US2180230A - Sharpening device - Google Patents

Description

NOV! 1939. s. T. FREETH SHARPENING DEVICE I Filed Jan. 7, 1938 r z z? IIHHHIITTI? d 1 III IlllllIIHIIIIHIHH IILI I amlllllflllHHHIHIIHIIIIQIEHHHI II HI Patented Nov. 14, 1939 omrieo STAT 1 Claim.

This invention relates to sharpening devices and particularly to a general-utility device of this character particularly adapted for sharpening scissors, knives, skates, lawn mower knives and edge-tools.

One object of the invention is to provide a simple and inexpensive device of this character by which a file or other abrasive body may 'be supported at any desired or necessary angle against theedge face of an implement or tool to be sharpened, the device including a support for the article to be sharpened, :which may be adjusted so that the angle of the-file shall secure the proper bevelon the edge of the blade.

Another object is to provide an adjustable support :for the article to be sharpened and a file supporting bar and a guide slidably engaging the support, means'being provided whereby the article may be supported with its edge at the proper angle to secure the proper cutting bevel.

A further object "is to provide a device of this character in which the file support and guide without the stand may be used for sharpening lawn mower blades either the rotary blades or the fixed blade.

My invention is illustrated in the accompanying drawing wherein:

Fig. 1 is a side elevation of my sharpening device, the cross-bars on the stand and the implement being sharpened being in section.

Fig. 2 is a longitudinal elevation of the file supporting'bar on the file, the figure showing in sectionthe cross-bar of a mowing machine, the sliding guide being also shown in section.

Fig. 3 is an underside plan view of the adjustable guide.

Fig.4 is a perspective view of the stand.

Referring to the drawing, it will be seen that the stand is formed preferably of a single length of heavy rigid wire or rod to provide an upper cross-bar I and a lower cross bar ll. Each cross bar has legs l2 connected by the longitudinal portions l3. The lower cross-bar II is preferably formed at its middle with an enlarged cylindrical portion I l. While I have shown a stand which is particularly simple and which is cheap to construct, yet I do not wish to be limited to the exact form of this stand provided it embodies the lower and upper parallel cross-bars.

Mounted on the lower cross-bar is an article holder in the form of a vise having the fixed jaw l5, the movable jaw IS, the screw Ill for shifting the movable jaw, the depending arm I8 and the vertically disposed clamping screw H! which at its inner end carries a head 20 whose Lthick tool blade.

cross-par M .until the beveled edge .of the :tool

face is concave to partly embrace the cross bar M. of course, by adjusting the screw, the device may be clamped upon the cross-bar 14 at any desired angle.

The file holder and guide: comprise a'straightt; flat 'bar :21 formed .ati-one end to :provide a :hook

22 and adapted to more or less closely embrace the cross-bar It. This hook portion is trans versely slotted at 23 adjacent the baseof 1311611001;

portion to permit the passage of theshank portion 4:11) or body of a file-Aer other abradi-ng implement.

This :bar 2:! .is long enough :to extend over the .loladeof the article to be sharpenedwhichzblade i supported between the jaws of the =vise with the :file A bearing against the blade. p

.slidingly mounted on the-bar Zl a guide #214 This is formed of an initially flat plate of sheet metal bent downward .at its ends .at .25, and then inwardwat 255. The downwardly lbent ends 74f; are slotted at :2 and through these slots the 'bar 2*! and the file .A extend. .A :set ;.screw :28 passes through the :top of guide 24 and bears against the upper face of the bar clamping. :the

The use of this device as a means for sharpening between the jaws of the vise and :the'vise is-then turned :in one direction or the :other around the is brought into such position that the underface of the file will bear flat against this beveled edge when the file is in use. The clamp screw is then turned to clamp the vise in this adjusted position. The hook of the file supporting bar is then engaged with the upper cross-bar of the stand with the underface of the file resting fiat against the edge of the tool being sharpened and with the edge ofthis tool disposed in the slot between the lugs 30. When the parts have been properly adjusted, the file is shifted back and forth along the edge of the tool 13 as, for instance, along the edge of one blade of a pair of scissors, thesupporting bar being guided by the hook engaging the upper crossbar of the stand and by the depending lugs small tools will be obvious. The tool .is placed 30 which engage on each side of the blade being sharpened.

It is to be understood that while I have illustrated a complete file with. the body portion of the file disposed beneath the whole length of the supporting bar, yet only a small portion of a file need be used as, for instance, a fragment of a file provided this is clamped within the sliding guide 24 and has its underface bearing against the beveled edge face of the article being sharpened. With this construction, the file may be shifted from time to time so as to bring undulled or fresh portions of the file againstthe edge of the article being sharpened. This is particularly capable of being accomplished provided the file has no handle.

While I have referred to a file proper as th abrading means, it is to be understood that any other body of abrading material might be used disposed against the underface of the supporting bar and supported within the guide 24 by the pressure of the set screw on the supporting bar. Thus files or abrading implements or bodies of various degrees of fineness may be readily applied and used with this sharpening device and I do not wish to be limited to the use of a file proper, and I wish it understood that by the term file as used in the claim, I refer to any body having an abrasive face.

This device as previously stated may be used also for sharpening lawn mower blades. In this case, of course, the stand is not used. There is nonecessity of taking a lawn mower apart in order to use the sharpening device. For the purpose of using the sharpening device on the lawn mower, the rear, end set screw on each side of the main bar of the lawn mower is loosened to allow the rotary cutter to revolve freely. The hook of the supporting bar 2| is hooked over the fixed cross-bar 32 of the mowing machine and the guide 24 is adjusted over one of the rotary blades B so that the file or other abrading implement supported upon the underfaces of the bar 2| will give the proper bevel to the edge of the blade. The guide is then clamped in its adjusted position by the set screw 21 and then the unit is pushed back and forth with a light pressure a few times over the rotary cutter from one end to the other until the original bevel face is bright from front to back. Each rotary blade is similarly treated until all the blades have been sharpened. The unit is then removed and the guide 24 pushed to about 2" from the lower end of the bar 2| and clamped in place. The fiat of the file is then broughtdown on the stationary cutter of the :mowing machine to its original bevel and with a few even strokes of the file from end to end, this stationary cutter bar is sharpened. In actual practice this method of sharpening has been found not to take the temper out of the steel cutters and make them soft and useless.

It will be seen that this device may be cheaply constructed and sold, that it may be used with either a large or small file or with even broken parts of files or with other abrasive bodies. The downwardly extending lugs 30 constitute relatively deep guides on each side of the blade which will prevent the device from running off of the blade which is being sharpened. The device is easy of adjustment and by reason of its adjustability it can be adjusted to suit any predetermined bevel on the edge of the blade.

By reason of the relatively wide slot 29 between the lugs 30, the adjustable guide will permit the sharpening of a lawn mower blade to the greatest possible extent as the lugs 30 are spaced apart sufliciently to permit even the bar supporting the blade and in which the blade is attached to enter between the lugs.

While I have illustrated certain details of construction and a certain arrangement of parts which I have found to work extremely well in practice, yet I do not wish to be limited to these details or the exact arrangement shown as these details might be modified in many ways without departing from the spirit of the invention as defined in the appended claim.

What is claimed is:

A sharpener of the character described, comprising a stand having base portions and two parallel horizontal cross-bars secured to and supported by the base portions, said cross-bars being disposed one in a higher plane than the other, a work holding vise having opposed clamping jaws and having a depending arm carrying an upwardly extending clamping screw, a sleeve encircling the lower one of the horizontal crossbars, said clamping screw having a head adapted to partially embrace said sleeve whereby the vise (40 may be rotatably supported upon the lower crossbar to thus adjust a piece of work held between the jaws to a desired angle, a supporting bar having a hook at one end to loosely engage the upper cross-bar and a guide slidably adjustable 2'45 along the supporting bar and having opposed slots through which the supporting bar may extend together with a file disposed longitudinally of the underface of the supporting bar, the hooked end of the supporting bar having a slot through which may extend one end of the said file, and a set screw passing through the top of the guide and adapted to bear against the supporting bar and clamp the supporting bar and file together, the slide having a transverse open' ing on its underface adapted to receive the work held between said jaws, and having downwardly extending guide lugs disposed upon opposite sides of the work SAMUEL T. FREETH. no

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