Flat belt with looped terminal end

Abstract

Flat belts having a looped terminal end for connecting to application equipment. The flat belt has a body that has been doubled back on itself to form the looped terminal end of the belt. A rigid bushing is positioned around the looped body, the bushing having an annular shoulder at each lateral edge of the loop. The free end of the looped over body is laminated (e.g., adhered) to the belt body. A clamp may be added to better secure the free end to the body.

Description

FLAT BELT WITH LOOPED TERMINAL ENDCROSS-REFERENCE

[0001] This application claims priority to U.S. provisional application no. 63 / 693,508 filed September 11, 2024, the entire disclosure of which is incorporated herein by reference for all purposes.TECHNICAL FIELD

[0002] This disclosure is directed to flat belts, particularly, to methods and features for connecting the ends of the flat belts to equipment.BACKGROUND

[0003] Flat belts are available as an extended length of belt that are “open,” having a first distinct end and a second distinct end. Flat belts, in general, have rectangular cross-sections where the width is larger than the thickness. Flat belts can be adapted to a wide range of uses, such as for conveying, lifting, food & beverage, and industrial applications. In addition to use as conveyor belts and other material handling belts, flat belts are used, for example, as haul-off belts for haul-off of cables, pipes, wires and ropes, processing belts for the metal industry, e.g., to spool rolled metals or sheet metals into coils, winding belts for winding of paper and cardboard sleeves, and timing belts for the control of linear movements synchronous to conveyors and drive systems. Flat belts are also used in high load applications, such as in passenger elevators and forklifts, to provide the linear movement of the car and forks, respectively.

[0004] Flat belts are adapted to a wide range of mechanical requirements, with combinations of different types of materials and reinforcing cords designed for each application. Flat belts are available as high strength and low stretch for a long working service life. They are available with grooves, ribs, and flat (no topography).

[0005] Open ended flat belts typically are joined end-to-end or one or both ends is connected (mounted) to equipment. Typically, when connecting two belts together or connecting to equipment, a clamp is attached to the flat belt; the clamp is one that either applies direct1 Attorney docket B24-015W001 869048PCTpressure to the belt (e.g., by screwing) or that applies tangential pressure by using a wedge clamp. With both mechanisms, the force from the clamp (completely or in parts) is transferred to the flat belt by friction on the surface of the belt, which, unfortunately, allows possible slipping of the flat belt. Other known mechanisms pass a screw, bolt, or peg through the belt to inhibit slipping; however, these mechanism produce a weak point in the belt that may lead to a tear or break in the belt.

[0006] What is needed is a mechanism to better hold a flat belt and that has easy assembly as well.SUMMARY

[0007] The present disclosure provides a looped terminal end on a flat belt. The looped end allows the belt to be directly fixed to application equipment without additional belt assembling or modification steps by the user. The looped end allows use of the flat belt in tight environments, where clearance space is minimal.

[0008] The present disclosure also provides methods of making the looped end, the methods including laminating the belt upon itself forming a loop. The lamination can be via welding, thermal adhesion, or by an added adhesive. A rigid bushing is positioned around the resulting loop, providing a more durable construction and enabling higher forces to be transmitted, increasing loop strength under both pulling and pushing conditions. A clamp may be applied over the laminated belt sections, proximate the belt loose end.

[0009] In one particular implementation, this disclosure provides a flat belt having a body with a first free end and a second free end, and a looped terminal end of the belt formed by a loop of the body. The first free end is spaced medially from the terminal end and laminated to the body. A bushing is present around the loop at the terminal end, the bushing having an annular shoulder at each lateral edge of the loop.

[0010] In another particular implementation, this disclosure provides a method of making a looped terminal end on a flat belt. The method includes providing a flat belt having a belt body with a first free end and a second free end, doubling the first free end back on the belt body forming a loop, after forming the loop, laminating the first free end to the belt body, and after forming the loop, installing a bushing around the loop, the bushing having an annular shoulder at each lateral edge of the loop.2 Attorney docket B24-015W001 869048PCT

[0011] In yet another particular implementation, this disclosure provides a method of connecting a flat belt to equipment. The method includes passing a connector through a looped terminal end of a flat belt, and attaching the connector to the equipment.

[0012] Other implementations are also described and recited herein.

[0013] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWING

[0014] FIG. 1 is perspective view of a portion of a flat belt.

[0015] FIG. 2 is a perspective view of a flat belt with both ends being looped ends.

[0016] FIG. 3 is an enlarged perspective view of a flat belt having a looped end.

[0017] FIG. 4A is perspective view of another looped end with a retaining bushing; FIG.4B is a cross-sectional side view of the end loop and part of a retaining bushing; FIG. 4C is a cross-sectional view of the looped end taken along line C-C of FIG. 4A.

[0018] FIG. 5 is a stepwise method of forming a terminal loop in a flat belt.

[0019] FIG. 6A is a stepwise first method of attaching a flat belt to equipment; FIG. 6B is a stepwise second method of attaching a flat belt to equipment.DETAILED DESCRIPTION

[0020] As indicated above, the present disclosure is directed to belts having a looped end through which a connector or fastener can be inserted, the fastener for connecting the belt end to application equipment. The end loop is formed by folding an open-ended flat belt back on itself to form an aperture through the looped end and laminating the free end of the belt to the belt body. An external, rigid bushing is positioned around the resulting loop. This looped end of the belt can be directly fixed to application equipment without additional assembling steps (e.g., applying a clamp) for the end user.3 Attorney docket B24-015W001 869048PCT

[0021] The design of flat belts has evolved to produce belts that are comparable in strength to steel ropes but with increased flexibility and fatigue characteristics. Flat belts are replacing chains, steel straps, and cables. Equipment or applications evolving to use flat belts include elevators and forklifts and other pulling and vertical lifting applications.

[0022] There are two typical mounting mechanisms for attaching open ended flat belts to fixtures - clamping the flat belt in a clamp by applying direct pressure to the surface faces of the belt (e.g., by screwing), and by clamping the flat belt in a wedge clamp. With both mechanisms, the force from the clamp is transferred to the flat belt by friction on the surface of the belt, which, unfortunately, allows possible slipping of the flat belt.

[0023] Clamping via fasteners such as screws can damage the belt if too much torque is applied to the fasteners. If too little clamping force is applied, the belt can slip, which can also damage the belt. To inhibit such slipping, bolts, screws, pegs, studs, etc. may be inserted through the belt, which may damage the belt even further. For some clamp and flat belt combinations, the belt / clamp interface area needed for a successful engagement is fairly high, leading to a physically large clamp; in some applications, a large clamp is not practical, e.g., due to space constraints.

[0024] Similarly, wedge clamps, which are placed at a looped end of a flat belt, are larger than clamps for cables or chain drives that have similar forces. Additionally with wedge clamps, no matter the type of belt, if the force or tension on the clamped belt reverses or even loosens, the clamp can inadvertently release the belt.

[0025] Having a looped end reduces, and practically minimizes, the required clearance space needed for attachment of the flat belt to the application equipment. The belt with a looped end described below is a solution for tight conditions, particularly where there is little or no clearance for cross screwing of plates and / or screws / bolts or threading into a wedge clamp.

[0026] In the following description, reference is made to the accompanying drawing that forms a part hereof and in which is shown by way of illustration at least one specific implementation. The following description provides additional specific implementations. It is to be understood that other implementations are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense. While the present disclosure is not so limited, an appreciation of various aspects of the disclosure will be gained through a discussion of the4 Attorney docket B24-015W001 869048PCTexamples, including the figures, provided below. In some instances, a reference numeral may have an associated sub-label consisting of a lower-case letter to denote one of multiple similar components. When reference is made to a reference numeral without specification of a sublabel, the reference is intended to refer to all such multiple similar components.

[0027] Turning to the figures, FIG. 1 shows a generic belt 100 having a body 102 formed of a flexible material having a back side 104 and a front side 106 with a plurality of load carrying cords 108 within the body 102, the particular cords 108 in FIG. 1 bound in triplicate bundles although in other embodiments the cords 108 may be single cords or bundled otherwise. The cords 108 may be, e.g., metal (e.g., steel) wires or cords, carbon cords, polymeric cords (e.g., polyester, aramid), fiberglass cords, etc. The belt 100 is a “flat belt,” having two free ends; that is, the belt is not a looped endless belt.

[0028] The belt 100 may be any polymeric or rubber belt; that is, the belt 100 is not a metal belt. The belt 100 may include, e.g., metal cords 108. Examples of suitable materials for the belt 100 include polyurethane, polypropylene, polyolefin, vulcanized rubber, thermoplastic elastomer, and various blends thereof.

[0029] A suitable polyurethane material for the belt 100 is one that is a reaction product of a urethane prepolymer (e.g., based on a polyether and a linear aliphatic diisocyanate) and a diamine chain extender.

[0030] Other suitable materials for the belt 100 are polyurethane / urea elastomers prepared by reacting polyisocyanate prepolymers with symmetric primary diamine chain extenders, mixtures of symmetric primary diamine chain extenders and secondary diamine chain extenders, or mixtures of symmetric primary diamine chain extenders and non-oxidative polyols. The polyisocyanate prepolymers can be formed from polyols, such as polycarbonate polyols and polyester polyols.

[0031] Another particular material suitable for the belt 100 is a polymer blend of nitrile and ethylene terpolymers, particularly, a composition with an acrylonitrile-butadiene copolymer (NBR) and ethylene polymers. The composition may have NBR as 30 to 50 wt.-% of the total blend and the ethylene polymer can be 20 to 40 wt.-% of the total blend. In some embodiments, the ethylene polymer is EPDM rubber (which is a well-known rubber made from ethylene, propylene, and a diene comonomer that enables crosslinking via sulfur vulcanization). In other embodiments, the ethylene polymer is an ethylene acrylic elastomer. In yet other embodiments,5 Attorney docket B24-015W001 869048PCTthe ethylene polymer is a chlorinated polyethylene. The composition can include an organic peroxide or other accelerator.

[0032] Another particular material suitable for the belt 100 is a rubber composition having a polymer blend of at least two ethylene polymers, with one of the polymers a halogenated polyethylene (a halogenated ethylene polymer). In some embodiments, the halogenated polyethylene is a chlorinated polyethylene rubber. In some embodiments, the ethylene polymer is an ethylene acrylic elastomer. In some other embodiments, the ethylene polymer is EPDM rubber (which is a well-known rubber made from ethylene, propylene, and a diene comonomer that enables crosslinking via sulfur vulcanization). The halogenated ethylene polymer can be 25 to 50 wt.-% of the total blend and the ethylene polymer at 10 to 30 wt.-% of the total blend, with the remainder being ingredients such as activators, fillers, curing agents, reinforcing materials, antidegradants (e.g., antioxidants, UV stabilizers), plasticizers, antistatic agents, colorants, processing aids, homogenizers, coagents, catalysts, and the like. The composition can include an organic peroxide or other accelerator.

[0033] The cord 108, as indicated above, be single cords or bundled and may be, e.g., metal, carbon, polymeric, fiberglass, etc. The cord 108 may be coated or impregnated with an adhesive composition. One particular adhesive composition is a reaction product of a polyisocyanate and a polyol, or a polyurethane prepolymer derived therefrom, and a poly amine curative and optionally additional polyol, and with optionally added plasticizer. At least one of the polyisocyanate, the prepolymer, and the polyamine are blocked with a blocking agent.

[0034] Another adhesive composition for impregnating the cord and / or coating the fibers is a polyurea-urethane adhesive.

[0035] The belt 100 can be formed by any conventional and / or suitable technique, including extruding, casting, machining, molding, etc.

[0036] FIG. 2 shows a flat belt 200 having an extension of an elongate body 202 having a back side 204 and a front side 206 with a plurality of grooves 208 in the front side 206; other belts may be lacking such grooves. The belt 200 has two looped terminal ends 210 and 220. Rather than having to mount the flat belt 200 to equipment with a clamp, screws / bolts or wedge clamp as described above, the ends 210, 220 are ready to be installed with a connector to equipment.6 Attorney docket B24-015W001 869048PCT

[0037] Each looped terminal end 210, 220 is formed by folding or looping the body 202 back over on itself so that, at the ends 210, 220, the front side 206 is in contact with itself while leaving an aperture 215 between the two front sides 206 at the terminal end. It is noted that in some embodiments the belt body 202 is looped so that the back side 204 is in contact with itself.

[0038] In some embodiments, only one of the ends of the belt is formed with a terminal loop, the other end being left as a free end.

[0039] Turning to FIG. 3, a looped terminal end of a flat belt 300 having a back side 304 and a front side 306 is shown as looped end 310. The looped end 310 is formed by folding or looping the free end 308 of the body 302 back over on itself so that the front side 306 is in contact with itself at an interface 305. In other embodiments, the belt 300 may be looped so that the back side 304 is in contact with itself. The looped belt forms an aperture through which or into which a connector such as a bolt B can be passed or received. The bolt B or other similar connector would connect to or engage with the equipment to which the belt is being attached.

[0040] Around the looped belt end is a rigid bushing 350 for providing a structure to and strengthening the end 310. Additional details regarding the bushing 350 are provided with respect to FIGS. 4A, 4B and 4C, below.

[0041] At the folded portion of the belt body 302 (that is, the section of the belt 300 having a double layer of the body 302), the two sections of the body 302 are joined or otherwise sealed together without any screw, bolt, peg or the like penetrating through or into the body 302. The joining can be referred to as lamination and can be via welding, thermal adhesion, or by an added adhesive; the joining is not a mechanical joint or joining, e.g., using screws, bolts, staples, stitching, etc.

[0042] Any suitable non-mechanical method can be used to join the belt body and form the interface 305. For example, the joining can be done by the application of heat and pressure (lamination) optionally with ultrasonics. A solvent can be applied to partially soften and / or melt or dissolve the surface of the belt material. Alternately, an appropriate adhesive can be used.

[0043] An optional clamp 360 can be placed to better secure the free end 308 to the body 302. The clamp 360 can be positioned between the looped end 310 and the free end 308. The clamp 360 is a pressure clamp and does not pass through or penetrate into the body 302, as would a screw, peg, etc.7 Attorney docket B24-015W001 869048PCT

[0044] Turning to FIGS. 4A, 4B and 4C, a looped terminal belt end 410 is shown with a bushing or part thereof in each of FIGS. 4 A, 4B and 4C.

[0045] The looped end 410 is the terminal end of a flat belt that has been bent or looped over on itself to form an arcuate section 401. The arcuate section 401 is continuous with a first belt body segment 402a and a second belt body segment 402b joined at an interface 405. The arcuate section 401 is shaped and sized to receive a connector such as bolt B, seen installed within the looped end 410 in FIG. 4B .

[0046] Around the arcuate section 401 is a rigid bushing 450 formed from a strong, durable material such as steel or iron. The bushing has two lateral pieces 452, 454, each with an aperture 415 therethrough. FIG. 4B is a cross-sectional view taken at the interface of the two lateral pieces 452, 454; thus, only one lateral piece 452 is seen. Each lateral piece 452, 454 has an outer edge annular shoulder 462, 464, respectively, which extends laterally past the edges of the belt segments 402a, 402b when the pieces 452, 454 are joined or engaged around the belt segments; see FIG. 4C. That is, the arcuate section 401 sits medially within the annular shoulders 462, 464. Each annular shoulder 462, 464 has a respective annular outer face 472, 474.

[0047] By having a looped belt end with a rigid bushing 350, 450, rather than a clamping plate or a wedge clamp, the clearance needed to connect the belt to the equipment is greatly reduced; usually only about 50% of the clearance is needed for connecting a looped belt compared to connecting a flat belt using a clamping plate or a wedge clamp.

[0048] FIG. 5 shows an example of a clamping plate suitable for securing the free end of the belt to the body proximate the free end, as does the clamp 360 of FIG. 3.

[0049] FIG. 5 shows a flow chart of a method 500 for forming a terminal loop in an end of a flat belt. In step 502, a flat belt, such as the belt 100 of this description and variants thereof, is provided. The flat belt has at least one free end. In step 504, a free end of the flat belt is doubled back on itself, forming a loop. In step 606 subsequent to step 504, the free end is connected to the body of the belt, e.g., by lamination, welding, adhesion, etc. In step 508, a rigid bushing is installed around the loop. In some embodiments, the rigid bushing has two halves, one half installed from each edge of the belt and optionally connected together. In an optional step 510, a clamp is positioned on the belt, around the laminated free end and the belt body. The steps 508, 510 may be done in either order; that is, step 510 could be done before step 508.8 Attorney docket B24-015W001 869048PCT

[0050] The same method 500 could be done to form a terminal loop in the other end of the same flat belt.

[0051] FIGS. 6A and 6B show flow charts of methods for attaching a flat belt having a terminal loop, such as the belt 200 of this description and variants thereof, to equipment.

[0052] In method 600 in FIG. 6A, the looped end is attached directly to application equipment. In step 602, the looped end of the belt is placed on the equipment, such as a fixed bolt or stud, so that the looped end engages with the equipment. In step 604, a fastener, such as a nut, cotter pin, etc., is appropriately attached the bolt or stud having the belt thereon, to secure the belt to the equipment.

[0053] In method 610 in FIG. 6B, a connector is placed through the looped end, which is then connected to application equipment. In step 612, a connector such as a bolt is placed through the aperture in the looped end of the belt. In step 614, the connecter is then securely attached or connected to the equipment. As an example, the connection to the equipment may be via a clevis.

[0054] In both methods 600, 610 and variations thereof, the free end of the flat belt opposite the looped end of the methods 600, 610 may also be connected to application equipment in the same or similar manners.

[0055] As indicated above, the belt 100 and any variations thereof may be formed by any suitable techniques, including extruding, casting, machining, molding, etc. with appropriate materials for the particular joining method employed. The belt 100 is made to withstand the forces applied to the belt. Similarly, the bushing 350, 450 is made to withstand the forces applied thereto and may be formed by any suitable technique such as casting, machining, molding, etc. Examples of suitable materials for the bushing 350, 450 and variations thereof include metal (e.g., iron, steel, stainless steel, nickel, iron, aluminum, alloys) and ceramic materials.

[0056] The above specification and examples provide a complete description of the structure and use of exemplary implementations of the invention. It will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the scope of the invention. It is to be understood that other implementations are contemplated and may be made without departing from the scope or spirit of the present disclosure. The above detailed description,9 Attorney docket B24-015W001 869048PCTtherefore, is not to be taken in a limiting sense. Various features and details have been provided in the multiple designs described above. It is to be understood that any features or details of one design may be utilized for any other design, unless contrary to the construction or configuration; any variations may be made. While the present disclosure is not so limited, an appreciation of various aspects of the disclosure will be gained through a discussion of the examples provided. The invention is not limited except as by the appended claims.

[0057] Although the technology has been described in language that is specific to certain structures and materials, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures and materials described. Rather, the specific aspects are described as forms of implementing the claimed invention.

[0058] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties are to be understood as being modified by the term “about,” whether or not the term “about” is immediately present. Accordingly, unless indicated to the contrary, the numerical parameters set forth are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0059] As used herein, the singular forms “a”, “an”, and “the” encompass implementations having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0060] Spatially related terms, including but not limited to, “bottom,” “lower”, “top”, “upper”, “beneath”, “below”, “above”, “on top”, “on,” etc., if used herein, are utilized for ease of description to describe spatial relationships of an element(s) to another. Such spatially related terms encompass different orientations of the device in addition to the particular orientations depicted in the figures and described herein. For example, if a structure depicted in the figures is turned over or flipped over, portions previously described as below or beneath other elements would then be above or over those other elements.

[0061] Because many embodiments of the invention can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.10 Attorney docket B24-015W001 869048PCT

Claims

WHAT IS CLAIMED IS:

1. A flat belt comprising: a body having a first free end and a second free end, and a looped terminal end of the belt formed by a loop of the body, with the first free end spaced medially from the terminal end and laminated to the body, and with a bushing around the loop at the terminal end, the bushing comprising an annular shoulder at each lateral edge of the loop.

2. The flat belt of claim 1, further comprising a clamp around and proximate the first free end and the body.

3. The flat belt of claim 2, wherein the clamp does not penetrate into the body.

4. The flat belt of claim 1, further comprising an adhesive between the first free end and the body where laminated to the body.

5. The flat belt of claim 1, wherein the bushing comprises a first piece and a second piece that engage over the loop.

6. The flat belt of claim 1, wherein the annular shoulders each have an annular outer face.

7. The flat belt of claim 1, further comprising a second looped terminal end of the belt formed by a second loop of the body, with the second free end spaced medially from the second terminal end and laminated to the body, and with a second bushing around the second loop at the second terminal end, the second bushing comprising an annular shoulder at each lateral edge of the second loop.11 Attorney docket B24-015W001 869048PCT8. A method of making a looped terminal end on a flat belt, the method comprising: providing a flat belt having a belt body with a first free end and a second free end; doubling the first free end back on the belt body forming a loop; after forming the loop, laminating the first free end to the belt body; and after forming the loop, installing a bushing around the loop, the bushing comprising an annular shoulder at each lateral edge of the loop.

9. The method of claim 8 further comprising: installing a clamp around the doubled first free end and the belt body.

10. The method of claim 9, wherein installing the clamp comprises: pressure fitting the clamp around the doubled first free end and the belt body.

11. The method of claim 8, wherein laminating the first free end to the belt body comprises applying heat and pressure.

12. The method of claim 8, wherein laminating the first free end to the belt body comprises applying ultrasonic welding.

13. The method of claim 8, wherein laminating the first free end to the belt body comprises applying an adhesive at an interface between the doubled first free end and the belt body.

14. The method of any of claims 8 to 13, further comprising: doubling the second free end back on the belt body forming a second loop; after forming the second loop, laminating the second free end to the belt body; and after forming the second loop, installing a second bushing around the second loop, the second bushing comprising an annular shoulder at each lateral edge of the second loop.12 Attorney docket B24-015W001 869048PCT15. A method of connecting a flat belt of any of claims 1 to 7 to equipment, the method comprising: passing a connector through a looped terminal end of a flat belt; and attaching the connector to the equipment.

16. The method of claim 15, wherein the passing the connector through the looped terminal end is done before attaching the connector to the equipment.

17. The method of claim 15, wherein the passing the connector through the looped terminal end is done after attaching the connector to the equipment.13 Attorney docket B24-015W001 869048PCT

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