US2715305A - Slicer knife sharpener - Google Patents

Description

Aug. 16, 1955 J. D. BROWN 2,715,305

SLICER KNIFE SHARPENER Filed Feb. 28, 1952 2 Sheets-Sheet l 3 nventor JAMES 0 BROWN attorney;

g- 15, 1955 J. D. BROWN 2,715,305

SLICER KNIFE SHARPENER Filed Feb. 28, 1952 2 Sheets-Sheet 2 Zmventor JA MES [7. BROWN (Ittornegi United States Patent sLIcER KNIFE SHARPENER James D. Brown, Toledo, Ohio, assignor to Toledo Scale Company, Toledo, Ohio, a corporation of New Jersey Application February 28, 1952, Serial No. 273,820

6 Claims. (Cl. 51-248) This invention relates to slicing machines, and in particular to a device for sharpening the rotary knives thereof.

Prior art sharpening devices for the knives of slicing machines have been, in general, of the spring or cam engageable type having a grinding wheel and a honing wheel arranged to simultaneously contact opposite sides of the cutting edge of the knife. While, for the most part, prior art sharpening devices of this type have performed satisfactorily, certain disadvantages have been inherent in having the sharpening wheels mechanically engageable with the knife, and in having them contact the knife simultaneously.

The instant invention provides a sharpening device for the rotary knife of a slicing machine which has finger-engageable grinding and honing wheels, thereby allowing sharpening to take place by touch, and also provides independently operated grinding and honing wheels which allow for either or both to be in contact with its respective side of the knife at one time.

it is a primary object of this invention to provide for the rotary knife of a slicing machine a sharpening unit with individual grinding and honing wheels which are finger-engageable with the knift either separately or together.

A further object is to provide a storage space for a detachable slicer knife sharpener which eliminates the necessity of having a bulge protruding from the portion of the machine adjacent the knife.

Another object is the provision of finger-engageable grinding and honing wheels for sharpening the cutting edge of a circular knife which permits the sharpening to take place by human touch.

Still another object is the provision of an improved type of sharpening mechanism for the rotary knife of a slicing mach ne which permits greater ease of operation.

Other objects and advantages will be apparent from the following description, in which reference is had to the accompanying drawings.

According to the invention, a knife sharpening unit comprising independently operated grinding and honing wheels is adapted to be removably attached to the gauge plate of a slicer with the wheels arranged to engage opposite sides of the marginal area of a knife to sharpen the knife. The wheels are engaged with the knife by means of a finger-depressible lever operably connected to each wheel, said levers both being depressible in the same directiomby two fingers of one hand. Either wheel may be operated separately or both simultaneously, thereby causing either or both wheels to engage the knife as desired.

in the drawings:

Figure I is a view in perspective of a slicing machine showing the position occupied by the sharpening unit of this invention during a sharpening operation.

Figure II is a view on an enlarged scale looking down upon the sharpening unit and further showing its position relative to the knife and the gauge plate.

Figure III is an elevational View of the sharpening unit taken along the line III-Ill of Figure II.

Figure IV is an elevational view of the grinding mechanism of the sharpening unit taken substantially along the line IVIV of Figure II.

Figure V is an isometric View of the spindle arrangement which is typical of both the grinding and honing mechanisms.

Figure V1 is an elevational view with parts broken away and parts in section of the storage location for the sharpening unit when the unit is detached from the gauge plate.

Referring to Figure I, a slicing machine of the general type in which the instant invention is shown consists of a housing 1 above which lies an inclined rotary circular knife 2. Overlying the face of the knife is a knife guard plate 3 against which a substance being sliced rests after it has passed the cutting edge of the knife 2. Lying in a plane substantially parallel to the plane of the guard plate 3 and adjacent the cutting edge of the knife 2 is a gauge plate 4. The gauge plate 4 is laterally adjustable with respect to the plane of the knife 2 to condition the slicer for cutting slices of difierent thicknesses.

A carriage 5 reciprocates along one side of the housing 1 on a track 6 to carry the substance to be sliced past the cutting edge of the knife. A V-shaped trough or substance support '7 constitutes the upper portion of the carriage 5 and is inclined to the housing 1 to permit gravity feeding of the substance carried thereby.

A knife sharpening unit 8, when mounted to sharpen the cutting edge of the knife 2., is detachably secured to the gauge plate 4 by means of a thumb screw 9 which passes through a slotted portion 19 of the gauge plate and is threaded into an upright frame 11 of the unit 8.

The frame 11 has a hat base portion 12 which rests against the gauge plate 4, and further has a flange or lip 13 projecting downwardly from one side of the base portion to bear against the lower edge of the gauge plate to correctly position the unit 8.

Mounted on opposite sides of the upright frame 11 and spaced from each other are an adjustable hone arm 14 and an adjustable grinder arm 15. The arm 14 is provided with slots 14:: and the arm 15 is provided with slots 15a to permit adjustment of the arms 14 and 15 with respect to the blade.

The hone arm 14 is formed with a forwardly and upwardly projecting bifurcated portion 16 through the legs of which is journaled a pin 17 to support one end or and provide a pivot for a yoke-shaped finger-depressible lever 18 of the second order.

A spindle 19 with its axis perpendicular to the gauge plate 4 is rotatably mounted through a slidable sleeve hearing 20 positioned in the hone arm 14. A honing wheel 21 is fastened to the lower end of the spindle 19 by means of a screw 22.. In the instant invention, it is preferable that the sleeve bearing 20 in which the spindle 19 rotates be slidable, but not rotatable in the hone arm 14. Rotation of the bearing 20 is prevented by forming its upper portion as a square head 23, two sides of which bear against side walls 24 of the lever 18.

Iuxtaposed to the square head 23 of the bearing 28 is a trunnion block 25 with its edges coextensive with the edges of the square head. The block 25 is drilled to permit passage of the spindle 19 therethrough. A pair of laterally disposed trunnion pins 26 project from the block 25 and are journaled in the side walls 24 of the lever 18 substantially midway between the levers ends. A collar 27 is pinned to the uppermost end of the spindle 19 to retain the trunnion block 25 and the bearing 29 between said collar and a shoulder 23 of the spindle.

The honing wheel 21 is engaged with the rotating knife 2 of the machine by pressing downwardly on the lever 18 at its end opposite that through which the pin 17 is journaledh The lever 18 is pivoted on the pin to move the co-operating trunnion block 25, the sleeve bearing 20, the spindle 19, and the honing wheel 21 downwardly toward the upper side of the cutting edge of the knife. The spindle 19, when the honing wheel contacts the rotating knife 2, rotates in the sleeve bearing and trunnion block 25. The latter two members, however, are unable to rotate, their square sides being held against rotation by the side walls 24 of the lever 18.

The honing wheel 21 may be held in contact with the knife 2 as long as desired, and when the lever 18 is released, it is returned to its original inactive position by a return spring 29 located on the pin 17.

A shroud 30 is fastened to the spindle 19 at its lower end just above the honing wheel 21 to prevent abrasive dust from the honing wheel from gaining access to the spindle. Figure IV illustrates a shroud which is rotatable with the spindle.

A dust shield 31 is fastened to the hone arm 14 and extends substantially around the shroud 30 to further protect the spindle 19 from dust.

The grinding mechanism is substantially similar to the honing mechanism. It comprises a yoke-shaped finger-depressible lever 32 of the first order pivoted at its center on a pin 33 which extends through legs of a bifurcated portion 34 extending rearwardly and upwardly from the grinder arm 15. A trunnion block 35 similar to the trunnion block 25 is journaled in the side walls 36 of the lever 32 opposite the end of the lever which is depressed. Movement of the trunnion block 35 causes a corresponding movement of a sleeve bearing 37, a spindle 38, a grinding wheel 39, a shrould 40, and a collar 41 which co-operate therewith. It will be noticed that the axis of the spindle 38 is inclined with respect to the gauge plate 4. This accommodates proper engagement of the grinding wheel 39 with the beveled underside 42 of the knife 2.

Since the lever 32 is pivoted at its center, depression of said lever will engage the grinding wheel 39 with the knife by upward movement of the spindle 38, said spindle being so positioned by upward movement of the trunnion block 35 journaled in the side walls 36 of the lever 32.

It can be seen therefore, that both wheels 21 and 39 are engaged with the knife 2 by downward pressure on their respective levers although each approaches and contacts the knife from opposite directions. Also, since the honing mechanism and grinding mechanism are independent from one another, they may be operated separately or simultaneously, as desired.

When the sharpening unit 8 is not attached to the gauge plate 4 in operative position, it is stored in a bowllike hollow portion 43 of the carriage 5 in an inverted position on a bracket 44 attached inside the carriage substantially as shown in Figure VT. By removing a cover 45 of the hollow portion 43, the unit 8 may be attached to the bracket 44 with the thumb screw 9 fitting in a slot in a manner similar to that in which the unit is positioned on the gauge plate 4. The thumb screw 9 is then tightened and the cover 45 replaced. The sharpening unit 8 remains in the hollow portion 43 of the carriage 5 until it is again necessary to sharpen the knife 2.

Operation Let us assume that a grocer wishes to sharpen the knife of his commodity slicer, it having appeared a little dull during the last slicing operation. He would proceed to remove the sharpening unit 8 from its storage position in the carriage 5 by removing the cover 45, loosening the thumb screw 9, and withdrawing the unit from the bracket 44 and the hollow portion 43 of the carriage.

Before the unit 8 can be placed in its operative position on the gauge plate 4, the gauge plate must be moved to 'its lowermost position by rotating a gauge plate knob (not shown).

The sharpening unit 8 is then attached to the gauge plate 4 by fitting the thumb screw 9 into the slotted portion 10 in the lowerright-hand corner of the gauge plate. Proper alignment of the unit 8 in operative position is accomplished by placing the lip 13 of the base portion 12 of the unit snugly against the lower edge of the gauge plate. By tightening the thumb screw 9, the unit 8 is firmly attached to the gauge plate ,4 and the sharpening operation is ready to begin.

Rotation of the knife 2 is necessary in order to sharpen it with the instant invention. The knife is operatively connected to a motor (not shown) in the housing 1. A toggle switch (not shown) permits current to flow to the motor. When said toggle switch is turned on, the motor commences to operate and the knife 2 begins to rotate.

If it is desired to both grind and hone the knife, the

sharpening may take place in one of two ways. The grinding wheel 39 may be engaged with the beveled underside 42 of the cutting edge of the knife 2 by pressing downwardly on the lever 32. As the wheel 39 contacts the knife, rotation of the knife causes said wheel, its spindle 38, and the other rotating parts to rotate in a direction opposite that in which the knife 2 rotates. The knife of the instant invention rotates counter-clockwise, thereby producing a clockwise rotation in the grinding wheel 39.

As the grinding operation progresses, a wire edge is turned upward on the cutting edge of the knife. The lever 32 is then released and the lever 18 is pressed downwardly to engage the honing wheel 21 with the upper side of the edge of the knife 2.

The honing wheel 21 also rotates clockwise upon engagernent with the knife 2, and acts to turn down the wire edge raised by the grinding operation. Here is a decided advantage which finger-engageable sharpening mechanisms have over other means of engaging the wheels with the knife. A sense of touch on the lever 18 can tell the operator exactly when the wire edge has been turned down and the knife 2 is as sharp as possible. Prior art devices which were not finger-engageable often turned down the wire edge too far by too much honing and further created another wire edge on the underside of the knife, since the operator could not feel when the knife was correctly sharpened. Turning a wire edge downward necessitated another grinding operation, and consequently another honing operation. From the standpoint of length of life of the blade, it can easily be seen that the life of a blade sharpened with the instant invention would be considerably longer than one sharpened with prior art sharpening devices of the spring or cam engageable type.

Another method of sharpening when both grinding and honing of the knife 2 are desired is to press downwardly on both levers 18 and 32 simultaneously, thereby engaging both the grinding and honing wheels with the knife. In this way, a wire edge is not created, since both wheels work toward a common edge. After a short period, the pressure on the levers is lessened until both wheels are removed from engagement with the knife. A very sharp cutting edge is produced by this method. Prior art devices of the spring-engageable type had no means by which the pressure of the wheels against the knife could be lessened.

Quite often a grocer wishes merely to hone his knife slightly. In that case, the honing mechanism alone is operated.

When the operator feels that his knife is sharp, he can test it by any of the several methods which need not be expounded here. If, upon testing the knife, he feels it has been sharpened enough, he can proceed to remove the sharpening unit, replace it on the bracket 44 in the hollow portion 43 of the carriage 5, replace the cover 45, and commence his slicing of a commodity.

The embodiment of my invention herein shown and described is to be regarded as illustrative only and it is to be understood that the invc ntion is susceptible to variation, modification, and change within the spirit and scope of the snbjoined claims.

I claim:

1. A sharpener for the rotary knife of a commodity slicing machine comprising, in combination, a grinding wheel adapted to engage one side of the rotary knife, a honing wheel adapted to engage the other side of the rotary knife, means for rotatably supporting the wheels, and finger-depressible means for independently engaging each wheel with the rotary knife, said finger-depressible means comprising a lever of the first order operatively connected to the grinding wheel and a lever of the second order operatively connected to the honing wheel, whereby depression of the levers in the same direction will cause the Wheels to engage the rotary knife from opposite directions.

2. A sharpener according to claim 1 wherein the levers are adjacently located, whereby the levers may be depressed by two fingers of one hand.

3. A sharpener according to claim 1 which is detachably mountable on the machine.

4. A sharpener for the rotary knife of a commodity slicing machine comprising, in combination, a frame, a hone arm adjustably attached to the frame, a grinder arm adjustably attached to the frame, a hone spindle rotatably mounted through a slidable sleeve bearing in the hone arm, a honing wheel fixed to the end of the hone spindle nearest the rotary knife, a hone pin on the hone arm, a hone lever having an end pivoted on the hone pin and attached between its ends to the slidable sleeve bearing, a grinder spindle rotatably mounted through a slidable sleeve bearing in the grinder arm, a grinding wheel fixed to the end of the grinder spindle nearest the rotary knife, a grinder pin on the grinder arm, a grinder lever having an end pivotally attached to the grinder spindle and pivoted between its ends on the grinder pin, whereby movements of the free ends of the levers in directions generally toward the plane of the rotary knife engages the wheels with the rotary knife from opposite directions.

5. A sharpener according to claim 4 wherein the levers are adjacently located, whereby the levers may be depressed by two fingers of one hand.

6. A sharpener according to claim 4 which is detachably mountable on the machine.

References Cited in the file of this patent UNITED STATES PATENTS 1,060,916 Luschka May 6, 1913 1,483,878 Hand Feb. 19, 1924 1,772,704 Campbell Aug. 12, 1930 2,030,197 Campbell Feb. 11, 1936 2,486,797 Meyer Nov. 1, 1949 FOREIGN PATENTS 609,867 Great Britain Oct. 8, 1948 988,143 France Apr. 25, 1951

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