FIELD OF DISCLOSURE

This disclosure relates to clamp assemblies specifically designed for clamping conveyor belts which may permit temporary clamping to facilitate repair or maintenance work.

BACKGROUND OF DISCLOSURE

Conveyor belts, especially in mining and industrial applications, can be large, for example being hundreds of meters (or even longer than a kilometer in extreme cases) and several centimeters thick. This makes the conveyor belts incredibly heavy and difficult to handle. This becomes problematic when servicing or repairing a conveyor belt.

Accordingly, conveyer belt clamps (or, more accurately, clamp assemblies) have been developed. An example of such a clamp assembly is disclosed in AU740976. Conveyor belt clamp assemblies of which the Applicant is aware usually include two beams (or arms) which are elongate and define two opposed clamping faces to be provided either side of a conveyer belt to be clamped; in other words, the conveyor belt is sandwiched between the beams. Two clamps are provided at either end of the beams to provide an inward clamping force to urge the beams together thereby to clamp the conveyor belt between the clamping faces. The clamp assembly is intended to be portable so that it can be provided (temporarily) at a location where the conveyor belt needs attention; sometimes, two clamps are required to be spaced a short distance apart so that an area of the conveyor belt between the clamps can be serviced, e.g., severed, joined, repaired, etc.

While this principle works, it also has its challenges. Given the sheer bulk and heft of some conveyor belts, the clamp assemblies need to be strong and robust. Making the clamps and/or beams of steel may make the clamping assemblies strong, but steel is heavy, so portability may be sacrificed. Conversely, more portable clamping assemblies include beams made of aluminum or aluminum alloy, optionally of hollow section. This makes the beams, and accordingly the clamp assembly, much lighter, but aluminum is not a strong as steel. More specifically, aluminum tends to bend or deform under a lighter load than steel.

Accordingly, the Applicant desires a clamp assembly which overcomes or ameliorates these problems; more specifically, the Applicant desires a clamping assembly suitable for clamping conveyor belts which is sufficiently light to be conveniently portable, but which is also sufficiently strong to provide functional clamping force for conveyor belts, considering the size and weight of some of these conveyor belts.

SUMMARY OF DISCLOSURE

Accordingly, the disclosure provides a clamp assembly for a conveyor belt, the clamp assembly including: a pair of elongate beams defining opposing clamping faces configured to accommodate the conveyor belt there-between; a pair of clamps configured to be provided respectively at each end of the beams, operable to impart a clamping force to the beams, wherein: the opposed clamping faces are convexly curved (thus having a convex curvature) to compensate, at least partially, for bending in the beams caused by the clamping force.

The Applicant notes that this solution is an unusual approach to the problem of bending. All other clamping assemblies of which the Applicant is aware either accept the bending or try to prevent it by making the beams stronger (i.e. , less susceptible to bending). The approach of permitting bending but compensating for it is a departure from the conventional wisdom in this particular field.

Differently stated, each beam may have a length-varying cross-sectional profile, with a height aspect of the profile being smaller at opposite ends of the beam in the region of the clamping face and larger in the middle of the beam in the region of the clamping face.

The curvature may be arcuate. The curvature may be uniform and part-circular, e.g., defined by a fixed radius of curvature. However, in different examples, the term “curvature” may not necessarily imply circular curvature and the clamping faces may have a stepped or compound linear profile which approximates a curve or arc, which is still considered to be “curvature” for the purposes of this specification.

Bending can be calculated by means of established mathematical formulae in the field of material science. For example, the bending of a beam supported at both ends may be a function of a length between the supports, a force (e.g., a distributed load or a point load), and a characteristic of the material of the beam (e.g., given by or derived from Young’s Modulus). The calculation may yield a radius of curvature to which the clamping faces should conform.

Accordingly, a particular curvature of the clamping face of the beam may be calculated so that, when used and clamped as at rated clamping force or as intended, each beam may bend to negate the convex curvature and become flat or approximately flat. This may provide a more evenly distributed clamping force along a length of the beams and therefore along a width of the conveyor belt.

This may overcome one of the significant drawbacks of prior art clamp assemblies in which the clamping force tends to be unequally distributed, being focused on sides of the belt and being reduced in a middle of the belt. In fact, in more extreme situations, the clamping force in the middle may be so poor that the belt may pull free from the middle but remain clamped at the sides, meaning that the belt deforms or warps. This could damage the belt but also result in inefficient, even skew or unbalanced, repair work.

The beams may be of aluminum (or aluminium) or aluminum alloy.

The beams may be hollow, having a square or rectangular cross-sectional profile. The beams, if hollow, my include intermediate walls to increase structural rigidity.

The clamping surface may include gripping formations. The gripping formations may be in the form of longitudinally extending grooves and ridges, e.g., resembling fluting. The gripping formations may further increase structural rigidity. The gripping formations may include oblique grooves, e.g., in a crisscross formation.

The beams may be identical but orientated, in use, oppositely. The beams may be symmetrical.

The clamps may resemble prior art clamps. The clamps may each have a C-shaped body or frame and a rotatable screw defining a pair of opposed jaws or shoes, one jaw being fixed on the frame and the other being displaceable on the screw. The clamp may include a handle (e.g., pin or crank) to drive/rotate the screw. The disclosure also provides for a clamp made from interlocking parts; more specifically, a body of the clamp may be of interlocking parts. The interlocking clamp may comprise: at least two side parts; at least one crosspiece configured to extend between the two side parts; and at least one rear part configured to provide a back piece.

There may be a pair of crosspieces, namely an upper crosspiece and a lower crosspiece. The crosspieces may extend between an operative front of the clamp body. The crosspieces may be configured to provide one or both opposed jaws or to provide structures (e.g., a threaded socket) to accommodate other parts (e.g., a rotatable screw) which provide one or both jaws.

There may be plural rear parts to provide the back piece and these rear parts may be interlocking. There may be four rear parts, e.g., two side, a top and a bottom. The back piece may define a large central aperture therein to permit through-passage of beams to be clamped.

The parts may define relatively interlocking formations, e.g., spigot and socket, lug and hole, groove and slot, etc.

The clamp may include a plurality of fasteners configured to fasten the parts together. The fasteners may be mechanical fasteners, e.g., screws or bolts. This may be fastened in the future with another method such as welding.

A pair of interlocking clamps may be used as the clamps in the clamp assembly, as defined above. The disclosure extends to a method of manufacturing a beam for use in a clamp assembly as defined above, the method including: extruding the beam to have a constant cross-sectional profile along its length; and machining or working the beam to remove more material at the ends of the clamping face than in the middle, thereby to create the convex curvature in the clamping face.

The method may include creating and using an extrusion die defining the constant cross-sectional profile. The method may include creating beams of different lengths from a single extrusion die.

The method may include: creating a shorter beam or a beam with a larger radius of curvature by removing more material in the middle (but still less than at the ends); or creating a longer beam or a beam with a smaller radius of curvature by removing less or no material in the middle.

BRIEF DESCRIPTION OF DRAWINGS

The disclosure will now be further described, by way of example, with reference to the accompanying diagrammatic drawings.

In the drawings:

FIG. 1 shows a three-dimensional view of a clamp assembly in accordance with the disclosure;

FIG. 2 shows a longitudinal sectional view of the clamp assembly of FIG. 1 ;

FIG. 3 shows a longitudinal sectional view of beams forming part of the clamp assembly of FIG. 2; FIG. 4 shows an enlarged longitudinal sectional view of the beams of FIG. 3;

FIG. 5 shows an end view of the beams of FIG. 3;

FIG. 6 shows a low-angle three-dimensional view of the clamp assembly of FIG. 1 ;

FIG. 7 shows a longitudinal section of the clamp assembly of FIG. 2, in use;

FIG. 8 shows a schematic view of clamping force applied by the clamp assembly of FIG. 1 ;

FIG. 9 shows a schematic view of clamping force applied by a PRIOR ART clamp assembly;

FIG. 10 shows a three-dimensional front view of an interlocking clamp forming part of a clamp assembly in accordance with the disclosure;

FIG. 11 shows a three-dimensional rear view of the interlocking clamp of FIG. 10;

FIG. 12 shows an exploded view of the interlocking clamp of FIG. 10;

FIG. 13 shows a low-angle three-dimensional view of an alternative version of the beam of FIG. 3;

FIG. 14 shows a three-dimensional view of the beam of FIG. 13; and

FIG. 15 shows a three-dimensional view of an alternative version of the clamp assembly of FIG. 1.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT

The following description of an example embodiment of the disclosure is provided as an enabling teaching of the disclosure. Those skilled in the relevant art will recognize that changes can be made to the example embodiment described, while still attaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be attained by selecting some of the features of the example embodiment without utilizing other features. Accordingly, those skilled in the art will recognize that modifications and adaptations to the example embodiment are possible and can even be desirable in certain circumstances and are a part of the present disclosure. Thus, the following description of the example embodiment is provided as illustrative of the principles of the present disclosure and not a limitation thereof.

FIGS 1 -2 illustrate a clamp assembly 100, in accordance with the disclosure, for clamping a conveyor belt 10. The clamp assembly 100 has a pair of elongate beams 130, 132 and a pair of clamps 110, 112 provided respectively at either end of the beams 130, 132.

The clamps 110, 112 include many features common to conventional clamps in this field. Each clamp 110, 112 has a generally C-shaped clamp body 114 accommodating a rotatable screw 115 with a pin handle 116 at its top and a movable jaw 118 at its bottom. The clamp body 114 defines a fixed jaw 119 (see FIG. 2) below the movable jaw 118. The clamp body 114 has a shackle 120 (e.g., a robust D-shackle) attached thereto which may be used to fasten or anchor the clamps 110, 112 and hence the whole clamp assembly 100.

The clamp assembly 100 has two beams 130, 132 which are elongate and span at least a width of the conveyor belt 10 and usually project some distance past sides of the conveyor belt 10. The beams 130, 132 are sized, specifically their length dimension, to suit a particular conveyor belt specification. For example, beams 130, 132 with a length of 1 .5 m (~5 ft) may be configured to fit/clamp conveyor belts 10 with a width of 0.9-1 .2 m (~3-4 ft). The wider the conveyor belt 10, the longer the beams 130, 132 need to be. Each beam 130, 132 has an inwardly directed clamping face 134; in use, the two clamping faces 134 are opposed and accommodate the conveyor belt 10, clamping it therebetween.

It is usually desired to make the clamp assembly 100 as light as practicable, given that it is intended to be portable and carried to a conveyor belt, or area of a conveyor belt, needing repair or maintenance work. Accordingly, the beams 130, 132 are of aluminium or aluminium alloy which is lighter than steel. Also, the beams 130, 132 are hollow to save material and weight. In this example, the beams 130, 132 have a rectangular cross-sectional profile with a central upright reinforcing rib (see FIG. 5).

The bigger/heavier the conveyor belt 10, the more clamping force is needed from the clamps 110, 112, so a size or grade of the clamps 110, 112 may also be specified for a particular size (or range of sizes) of conveyor belt 10. Bigger (and heavier) conveyor belts necessitate bigger clamps which can exert a greater clamping force. Typically, the conveyor belts in industrial or mining environments are relatively wide (greater than 0.5 m, and even greater than 1.0 m) and can be very long, making them heavy. The conveyor belt 10 can weigh hundreds of kilograms and even tons (1.0 ton « 1.1 US ton). Large clamping forces are therefore needed, and clamping forces at this scale will cause the beams 130, 132 to deform, resulting in bending.

Accordingly, a principle of this present disclosure is to provide the clamping faces 134 with a convexly curved profile approximately opposite to a predicted amount of bending/deformation. An amount of curvature may be relatively small compared to the length of the beams 130, 132. If measured as a radius of curvature, the radius of curvature of the clamping faces 134 may be greater, even multiples greater, than the length of the beams 130, 132. For example, the beams 130, 132 may have a length of 1 m and the radius of curvature may be 20 m, meaning that a middle of the beams 130, 132 will be about 2.5 cm (~1 in) thicker than at ends of the beams 130, 132.

It can be difficult to illustrate smaller differences (e.g., 2.5 cm) in larger structures (e.g., beam lengths of 1 m+), but FIGS 3-6 endeavor to show this feature in various views. FIGS 3-5 show the beams 130, 132 in isolation. The curvature of the clamping surface 134 is visible (particularly in FIGS 4-5) in that a thickness of the middle (indicated by numeral 136) of the clamping face 134 is greater than a thickness of the end (indicated by numeral 135).

The clamping faces 134, in this example, also include alternating grooves and ridges, or fluting, which are intended to assist with gripping by providing gripping surfaces (best seen in FIG. 5). This is not necessarily related to the curvature aspect, but it may be useful to the operation of the clamp assembly 100 overall. Further, the grooves may serve to make the beams 130, 132 lighter (by removing material) but the ridges between the grooves may maintain the structural rigidity of the beams 130, 132; accordingly, the grooves may make the beams 130, 132 more rigid per unit weight.

FIG. 6 illustrates a “low angle” view (with a proximate clamp 112 removed and a distal clamp 110 illustrated) in which the curvature of the opposed clamping faces 134 can be seen. As mentioned above, relatively speaking, the curvature of the clamping faces 134 may be small compared to the length of the beams 130, 132. The difference between the thickness of the middle and end (136, 135) may be in the order of cm, e.g., 1-5 cm (~0.4-2 in).

The amount of curvature may be calculated based on known material science equations using input variables including, for example, rated clamping force, width of the conveyor belt or length of the beams 130, 132, bendability/elasticity of the beams 130, 132 (e.g., using Young’s modulus), etc.

FIG. 7 shows the clamp assembly 100 in use. The clamps 110, 112 have been clamped by actuating the handles 116 to drive the screws 115 inwardly to a rated clamping force; this may be done in accordance with conventional clamp-actuating techniques, e.g., using a torque wrench. As the clamping force is applied, the clamps 110, 112 urge the beams 130, 132 inwardly at their ends and the beams 130, 132 begin to deform. Once the rated clamping force has been reached, the deformation/ending of the beams 130, 132 should (at least, approximately) counteract the curved clamping face 134 to make it flat.

Granted, the clamping surfaces 134 may not be 100% linear and flat, as practical inconsistencies (e.g., in the conveyor belt 10) may be difficult to predict, but it will become approximately flat. Accordingly, the clamping force transmitted to the conveyor belt 10 from the beams 130, 132 will be relatively uniform and evenly distributed across the width of the conveyor belt 10 (or higher in a middle than at sides of the belt). In fact, outer faces (on opposite sides of the beams 130, 132 as the clamping faces) will bulge outwardly.

This more evenly distributed clamping force 190 is illustrated in FIG. 8 which shows the beams 130, 132 in their clamped condition (corresponding to FIG. 7 but with bent surfaces slightly exaggerated). It should be noted that the clamping force from the clamps 110, 112 is translated by the beams 130, 132 to an evenly (or at least more evenly) distributed clamping force 190 along the width of the conveyor belt 10.

Contrast this with FIG. 9 which illustrates a PRIOR ART clamp assembly 20 having flat beams 22 (that is, without a convexly curved clamping face). The whole beams 22 have bent, including their clamping face now being concavely curved, and transmit an uneven clamping force to the conveyor belt 10 - the clamping force is greater at the sides of the conveyor belt 10 than at the middle thereof.

This evenly distributed clamping force 190 is an aim of the disclosure. It is advantageous in that a relatively light clamp assembly 100 (still made at least predominantly from aluminium) can impart a strong enough and evenly distributed clamping force 190 to hold or anchor the conveyor belt 10 during service and maintenance or whenever required.

FIGS 10-12 illustrate another feature of the disclosure in the form of an interlocking clamp 210. The clamp 210 has a body constructed of a plurality of parts which connect to and interlock with each other. An advantage of this is that the interlocking clamp 210 can be very light as it is partially hollow. This assembly from parts enables use of less material while still providing sufficient clamping force. It can achieve a structure which may not be achieved from molding or casting a clamp as a single, monolithic unit. The interlocking clamp 210 comprises at least the following parts: two side parts, at least one crosspiece configured to extend between the two side parts, and at least one rear part configured to provide a back piece. More specifically, in this example, the interlocking clamp 210 comprises eight main structural parts (as can best be seen in FIG. 12), namely: a pair of side parts 212 having a C-shaped profile; a top crosspiece 214; a bottom crosspiece 216; a top rear part 220; a bottom rear part 222; and a pair of side rear parts 224.

The parts 212...224 include various lugs and matched sockets, e.g., side lug 240 on the bottom crosspiece 216 which can be accommodated in a complemental aperture 242 at a bottom of the side part 212.

The clamp 210 also includes a plurality (specifically, 10) of mechanical fasteners 230 each in the form of a screw with a hex head for securing or fastening the various parts 212...224 together. Different fastening methods may be practicable.

The side parts 212 may provide much of the structural rigidity of the clamp 210, being able to sustain the clamping force imparted by the clamp 210 via the beams to the conveyor belt 10. Both crosspieces 214, 216 space the side parts 212 fixedly apart but the top crosspiece 214 defines a threaded socket to accommodate the rotatable screw 115 (which defines the displaceable jaw) while the bottom crosspiece 216 has a flat surface which serves as the fixed jaw 119.

The rear parts 220...224 fit together to define a back piece having a hollow rectangular profile (see FIG. 11 ) and are configured to space the side parts 212 fixedly apart at their rear. Each side rear part 224 defines an aperture to accommodate the shackle 120 which may be fastened on one or both sides of the clamp 210.

To decrease weight further, channels or segments of material may be removed, as indicated by recess 244 in an outer face of the side piece 212. This may be done on various faces or at various places on one or more of the parts 212...224. To ensure that the clamp 210 is strong enough while being light, it may be made of a high-grade aluminium material, e.g., 7075 aluminium alloy (AA7075) or some variant thereof.

FIGS 13-14 merely illustrate a slightly different version of the curved beam 250 still having the curved clamping face but having different gripping formations including crisscross grooves, which may provide an enhanced gripping effect. The additional FIGS 13-14 may also serve to illustrate the curvature from different angles.

Finally, FIG. 15 illustrates a clamping assembly 200 comprising the clamps 210 of FIGS 10-12 and the beams 250 of FIGS 13-14. This clamping assembly 200 may be able to provide an evenly distributed clamping force (the diagram of FIG. 8 still applies) while being lighter, even significantly lighter, than any prior art clamp assembly known to the Applicant which can provide comparable and/or evenly distributed clamping force.