US2761252A - Blade mounting fixture - Google Patents

Description

p 4, 1956 s. FICHERA 2,761,252

BLADE MOUNTING FIXTURE Filed Nov. 9, 1954 5 Sheets-Sheet 1 IN V EN TOR.

j SALVATORE FICHEHA ATTURNEVS.

Sept. 4, 1956 s. FICHERA 2,761,252

BUADE MOUNTING FIXTURE Filed Nov. 9, 1954 6 Sheets-Sheet 2 v INVENTOR.

V By SALVATORE FICHERA A T TORA/E Y8 Sept. 4, 1956 s. FICHERA BLADE MOUNTING FIXTURE 5 Sheets-Sheet 5 Filed NOV. 9, 1954 INVEN TOR. SALVATORE FICHERA ATTORNEYS.

United States Patent BLADE MOUNTING FIXTURE Salvatore Fichera, Philadelphia, Pa.

Application November 9, 1954, Serial No. 467,738

6 Claims. (11. 51-92 I This invention relates to a fixture for mounting a Wide variety of blades in many adjusted positions for sharpening or resharpening by a conventional grinding wheel.

An important object of the invention is to provide a blade holding fixture in which the blade holder is mounted upon a carriage that can be manually reciprocated in a plane substantially parallel to the axis of rotation of the grinding wheel and in which the stroke of the carriage may be adjusted for the length of the cutting edge to be sharpened.

Another object of the invention is to provide a blade mounting fixture including a blade holder that can be adjustably mounted on a carriage to assume various angular positions depending upon the desired bevel of the cutting edge.

Another object of the invention is to provide a blade mounting fixture wherein the blade holder can be adjustably retained at a desired position towards and away from the grinding wheel by a spring-loaded retractible means permitting rapid replacements of blades in the blade holder.

And yet another object of the invention is to provide a blade or knife mounting fixture which is relatively inexpensive and which can be easily operated with a minimum of manipulative skill.

These and other objects of the invention will become of Figure 2;

Figure 6 is a side elevation looking from the left of Figure 5;

Figure 7 is a fragmentary side elevational view of a modified form of the invention;

The fixture comprises a support 10 preferably in the form of a U-bar having a lower leg 12 adapted to re ceive bolt or screw means 14 to attach the same to a table in front of a conventional grinding or sharpening wheel 16, the support extending in a plane generally perpendicular to that of, the grinding wheel as shown in Figure 3. The upper leg 18 has an upper flat surface upon which is slidably mounted a reciprocable carriage 2,761,252 Patented Sept. 4,1956

20, the latter being preferably a substantially rectangularplate which is somewhat larger than the upper leg 18 of the support.

The slide connection between the carriage and the support is effected as follows. A pair of spaced elongated slots 22 and 24 are provided through the carriage and extend longitudinally thereof. Headed lugs 26 and 28 extend loosely through the slots and are threadedly secured at their lower ends to the upper leg 18 of the support as at 30 and 32, washers 34 being interposed between the support and the carriage.

A blade holder 36 is mounted on the carriage for movement therewith, the blade holder mounting a blade 38 having a cutting edge 40 to be sharpened across and against the grinding wheel. A means is provided to adjust the stroke of the carriage so that the latter can be manually operated in such a manner that the cutting edge only of the blade will be moved to and fro across the grinding wheel. This means comprises a first set screw 42 which is movably threaded through one side 44 of the carriage and extends into the slot 24, the inner end of the set screw bearing against the lug 28. Movably threaded through theopposite side 46 of the carriage is a second set screw 48 which extends int-o the other slot 22. A spring 50 is wound about the inner end of the second set screw 48 and terminally bears against the other lug 26 and the outer wall of the other slot 22, the spring normally urging the carriage to the left of the figures.

Thus by turning the set screws as shown in the dotted lines of Figure 4, the position of the cutting edge 40 relative to the grinding wheel and the adjustment of the carriage stroke to conform with the length of the cutting edge can be readilyaccomplished. After the proper adjustment is made, finger pressure is applied to the side 46 of the carriage moving the same to the right against action of the spring 50. This moves the cutting edge 40 across and against the grinding wheel in one direction. Releaseof the carriage will cause the spring 50 to move the same to' the left back to its original position whereby the cutting edge is moved across and against the grinding wheel in an opposite direction. The operation is repeated until a proper cutting edge is ground.

Theblade holder 36 is mounted on the carriage in such: a manner that it can be retractably adjusted towards and awayfrom the grinding wheel. This is accomplished by mounting the blade holder on a block 5'2. Apropriately secured to one longitudinal side 54 of the carriage is a guide member, preferably bars 56 and 58, which slidably abut the sides of the block 52. A bore 60 ex tends through the carriage and opens through the longi tudinal side 54 and its opposite side 62. A rod 64 extends .its other longitudinal side 62 is threaded as at 70; A

knurled nut 72 is received on the threads 70 exteriorly of the side 62 of the carriage. A'spring 74 is wound about the rod 64 and terminally bears against the block 52 and the side 54 of the carriage,ythe spring urging block outwardly away from the carriage and towards the grinding wheel and at the same time causing the nut 72 to bear against the side 62 ofthe carriage, as shown clearly in Figure 3. i i

Thus'to adjust the blade and blade holder to a desired position against the grinding wheel the head 68 is rotated while the nut 72 is held against rotation as shown: in dotted lines in Figure 3. After a blade has been sharpened and one desires to sharpen additional blades of the same kind, an outward pull is exerted on thehead 68 against action of the spring 74. When held in this? position, the blade is changed in the holder 36 and the H head 68 and rod 64 are released. This automatically positions the new blade against the grinding wheel in the prev1ously adjusted position; thus simplifying repetitive sharpening. i i

To free the operators hand from holding the nut 72 againstrotation during adjustment and when the rod 64 has been retracted against the spring 74, the device can be modified as shown in Figures 7-9. A pin '76 is secured in the end 62 of the carriage and extends perpendicularly therefrom. A slot 78 is cut through the margin of the knurled nut 72 and is adapted to removably receive the pm as shown in Figures 7 and 8. In this position, the operator can adjust the blade towards andaway from the grinding wheel by merely turning the head 68. To retract the blade holder for reinsertion of a like blade, the head 68 is pulled outwardly and turned slightly so that it bears against the free end of the pin as shown .in Figure 9. After the blade is changed, the head 68 is turned back to assume its original position and then released.

The final adjustment required is the angular position of the knife or cutting edge relative to the grinding wheel to obtain a desired degree of bevel. This is accomplished by providing a blade or knife holder 36 which is in the form of a clamp having a lower jaw 80 to one end of.

which is pivoted as at 82 an upper jaw 84. The shank of any blade 38 is retained between the jaws by means of a spring-loaded screw 86 which extends through the jaws 30 and 84 and into a depending bar 88. The bar 88 is adjustably held on the block 52 by means of a set screw 90 which is movably threaded through the bar 88 and the block 52. Thus the angular position of the blade holder 36 relative to the block and grinding wheel may be adjusted by the set screw 90 as shown in dotted lines in Figure 3.

Although any type of knife or blade can be retained in the blade holder by simply clamping the shank thereof between the jaws 80 and 84, some blades do not have a cutting edge at the end of a shank but rather at a portion along the length of the shank. Such a blade is illustrated in the drawings and is generally used on combined cloth stitching and cutting machines, such as 245 Singer Machines wherein the blade functions to cut the cloth at a predetermined short distance from the stitching. When such a blade is to be sharpened, it is mounted by set screws 92 on an adapter 94 which has a perpendicular shank 96 that is received in the blade holder 36.

Thus it will be seen that a knife or blade mounting fixture is provided in which the blade can be readily adjusted against a grinding wheel for any desired angle of bevel and degree of cut, which can be adjustably reciprocated transversely of the grinding wheel and which can be easily manipulated for changing knives or blades.

While preferred embodiments of the invention have been shown and described herein, it will be understood that skilled artisans may make minor variations without departing from the spirit of the invention and the scope of the appended claims.

I claim:

1. In combination with a grinding wheel, a blade mounting fixture comprising a support, a carriage slidably mounted on said support in front of said grinding wheel for reciprocating movement in a plane substantially parallel to the axis of rotation of the grinding wheel, means to adjust the stroke of the carriage, a blade holder slidably mounted on said carriage and means to adjustably move said blade holder towards and away from the grinding wheel, said means to adjust the stroke of the carriage including spaced elongated slots in the carriage, lugs carried by the support and extending loosely through said slots, a first set screw extending into one of said slots and bearing against one of said lugs, a second set screw extending into the other slot and a spring wound about said second set screw and bearing against the other lug.

2. In combination with a grinding wheel, a blade mounting fixture comprising a support, a carriage slidably mounted on said support for reciprocating movement in a plane substantially parallel to the axis of rotation of the grinding wheel, means to adjust the stroke of the carriage, a blade holder slidably mounted on said carriage and means to adjustably move said blade holder towards and away from the grinding wheel, said blade holder including a block, a pair of guide bars mounted on one side of the carriage on both sides of said block, said means to adjustably move said blade holder including an elongated rod extending slidably through said one side and the opposite side of the carriage, one end of the rod being rotatably connected to said block and the other end of the rod including threads, a nut received on said threads exteriorly of the opposite side of the carriage, and a spring wound about said rod and terminally bearing against said block and said one side of the carriage, said spring urging said block outwardly of said one side of the carriage.

3. The combination of claim 2 and a means to removably retain said nut against rotation relative to the carriage.

4. In a blade mounting fixture having a support and a carriage mounted thereon, said carriage having two opposing sides, a guide member extending from one side of the carriage, a block positioned in said guide member, a blade holder mounted on said block, and retractable means for adjusting the position of said block and said blade holder towards and away from said carriage, said means including a bore extending through said carriage and the two opposing sides thereof, a rod slidable in said bore and rotatably secured at one of its ends to said block, the other end of said rod being threaded, a nut received on said threads exteriorly of said carriage, a spring on said rod terminally bearing against said block and said one side of said carriage, said spring urging said block outwardly of said carriage and said nut against the opposite side of said carriage and a means to hold said nut spaced from said carriage when said block and blade holder have been retracted against action of said spring, said nut holding means including a pin extending from the opposite side of said carriage and a slot through the margin of said nut serving as clearance for said pin.

5. In a blade mounting fixture having a support and a carriage mounted thereon, said carriage having two opposing sides, a guide member extending from one side of the carriage, a block positioned in said guide member, a blade holder mounted on said block, and retractable means for adjusting the position of said block and said.

blade'holder towards and away from said carriage, said means including a bore extending through said carriage and the two opposing sides thereof, a rod slidable in said bore and rotatably secured at one of .its ends to said block, the other end of said rod being threaded, a nut received on said threads exteriorly of said carriage, and a spring on said rod terminally bearing against said block and said one side of said carriage, said spring urging said block outwardly of said carriage and said nut against the opposite side of said carriage said blade holder being adjustably pivoted on said block.

6. In combination with a grinding wheel, a support, a carriage having two opposing sides one of which extends substantially parallel to the axis of rotation of the grinding wheel, means mounting said carriage on said support for sliding movement along a plane substantially parallel to the axis of rotation of the grinding wheel, a guide member extending from said one side of the carriage, a block positioned in said guide member, a blade holder, means adjustably pivoting said blade holder on said block, and retractable means for adjusting the position of said block and said blade holder towards and away from said carriage, said retractable means including a bore extending through said carriage and said two opposing sides, a rod slidable in said bore and rotatably secured at one of its ends to said block, the other end exteriorly of said carriage, and a spring on said rod terminally bearing against said block and said one side of said carriage, said spring urging said block outwardly of said carriage and said nut against the opposite side of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS 213,496 Curtiss Mar. 25, 1879 6 Carr Nov. 2, 1886 Smith June 26, 1894 Kayetan June 18, 1912 Tatosian Oct. 25, 1921 Bergstrom May 25, 1926 Killian Aug. 17, 1926 Weed Sept. 27, 1938 Pastore Oct. 12, 1948

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