US2308012A - Sharpening device - Google Patents

Description

`gan. 12%, 1941i A. P. KoMowl SHARPENING DEVICE Filed Nov. 20, 1940 gin W ATTORN EYS Jan. 12, 1943.l

' A. P. KOMOW SHARPENING DEVICE Filed Nov. 2o. 1940 `s sheets-sheet 2 INVENTOR.

ATTORNEYS l Jan.12,1943.. A. P. koMow 2,308,012

SHARPEN ING DEVICE Filed Nov. 20, 1940 s Smets-sheet 3 Fles.

v INVEFOR. v BY @lle/1f" ffm/w FIG-8,

ATTORNEY.r

Patented Jan. 12, 1943 f UNITED STATES PATENT lOFFICIE.

SHARPENING DEVICEr Application November 20, 1940, Serial No. 366,401

Claims.

My invention relates to a new and improved sharpening device for a cloth-cutting machine of the reciprocating straight-knife type.

One of the objects of the invention is to provide a presser-foot which can be held at any desired adjusted height and which is turned automatically by the grinder-mechanism to the respective inoperative and operative positions of said presser-foot without changing the vertical adjustment of said presser-foot.

Another object of the invention is to provide grinder-mechanism which supports the grinding stones and which is depressed by hand and which is raised automaticallywhile theknife is rapidly reciprocated, `and which is automatically disconnected from the motor Which actuates said grinder-mechanism, when the grinder-mechanism has been raised to its top and inoperative position.

Another object of the invention isto provide improved means whereby the grinder stones are held above the top of the knife, in inoperative position, by manually releasable mechanism.

Other objects of my invention will be set forth in the following description and drawings which illustrate a preferred embodiment thereof, it being understood that the above statement of the objects of my invention is intended generally to explain the same Without limiting it in any manner.

Fig. 1 is a side elevationof the improved device, the illustrations lof certain of the parts having been omitted, in order to show certain interior constructionv more clearly. In this view, the rack-bar 2| is shown in a position which is below its top position.

Fig. 2 is a front elevation of the device illustrated in Fig. 1.

Fig. 3 is a sectional View on the line 3 3 of Fig. 1.

Fig. 4 is a sectional view on the line-4 4 of Fig. 1, with the rack-bar in its bottom position.

Fig. 5 shows the parts illustrated in Fig. 4, when the grinding stones are in their top inoperative position, in which said grinding stones are spaced from each other. In this view, the rack-bar 2| is in its top position.

Fig. 6 is a sectional View on the line B-x of Fig. 1.

Figs. 'I and 8 are respectively sectional views on the lines 1-1 and 8--8 of Fig. 4.

Fig. 9 is a sectional view on the line 9.-9 of Fig. 6.

The cloth cutting machine itself. may be of any suitable or standard construction. The cloth cutting machine comprises a base I, a handle 2 and 55 a motor casing 3. The knife 4 is of the usual type, being provided with a front cutting edge and alsowith a bottom cutting edge. Save for certain details which are necessary for the understanding of the invention herein, the mechanism whereby the motor in the casing 3 reciprocates the knife 4 is not illustrated, as such mechanism is Well-known per se.

Fig. 2 shows the shaftr 5 of the electric motor in the casing -3. The disc 6 is keyed or otherwise suitably rigidly connected to the shaft 5. The p in I is connected off-center to the disc E, and the head 8 of a connecting rod 9 is turnably mounted upon the pin 'I. The lower end of the connecting rod 9` is pivotally connected to the top of the knife 4. 'This connection is not shown, as it is wellknown. The annular periphery of the disc 6 is cut, in order to provide a Worm I0. This `worm I0 can mesh with a worm wheel II, Whose hub I4 is releasably xed to the turnable and vertical shaft I2. This shaft I2 is turnably located in the special bracket or housing I-I. The hub I5 of a bevel gear I6 is also suitably xed to the shaft I2, so that lthe worm wheel II and the bevel gear I6 turn in unison. The bevel gear lli-meshes With a companion bevel gear I'I, whose hub I8 is rigidly connected to a horizontal shaft I9. As shown in Fig. 2, the shaft I9 is provided with a pinion 20, which meshes with a rack 2|, which can be moved vertically up and down. The shaft I9 is provided With a suitable bearing 22. which is fixed to the frame of the machine. The bracket H is mounted turnably upon the bearing 22, so that saidr bracketH has a limited turning movement relative to the frame of the machine. The rack 2I is guided .in a suitable bore of the frame of the machine, independently of the bracket H, so that the movement of the rack 2| is always vertical.

The presser-foot 23 is pivotally connected by the lpivot pin 24 to the enlarged head 25 of the presser-foot rod 26. The rod 26 is provided with a vertical series of horizontal teeth 2l. The periphery of the presser-foot 23 is provided with a pair of* recesses 28v and 29. The head 25 of the rod 26 has a vertical recess in which a compression spring 30 is located. This spring 30 down- Wardly urges the ba1l'3I which can interfit partially with either of the recesses 28 and 29. The presser-foot'23 `may thus beheld releasably in the full-line position illustrated in Fig. 1, or in the broken-line position illustrated in said figure. Rod 26 can be vertically adjusted by hand, and for this purpose said rod 26 is provided with a nnger-hold33. "The rod 2vis suitably guided'in a vertical bore of the frame of the machine, so that the bracket H turns independently of the rod 26. The rod 25 can be adjusted so as to hold the presser-foot 23 at any desired height.

Conventional mechanism is used for this purpose. This mechanism comprises the conventional handle 34 which is turnably mounted in the bearing 35 of the frame of the machine. When this handle 34 is turned, it turns the eccentric 35, which is rigidly xed to said arm 34. The eccentric 36 operates a plunger 31, which actuates a latch which meshes with the teeth 21. This conventional mechanism is located in a part of the fixed frame, and it is covered by the removable cover plate 38.

The grinder stones 33 and 4i) are of the usual cylindrical shape and they are mounted upon shafts which are respectively perpendicular to each other. The shafts of the grinder stones39 and 44 are connected to bracket-members, which are mounted on a bracket 43 which is rigidly connected to the rack 2i. Fig. '7 shows the shaft 45a of the grinder stone 45. This shaft 45a has a threaded end 4I, which is fixed to a suitable tapped bore of the bracket-member 42. As shown in Fig. 6, the arm or bracket 43 is suitably fixed connected to the bottom of the rack 2|. As shown in Fig. '7, this arm or bracket 43 has a square cross-section. In addition to the bracket-member 42, said bracket 43 has another bracket-member 44. The bracket-members 42 and 44 are slidably connected to the bracket 43.

For this purpose the bracket 43 is provided with transverse bores 45 and 45. The shank 41 of a screw ts snugly in a bore of the bracket-member 42, and said shank 41 passes through the bore 45. The bore 45 is elongated, so that it guides the longitudinal sliding movement of the member 41 and of its associated bracket-member 42. The shank 41 passes through an elongated bore 43 of the bracket-member 44. The shank 49a of another screw 49 fits snugly in a -bore of the bracket-member 44, and said member 43a passes through the elongated bore 46 and it is located in the elongated bore 50 of the bracket-member 42. A covering washer 5I is located between the head of the member 49 and the bracket-member 42.

A compression spring 52 is located in the 1ongitudinal 'bore 52a of the bracketmember 43, and the respective ends of said compression spring 52 abut the Shanks 41 and 49. The spring 52 therefore urges the shanks 41 and 49a. away from each other, thus urging the bracket-members 42 and 44 to move in opposite directions relative to the bracket-member 43. These members 42 and 44 cannot turn relative to bracket 43, and they move relative to bracketmember 43 only in a direction parallel to the axis of bore 52a. Fig. 8 shows the shaft 39a of the stone 39, which is fixed `by means of its threaded end 365 to the bracket-member 44. The stones 39 and 45 turn freely relative to their respective shafts 33a and 40a, the usual assembly means being provided for this purpose. These stones may have any shape.

The compression spring 52 therefore urges the grinder stones 39 and 45 towards each other :and into operative contact with the vertical cutting edge of the knife 4, during the grinding operation. This knife 4 is connected to the usual knife-support 4a, which is slidably guided in a vertical guide recess of the frame of the machine.

As shownrin Figs. 4 and 9, abent resilient latch member 53 is rigidly connected to the bracket-member 44. A companion resilient stud or pin 54, of cylindrical shape, is connected to the bracket-member 42. This pin 54 operates as a supplemental latch member.

When the rack 2| is moved upwardly, the head 56 of the stationary cam 55 enters the space between the stud 54 and the corresponding adjacent part of the cam member 53. This is shown in Fig. 5, which also shows how the pin 54 and the adjacent convex portion of the cam member 53 releasably engage the shoulders 51. This cam 55 is fixed to the frame of the machine. The shoulders 51 of the cam 55 releasably hold members 53 and54.

In this position, the grinder stones 39 and 40 are separated from each other, as shown in Fig. 5, and adjacent the top of the knife, even when the knife has been moved upwardly to its top position. Since the cam 55 is rigidly fixed to the main housing of the machine, the bracket H can turn relative to said member 55.

A latch 58 is connected by a pivot pin 59 to the frame of the machine. A compression spring 50 urges the latch 58 to the position indicated in Fig. l, in which the extension 6| of said latch 58 engages a recess Gla of the housing H, sothat the housing H can be thus held, when required, in the operative position shown in Fig. l, in which the Worm I0 engages with the worm gear H. This operative position is also shown in Fig. 4.

The rack 2i is provided'with a screw Whose head 52 projects laterally from said rack. When the rack 2| is moved upwardly through a predetermined distance, the head 62 strikes the tail of the latch v58, thus releasing the housing H, which is then free to swing to the inoperative position which is shown in Fig. 5, in which the Worm wheel Il is out of mesh with the worm I0. The worm wheel II projects through a slot in the frame of the machine and a wall of said slot limits the movement of worm wheel I l, when housing H is turned. As soon as the latch 58 releases the housing H, the reaction of the teeth of worm wheel I I against the teeth of worm I0 is sufficient to turn the housing H to its normal inoperative position which is shown in Fig. 5. Means are provided for releasably locking the housing H in its inoperative position. These means comprise a latch 63, which is pivotally connected at 64 to the frame of the machine. The compression spring 65 urges the locking extension 66 of the latch 63 to enter the corresponding recess 66a of the housing H, as shown in Fig. 5.

The top of the rack 2l is provided with a knob 61 which has a ange 68 at the bottom thereof. When the rack 2l is manually depressed, the ange 68 strikes the latch 63, as shown in Fig. 4, thus releasing the housing H from the latch 63. The knob 61 also strikes the inclined branch of the spring 69, which is Xed to the housing H. The downward movement of the knob 61 therefore automatically releases the housing H from the latch 63, and it also automatically turns the housing H to its operative position in which worm I0 meshes with worm gear Il. 'I'he housing is then releasably held in this operative position by the latch 58. The downward movement of rack 2| rst moves head 62 away from latch 53.

Either of the bracket members 42 or 44 can be moved longitudinally through a limited distance, independently of the bracket 43. However, if one of the bracket members 42 or 44 is thus moved 4relative to the bracket 43, the spring 52 causes the simultaneous movement of the other bracket member. The grinder stones 39 and 46 can thus be moved relative to each other, in order to separate them, and both grinder stones can also be moved together in unison, relative to the bracket 43.

The operation of the device is as follows:

While the machine is used for cutting cloth, the rack 2| is held in its top position, in which the head 56 of the stationary cam member 55 holds the stones 39 and 40 separated from each other. The housing H is then releasably held in the inoperative position which is shown in Fig. by the latch 63. The stones are thus located upwardly relative to the knife, and the stones are laterally spaced from each other.

When it is desired to sharpen the knife, the rack 2| is forced down `by hand to its bottom position, while the electric motor in casing 3 rapidly reciprocates the knife. The bottom position of the rack and of the grinder stones is illustrated in broken lines in Fig. 1. The knife is thus ground or sharpened during the downward movement of the rack, as soon as the grinders are free to move laterally to operative position.

During this downward movement of the grinder stones, the presser-foot 23 is turned automatically from the operative full-line position illustrated in Fig. 1, to the inoperative broken-line position which is illustrated in said figure. The presserfoot 23 is held in said broken-line position, by means of the ball latch 3| and the recess 29. The knife 4 is rapidly reciprocated in the usual manner.

Since the worm I6 is now in mesh with the worm wheel Il, the rack 2| will be raised slowly while the grinders 39 and 4D are pressed against the opposite edges of the knife 4, in the manner shown in Fig 3. The friction between the edge of the knife and the grinder stones 33 and 40 will turn said grinder stones upon their respective shafts. While the bracket 43 is moved upwardly from its bottom broken-line position which is shown in Fig. 1, said bracket 43 will strike the nose 23a of the presser-foot 23, thus restoring the presser-foot 23 to the operative and full-line position which is shown in Fig. 1. At about the limit of the upward movement of the rack 2|, the head 56 of the cam 55 automatically separates the grinder stones 39 and 4|] which are then held in said separated relation, adjacent the top of the knife 4. The rotation of the bevel gear I5 then automatically turns the housing H to the inoperative position shown in Fig. 5, in which position the housing is held, until it is again necessary to sharpen the knife.

At the beginning of said downward movement of the rack 2| from it-s top position which is shown in Fig. 5, the extension 66 of latch 63 is in the recess 66a, so that housing H is held releasably in the inoperative position shown in Fig. 6. The head 62 is then in contact with latch 58, so that said latch is held with its extension 6| out of the recess Bla. When the head 62 is moved downwardly, the biasing spring 60 urges the extension 6| to enter the recess 6|a, but extension 6| -then cannot enter recess Gla, but said extension 6| is then spaced laterally from said recess 6|a.

Immediately at the commencement of the downward movement of the rack, the resilient pin 54 and the hook part of the resilient member 53 are released from the shoulders 51, so that the stones are moved to contact with the faces of the knife 4, during the downward movement of rack 2| and while the knife 4 is rapidly reciprocated by the motor.

At about the end of the downward movement of the rack, the knob 61 strikes the spring 69, thus laterally flexing said spring 69, which urges the housing H to its operative position which is shown in Fig. 5. The iiange 68 then strikes the latch 63, thus releasing extension 66 from recess 66a, so that the flexed spring 59 turns the housing H to its operative position. The exten-sion 6| of latch 58 is moved into recess 6|, thus locking housing H in its operative position. The shaft I9 is then rotated, so that pinion 26 moves the rack 2| upwardly, while the reciprocation of the knife 4 by the motor is continued. At about the end of the upward movement of rack 2|, the head 62 strikes latch 58, thus releasing extension 6| from recess 6|a. At about the same time, the cam 55 separates the stones from the edge of the knife. The torque which is produced by the pressure of the teeth of worm wheel against the teeth of worm I6, then automatically turns housing H to `its inoperative position, in which extension 66 can enter recess 66a.

Ordinarily a single downward and upward movement of the grinder stones relative to the frame of the machine is suflcient to sharpen the knife.

Since the grinder stones are hield laterally spaced from each other by the member 56, said grinder stones may then be located at the level of or below the level of the top of the knife, when the knife is in its top position or bottom position or intermediate said top and bottom positions.

The latches which respectively hold the bracket H in its operative and inoperative positions are of the snap type so that they automatically snap into holding positions, and the bracket H can be released from either of its positions, if

desired, by applying sufficient turning force to` said bracket.

I have shown a preferred embodiment of my invention, but it is clear that numerous changes and omissions can be made without departing from its spirit. For convenience I have described the device in the position in which the knife reciprocates in a vertical path, but of course the machine could be held in any suitable position.

I claim:

1. A cloth cutting machine which has a frame, a'knife which is mounted to reciprocate relative to said frame in a vertical path, a rack guided to reciprocate relative to said frame in a vertical path, said rack being spaced laterally from said knife, grinder members connected tol said rack' which contact with the opposite faces of the vertical cutting edge of said knife when said grinder means are located between the top of the knife and the bottom of the knife, said grinder members laterally movable to and fro relative to said faces of the cutting edge of the knife, spring means connected to said rack and urging said grinder members towards each other to contact with said opposite faces, said rack having vertically superposed teeth, a pinion in mesh with said teeth, a first horizontal shaft to which said pinion is connected, said first horizontal shaft having a bearing which is connected to said frame, a first bevel gear connected to said first horizontal shaft, a bracket turnably mounted on said rst horizontal shaft and rockable relative to the frame to respective operative and inoperative positions, a second shaft mounted in said bracket, said second shaft having a second bevel gear in mesh with said first bevel gear, a motor- `movably to said frame which holds said bracketreleasably in operative position, a secon-d latch connected to said frame which holds said bracket releasably in inoperative position, a memberl projecting laterally from said rack which actuates said first latch to release said bracket when the rack is in its upper position, another member connected to said rack which actuates said second latch to release said bracket when said rack is moved downwardly from its upper position, said last-mentioned member and a cooperating member on said housing which turns said housing to its operative position when the rack is moved downwardly.

2. A cloth cutting machine comprising a frame and a knife which is mounted to reciprocate to and fro relative to said frame in a predetermined path, a supporting rod guided in said frame to move to and fro in a path which is parallel to the path f movement of the knife, a bracket connected to said supporting rod and extending laterally from said supporting rod towards said knife, a first bracket member, a second bracket member, means slidably connecting said bracket members to said bracket and permitting each bracket member to move laterally to and fro relative to said supporting rod, a first shaft connected to the first bracket member and movable in unison therewith, a second shaft connected to the second bracket member and movable in unison therewith, each said shaft being laterally movable relative to the other respective bracket member, said bracket having a longitudinal bore through which said shafts pass transversely, a spring located in said bore and also located between said shafts, said spring urging said shafts away vfrom each other, grinder stones respectively turnably mounted on said shafts and movable into contact under the action of said spring with the respective opposite faces of the longitudinal cutting edge of said knife.

3. A cloth cutting machine having a frame and a knife which is mounted to reciprocate vertically relative to said frame, a vertically movable supporting rod which is spaced laterally from said knife, said supporting rod being downwardly manually movable, a lateral bracket connected to said supporting rod, supplemental lateral bracket members slidably supported on said lateral bracket, each bracket member having a grinder connected thereto, spring means which urge said shafts towards each other to bring said grinders respectively into contact with the respective opposite faces of the vertical cutting edge of said knife, a cam fixed to said frame, cam-members respectively fixed to said bracket members, said cam members being spaced laterally from each other when said grinder members contact with said faces, said cam being located and shaped to enter the lateral space between said cam members and to move said cam members away from each other when said supporting rod is raised to a predetermined position, a motor driven shaft adapted to be coupled to and to be uncoupled from said supporting rod, said shaft raising said supporting rod when said shaft is coupled to said supporting rod, means automatically uncoupling said shaft from said rod when said rod is at a predetermined height.

4. A cloth cutting machine having a frame and a knife mounted to reciprocate vertically relative to said frame, a supporting rod spaced laterally from said knife and mounted to reciprocate vertically, an actuating shaft mounted in said frame, a second shaft having means which actuate said supporting rod, a bracket turnably connected to said frame, said bracket being turnable to an operative position and to an inoperative position relative to said frame, said bracket having coupling means which couple said actuating shaft and said second shaft only when said bracket is in operative position, said supporting rod having grinders which are movable to contact respectively with the opposite faces of the longitudinal cutting edge of the knife, a movable latch which holds said bracket releasably in said operative position, said supporting rod having a member which holds saidV movable latch in release position when said supporting rod is in a predetermined position in which said grinders are held spaced from said faces, means which hold said bracket normally in inoperative position, said supporting rod having means effective upon its downward movement to turn the bracket to operative position. 5. A cloth-cutting machine of the type which has a frame and a knife which is adapted to reciprocate in a predetermined longitudinal path relative to said frame, a supporting rod which is movable wholly independently of said knife and which is guided in said frame to move toand-fro in a longitudinal path which is parallel to said longitudinal path of movement of said knife, said rod having a pair of shafts connected thereto, grinder stones respectively turnably mounted on said shafts, said shafts and said grinder stones being connected to be moved in unison with said rod when said rod is moved longitudinally to-and-fro in said longitudinal path of movement of said rod, said shafts being movable relative to said rod towards each other and away from each other in a lateral path which is lateral to said longitudinal path of movement of said knife, said shafts being also movable in unison relative to said rod in the same direction along said lateral path,-spring means associated with said shafts and biasing said shafts and said grinder stones towards each other until said grinder stones contact with the respective opposite faces of the cutting edge of the knife, said spring means being laterally movable in unison with said shafts when said shafts are moved in unison and in the same direction along said lateral direction.

ALBERT P. KOMOW.

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