US2717477A - Sickle bar grinder - Google Patents

Description

Sept. 13, 1955 MOULTON SICKLE BAR GRINDER 2 Sheets-Sheet 1 Filed June 12, 1953 INVENTOR A uvpew L. M001. roxv BY yrsm ,20 HFL ATTORNEYS p 13, 1955 L. MOULTON 2,717,477

SICKLE BAR GRINDER Filed June 12, 1955 2 Sheets-Sheet 2 66' INVENTOR A/IVDi/V A, Mil/L 77A United States Patent This invention relates to sickle bar grinders and more particularly to a grinder for grinding the cutting edges of the blade sections of sickle bars for mowing machines and similar implements.

It is among the objects of the invention to provide an improved sickle bar grinder having a rigid frame on which a sickle bar to be ground is rigidly supported and a grinding wheel carriage movable along the frame to the different blade sections of the associated sickle bar, so that the grinder has a total length not materially in excess of the length of the longest sickle bar to be ground thereon and thus, requires a minimum of operating space; which provides freedom of manually controlled movement of the grinding wheel toward and away from the blade section edges along the blade section edges, so that these edges can be accurately ground to a sharp and straight condition; which provides adjustment of the sickle bar holding means to compensate for wear of the grinding wheel; which can be provided in a movable form having an integrally incorporated supporting stand or in a stationary form and mounted on a fixed support, such as a building wall; and which is simple and durable in construction, economical to efi'icient in use. v

Other objects and advantages will become apparent from a consideration of the following description and the appended claims in conjunction with the accompanying drawings wherein:

Figure 1 is a front elevational view of a sickle bar grinder illustrative of the invention;

Figure 2 is a transverse cross sectional view on an enlarged scale on the line 22 of Figure 1;

Figure 3 is a fragmentary front. elevational view of the grinder on an enlarged scale showing structural details of the grinder;

Figure 4 is a top plan view of the fragmentary portion of the. grinder illustrated in Figure 3;

Figure 5 is a transverse cross sectional view on the line 55 of Figure 3;

Figure 6 is a fragmentary perspective view of the grinder frame showing structural details thereof; and

Figure 7 is an end elevational view of the frame showing a modified form of grinder frame.

With continued reference to the drawings, the grinder comprises a frame, generally indicated at 10, including a pair of posts 11 and 12 disposed in upright and spaced apart and substantially parallel relationship to each other, a guideway structure or track 13 extending along the bottom ends of the posts and rigidly secured thereto, a rail 14 extending past the upper ends of the posts and disposed above and parallel to the guideway structure 13,

manufacture, and effective and and arms 15 and 16 connected each at one end to the rail 14 at spaced apart locations along the rail and projecting perpendicularly in the same direction from the rail. The arm 15 is pivotally connected at its end remote from the rail 14 to the upper end of the post 11 by a pivot bolt 17 which can be tightened to lock the arm in selected positions of angular adjustment relative to the associated post and the arm 16 is secured to the post 12 by a similar bolt 18.

Screw clamps 20 to 23 inclusive, are mounted on the rail 14, one at each end of the rail, and the other two at locations spaced apart along the length of the rail and project from the rail in a direction away from the side of the rail remote from the posts 11 and 12, and these screw clamps rigidly secure a sickle bar 24 to the rail with the blade sections 25 of the sickle bar from the side of the rail remote from the posts 11 and 12 and substantially horizontally disposed, as illustrated in Figure 5.

The guide structure 13 is an elongated bar or rail of right angular cross sectional shape and is mounted on the posts 11 and 12, so that the legs 26 and 27 thereof are inclined symmetrically outwardly and downwardly from the edge of the member at which the corresponding edges of the legs are joined.

A carriage 30 of right angular cross sectional shape is disposed on the guide structure 13 and carries antifriction rollers 31 to 34 inclusive, one at each corner thereof, which rollers bear on the upper surfaces of the legs 26 and 27 of the guide structure 13 near the outer edges of these legs to support the carriage on the guide structure for free translational movement along the guide structure. Brackets 35 and 36 are mounted on the upper surfaces'of the angularly disposed sides of the carriage 30 and project outwardly beyond the outer edges of the corresponding carriage sides, and peripherally grooved rollers 37 and 38 are journaled on the outer ends of these brackets and engaged the outer edges of the legs 26 and 27 of the guide structure 13 to hold the carriage in place on the guide structure.

It will be noted that the posts 11 and 12 are provided at their lower ends with hook formations having upwardly directed terminal portions 40 and 41 which extend upwardly to the under surface of the guidestructure 13 and are rigidly secured to the guide structure by suitable means, such as welding, to rigidly secure the posts to the guide structure.

Apertured lugs 43 and 44 extend transversely of and upwardly from the carriage 30 at locations spaced apart along the carriage and are disposed substantially parallel to each other. An upright structure including a rotatable grinding wheel and power means operatively connected thereto is superimposed upon the carriage 30 and is connected at its lower end to the carriage for rocking movement about a horizontal axis toward and away from the sickle bar supporting means or rail 14. Specifically, an L-shaped bracket, generally indicated at 45, has a base portion 46 of rectangular shape disposed between the lugs 43 and 44 and pivotally secured to these lugs by rivets 47 and 48 respectively, for rocking movements of the bracket relative to the carriage about an axis disposed parallel to the guide structure 13. A stop or abutment 49 is mounted on the side of the carriage 30 remote from the posts 11 and 12, and extends upwardly from the carriage to engage the bottom edge of the bracket base 46 to limit rocking movements of the bracket in a direction away from the rail 14 for a purpose which will presently appear. p

A standard 50 is secured to the base 46 at the side of the base remote from the posts 11 and 12 and extends perpendicularly upwardly from the base to a location slightly below the level of the rail 14. An arm 51 is pivotally secured atone end to the standard 50 at a location immediately above the bracket base 46 by a rivet or bolt 52 extending transversely through the bracket and throughthe adjacent end of the arm and this arm extends from the standard 50 toward a plane including the longitudinal center lines of the frame posts 11 and 12 of the grinder. An electric motor 53 is mounted on the arm projecting 51 and is connected to a power source by an extension cord of sufiicient length to permit movement of the motor with the bracket and carriage 30 longitudinally of the guide structure 13 from one end to the other end of the guide structure.

A second arm 54 is pivotally connected at one end to the upper end of the standard by a pin or rivet 55 extending transversely through the standard and the corresponding end of the arm and this arm also projects from the standard toward a plane including the longitudinal center lines of the frame posts.

A bearing sleeve 56 extends transversely through and is secured in the arm 54 at the end of this arm remote from the standard 50, and a shaft 57 extends through and is journaled in the bearing sleeve 56 for rotation about an axis parallel to the guide structure 13. A double be veled grinding wheel 58 is mounted on the shaft 57 at one end of the bearing sleeve 56 and a belt pulley 60 having a diameter less than the minimum diameter of the grinding wheel 58 is mounted on the other end of the shaft 57. A belt wheel 61 is mounted on the shaft 62 of the motor 53 and a V-belt 63 drivingly connects the motor belt pulley 61 to the grinding wheel belt pulley 60.

' An adjustable length link 65 is pivotally connected at one end to the arm 54- intermediate the length of this arm and is pivotally connected at its other end to the arm 51 intermediate the length of the latter arm for varying the distance between the arms 51 and 54 and thereby maintaining the drive belt 63 under the proper tension. A handle 66 is secured at its lower end to the standard 50' near the upper end of the standard, and projects upwardly above the upper end of the standard to provide a handle for rocking the bracket 45 about the axis of the pivot pins or rivets 47 and 48 to move the grinding wheel 58 along the cutting edges of the blade section 25 of a cutter bar clamped to the rail 14.

A hand lever 68 is secured at its lower end to the upper arm 54 and extends upwardly from the upper arm in spaced relationship to the handle 66. This hand lever, when moved toward or away from the handle 66, raises or lowers the grinding wheel 58 relative to the cutter bar 24, so that the proper pressure can be manually exerted between the grinding wheel and the blade sections of the sickle bar as the wheel is moved along the cutting edges of the blade sections by rocking the bracket 45.

An angle bracket 70 is secured to the arm 54 at the under side and intermediate the length of this arm, and depends downwardly from the arm, and a compression spring 71 is disposed between the bracket 70 and the adjacent side of weight of the grinding wheel, the bearing sleeve, the grinding wheel shaft and the motor, so that the grinding wheel can be raised with moderate manual effort. The handle 66 and hand lever 68 are so disposed relative to each other, that one hand of an operator can be placed around both of these members and the lever 68 can be moved toward the handle 66 to raise the grinding wheel by merely using the grip of the operators hand in a compressive manner.

The grinding wheel and its supporting carriage can be moved along the guideway structure 13 to successively position the grinding wheel in the notches between ad jacent blade sections of the associated sickle bar, and with the motor 53 in operation, the grinding wheel can be pressed against the beveled sides of the cutting edges of the blade sections with the proper pressure, and moved back and forth along the cutting edges of the blade sections until the cutting edges of the sections are ground to a straight and sharp condition, the arrangement providing a high degree of sensitivity and accuracy for the grinding operation.

' In the form of the invention. shown in Figure 1, legs 72 and 73 are integrally joined at their upper ends to the bottom ends of the frame posts 11 and. 12 respectively, and extend downwardly from the frame posts in longithe standard 50 and counterbalances the tudinal alignment therewith. Base plates 74 and 75 are secured to the bottom ends of the legs 72 and 73 respectively, substantially perpendicular to the longitudinal center lines of these legs, and support the grinder on a horizontal supporting surface, such as the ground or a building floor. This form of the invention is movable and in this form, the grinder may be carried from place to place, as desired. In the arrangement shown in Figure 7, the legs 72 and 73 and the base plates 74 and 75 are omitted, and the posts are provided at locations spaced apart therealong with apertured angle brackets, as indicated at 76 and 77 in Figure 7, and screw fasteners, as indicated at 78 and 79, may be inserted through the apertures in the angle brackets and threaded into a vertical supporting structure, such as a building wall 80, to support the grinder in a stationary position.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative. and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed is:

1. A sickle bar grinder comprising a frame including upright posts disposed in spaced apart relationship to each other, a guideway structure extending along the lower ends of said posts and rigidly secured thereto, a rail extending along the upper ends of said posts and disposed above and parallel to said guideway structure, means mounting said rail on said post for movements of, adjustment of said rail toward and away from said guideway structure, clamps carried by said rail at locations spaced apart therealong for clamping a sickle bar tosaid rail, a carriage mounted on said guideway structure, rollers supporting said carriage on said guideway structure for movement of the carriage longitudinally of the guideway structure, a bracket pivotally mounted on said carriage for rocking movements about an axis sub stantially parallel to said guideway structure and including a base and a standard upstanding from said base, arms pivotally mounted on said standard at locations spaced apart along the latter and extending from said standard toward a plane including the longitudinal center lines of said posts, a double beveled grinding wheel journaled on the uppermost of said arms for rotation about an axis substantially parallel to said guideway structure, a motor mounted on the lowermost of said arms and drivingly connected to said grinding wheel, adjustable length means interconnecting said arms, a handle extending above the upper end of said standard for rocking said bracket on said carriage to move said grinding wheel along the edges of the blade sections of a sickle bar clamped to said. rail, and a lever secured to said uppermost arm and extending. therefrom in spaced relationship to said handle for moving said grinding wheel toward and away from the associated sickle bar blade sections. v

2. A sickle bar grinder comprising spaced posts, means carried by the upper ends of said posts for supporting a sickle bar to be sharpened, a track arranged on one side of and spaced from said posts and extending from one to the other of said posts, a carriage connected to said track for. back and forth movement therealong, an upright structure including an upstanding L-shaped bracket having its short leg connected adjacent its free end to said carriage for rocking movement about a horizontal axis toward and away from said sickle bar supporting means, a motor arranged in superimposed spaced relation with respect to the short leg; of said bracket and carried by the long. leg of said bracket, a rotatable. grinding wheel arranged in parallel superimposed relation with respect to said motor i and carried by the long leg of said bracket and drivingly' connected to said motor, and hand actuable means on the long leg of said bracket adjacent its free end for efiecting the rocking movement of said bracket.

3. A sickle bar grinder comprising spaced posts, means carried by the upper ends of said posts for supporting a sickle bar to be sharpened, a track arranged on one side of and spaced from said posts and extending from one to the other of said posts, a carriage connected to said track for back and forth movement therealong, an upright structure including an upstanding L-shaped bracket having its short leg connected adjacent its free end to said carriage for rocking movements about a horizontal axis toward and away from said sickle bar supporting means, a motor arranged in superimposed spaced relation with respect to the short leg of said bracket and carried by the long leg of said bracket, a rotatable grinding wheel arranged in parallel superimposed relation with respect to said motor and carried by the long leg of said bracket and drivingly connected to said motor, hand actuable means on the long leg of said bracket adjacent its free end for efiecting the rocking movement of said bracket, and spring means operatively connected to the long leg of said bracket and said grinding wheel for biasing said structure toward said sickle bar supporting means.

4. A sickle bar grinder comprising spaced posts, means carried by the upper ends of said posts for supporting a sickle bar to be sharpened, a track arranged on one side of and spaced from said posts and extending from one to the other of said posts, a carriage connected to said track for back and forth movement therealong, structure including an upstanding L-shaped bracket having its short leg connected adjacent its free end to said carriage for rocking movement about a horizontal axis toward and away from said sickle bar supporting means, a motor arranged in superimposed spaced relation with respect to the short leg of said bracket and carried by the long leg of said bracket, a rotatable grinding wheel arranged in parallel superimposed spaced relation with respect to said motor and carried by the long leg of said bracket and drivingly connected to said motor, hand actuable means on the long leg of said bracket adjacent its free end foreflfecting the rocking movement of said bracket, and an upstanding abutment on said carriage and engageable with the short leg of said bracket for limiting the rocking movement of said bracket away from said sickle bar supporting means.

References Cited in the file of this patent UNITED STATES PATENTS 2,456,827 Greeley Dec. 21, 1948 2,482,934 Rainbolt et a1 Sept. 27, 1949 2,486,119 Coifeen Oct. 25, 1949 2,520,210 Howell Aug. 29, 1950 2,582,607 Rinne Jan. 15, 1952 2,654,187 Ferrin Oct. 6, 1953 2,659,184 Mead et a1. Nov. 17. 1953 an upright

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