This invention concerns a unit to bear coaxial spindles, as set forth
in the main claim. The unit to bear coaxial spindles according to this invention
is applied advantageously to the textile industry and especially to spinning machines,
twisters and two-for-one twisters.
Spindles on textile machines of the state of the art have a rotary
shaft and are borne on bolsters with roller bearings or ball bearings.
The spindles are fitted above the spindle-bearing frames and are
rotated at a speed of about 15,000 r.p.m. or more. The spindles are generally rotated
by a belt which runs in the air.
There may be the situation of a plurality of spindles installed on
the same spindle-bearing frame and cooperating with the same belt driven by one
single motor or the situation of a shaft bearing a plurality of pulleys, each of
which actuates a belt that actuates a spindle.
The spindle-bearing systems of the state of the art entail the problem
of being unable to ensure that at least two spindles rotate at the same speed,
for this same speed of rotation is necessary to achieve an excellent doubling of
two yarns, for instance.
In fact, the spindles nowadays either are set in rotation individually
by different motors or are driven by the same motor, to which they are connected
by a belt, but neither of these two methods ensures a good synchronized rotation
of two spindles.
Moreover, with the spindle-bearing systems of the state of the art
the spindles are arranged on only one side, generally the upper side, of the machine,
and this situation involves a great overall bulk of the machine owing to the great
number of spindles fitted to a machine.
Furthermore, the spindle-bearing systems of the state of the art
entail the drawback that owing to the high speed of rotation of the spindles the
transmission belt vibrates in the air and generates unpleasant vibrations and noises.
These vibrations and noises are greater when one belt drives a plurality
So as to obviate this noise, proposals have been made that the transmission
belt should be eliminated and that each spindle should be driven by a high-frequency
motor positioned also on the same axis as the spindle.
This system, however, increases the cost of the machine considerably
and makes it uncompetitive on the market precisely owing to the necessity, determined
by the state of the art, of having to use a high-frequency motor so as to be able
to bring the spindles to the desired speed.
The present applicants have designed, tested and embodied this invention
to overcome the shortcomings of the state of the art and to achieve further advantages.
This invention is set forth and characterized in the main claim,
while the dependent claims describe variants of the main embodiment.
The purpose of the invention is to provide a unit to bear spindles
which is suitable to hold two coaxial spindles.
This unit can be fitted to spinning machines, twisters and two-for-one
The unit according to the invention enables the spindles to be driven
two by two and a perfectly synchronized rotation of at least one pair of spindles
to be ensured.
A secondary purpose of the invention is to eliminate the problems
of vibration and noise generated by the high speed of rotation of the spindles
and by the linear speed of the belt.
The unit to bear coaxial spindles according to the invention enables
the spindles to be fitted coaxially, two by two, on the two opposite, upper and
lower, sides of the spindle-bearing frame.
In the unit to bear coaxial spindles according to the invention the
plurality of rotary shafts cooperates with a tangential drawing belt, which transmits
to the shafts the rotary motion needed for the winding of the yarn.
According to a variant each rotary shaft bearing coaxially a pair
of spindles is individually powered so as to form a complete, independent assembly
consisting of a motor and of a unit to bear coaxial spindles.
The unit to bear coaxial spindles according to the invention is positioned
advantageously on a frame having a closed box-like structure, within which there
runs the transmission belt that sets the coaxial spindles in rotation.
The spindles on the spindle-bearing frame are fitted in relation
to the two opposite faces by employing two opposed holders, each of which holds
A pulley is installed on the shaft of the spindle between the two
holders and is rotated by a drawing belt.
According to a variant the spindle-bearing frame includes double
spindle holders and lodges two substantially coaxial but separate spindles, for
instance for the operations of doubling the yarns. In this case each spindle receives
its rotary motion from its own transmission belt.
The transmission belts gets their motion either from one single motor
or from two separate motors.
According to another variant, where old machines are being modernised,
the invention arranges that there is generally a tangential belt to perform the
drawing operation, as was the case previously, the purpose being to simplify and
make more economical the modernising work.
According to a further variant the spindles may be bored axially
to enable an elastomeric yarn or another similar yarn to pass through and be wound
in a spiral about the yarn being processed.
According to the invention one side of the spindle-bearing frame
can be dismantled to facilitate entry to the inside.
According to the invention the spindle-bearing frame can be further
soundproofed by applying or spraying within it a sound-deadening material.
According to a variant each spindle can be driven individually by
a normal two-pole, four-pole or multi-pole electric motor governed by an actuator
inverter for adjustment of the speed.
This is made possible by acting on the ratios between the pulley
positioned coaxial with, and firmly secured to, the spindle and the pulley located
on the shaft of the motor.
The invention, by providing opposed spindles, enables the machine
to be better balanced and also makes possible two differentiated take-up packages.
It is also possible to carry out the doubling of two yarns coming
from two coaxial opposed spindles rotating in perfect synchronization; the result
of such doubling is excellent inasmuch as the two spindles are coaxial and firmly
connected together and therefore rotate at the same speed.
The doubling can be carried out in the same way with three or four
yarns coming from different spindles.
According to the invention , where the tubes are vertical, the falling
of the tube fitted to the lower side is prevented by using tubes with a known system
of axial attachment.
The falling of the coils of yarn into the lower tube is obviated,
instead, by employing a coil-retaining device which is applied axially about the
spindle and cooperates with the outer surface of the spindle so as to prevent the
outermost coils becoming unwound by themselves.
The attached figures are given as a non-restrictive example and show
some preferred embodiments of the invention as follows:-
- shows a lengthwise section of a spindle-bearing frame according to the invention;
- shows a cross-section of the spindle-bearing frame along the line A-A of Fig.1;
- shows a lengthwise section of a variant of the spindle-bearing frame according
to the invention;
- shows a further type of embodiment according to the invention;
- to 7 show some diagrams of the doubling of a plurality of yarns coming from
spindles fitted to a spindle-bearing frame according to the invention;
- Figs.8 and 9
- show a plan view of two different types of a coil-retaining device;
- is a front view of a spindle to which is fitted a coil-retaining device of
the type of Fig.8.
The reference number 10 in the attached figures denotes generally
a spindle-bearing frame to which is fitted a plurality of units 36 bearing coaxial
spindles according to the invention.
The spindle-bearing frame 10 according to the invention comprises
in this case a metallic support 11 with a U-shaped section closed by a lateral
plate 12 so as to form a closed box-shaped structure.
A plurality of equidistant holes 14 in which holders 15 bearing the
spindles 16 are fitted is included on the upper 13a and lower 13b sides of the
U-shaped metallic support 11.
On each of the holders 15 of the spindles 16 is installed a bearing
30 secured to the spindle-bearing frame 10 by a flange 17, which holds a bearing
30 and is secured by screws 18 in this case.
In this case a rotary shaft 19, in the middle of which a first pulley
20a is installed coaxially and solidly, passes through the holders 15 of the spindles
A tangential drawing belt 21 cooperates with the first pulley 20a,
runs within the spindle-bearing frame 10 and is driven in turn by a second pulley
20b solidly fixed coaxially to a drive shaft of a motor 22.
According to a variant (Fig.3) two intermediate plates 23 separated
by a spacer 31 are included in the U-shaped metallic support 111 of the spindle-bearing
frame 110; each of these intermediate plates 23 holds a further bearing 130 coinciding
with the holes 14.
In this way each holder 115 of the spindles 116 is installed on two
bearings 30-130; two transmission belts 122 are included and are driven by one
and the same motor 122.
In this case each spindle 116 is hollow and each spindle holder 115
contains an axial bore consisting of an inner first conduit 32 that passes axially
through the spindle 116 and the holder 115.
The spacer 31 includes on each face in contact with the intermediate
plates 23 a radial second conduit 33 joined at one side to an axial third conduit
34 and extending in a fourth conduit 35.
With the embodiment of this variant the invention enables the yarn
to be covered by means of a elastomeric yarn or the like.
According to another variant soundproofing material is applied to
the inner side of the U-shaped support 11 so as to soundproof the spindle-bearing
frame 10 additionally.
The embodiment shown in Fig.4 is used where a conventional machine
is being modernised, and comprises a common spindle-bearing plate 210 with a support
11 to which the holders 115 of the spindles are generally applied by being screwed.
The drawing of the rotary shaft 19, to which are applied the two
holders 115 coaxial with and opposite to the support 11, is generally carried out
by a tangential belt 21, which runs in air, by means of an interposed pulley 20a.
In this case a conventional spindle-bearing plate 210 is equipped
with a second lower holder 115a of a spindle by applying to the rotary shaft 19
a bolster 37 with a relative flange 38, to which the holder 115a of the spindle
is screwed. The bolster 37 bears a roller bearing or ball bearing 130.
This embodiment simplifies greatly the work to modernise conventional
spindle plates 210 and makes them suitable to bear spindle-bearing units, each
of which holds two coaxial spindles
By means of the spindle-bearing frame 10 according to the invention
(Fig.5) it is possible to obtain two differentiated take-up packages 24 at the
same time, each package coming from a different spindle 16.
With the spindle-bearing frame 10 according to the invention it is
possible to carry out twisting of two yarns 25 coming from two spindles 16 installed
on the same rotary shaft 19 (Fig.6) or even the twisting of three or more yarns
The problem of the falling of the spindle 16 fitted to the lower
side in the spindle-bearing frame 10 according to the invention is overcome by
using tubes with an axial attachment of a known type.
Instead, the problem of the falling of coils of yarn is overcome
by using an appropriate coil-retaining device 26, which is applied axially around
the spindle 16 and cooperates with the outer surface thereof, thus preventing
the outermost coils unwinding by themselves (Fig.10).
In the example of Fig.8 the coil-retaining device 26 comprises an
outer plastic ring 27 bearing a plurality of foldable threads 28 arranged radially
within the ring 27. When the coil-retaining device 26 has been applied axially
to the spindle 16, the foldable threads 28 cooperate with the outer surface of
the spindle 16 and bend, thus retaining the outermost coils resiliently.
In the form of embodiment of Fig.9 the radial foldable threads 28
have been replaced by a plurality of plastic threads 29 connected at their two
ends to the plastic ring 27 so as to define between them a space for the axial
passage of the spindle 16.
In the spindle-bearing frame 10 according to the invention the units
36 to bear spindles can be powered one by one by using a plurality of two-pole
or multi-pole motors and by installing an inverter to adjust their speed. This
is possible inasmuch as the pulleys can be dimensioned as desired.