US2475171A - Cloth-cutting machine - Google Patents

Description

July 5, 1949. w. BANGSER ETAL 2,475,171

CLOTH-CUTTING HAGHINE I Filed July 4, 1945 2 sneets sneat 1 INVE TORS w;

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' ATTORNEYS y 1949- w. BANGSER arm. v 2;4 75;171 v I CLOTH-CUTTING ncnrum Filed y 9 5 2 sums-sum 2 ATTORNEYS Patented July 5, 1949 UNITED STATES PATENT OFFICE CLOTH-CUTTING MACHINE York Application July 4, 1945, Serial No. 603,152

1 Claim. 1

This invention relates to cloth-cutting machines of the reciprocating knife type and particularly to means for sharpening the knives of such machines.

In Patent No. 2,156,798, covering an invention made by one of the present joint inventors, there is illustrated and described a motor-driven clothcutting machine of the reciprocating knife type provided with a pair of rotary grindstones for periodically sharpening the knife. While the machine is being used for cutting cloth, the stones, carried on swinging arms, are held forward of the knife guard, well above and beyond the upper end of the knife. When the time for sharpening comes, the guard and presser foot are lowered, a friction drive Wheel is swung into contact with the fly-wheel of the motor, whereupon, through appropriate mechanism the stones, rotating on vertical axes, are swung on their arms around the guard and into grinding contact with the knife, one on either side. The stones, still rotating (outwardly with respect to the cutting edge), are moved down the length of the reciprocating knife and up again, whereupon they are swung out by the same means that swung them in, and into inoperative position, thus completing the grinding cycle.

It has been found that the rotative speed at which the grindstones are driven is an important factor affecting the quality of the cutting done and must be varied with the character of the goods being out if the most satisfactory results are to be achieved. Generally speaking, soft fabrics and those woven or knitted of low melting point synthetics should be cut with a knife sharpened by means of slowly rotating stones, while best results in cutting hard, tough fabrics are obtained when the knife is sharpened by rapidly rotating stones. A cloth cutter who must, in the course of his work, cut cloths of all degrees of hardness and fusibility, might provide himself with an array of machines, each with stones driven at a speed appropriate for goods falling in one category. This, however, would be cumbersome and expensive. It is, therefore, the object of the present invention to provide a gear shift whereby the stones of one machine may be driven at different speeds at different times, so that the same machine may acceptably be used for goods having different cutting characteristics.

In the accompanying drawings We have illustrated a preferred embodiment of our invention, although other means for accomplishing the same ends could doubtless be devised within its purview, as defined by our claims.

In these drawings Figure lis a side elevation of a cloth-cutting machine of the reciprocating knife type,

Figure 2 is an end elevation of part of the machine of Figure 1,

Figure 3 is a transverse section, on an enlarged scale, taken along-line 3-3 of Figure 1,

Figure 4 is a vertical section on an enlarged scale taken along line 44 of Figure 1 and showing the grindstone drive gears and shift mechanism in some detail, the gears being meshed for low speed,

Figure 5 is a detail of some of the grindstone drive gears and shift, the gears being meshed for high speed,

Figure 6 is a transverse section taken alo line B6 of Figure 4, and

Figure 7 shows a modification having more convenient means for actuating the release button of the shift lever.

Except for the shift mechanism of the present invention, the cams for swinging the stones, and the means for throwing the friction drive wheel into engagement with the fly wheel, the machine illustrated in these drawings is essentially the one illustrated in Figures 1 through 9 of Patent No. 2,156,798, to which the reader should refer for a more detailed account of the machine and its operation, a knowledge of which will be generally presumed in the description to follow.

The cloth-cutting machine illustrated in these drawings comprises the usual base I on which is mounted a standard 2 carrying a motor 3. A knife 4 is mounted in a vertical slot in the forward edge of the standard and reciprocated by means of a cross-head 5, a pitman 6 and a crank I, mounted on the fly wheel 8 of the motor. A guard 9 carrying a presser foot I l is mounted for vertical adjustment immediately in front of the knife. Mounted on the front of the motor housing is a fixed grinder frame l2 having vertical guideways 13 in which is slidably mounted a grinder slide l4 closed at its lower end by a block l5 extending inward. Journalled in the inner end of this block are two vertical spindles l6 supporting at their lower ends arms I! carrying studs 18 on which grindstones l9 are journalled. The upper ends of the spindles l6 terminate in pilot rods 2| enveloped by and fixed to cams 22 adapted to engage fixed cams 23 carried by the fixed grinder frame [2 to swing the stones I9 into and out of grinding contact with the knife as the grinder slide is traversed substantially as described in Patent No. 2,156,798. Coil springs 24 encircle the cams 22, being anchored at one end to the block l5 and at the other to one of the cams 22, and tend to swing the stones into grinding contact with the knife as shown in Figure 3. As the traverse of the stones during the grinding cycle is the same as that described in Patent No. 2,156,798, and forms no part of the present invention we shall not describe it, but shall proceed now to describe the mechanism for rotating the stones, including the gear shift or speed change mechanism which is the subject of the present invention.

The shaft 25, which carries the friction drive wheel 26, is journalled in a sleeve 21 pivoted at 28 to the fixed grinder frame l2 for movement in a vertical plane and is also journalled at the end remote from the drive wheel in a block 29 likewise pivoted at 28 to the frame. A trigger arm 30 is pivoted at 3| to the lower face of block 29 for movement in a horizontal plane. During the cloth-cutting operations of the machine the trigger arm 39 is held in a horizontal position parallel with the grinder slide l4 by means of a bracket 32 projecting from the forward face of the slide and in this position, as illustrated in Figure 2, the friction drive wheel 26 is held out of contact with the fiy wheel 8. A coil spring 33, supported at one end upon a bracket 34, which extends laterally from the fixed grinder frame l2, and engaging the pivoted block 29 at its other end, tends to swing the block clockwise about the pivot 28 and to hold the friction drive wheel into driving engagement with the fly wheel 8. As long, however, as the trigger arm 35 is held in horizontal position by the bracket 32; the

spring 33 is held under compression and cannot act to swing the friction drive wheel into driving position. In order to initiate the grinding cycle, the operator seizes the trigger arm and swings it forward about its pivot 3| against the compression of a spring 35 which normally holds the trigger parallel to the grinder head I4. When the trigger has cleared the bracket 32, the spring 33 is free to act and does act to swing the friction drive wheel into engagement with the fly wheel. At the same time a cam 38 depending from the trigger arm 30 withdraws a slide, lock 36 from an opening 31 in the grinder slide I4 and thus frees the slide for the grinding traverse. As neither the trigger nor the slide lock form a part of the present invention, we shall not describe them further.

We shall now describe the gear trains which rotate the grindstones. At the end of the shaft 25 remote from the friction drive wheel 26 there is fixed a pinion 39 which meshes with a gear 4| coaxial with a pinion 42 meshing with a gear 43 which, in turn, drives a pinion 44 meshing with a gear 45 integral with a bevelled pinion 45 which drives a second bevelled pinion 41 through which passes a vertical square drive shaft 48 journalled in the grinder slide 4. Fixed to the lower end of the square shaft 48 and just below the lower face of the block |5 is a gear 49 which meshes with a pinion 5| coaxial with the spindle l6,

which pinion in turn meshes with a gear 52 carried by one of the grindstones l9. A similar gear train rotates the other grindstone through the intermediary of an idler 53 mounted on the lower face of the block I5. When friction drive wheel 25 is swung into engagement with the rotating fly-wheel 8 of the motor, the gear trains described above are set into operation to rotate the grindstones I9. The gears 39 through 41 are mounted upon the fixed grinder frame 12, whereas the gears 49 through 52 and 53 are carried by the grinder slide l4 and move with it. The square shaft 48 which makes a sliding engagement with the bevelled pinion 41 and extends the entire length of the grinder slide l4, drives the second gear train throughout the grinding traverse and in all positions of the rinder slide.

In order to vary the speed of rotation of the grindstones, we have provided a gear shift mechanism which we shall now describe. The pinion 44 is rotatably mounted on a spindle 54 carried by a link 55 mounted for limited oscillation about a spindle 56 on which the combination spur and bevelled gears 45, 46 are journalled. The limits of oscillation of the link 55 are determined by an arcuate slot 51 in a plate 58 fixed to the grinder frame l2. When the spindle 54 is at the upper end of the slot 51, as shown in Figure 4, the pinion 44 meshes with the gear 43 to drive the stones, as previously described. This is the low speed position. When the link 55 is swung so that the spindle 54 lies at the lower end of the slot 5'|, the pinion 44 meshes with a pinion 55 fixed to and coaxial with a gear 6| which meshes with and is driven by gear 4|. When the gears are in this position, the square shaft 48 is driven from the friction drive wheel 26 through the following gear train: 39, 4|, 6|, 59, 44, 45, 46 and 4'5. This is the high speed position. The pinion 441 is always in mesh with and drives gear 45. When pinion 44 meshes with gear 43, the gear 5| is idling.

The pinion 44 is shifted from one position to the other by the following mechanism: A gear shift lever 62 is pivotally connected at its inner end to spindle 54, which carries the pinion 44, so that the operator, by seizing the knurled end of the shift lever and pulling it upwardly and outwardly from the position shown in Figure 4, moves the spindle 54 down the slot 5! until pinion 44 meshes with pinion 59. To shift gears from high to low speeds, this movement is reversed. In order to prevent accidental shifting of the gears or disengagement of the pinion 44 from either of its driving connections, we provide the shift lever with a dumbbell-shaped slot 63, the enlarged ends of which are engaged in either extreme position by the head 64 of a latch, the shank 65 of which extends through the plate 58 and terminates in a spring-pressed release button E36. To free the lever 62 the operator presses the release button 66 to disenage the head 64 from whichever end of the slot 63 it happens to be in; the operator can then slide the lever to the other position, the shank 65 of the release button sliding through the narrow connecting passage of the dumbbell slot until the other enlarged end is reached, whereupon the spring 61 snaps the head 64 into latching position.

In Figure '7 we have illustrated a modification of the form shown in Figure 6 by means of which operation of the release button is more easily effected. As shown in this figure, the plate 58 is extended to form a finger grip 68, and a corresponding finger grip 69 is pivoted at 1| to the inner end of plate 58 and engages the release button at l2. Thus the operator by pressing the finger grips 68 and 69 between thumb and forefinger effects disengagement 'of the head 64 permitting operation of the gear shift lever, as previously explained.

We claim:

In a cloth-cutting machine of the reciprocating knife type, the combination of stones for sharpening the knife, two driving gears rotating at different speeds, a driven gear, a train of gears including the driven gear for rotating the stones, a movable gear meshing with the driven gear and meshable with either driving gear, a spindle on which the movable gear is mounted, a fixed plate having an arouate slot concentric with the driven gear into which slot the spindle extends, a shift lever pivotally connected to the spindle, a dumbbell slot in the shift lever, a latch on the fixed plate comprising a head of a size to fit snugly either enlarged end of the dumbbell slot and a shank of a size to pass along the connecting passage, and a release button for disengaging the head of the latch from shift lever to permit shifting of the movable gear from one driving gear 15 to the other.

WILLIAM BANGSER. VICTOR L. NICHOLS.

REFERENCES CITED The following referemces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 138,456 Walty Apr. 29, 1873 752,223 Hisey Feb. 16, 1904 1,173,983 Perlman Feb. 29, 1916 1,250,880 Hoddinott Dec. 18, 1917 1,268,373 Maimin et a1 June 4, 1918 1,434,130 Lloyd Oct. 31, 1922 2,156,798 Bangser May 2, 1939

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