US3172587A - Sandpaper tearing guide - Google Patents

Description

March 9, 1965 J. w. FREEMAN 3, 7

SANDPAPER TEARING cums Filed Oct. 5, 1962 v 2 5 INVENTOR.

United States Patent F 3,172,587 SANTEYAPER TEAG GUIDE James W. Freeman, 2745 Lindale Ava, Qedar Rapids, Iowa Filed Get. 3, 1962, Ser. No. 228,975 1 Claim. (Cl. 225-89) This invention relates generally to guide apparatus and more specifically to guides for tearing operations.

One object of the present invention is to provide a tearing guide for sandpaper which will accurately tear a standard sheet of sandpaper into either /4 size for use on sanding blocks or /3 size for use on orbital sanders. It is generally well known to those skilled in the art that sandpaper is relatively less expensive it purchased in standard sized sheets rather than sandpaper which is already prepared in sizes for specific use on orbital sanders or for sanding blocks.

Accordingl it is another object of the present invention to provide a sandpaper tearing guide which will be more economical and eliminate the need of purchasing the relatively more expensive sizes of sandpaper.

Still another object of the present invention is to provide a sandpaper tearing guide which can be quickly adjusted in order to change from one tearing size to another.

Other objects of the invention are to provide a sandpaper tearing guide bearing the above objects in mind which is of simple construction, has a minimum number of parts, is inexpensive to manufacture and eiiicient in operation.

For other objects and for a better understanding of the invention reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which:

FIGURE 1 is a side elevational view of the present invention shown partly in cross section;

FE JURE 2 is a top plan view of the base element shown removed in its entirety from the assembly illustrated in FIGURE 1;

FIGURE 3 is a cross sectional view taken on the lines 3-3 of FIGURE 2 and looking into the direction of the rows thereof; and

IGURE 4 is a top plan view of the cutter block shown removed from the base element.

Referring now to the drawing in detail, the numeral it represents a sandpaper tearing guide according to the present invention wherein there is a base element 11 and a cutter block 12. The base element is made from sheet steel which is bent up to form the structure as shown in FIGURE 2 of the drawing. It comprises a bottom wall 13 of generally rectangular configuration having a front edge 14, adjacent its rear edge there is an upstanding rear Wall 15 and adjacent each opposite side edge of the bottom Wall there is an upstanding end wall 16. The end walls and the rear wall are all of relatively equal height. The forward edge of each or" the end walls is gently rounded as shown at 17 in order to eliminate any dangerous corner upon which a workman might injure hi i-- self. On the upper side 18 of the bottom wall there is a leaf spring 19 of generally longitudinal character and which is attached at one of its ends to the bottom wall 3,172,587 Patented Mar. 9, 1965 by means of a rivet 20. The leaf spring is made preferably from brass material and is of generally upwardly convex character along its length as indicated by the bold portion 21 in FIGURE 3 of the drawing. The opposite longitudinal end of the leaf spring is free and extends toward the forward portion of the base element. Each of the end walls is provided having a horizontally extending slot 22 as shown in FIGURE 1 which is of a known length and which is in a known position relative to its distance from the rear wall. The cutter block is made preferably from a block of wood material and is of generally rectangular prismatic configuration having a bottom wall 23, a top wall 24 parallel to the bottom wall, a vertical front wall 25, parallel vertical end walls 26 and an arcuate rear wall 27. A handle 28 is attached to the upper wall of the cutter block by means of screws 29 at each of its ends. A blade element St) is attached to the underside 23 of the cutter block in a position so that a serrated edge 31 of the blade element projects slightly beyond the front wall 25 of the cutter block. The blade element is made of steel material in order to remain sharp a relatively long time. A pin 32 is attached to the cutter block in each opposite end Wall, the pin extending outwardly from the end wall for a sufficient distance so that when the cutter block is placed upon the bottom wall of the base element between the opposite end walls 16 thereof the pins will extend and project through each of the slots 22 in the opposite end walls.

In operative use, a standard sheet of sandpaper 32' is inserted between the upper side of the bottom wall of the baseelement and the cutter block, the sandpaper passing over the leaf spring until the rear edge 33 of the sandpaper is adjacent the rear wall 15 of the base element. The cutter block is then moved rearwardly until it is in the position as illustrated in FIGURE 1 wherein the pin is adjacent the rear end of the slot 22. In this position the tearing guide is adjusted for tearing the sandpaper for use on sanding blocks. The forward portion of the sandpaper is now lifted and torn against the serrated edge, the resultant torn sandpaper is torn producing a A1 size which is readily adaptable for sanding blocks. When it is desired to tear standard size sheets of sandpaper into thirds for use on orbital sanders the cutter block is moved in the opposite direction until the pins 32 are adjacent the opposite ends of the slots. The paper is then torn against the serrated edge in a similar manner.

Thus there has been produced a sandpaper tearing guide which Will accurately tear a standard sheet of sandpaper into either A1 size for sanding blocks or /3 size for orbital sanders.

While various changes may be made in the detail construction it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claim.

What I claim as new and desire to protect by Letters Patent of the United States is:

A sandpaper tearing guide comprising a base element having a fiat bottom and integral vertically extending side and rear walls, a leaf spring secured on the upper surface of said flat bottom adjacent one side wall, a cutter block having opposite side edges and a tearing edge along its front edge and being adjustably and slidably supported on said base element for forward and backward movement, means for adjusting said cutter block with respect to said base element for tearing a sheet of sandpaper into various sizes, said adjusting means being formed by longitudinally extending slots in the vertically extending side walls of said base element and cooperating pins in the opposite side edges of said cutter block extending through and slidable in said slots in the side walls of said base element, and a handle on said cutter block.

UNITED STATES PATENTS Carter Oct. 8, Smith Mar. 10, Wilson Nov. 11, Kinkead et a1 Get. 15, Kramer Mar. 13, Euth Mar. 28, Johnson June 29, Schultz Jan. 10,

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