US2251849A

US2251849A - Tool sharpener

Info

Publication number: US2251849A
Application number: US333040A
Authority: US
Inventors: Arthur B Mawle
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-05-02
Filing date: 1940-05-02
Publication date: 1941-08-05
Anticipated expiration: 1958-08-05

Description

1941- A. a. MAWLE 2,251,849

TOOL SHARPENER Filed May 2, 1940 j I H IHI JJ Patented Aug. 5, 1941 UNITED STTES 4. Claims.

This invention relates to a tool sharpening device.

More particularly, the invention relates to a device for sharpening tools and having special adaptation to the sharpening of the blades of shears, scissors and the like.

As is generally known, the cooperating edges of the opposed blades of shears and scissors are slightly bevelled to provide maximum cutting efficiency and in the re-sharpening of such blades it is essential that the original bevels be maintained if the cutting efiiciency is to be retained.

The sharpening of the blades of shears and scissors has heretofore been done by various means ranging from a file to more or less efiicient devices for supporting or guiding the blades during the sharpening operation.

While the blades may be properly sharpened by the use of a file, it is very difficult to secure a uniform bevel from one end to the other of the blades. This is likewise true if a rotary stone or the like, be used, wherein the blades are manually guided and which requires much care and skill to secure a uniform bevel.

Furthermore, devices have heretofore been proposed which include an abrading surface and restricted guide means for a scissors blade whereby the blade may be manually reciprocated thereby moving the edge lengthwise over the abrading surface for the sharpening thereof.

A device of this general character is disclosed in the British Patent No. 172,450, December 15, 1921. Wherein the guide is relatively short and as the slot between the walls forming such guide is of necessity substantially wide to accommodate the wider backs of the blades, it would require considerable care and skill to so reciprocate the blade as to secure a uniform bevel on the cutting edge thereof. Furthermore, such device leaves the major portion of the blade exposed as a result of which ones fingers may be cut during the sharpening operation.

A primary object of this invention is the provision of a sharpening device which substantially overcomes the above noted objections, and which is endowed with the maximum requirements of devices of this character.

A further object of the invention is the provision of a device for sharpening the blades of shears, scissors and the like embodying means for fully concealing the edges of the blades and maintaning same in fixed position throughout the lengths thereof during the sharpening operation.

A still further object of the invention is the provision of a device which is highly simple in construction and which is capable of being readily dis-assembled for repair or replacement of parts.

For a more complete understanding of the objects and nature of the invention, reference will be had to the following detailed description, taken in connection with the accompanying drawing, wherein- Figure 1 is a top plan view of the device, constructed in accordance with a preferred embodiment of the invention.

Figure 2 is a longitudinal vertical section in a plane substantially as represented by the line 2-2 in Figure 1.

Figure 3 is a left hand end elevation of the device.

Figure 4 is a transverse section in a plane represented by line 44 in Figure 2.

Figure 5 is a right hand end elevation of the device.

Figure 6 is a side elevational view, on .a reduced scale, showing a pair of shears or scissors in sharpening position in the device.

Referring now in detail to the drawing by the use of reference characters, and wherein like characters designate like parts in the different views, D designates the device in its entirety and which in its elemental construction comprises a casing ID which is preferably cylindrical in form as illustrated, but which may well be of other forms so far as the essence of the invention is concerned.

The casing 50 may be of wood, metal, or a composition material and may be of any preferred length and diameter. The length however, should be at least equal to the length of the blades of the larger shears or scissors for reasons which will later appear.

The casing It! is provided with a bore ll in which is rotatably mounted a cylinder or roller [2, the bore l I being of slightly greater diameter than that of the roller l2 to provide for free rotation of the latter.

The roller [2 may be mounted and actuated in various ways but preferably, and as shown, the roller is supported on a spindle i3 which is preferably force fitted in an axial aperture in the roller for joint rotation of the roller and spindle.

The spindle l3 at one end thereof (the left in Figures 1 and 2) projects freely through an. aperture in an end plate [4. The spindle adjacent its opposite end projects freely through an aperture in another end plate l5, the spindle adjacent the exterior of the plate [5 being bent at right angles and radially extended to provide a roller operating crank I 6 having a suitable handle l1 freely rotatable thereon.

Th end plates l4 and I are preferably secured to the casing ID as by screws I8 for ready removal thereof whereupon the roller l2 together with the spindle l3 can readily be removed from within the casing bore H.

The casing I0 is provided with a longitudinal slot 20, in a position to be bisected by a plane radial to the casing Ill and the slot extends entirely through the wall of the casing and throughout the length thereof. The end plate I4 is slotted at 2| in conformity with the slot 20 which latter is closed at its opposite end by the end plate l5.

The roller l2 may be of wood or other desire material and the cylindrical surface thereof is suitably coated to provide an efficient blade edge sharpening surface. I

This abrading coating indicated at C is preferably provided by rendering the surface of the roller adhesive as by coating same with glue and thereafter rolling it in an abrasive material such as emery powder whereby a highly efficient grinding surface 'is provided.

The slot 20 is relatively wide and in the sharpening operation the blade B of a shears or scissors S is placed longitudinally therein as indicated in Figure 6 with the bevelled edge in contact with the abrading roller I2, and due to the width of the slot the blade is canted as illustrated by dotted lines in Figure 4 and in this position the blade is firmly held by a hand of the operator whereby the bevel will uniformly} contact the roller l2 throughout the length of the blade. The slot 21 in the plate l4 admits the blade and the other end plate prevents engagement of the hand with the end of a long blade which may otherwise occur when rotating the roller through the crank l6.

With the blade in the position shown in Figure 6 which may be firmly held together with the casing I!) in the left hand, and handle I! is grasped by fingers of the right hand and the roller I2 rotated at relatively high speed where- 'upon the edge of the blade B is rapidly and efficiently sharpened with a uniform bevel. The other blade of the shears S may then be inserted in the slot and be likewise sharpened.

When the abrading coating on the roller l2 becomes ineffective the plate l5 may be quickly removed, the roller I2 withdrawn, and a new abrasive coating applied thereto.

It should readily be appreciated from the foregoing disclosure that the invention provides a 'novel sharpener whereby the blades of shears,

scissors and the like may be quickly and accurately sharpened without in any way subjecting the operator to danger of being cut by an exposed edge being sharpened.

While I have disclosed but a single specific embodiment of my invention, such is to be considered as illustrative only, and not restrictive, the scope of the invention being defined in the sub-joined claims.

What I claim, and desire to secure by United States Letters Patent is:

1. A device for sharpening the blades of shears, scissors, and the like, comprising an elongated tubular casing, a centrally apertured plate detachably secured to each end of the casing, a spindle extending axially through the casing and rotatably supported in said apertures, a manipulating crank on one end of the spindle, an abrading roller secured to the spindle and a slot extending through the wall of the casing and throughout the length thereof, the plate at the end of the casing adjacent the crank closing the adjacent end of the slot, and the other plate having a slot alined with the slot in the casing for receiving a shears blade its full length within the casing slot and with its edge in bearing contact with the roller.

2. The structure defined in claim 1 wherein the slot in the casing is radially disposed in transverse section of the casing and is of substantial width for positioning the blade nonradial to-the casing for proper and uniform bevelon the edge being sharpened.

3. A blade sharpening device comprising an elongated casing having a bore extending longitudinally therethrough, an abrading roller rotatable in the bore, a longitudinal slot extending through the wall of the casing and opening through both ends thereof, and plates secured to the opposite ends of the casing, one of the plates having a slot conforming to the adjacent end of the slot in the casing to admit a blade, with its edge in contact with the abrading roller, and the other plate closing the other end of the casing slot, said roller being supported by an axial spindle, said plates being centrally apertured for freely receiving the spindle, and a crank on one end of the spindle.

4. A blade sharpening device comprising an elongated casing having arbore extending longitudinally therethrough, an abrading roller r0- tatabl-e in the bore, a longitudinal slot extending through the Wall of the casing and opening through both ends thereof, and plates secured to the opposite ends of the casing, one of the plates having a slot conforming to the adjacent end'of the slot in the casing to admit a blade, with its edge in contact with the abrading roller, and the-other plate closing the other end of the casing slot, said plate'being removably secured to the casing for expeditious removal and re- ARTHUR B. MAWLE.