US2203951A - Sharpening device - Google Patents

Description

June 11, 1940. c. R. ELLIS SHARPENING DEVICE Filed April 29. 1939 2 Sheets-Sheet 1 I'll INS/ENTER. ELLIE HTTUE'NEE June 11, 1940.

c. a. ELLIS SHARPENING DEVICE Filed April 29, 1939 2 Sheets-Sheet 2 INYENTUR.

[1 R- ELLIS Btrr \-m-w HTTURNEH.

Patented June 11, 1940 rarer DFFlCE SHARPENING DEVICE OlarenceRayrnond Ellis, Sausalito, Calif.

. ApplicationAprilZB, 1939, Serial No. 270,857

3 2 Claims.

This invention relates to improvements in sharpening devices and has particular reference to a device for sharpening screwdrivers, and more Cir in the bottom of the screwhead slot.

Acfurther object of this invention is to produce a device of this character which is simple to operate, economical to manufacture and one which will accommodate screwdrivers of various sizes and yet produce a uniformresult, irrespective of the sizeof the screwdriver.

Afurther object isto provide means for limit ing the end grinding actionwhen facing the end of thescrewdriver after the sharpening opera- 1) tion.

. during the course of the following description. ,In the accompanying drawings forming a part of this specification and in which like numerals 5 are employedto designate like parts through the same,

Fig. 1 is a side elevation of my device.

i Fig. 2 is an end elevation looking from the left of Fig. 1.

Fig. 3 is a side elevation showing portion thereof broken away in order to illustrate the mechanism. l

Fig. 4 is a top plan view of Fig. 2.

Fig. 5 is an enlarged fragmentarydetailed view,

5 showing the sharpening operation.

Fig. 6 is. an enlarged fragmentary detailed view, showing the end grinding operation and Fig. ,lis. a fragmentary detailed view, showing the rear arrangement.

Screwdrivers rapidly become bent, burred,

chipped and otherwise. deformed. It is therefore necessary to resharpen the bit, in order to have. it properly function, and without marring the head of the screw uponwhich it is used.

Applicant has devised a sharpening device which will grind the opposite sides of the bit evenly with relation to the axis of thescrewdriver, which is very important, particularly when l dealing with minute screws such as are used in a 501 jewelers trade; and applicant has further provided a device wherein the end of the screwdriver, after being sharpened, is round, square or, in other words, faced, so that it will properly seat in the slot of the screw. 55 In the accompanying drawings wherein for Other objects andadvantages will be apparent the purposeof illustration is shown a preferred embodiment ofmy invention, it will be noted that my device consists of a base 5, which is preferably rectangular in shape and forms a convenient means for mounting my device in a vice commonly used on jewelers benches. Upon this base is secured a rectangular housing 6, the front of which is open, as shown inFig. 2.. Slidably mounted in the housing 6 is a carrier 1, which carrier is pressed upwardly by a spring 3, inter 10 posed between the bottom ofthe housing 6 and the bottom of the carrier 1. Counteracting the tension of a spring 8 is a threaded member 9, having a knurled head ll, through the medium of which the screw member 9 may be adjustably 15 rotated tomove thecarrier l against the tension of the spring 8. l

Mounted in the carrier 1 is a shaft [2, upon whichis secureda driving gear l3 and a grinding wheel M. A shaft I6 is journalled in the housing 2 6 and passes through slots formed-inthe carrier 'l, and has mounted thereon a gear H, which meshes with the gear l3. The shaft alsocarries .agrinding wheel Hi. This shaft'may be driven in any convenient manner, but I have here shown 5 a crank handle [9 rotating the same. l

Secured to the front of the housing 6 is an extension 2|, which serves to position the bifurcated end of a tool carrier 22. The carrier 22 comprises a fiat base portion 220. having one end 30 remov-ably pivoted tothe housing at 2|. From each side edge of the flat base portion extends a side portion 22b, these side portions being parallel. The upper end of this tool carrier extends through a slot 23, formed in the top of the 5 housing fi.

Mounted in the carrier is a tool holder 24, in which is formed bores 26, 2?, 28 and 29. This tool holder is mounted upon stub shafts 3|, which ride in inclined slots 32, formed on the opposite 0 sides of the toolcarrier. The tool holder is in theform of a block having parallel side faces and fits snugly between the sides 22b of the carrier. Moreover, the block forming the tool holder has a square periphery and the stubshafts or pins 3| 45 are fixed in the block in the centers of its side faces so that the block may he slid outwardly and inwardly to and from the carrier base 22a. and when slid outwardly it maybe rotated. By this means aselected peripheral side of the block may be engaged against the base 22a. The base 22a is provided with an opening 220 and when a selected side of thetool holder engages the base a respective bore will align with the hole or opening 220. The several bores are of different diameters to accommodate different diameters I which serves to prevent grooving of the stone.

of screwdrivers and by the means just described, a selected bore may be aligned with the opening Zlic for the reception of the screwdriver to be presented. This arrangement permits the tool holder to be moved away from the grinding wheels, so as to be rotated, as indicated in dotted lines in Fig. 1, the purpose of which will be later seen.

It is also to be noted here that the edge faces of the tool holder are each provided with an inclined groove 33, the purpose ofwhich will be later seen.

The tool carrier is provided with a slot 1%, as best illustrated in Figs. 5 and 6, the slot being of sufiicient horizontal width to accommodate the widest screwdriver which may be sharpened in the device. The slot is formed by striking the metal so as to form curved lips 35, separated from each other a predetermined distance, the purpose of which will be later seen.

The operation of my device is as follows: 7

Assuming that the parts have been assembled, as shown in Figs. 1 and 2, and it is desired to sharpen a screwdriver, the same is placed through one of the bores, as, for instance, the bore 26,

and assuming the same is the proper size to accommodate the particular screwdriver to be sharpened. When the screwdriver is in place, as shown in Fig. 5, the point thereof will come to rest between the grinding wheels it and it.

The operator now presses thethurnb against the thumb piece A of the screwdriver, and the first finger is placed at approximately the point B on top of the tool holder. The crank L9 is now rotated in a clockwise direction, while the first finger moves the carrier back and forth, as indicated by the double ended arrow of Fig. 2, thus moving the screwdriver bit back and forth across the stone during the sharpening operation,

After the bit has been ground a sufiicient amount, the tool as a whole is removed from. the holder and laid in the groove 33 on the'top of 1' the holder, as illustrated in Fig. 6, with the point engagement with the wheel [8. By again rotating the crank IS the end of the bit will be ground away until the distance between the curved lips 36 prevent further movement of the bit toward the grinding wheel.

It is, of course, understood that the tool carrier is moved back and forth in the same manner to causethe bit to travel across the full face of the grinding wheel, as previously described for the sharpening operation.

It will thus be seen that I have produced a one side, a pair of adjacent grinding wheels mounted in said housing with their axes parallel toeaoh other and equidistant from the open side thereof a tool carrier including a flat base portion having an opening therein and a pair of parallel side plates, said side plates having oppositely disposed slots extending outwardly from the centers of the plates, a tool holder having parallel sides and a square periphery and slidably and rotatably fitted between said side plates to .have its peripheral sides selectively engageable against the carrier base portion, said holder being provided with tool positioning means for each side of the holder periphery alining with the base opening upon a selected side of the tool holder engaging said base portion, and pivot pins fixed in said tool holder at the center of its'sides and engaging in said slots.

2. The sharpening device of claim 1 wherein the carrier has one end pivoted to the housing to permit swinging of the tool holder transversely of the grinding Wheels.

CLARENCE RAYMOND ELLIS.

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