US2908008A - Belt-fastening machines - Google Patents

Description

Ce t. 13, 1959 J. J. POTTER 2,908,008

- BELT-FASTENING MACHINES Filed June 9, 1958 3 Sheets-Sheet 1 2O /4 HHHHHHHHHHHHHHHHH F/GJ. L L25 Attorneys Oct. 13, 1959 J. J. POTTER 2,908,008

\ BELT-FASTENING MACHINES Filed June 9, 195a s Shets-Sheet 2 Attorney 5 Oct. 13, 1959 J. J. POTTER 2,908,008

I BELT-FASTENING MACHINES Filed June 9, 1958 3 Sheets-Sheet 3 a n ,& 4125,7

Attorney 5 United States Patent 2,908,008 BELT-FASTENING MACHINES John J. Potter, Sheflield, England, assignor to Hayden- Nilos Limited, Sheflie'ld, England Application June 9, 1958, Serial No. 740,734

Claims priority, application Great Britain June 29, 1957 Claims. (Cl. 1-49.4)

This invention relates to belt-fastening machines, particularly for conveyor belts, of the type in which a jaw unit is moved transversely of the machine after each closing of the jaws to insert fastening hooks, singly or in groups, across the end of a belt that is held in appropriate position in relation to the path of the jaw unit between a fixed clamping bar extending transversely of the machine and a movable transverse clamping bar.

The object of the invention is to provide a clamping device in which the movable clamping bar may be readily brought into and out of clamping relation with respect to the fixed clamping bar, and will remain positively in clamping relation to a belt interposed between it and the fixed clamping bar. A further object is to provide a clamping device in which the movable clamping bar will remain positively in clamping relation to a belt of any thickness in a range of thicknesses within the hook-inserting capacity of the machine.

According to the present invention, in a belt-fastening machine comprising side frames, a jaw unit, guide means for the jaw unit extending transversely between the side frames, and a belt-clamping device having a fixed clamping bar extending transversely between the side frames and a transverse clamping bar movable into and out of clamping relation with respect to the fixed bar, the beltclamping device includes at each side of the machine a crank pin rotatable with respect to the fixed bar and adapted to apply clamping pressure to the movable bar through aspiing, the crank pin being movable to a self-locking position to apply the pressure, and the spring providing accommodation for the pressure to be applied to belts of different thickness.

The crank pin may be operated by or carried by a lever rotatable about an axis fixed with respect to the fixed clamping bar, the pin being rotatable with the lever about the axis between positions that are nearer and farther from the fixed bar by the full throw of the pin, at least the nearer of which positions is a dead-centre position in a perpendicular from the movable bar through the axis of rotation of the lever. Thus, a connecting rod with a shoulder may be pivoted on the crank pin and provide a stem passing through a clear ance hole in the movable bar, the stem carrying a stop collar beyond the hole, and a compression spring being mounted to bear between the shoulder and the movable bar. The connecting rod rocks about the point of engagement of the stem with the clearance hole as the crank pin moves between its positions nearer and farther from the fixed bar, and the spring yields to diiferent thicknesses of belt as the pin moves into its nearer position.

Again, a connecting rod or link pivoted at one end to the crank pin may be pivoted at its other end to a pin 2,908,008 Patented Oct. 13, 1959 on a slider movable within limits with respect to the movable bar with a compression spring interposed between a shoulder on the slider and an abutment surface carried by the movable bar. In this case also, the spring yields to different thicknesses of belt when the crank pin is brought into its nearer position to the fixed bar.

Belt-clamping devices with the two forms of crank and spring mechanism outlined above will now be described in greater detail with reference to the accompanying drawings, in which Figure l is a side elevation of one form of complete belt-fastening machine;

Figure 2 is a plan of the machine;

Figure 3 is an elevation taken from the right-hand end of Figure 1, which the jaw mechanism omitted for the sake of showing the clamping device greater clarity;

Figure 4 is a part-sectional view, to a larger scale, of the left-hand side of Figure 3;

Figure 5 corresponds to Figure 4, but shows a different operative position;

Figure 6 is a section on the line VIVI of Figure 5;

and

Figures 7 to 9 are views, corresponding to Figures 4 to 6, of a second form of clamping device.

In Figures 1 to 3, side frames are formed largely of metal tube, providing upper and lower rails 1, 2, connected by a curved rear end 3, the forward ends 4 of the lower rails 2 curving upwardly, so that the lower rails form skids for easy movement of the machine. Upright plates 5, 6 are welded between the rails 1, 2. The rear ends 3 are connected by welding to a tubular rear tie 7, and the front ends of the rails 1 are connected by welding to a front tie 8.

A round bar 9 between the plates 5 has ratchet teeth 10 to be engaged by a pawl 11 of a jaw unit 12 each time an operating handle 13 moves towards its rear position, as shown in Figures 1 and 2. This moves the jaw unit progressively along the bar 9 and a comb bar 14, slots 15 in which support a row of books 16 (Figure 1) between the jaws 17 of the jaw unit. Operation of the handle 13 closes the jaws 17 on to the hooks 16 and presses the latter into the end portion of a belt 18 (Figures 5 and 6) held between a fixed lower clamping bar 19 of T-section welded between the parts4 of the frame, and an upper movable clamping bar 20 of inverted channel section, the clamping serving to keep the edge of the end of the belt 18 against the face of the comb bar 14 inside the open hooks 16.

The ends of the movable bar 20 are guided vertically in sheet metal standards 21 welded to the upper rails 1 of the side frames and to the front tie 9. Through a clearance hole 22 at each end fits a stem portion 23 of a connecting rod 24 with a shoulder washer 25 below which bears a compression spring 26, the lower end of which bears on the top of the bar 20. Below the hole 22, the stem 23 carries a stop collar 27. The connecting rod 24 is pivoted on a crank pin 28 extending between side cheeks 29 formed by a notch 30 in the end of a clamping lever 31. Two pivot pins 32, in line with each other, are inserted through the sides 33 of the standard 21 to fit holes 34 in the cheeks 29.

With the lever 31 swung about the pins 32 to a position inside the side frame (Figure 4), the'crank pin 28 occupies a position directly above the pins 32, and the connecting rod 24 is lifted by the full throw of the pin 28. The stop collar 27 thus lifts the movable bar 20 3 to its farthest distance from the fixed bar 19, thus permitting the insertion of any thickness of belt 18 within the capacity of the machine. (Actually, the lever 31 may be swung (see the broken lines 31A) beyond the position shown in Figure 4, the limit being reached when the edges 35 of the cheeks 29 meet the top of the washer 25.)

After a belt 18 has been laid over the fixed bar 1%, with its edge against the comb bar 14, the lever 31 is swung over the top of the standard 21, thus bringing the crank pin to its nearest position with respect to {he fixer. bar 19. Bevelled edges 36 (Figure 6) of the movable bar 2t) engage the top surface of the belt firmly within the width of the bar 19 and are pressed to the belt by the compression of the spring 26 imposed by the shoulder washer 25 as the latter is depressed by the crank pin reaching its nearest position with respect to the bar 1'9. The stem 23 pivots with respect to the hole 22 as the pin 28 swings from its upper position to its lower. in that lower position, it is in a perpendicular from the bar Zti through the axes of the pivot pins 32; in other words, it occupies a dead-centre position to maintain the spring 26 compressed. In point of fact, the pin 23 can move slightly beyond this dead-centre position, since the lever 31 can move slightly below the horizontal until it meets a stop 37 on the standard 21 (Figure se the broken lines 31B). This ensures that the spring 2 is locked in compressed condition.

if the belt 13 is thick, the spring 26 is compressed to a greater amount than if the belt is thin, the spring having a rating high enough to ensure that sufiicient pressure is exerted by the bevelled edges 3-6 of the movable bar 2t} to grip firmly the thinnest belt inserted in the machine, the greater compression of the spring with thicker belts resulting in the application of greater pressure to those belts.

Since the levers 31 are swung outside the side frames to apply clamping pressure to the ends of the bar 29, the inoperative position of the levers (Figure 4) brings them inside the side frames and provides for greater compactness in the transporting of the machine.

In Figures 7 to 9, the movable bar 2t carries at each end a spring housing 33 slidable vertically in the guide standard 21 secured to the rail 1 of the side frame. The upper end of the housing 38 has an inwardly opening channel 39 to receive a slider ttl carrying a pin 41 that projects into closed vertical slots 42 in the sides 43 of the channel 3h. A blind bore 44 continuing the channel 39 contains a compression spring 26 that bears on the underside of a shoulder 45 on the slider 40, the end of the bore constituting an abutment surface for the other end of the spring. A lever 31 is carried by the guide standard 21 on pivots 32, a crank pin 28 bridging a notch 30 in the lever and a connecting rod or link 46 is pivoted to the crank pin 28 and the slider pin 41.

The top of the standard 21 is cut away to allow the lever 31 to be swung outwardly to a horizontal position (Figure 7) when it meets a stop 37 and the crank pin is in its uppermost position, i.c., farthest from the fixed bar 19, so that the slider pin 41 is drawn to the top of its slots 42 and the movable bar 21) is fully raised for the insertion of the end of a belt 18. When the lever 31 is swung inwardly (Figure 8), the crank pin 20 is brought to its lowest position, the slider pin 41 being forced towards the bottom of its slots 42, and urging the housing 33 and the movable bar 26 down through the spring 26 until contact is made with the inserted belt, after which the final movement of the slider 40 serves to compress the spring to produce the clamping pressure, which reaches its full amount at the lower dead-centre position reached when the lever 31 reaches its innermost position. The base 47 of the notch in the lever 31 is not quite at right-angles to the length of the lever, so that the lever can move below the horizontal (Figure 8) until that edge bears against the side of the connecting link 46, when the crank pin 28 is slightly beyond the lower dead-centre position. This makes additionally certain that the pressure on the belt is automatically maintained, and can only be released by reverse rotation of the levers 31 at each end of the clamping device, whatever the thickness of the belt.

Considerable mechanical advantage is readily available from relatively short levers 31, because the full throw of the crank pins 28 need be quite small to provide the clamping movement of the movable bar 20. Thus, the levers may be about 6" long, giving a 12:1 advantage with a crank radius of /2" required for a throw of l, to lift the bar 20 by that amount away from the bar 19. Whatever the thickness of the belt 18, the same rotation of the levers 31 to bring the crank pins 28 to their lower dead-centre positions serves to grip the belt and ensure that the grip is maintained by self-locking action. The only difference is that a greater effort must be applied to the levers when a thicker belt is to be clamped.

What I claim is:

1. A belt-fastening machine comprising side frames, a jaw unit, guide means for the jaw unit extending transversely between the side frames, and a belt-clamping device having a fixed clamping bar extending transversely between the side frames, guides near each end of the fixed bar, a transverse clamping bar movable in the guides towards and away from the fixed bar, and, at each guide, a horizontal pivot, a lever mounted on the pivot, a crank pin carried by the lever and movable by swinging of the lever between positions above and below the lever pivot, a connecting rod carried by the crank pin, a compression spring supported by the movable bar, means associated with the connecting rod to bear downwardly on the spring as the crank pin is moved below the lever pivot, and means also associated with the connecting rod to effect an upward urge on the movable bar as the crank pin is moved above the lever pivot.

2. A belt-fastening machine comprising side frames, a jaw unit, guide means for the jaw unit extending transversely between the side frames, and a belt-clamping device having a fixed clamping bar extending transversely between the side frames, guides near each end of the fixed bar, a transverse clamping bar movable in the guides towards and away from the fixed bar, and, at each guide, a horizontal pivot, a lever mounted on the pivot, a crank pin carried by the lever and movable by swinging of the lever between positions above and below the lever pivot, a connecting rod carried by the crank pin, a guide hole in the movable bar through which the rod passes, a collar on the rod beyond the hole, a compression spring supported by the movable bar, above the hole, and a shoulder on the rod to bear on the spring, movement of the crank pin below the lever pivot causing the spring to be compressed on the moving bar.

3. A belt-fastening machine as in claim 2, comprising a stop on each guide positioned to be engaged by the lever pivoted in that guide when the lever is swung to move the crank pin above the lever pivot, the precise position of the stop being such that the lever can bring the crank pin slightly past the position immediately above the lever pivot.

4. A belt-fastening machine comprising side frames, a jaw unit, guide means for the jaw unit extending transversely between the side frames, and a belt-clamping device having a fixed clamping bar extending transversely between the side frames, guides near each end of the fixed bar, a transverse clamping bar movable in the guides towards and away from the fixed bar, and, at each guide, a horizontal pivot, a lever mounted on the pivot, a crank pin carried by the lever and movable by swinging of the lever between positions above and below the lever pivot, a connecting rod carried by the crank pin, in the form of a link, a housing carried by the movable bar, a vertical bore in the housing, a compression spring in the bore, a

slider in the bore bearing as the spring, a pivot pin connecting the slider to the connecting rod, link, and vertical slots in the side of the bore, the pivot pin projecting into the slots and swung to lift the housing when the crank pin is moved above the lever pivot, but free to move down the slots when the slider compresses the spring as the crank pin is moved below the lever pivot.

5. A belt-fastening machine as in claim 4, wherein each lever is formed with cheeks between which the crank pin is carried, the cheeks forming the sides of a notch the base of which is at an angle such that the lever may be swung to bring the crank pin slightly past the position immediately above the lever pivot, as deter- References Cited in the file of this patent UNITED STATES PATENTS 785,432 Perkins Mar. 21, 1905 1,238,964 Vanderveld Sept. 4, 1917 1,630,659 Hacker May 31, 1927 2,167,820 Ziller Aug. 1, 1939 FOREIGN PATENTS 469,963 Great Britain Aug. 6, 1937 776,812 Great Britain June 12, 1957

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