PatentDe  


Dokumentenidentifikation EP0632855 08.07.1999
EP-Veröffentlichungsnummer 0632855
Titel KUNSTSTOFFSPULENHALTER MIT WIDERSTANDSFÄHIGEN ELEMENTEN
Anmelder Bakron Corp., Buffalo Grove, Ill., US
Erfinder BADILLO, Paul, Littleton, CO 80215, US
Vertreter derzeit kein Vertreter bestellt
DE-Aktenzeichen 69229357
Vertragsstaaten CH, DE, IT, LI
Sprache des Dokument En
EP-Anmeldetag 19.03.1992
EP-Aktenzeichen 929174746
WO-Anmeldetag 19.03.1992
PCT-Aktenzeichen US9200648
WO-Veröffentlichungsnummer 9319236
WO-Veröffentlichungsdatum 30.09.1993
EP-Offenlegungsdatum 11.01.1995
EP date of grant 02.06.1999
Veröffentlichungstag im Patentblatt 08.07.1999
IPC-Hauptklasse D05B 57/26

Beschreibung[en]

This invention relates to a bobbin basket for a lock-stitch sewing machine, and more particularly to a plastic bobbin basket that includes members to resist damage to the bobbin basket that might otherwise occur when the basket is used in the sewing machine.

BACKGROUND OF THE INVENTION

This invention complements the invention described and claimed in applicant's U. S. patent No. 4,858,543 issued August 22, 1989 and assigned to the assignee of the present invention. The bobbin basket covered by that patent is adapted for use with a horizontal rotary loop taker, which is the term used in the sewing machine industry for rotary loop takers or "hooks" that when installed in a lock-stitch sewing machine have a horizontal axis of rotation. The present invention is useful for any bobbin basket, whether it is adapted for use with a horizontal hook or with a vertical hook.

Prior to the invention disclosed and claimed in patent No. 4,858,543, bobbin baskets used in the industrial sewing machine industry were customarily made of metal, typically steel. Steel bobbin baskets have a number of disadvantages that have been recognized for a very long time. The invention covered by patent No. 4,858,543 took a big step toward providing a bobbin basket that avoids the problems associated with steel bobbin baskets, by providing a plastic bobbin basket of greatly increased usefulness and much longer life than was previously believed to be possible. The present invention goes still farther in increasing the usefulness of a plastic bobbin basket and extending its life.

The many advantages that a bobbin basket formed almost entirely of plastic has over a conventional all steel basket are clear. Molding of the basic plastic piece (with or without the small inserts of the present invention which are described below) is far more convenient and less expensive than the casting or forging -- followed by various machining, polishing and hardening steps -- that is involved in the production of an all steel bobbin basket. Chattering of the bearing rib in its raceway -- which produces chipping and burring, with resulting thread breakage -- is avoided with such a plastic bobbin basket. The lower coefficient of friction between the bearing rib and its raceway produces a longer life for the plastic bobbin basket, and avoids the problems of messy lubrication, galling, bluing of the rotary loop taker, and puckering of the goods being sewn that accompany the use of an all steel basket.

As already mentioned above, U. S. patent No. 4,858,543 took a big step towards making all these advantages available to the sewing industry. The present invention provides another highly significant advance toward eliminating various types of wear and impact damage that have over the years seemed to deter those skilled in the art from attempting to achieve the highly desirable but presumably impossible goal of a bobbin basket formed almost entirely of plastic.

A number of prior workers in this field have fabricated bobbin baskets partly of plastic and partly of metal, but none of them have utilized this approach to produce a bobbin basket that is formed almost entirely of plastic, as applicant does. Examples of the universal failure to realize that the many significant advantages of a bobbin basket formed almost entirely of plastic are capable of achievement are provided by U. S. patents No. 4,108,095 to Kohara, No. 4,377,121 to Teranishi, No. 4,393,798 to Cheng and No. 4,700,643 to Hirose et al. In 5 Kohara, bobbin carrier 32 is comprised of upper member 33, lower member 34 and intermediate member 35, with only the latter member being formed of molded plastic material (col. 2, lines 40-46). In Teranishi, bobbin case 12 is divided into an upper portion 13 made of metal, and a lower portion 14 made of plastic (col. 1, lines 58-60). Cheng's bobbin basket is made up of an upper part, a lower part, and a middle part that constitutes the bearing rib, with that rib being either formed of, or coated with, Teflon (col. 2, line 13). In Hirose et al., only track projection member 27 (the equivalent of a bobbin basket bearing rib) is made of synthetic resin material (col. 4, lines 22-24). It is evident that none of these prior workers in this field recognized the extreme value, or even the possibility, of fabricating a bobbin basket almost entirely of plastic.

U. S. patent No. 4,676,178 to Hirose deals with the problem of frictional wear between the bobbin basket bearing rib and its associated raceway by an entirely different, complicated and more expensive expedient -- the use of magnets embedded in the bearing rib and raceway with identical magnetic poles opposite each other to produce a repelling force that is expected to keep the rib and raceway from contacting each other. Whether or not this approach is useful in practical application, it is entirely different from applicant's invention.

SUMMARY OF THE INVENTION

Except that the bobbin basket of this invention is formed almost entirely of plastic, the basic configuration of the basket is conventional, including as it does a cylindrical side wall, a flange extending radially outward at the top of the cylindrical side wall with two portions of the flange shaped to form a rotation-restraining notch, and a bearing rib extending outwardly from the cylindrical wall.

The features added by this invention to that basic bobbin basket configuration include damage resistant members for reducing (1) wear on the two bearing rib end portions that together define the needle thread pick-up and release area, (2) wear on the portion of the flange that forms the downstream (relative to the direction of rotation of the rotary loop taker) rotation-restraining notch side wall with which the bobbin thread comes into contact as it exits from the bobbin spool, and (3) wear on the bearing rib body in spite of the contact that is maintained between the rib body and the rotary loop taker raceway in which the rib is journaled, and in addition include a member for minimizing impact damage to the upstream (relative to the direction of hook rotation) rotation-restraining notch side wall that periodically strikes the downwardly extending stud portion of the stationary positioning finger for the bobbin basket. Since the appended claims include subcombination claims to each of these means, the practice of this invention may involve only one, or any number, of these means.

Whatever number of the disclosed damage resistant members is utilized, damage to the plastic bobbin basket caused by wear or impact is correspondingly reduced or minimized. It is believed that under some conditions of operation, any such damage to the bobbin basket can be virtually eliminated through the use of this invention in all its features.

Each damage resistant member for reducing wear just mentioned, whether the wear involved is wear produced by friction or by abrasion, preferably comprises in each case at least one insert embedded securely within the bobbin basket element with which it is associated. The material of which each of these wear-reducing inserts is formed has a substantially lower coefficient of sliding friction, with the element with which it comes into contact in the sewing machine, than the main material of which the bobbin basket is formed does, or is substantially harder than that material, or has a substantially higher heat deflection temperature than that material, or can have any two or three of these properties. Each insert preferably has only a single portion of its exterior surface exposed, which exposed surface portion is smooth, free of sharp edges, and substantially flush with the surrounding surface of the element in which the insert is embedded. Preferred locations for these inserts are disclosed.

At least one portion of the exterior surface of each of said wear-reducing inserts is exposed to contact with a curved, elongated area of the needle thread loop, rotary loop taker raceway, or bobbin thread with which it is associated. Each of these exposed surface portions is smooth and free of sharp edges. In addition, the lengthwise radius of curvature of each of said exposed surface portions of the wear-reducing inserts is no greater than -- in other words, is equal to or less than -- the radius of curvature of the immediately surrounding surface of the bobbin basket element with which it is associated.

The member for minimizing impact damage to the upstream side wall of the rotation-restraining notch in the flange at the top of the cylindrical side wall of the bobbin basket of this invention comprises a member securely attached to that side wall. This member preferably has at least one surface exposed to impact from the stud portion of the stationary positioning finger for the bobbin basket. The member is formed of a material that has a substantially higher impact strength than the main material of which the bobbin basket is formed does. This damage resistant member may be an insert securely embedded in the rotation-restraining notch side wall in question. In such case, it is preferred that the insert protrudes a short distance from the surface of the side wall in which it is embedded, and this protruding portion is desirably rounded in shape.

The area occupied by each of the members described for reducing wear or minimizing impact damage falls in the range from a small fraction of the potential area of the wear or impact damage to the entire area of such potential wear or damage.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in detail below with reference to the accompanying drawings, in which:

  • FIG. 1 is a top plan view of one embodiment of the bobbin basket of this inventionadopted for use with a horizontal rotary loop taker in a sewing machine that is equipped with an under trimmer;
  • FIG. 2 is a side elevation of the embodiment of FIG. 1 as seen when looking at that embodiment from the top of the latter Figure;
  • FIG. 3 is an enlarged, fragmentary view of the end portion of the bearing rib that is seen on the right hand side of FIG. 2;
  • FIG. 4 is a sectional view of the fragmentary showing of FIG. 3 taken along line 4-4 in the latter Figure, which provides a bottom plan view of the bearing rib that is seen in FIG. 3;
  • FIG. 5 is a side elevation of another embodiment of the bobbin basket of this invention that is similar to the embodiment of FIGS. 1-4 but has a different form of needle guard plate and is not adapted for use with an undertrimmer, showing the stud carried by the bobbin basket positioning finger inserted in its operative position in the rotation-restraining notch of the bobbin basket;
  • FIG. 6 is a fragmentary top plan view of the portion of the embodiment of FIG. 5 that is nearest the viewer in the latter Figure; and
  • FIG. 7 is a developed view of the side wall of the bearing rib of a bobbin basket according to this invention that includes wear-reducing inserts spaced alternately at the top and bottom of the bearing rib.

DETAILED DESCRIPTION OF BEST MODE

A detailed description of the best mode of practicing the present invention will now be provided by reference to the drawings.

General Configuration of Bobbin Basket

Plastic bobbin basket 20, seen in top plan view in FIG. 1, includes cylindrical side wall 22, crosswise support member 24, extending across the bottom of the bobbin basket, bobbin spool support post 26 extending axially from support member 24 into the space defined by side wall 22, and flange 28 extending radially from the top portion of the side wall.

Portions 28a and 28b of flange 28 form oppositely facing side walls 30a and 30b that are positioned generally radially to form rotation-restraining notch 32 in the top surface of flange 28. First notch side wall 30a forms the downstream side of rotation-restraining notch 32, relative to the direction of rotation 31 (in FIG. 1, counterclockwise) of the rotary loop taker with which bobbin basket 20 is adapted to be used. Second notch side wall 30b forms the upstream side, relative to the direction of hook rotation, of rotation-restraining notch 32. Notch 32 is adapted to receive the stud portion of the stationary positioning finger (shown in FIG. 5) with a secure but sufficiently loose fit to permit limited back-and-forth rotational movement of the bobbin basket.

A second notch 33 is provided at the inside perimeter of flange 28, on the right-hand side of FIG. 1. In use, a projection from the bobbin case which contains the bobbin spool is seated in this notch to align the case properly and to keep the case from rotating on post 26.

Annular bearing rib 34 extends radially outward from cylindrical side wall 22. It is located at the midportion of side wall 22 between flange 28 at the top of the bobbin basket and the bottom of the basket. A portion of annular rib 34 is omitted at 36 to provide two oppositely facing rib end portions 38 and 40 that define a needle thread pick-up and release area.

Rib end portion 38 forms "V"-shaped pick-up notch 42 at the downstream end, relative to direction of hook rotation 31, of the needle thread pick-up and release area. Rib end portion 40, located adjacent rotation-restraining notch 32, forms needle thread stop 44 at the upstream end, again relative to the direction of hook rotation, of the needle thread pick-up and release area.

Except that all the members mentioned just above are integrally formed of plastic, the configuration of bobbin basket 20 as thus far described is conventional.

Needle guard plate 43 in FIG. 2 is of the type disclosed and claimed in applicant's previously issued U. S. patent No. 4,858,543 referred to above. It is included in the illustrated plastic bobbin basket to prevent damage to cylindrical wall 22 if a needle used with the horizontal hook with which this basket is adapted to be used should be accidentally deflected downward as it moves forward to enter needle-receiving space 45. (Plate 43 is omitted from FIG. 1 for clarity,)

Guard plate 100 in FIGS. 5 and 6 is a different form of the needle guard plate which is illustrated in FIG. 4a of U. S. patent No. 4,858,548. It prevents damage to the cylindrical side wall of the bobbin basket of FIGS. 5 and 6 if the needle does not properly enter needle-receiving space 102. Plate 100 is secured to cylindrical side wall 22' of bobbin basket 20' (1) by embedded portion 104, (2) by embedded pins 106 with enlarged inner ends 108 and (3) by adhesive bonding.

Wear on Needle Thread Stop

Bearing rib 34 includes means for reducing wear on the needle thread stop that is formed by rib end portion 40, as needle thread loop 41 comes into contact with the stop and the thread is pulled forcefully across the stop to move it into position to tighten the loop around the bobbin thread. In the embodiment of FIG. 1, this wear-reducing means comprises cylindrical insert 44 embedded securely within rib end portion 40. Insert 44 is also embedded within cylindrical side wall 22, with its inner end 46 enlarged to provide a more secure attachment.

As best seen in FIG. 2, portion of 44a of the cylindrical exterior surface of insert 44 is substantially flush with the surrounding surface 40a of rib end portion 40, but is still exposed slightly to reduce wear on the end surface of the needle thread stop as thread 41 comes into contact with the stop and is thereafter pulled up across the stop to tighten the needle thread around the bobbin thread.

In the embodiment of FIGS. 5 and 6, insert 44' is embedded in the needle thread stop formed by end portion 40 of bearing rib 34'.

Wear on Needle Thread Pick-Up Notch

Inserts for reducing wear on rib end portion 38, which with side wall 22 forms "V"-shaped pick-up notch 42, are included in the embodiment of the bobbin basket of this invention that is illustrated in FIGS. 1 through 4. In the operation of the sewing machine, the needle thread loop is caught in notch 42 and moves longitudinally across the notch as the rotary loop taker rorates and enlarges the loop.

As best seen in FIGS. 3 and 4, outer part 38a of rib end portion 38 extends in a circumferential direction to form pick-up notch 42 with cylindrical side wall 22. As the hook rotates around the bobbin basket, needle thread loop 41 is caught by this pick-up notch.

As shown in this embodiment, wear-reducing insert 52 is embedded partly in side wall 22 of the bobbin basket, and partly in rib end portion 38, in the vicinity of the bottom of "V"-shaped pick-up notch 42. Again, as with wear-reducing insert 44 described above, inner end 54 of insert 52 is enlarged to produce a more secure embedding in side wall 22, and exposed outer end 56 of this insert is substantially flush with the surrounding portion 58 of the outer side wall of rib end portion 48.

As shown in FIGS. 3 and 4, in this embodiment outer end 38a of rib end portion 38 is tapered slightly inward at the end portion of bottom side 38b of the rib. Second wear-reducing insert 60 is securely embedded partly in bobbin basket side wall 22, and partly in rib end portion 38, in the vicinity of the beginning of the tapered end section of rib portion 38.

Enlarged portion 62 of this insert helps to provide a secure attachment of the insert to side wall 22. Here, again, as with portion 44a of insert 44 described above, a portion 64 of the cylindrical exterior surface of insert 60 is exposed to contact with needle thread 41. Outer end 66 of insert 60 can, if desired, be flush with the outer side wall of rib end portion 38, but in this embodiment the insert terminates within the bearing rib.

In the embodiment of FIGS.5 and 6, tapered rib end portion 38a' forms needle thread pick-up notch 42' with cylindrical side wall 22'. This embodiment includes only one embedded inser to reduce wear at the pick-up notch, which is insert 52'.

Impact Damage on Wall of Rotation-Restraining Notch

As shown in FIGS. 1 and 2, insert 70 is securely embedded in upstream side wall 30b of rotation-restraining notch 32 that is formed by flange portion 28b. In this embodiment, insert 70 protrudes a short distance beyond the surrounding surface of side wall 30b. Outer end 72 of insert 70 is in this embodiment rounded in shape.

Although end 72 is shown as protruding beyond the surrounding surface of the flange portion in which it is embedded, if desired the insert may be flush with that surrounding surface or even buried slightly below the surface with no part exposed. In any such case, the outer end 72 of the insert is preferably a flat surface.

Insert 70 acts to minimize impact damage to wall 30b that would otherwise be caused by the stud portion of the stationary positioning finger (best seen in FIG. 5) as bobbin basket 20 is jerked back and forth by the needle thread loop to cause wall 30b to strike the stud repeatedly as tension is applied to the thread of the needle thread loop first in one direction and then in the other. Insert 70 may be formed of any material that has a substantially higher impact strength than the main material of which bobbin basket 20 is formed does. A steel insert, for example, has been found to be suitable for use in this insert to minimize impact damage as described.

The means for minimizing impact damage to the upstream side wall of rotation-restraining notch 32 may be a member of any suitable shape, and may or may not be embedded in flange portion 28b. A rectangular plate of suitable size may, for example, be bonded to the surface of wall 30b or secured to the wall by a protuberance on the back of the plate that is embedded in the wall.

In the embodiment of FIGS. 5 and 6, the impact damage-minimizing member is insert 70' securely embedded in flange portion 28b' on the upstream side (relative to the direction of hook rotation) of rotation-restraining notch 32'. During operation of the sewing machine, wall 120 of stud 122 is struck by pin 70' as bobbin basket 20' is jerked back and forth by the needle thread.

Wear on Rib Body

In addition to the frictional and abrasive wear that can occur at the needle thread stop and the pick-up notch at rib end portions 38 and 40, respectively, there may be wear from the frictional contact between the entire body of bearing rib 34 and the raceway on the inner wall of the rotary loop taker in which the rib is journaled as the hook rotates around the basket. Applicant has discovered that it is not necessary to pay special attention to the entire body of the rib by selecting a particular material by which it is formed or coated, but it is sufficient to space a plurality of inserts around the extent of the rib body.

In the embodiment of FIGS. 1 and 2, inserts 44 and 52 already described above are utilized for this purpose. In this embodiment, three additional inserts 80 are spaced along the extent of bearing rib 34. Each of those additional inserts has its outer end 82 exposed and substantially flush with, and having the same cylindrical shape as the outer side wall of the bearing rib. As a result, inserts 44, 52 and 82 all function to reduce the frictional wear between the outer wall of bearing rib 34 and the raceway. If desired, inserts 44, 52 and 82 may have outer ends that are rounded in shape and protrude slightly from the bearing rib.

If it is desired to use only two inserts to reduce wear on the outer wall of the rib body, insert 44 need not be extended to expose its outer end to contact with the raceway, and a single insert with an exposed outer end can be positioned diametrically opposite insert 52. It is preferred, however, to have several inserts equally spaced about the perimeter of the bearing rib.

In the embodiment of FIGS. 5 and 6, inserts 44' and 52' (which are omitted for clarity from FIG. 6) cooperate with a plurality of inserts 80' embedded in bearing rib 34', with exposed outer ends 82' spaced along the extent of the rib, to reduce wear on the plastic bearing rib caused by the contact of the rib with the raceway of the metal rotary loop taker in which the rib is journaled.

Figure 7 shows a developed view of the outer wall of bearing rib 34", with tapered rib end portion 38a" forming a needle thread pick-up notch (on the lefthand side of the Figure) and rib end portion 40" forming a needle thread stop at the opposite end. In this embodiment, cylindrically shaped inserts 130 are spaced along, and embedded in, bearing rib 34" with upwardly facing, slightly exposed, cylindrical surfaces that are substantially flush with the surface of upper wall 132 of the bearing rib. Cylindrically shaped inserts 134 are embedded in rib 34" in the same way as inserts 130 except that they have downwardly facing, slightly exposed, cylindrical surfaces substantially flush with the surface of bottom wall 136 of the bearing rib. Inserts 130 and 134 alternate along the length of the bearing rib.

If it is positioned diametrically opposite to wear-reducing inserts such as members 44' and 52' in FIG. 5, even a single insert such as insert 130 or 134 will have an appreciable effect in reducing wear on the body of the bearing rib. It is preferred, however, to employ several such inserts, equally spaced along the bearing rib.

If desired, one or more of cylindrically shaped insert 130 embedded in the bearing rib 34" may be positioned parallel to the outer wall of the bearing rib, in which case any such inserts may have flat, exposed end surfaces facing both up and down, to reduce wear on the upper and lower surfaces, respectively, of the bearing rib, with which they are substantially flush.

Wear on Flange Portion That Defines Downstream Side of Rotation-Restraining Notch

In the embodiment of FIGS. 1 and 2, downstream side wall 30a of rotation-restraining notch 32 is a of a reentrant type that provides a recessed groove 90 for the passage of the bobbin thread as it exits from the bobbin spool in a sewing machine of the undertrimmer type.

As the bobbin thread is paid out from the bobbin spool, usually through a hole in the container in which the spool is encased, it travels past inner wall 92 of recessed groove 90 of side wall 30a of the rotation-restraining notch. In the embodiment of FIGS. 1 and 2, cylindrical wear-reducing insert 94 is positioned at the innermost end of inner wall 92 of recess 90. In this embodiment a small part 96 of the cylindrical exterior surface of insert 94 is exposed in the vicinity of the junction between inner walls 92 and 22a of recessed groove 90 and bobbin basket cylindrical side wall, respectively.

The embodiment of FIGS. 5 and 6 is not used with a sewing machine having an undertrimmer, and hence the downstream wall of rotation-restraining notch 32', which is formed by flange portion 28a, does not have any recessed groove at the bottom of the notch. There will still be wear that should preferably be guarded against on the flange portion, member 28a' in these Figures, that define the downstream side of rotation-restraining notch 32'. In this embodiment, flange portion 28a' defines bobbin thread groove 140 in its top surface. Groove 140 is oriented in direction 142, the direction in which the bobbin thread moves as it leaves the bobbin spool (not shown). Wear-reducing inserts 144 and 146 are embedded in flange portion 28a' at the bottom of groove 140 at the entry and exit ends, respectively, of the groove. The exposed top ends of inserts 144 and 146 have the same shape as the bottom of groove 140 and are flush with the groove bottom wall.

This fifth type of damage resistant member is believed to be the least important of those that have been discussed as elements of the plastic bobbin basket of this invention.

Further Properties of Damage Resistant Members

Several properties are common to the various damage resistant members that are described above.

Surprisingly, applicant has discovered that it is not necessary to provide damage resistant members that protect the entire area of potential wear or damage of a given type. Thus it is not necessary, for instance, to do as various prior art workers have done and form, or cover, the entire bearing rib of a bobbin basket with a selected plastic. It is only necessary to provide damage resistant members for a small fraction of the area that is identified as one in which damage may occur during use of the bobbin basket. As is shown by the various Figures of the accompanying drawings, the area occupied by each of the damage resistant members described above may fall in the range from a small fraction of the potential area of wear or impact damage to the entire area of potential wear or damage.

It will also be observed from the accompanying drawings that at least one portion of the exterior surface of each of the wear-reducing inserts described above is exposed to contact with a curved, elongated area of the needle thread loop, rotary loop taker raceway, or bobbin thread with which it is associated. Each of said exposed surface portions is smooth and free of sharp edges. Moreover, the accompanying drawings show that the lengthwise radius of curvature of each of said exposed surface portions is no greater than the radius of curvature of the immediately surrounding surface of the bobbin basket element with which it is associated. Thus, it will be noted from FIG.2 that the radius of curvature of exposed surface portion 44a is either equal to or somewhat smaller than the radius of curvature of the immediately surrounding surfaces, which are end surface 40a and bottom surface 40b of end portion 40. Likewise, from FIG. 3 it will be noted that the radius of curvature of wear-reducing insert 52 is substantially smaller than the radius of curvature of bottom 42a of pick-up notch 42. Similarly, it will be noted from FIG. 1 that the radius of curvature of exposed end surface 82 of each wear-reducing insert 80 is equal to the radius of curvature of outer wall 34a of bearing 34, and that the radius of curvature of the exposed exterior surface portion 96 of wear-reducing insert 94 is substantially less than the radius of curvature of the surrounding surfaces of inner wall 92 of recessed groove 90 and inner surface 22a of cylindrical side wall 22.

All the inserts for reducing wear at various locations in bobbin basket 20 that are described above may be formed of any suitable material that will resist either frictional or abrasive wear. The material may have a substantially lower coefficient of sliding friction, with the needle thread, rotary loop taker raceway and bobbin thread with which it is in contact during use in the sewing machine, than the main material of which bobbin basket 20 is formed has, or may be substantially harder than that material, or may have a substantially higher heat deflection temperature than that material, or may have any two or three of these properties. Suitable materials include ceramic, steel, carbide, a non-moldable plastic or the like, with ceramic being preferred.

In selecting the material to use in making the above described inserts for reducing wear on various parts of the bobbin basket that is caused by contact with the needle thread loop or bobbin thread, consideration must be given to the type of thread with which the bobbin basket is to be used, and in addition to the type of sewing machine on which it is to be used. Some threads will have higher coefficients of sliding friction with the part of the plastic bobbin basket, and with the exposed portions of the damage resistant member that they contact, than other threads do. Some threads will be more abrasive than others. The speed at which the sewing machine will be operated will of course affect the likelihood of wear from either friction or abrasion.

As already indicated above, the material of which the means for minimizing impact damage to the downstream side wall of the rotation-restraining notch is formed may be any material that has a substantially higher impact strength than the main material of which bobbin basket 20 is formed does.

Method of Manufacture of Inserts

Depending upon the particular sewing machine with which the bobbin basket is to be used and the conditions under which the machine will be used, all or any number of the damage resistant means that comprise the plastic bobbin basket of this invention may be included in the basket.

The various wear-reducing inserts described above can be positioned in the mold in which the main portion of the plastic bobbin basket is to be produced, and the bobbin basket can be molded around those inserts.

On the other hand, if desired the plastic bobbin basket may be first molded in its entirety, and thereafter holes bored in the resulting product with the desired inserts then secured in the holes, either adhesively bonded or with a tight fit or press fit that will insure that they remain in place during use of the bobbin basket. If any exposed surfaes of the inserts do not already have the desired shape when installed in place, they can then be machined, ground or polished to a surface that is flush with, and preferably has the same cross-sectional shape as, the surface of the member surrounding that exposed surface. Surface 56 of insert 52 and surfaces 82 of inserts 80, for example, can be treated to form surfaces that are continuations of (or blend smoothly with) the curvilinear surfaces that surround them. The same can usually be done for the exposed surfaces of other inserts.


Anspruch[de]
  1. Ein Spulenhalter oder Spulenkorb (20) für einen drehenden Schleifennehmer bei einer Sperrstich-Nähmaschine, enthaltend:
    • eine zylindrische Seitenwand (22), ein sich quer über den Boden des Spulenkörpers erstreckende Stütze (24) oder Traverse, einen Tragstift (26) für eine Spulenrolle, der sich von der Traverse (24) in den von der Seitenwand (22) umschlossenen zylindrischen Raum erstreckt,
    • ein Flansch oder Rand (28) erstreckt sich radial ausserhalb des oberen Bereiches der zylindrischen Seitenwand (22), zwei Teile oder Bereiche (28a, 28b) des Flansches (28) bilden einander gegenüberliegende erste und zweite Seitenwände oder Stirnflächen (30a, 30b), die generell radial positioniert sind zur Bildung einer Drehbegrenzungskerbe (32) in der Oberseite des Randes (28); die erste Stirnwand (30a), bildet die stromab- bzw. fadenabwärtige Seite der Drehbeschränkungskerbe (32) relativ zu der Drehbewegung des Schleifennehmers, an welchen der Spulenkorb angepasst ist; die zweite Stirnfläche 30b bildet die fadenaufwärtige Seite der Beschränkungskerbe (32) bezüglich der Drehrichtung, die Kerbe (32) ist vorgesehen zur Aufnahme des Stutzenteils oder Eingriffsteils eines stationären Positionierfingers mit sicherer, aber ausreichend lockerer Passung für eine beschränkte Vor- und Zurückdrehung des Spulenkorbes (20) und
    • eine ringförmige Tragrippe (34) streckt sich von der Seitenwand (22) radial nach aussen, die Tragrippe (34) ist vorgesehen zwischen dem sich nach aussen erstreckenden Rand (38) und dem Boden des Spulekorbes (20) und erstreckt sich im Wesentlichen über den ganzen Umfang des Spulenkorbes (20), mit Ausnahme eines geringen Bereiches, der ausgelassen ist zur Bildung zweier einander gegenüberliegender, rippenförmiger Endteile (38, 40), die einen Bereich zum Fangen und Freigeben des Nadelfadens bilden,
    • der erste der Rippenendteile (38) bildet eine Aufnahme- oder Fangkerbe (42) an dem fadenabseitigen Ende des Nadelfadenaufnahme- und -freigabebereiches, relativ zu der Drehbewegung des drehenden Fadennehmers, mit dem der Spulenkorb zusammenarbeitet, und
    • der zweite der einander gegenüberliegenden Rippenendteil (40) ist lokalisiert benachbart der Drehbeschränkungskerbe (32) zur Bildung eines Nadelfadenanschlags- oder -stops (44) an der fadenaufseitigen Seite des Nadelfadenfang- und -freigabebereiches, relativ zu der Drehbewegungsrichtung, und
    dadurch gekennzeichnet, dass:
    • (a) der Spulenkorb (20), einschliesslich seiner zylindrischen Wandung (22), des nach auswärts sich erstreckenden Randes (28) und der sich nach auswärts erstreckenden Tragrippe (34) ist einstückig aus Plastik hergestellt, und
    • (b) die Tragrippe (34) weist Mittel (44) auf zur Verschleissminderung an dem zweiten, stromaufwärtigen Rippenende, welches den Nadelanschlag bildet, wenn der Nadelfaden in Kontakt mit dem Anschlag kommt, wobei der Faden kräftig über den Anschlag gezogen wird, um die Schleife um die Spule herum festzuziehen,
    • (c) die Tragrippe (34) weisst Mittel zur Verschleissminderung auf an dem ersten, fadenabseitigen Rippenende, welches die vorerwähnte Fangkerbe bildet, wenn die Nadelfadenschleife in der Kerbe gefangen wird und sich axial über die Kerbe bewegt, während der Schleifenfinger rotiert und die Schleife vergrössert,
    • (d) die zweite, fadenaufseitige Wandung (30b) der Drehbeschränkungskerbe (32) hat Mittel (70) zur Minimierung von Prallschäden an der zweiten Wandung (30b), welche verursacht werden durch den Eingriffsteil des stationären Positionierungsfingers, wenn der Spulenkopf (20) von der Nadelfadenschleife kräftig vor- und zurückgeschleudert wird, wobei die zweite Wandung (30b) wiederholt diesen Stutzen anschlägt, wenn Spannung ausgeübt wird auf den Faden innerhalb der Schleife erst in einer Richtung und dann in der anderen Richtung,
    • (e) die Tragrippe (34) weist Mittel zur Verminderung des Verschleisses auf, der durch die Drehung der Fadenfängerlaufbahn, in welcher die Rippe rotiert, verursacht wird, während gleichzeitig wesentlicher Kontakt aufrecht erhalten wird zwischen der Laufbahn und dem Rippenkörper mit den Verschleissverhinderungsmassnahmen, und
    • (f) der Bereich, der eingenommen wird von jedem der Mittel zur Reduzierung von Verschleiss oder Minimierung von Prallschäden an einer gegebene Stelle des Spulenkorbes, erstreckt sich von einem kleinen Bruchteil des potentiellen Verschleissgebietes oder des Prallschadens an der jeweils gegebenen Örtlichkeit bis über das gesamte mögliche, potentielle Verschleiss- oder Schadensgebiet innnerhalb dieser örtlichkeit.
  2. Der Spulenkorb (20) aus Kunststoff nach Anspruch 1, wobei:
    • (a) die Mittel (44) zur Verschleissminderung an den bewegungsstromaufwärtigen und bewegungsstromabwärtigen Rippenendteilen und an dem Rippenkörper umfassend wenigstens einen Einsatz, der sicher eingebettet ist in das Element des Spulenkörpers, zu dem es gehört, und
    • (b) die Mittel (70) zur Minimierung von Prallschäden an der zweiten bewegungsstromaufwärtigen Seitenwand der Drehbeschränkungskerbe (32) umfassen ein Teil oder Glied, welches an diesem zweiten Seitenwandteil (30b) angebracht ist.
  3. Der Spulenkorb aus Kunsstoff nach Anspruch 2, wobei:
    • (a) wenigstens ein Teil der äusseren Oberfläche jedes der besagten verschleissmindernden Einsätze (44) ist ausgesetzt dem Kontakt mit einem kurvigen oder gewölbten, länglichen Bereich der Nadelfadenschleife oder der drehbaren Schleifenfängerlaufbahn, zu der er (der Einsatz) gehört, jede der dem Verschleiss oder Schaden ausgesetzte Oberflächen ist glatt und frei von scharfen Kanten, der Kurvenradius in Längsrichtung der dem Verschleiss ausgesetzten Flächen ist nicht wesentlich grösser als der Kurvenradius der unmittelbar umgebenden Oberflächenbereiche des zugehörigen Elementes des Spulenkorbes, und
    • (b) wenigstens ein Teil der äusseren Oberfläche des schadensminimierenden Teiles (70) ist ausgesetzt der Prallwirkung des Stützenteils od.er Eingriffsteils des stationären Positionierungsfingers.
  4. Der Spulenkorb aus Plastik nach Anspruch 3, wobei:
    • (a) der radial äussere Teil des in Bewegungsrichtung unteren oder hinteren Rippenendteils (38) erstreckt sich in Umfangsrichtung derart, dass mit der Seitenwandung (22) des Spulenkorbes eine Aufnahmekerbe oder Aufnahmenut für die Nadelfadenschlinge gebildet wird, diese Nut hat eine "V"-Gestalt in axialer Draufsicht auf die Drehachse, und
    • (b) der Einsatz oder Verschleiss-Stift (52) zur Verschleissminderung ist eingebettet einerseits in die Seitenwandung (22) des Spulenkorbes und andererseits in den Rippenendteil (38), nahe dem Boden der "V"-förmigen Kerbe.
  5. Der Spulenkorb aus Plastik nach Anspruch 4, wobei:
    • (a) das sich in Umfangsrichtung erstreckende, bewegungsstromabwärtige Rippenteil (38) ist nahe dem Boden des Tragringes (34) leicht nach innen verjüngt, und
    • (b) ein zweiter Einsatz zur Verschleissminderung ist eingesetzt, teils in die Seitenwandung (22) des Spulenkorbes und teilweise in den Rippenendteil (38), nahe des Beginns des verjüngten Teils des Rippenendes.
  6. Der Spulenkorb nach Anspruch 3, 4 oder 5, versehen mit einer Vielzahl von Einsätzen zur Verschleissminderung, eingesetzt in den Körper der ringförmigen Tragrippe (34).
  7. Der Spulenkorb nach Anspruch 6, weiter enthaltend wenigstens einen Einsatz zur Verschleissminderung an dem ringförmigen Körper, der eine nach auswärts gerichtete Oberfläche hat, die im Wesentlichen bündig ist mit der Oberfläche der äusseren Wandung des Tragrippenkörpers (34).
  8. Der Spulenkorb aus Plastik nach Anspruch 6, weiter versehen mit wenigstens einem Einsatz zur Verschleissminderung an dem Körper (34) der ringförmigen Tragrippe mit einer nach oben weisenden Verschleissfläche, die im Wesentlichen bündig ist mit der oberen Wandung oder Oberfläche des Tragrippenkörpers.
  9. Der Spulenkorb aus Plastik nach Anspruch 6, weiter versehen mit wengistens einem Einsatz zur Verminderung von Verschleiss an dem ringförmigen Tragrippenkörper (34), der eine nach unten weisende Verschleissfläche aufweist, die im Wesentlichen bündig ist mit der Oberfläche des Tragrippenkörpers.
  10. Der Spulenkorb aus Kunsstoff nach Anspruch 6, weiter enthaltend eine Vielzahl von Einsätzen zur Verschleissverminderung an dem ringförmigen Tragrippenkörper (34) im Abstand über die Erstreckung der Tragrippe, mit benachbarten Verschleissflächen abwechselnd an der oberen und unteren Oberfläche der Tragrippe (34) und wobei weitere Verschleissflächen an der Oberfläche der äusseren Wandung des Tragrippenkörpers nach auswärts gerichtet sind.
  11. Der Spulenkorb nach irgendeinem der vorausgehenden Ansprüche, wobei der Teil des Flansches oder Randes (28), der die in Bewegungsstromrichtung untere Wandung (30a) der Drehbegrenzungskerbe (32) bildet, Mittel zur Minderung von Verschleiss an diesem Teil des Flansches aufweist, der verursacht wird durch Kontakt mit dem von der Fadenspule ablaufenden Faden, wobei die von diesen Verschleissmitteln eingenommene Fläche an dieser ersten Wand sich in dem Bereich von einem kleinen Teil der potentiell verschleissgefährdeten Fläche bis über den gesamten verschleissgefährdeten Bereich erstreckt.
  12. Der Spulenkorb nach Anspruch 11, wobei:
    • (a) das Mittel zur Verschleissminderung an dem Teil des Flansches oder Randes, der den besagten ersten, bewegungsstromunterseitige Wandung der Drehbeschränkungskerbe bildet, gebildet ist von wenigstens einem sicher in diesen Flansch oder Rand eingebetteten Einsatz, und
    • (b) das Mittel (70) zur Minimierung des Schadens an der zweiten bewegungsstromoberseitigen Wandung der Drehbeschränkungskerbe umfasst ein an der zweiten Wandung festgemachtes Teil.
  13. Der Spulenkorb aus Kunststoff nach irgendeinem der vorhergehenden Ansprüche, wobei wenigstens ein Teil der äusseren Oberfläche jedes der verschleissmindernden Mittel dem Kontakt mit einem kurvigen, oder gewölbten länglichen Bereich der Nadelfadenschleife oder des rotierenden Schleifenfängerlaufweges ausgesetzt ist, dem es zugehört; jeder der dem Verschleiss ausgesetzten oder exponierten Oberflächenbereiche ist glatt und frei von scharfen Kanten, der Kurvenradius in Längsrichtung jeder der Verschleissflächenteile ist nicht wesentlich grösser als der Kurvenradius der unmittelbar umgebenden Oberfläche des zugehörigen Elementes des Spulenkorbes.
  14. Der Spulenkorb nach Anspruch 11 oder 12, wobei die Mittel zur Verminderung von Verschleiss an dem Flanschteil oder Randteil, der verursacht ist durch Kontakt mit dem Spulenfaden beim Abwickeln von der Spule, wenigstens einen Teil seiner äusseren Oberfläche aufweist, der ausgesetzt ist dem Kontakt mit einem kurvigen oder gewölbten, länglichen Bereich des zugehörigen Spulenfadens, wobei jede der Verschleissflächen glatt und frei von scharfen Kanten ist, der Kurvenradius der unmittelbar umgebenden Oberfläche des Flansches oder Randes, der die erste, bewegungsstromabseitige Wandung der Drehbeschränkungsnut bildet, ist im Wesentlichen nicht grösser als der Kurvenradius der benachbarten Teile des Spulenkorbs.
Anspruch[en]
  1. A bobbin basket 20 for use with a rotary loop taker in a lock-stitch sewing machine, which comprises:
    • a cylindrical side wall 22, a crosswise support member 24 for the cylindrical side wall 22 extending across the bottom of the bobbin basket, a bobbin spool support post 26 extending axially from said crosswise support member 24 into the space defined by said cylindrical side wall 22,
    • a flange 28 extending radially outward from the top portion of said cylindrical side wall, two portions 28a, 28b of said flange forming first and second oppositely facing side walls 30a, 30b that are positioned generally radially to form a rotation-restraining notch 32 in the top surface of the flange 28, said first notch side wall 30a forming the downstream side of the rotation-restraining notch 32 relative to the direction of rotation of the rotary loop taker with which the bobbin basket is adapted to be used, said second notch side wall 30b forming the upstream side of said rotation-restraining notch 32 relative to said direction of rotation, said notch 32 being adapted to receive the stud portion of a stationary positioning finger with a secure but sufficiently loose fit to permit limited back and forth rotational movement of the bobbin basket 20, and
    • an annular bearing rib 34 extending radially outward from said cylindrical side wall 22, said rib 34 being located between the aforesaid outwardly extending flange 28 and the bottom of the bobbin basket 20 and extending substantially around the perimeter of the bobbin basket 20 except for a minor portion of said annular rib 34 that is omitted to provide two oppositely facing rib end portions 38, 40 that define a needle thread pick-up and release area,
    • the first of said oppositely facing rib end portions 38 forming a pick-up notch 42 at the downstream end, relative to the aforesaid direction of rotation of the rotary loop taker with which the bobbin basket is adapted to be used, of the needle thread pick-up and release area, and
    • the second of said oppositely facing rib end portions 40 being located adjacent said rotation-restraining notch 32 to form a needle thread stop 44 at the upstream end, relative to said direction of rotation, of the needle thread pick-up and release area, and
       characterised in that:
    • (a) the bobbin basket 20, including said cylindrical side wall 22, said outwardly extending flange 28 and said outwardly extending bearing rib 34, is integrally formed of plastic, and
    • (b) said bearing rib 34 includes means 44 for reducing wear on said second, upstream rib end portion that forms the aforesaid needle thread stop, as the needle thread loop comes into contact with said stop, the thread is pulled forcefully across the stop to tighten the loop around the bobbin thread,
    • (c) said bearing rib 34 includes means for reducing wear on said first, downstream rib end portion that forms the aforesaid pick-up notch, as the needle thread loop is caught in said notch and moves axially across the notch as the rotary loop taker rotates and enlarges the loop,
    • (d) said second, upstream side wall 30b of the rotation-restraining notch 32 includes means 70 for minimising impact damage to said second side wall 30b caused by the aforesaid stud portion of the stationary positioning finger as the bobbin basket 20 is jerked back and forth by the needle thread loop to cause said second side wall 30b to strike said stud repeatedly as tension is applied to the thread of the needle thread loop first in one direction and then in the other,
    • (e) said bearing rib 34 includes means for reducing wear on the rib body caused by the rotary loop taker raceway in which the rib is journaled, while at the same time substantial contact is maintained between the raceway and the rib body including said wear-reducing means, and
    • (f) the area occupied by each of said means for reducing wear or minimising impact damage at a given location on the bobbin basket falls in the range from a small fraction of the potential area of wear or impact damage at that given location to the entire area of potential wear or damage at that location.
  2. The plastic bobbin basket 20 of claim 1 in which:
    • (a) said means 44 for reducing wear on said upstream and downstream rib end portions and on said rib body comprises at least one insert embedded securely within the bobbin basket element with which it is associated, and
    • (b) said means for minimising impact damage 70 to the second, upstream side wall of the rotation-restraining notch 32 comprises a member secured to said second side wall 30b.
  3. The plastic bobbin basket of claim 2 in which:
    • (a) at least one portion of the exterior surface of each of said wear-reducing inserts 44 is exposed to contact with a curved, elongated area of the needle thread loop or rotary loop taker raceway with which it is associated, each of said exposed surface portions being smooth and free of sharp edges, the lengthwise radius of curvature of each of said exposed surface portions being not substantially greater than the radius of curvature of the immediately surrounding surface of the bobbin basket element with which it is associated, and
    • (b) at least one portion of the exterior surface of said impact damage-minimising member 70 is exposed to impact from the stud portion of said stationary positioning finger.
  4. The plastic bobbin basket of claim 3 in which:
    • (a) the radially outer part of said downstream rib end portion 38 extends circumferentially to form with the side wall 22 of the bobbin basket 20 a pick-up notch for the needle thread loop, said notch having a "V"-shape in a plane perpendicular to the axis of rotation of the associated rotary loop taker, and
    • (b) an insert to reduce wear is embedded partly in the bobbin basket side wall 22, and partly in the rib end portion 38, in the vicinity of the bottom of said "V"-shaped notch.
  5. The plastic bobbin basket of claim 4 in which:
    • (a) said circumferentially extending downstream rib end portion 38 is tapered slightly inward adjacent the end of the bottom side of the bearing rib 34, and
    • (b) a second insert to reduce wear is embedded partly in the bobbin basket side wall 22, and partly in the rib end portion 38, in the vicinity of the beginning of said tapered portion of said rib end portion.
  6. The plastic bobbin basket of claim 3, 4 or 5 which includes a plurality of inserts to reduce wear embedded in the body of the annular bearing rib 34.
  7. The plastic bobbin basket of claim 6 which includes at least one insert for reducing wear on said annular rib body that has an outwardly facing exposed surface that is substantially flush with the surface of the outer wall of the bearing rib body 34.
  8. The plastic bobbin basket of claim 6 which includes at least one insert for reducing wear on said annular bearing rib body 34 that has an upwardly facing exposed surface that is substantially flush with the surface of the upper wall of the bearing rib body.
  9. The plastic bobbin basket of claim 6 which includes at least one insert for reducing wear on said annular bearing rib body 34 that has a downwardly facing exposed surface that is substantially flush with the surface of the upper wall of the bearing rib body.
  10. The plastic bobbin basket of claim 6 in which includes a plurality of inserts for reducing wear on said annular bearing rib body 34 is spaced around the extent of the bearing rib, with exposed surfaces of adjacent inserts being located alternately at the upper and lower surfaces of the bearing rib 34, and other exposed surfaces of the inserts facing outwardly at the surface of the outer wall of the bearing rib body.
  11. The bobbin basket of any preceding claim in which the portion of said flange 28 that forms said first, downstream side wall 30a of the rotation-restraining notch 32 includes means for reducing wear on said flange portion 28 caused by contact with the bobbin thread as it exits from the bobbin spool,
    • the area occupied by said means for reducing wear on said first side wall falling in the range from a small fraction of the potential area of wear at that location to the entire area of potential wear at that location.
  12. The bobbin basket of claim 11, in which:
    • (a) said means for reducing wear on the portion of said flange that forms said first, downstream side wall of said rotation-restraining notch comprises at least one insert embedded securely within said flange, and
    • (b) said means 70 for minimising damage to the second, upstream side wall of the rotation-restraining notch comprises a member secured to said second side wall.
  13. The plastic bobbin basket of any preceding claim in which at least one portion of the exterior surface of each of said wear-reducing means is exposed to contact with a curved, elongated area of the needle thread loop or rotary loop taker raceway with which it is associated, each of said exposed surface portions being smooth and free of sharp edges, the lengthwise radius of curvature of each of said exposed surface portions being not substantially greater than the radius of curvature of the immediately surrounding surface of the bobbin basket element with which it is associated.
  14. The bobbin basket of claim 11 or claim 12 in which said means for reducing wear on said flange portion caused by contact with the bobbin thread as it exits from the bobbin spool has at least one portion of its exterior surface exposed to contact with a curved, elongated area of the bobbin thread with which it associated, each of said exposed surface portions being smooth and free of sharp edges, the lengthwise radius of curvature of the immediately surrounding surface of the flange that forms said first, downstream side wall of the rotation-restraining notch being not substantially greater than the radius of curvature of the surrounding surface of the bobbin basket.
Anspruch[fr]
  1. Panier de canette 20 destiné à être utilisé avec un capteur de boucle rotatif dans une machine à coudre réalisant des points noués, qui comprend :
    • une paroi cylindrique 22, un élément de support cruciforme 24 prévu pour la paroi latérale cylindrique 22 et s'étendant en travers du fond du panier de canette, un montant 26 de support de la bobine de canette s'étendant axialement à partir dudit élément de support cruciforme 24 dans l'espace défini par ladite paroi latérale cylindrique 22,
    • une bride 28 s'étendent radialement vers l'extérieur à partir de la partie supérieure de ladite paroi latérale cylindrique, deux parties 28a, 28b de ladite bride formant des première et seconde parois latérales 30a, 30b, qui sont situées en vis-à-vis l'une de l'autre et sont positionnées d'une manière générale radialement de manière à former une encoche de limitation de rotation 32 dans la surface supérieure de la bride 28, ladite première paroi latérale 30a de l'encoche formant le côté aval de l'encoche de limitation de rotation 32 par rapport au sens de rotation du capteur de boucle rotatif, avec lequel le panier de canette est destiné à être utilisé, ladite seconde paroi latérale 30b de l'encoche formant le côté amont de ladite encoche de limitation de rotation 32 par rapport audit sens de rotation, ladite encoche 32 étant adaptée de manière à loger la partie formant ergot d'un doigt de positionnement fixe avec un ajustement fixe, mais suffisamment lâche pour permettre un mouvement de rotation limité en va-et-vient du panier de canette 20, et
    • une nervure de support annulaire 34 s'étendant radialement vers l'extérieur à partir de ladite paroi latérale cylindrique 22, ladite nervure 34 étant située entre la bride 28 mentionnée précédemment, qui s'étend vers l'extérieur, et la partie inférieure du panier de canette 20 et s'étendant essentiellement sur la périphérie du panier de canette 20 hormis sur une faible partie de ladite nervure annulaire 34, qui est supprimée de manière à former deux parties d'extrémité de nervure 38, 40, situées en vis-à-vis l'une de l'autre et qui définissent une zone de saisie et de libération du fil d'aiguille,
    • la première desdites parties d'extrémité de nervure 38 situées en vis-à-vis l'une de l'autre formant une encoche de saisie 42 sur l'extrémité aval, par rapport au sens de rotation mentionné précédemment du capteur de boucle rotatif avec lequel le panier de canette est adapté pour être utilisé, de la zone de saisie et de libération du fil d'aiguille, et
    • la seconde desdites parties d'extrémité de nervure 40 situées en vis-à-vis l'une de l'autre, étant situées au voisinage de ladite encoche de limitation de rotation 32 de manière à former une butée 44 pour le fil d'aiguille sur l'extrémité amont, par rapport au sens de rotation, de la zone de saisie et de libération d'une aiguille, et
       caractérisé en ce que :
    • (a) le panier de canette 20, qui inclut ladite paroi latérale cylindrique 22, ladite bride 28 qui s'étend vers l'extérieur et ladite nervure de support 34 qui s'étend vers l'extérieur, est réalisé d'un seul tenant en matière plastique, et
    • (b) ladite nervure de support 34 comprend des moyens 44 pour réduire l'usure sur ladite seconde partie d'extrémité de nervure amont, qui forme la butée d'aiguille mentionnée précédemment, et lorsque la boucle du fil d'aiguille vient en contact avec ladite butée, le fil est tiré à force en travers de la butée de manière à serrer la boucle autour du fil de la canette,
    • (c) ladite nervure de support 34 comprend des moyens pour réduire l'usure sur lesdites premières parties d'extrémité de nervure aval, qui forment l'encoche de saisie mentionnée précédemment, lorsque la boucle du fil d'aiguille est saisie dans ladite encoche et se déplace axialement en travers de l'encoche lorsque le capteur de boucle rotatif tourne et élargit la boucle,
    • (d) ladite seconde paroi latérale amont 30b de l'encoche de limitation de rotation comprend des moyens 70 pour réduire l'endommagement par impact appliqué à ladite seconde paroi latérale 30b par la partie formant ergot mentionné précédemment du doigt de positionnement fixe lorsque le panier de canette 20 est déplacé selon un mouvement d'oscillation en va-et-vient par la boucle du fil d'aiguille de manière à amener ladite seconde paroi latérale 30b à frapper ledit ergot de façon répétée lorsqu'une tension est appliquée au fil de la boucle du fil d'aiguille, tout d'abord dans un sens, puis dans l'autre,
    • (e) ladite de support 34 comporte des moyens pour réduire l'usure appliquée au corps de la nervure par la piste de circulation du capteur de boucle rotatif, sur laquelle la nervure est tourillonnée, alors que simultanément un contact substantiel est maintenu entre la piste et le corps de la nervure, y compris lesdits moyens de réduction d'usure, et
    • (f) la zone occupée par chacun desdits moyens pour réduire l'usure ou réduire l'endommagement par impact en un emplacement donné du panier de canette se situe dans une gamme comprise entre une faible fraction de la surface potentielle d'usure ou d'endommagement par impact en cet emplacement donné et l'ensemble de la zone d'usure potentielle ou d'endommagement potentiel en cet emplacement.
  2. Panier de canette 20 en matière plastique selon la revendication 1, dans lequel :
    • (a) lesdits moyens 44 pour réduire l'usure sur lesdites parties d'extrémité de nervure amont et aval et sur ledit corps de nervure comprennent au moins un insert enchâssé de façon fixe avec l'élément du panier de canette, auquel il est associé,
    • (b) lesdits moyens 70 pour réduire l'endommagement par impact de la seconde paroi latérale amont de l'encoche de limitation de rotation 32 comprennent un élément fixé à ladite seconde paroi latérale 30b.
  3. Panier de canette en matière plastique selon la revendication 2, dans lequel :
    • (a) au moins une partie de la surface extérieure de chacun des inserts de réduction d'usure 44 est exposé à un contact avec une surface allongée courbe de la boucle du fil d'aiguille ou de la piste du capteur de boucle rotatif, à laquelle elle est associée, chacun desdits éléments de surface exposée étant lisse et exempt d'arêtes vives, le rayon de courbure, dans le sens de la longueur, de chacun desdits éléments de surface exposée n'étant pas nettement supérieur au rayon de courbure de la surface directement environnante de l'élément du panier de canette auquel l'élément de surface est associé, et
    • (b) au moins une partie de la surface extérieure dudit élément 70 réduisant un endommagement par impact est exposé à un impact produit par la partie formant ergot dudit doigt de positionnement fixe.
  4. Panier de canette en matière plastique selon la revendication 3, dans lequel :
    • (a) la portion radialement extérieure de ladite partie d'extrémité de nervure aval 38 s'étend circonférentiellement de manière à former, avec la paroi latérale 22 du panier de canette 20, une encoche de saisie pour la boucle du fil d'aiguille, ladite encoche possédant une forme en "V" dans un plan perpendiculaire à l'axe de rotation du capteur de boucle rotatif associé, et
    • (b) un insert pour réduire l'usure est enchâssé en partie dans la paroi latérale 22 du panier de canette et en partie dans la partie d'extrémité de nervure 38, au voisinage de la partie inférieure de ladite encoche en forme de "V".
  5. Panier de canette en matière plastique selon la revendication 4, dans lequel :
    • (a) ladite partie d'extrémité de nervure aval 38, qui s'étend circonférentiellement, possède une forme qui se rétrécit légèrement vers l'intérieur au voisinage de l'extrémité du côté inférieur dans la nervure de support 34, et
    • (b) un second insert pour réduire l'usure est enchâssé en partie dans la paroi latérale 22 du panier de canette et en partie dans la partie d'extrémité de la nervure 38, au voisinage du début de ladite portion de forme rétrécie d'une partie d'extrémité de nervure.
  6. Panier de canette en matière plastique selon la revendication 3, 4 ou 5, qui inclut une pluralité d'inserts pour réduire l'usure, enchâssés dans le corps de la nervure annulaire de support 34.
  7. Panier de canette en matière plastique selon la revendication 6, qui comporte au moins un insert pour réduire l'usure sur ledit corps de la nervure annulaire, qui possède une surface exposée tournée vers l'extérieur, qui est essentiellement alignée avec la surface de la paroi extérieure du corps 34 de la nervure de support.
  8. Panier de canette en matière plastique selon la revendication 6, qui comprend au moins un corps de nervure de support annulaire 34, qui possède une surface exposée tournée vers le haut et qui est essentiellement de niveau avec la surface de la paroi supérieure du corps de la nervure de support.
  9. Panier de canette en matière plastique selon la revendication 6, qui comprend au moins un insert servant à réduire l'usure appliquée audit corps de nervure de support annulaire 34 qui possède une surface exposée tournée vers le bas, qui est essentiellement alignée avec la surface de la paroi de support du corps de la nervure de support.
  10. Panier de canette en matière plastique selon la revendication 6, qui inclut une pluralité d'inserts pour réduire l'usure sur ledit corps de nervure de support annulaire 34, qui sont espacés sur l'étendue de la nervure de support, des surfaces exposées d'inserts adjacents étant situées alternativement sur les surfaces supérieure et inférieure de la nervure de support 34, et d'autres surfaces exposées des inserts étant tournées vers l'extérieur au niveau de la surface de la paroi extérieure du corps de la nervure de support.
  11. Panier de canette selon l'une quelconque des revendications précédentes, dans lequel la partie de ladite bride 28 qui forme ladite première paroi latérale aval 30a de l'encoche de limitation de rotation 32 comprend des moyens pour réduire l'usure sur ladite partie formant bride 28 provoquée par le contact avec le fil de la canette lorsqu'il sort de la bobine de la canette,
    • la surface occupée par lesdits moyens servant à réduire l'usure sur ladite première paroi latérale se situant dans la gamme comprise entre une faible fraction de la surface potentielle d'usure en cet emplacement et la surface complète d'usure potentielle en cet emplacement.
  12. Panier de canette selon la revendication 11, dans lequel :
    • (a) les moyens pour réduire l'usure sur la partie de ladite bride, qui constitue ladite première paroi latérale aval de ladite encoche de limitation de rotation comprennent au moins un insert enchâssé de façon fixe dans ladite bride, et
    • (b) lesdits moyens 70 pour réduire l'endommagement de la seconde paroi latérale amont de l'encoche de limitation de la rotation comprennent un élément fixé à ladite seconde paroi latérale.
  13. Panier de canette en matière plastique selon l'une quelconque des revendications précédentes, dans lequel au moins une partie de la partie extérieure de chacun desdits moyens de réduction de l'usure est exposée à un contact avec une zone courbée allongée de la boucle du fil d'aiguille ou de la piste du capteur de boucle rotatif, à laquelle sont associées chacune desdites parties de surface exposée étant lisses et exemptes d'arêtes vives, le rayon de courbure, dans le sens longitudinal, de chacune desdites parties de surface exposée n'étant pas nettement supérieur au rayon de courbure de la surface directement environnante de l'élément du panier de canette, auquel ces parties de surfaces sont associées.
  14. Panier de canette selon la revendication 11 ou la revendication 12, dans lequel lesdits moyens pour réduire l'usure produite sur ladite partie formant bride par un contact avec le fil de canette lorsqu'il sort de la bobine de canette, comportent au moins une partie de leur surface extérieure exposée de manière à venir en contact avec une zone courbe et allongée du fil de la canette, à laquelle cette surface est associée, chacune desdites parties de surface exposées étant lisse et exempte d'arêtes vives, le rayon de courbure, dans le sens longitudinal, de la surface directement environnante de la bride, qui forme ladite première paroi latérale aval de l'encoche de limitation de la rotation, n'étant pas nettement supérieur au rayon de courbure de la surface environnante du panier de canette.






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