BACKGROUND OF THE INVENTION
This invention generally relates to elevator support systems.
More particularly, this invention relates to a device for securing an end of a load
bearing arrangement in an elevator system.
Elevator systems typically include some form of load bearing
member, such as roping or a belt for supporting and moving the cab through the hoistway
as desired. In some situations, the belt couples a counterweight to the cab.
Regardless of the specific configuration of the elevator
system, it typically is necessary to secure ends of the belt to an appropriate structure
within the elevator system. A variety of configurations of assemblies for securing
the ends of a belt in an elevator system have been used. One example includes a
cast socket and wedge arrangement where a portion of the belt is secured between
the socket and wedge. One drawback associated with currently used arrangements is
that the casting process is relatively expensive.
Not only is a casting process often expensive, but it limits
the ability to maximize the design of the belt-engaging surfaces within the socket.
Because a cast socket has inside surfaces that are not easily accessible, it is
often difficult to treat the belt-engaging surfaces in a manner to enhance the gripping
characteristics of the assembly once the socket is formed. Forming grooves on the
inner socket surfaces during the casting process is often considered too expensive.
Another shortcoming of current systems is that the casting
process is not accurate enough to provide the dimensional tolerances needed for
many situations. One particular issue is presented by the need to establish and
maintain a parallel alignment between opposite sides of the socket and opposite
sides of the wedge. Without a truly parallel alignment, the forces on the load bearing
member are not evenly distributed and belt life is compromised. Current designs
and manufacturing approaches do not permit consistent alignment of the socket and
wedge surfaces that engage the load bearing member.
There is a need for an improved elevator load bearing termination
arrangement. This invention addresses that need and overcomes the shortcomings described
SUMMARY OF THE INVENTION
In general terms, this invention is a device for securing
an end of a load bearing member such as a belt in an elevator system. The device
includes a socket and a wedge that is received within the socket. The socket also
supports at least one insert that is received between the socket and the wedge to
engage a side of the load bearing member. The insert preferably includes a contoured
surface on the side that is received against the socket, which cooperates with a
corresponding contour on the socket. The contoured surface preferably is at least
partially rounded to permit the position of the insert to be adjusted within the
socket to ensure a desired alignment of belt-engaging surfaces on both sides of
The insert preferably includes an engaging surface on the
side of the insert that faces toward the belt. In one example, the engaging surface
includes grooves for better frictional engagement with the belt.
This invention includes using an insert on each side of
the wedge within the socket. Because the inserts are made as separate parts from
the socket, including an engaging surface on the belt engaging side is easy to accomplish.
The various features and advantages of this invention will
become apparent to those skilled in the art from the following detailed description
of the currently preferred embodiment. The drawings that accompany the detailed
description can be briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
- Figure 1 diagrammatically illustrates a device designed according to this invention.
- Figure 2 is a side view of the embodiment of Figure 1.
- Figure 3 is a cross sectional view along the line 3-3 in Figure 2.
- Figure 4 shows selected features of a portion of the embodiment of Figure 1.
- Figure 5 schematically shows a selective feature of the example socket of Figures
1 through 3.
- Figure 6 is a cross sectional illustration taken along the lines 6-6 in Figure
A device 20 for handling an end of a load bearing member
30 in an elevator system includes a socket 22. In the illustrated example, two socket
portions 24 and 26 cooperate with each other and a wedge 28 to secure the end of
the load bearing member 30 into a desired position. A two-piece socket has advantages
in simplifying the manufacture of the socket. A one-piece socket is also within
the scope of this invention.
As can be appreciated from the drawings, the socket portions
24 and 26 in the illustrated example include a generally u-shaped, channel configuration.
The open end of each channel is placed against the open end of the other and the
two portions are secured together. The illustrated example includes a dovetail arrangement
including a receiver 32 on the second socket portion 26 that receives a dovetail
34, which is on the first socket portion 24. The two socket portions preferably
are secured together using welding, which is illustrated at 36 in Figure 3. Alternative
arrangements for securing the socket portions together in embodiments where a two-piece
socket is used are possible. Those skilled in the art who have the benefit of this
description will be able to select the appropriate geometries and connecting methods
to meet the needs of their particular situation.
The load bearing member 30 in the illustrated example is
a coated steel belt. This invention is not limited, however, to coated steel belts.
Rather, any load bearing member within an elevator system that can be accommodated
using a socket and wedge arrangement designed according to this invention may be
used. The term "belt" as used in this description should not be construed in its
strictest sense. It should be considered synonymous with roping or load bearing
The currently preferred arrangement includes two inserts
40 and 42 that are received within the socket 22. In the illustrated example, the
insert 40 is associated with the socket portion 24 while the insert 42 is associated
with the socket portion 26. The inserts preferably include an outer contour 46 that
cooperates with a correspondingly contoured inner surface 48 on the socket. The
contour of the surface 46 preferably is at least partially rounded to permit adjustment
of the insert 42 relative to the socket 22. Having adjustably positionable inserts
40 and 42 allows the belt engaging surfaces 50 and 52 to be aligned as desired to
most evenly distribute pressure on the belt 30.
The illustrated example includes contoured surfaces on
the inserts 40 and 42 and the socket portions 24 and 26, which have a varying radius
along at least a portion of the cooperating surfaces. The radii are chosen to accommodate
the belt and socket dimensions of a particular embodiment and can be varied as necessary.
Given this description, those skilled in the art will be able to determine the appropriate
dimensional relationships that will best suit their particular situation.
The illustrated example includes a generally concave surface
on the socket and a generally convex surface on the inserts. The orientation of
the cooperating contoured surfaces can best be appreciated from Figure 3.
The overall size of the inserts 40 and 42 allows for movement
of the inserts within the socket so that the automatic adjustment of the belt engaging
surfaces 50 and 52 is possible. Accordingly, there is some clearance shown at 60
and 62 between edges of the insert portions and the interior of the socket. Such
clearance permits the insert portions to move relative to the socket into a position
where the belt engaging surfaces are aligned as desired.
At least one insert preferably is used to provide adjustment
of the belt engaging surfaces of the assembly 20. With at least one insert member,
any variation in surface alignment of an oppositely facing socket surface can be
compensated as the insert moves into a desired position to most evenly distribute
the pressure on the belt 30. The alignment preferably occurs automatically as a
result of forces on the assembly caused by the weight of the system components.
Having two inserts maximizes the ability to achieve evenly
distributed forces. Utilizing two insert members provides the further advantage
of having a friction-enhancing or transversely grooved belt-engaging surface on
each side, which does not require complex manufacturing as is necessary when an
interior surface on a socket is grooved. Any known machining technique can provide
the grooves 53 or knurling on the belt engaging surfaces 50 and 52 of the inserts.
As schematically shown in Figure 4, the grooves preferably extend in a direction
perpendicular to the length of the belt 30.
The inserts 40 and 42 can be made using a variety of materials.
The example of the illustrations includes sintered steel inserts. The inserts can
be cast, formed or machined in a known manner. Other metals or suitably hard synthetic
materials may be used. Given this description, those skilled in the art will be
able to choose from among commercially available materials and a correspondingly
appropriate method of forming the inserts to meet the needs of their particular
situation. For example, the friction-enhancing surface characteristics may be formed
onto the inserts during the process of making the inserts or may be machined onto
the insert surfaces after the inserts have been formed.
In one example, the belt engaging surfaces 50 and 52 on
the inserts preferably are aligned to be exactly parallel. The rounded, cooperating
contours (i.e., the surfaces 46 and 48) permit self-alignment of the inserts. The
belt engaging surfaces 50 and 52 preferably have a surface that is friction-enhancing
(i.e., includes grooves 53) to better secure the belt 30 within the assembly 20.
The belt engaging surface 54 on the wedge 28 preferably has grooves or another friction-enhancing
surface for the same purpose.
The socket 22 is designed to allow for placing the inserts
40 and 42 into the socket in combination with the wedge 28 to secure the belt 30
in place. In one example, the two socket portions are welded together. Sheet metal
is a preferred material for the socket to accommodate welding.
The illustrated example includes a feature that facilitates
maintaining the inserts within the socket during the belt placement procedure. As
best appreciated from Figures 5 and 6, the socket preferably includes openings 70
and 72 on opposite sides. The insert 40 includes a boss 74 that extends at least
partially into the opening 70 on the socket portion 24. A recess 76 preferably extends
through a center of the boss 74 toward the interior of the insert 40.
A stem portion 78 of a holding member 79 preferably is
at least partially received within the recess 76. The stem 80 preferably includes
a plurality of ribs 78 that facilitate maintaining the holding member 79 in place
on the insert 40.
The holding member 79 preferably includes a flange portion
82 that has an outside dimension that is greater than the size of the opening 70
so that at least a portion of the holding member 79 remains outside of the socket
Similarly, a holding member 84 facilitates holding the
insert 46 in place while positioning and securing the belt 30 within the assembly.
The insert 46 includes a boss 86 having an opening 88. A stem 90 on the holding
member 84 preferably includes flexible ribs 92 that facilitate maintaining the holding
member 84 in place. A flange portion 94 on the holding member 84 preferably extends
outside the opening 72 on the socket portion 26.
The holding members 79 and 84 preferably are made from
a plastic material and are put into the position illustrated in Figure 6 to prevent
the inserts 40 and 42 from sliding out of the socket during assembly. The bosses
74 and 86 and the openings 70 and 72 preferably are dimensioned so that the use
of the holding members 79 and 84 do not later interfere with the automatic adjusting
feature of the inventive assembly as described above. The openings 70 and 72 preferably
are dimensioned large enough to provide clearance between the opening and the respective
bosses so that the movement of the inserts 40 and 42 is not restricted and that
a desired alignment of the belt engaging surfaces remains possible.
A conventional belt termination clip 66 preferably is provided
near the terminal end of the belt 30 as a further safeguard against slippage. A
conventional connecting member 68 facilitates connecting the assembly 20 to another
portion of the elevator system.
The preceding description is exemplary rather than limiting
in nature. Variations and modifications to the disclosed embodiment may become apparent
to those skilled in the art that do not necessarily depart from the essence of this
invention. The scope of legal protection given to this invention can only be determined
by studying the following claims.