METHOD OF MAKING A LOAD BEARING MEMBER FOR AN ELEVATOR SYSTEM
An exemplary load bearing member for use in an elevator system is made by a process that includes heating at least one tension member. The heated tension member is placed adjacent one side of a first jacket layer. The first jacket layer is at least partially melted in the vicinity of the heated tension member such that the tension member at least partially penetrates the first jacket layer. Subsequently, a second jacket layer is added adjacent to the one side of the first jacket layer such that the elongated tension member is between the first and second jacket layers. The second jacket layer is at least partially melted in the vicinity of the heated tension member such that the tension member at least partially penetrates the second jacket layer. The first and second jacket layers are secured together such that the resulting load bearing member has a planar traction.
This application is a divisional application of U.S. patent application Ser. No. 12/066,389 filed Mar. 11, 2008.
FIELD OF THE INVENTIONThis invention generally relates to elevator systems. More particularly, this invention relates to a load bearing member for elevator systems.
DESCRIPTION OF THE RELATED ARTThere are several known types of elevator systems. Traction-based systems typically include an elevator car, a counterweight and load bearing members that support the car and counterweight. The car moves between different levels because of traction between the load bearing members and a traction sheave, for example.
Elevator system load bearing members come in various forms. For many years steel ropes were used. More recently, other load bearing members have been introduced. Some examples include flat belts having a plurality of tension members encased in a urethane jacket. Some examples include steel cords as the tension members while others include aramid materials as the tension members.
Regardless of the selected materials, known manufacturing methods typically result in a plurality of grooves in at least one exterior surface of the jacket. These grooves result from known manufacturing processes.
One difficulty associated with such grooves is that they tend to introduce noise and vibration during elevator system operation as the grooves contact the traction sheave, for example. Various arrangements have been proposed for minimizing the vibration and noise-generating effects of such grooves.
It would be beneficial to be able to eliminate the grooves entirely. This invention addresses that need.
SUMMARY OF THE INVENTIONNom An exemplary load bearing member for use in an elevator system is made by a process that includes heating at least one tension member. The heated tension member is placed adjacent one side of a first jacket layer. The first jacket layer is at least partially melted in the vicinity of the heated tension member such that the tension member at least partially penetrates the first jacket layer. Subsequently, a second jacket layer is added adjacent to the one side of the first jacket layer such that the elongated tension member is between the first and second jacket layers. The second jacket layer is at least partially melted in the vicinity of the heated tension member such that the tension member at least partially penetrates the second jacket layer. The first and second jacket layers are secured together such that the resulting load bearing member has a planar traction.
The various features and advantages of this invention will become apparent to those skilled in the art from the following description of a currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.
The illustrated example is a flat belt. This invention is not limited to a particular geometry or configuration of the load bearing member 30.
One feature of the illustrated example is that an exterior surface 40 of the second layer 38 does not include any grooves. In other words, the exterior surface 40 is grooveless. This is different than known arrangements where grooves that are generally perpendicular to the length of the load bearing member 30 are spaced along at least one exterior surface of the jacket.
Similarly, an exterior surface 42 of the first layer 36 does not have any grooves.
In one example, one or both of the exterior surfaces 40 and 42 may be textured to provide a desired friction characteristic, for example. In general, a smooth, grooveless exterior surface provides sufficient traction characteristics and avoids noise generation that has been associated with load bearing members that include exterior grooves on a jacket.
As schematically shown in
The tension member 32 is provided from a supply 64 such as a reel, for example. In one example, a plurality of reels of steel cords are fed into the mold 52 along with the first layer 36. The first layer 36 is supported on the exterior surface 55 of the mold wheel 54 and the tension members 32 are supported on the first layer 36. This is schematically shown, for example, in
In the example of
In the example of
The load bearing member 30 exits the mold 52 and is finished in a known manner in a finishing station 76. One example includes a cooling bath for cooling the polymer materials of the jacket 34. Any surface texturing or dimensional controls can be accomplished in a known manner within the finishing station 76.
Utilizing a first layer 36 of a jacket to support at least one tension member 32 within a mold eliminates the need for using bridges associated with conventional molding techniques for supporting the tension member 32 within the mold. Eliminating such bridges eliminates the resulting grooves that are associated with conventional arrangements. Accordingly, the disclosed example provides the advantage of being able to have an exterior jacket 34 of a load bearing member 30 with grooveless exterior surfaces (facing opposite from each other in the case of a flat belt, for example). Having a grooveless exterior surface eliminates a significant source of potential noise and vibration in an elevator system.
In one example, the materials selected for the first layer 36 and the second layer 38 are selected based upon friction characteristics of those materials. In one example, different materials are selected to have different friction characteristics for the exterior surfaces 40 and 42, respectively. In another example, at least one of the materials for at least one of the layers has a different color than the other. In still another example, at least one of the materials selected for at least one of the layers has a characteristic that facilitates visual inspection techniques that can be used for determining a condition of the load bearing member 30 within an elevator system.
The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples 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.
Claims
1. A load bearing member for use in an elevator system made by the process, comprising the steps of:
- (A) heating at least one elongated steel cord tension member that is configured to support a load of an elevator car in an elevator system;
- (B) placing the heated tension member adjacent one side of a first jacket layer that is against a substrate;
- (C) at least partially melting the first jacket layer in the vicinity of the heated tension member such that the tension member at least partially penetrates the first jacket layer;
- (D) subsequently adding a second jacket layer adjacent to at least the one side of the first jacket layer such that the elongated tension member is between the first and second jacket layers, wherein the second jacket layer is at least partially melted in the vicinity of the heated tension member such that the tension member at least partially penetrates the second jacket layer; and
- (E) securing the first and second jacket layers together such that the resulting load bearing member has a planar traction surface configured to contact a traction sheave in an elevator system.
2. The load bearing member of claim 1, wherein the first jacket layer has a first friction characteristic and the second jacket layer has a second, different friction characteristic.
3. The load bearing member of claim 1, wherein the first jacket layer is different than the second jacket layer urethane.
4. The load bearing member of claim 1, wherein the first jacket layer comprises a polymer and the second jacket layer comprises urethane.
5. The load bearing member of claim 4, wherein the polymer comprises urethane.
6. The load bearing member of claim 1, including using a plurality of tension members.
7. The load bearing member of claim 1, wherein step (D) includes extruding the second jacket layer onto the one side of the first jacket layer.
8. The load bearing member of claim 1, wherein step (E) includes using a temperature of at least one of the first or second jacket layers sufficient to cause at least partial melting of at least one of the layers to thereby bond the first and second layers together.
9. The load bearing member of claim 1, wherein step (B) includes using a preformed first jacket layer and supporting the tension member on the one side of the first jacket layer.
10. The load bearing member of claim 9, wherein step (B) includes supporting the preformed first jacket layer on a mold wheel with the one side facing away from an axis of rotation of the mold wheel.
Type: Application
Filed: Sep 23, 2011
Publication Date: Jan 19, 2012
Inventors: Hugh O'Donnell (Longmeadow, MA), Hubert E. Goeser (Dannenberg)
Application Number: 13/241,759
International Classification: B66B 7/06 (20060101); D02G 3/36 (20060101); B32B 37/14 (20060101);