US2725698A - Method of sharpening endless slicer blades - Google Patents

Description

Dec. 6, 1955 HlLL METHOD OF SHARPENING ENDLESS SLICER BLADES Filed April 28, 1952 mu m Nn T M A r 0 GM M m United States Patent METHOD OF 'SHARPENING ENDLESS SLICER BLADES Gordon Hill, Bettendorf, Iowa, assignor, by mesne assignments, to Bettendorf Bakery Equipment Qompany, Bettendorf, Iowa, a corporation of Iowa Application April 28, 1952, Serial No. 284,741

2 Claims. (Cl. 51-285) This invention relates to a method of sharpening endless slicer blades in place in a bread slicing machine and has for its object to provide a method by means of which the band blades of a bread slicing machine may be quickly and easily sharpened without removing them from the machine.

Endless band blade bread slicing machines are commonly provided with vertically spaced pulleys over which the bands run and intermediate the pulleys they have one or more transverse rows of blade guides for holding the blades in parallel planes and equally spaced apart in the slicing zone. Usually two vertically spaced rows of blade guides are provided, one above and the other below a slicing zone so that the blades are held parallel and against relative lateral movements while passing through the bread.

The present invention provides a method of sharpening the blades of a bread slicing machine while the machine is running at operating speed by inserting a small diameter cylindrical grinding wheel between the blades adjacent one of the rows of blade guides and preferably in the slicing zone between the upper and lower sets of guides while the machine is running at operating speed, driving the grinding wheel and engaging it with the cutting edge of the adjacent blade that is traveling in the direction opposite that of the blade engaging portion of the grinding wheel so that the relative speeds of travel of the abrasive surface and blade is the sum of the peripheral speed of the grinding wheel and the linear speed of the blade. The speed of rotation of the grinding wheel is such that the speed of its periphery relative to the work is sufiicient to obtain effective grinding action.

In order to elfectively grind both sides of the cutting edges of the blades, the direction of the grinding wheel is reversed when it is shifted from one side of the blade to the other to provide proper relative travel of the abrasive surface with respect to the blade.

In order to conveniently position the grinding wheel with respect to each of the band blades, a combined guard and tool rest is provided which has equally spaced concave tool seats the centers of which are alined with the cutting edges of each of the band blades.

The grinding operation is preferably performed with a portable grinding unit which comprises a small reversible electric motor having a grinding wheel attached to its shaft. The motor housing is of a size to provide a convenient hand grip and has an end portion adapted for engagement in the concave seats of the tool rest so that the grinding wheel can be firmly held in proper position with respect to each of the band blades.

Reference should be had to the accompanying drawings forming a part of this specification, in which:

Figure l is a fragmentary perspective view showing the combined guard and tool rest in place on the feed bed of a slicing machine, with the grinding unit positioned for grinding one side of a cutting edge of one of the band blades;

Fig. 2 is a fragmentary side elevation of the machine with the combined guard and tool rest in place thereon;

Fig. 3 is a front elevation of the combined guard and tool rest;

Fig. 4 is a vertical section taken on the line indicated at 44 in Fig. 3;

Fig. 5 is a fragmentary sectional view showing the grinding wheel in engagement with the blade; and

Fig. 6 is a fragmentary side elevation of a cutter blade.

in the accompanying drawings a bread slicing machine is shown diagrammatically, the machine having upper and lower pulleys 1 and 2, the lower of which is driven by suitable means such as a motor 3. A series of band blades 4 run over the pulleys 1 and 2 and are crossed between the pulleys. Upper and lower sets of adjustable blade guides 5 and 6 are provided above and below the crossing zone. The upper and lower rows of blade guides serve to hold the portions of the blades between the guides in parallel planes and equally spaced. Bread to be sliced is fed between the upper and lower guides 5 and 6 and is advanced through the slicing zone on a feed bed 7 the top surface of which is in the plane of the top surfaces of the blade guides 6. The bread is fed to the blades by means of a feed conveyor 8 and the sliced loaves pass from the slicer to a delivery conveyor 9.

The blade adjusting and guiding means and the means for guiding the bread into the slicer are not described in detail since these features are well known in the art. For example, the slicing machine may be constructed in accordance with the disclosure of the patent to Kottmann et al. 2,297,710, October 6, 1942.

As shown in Fig. 5, the guide members are provided with narrow slots 1t through which the blades pass, which serve to hold the blades in parallel planes in the slicing zone. To sharpen the blades 4 without removing them from the machine the bread guides associated with the bed 7 are removed and a combined guard and tool rest 11 is mounted on the bed. The guard 11 is disposed in front of the band blades facing the cutting edges thereof and parallel to the row of band guides 6. For securing the combined guard and tool rest 11 in place on the bed 7, it is provided with attaching brackets 12 which have hooks 13 that engage with the bed 7 at the edge of a slot 14 in the bed through which the flights of the feed conveyor 3 pass. The brackets 12 rest on the top face of the bed 7 and serve to position the guard 11 with respect to the slicer blades. The guard 11 is provided with a longitudinal slot 15 through which access to the blades is provided for a suitable grinding tool, and the bottom edge of the slot 15 is formed to provide regularly spaced concave seats 16. The spacing of the seats 16 is such that the band blades may be adjusted to aline a portion of the cutting edge of each with the central portion of one of the seats 16.

The grinding operation is performed with a grinding wheel 17 of cylindrical form and of small diameter. The grinding wheel 17 is detachably secured to the shaft of a small reversible electric motor 18, the motor 18 and grinding wheel 17 forming a portable grinding unit which can be easily manipulated to bring the grinding wheel into engagement with the individual band blades.

In order to enable the operator to hold the grinding wheel in proper position during the grinding operation, the housing of the motor 18 is of a size suitable to provide a hand grip and is formed to provide a tubular end portion 19 which is adapted to rest in any one of the concave seats 16 of the tool rest and a shoulder 20 engageable with the outer face of the tool rest to limit the inward movement of the grinding wheel.

To grind the band blades of the slicing machine the bread guides are removed and the combined guard and tool rest 11 is secured in place on the feed bed 7 as shown in Fig. 1. The feed conveyor 8 is disconnected from its driving means and the motor 3 is operated to drive the band blades 4 at the speed at which they are normally driven during operation of the slicing machine. The grinding unit is then positioned with the extension 19 of the motor housing in engagement with one of the seats 16 of the tool rest and with the grinding wheel 17 beside the cutting edge of the blade that is alined with the seat upon which the extension 19 rests.

The grinding wheel may be initially positioned either to the right or to the left of the blade to be ground but the motor 18 will always be operated to drive the grinding wheel in the direction in which the portion of its periphery which is to engage the blade will move in a direction opposite that in which the blade with which it is to engage is moving. After the grinding wheel 17 has been positioned and after the motor 18 has been started in the proper direction, the grinding unit may be rocked on the seat 16 with which it engages to bring the grinding wheel to its grinding position where it engages the blade as shown in Fig. of the drawing. By successively engaging the grinding wheel with the edges of the band blades moving past the tool rest all of the blades of the slicing machine can be quickly and easily sharpened without removing them from the machine.

In order to avoid frequent starting and stopping of the grinding wheel driving motor, the blades are preferably all ground on one side by positioning the grinding unit on successive seats with the grinding wheel to the right or to the left of the successive blades while the grinding wheel is being driven in the proper direction for grinding the blades to which the wheel is presented, after which the direction of rotation of the grinding wheel is reversed and the blades are ground on their opposite sides.

The grinding wheel must be of small diameter in order to enable it to be inserted between the blades of the slicing machine and because of its small diameter a high speed of rotation is required to obtain a linear speed of its periphery sufficient for efficient grinding action. By so controlling the operation of the grinding wheel that its peripheral blade engaging portion travels in a direction opposite that of the blade with which it engages, the speed of the abrasive surface of the wheel with respect to the blade with which it engages is greatly increased, making it possible to obtain rapid grinding action with a motor driven grinding wheel of a diameter small enough to be received between the adjacent band blades of a bread slicing machine.

In slicing machines in which the band blades are crossed the grinding wheel may be positioned between corresponding runs of adjacent bands which are spaced apart double the thickness of the slices to be cut and K which have their cutting edges close to the tool rest 11. The grinding wheel receiving space is twice the thickness of the slices to be cut, usually about one inch, and the grinding wheel may be of any size that will permit it to be conveniently manipulated.

The tubular portion 19 is slidable on the seats 16 of the tool rest, so that the grinding wheel 1.7 may be adjusted inwardly or outwardly with respect to the tool rest to engage different portions of the periphery of the grinding wheel with the band blades so that wear on the grinding wheel may be uniformly distributed and the wheel may be used longer before it is necessary to clean it.

Because of the rapid travel of the blades with respect to the grinding wheel, only a short period of time is required to sharpen each of the blades.

It is to be understood that in accordance with the provisions of the patent statutes, variations and modifications of the specific devices herein shownand described may be made without departing from the spirit of the invention.

What I claim is:

1. The herein described method of sharpening an endless band blade in place in a bread slicing machine that has a plurality of endless band blades and regularly spaced parallel guides that hold the blades in parallel planes in the slicing zone which comprises driving said slicing machine at its operating speed, inserting a cylindrical grinding wheel having a diameter less than the width of the space between said blade and the next adjacent blade on one side thereof into said space near said guides, driving said grinding wheel in the direction in which the peripheral portion thereof adjacent said blade moves in a direction opposite that of said blade, moving said grinding wheel laterally to engage a portion of its periphery with the adjacent side of the cutting edge of said blade, holding said grinding wheel in engagement with said blade with its axis at a small angle to the plane of said blade, disengaging the grinding wheel, reversing the direction of rotation of the wheel and applying the wheel to the opposite side of the cutting edge of said blade with its axis disposed at a reverse inclination with respect to the plane of said blade.

2. The herein described method of sharpening a sealloped endless band cutter blade in place in a bread slicing machine that has spaced pulleys, a series of scalloped endless slicer blades running over said pulleys and crossed between said pulleys, and a row of blade guides extending transversely of the blades intermediate said pulleys for holding the portions of said blades adjacent said guides in regularly spaced parallel planes which comprises: driving said pulleys and the blade carried thereby at their operating speed, inserting a cylindrical grinding wheel having a diameter less than twice the distance between said adjacent parallel planes into the space between one of said scalloped blades and the next adjacent blade on one side thereof, driving said grinding wheel in the direction in which the peripheral portion thereof adjacent said blade moves in a direction opposite that of said blade, moving said grinding wheel laterally to engage a portion of its periphery with the adjacent side of the cutting edge of said scalloped blade, holding said grinding wheel in engagement with said blade with its axis at a small angle to said parallel planes, disengaging the grinding wheel, reversing the direction of rotation of the wheel, and applying the wheel to the opposite side of the cutting edge of said scalloped blade with its axis disposed at a reverse inclination with respect to said parallel planes.

References Cited in the file of this patent UNITED STATES PATENTS 396,553 Fowle Jan. 22, 1889 1,520,817 Harris Dec. 3.0, 1924 1,551,167 Orlow Aug. 25, 1925 1,706,483 Corbett Mar. 26, 1929 1,911,974 Shelton May 30, 1933 1,963,449 Rubin June 19, 1934 1,981,944 Brostrom Nov. 27, 1934 2,002,812 Hansen May 28, 1935 2,073,861 Wolf Mar. 16, 1937 2,148,457 Grossarth Feb. 28, 1939 2,225,600 Kottmann Dec. 17, 1940 2,621,454 Callahan Dec. 1.6, 1952

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