AU642476B2 - Joining method and apparatus - Google Patents

Description

JOINING METHOD AND APPARATUS TECHNICAL FIELD This invention relates to a method of and apparatus for joining elements in a manner which provides a laced connection and which, in the case of abutting elements, provides for flexibility at the joint. The invention has particular application to the joining of belts which are used in conveying and power transmission systems and the invention is hereinafter described in the context of

conveyor belt splicing. However, it is to be understood that the invention does have broader application, for example in the joining of two sheet materials which may be similar or different in size and structure and which may be disposed either in overlapping, abutting or non-abutting relationship.

BACKGROUND ART

Conveyor belts are conventionally spliced by using hinged fasteners which are riveted or stapled to abutting ends of the belts and which are interconnected by hinge pins. Alternatively, the splicing is effected by use of so-called lacing elements which are secured to each of the abutting ends of a conveyor belt and which also are

interconnected by hinge pins.

A problem with these fasteners and lacing elements is that they are essentially non-flexible in the longitudinal direction of the belt and, in order to minimise the extent to which they impart undesired rigidity to the belt, the elements are secured as close as possible to the belt ends. However, this results in weakening of the total structure because of a minimum amount of reinforcing warp being present between the rivets or staples and the end of the belt to resist tensile loading forces which tend to draw the fastening elements from the belt ends. Furthermore, the conventional types of fasteners add significantly to the thickness of conveyor belts and they add to the operating noise level of conveyor systems.

DISCLOSURE OF THE INVENTION

The present invention in one of its applications is directed to a method of splicing conveyor belts or power transmission belts in a manner which facilitates flexible jointing and which permits interconnection of the belts at points distant from the adjacent belt ends.

Broadly defined, the present invention provides a method of joining two work pieces and which comprises positioning the work pieces between at least two

spaced-apart substantially parallel rollers which have an axial length at least equal to the length of the join to be made between the work pieces, directing a lacing material around the rollers, and driving the rollers in a manner such that the lacing material is caused to form successive loops around the rollers and to pass through each of the work pieces at least once during each loop. Relative movement of the work pieces and the rollers is effected in the axial direction of the rollers whereby the successive loops of the lacing material are caused to extend around the rollers and make the passes through the work pieces at transversely spaced intervals. Relative movement between the work pieces and the rollers is maintained in the axial direction of the rollers following formation of the last of the loops, whereby the rollers are caused to move progressively from within the loops and successive ones of the loops are progressively released from contact with the rollers, and drive to the rollers is maintained whereby the portions of the successive loops of the lacing material which are released from contact with the rollers are progressively drawn through the length of the join. By first looping the lacing material around the rollers whilst passing it through the work pieces, loops of the lacing material are accumulated on the rollers. In so doing, the full length of lacing can be drawn through the join without binding in the successive points of passage through the work pieces. Thereafter, by continuing to drive the rollers and withdrawing them from the loops, so as to release the successive loops from contact with the rollers, the excess lacing material can be drawn through the work pieces to tighten the loops and complete the lacing

operation.

In some applications of the invention the join length may be shorter than the work pieces are wide. However, it is expected that in most circumstances the join lengths will be equal to the width of the work pieces, in which cases the rollers will have an axial length equal to or greater than the width of the work pieces. This would be the case when the invention is applied to the splicing of conveyor or power transmission belting.

The present invention also provides an apparatus for performing the method as above defined and which comprises at least two spaced-apart substantially parallel rollers which have an axial length at least equal to the length of a join to be made between the two work pieces, and means for supporting the rollers in their spaced-apart relationship. Drive means are provided for imparting drive to the rollers whereby each roller is caused to rotate in a direction which is predetermined by the configuration of a loop to be formed by a lacing material which is fed to the apparatus.

Directing means are provided for directing the lacing material around the rollers during formation of successive ones of the loops. Further means are provided for

supporting the work pieces in a position between the rollers and for effecting relative movement of the work pieces and the rollers in the axial direction of the rollers. Whilst two only spaced-apart rollers may be provided when it is sufficient that the apparatus be used for a simple loop, with the loop having a width equal to the diameter of the rollers, and whilst six or eight rollers may be provided when complicated loop configurations are

required, it is preferred that four only substantially parallel rollers be provided. With this preferred

arrangement the rollers may be driven in a manner such that each loop is caused to follow a generally rectangular path or, with an alternative drive arrangement, to follow a figure-of-eight path. It is this latter arrangement which is considered to be particularly suitable for belt splicing.

The lacing material to be used in the method and apparatus of the invention will be selected according to the nature of the work pieces and the type of join required. It may in some cases comprise a thread of a synthetic plastics material or a fibrous yarn or the like. However, again in the context of belt splicing, the lacing material preferably comprises wire strand or wire rope and is hereinafter referred to generally as a wire cord.

When the work pieces are constituted by relatively thick material, as would normally be so in the case of conveyor or transmission belting, holes will need be

pre-formed in the work pieces to receive the lacing

material. To meet this requirement, the apparatus of the present invention preferably incorporates means for forming an array of holes in each of the work pieces.

The invention will be more fully understood from the following description of a preferred embodiment of an apparatus which has been developed specifically for splicing conveyor belts. The description is provided with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings -

Figure 1 shows a perspective view of a portion of a spliced joint between adjacent ends of a conveyor belt.

Figure 2 shows a sectional elevation view of the spliced conveyor belt as viewed in the direction of section plane 2-2 in Figure 1,

Figure 3 shows a perspective view of a principal portion of the apparatus which is employee for effecting the splicing shown in Figure 1,

Figure 4 shows a plan view of the apparatus as seen in the direction of arrow 4 in Figure 3,

Figure 5 shows, on an enlarged scale, a front elevational view of a portion of the apparatus as seen in the direction of arrow 5 in Figure 3,

Figure 5A shows a sectional elevation view of a guide plate portion of the apparatus as seen in the direction of section plane 5A-5A in Figure 5,

Figures 6A to 6D show, in a diagramatic manner, sequential splicing operations of the apparatus which is illustrated in Figures 3 to 5, and

Figure 7 shows a detailed perspective view of a portion of the apparatus which is employed for channelling a wire cord in alternative directions during formation of each loop in a splicing operation.

MODE FOR CARRYING OUT THE INVENTION As shown in Figures 1 and 2 of the drawings, the adjacent ends 10 and 11 of a reinforced synthetic rubber or synthetic plastics material conveyor belt are spliced together by a wire cord 12. The cord is passed through holes 13 which are formed as an array (i.e., in a straight line) in each of the belt ends and the cord is looped in a figure-of-eight configuration. The rollers 20 and 23 project outwardly from the upper housing component 24A and the rollers 21 and 22 project outwardly from the lower housing component.

Thus, a portion of the cord 12 passes out from the bottom of one of the belt ends 10, extends upwardly through space 14 between the adjacent belt ends, enters a hole in the top of the belt end 11 and exits from the same hole at the bottom of the belt end 11. Thereafter, the cord 12 passes upwardly through the space 14, crossing ahead of the previous pass made through the space, and enters one of the holes 13 in the top of the belt end 10. This looping continues uninterrupted across the full width of the belt and the two (starting and finishing) ends of the wire cord 12 are clamped into their respective holes 13 by clamping screws 15 which are recessed into the sides of the belt ends.

The spacing s between the holes 13 and the distance d that the arrays are set back from the respective belt ends will be a function of the belt size and the power

transmission or load requirements of the belt. However, the distance d would normally be not less than 50mm and the holes might typically be spaced-apart by a distance s equal to 5mm. The gap 14 between the belt ends might typically be in the order of 10mm.

The apparatus which is used to effect the

figure-of-eight splicing is illustrated in a partially schematic manner in Figures 3 to 7 and it comprises four rollers 20-23 which are centred on the corners of a

rectangle. The rollers project outwardly from a housing 24 with their axes of rotation being parallel to one another. The rollers have an axial length slightly greater than the width w of the belt portions 10 and 11, and the rollers are supported adjacent their outer ends by an outrigger bearing plate 24C. The housing 24 is constructed with upper and lower housing components 24A and 24B separated by a horizontal gap 25, and the two components 24A and 24B are joined by a central web 26. The web 26 has a width equal to or less than that of the space 14 between the belt ends 10 and 11.

An electric motor 27 is mounted to the housing 24 and is coupled to each of the rollers 20-23 by way of gearing (not shown) within the housing. The gearing is arranged such that the rollers are caused to rotate in the directions of the arrows shown in Figure 5. That is, rollers 20 and 21 are driven in a counter-clockwise direction while rollers 22 and 23 are driven in a clockwise direction.

Two pinch rollers 28 are located adjacent the housing end of each of the driven rollers 20-23 for directing the wire cord 12 around the driven rollers in a manner which is to be hereinafter described. The pinch rollers 28 are freely rotatable about their own axes and they are driven by frictional engagement with the wire cord 12 when it is pinched between the pinch rollers 28 and the associated driven rollers 20-23.

A guide plate 29, which is formed around its internal margin with a groove 29A, is mounted to each of the housing components 24A and 24B. The guide plate is provided to channel the wire cord 12 around the driven rollers 20 to 23 at points between the pinch rollers 28 and to direct the wire cord toward and through the belt portions 10 and 11.

As shown schematically in Figure 6 of the drawings, the wire cord 12 is carried by a spool 30 which may be removably mounted to the apparatus by way of a structural support member (not shown).

The housing 24 has laterally extending arms 31 which are carried by support rails 32, and a cam driven

pawl-ratchet mechanism 33A is located within one of the arms 31. The pawl-ratchet mechanism 33A engages with a rack 33B which is mounted to one of the support rails 32. Incremental drive is imparted to the housing 24 by engagement between the pawl-ratchet mechanism and the rack, and the housing is thereby caused to move incrementally between the positions shown in Figures 6A and 6D. The housing 24 is driven a distance equal to approximately double the length of the rollers 20-23 in order to effect a complete splicing operation. This will be described in more detail later in the specification.

The belt ends 10 and 11 are carried by a supporting structure 32A, and they are clamped or otherwise held in a fixed position in alignment with the slot 25 between the two components 24A and 24B of the housing 24.

In operation of the apparatus described thus far, the housing 24 and associated components, including the rollers 20-23, are caused to move relative to the belt ends 10 and 11. The movement is in the axial direction of the driven rollers and this movement is effected by way of the

pawl-rack drive connection between the support arms 31 and the rails 32. Thus, the housing 24 is moved incrementally relative to the belt ends 10 and 11, with each incremental distance being equal to the lateral spacing s between the holes 13 in the belt ends.

A belt levelling mechanism 34 is connected to the lower housing portion 24B and comprises a central spacer plate 35 and upper and lower roller arrangements 36, the upper one only of which is shown in Figure 3. During operation of the apparatus, the belt portions 10 and 11 are positioned between the upper and lower roller arrangements 36 and the belt portions are thereby positioned relative to the apparatus in the proximity of two electrically driven drills 37.

The drills 37 are mounted to the housing portion 24A by way of a reciprocating plate 38, the plate 38 being carried in slides 39 and being engaged by a lead screw 40. The lead screw is driven to rotate firstly in one direction and then in the opposition direction (i.e., to oscillate in its direction of rotation) so that the plate 38 is caused to move downwardly and upwardly in a reciprocating manner.

Drive for the lead screw 40 is derived from an electric motor (not shown) which is incorporated in the reciprocating plate 38, and the drills 37 are energised constantly.

The reciprocating plate 38 is moved downwardly during the dwell period between each incremental movement of the housing. Thus, successive pairs of countersunk holes 13 are drilled as the apparatus increments across the width of the belt portions 10 and 11, and a plurality of holes

(approximately twenty in number) is drilled prior to the commencement of the splicing operation. The depth of countersinking is determined by the extent of downward movement of the plate 38 and by the position of the belt portions between the upper and lower roller arrangements 36 of the belt levelling mechanism 34.

When performing the splicing operation, as shown in Figures 6A-6D the belt ends 10 and 11 are located and clamped in position on the supporting structure and the housing 24 (together with the driven rollers) is moved in the axial direction of the rollers. The housing is moved initially in incremental steps from the position shown in Figure 5A to that in Figure 5C and, whilst this movement is being effected, the wire cord 12 is directed to and around the driven rollers 20-23. This results in the wire cord forming repetitive figure-of-eight loops around the rollers and, in the course of so doing, the wire cord is passed through one hole 13 in each of the belt ends 10 and 11 during each complete loop.

Successive figure-of-eight loops are thereby caused to extend around the driven rollers 20-23 and to make the passes through the successive holes 13. The number of loops corresponds with the number of paired holes 13 in the arrays at the ends of the belts 10 and 11. The leading or starting end of the wire cord 12 is thus passed successively through every hole 13, so that the leading end of the cord is fed throughout the full length of the spliced joint. This is facilitated by driving each loop not only through the holes in the belt ends but also around the driven rollers 20 to 23. Thus, the first formed loop is driven to move serially through all of the holes 13 in the belt ends and the subsequently formed loops build up behind and follow the first loop.

At the commencement of the splicing operation, as is best seen from Figure 5 of the drawings, the leading end of the wire cord 12 is fed into the channel 29A between the guide plate 29 and the first driven roller 20. The leading end of the wire cord 12 is then driven through the guide plate channel 29A by the driven roller 20 and is driven downwardly through a first of the holes 13 in the belt portion 10. Thereafter, the leading end of the wire cord 12 is directed through the channel 29A between the lower guide plate 29 and the driven roller 21 and, having passed around the roller 21, the leading end of the wire cord is directed upwardly through grooves 41 and 42 in two relatively

inverted cone-shaped cord directing elements 43 and 44.

These elements are described in greater detail below with reference to Figures 5 and 7 of the drawings.

After passing upwardly through the grooves 41 and 42 in the cord directing elements 43 and 44, the leading end of the wire cord 12 is directed into the channel 29A between the upper plate 29 and the roller 23, and the leading end of the cord is carried around the roller 23. The leading end of the cord 12 is moved continuously around the rollers and through the channel 29A as a consequence of drive being imparted continuously to the rollers 20 to 23 and, further, as a consequence of the leading end of the cord passing between the driven rollers 20 to 23 and the pinch rollers 28,

Having been conveyed between the driven roller 23 and the associated groove portion 29A, the leading end of the wire cord 12 is directed downwardly to enter the groove 29A between the lower guide plate 29 and the roller 22. The leading end of the wire cord is thereafter directed upwardly through the grooves 41 and 42 in the two cone-shaped cord directing elements 43 and 44, such elements having been rotated to a new position to permit such guidance of the leading end of the wire cord, and the leading end of the wire cord is then directed around the first mentioned of the rollers 20 to complete the first figure-of-eight loop. This feeding process is repeated so that the successive loops are extended around the rollers, although it is only the leading end of the wire cord which actually passes through the channel 29A in the guide plates.

After passing through successive ones of the holes 13 in the belt end 10, the presence of the leading end of the wire cord 12 is detected by a proximity detector 46. This causes energisation of an electrical circuit which effects rotation of both of the cone-shaped cord directing elements 43 and 44 in the directions indicated by the arrows in

Figure 7 of the drawings. That is, the grooves 41 and 42 in the cone-shaped elements 43 and 44 are rotated from the positions shown in Figure 7 to the positions shown in Figure 5, so that the leading end of the wire cord 12 may be directed diagonally upwardly from the roller 21 to the roller 23.

Similarly, after passing around the roller 23 and down through successive ones of the holes 13 in the belt end 11, the presence of the leading end of the wire cord 12 is detected by a further proximity detector 47. This again causes energisation of the electrical circuit (not shown) which effects rotation of both of the cone-shaped elements 43 and 44 in the reverse direction, so that the grooves 41 and 42 in the cone-shaped elements are rotated from the positions shown in Figure 5 to the positions shown in Figure 7. With the grooves 41 and 42 so positioned, the leading end of the wire cord 12 may be directed diagonally upwardly from the roller 22 to the roller 20. During the period when the cone-shaped directing elements 42 and 43 are counter rotating, the two grooves 41 and 42 align for a brief instant in time and face outwardly in the axial direction of the rollers 20 to 23, so that the portion of the wire cord which previously was directed through the grooves is released from confinement in the grooves. When the previously confined portion of the wire cord has been released from within the grooves, the

cone-shaped elements continue to rotate to the next

cord-receiving position and this mechanism ensures that a succeeding portion of the wire cord crosses ahead of a preceding portion of the wire cord.

A circumferentially extending groove 45 is provided in the upper cone-shaped directing element 44, and a further proximity detector 48 is located adjacent the groove 45 so that the presence of a cord portion in the groove 42 may be detected. When such detection occurs the pawl-ratchet mechanism 33A is energised so as to advance the apparatus incrementally relative to the belt ends 10 and 11. Thus, the apparatus is incremented just as the leading end of the wire cord is directed over the driven roller 20, so that the leading end of the wire cord 12 is directed through

successive holes 13 in the belt end 10 and, thus, through successive holes in the belt end 11.

Energisation of the lead screw 40 and, thus,

operation of the drills 37 occurs immediately after each incrementation of the apparatus.

When the apparatus has reached the condition shown in Figure 6C and every one of the holes 13 in both of the belt ends 10 and 11 has been occupied by a portion of the wire cord 12, and the last of the loops has been formed, drive continues to be applied to the housing 24 so that the driven rollers 20 to 23 are caused to move progressively from within the loops. That is, when moving from the condition shown in Figure 6C to that in shown in Figure 6D, successive ones of the loops are progressively released from contact with the rollers 20 to 23. The leading end of the wire cord 12 is released from the pinch rollers 28 and the guide plate 29 during this part of the splicing operation, but the drive to the driven rollers 20 to 23 is maintained so that the portions of each loop of the wire cord 12 which are released from contact with the rollers are progressively drawn through the spliced joint, and the wire cord 12 is effectively pulled into the condition which is shown in Figures 1 and 2 of the

drawings. Thus, the driven rollers 20 to 23 act as capstans and the leading end of the wire cord may be pulled away from the apparatus either by hand or by a power-driven spool (not shown) which serves to maintain a constant tensile loading in the wire cord whilst a length of the cord which is excess to the requirements of the spliced joint after tightening is being recovered from the joint.

By first looping the wire cord 12 around the rollers 20 to 23 and then, after forming the entire spliced joint, continuing to drive the rollers 20 to 23 whilst releasing the successive loops from contact with the rollers, the full length of lacing can be drawn through the splice without binding in the successive points of passage through the belt ends. The wire which is effectively recovered from the rollers may be discarded or be recovered for future use.

When releasing the successive loops from the rollers 20 to 23 it is important that one loop only be released at a given time and that tension be maintained in the portion of the wire cord 12 that forms the released loop. In some applications of the invention it may be necessary to control this operation by locating a pivotable lever arm or the like (not shown) at the outer end of at least one of the driven rollers 20 to 23 and by actuating such lever arm in a manner such that it permits one only loop to be released at a given time and in a manner such that it maintains tension in the loop whilst the length of the loop is effectively being shortened to the conditions shown in Figures 1 and 2.

Claims (21)

THE CLAIMS

1. A method of joining two work pieces and which comprises the steps of:

(a) positioning the work pieces between at least two spaced-apart substantially parallel rollers which have an axial length at least equal to the length of the join to be made between the work pieces,

(b) directing a lacing material around the rollers and driving the rollers in a manner such that the lacing material is caused to form successive loops around the rollers and to pass through each of the work pieces at least once during each loop,

(c) effecting relative movement of the work pieces and the rollers in the axial direction of the rollers whereby the successive loops of the lacing material are caused to extend around the rollers and make the passes through the work pieces at transversely spaced intervals,

(d) maintaining the relative movement between the work pieces and the rollers in the axial direction of the rollers following formation of the last of the loops, whereby the rollers are caused to move progressively from within the loops and successive ones of the loops are progressively released from contact with the rollers, and

(e) maintaining drive to the rollers whereby the portions of the successive loops of the lacing material which are released from contact with the rollers are

progressively drawn through the length of the join.

2. The method as claimed in Claim 1 wherein the work pieces are positioned horizontally between two pairs of rollers.

3. The method as claimed in Claim 2 wherein the lacing material is directed around the rollers in a manner such that the lacing material forms successive figure-of- eight loops.

4. The method as claimed in any one of Claims 1 to

3 wherein the lacing material comprises wire cord.

5. The method as claimed in any one of Claims 1 to

4 wherein an array of holes is formed in each of the work pieces to receive the lacing material.

6. The method as claimed in any one of Claims 1 to

5 when employed for joining adjacent end portions of a conveyor belt or a power transmission belt.

7. The method of joining two work pieces in the manner substantially as hereinbefore described with

reference to the accompanying drawings.

8. An apparatus for use in joining two work pieces and which comprises:

(a) at least two spaced-apart substantially parallel driven rollers which have an axial length at least equal to the length of the join to be made between the two work pieces,

(b) means for supporting the driven rollers in their spaced-apart relationship,

(c) drive means for imparting drive to the driven rollers whereby each roller is caused to rotate in a

direction which is predetermined by the configuration of a loop to be formed by a lacing material which is fed to the apparatus during operation of the apparatus,

(d) directing means for directing the lacing material around the driven rollers during formation of successive ones of the loops,

(e) means for supporting the work pieces in a position between the rollers, and

(f) means for effecting relative movement of the work pieces and the driven rollers in the axial direction of the rollers.

9. The apparatus as claimed in Claim 8 wherein there are four driven rollers arranged symmetrically in pairs.

10. The apparatus as claimed in Claim 9 wherein the driven rollers are centred on the corners of a rectangle.

11. The apparatus as claimed in Claim 9 or Claim 10 wherein the drive means is arranged to drive horizontally arrayed ones of the driven rollers in counter rotating directions and to drive vertically arrayed ones of the driven rollers in a common direction.

12. The apparatus as claimed in any one of Claims 8 to 11 wherein at least one pinch roller is mounted to the roller support means adjacent each of the driven rollers, each pinch roller being freely rotatable about its own axis and being arranged to be driven by frictional engagement with the lacing material when, in use of the apparatus, the lacing material is pinched between the pinch roller and the associated driven roller.

13. The apparatus as claimed in any one of Claims 8 to 12 wherein at least one guide plate is mounted to the roller support means and is arranged in use of the apparatus to channel a leading end of the lacing material around the driven rollers and to direct the leading end of the lacing material through the work pieces.

14. The apparatus as claimed in any one of Claims 8 to 13 wherein means are provided on the roller support means for pre-forming holes within the work pieces in positions arrayed to receive loops of the lacing material during operation of the apparatus.

15. The apparatus as claimed in any one of Claims 8 to 14 wherein the roller support means is supported upon rails and wherein the means for effecting relative movement of the work pieces and the driven rollers is constituted by a drive mechanism which is operable to effect incremental movement between the roller support means and at least one of the rails.

16. The apparatus as claimed in any one of Claims 9 to 11 wherein a directing mechanism is mounted to the roller support means centrally of the driven rollers, the directing mechanism being arranged in operation of the apparatus to channel the lacing material in a diagonal direction between diagonally disposed ones of the driven rollers.

17. The apparatus as claimed in Claim 16 wherein the directing mechanism is actuatable in use of the

apparatus to channel the leading end of the lacing material alternatingly between two diagonally disposed pairs of the driven rollers.

18. The apparatus as claimed in any one of Claims 8 to 17 wherein the lacing material comprises wire cord.

19. The apparatus as claimed in any one of Claims 8 to 18 wherein the means for supporting the two work pieces including means for clamping the work pieces in spaced-apart relationship.

20. The apparatus as claimed in any one of Claims 8 to 19 wherein a mechanism is provided on at least one of the driven rollers for preventing the release of more than one loop from the end of the roller at any given time.

21. An apparatus for joining two work pieces substantially as shown in the accompanying drawings and substantially as hereinbefore described with reference thereto.