Belt clamp

Abstract

A belt clamp comprising a first body (10) having an arcuate surface (12), a second body (20) having an arcuate surface (22), a clevis (30) engageable between the first body arcuate surface (12) and the second body arcuate surface (22), the clevis having a form compatible with the first body arcuate surface and the second body arcuate surface, the clevis further having a substantially teardrop shape, a fastener (F) for securing the first body to the second body whereby a belt is clamped between the first body arcuate surface and the clevis and the second body arcuate surface and the clevis, and a receiver (16) for attaching the belt clamp to a mounting surface.

Description

FIELD OF THE INVENTION

The invention relates to a belt clamp comprising a first body having an arcuate surface, a second body having an arcuate surface, a clevis engageable between the first body arcuate surface and the second body arcuate surface, the clevis having a form compatible with the first body arcuate surface and the second body arcuate surface, the clevis further having a substantially teardrop shape, a fastener for securing the first body to the second body whereby a belt is clamped between the first body arcuate surface and the clevis and the second body arcuate surface and the clevis, and a receiver for attaching the belt clamp to a mounting surface.

BACKGROUND OF THE INVENTION

Typically, forklifts comprise a mast to which are connected forks for lifting loads. The lifting mechanism typically comprises chain. The chain can be fixed to the mast by a clevis. Further, chain requires periodic maintenance, including cleaning and lubrication.

It is known to use belts in lift applications, for example, for elevators. Clamps are known for fastening the belt end to a pulley or anchor. The clamps comprise plates extending across the belt with bolts extending through the plates and belt.

Further, leaf chain clamps (clevises) are standardized, by leaf chain size, for example, in the ASME B29.8-2002 Standard.

Representative of the art is U.S. Pat. No. 4,185,791 (1980) which discloses a device for preventing a belt from being pulled from a retractor comprises a clamp holder and a base member having closely spaced surfaces defining a gap through which the belt passes and from which the belt runs off forwardly at an angle away from the base member. The holder receives a clamp which has a gripping surface protruding slightly from the holder surface and, in part, defining the gap. The holder is pivoted on the base member, and the clamp and holder are spring-loaded about the pivot axis in a direction which holds the clamp out of engagement with the belt. An abrupt force tending to pull the belt abruptly forward through the gap forces the holder to pivot or rock rearwardly, thus engaging the gripping surface of the clamp with the belt. Forwardly oblique, transverse wedging surfaces on the clamp and clamp holder wedge the clamp tightly against the belt and prevent it from being pulled forward.

What is needed is a belt clamp comprising a first body having an arcuate surface, a second body having an arcuate surface, a clevis engageable between the first body arcuate surface and the second body arcuate surface, the clevis having a form compatible with the first body arcuate surface and the second body arcuate surface, the clevis further having a substantially teardrop shape, a fastener for securing the first body to the second body whereby a belt is clamped between the first body arcuate surface and the clevis and the second body arcuate surface and the clevis, and a receiver for attaching the belt clamp to a mounting surface. The present invention meets this need.

SUMMARY OF THE INVENTION

The primary aspect of the invention is a belt clamp comprising a first body having an arcuate surface, a second body having an arcuate surface, a clevis engageable between the first body arcuate surface and the second body arcuate surface, the clevis having a form compatible with the first body arcuate surface and the second body arcuate surface, the clevis further having a substantially teardrop shape, a fastener for securing the first body to the second body whereby a belt is clamped between the first body arcuate surface and the clevis and the second body arcuate surface and the clevis, and a receiver for attaching the belt clamp to a mounting surface.

Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.

The invention comprises a belt clamp comprising a first body having an arcuate surface, a second body having an arcuate surface, a clevis engageable between the first body arcuate surface and the second body arcuate surface, the clevis having a form compatible with the first body arcuate surface and the second body arcuate surface, the clevis further having a substantially teardrop shape, a fastener for securing the first body to the second body whereby a belt is clamped between the first body arcuate surface and the clevis and the second body arcuate surface and the clevis, and a receiver for attaching the belt clamp to a mounting surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention.

FIG. 1 is a top perspective side view of the belt clamp.

FIG. 2 is a partially exploded top perspective side view of the belt clamp.

FIG. 3 is a free body diagram of the belt clamp.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a top perspective side view of the belt clamp. The inventive belt clamp comprises a first body portion 10, a second body portion 20 and a clevis member 30. The body portions are held together with fasteners (F).

Body portion 10 comprises a concave arcuate portion 11 which extends lengthwise along a major axis A-A of the belt clamp. Arcuate surface 12 cooperatively engages a surface 31 on clevis 30. However, clevis 30 does not have a shape to come into contact with surface 12 because a belt (not shown) occupies the space (S1) between surface 31 and surface 12. A portion 13 extends normally from portion 14, causing body 10 to have an “L” shape.

Body portion 20 comprises a concave arcuate portion 21 which extends lengthwise along a major axis A-A of the belt clamp. Arcuate surface 22 cooperatively engages a surface 32 on clevis 30. However, clevis 30 does not have a shape to come into contact with surface 12 because a belt (not shown) occupies the space (S2) between surface 31 and surface 12.

Clevis 30 generally comprises what may be called a “teardrop” shape with the acute end 33 directed toward the end of the clamp through which the belt enters. Put another way, the acute end 33 of the clevis 30 is pointed toward the end through which the loaded portion of the belt enters the belt clamp.

In use clevis 30 is clamped between portion 10 and portion 20. A belt enters the clamp at “B”, wraps around clevis 30 and exits from the clamp at “B”, see FIG. 4.

FIG. 2 is a partially exploded top perspective side view of the belt clamp. Body 10 comprises holes 15, each for receiving a fastener such as a bolt. Body 20 comprises holes 23, each for receiving a fastener such as a bolt. Each hole 15 is cooperatively disposed with respect to a hole 23. A receiver 16 is used to threadably receive a rod for attaching the clamp to a mounting surface. In this embodiment receiver 16 comprises a threaded hole. Holes 15 and 23 may either be threaded or not, depending upon the fastener selected.

When in use a belt fits between each hole 15 so that the fasteners (F) do not pierce through the belt. Clevis 30 has a width (W2) that is approximately equivalent to the width (W) between holes 15. Clevis 30 is disposed between two or more fasteners such that its position within the belt clamp is laterally controlled. Width (W2) is less than the overall width (W3) of body portion 10 or body portion 20.

FIG. 3 is a free body diagram of the belt clamp. The clamp is intended as a drop-in replacement for chain in existing installations, such as on a fork lift truck, without any modification of the existing brackets or other features present on the vehicle.

In the case of the minimum work width for a belt, for example, a 30 mm wide flat belt with steel cord has a minimum work diameter of approximately 3″, the inventive solution is to divert the reaction force in a direction normal to the tensile load so as to minimize or eliminate the axial reaction force on the bent portion of the belt. In order to keep the belt from sliding out of the clamp under axial (tensile) load the clamp applies a lateral force by the fasteners used to close it.

The mechanical principles embodied in the clamp are depicted in FIG. 3.

FL=Lateral Clamping Force

FLN=Lateral Clamping Force Normal Component (normal to the contact surface)

FR=Reaction Force

FRN=Reaction Force Normal Component

FA=Axial Force

From FIG. 3, the two normal components (FLN, FRN) are additive so the clamping force (FL) on the belt is enhanced thereby preventing the belt from sliding out of the clamp. The lateral clamping force is generated by the fasteners. The axial force is the belt load as shown by belt segment B1. The reaction force is the belt load as transmitted into a mounting surface.

The load bearing portion of the belt entering the clamp is B1. The tail end of the belt is B2, which has no load. The belt enters the clamp and loops around the clevis 30. B1 and B2 are clamped between body 10 and body 20.

Although a form of the invention has been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein.

Claims

1. A belt clamp comprising:

a first body (10) having an arcuate surface (12);

a second body (20) having an arcuate surface (22);

a clevis (30) engageable between the first body arcuate surface (12) and the second body arcuate surface (22), the clevis having a form compatible with the first body arcuate surface and the second body arcuate surface, the clevis further having a substantially teardrop shape;

a fastener (F) for securing the first body to the second body whereby a belt is clamped between the first body arcuate surface and the clevis and the second body arcuate surface and the clevis; and

a receiver (16) for attaching the belt clamp to a mounting surface.

2. The belt clamp as in claim 1, wherein the first body comprises an “L” shape.

3. The belt clamp as in claim 1, wherein an acute end (33) of the clevis is pointed in a direction parallel to a belt axial force.

4. The belt clamp as in claim 1, wherein the acute end of the clevis is pointed toward the end through which the belt enters the belt clamp.

5. The belt clamp as in claim 1, wherein the clevis is entirely disposed between the first body and the second body.

6. The belt clamp as in claim 1, wherein the clevis is disposed between two or more fasteners.