US2290015A - Cloth cutting machine - Google Patents

Description

y 9 2- 1.. c. BLESCH 2,290,015

' CLOTH CUTTING MACHINE FiledFe b. 7, 1958 4 Sheet s-Sheet 1 swuwvton I Lads July 14, 1942. L. c. BLESCH CLOTH CUTTING MACHINE Filed Feb. '1: 1938 4 sneaks-sheet 2 I 2M wen-b jails ax/ch11,

y 1942- L. c. BLESCH 2,290,015

CLOTH CUTTING MACHINE Filed Feb. '7, 1938 4 Sheets-Sheet 3 g 8.9 [Ml/Ill t gwua/wrom Lu/s 0.3/esch,

July 14, 1942.

L. C. BLESCH CLOTH CUTTING MACHINE 4 Sheets-Sheet 4 Filed Feb. 7, 1938 mumlllwliil'limnlll Patented July 14, 1942 CLOTH CUTTING MAOHIN E Louis Charles Blesch, Dayton, Ky., assignor to The Wolf Machine Company, Cincinnati, Ohio, a corporation of Ohio Application February 7, 1938,- Serial No. 189,260

30 Claims.

This invention relates to cloth cutting machines, and more particularly to means for sharpening the cutting edges of knives thereof.

The invention is applicable to various types of cutters, such as those having reciprocating or roous other operating mechanisms. Certain objections and problems which these devices did not overcome were the entrance of abrasive grit from the Sharpeners into bearings and moving parts of the cutting mechanism, and into the sharpening device, expense of equipment, complication of machinery in an otherwise simple device, difliculties of getting the sharpening means entirely out of the way when the machine was to be used for cutting purposes, and clogging of the pores of the abrasive material. v

Accordingly, recourse was had, in many instances, to the time-honored practice of handsharpening, with the objections that when an abrasive stone is rubbed on the sides of the knife it is difficult to avoid injury to the standard of a machine of the reciprocating type, or to that portion of the machine frame which houses a cutter of the rotary type, and when using the abrasive stone in a manner which will not injure, the usual result is to apply too short a bevel to the cutting edge of the knife; the longer bevel or edge the knife has, the better it will cut. 1 Other devices, not mechanically driven but forming an attachment for the cutter, held small abrasive blocks or stones to the sides of the knife. The life of these stones, held. in this manner is short, as they soon become choked with grid and metallic particles, rendering them useless.

Portable grinders with a rotary or other driven abrasive stone were tried out, but these were open to many of the objections of hand-grinding and to the objection that in addition to requiring skill in use, they formed no part of the machine and hence were frequently inaccessible.

It is to overcome the foregoing objections, and others which will occur to those skilled in this art, that the present invention was developed, and primary objects of the invention contemplate provision of a sharpening attachment for cloth cutters which is simple in operation, requires no skill in use, forms part of the machine yet is readily positioned out of an operators way, and will not readily become clogged, thus ensuring long life.

Whileit is necessary to-present a fresh abrasive surface constantly to the knife to avoid clogging of the pores of the abrasive, and to ensure abrasive action, as by positively rotating the abrasive block, nevertheless it is desirable to place a check upon the rotary movement and to avoid rapidrotation of the blocks or wheels. Without this check they would rotate with simple movement, and be non-abrasive. Accordingly, another ob ject of the present invention is to provide a, positive drive for the abrasive wheels under control of the operator at all'times, and synchronized with movements of the sharpening device along the knife edge, and to include in such drive a means for maintaining a check upon the wheel rotation. To this end, a planetary gearing is provided which holds the abrasive wheels in check, avoids rapid rotation, and yet positively rotates the Wheels to avoid. a simple movement thereof with the knife.

Still another object contemplates automatically actuating the abrasive wheels without the direct application of power. as from a motor or other positive driving means. In furthering this object it is contemplated that the device will be manually moved lengthwise of the cutter, and that the drive for the wheels will be taken from a fixed rack extending the length of the cutter. It is further contemplated that this rack desirably may be formed as part of the conventional presser foot shaft, thus eliminating an otherwise necessary element.

The knives on reciprocating type cutters usually have, in additiontothevertical cutting edge, a substantially horizontal or tapered edge across the bottom of the knife in a line almost perpendicular to the main cutting edge. It has been found in practice heretofore that, with the exception of hand stones as above referred to, this bottom edge cannotfeasibly be sharpened. Accordingly, another object of this invention is to provide a device by means of which the bottom cutting edge of a reciprocating cloth cutter blade may be sharpenedreadily.

The planetary gearing above mentioned, and its mounting, lend themselves well to this object, and facilitate a desired switching of the abrasive wheels from one position to another at the bottom of the knife, under manual control.

Other objects of the invention include the provision of new and improved means for supporting the grinding or sharpening attachment, as well as a novel, resilient mounting for engaging the gears with the rack, the inclusion of novel means for driving the grinding means, the use of means automatically ensuring contact of the grinding means at the proper points on the side of the knife and for co-action with the respective sides of the knife in order that same may be subjected to selected pressures for sharpening the knife without undue wear during the sharpening operation.

Also, self locking means are provided for positioning the sharpening unit out of the Way when not in use but readily accessible when required, and the individual abrasive elements are positioned and mounted in'a novel manner ensuring quick removal for cleaning or replacement.

To the attainment of the foregoing and other objects, which will appear as the description proceeds, reference may be made to the accompanying drawings, in which:

Fig. l is a side elevation of a cloth cutting machine and sharpening unit embodying the invention, with the attachment shown latched inan inoperative position;

Fig. 2 is a front elevation thereof;

Fig. 3 is a front plan of the sharpening unit;

Fig. 4 is a section taken on line 44 of Fig. 2;

Fig. 5 is a fragmentary elevation showing structural details adjacent the mounting for the sharpener unit;

Fig. 6 is a section partly in elevation taken on the line. 6-6 of Fig. 5;

Fig, '7 is a plan of a modified sharpener unit;

Fig. 8 is an elevation thereof;

Fig. 9 is a plan of a further modification of a sharpener unit,

Fig. 10 is. an. elevation thereof;

Fig. 11 is a front elevation of a still modification of sharpener unit;

Fig. 12 is a side elevation thereof;

Fig. 13 isa plan. View thereof;

Fig. 14 is a fragmentary front elevation of a modified controlfor the sharpener. unit, and

Fig. 15 is a fragmentary side elevation thereof.

Fig. 16 is a front plan of the sharpening unit illustrating a friction drive instead of. the gear drive shown in. Fig. 3.

Referring now more specifically to the drawings in whichlike. reference numerals designate like parts, there will be found. a cloth cutting machine of the reciprocating type, comprising generally a base l5 from which rises a standard I6. Supported by the standard is a motor housing 1, at the front of which isa crank casing l8. A suitable crank and pitman (not shown) operate within the casing I8, being driven by the motor in housing IT. A knife I9 is mounted for vertical reciprocation in the standard I6, said knife being connected at its upper end, as indicated at 20, to the driving mechanism in the casing l8.

A switch box 2| for a switch 22 is secured to the lower part of the frame or motor housing, and projecting rearwardly of the switch box is a handle 23 for manipulatingthe cutter.

The parts thusfar described are conventional, and the present invention is primarily directed to a novel structure for, sharpening cutters such as further the knife I9, and to the mode of operation of such structure A presser foot bar 26 carrying a presser foot 25 is mounted to slide in a guide or bearing 21, located at the front of the crank casing I8, the bar 26 being slightly offset but parallel with respect to the standard l6.

One side of the bar 26 is provided with teeth 28 forming a rack cooperative with a toothed latch 29. The latch 29 is formed with a shank 30 terminating at the opposite end from the latch, in a head 3|. Encircling the shank 39, with one end bearing against the head 3| and the other end bearing against a latch supporting bracket 32 is a spring 33 which yieldingly urges the latch into a latching position engaging the teeth 23. A slidable bar 34 carried by a guide member 35 is positioned to engage the head 3| and, when actuated by an eccentric lever 36, will force the shank 30 and latch 29 outwardly to a position of disengagement from the rack 28. When the bar 34 is retracted by a reverse movement of lever 36, expansion of the spring 33 will again bring the latch 29 into engagement with the rack 23. It will thus be seen that by the use of the latch 29, the presser foot bar may, after it has been raised or lowered, be held at any desired elevation.

Parallel to the bar 26 is a second bar 39, mounted to slide in a guide or bearing 40, this bar 39 being positioned at the opposite side of the knife l9 and standard I 6, from the presser foot bar 26. An adjustable stop 31, preferably mounted in a split bracket 33 is carried by the upper end of the bar 39, and serves, by engagement with the upper surface of the housing for the guides 21 and 49, or by engagement with any suitable abutment properly positioned on the machine, to limit and to determine the lowermost position of said bar 39.

A grinder head designated generally at 4| is secured to the lower end of the bar 39, this head comprising a bracket or plate 42 resiliently pivoted at 43 adjacent the end of bar 39, and an abrasive wheel carrier plate 44 pivotally carried by the bracket 42. A spring 43a secured to the fixed pivot 43 at one end and to a stud on the plate 42 at its other end serves to normally maintain the plate in its operative position. The bracket 42 is provided with a separable handle 45, rigidly secured thereon (Fig. 4) through which extends a pin 46 terminating at its outer end in a knob 41. The pin 46 and knob 41 are freely rotatable with respect to the handle 45, andthe inner-end of the pin functions as a support for the plate 44. To secure pin 46 and plate 44 against relative movement, there is keyed to the end of the pin a bridge 48, the ends of which are notched to engage pins 4949 which extend from the face of the plate 44, being rigidly secured thereto.

The head assemblage thus far described, consists of two plate members, one of which, 44, is freely rotatable or oscillatable with respect to the bar 39, and the other of which, 42, is resiliently mounted with respect to the bar 39, for a purpose hereinafter described, but is substantially nonmovable during sharpening operations. The latter plate, 42, is provided with a finger or extension 50, positioned to engage the bottom edge of the housing for the guide bearings 21 and 46.

A set screw 5| provides means for adjusting the position of the unit on its bar 39, and for adjusting the unit relative to the presser foot bar 26, A rigid arm 52 i s secured to the lower end of the bar 39, and extends across the front of the machine slightly beyond the presser foot bar 26. At the end of the arm 52 is a roller bearing 53 which, by riding along the outer side of the presser foot'bar 26 provides a guide for the movement of the unit during sharpening operations.

The plate 44 is provided with studs 56 and 51 which form journals for the abrasive Wheels or discs 58 and 59, the abrasive discs being provided with suitable mountings such as the collars 66 and 6|. The grinding surfaces of the abrasive wheels are beveled to the desired angle of the cutting edge of the knife, and arranged so as to continue to impart the correct angle through the action of the grinder head, until the knife is used up, without any adjustment or stops.

Pinions 62 and 63 are also journaled on the studs 56 and 51, being rigidly secured to the respective abrasive discs 58 and 59, and positioned between the discs and the plate 44. It will be noted that the pinions 62 and 63 have threaded extensions upon which the collars or bushings 69 and 6| are mounted, and further that the heads of the studs 56 and 51 are screw threaded for ready detachment. This arrangement facilitates removal of the abrasive wheels and pinions for cleaning or replacement.

A pair of related pinions or a double pinion having axially spaced sets of teeth 64-64 is mounted for free rotation on the pin 46, with its respective portions on opposite sides of the plate 44. The outer pinion or portion thereof meshes with the teeth of the pinions 62 and 63 and the inner portion is positioned to mesh with teeth forming a rack 65 on the presser foot bar, whereupon as the sharpening unit is manipulated by hand to raise or lower it, the pinion 64-64 will rotate along the rack 65, and in turn cause the abrasive discs 56 and 59 to be rotated, since they are threaded upon the extensions of the respective pinions 62 and 63.

It will be observed that the arrangement of pinions, just described, provides a planetary gearing in which the pinions 62 and 63 are rotatable about their own axes, as well as about the axis of the pinion 64. Consequently, as the sharpener unit begins a new stroke in either direction, the rotatable plate 44 will automatically swing on the axis of the pinion 64 to present one or the other of the abrasive discs to the knife at a proper angle. By suitable adjustment and proportioning of the discs, both discs can be simultaneously presented to opposite sides of the knife,

- if desired.

This planetary arrangement together with the oscillatable plate 44, regardless of whether mechanically or hand operated through the handle 45, permits a ready switching of the abrasive discs from one position to another, to facilitate sharpening of the beveled edge at the bottom of the knife in a very accurate manner.

A spring pressed latch 61 is located at the side of the frame, and by cooperation with a keeper 68 serves to hold the sharpener unit up out of the way when the machine is to be used for cloth cutting. At the same time the unit is readily accessible and can be quickly released for grinding purposes.

From the foregoing description the operation of the sharpener will be readily apparent. With the knife IS in motion, reciprocating vertically, the grinder head is manually raised and lowered throughout the extent of the knife, grinding first one side andthen the other, the planetary gearing serving automatically to properly position the abrasive discs 56 and 59, with the proper degree of pressure. As the unit is moved up and down, the rack 65 serves to impart a continuous rotation to the abrasive discs whereby the discs constantly present a fresh abrading surface to the knife, thus avoiding undue and uneven wear, and also avoiding any tendency towards clogging of the discs.

The resilient mounting, indicated at 43-43a, is effective to maintain the pinion unit 6464 in engagement with the rack bar 65 to insure operation of the grinder unit for sharpening purposes. However, when the machine is to be used for cutting purposes, and it is necessary to latch the sharpener unit out of the way, by means of the latch 61 and keeper 68, it is also essential to disengage the planetary gearing from the rack 65 in order that the presser foot may perform its usual functions. This disengagement is effected by the abutment of the finger or extension 56 against the bottom of the housing for the guide bearings 21 and 40, and by virtue of the resilient or yielding mounting 4343a for the grinder head, the head will be tilted downwardly and away from the presser foot bar sufliciently to break the mesh between the pinion 64 and the rack 65. Thus, the mere act of latching the grinder unit automatically, disengages the gearing from the rack on the presser foot bar, leaving the presser foot free to move. The plate 42, the set screw 5| and the bar 39 will, of course, be suitably adjusted to permit of this movements, and to provide sufficient clearance between the gear 64 and the bar 39.

The plate 44 is provided with fingers or projections 66 which serve to position the grinding wheels automatically for locking in the right position when not in use, and to prevent the bolt head which holds the knife, from striking the grinding wheels on the upward sharpening stroke of the grinding head.

With a gearing such as described it is a comparatively simple matter to sharpen the bevel at the bottom or lower end of the knife, by rotating the plate 44 manually or mechanically to properly position the grinding discs.

Customarily the presser foot bar is directly in front of the knife edge and acts in a measure as a guard therefor. The slight offsetting of the presser foot bar in the present structure in no wise minimizes this safety function, but if desired, as an extra measure of caution a guard 69 may be provided, and by pivotal mounting thereof can be swung down in front of the knife or swung up as shown in Figure 1, to be out of the way when not desired.

While the preferred form of unit includes the planetary gearing, a very satisfactory unit may be had without such gearing. In Figures '7 and 8 there is illustrated a simple modification, in which the abrasive discs 16 and H are journaled on a plate 12 which is rotatably mounted on a stud 13 in a head 14 secured to the bar 39. The stud 13 extends into a handle 75, this handle serving for manual movement of the unit along the length of the knife and for rotary movement into and out of engagement with the knife. The grinding surfaces of the discs or wheels 10 and H are of course beveled to the proper angle.

In Figures 9 and 10 there is illustrated another modification in which the discs of abrasive are substantially rectangular rather than round. In this instance the discs 16 and 11 are pivotally mounted or hinged to studs 18 and 19, the remainder of the unit being the same as described in Figures '7 and 8. This form of the invention is subject to clogging but offers the advantages of simplicity and inexpensiveness, and the blocks need be beveled only on the surfaces adjacent the knife.

A further modification is illustrated in Figures 11, 12 and 13, wherein the abrasive discs 86 and 8! are positioned in a plane at right angles to the previously described forms, and in a plane laterally of the knife. The head 82 of the unit carries a handle 83 by means of which the unit may be manipulated, and also supports a planetary gearing consisting of a central pinion 84 and outer pinions 85 and 86 by means of which the abrasive discs may be rotated during manipulation of the unit.

In this form of the invention the abrasive discs may be power driven as by a rotating shaft 81. A suitable power drive might take the form of the telescoping shaft arrangement and driving mechanism illustrated in the patent to Wagner, No. 1,815,017, dated July 14, 1931, to which patent reference may be made for a more complete description of details.

The heads '14 and 82 of these modifications may be secured to the bar 39 in any conventional manner, either detachably in the manner shown in Fig. 4, or as illustrated, integrally.

An advantage of the adjustable stop 37 at the top of the bar 39 (or 39) is that adjustments of the bar and sharpening unit to the correct depth for catching the bottom of the knife may be made. Some knives are beveled at a greater angle than others, and this adjustment permits grinding of the bottom of the knife perfectly, regardless of its bevel.

Many other modifications will occur to those skilled in the art and the description herein is to be regarded as illustrative rather than as limiting. For example friction wheels might well be used in lieu of the planetary gearing, and. in place of the gearing 64-65. The sharpener unit may be made separate from the cutting machine, attached thereto, or built in as an integral part.

Again it is not essential that the driven elements operate from the presser foot bar, since an auxiliary rod might be applied for the purpose, or for that matter the drive might be geared to, or operable by friction against the standard of the knife. As illustrative of a form which the drive might take, reference may be made to Fig. 16 wherein is shown a rod 260. which may be the presser foot bar, or may be an auxiliary rod, and. a drive roll 64a, supplied in lieu of the gear 64 and operable by friction against the bar or rod 26a. Otherwise, the structure is the same as shown in Fig. 3.

The drive of the planetary gears from some portion of the machine such as the rack 65 might be omitted entirely and the planetary gearing operated by hand to switch the emeries from one position to another, or to rotate them.

It may be found desirable to control the oscillating and other movements of the grinder head from the top of the machine, 1. e., at a point adjacent the top of the bar 39, and in Figs. 14 and such a control is illustrated. This control may well consist of a rotatable handle 88 rigid with a lever 89, which lever 89 is connected by a link 90 to a socket arm 9| mounted on the handle 45.

By this means, the entire grinder unit may be controlled from above to eliminate any tendency towards a binding action which might be produced by virtue of the handle 45 and knob 41 being off center. Obviously, any conventional equivalent connection between the handle 88 and the handle 45 might readily be substituted.

Although several forms of a manually operable sharpener have been illustrated, it is pointed out that driven discs such as shown in the preferred form offer a number of advantages. The main reason for the geared action is to hold in check and avoid rapid rotation of the abrasive wheels. Without this check they would tend to rotate with simple movement and be non-abrasive. When the operator raises and lowers the unit by the handle the center gear engaged in the rack rotates the wheels insuring that new abrasive surfaces are always applied to the knife edge.

Among the advantages of all forms of the invention is the fact that a unit such as described will not burn the blade, will not harm the standard and will keep the knife at a perfectly even,

,- accurately beveled cutting edge.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a cloth cutting machine, the combination with a reciprocating knife, of a shaft extending parallel to the edge of said knife and mounted for movement lengthwise of the knife, a grinder head secured to an end of said shaft and movable therewith, an abrasive wheel carrier oscillatably mounted in said head, a pair of abrasive wheels mounted for rotary movement on said carrier and movable into and out of engagement with said knife upon oscillation of said carrier, a presser foot bar extending parallel to said grinder head shaft and knife, said bar having teeth forming a rack longitudinally thereof, a pinion in said head on one side of said carrier, positioned to mesh with said rack for rotation there along when said head is moved along the length of the knife, and planetary gearing comprising a driven pinion on the opposite side of said carrier, rigid with said first mentioned pinion and a planet gear rigidly aligned with each of said abrasive wheels, said planet gears each being in mesh with said driven pinion, for rotation thereby about their own axis during movement of the grinder head, and for rotation therearound during oscillation of the carrier.

2. In a cloth cutting machine, the combination with a reciprocating knife, of a shaft extending parallel to the edge of said knife and mounted for movement lengthwise of the knife, a grinder head secured to an end of said shaft and movable therewith, an abrasive wheel carrier oscillatably mounted in said head, a pair of abrasive wheels mounted for rotary movement on said carrier and movable into and out of engagement with said knife upon oscillation of said carrier, 2. presser foot bar extending parallel to said grinder head shaft and knife, said bar having teeth forming a rack longitudinally thereof, a pinion in said head on one side of said carrier, positioned to mesh with said rack for rotation there along when said head is moved along the length of the knife, and planetary gearing comprising a driven pinion on the opposite side of said carrier, rigid with said first mentioned pinion and a planet gear rigidly aligned with each of said abrasive wheels, said planet gears each being in mesh with said driven pinion, for

rotation thereby about their own axis during movement of the grinder head, and for rotation therearound during oscillation of the carrier, said carrier being mounted in said head such that said oscillation of the carrier, and rotation of the planet gears are automatically reversible upon a reversal of movement of said grinder head.

3. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement through a plane parallel to the plane of the cutting edge of the knife, a pair of abrasive wheels mounted for rotary movement on said head and for oscillatory movement into and out of engagement with the edge of said knife, a gear member fixedly mounted in said machine, independently of the grinding mechanism and planetary gearing mounted in said head in operative relation to said abrasive wheels, said planetary gearing operatively engaging said gear member to rotate said wheels and control movement of said grinder head, and means to move said grinder head relative to said fixed gear member.

4. In a cloth cutting machine, the combination with a reciprocating knife, of a shaft mounted for movement lengthwise of the knife, a grinder head secured to said shaft, and mounted for movement therewith, lengthwise of the knife through a plane parallel to the plane of the cutting edge of the knife, an abrasive wheel carrier oscillatably mounted in said head, an abrasive wheel mounted for rotary movement on said carrier and movable into and out of engagement with said knife upon oscillation of the carrier, a rack extending longitudinally of said knife and parallel thereto, a pinion in said grinder head adjacent said carrier and positioned to mesh with said rack for rotation therealong when said head is moved lengthwise of the knife,

and planetary gearing in said head connected to i said pinion for actuation thereby upon movement of said grinder head along the rack.

5. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement lengthwise of the knife through a plane parallel to the plane of the cutting edge of the knife, a grinding means carrier mounted oscillatable in said head, grinding means mounted for rotary movement on said carrier and for oscillatory movement therewith into and out of engagement with the knife, driving means on said grinder head for rotating said grinding means and for moving said grinding means through an oscillatory path into and out of engagement with the knife, and means including a relatively fixed element in the cutting machine forming a part thereof independent of the grinding mechanism, engageable with said driving means and effective to cause an actuation thereof.

6. In a cloth cutting machine, the combination with a reciprocating knife, of a shaft extending parallel to the edge of said knife and mounted for movement lengthwise of the knife, a grinder head secured to an end of said shaft and movable therewith, an abrasive wheel carrier oscillatably mounted in said head, a pair of abrasive wheels mounted for rotary movement on said carrier and movable into and out of engagement With said knife upon oscillation of said carrier, a relatively fixed member extending parallel to said grinder head shaft, driving means in said head for rotating said abrasive wheels and for moving said carrier into and out of-engagement with said knife, and means to operatively connect said driving means to said relatively fixed element whereby said driving means will be actuated by said fixed element upon movement of the grinder head therealong.

7. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, and means to rotate said sharpening means by movement of said grinder head along the knife, comprising a driven sun gear, and a planet gear effective to directly actuate said sharpening means, in mesh with said sun gear.

8. In a cloth cutting machine, the combination with a reciprocating knife, of a oscillatable grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, and said head including means to oscillate said sharpening means into and out of engagement with the edge of the knife.

9. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, and disposed at opposite faces of the knife, means to rotate said sharpening means by movement of said grinder head along the knife, said head including means to swing said sharpening means into and out of engagement with the edge of the knife on one face thereof, and to reverse the position of said sharpening means automatically at the beginning of a stroke in either direction along the knife, to engage the sharpening means with one face of the knife, and to disengage the sharpening means from the other face of the knife.

10. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried 3 by said head, means to rotate said sharpening means by movement of said grinder head along the knife, said head including means to swing said sharpening means into and out of engagement with the edge of the knife, and to reverse the direction of rotation of said sharpening means automatically at the beginning of the stroke in either direction along the knife.

11. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, said head including means to swing said sharpening means into and out of engagement with the edge of the knife, and to reverse the position of said sharpening means automatically and to reverse the direction of rotation thereof at the beginning of a stroke in either 5 direction along the knife.

knife, a rotary sharpening member for the knife carried by said head, means to rotate said sharpening member by movement of said grinder head along the knife comprising a driven sun gear, and

a planet gear secured to said sharpening member, 1n mesh with said sun gear, and means to drive said sun gear.

13. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, and means, including a driven sun gear, and a planet gear secured to said sharpening means, in mesh with said sun gear, to rotate said sharpening means by movement of said grinder head along the knife, comprising a relatively fixed member adjacent the edge of the knife and a rotatable pinion means operatively connected to said sun gear and positioned to rotate along said relatively fixed member as the grinder head is moved along the edge of the knife.

14. In a cloth cutting machine, the combina tion with a reciprocating knife and a presser foot bar, of a grinder head mounted for movement through a path parallel to the edge of said knife and to said presser foot bar, sharpening means for the knife rotatably mounted in said head, and means including said presser foot bar to rotate said sharpening means during movement of said grinder head along the knife.

15. In a cloth cutting machine, the combination with a reciprocating knife and a presser foot bar, of a rack formed in said presser foot bar, a grinder head mounted for movement along the edge of the knife, sharpening means for the knife rotatably mounted in said head, and means in- L cluding said rack to rotate said sharpening means during movement of said grinder head along the knife.

16. In a cloth cutting machine, the combination with a reciprocating knife, of a shaft parallel to the edge of said knife and mounted for movement lengthwise of the knife, a grinder head carried by said shaft, an abrasive disc carried by said head, means to move said disc into and out of contact with said knife during normal operation of the grinder, and means to rotate said disc at a definite rate of speed unrelated to the speed of reciprocation of the knife, during movement of said grinding head.

17. In a cloth cutting machine, the combina- ,1

tion with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife rotatably mounted in said head, and means to rotate said sharpening means by movement of said grinder head along the knife, comprising a planetary gear train in said head, a relatively fixed member positioned adjacent the path of movement of said head, and means to yieldingly engage an element of said gear train with said relatively fixed member whereby to drive said train by movement of said grinder head.

18. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife rotatably mounted on said head, means, including a driven sun gear, and a planet gear secured to said sharpening means, in mesh with said sun gear, to rotate said sharpening means by movement of said grinder head along the knife, and means to secure said grinder head in an inoperative position in the machine.

19. In a cloth cutting machine, the combination, with a reciprocating knife, and a presser foot bar, mounted for adjustment to desired elevations along the knife, of a grinder head mounted for movement through a path parallel to the edge of said knife and to said presser foot bar, and for oscillatory movement relative to said knife sharpening means for the knife rotatably mounted in said head, means including said presser foot bar to rotate said sharpening means during movement of said grinder head along the knife, and oscillatory movement upon a reversal of the movement of the grinder head along the knife andmeans to latch said presser foot bar at any desired elevation.

20. In a cloth cutting machine, the combination with a reciprocating knife, and a presser foot bar, mounted for adjustment to desired elevations along the knife, of a grinder head mounted for movement through a path parallel to the edge of said knife and to said presser foot bar, sharpening means for the knife rotatably mounted in said head, means including said presser foot bar to rotate said sharpening means during movement of said grinder head along the knife, and means to latch said presser foot bar at any desired elevation, comprising a rack on said presser foot bar, and a toothed member mounted on the frame of the machine for movement into and out of engagement with the teeth of the rack.

21. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, comprising a pair of spaced abrasive discs revolvably mounted on the head at opposite sides of the knife, and means, including a driven sun gear and a pair of planet gears secured respectively to said abrasive discs, and meshing with said sun gear, to oscillate said head and by such oscillation move the abrasive discs respectively into and out of engagement with the cutting edge of the knife.

22. In a cloth cutting machine, the combination with a reciprocating knife, of a shaft mounted for movement lengthwise of the knife, a grinder head secured to said shaft, and mounted for movement therewith, along the edge'of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, means to oscillate said head to position said grinding means at different points of engagement with said knife, and manually controlled means for effecting such oscillation to produce an alternate grinding action on the bottom cutting edge of the knife.

23. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife mounted in said head, means to actuate said sharpening means by movement of the grinder head along the knife, comprising gear means in said head, a relatively fixed member positioned adjacent the path of movement of said head, and means to yieldingly engage and disengage said gear means with respect to said relatively fixed member during normal grinding operation, whereby to render said sharpening means operative and inoperative.

24. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement along the edge of the knife, a pair of abrasive wheels mounted for rotary movement on said head and for movement into and out of engagement with the knife edge, a gear member fixedly mounted in said machine, planetary gearing mounted in said head in operative relation to said abrasive wheels, said planetary gearing operatively engaging said gear member, means to move said grinder head relative to said fixed gear member, and means to yieldly engage and disengage said planetary gearing with respect to said fixed gear member, whereby to render said sharpening means operative and inoperative.

25. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement along the edge of the knife, a pair of abrasive wheels mounted for rotary movement on said head and for movement into and out of engagement with the knife edge, a friction member fixedly mounted in said machine, planetary gearing mounted in said head in operative relation to said abrasive wheels, said planetary gearing operatively engaging said friction member, means to move said grinder head relative to said fixed friction member, and yieldable means to frictionally engage and disengage said planetary gearing with respect to said friction member, whereby to render said sharpening means operative and inoperative.

26. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, including gearing for said sharpening means, pinion means to actuate said gearing, and means to yieldably engage and disengage said pinion means and gearing with a relatively fixed member in the machine, whereby to render said sharpening means operative and inoperative.

27. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, including gearing for said sharpening means, pinion means to actuate said gearing, means to yieldably engage and disengage said pinion means and gearing with a relatively fixed memher in the machine, whereby to render said sharpening means operative and inoperative, and means to swing said sharpening means into and out of engagement with the edge of the knife.

28. In a cloth cutting machine, the combination with a knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, means to bring said sharpening means into and out of engagement with the edge of the knife, and means to vary the pressure of the sharpening means against the edge of the knife thereby to vary the sharpening effect.

29. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife, said head including means tooscillate said sharpening means into and out of engagement respectively with the opposite faces of the edge of the knife, to reverse the position of said sharpening means automatically at the beginning of a stroke in either direction along the knife, and means to vary the pressure of the sharpening means against the edge of the knife thereby to vary the sharpening effect.

30. In a cloth cutting machine, the combination with a reciprocating knife, of a grinder head mounted for movement along the edge of the knife, sharpening means for the knife carried by said head, means to rotate said sharpening means by movement of said grinder head along the knife comprising a planetary gear train, means to drive said train, and means to vary the pressure of the sharpening means against the edge of the knife thereby to vary the sharpening effect.

LOUIS CHARLES BLESCI-I.

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