Patent Publication Number: US-6662408-B2

Title: Elevator load bearing termination assembly with gripping inserts

Description:
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 above. 
     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 belt. 
     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 
     FIG. 1 diagrammatically illustrates a device designed according to this invention. 
     FIG. 2 is a side view of the embodiment of FIG.  1 . 
     FIG. 3 is a cross sectional view along the line  3 — 3  in FIG.  2 . 
     FIG. 4 shows selected features of a portion of the embodiment of FIG.  1 . 
     FIG. 5 schematically shows a selective feature of the example socket of FIGS. 1 through 3. 
     FIG. 6 is a cross sectional illustration taken along the lines  6 — 6  in FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     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 FIG.  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 member. 
     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 FIG.  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 FIG. 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 FIGS. 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  22 . 
     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 FIG. 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.