Magnetic tape clamp

Abstract

The magnetic belt clamp is used for clamping the homogeneous conveying belt so as to achieve cutting or clamping. The magnetic tape clamp includes a clamping rod having one or more magnetic switches along its length. When the magnetic switch is in the on position, the magnetic switch attracts the ferromagnetic material in the lower belt aligner to clamp a section of the conveyor belt in the gap between the bottom of the clamping rod and the aligner. The aligner has an alignment structure on the platform that receives the protruding tape feature to register the tape with respect to the guide rail along which the cutting assembly slides to cut across the tape in a precise line. A belt cutter or a magnetic clamp can be easily mounted on the belt splicer to clamp the butt end of the belt to be spliced.

Description

Technical Field

[0001] The present invention relates to a magnetic clamping tool for a flexible plastic conveyor belt. Background Art

[0002] A belt cutter is used to cut flexible plastic conveyor belts such as the Series homogeneous thermoplastic conveyor belts sold by Intralox, LLC, of Harahan, Louisiana, USA, to cut them to a specified length and to make a precise oriented cut at the belt ends before the belt ends are welded together. In a belt with regularly spaced drive teeth, precise cutting is particularly important. If the cutting line is not accurately positioned relative to the teeth, the tooth pitch across the cut end of the weld will not match the regular tooth pitch or pitch of the rest of the belt. A hand-held belt cutter can be used, but the operator must hold the belt when cutting across the width of the belt with the hand-held belt cutter. A jig is used to stabilize the belt for cutting or splicing. The jig only clamps the belt at the side edges of the belt, which typically creates some play in the interior region of the belt. When the cutter passes through undulations in the unclamped interior region of the belt, the cut may deviate from a straight line. Summary of the Invention

[0003] One type of magnetic belt jig includes a clamping bar that extends in length from a first end to a second end, in width from a front side to a rear side, and in thickness from a top to a bottom. One or more magnetic switches are mounted on the clamping bar. A belt aligner is positioned at a gap from the clamping bar and includes a ferromagnetic material and a platform that faces the clamping bar across the gap. Alignment structures in the platform are adapted to receive protruding features on the surface of a plastic conveyor belt received in the gap, thereby registering the conveyor belt. One or more magnetic switches are manually adjustable between a deactivated position that does not magnetically attract the ferromagnetic material in the belt aligner and an activated position that attracts the belt aligner towards the bottom of the clamping bar and clamps the conveyor belt in the gap between the platform of the belt aligner and the clamping bar.

[0004] One type of tape cutter includes a magnetic clamp that includes a clamping bar that extends in length from a first end to a second end, in width from a front side to a rear side, and in thickness from a top side to a bottom side. A series of mounting holes extend along the length of the clamping bar from the top through the thickness of the clamping bar to the bottom. Magnetic switches are each mounted in a separate mounting hole. A tape aligner is positioned a gap away from the clamping bar. The tape aligner includes a ferromagnetic material and a platform that spans the gap and faces the bottom of the clamping bar. Alignment structures in the platform receive protruding features on the surface of a plastic conveyor belt received in the gap, thereby registering the conveyor belt. The magnetic switches are manually adjustable between a deactivated position that does not magnetically attract the ferromagnetic material in the tape aligner and an activated position that attracts the tape aligner toward the bottom of the clamping bar and clamps the conveyor belt in the gap between the platform of the tape aligner and the bottom of the clamping bar. The tape cutter further includes: a guide rail that is fastened to the front side of the clamping bar and extends along the length of the clamping bar; and a cutting assembly that includes a cutting blade and a carriage that is slidably attached to the guide rail to slide along the guide rail and cut through the conveyor belt clamped in the gap along a line outside the gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 is an isometric view of a tape cutter that includes a magnetic tape clamp embodying features of the present invention.

[0006] Figure 2 is Figure 1 an exploded view of the tape cutter of

[0007] Figure 3 is an isometric view of a tape aligner that can be used in the Figure 1 magnetic clamp of

[0008] Figure 4 is an isometric view of two Figure 1 tape cutters of the type shown in

[0009] Figure 5 is Figure 4 a front view of a tape splicer of

[0010] Figure 6 is a top plan view of the clamping bar of a second type of magnetic tape clamp.

[0011] Figure 7 is a top plan view of the clamping bar of an electromagnetic type magnetic tape clamp. DETAILED DESCRIPTION

[0012] Figure 1 and Figure 2Shows a type of cutter with a magnetic fixture embodying the features of the present invention. The cutter 10 includes a magnetic fixture having a clamping bar 12 that extends in length from a first end 14 to a second end 15, in width from a front side 16 to a rear side 17, and in thickness from a top 18 to a bottom 19. A series of mounting holes 20 extend from the top 18 through the thickness of the clamping bar 12 to the bottom 19. In this type, the mounting holes 20 are regularly spaced in a straight line along the length of the clamping bar 12. However, the spacing can also be irregular or staggered. A magnetic switch 22 is installed in each mounting hole 20, such as those sold by Magswitch USA of Superior, Colorado, USA MAGJIG. In this type, fourteen magnetic switches are used, but more or fewer than fourteen can also be used.

[0013] The magnetic switch 22 has two identical radially polarized permanent magnets stacked in a ferromagnetic housing 24. The lower magnet is fixed, while the upper magnet can be rotated by a top knob 26. When the knob 26 is rotated to the off position, the north pole of the upper magnet is directly above the south pole of the lower magnet, and the south pole of the upper magnet is directly above the north pole of the lower magnet. In this arrangement, the magnetic flux is substantially confined within the housing 24 and the two magnets; little or no magnetic flux is generated outside the switch 20, and thus there is no magnetic attraction. When the magnetic switch 20 is rotated to the on position, the north pole of the upper magnet is directly above the north pole of the lower magnet, and the south pole of the upper magnet is directly above the south pole of the lower magnet. In this arrangement, the two magnets effectively act as a single magnet that generates magnetic flux outside the magnetic switch 20 and is capable of attracting nearby external ferromagnetic materials.

[0014] The belt aligner 28 is located below the clamping bar 12. The belt aligner 28 has an alignment structure in the form of an elongated (longitudinal) notch 30 recessed in the top platform 32 of the belt aligner. The elongated notch 30 receives complementary shaped protruding features, such as drive lugs, located in the bottom surface of the flexible conveyor belt 34 to be cut. Belts with different protruding features can be accommodated by different belt aligners that have corresponding complementary alignment structures in the top platform.

[0015] Side rails 36 at the first end 14 and the second end 15 of the clamping bar 12 are fastened to the end of the tape aligner 28 by screws 38. The side rails 36 have vertical raceways 40 in which sliders 42 at the first end 14 and the second end 15 of the clamping bar 12 can slide vertically. When the sliders 42 are in the raceways 40, the clamping bar 12 and the tape aligner 32 are in registration. A handle 48 on top of the clamping bar 12 is used to lift and lower the clamping bar relative to the tape aligner 32. Spring plungers 46 attached to the outside of the side rails 36 have shafts that extend through the side rails to contact the sliders 42, thereby stabilizing the clamping bar 12. When the plungers are retracted, the plungers release the clamping bar 12 so that the clamping bar 12 can be lifted upward along the side rails 36 by the handle 48 on top 18 of the clamping bar.

[0016] A section of the tape 34 is positioned on top of the tape aligner 28 such that the notch 30 of the aligner receives the drive lug of the conveyor belt. The clamping bar 12 is lowered along the side rails 36 to rest on top of the tape 34. The magnetic switch 22 is switched to its on position, creating an attractive force between the switch and the ferromagnetic material in the tape aligner 28. The magnetic attraction tightly clamps and stabilizes the conveyor belt 34 in the gap 50 between the tape aligner 28 and the clamping bar 12. The closely spaced magnetic switches 22 clamp the tape with a pressure that is applied generally uniformly across the entire width of the tape (rather than just acting on the outside of the tape).

[0017] Figure 3 The tape aligner 28 is shown in more detail. A ferromagnetic insert 47 made of carbon steel or other ferromagnetic material is fastened to the aligner 28, in a recess in the platform 32 of the aligner 28, directly spanning Figure 2 the gap 50 of the magnetic switch 22. To reduce weight, the remainder of the tape aligner 28 can be made of aluminum. However, the entire tape aligner can be made of carbon steel or other ferromagnetic material.

[0018] A guide rail 52 is fastened to the front 16 of the clamping bar 12. The guide rail 52 has an upper groove 54 and a lower groove 55. A carriage 56 has upper legs 58 and lower legs 59 that hook into the upper groove 54 and the lower groove 55 of the guide rail 52, respectively. The carriage 56 is part of a cutting assembly 60 that also includes a cutting blade 62 and two blade housing halves 64, 65. The cutting blade 62 is clamped between the two housing halves 64, 65, which are closed around the blade by screws. A thumbscrew 66 in the outer housing half 64 allows the blade to be replaced without tools. The inner housing half 65 is fastened to the carriage 58. A cutter handle 68 is used to manually slide the cutting assembly 60 along the guide rail 52.

[0019] The flange 70 extends below the guide rail 52 to the outside of the front side 16 of the clamping bar 12. The flange 70 terminates at a vertical wall forming a straight edge 72. Since the straight edge 72 is part of the clamping bar 12 and the clamping bar is registered with the tape aligner 28 and thus with the conveyor belt 34 itself, sliding the cutting assembly 60 along the straight edge of the flange 70 causes the tape to be cut along an exact line spanning the width of the tape, the exact line being a known distance from the prominent feature of the tape and located outside the gap 50. Figure 1 and Figure 2 Two cutting assemblies 60 are shown in FIGS. Figure 1 and Figure 2 so that an operator can select the more convenient one. However, the tape cutter 10 can be made to have a single cutting assembly 60.

[0020] In Figure 4 and Figure 5 the tape cutter and splicer 80 shown in FIGS. Figure 4 and Figure 5 use two tape cutters with magnetic clamps as shown in FIGS. Figure 1 and Figure 2 . The tape aligner 28 and the side rails 36 are adapted to be easily mounted on top of the opposing jaws 82 of the tape splicer 84. The jaws 82 are separated by a space 86. The clamping bar 12 is received in the side rails 36. The cutting assemblies 60 located at the front 16 of the clamping bar 12 face each other across the space 86 and can be used to trim the ends of the tape 34. If tape cutting is not required, the cutting assemblies 60 and the guide rail 52 can be omitted. The heating bar 88 can be moved into the space 86 from below. The splicer 84 includes mechanisms that: (a) close the jaws 82 to move the butt ends of the conveyor belt 34 together into contact with the side of the heated heating bar 88 to melt the butt ends; (b) withdraw the butt ends from contact with the side of the heating bar and move the heating bar out of the space 86; (c) move the melted butt ends together in the space to splice them; and (d) release the jaws when cooling of the joined butt ends is complete and splicing is finished.

[0021] When the jaws move towards each other, the springs 90 located at the ends of each of the jaws 82 are compressed. The energy stored in the compressed springs 90 is used to quickly separate the melted tape ends from the side of the heating bar 88 so that the heating bar can be moved out of the space 88 and the melted tape ends move together to form a splice. More details of the splicer mechanism can be found in U.S. Patent No. 9,796,135, issued to Laitram, LLC on October 14, 2017. The disclosure of this patent is incorporated herein by reference.

[0022] Figure 6 and Figure 7 depict alternative forms of the magnetic tape clamp shown in combination with the guide rail and cutting assembly. In Figure 6 ​​​​Among them, multiple magnetic switches 92 are embedded in the clamping bar 94 at spaced positions across the width of the clamping bar. A single on / off lever 96 is coupled to all the magnetic switches 92 through a rack-and-pinion arrangement, a timing belt-gear arrangement, or an equivalent arrangement that allows all the magnetic switches to be switched simultaneously between the on position and the off position. Figure 7 The clamping bar 98 in [reference] does not use a permanent magnet, but instead has a coil 100 wound around its periphery to form an electromagnetic band clamp. The coil may have a ferrite core. Electric power is supplied to the coil through a power cord 102 that terminates in a plug 104 that can be inserted into a power source such as a standard wall socket. Alternatively, electric power may be supplied by a battery. Although not shown in the figure, a conventional switch disposed along the line 102 or a switch integrated within the clamping bar 98 allows the magnetic clamp to be turned on and off. In this way, an electromagnet that can be selectively turned on and off by a switch is a magnetic switch. Instead of Figure 7 a single coil in [reference], multiple electromagnets connected in parallel may be spaced across the clamping bar to generate a magnetic attraction.

[0023] All the magnetic clamps described in the previous specification can be turned on and off and thus have means that can be referred to as magnetic switches that selectively generate a uniform magnetic attraction along the entire length of the clamping bar, thereby applying a substantially uniform clamping force across the entire width of the conveyor belt. Optionally, non-switchable permanent magnets may be installed in the clamping bar to achieve an equivalent uniform clamping force on the conveyor belt.

Claims

1. A magnetic tape clamp, comprising: A clamping bar that extends in length from a first end to a second end, in width from a front side to a rear side, and in thickness from a top to a bottom; One or more magnetic switches mounted in the clamping bar; A tape aligner that is disposed at a gap from the clamping bar and includes: A ferromagnetic material; A platform that spans the gap and faces the clamping bar; An alignment structure located in the platform for receiving a protruding feature on the surface of a plastic conveyor belt received in the gap to register the conveyor belt; Wherein the one or more magnetic switches are manually adjustable between a disconnected position that does not magnetically attract the ferromagnetic material in the tape aligner and a connected position that attracts the tape aligner toward the bottom of the clamping bar and clamps the conveyor belt in the gap between the platform of the tape aligner and the clamping bar.

2. The magnetic tape clamp according to claim 1, wherein, The magnetic tape clamp includes a tape cutter, and the tape cutter includes: A guide rail fastened to the front side of the clamping bar and extending along the length of the clamping bar; and A cutting assembly including a cutting blade and a carriage slidably attached to the guide rail to slide along the guide rail and cut through the conveyor belt clamped in the gap along a line outside the gap.

3. The magnetic tape fixture according to claim 2, wherein, The clamping bar includes a flange protruding from the front side to a straight edge, and the cutting assembly rides along the straight edge to ensure a straight cut through the clamped conveyor belt.

4. The magnetic tape clamp according to claim 2, wherein The cutting assembly includes a handle for manually sliding the carriage along the guide rail to cut the conveyor belt clamped in the gap.

5. The magnetic tape clamp according to claim 2, wherein, The magnetic tape clamp includes a second cutting assembly including a cutting blade and a carriage slidably attached to the guide rail to slide along the guide rail and cut through the conveyor belt clamped in the gap along a line outside the gap.

6. The magnetic tape clamp according to claim 1, wherein The magnetic tape clamp includes a plurality of magnetic switches, and the clamping bar includes a series of mounting holes along the length of the clamping bar that extend from the top through the thickness of the clamping bar to the bottom, and each of the magnetic switches is mounted in a separate mounting hole.

7. The magnetic tape clamp according to claim 1, characterized in that, The magnetic tape clamp includes: Side rails fastened to the tape aligner and having vertical raceways; Wherein the clamping bar has sliders at the first end and the second end that ride in the vertical raceways of the side rails; A handle located on the top of the clamping bar for lifting and lowering the clamping bar.

8. The magnetic tape fixture according to claim 8, wherein The magnetic tape clamp includes a spring plunger that extends through the side rail to stabilize the clamping bar and release the clamping bar to remove the conveyor belt from the gap.

9. The magnetic tape clamp according to claim 1, wherein, When the one or more magnetic switches are in the closed position, the ferromagnetic material causes the tape aligner to be magnetically attracted to the one or more magnetic switches in the clamping bar.

10. The magnetic tape clamp according to claim 1, characterized in that, The alignment structure includes one or more notches recessed in the platform of the tape aligner.

11. The magnetic tape fixture according to claim 1, wherein The one or more magnetic switches include two identical radially polarized permanent magnets stacked in a ferromagnetic housing, wherein one of the two permanent magnets is rotatable between a closed position and an open position, in the closed position, the same magnetic poles of the two permanent magnets are aligned, and in the open position, the opposite magnetic poles of the two permanent magnets are aligned.

12. The magnetic tape fixture according to claim 1, wherein The one or more magnetic switches include one or more coils forming one or more electromagnets.

13. A tape splicer for splicing the butt ends of a conveyor belt, the tape splicer comprising: Two opposing jaws spaced apart across a space; A heating rod movable into the space between the jaws; A mechanism for closing the jaws to move the butt ends into contact with the heating rod to melt the butt ends, for releasing the jaws to move the butt ends out of contact with the heating rod and move the heating rod out of the space, for closing the jaws to move the melted butt ends together to splice the butt ends, and for releasing the jaws when splicing of the butt ends is complete; Two magnetic tape clamps according to claim 1, the two magnetic tape clamps clamping opposite ends of a conveyor belt to be spliced; wherein the front sides of the two clamping bars face each other across the space; and wherein the two tape aligners are mounted on the two opposing jaws.

14. A tape cutter, comprising: A magnetic clamp, the magnetic clamp comprising: A clamping bar extending in length from a first end to a second end, in width from a front side to a rear side, and in thickness from a top to a bottom, and including a series of mounting holes along the length of the clamping bar, the series of mounting holes extending from the top through the thickness of the clamping bar to the bottom; A plurality of magnetic switches, each magnetic switch mounted in a separate mounting hole; A tape aligner disposed below the bottom of the clamping bar across a gap extending along the length of the clamping bar, and including: Ferromagnetic material; A platform facing the bottom of the clamping bar across the gap; An alignment structure located in the platform for receiving a protruding feature on the surface of a plastic conveyor belt received in the gap to register the conveyor belt; wherein the magnetic switch is manually adjusted between an open position and a closed position, the open position not generating a magnetic attraction on the ferromagnetic material in the tape aligner, the closed position attracting the tape aligner towards the bottom of the clamping bar and clamping the conveyor belt in the gap between the platform of the tape aligner and the bottom of the clamping bar; A guide rail, which is fastened to the front side of the clamping bar and extends along the length of the clamping bar; and A cutting assembly, which includes a cutting blade and a carriage, the carriage being slidably attached to the guide rail to slide along the guide rail and cut through the conveyor belt clamped in the gap along a line outside the gap.

Images