BELT WITH GUIDE ELEMENTS

Description

BACKGROUND

[0001] Embodiments disclosed herein relate to elevator systems, and more particularly, to shape of a load bearing member for use in an elevator system and guidance of the load bearing member.

[0002] Elevator systems are useful for carrying passengers, cargo, or both, between various levels in a building. Some elevators are traction based and utilize load bearing members such as belts for supporting the elevator car and achieving the desired movement and positioning of the elevator car.

[0003] Where belts are used as a load bearing member, a plurality of tension elements are embedded in a common elastomer belt body. In an exemplary traction elevator system, a machine drives a traction sheave with which the belts, interact to drive the elevator car along a hoistway. Belts typically utilize tension members formed from steel elements, but alternatively may utilize tension members formed from other materials such as carbon fiber composites. Belts have been used in combination with a crowned traction sheave in many different system layouts and installations worldwide. The use of the crowned traction sheave ensures centering of the belt within the width of each groove of the traction sheave. However, the use of a crown on the traction sheave has several drawbacks such as uneven pressure distribution on the jacket as well as uneven load sharing by the cords inside the belt.

[0004] EP 1396458 A2 discloses a lift system with a drive transmission arrangement consisting of flat belts and pulleys. The flat belt is provided on at least one of its sides with longitudinal ribs.

[0005] EP 1886969 A1 discloses a load-bearing mechanism for a lift system with a drive side with two or three drive ribs and a deflecting side on the opposite side with a guide rib.

[0006] DE 20 2008 001786 U1 discloses a flat belt with round tension members embedded within a jacket material.

[0007] DE 10 2009 025954 A1 discloses a flat belt with grooves and transverse slots.BRIEF SUMMARY

[0008] In one embodiment, there is disclosed a belt for an elevator system as recited in claim 1.

[0009] In some embodiments a plurality of belt guide features are arrayed across a width of the belt.

[0010] In some embodiments the belt guide feature has a curvilinear cross-section.

[0011] In some embodiments the belt guide feature includes a plurality of belt guide feature segments separated along the belt length by a plurality of feature gaps.

[0012] In some embodiments the belt guide feature has a lower durometer than the traction surface.

[0013] In some embodiments the elevator system includes a hoistway, an elevator car located in the hoistway and movable along the hoistway, a traction sheave with flat traction surfaces and a belt as described above.

[0014] In some embodiments a biasing member is operably connected to the guide sheave to bias the guide sheave toward the belt.

[0015] In some embodiments a distance between the guide sheave and the traction sheave is in the range of 0.2 times and 2.0 times a traction sheave diameter.

[0016] In some embodiments a plurality of belts are arranged along a width of the flat traction sheave.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The subject matter is particularly pointed out and distinctly claimed at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: FIG. 1 is a perspective view of an example of a traction elevator system; FIG. 2 is a cross-sectional view of an embodiment of a belt for an elevator system; FIG. 3 is a cross-sectional view of an embodiment of a tension member for an elevator system; FIG. 4 is a cross-sectional view of another embodiment of a belt for an elevator system; FIG. 5 is a cross-sectional view of an arrangement described for reference purposes only of a belt for an elevator system; FIG. 6 is a cross-sectional view of an arrangement described for reference purposes only of a belt for an elevator system; FIG. 7 is an illustration of a traction sheave and guide sheave arrangement for an elevator system; FIG. 8 is an illustration of an elevator belt with discontinuous guide features; and FIG. 9 is an illustration of another elevator belt with discontinuous guide features.

[0018] The detailed description explains disclosed embodiments, together with advantages and features, by way of example with reference to the drawings.DETAILED DESCRIPTION

[0019] Referring now to FIG. 1, an exemplary embodiment of an elevator system 10 is illustrated. The elevator system 10 includes an elevator car 14 configured to move vertically upwardly and downwardly within a hoistway 12 along a plurality of car guide rails (not shown). Guide assemblies mounted to the top and bottom of the elevator car 14 are configured to engage the car guide rails to maintain proper alignment of the elevator car 14 as it moves within the hoistway 12.

[0020] The elevator system 10 also includes a counterweight 16 configured to move vertically upwardly and downwardly within the hoistway 12. The counterweight 16 moves in a direction generally opposite the movement of the elevator car 14 as is known in conventional elevator systems. Movement of the counterweight 16 is guided by counterweight guide rails (not shown) mounted within the hoistway 12. In the illustrated, non-limiting embodiment, at least one load bearing member, for example, a belt 18, coupled to both the elevator car 14 and the counterweight 16 cooperates with a traction sheave 20 mounted to a drive machine 22. To cooperate with the traction sheave 20, at least one belt 18 bends in a first direction about the traction sheave 20. Although the elevator system 10 illustrated and described herein has a 1:1 roping configuration, elevator systems 10 having other roping configurations such as 2:1 and hoistway layouts are within the scope of the present disclosure. The at least one belt 18 may also be routed over one or more other sheaves, for example, a deflector sheave 24 located between the traction sheave 20 and the elevator car 14. While not shown in the embodiment of FIG. 1, additional deflector sheaves 24 may be utilized in the elevator system 10 to direct the at least one belt 18 to selected positions in the hoistway 12. For example, additional deflector sheaves 24 may be located between the traction sheave 20 and the elevator car 14 and / or between the traction sheave 20 and the counterweight 16.

[0021] The elevator system 10 further includes one or more guide sheaves 26 configured to guide the belt 18, such that the belt 18 is positioned in a desired location along the deflector sheave 24 and / or the traction sheave 20. To prevent excessive wear of the belt 18 or to prevent inadvertent slippage of the belt 18, the desired location is at or about a lateral center of the traction sheave 20, as shown in FIG. 2. Referring again to FIG. 1, the belt 18 includes a traction surface 28 interactive with the traction sheave 20 to drive the elevator car 14 and / or the counterweight 16 of the elevator system 10. The traction surface 28 may additionally be interactive with the deflector sheaves 24. The belt 18 further includes a back surface 30 opposite the traction surface 28. The back surface 30 is interactive with the guide sheaves 26 to guide positioning of the belt 18 relative to the traction sheave 20 and / or the deflector sheave 24.

[0022] Referring again to FIG. 2, the belt 18 includes plurality of tension members 32 extending along the belt 18 length and arranged across a belt width 34. In some embodiments, the tension members 32 are equally spaced across the belt width 34. The tension members 32 are at least partially enclosed in a jacket material 36 to restrain movement of the tension members 32 in the belt 18 and to protect the tension members 32. The jacket material 36 defines the traction surface 28 configured to contact a corresponding surface of the traction sheave 20. Exemplary materials for the jacket material 36 include the elastomers of thermoplastic and thermosetting polyurethanes, polyamide, thermoplastic polyester elastomers, and rubber, for example. Other materials may be used to form the jacket material 36 if they are adequate to meet the required functions of the belt 18. For example, a primary function of the jacket material 36 is to provide a sufficient coefficient of friction between the belt 18 and the traction sheave 20 to produce a desired amount of traction therebetween. The jacket material 36 should also transmit the traction loads to the tension members 32. In addition, the jacket material 36 should be wear resistant and protect the tension members 32 from impact damage, exposure to environmental factors, such as chemicals, for example.

[0023] In some embodiments, as shown in FIGs. 2 and 3, each tension member 32 is formed from a plurality of metallic, for example steel, wires 38, arranged into a plurality of strands 40, which are in turn arranged into a cord, or tension member 32. In other embodiments, the tension members 32 may be formed from other materials and may have other configurations. For example, in some embodiments, such as shown in FIG. 4, the tension member 32 may be formed from a plurality of fibers arranged in a rigid matrix composite. While in the embodiment shown there are six tension members 32 in the belt 18, the number of tension members 32 is merely exemplary. In other embodiments, for example, one, two, three, four, five, six or more tension members 32 may be utilized. It is to be appreciated that arrangement of wires 38 shown in FIG. 3 is merely exemplary, and that other arrangements of wires 38 to form tension members 32 are contemplated within the scope of the present disclosure.

[0024] Referring again to FIG. 2, the guidance of the belt 18 to the deflector sheave 24 and / or the traction sheave 20 is provided by one or more belt guide features 42 at the back surface 30 of the belt 18 that are configured to mesh with complimentary guide sheave features 44 of the guide sheave 26. In an embodiment of the invention, such as shown in FIG. 2, the belt guide features 42 each include a convex arc extending outwardly from the back surface 30, while the guide sheave features include a concave arc located at a guide sheave surface 50. In some embodiments, multiple guide features may be utilized across the belt width 34 as shown in FIG. 2, while in other embodiments, a single belt guide feature 42 and complimentary guide sheave feature 44 may be used to guide the belt 18.

[0025] Referring now to FIG. 5, in other arrangements, the belt guide features 42 and complimentary guide sheave features 44 may have other shapes, such as a "V"-shape or taper as shown. Further, a single belt guide feature 42 and complimentary guide sheave feature 44 may be utilized, as shown in FIG. 6. In the arrangement of FIG. 6, the "V"-shape is continuous over the entire belt width 34, but in other embodiments, the "V"-shape may extend partially across the belt width 34. The shapes and configurations of belt guide features 42 and complimentary guide sheave features 44 disclosed herein are merely exemplary, and one skilled in the art will recognize that other shapes and configurations of such features may be utilized.

[0026] Referring now to FIG. 7, illustrated is a traction sheave 20 and guide sheave 26 arrangement for an elevator system 10 having multiple belts 18. The traction sheave 20 includes a sheave location or groove 52 for each belt 18 of the elevator system 10. The guide sheave 26 includes multiple arrangements of guide sheave features 44, one set of guide sheave features 44 for each belt 18, which interact with the belt guide features 42 of each belt 18. The guide sheave surface 50 may be continuous across the multiple belt width, or as shown in FIG. 7, may comprise multiple guide sheave surfaces 50 supported by an axle 54. Further, as shown, in some embodiments, a biasing member 56 such as a spring may be utilized to bias a position of the guide sheave toward the belt 18, urging the guide sheave features 44 into interactive contact with the belt guide features 42 of the belt 18.

[0027] One concern with the addition of belt guide features 42 to the back surface 30 is a potential increase in stiffness of the belt 18, limiting the ability of the belt 18 to conform to the shape of the traction sheave 20 and / or the deflector sheave 24. In some embodiments, to reduce the stiffness of the belt 18, a height of the belt guide features 42 is below about 3mm. In some embodiments, the belt guide features 42 may be discontinuous along the belt 18 length. For example, as shown in FIG. 8, the belt guide features 42 may comprise a plurality of feature segments 58 extending along the belt 18 length. The feature segments 58 are separated by a feature gap 60, which results in a reduction of belt 18 stiffness compared to a belt 18 with continuous belt guide features 42. In other embodiments, such as shown in FIG. 9, the belt guide features 42 may be formed continuous along the belt 18 length, then segmented into feature segments 58 by a cutter or other tool, allowing the belt 18 to more readily conform to the traction sheave 20 and / or the deflector sheave 24. The Further, the guide features 42 may be formed from a material different from the jacket material 36 with a selected hardness so the effect of the guide features 42 on bending stiffness of the belt 18 is minimized. For example, in some embodiments the guide features 42 may be formed having a durometer hardness of between 60 and 80 on the Shore A hardness scale, while the traction surface 28 has a durometer hardness of over 80. The guide features 42 may be co-extruded with the jacket material 36 to form the belt 18 or alternatively may be formed separately and bonded to the jacket material 36 after the jacket material 36 is formed over the tension members 32.

[0028] A distance between the guide sheave 26 and the associated deflector sheave 24 or traction sheave 20 determines a "force" necessary to steer the belt 18 to the desired position at the deflector sheave 24 or traction sheave 20. The larger the distance, the smaller the force required. On the other hand the guide sheave 26 must be close enough to the associated deflector sheave 24 or traction sheave 20 to control the belt 18 position and effectively guide the belt 18. In some embodiments a distance between the guide sheave 26 and the associated deflector sheave 24 or traction sheave 20 is between about 0.2 and 2.0 times a deflector sheave 24 diameter or traction sheave 20 diameter.

[0029] Incorporating belt guide features 42 at the back surface 30 of the belt 18 allows for the removal of guide features such as crowns or the like from the traction sheave reducing the stress gradient across the belt width at the traction sheave thereby reducing wear of portions of the belt. Further, flanges typically utilized at the traction sheave to contain the belt at the traction sheave may be reduced or removed. Further still, since the belt guide features 42 and the guide sheave 26 align the belt 18 before encountering the traction sheave 20, a width of the traction sheave 20 may be reduced. 20 is between about 0.2 and 2.0 times a deflector sheave 24 diameter or traction sheave 20 diameter.

[0030] Incorporating belt guide features 42 at the back surface 30 of the belt 18 allows for the removal of guide features such as crowns or the like from the traction sheave reducing the stress gradient across the belt width at the traction sheave thereby reducing wear of portions of the belt. Further, flanges typically utilized at the traction sheave to contain the belt at the traction sheave may be reduced or removed. Further still, since the belt guide features 42 and the guide sheave 26 align the belt 18 before encountering the traction sheave 20, a width of the traction sheave 20 may be reduced.

[0031] The present invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A belt (18) for an elevator system (10) comprising: a plurality of tension members (32) arranged along a belt width (34); and a jacket material (36) at least partially encapsulating the plurality of tension members (32) defining: a traction surface (28) interactive with a traction sheave (20) of an elevator system (10); a back surface (30) opposite the traction surface (28), the back surface (30) including a belt guide feature (32) extending along a belt length and interactive with a complimentary guide sheave feature (44) of a guide sheave (26) of the elevator system (10) to orient the belt (18) to a selected location during operation of the elevator system (10); the belt guide feature (42) is a convex arc feature protruding outwardly from the back surface (30); and characterized in that the belt guide feature (42) is discontinuous along the belt length.

2. The belt (18) of claim 1, further comprising a plurality of belt guide features (42) arrayed across a width of the belt.

3. The belt (18) of any preceding claim, wherein the belt guide feature (42) has a curvilinear cross-section.

4. The belt (18) of any preceding claim, wherein the belt guide feature (42) comprises a plurality of belt guide feature segments (58) separated along the belt length by a plurality of feature gaps (60).

5. The belt (18) of any preceding claim, wherein the belt guide feature (42) has a lower durometer than the traction surface (28).

6. An elevator system (10) comprising: a hoistway (12); an elevator car (14) disposed in the hoistway (12) and movable along the hoistway (12); a traction sheave (20) with flat traction surfaces; and a belt (18) as claimed in any preceding claim operably connected to the traction sheave (20) and the elevator car (14) to move the elevator car (14) along the hoistway (12).

7. The elevator system (10) of any preceding claim, further comprising a biasing member (56) operably connected to the guide sheave (26) to bias the guide sheave (26) toward the belt (18).

8. The elevator system (10) of any preceding claim, wherein a distance between the guide sheave (26) and the traction sheave (20) is in the range of 0.2 times and 2.0 times a traction sheave (20) diameter.

9. The elevator system (10) of any preceding claim, further comprising a plurality of belts (18) arranged along a width of the flat traction sheave (20).