US2703950A - Sickle grinding machine - Google Patents

Description

March 1955 E. NORWOOD ET AL 2,703,950

sIcxLE GRINDING MACHINE Filed April 30, 1951 2 Sheets-Sheet 1 will /7 20 I J2 i ZZLJVorwood L.fi.3nemman INVENTORS,

BY I ATTORNEYS- March 15, E NORWOOD ETAL 51cm; GRINDING MACHINE Filed April 30, 1951 2 Sheets-Sheet 2 EL. JVorwoad Zflfinemaman INVENTORS ATTORNEYS United States Patent '0 2,703,950 SICKLE GRINDING MACHINE Ernest L. Nor-wood and Lloyd D. Brennaman, Ewing, Nebr.

Application April 30, 1951, Serial No. 223,714

2 Claims. (Cl. 51-125) This invention relates to a machine designed for grinding blades of sickle bars, the primary object of the invention being to provide a machine which will sharpen and recondition the blades of a sickle bar with a be'vel corresponding with the beveled cutting edges of new sickles.

An important object of the invention is to provide a machine of this character on which a sickle bar may be secured in such a way that the blades of the sickle bar may be engaged by the side faces of the grinding stones of the machine to properly grind the desired bevel or cutting edges of the blades.

A still further object of the invention is to provide a sickle grinding machine wherein the grinding stones of the machine may be adjusted to various angular positions with respect to the blades of the sickle bar being conditioned for insuring accurate grinding.

Another important object of the invention is to provide a sickle grinding machine including a vertically swinging grinding head, means being provided for automatically moving the grinding head to a position away from the sickle bar being ground, when the pressure on the grinding head necessary to hold the grinding stones to their work, has been relieved.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts, hereinafter more fully described and pointed out in the claims, it; being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawings:

Figure 1 is a front elevational view of a sickle grinding machine constructed in accordance with the invention illustrating a sickle bar as mounted thereon.

Fig. 2 is a plan view thereof.

Fig. 3 is an end elevational view of the machine with the grinding head moved to its inactive position.

Fig. 4 is a plan view illustrating the sickle support as swung to a position for engagement by one of the grinding stones of the machine.

Fig. 5 is a sectional view taken on line 5-5 of Fig. 3.

Referring to the drawings in detail, the machine comprises the stand indicated generally by the reference character 5, the stand comprising the legs 6 and post 7 rising therefrom. Secured at the upper end of the post 7 is the tubular section 8 which is provided with openings 9 adapted to register with openings 10 of the hollow post 11 that extends downwardly from the forward end of the adjustable grinding head support 12. A pin 13 is provided and is adapted to be extended through the aligning openings of the tubular section 8 and hollow post 11, securing the grinding head support in various angular positions with respect to its work.

Pivotally mounted on the grinding head support, is the grinding head 14 which is in the form of a pair of spaced arms connected at their forward ends where the bearings 15 are provided, in which the grinding stone shaft 16 operates, the ends of the grinding stone shaft 16 extending beyond the bearings, as clearly shown by Fig. 4 of the drawings. The grinding stones are indicated by the reference character 17 and are secured at the ends of the grinding stone shaft 16. The grinding head also provides a support for the electric motor 18, which is provided with the pulley 19, over which the belt 20 operates, the belt ice 20 also operating over the sheave 21 which is secured to the shaft 16, so that rotation of the shaft 16 and grinding stones 17 will be provided by the operation of said motor.

Extending from one end of the grinding head 14, is the arm 22, to which one end of the coiled spring 23 is secured, the spring 23 having its opposite end secured to the post 7 through the medium of the hook 24. This spring 23 is so tensioned that under normal conditions or when the grinding head is not in use, the grinding head will be tilted rearwardly to the position as shown by Fig. 3 of the drawing, or away from its work. It will be obvious that with slight pressure directed to the grinding head, the grinding head will be moved downwardly bringing the grinding stones into contact with the blades of the sickle bar being sharpened.

Extending forwardly from the tubular section 8 of the machine, are the spaced bolts 25, to which the vertical supporting bar 26 is secured, the upper end of the supporting bar 26 being attached to the horizontal supporting member 27 which includes a wide bar of inverted V-shape in cross section, to which the rods 28 are connected at their outer ends, the rods 28 having their inner ends connected to the vertical supporting bar 26.

The support for the sickle bar indicated at 29 being sharpened, is in the form of a carriage 30 of inverted V-shape construction fitted over the horizontal supporting member 27 to slide longitudinally thereof. The carriage or support 30 is provided with clamps 31 within which the sickle bar 29 to be ground is secured as by means of set screws 32.

In the use of the grinding machine, the sickle bar to be ground is positioned in the clamps 31 and is secured within the clamps by the set screws 32. The grinding head support is now moved to a position to bring one of the grinding stones thereof into engagement with one edge of one of the blades of the sickle bar. The pin 13 is now positioned to hold the brinding head support in its adjusted position. The grinding stone is now set in motion and the right hand cutting edge of the blade is engaged by the left side face of the stone grinding or sharpening the right hand cutting edge of the blade. After the sharpening of the blade edge, the grinding head is elevated and the carriage or support 30 is moved a distance to bring the right hand cutting edge of the adr jacent blade opposite to the grinding stone, which has been moved adjacent to the sickle bar. This operation is continued until the right hand edges of all of the blades of the sickle bar have been properly ground.

The grinding head is now lifted and adjusted or rotated to bring the opposite grinding stone to a position for engagement with the left hand cutting edges of the blades, and a pin 13 is positioned through the aligned openings of the post 8 and hollow post 11, thereby securing the grinding head against movement in a horizontal plane sliding the sickle bar carriage along its support, it is obvious that the left hand cutting edges of each sickle bar blade may be properly ground. After the grinding operation it is obvious that the sickle bar may be readily removed and another sickle bar positioned within the carriage for grinding.

In view of the foregoing, it is believed that the construction and operation of the sickle bar grinding machine will be obvious, and that further detailed description is unnecessary.

Having thus described the invention, what is claimed is:

1. In a sickle grinding machine, a stand, a support mounted on the stand comprising a wide horizontal bar of inverted v-shape cross section, an inverted V-shaped carriage on which the sickle bar being ground is mounted for sliding movement longitudinally of said support, a grinding head support mounted on the stand for pivotal movement in a horizontal plane, a grinding head mounted on said grinding head support, a power shaft mounted on the grinding head, normally disposed in parallel spaced relation with said sickle bar support, a grinding stone secured on each end of said power shaft, said stones adapted to be manually moved into contact with cutting edges of the blades of the sickle bar being ground, and means for normally swinging the grinding head upwardly away from the sickle bar with respect to the grinding head support.

2. A sickle grinding machine comprising a stand including a vertical post, a tubular member secured to the upper end of said post, a clamp secured to said tubular member adapted to clamp a sickle bar in horizontal position with the blades thereof disposed upwardly, a grinding head support, a hollow post depending from said grinding head support and rotatably fitted in the tubular member, said tubular member and hollow post having aligning openings, a pin extending through said aligning openings securing the grinding head support in its positions of horizontal adjustment, a grinding head pivotal- 1y mounted on the grinding head support for vertical swinging movement, grinding stones mounted on the grinding head adapted to grind the blades of the sickle bar mounted in the clamp, a spring connected between the grinding head and stand normally biasing the grinding head and stones upwardly away from the sickle bar, 1

and means for operating the grinding stones.

References Cited in the file of this patent UNITED STATES PATENTS Scott Oct. 13, Hefft Aug. 15, Dutton Aug. 4, Dutton Aug. 15, Gilson June 25, Fachman Oct. 5, Cooney May 1, Brown et a1. Apr. 4, Cotfeen Oct. 25,

FOREIGN PATENTS Germany May 24, France Dec. 12,

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