Mat cutter guide
FIELD OF INVENTION 
     Cutting, with work mobilizer, guide for traveling cutter in class 83, subclass 455. 
     OBJECTS 
     The primary object of this invention is to provide a guide for cutting mats for pictures, wherein a traveling cutter is moved along a straight edge of a cutter guide which is spaced inwardly a predetermined distance from an outer edge of the mat. In this configuration, wherein the four edges of a rectangular mat are successively disposed beneath the cutter guide, it is intended to provide not only for adjustment of the cutter guide towards and away from an edge on a supporting board for predetermined increments of distance, but also automatically and simultaneously adjusting an end stop on the cutter guide similar distances from an adjacent edge on the mat. In other words, if the cutter guide bar is spaced &#34;x&#34; inches from the edge on the supporting board (against which one of the mat edges is engaged), the end stop on the cutter guide bar will automatically be set at a similar or proportional distance inwardly from an adjacent edge of the mat. 
     This invention automatically solves a most difficult problem previously inherent in the use of a mat cutter, namely, where to stop the mat cutter so that the cutting edge of the blade will stop precisely at an inner corner of the mat. 
     In furtherance of the foregoing object, it is also intended to provide for adjustment of the cutter end stop along the length of the cutter guide bar so as to compensate for mat cutters of different makes wherein the distance from the blade edge to the nose of the cutter varies from make to make. 
    
    
     These and other objects will be apparent from the following specification and drawing, in which: 
     FIG. 1 is a plan view of the mat cutter guide positioned for one marginal dimension; 
     FIG. 2 is a view similar to FIG. 1, but showing the mat cutter guide positioned for a longer marginal dimension; and 
     FIG. 3 is a fragmentary plan view showing details of the plates, holes and pins. 
    
    
     Referring now to the drawing, the guide 1 consists of a board 2, preferably stiff, having a strip 4 along one edge which provides an upstanding straight edge 6. Another strip 8 adjacent the end of strip 4 provides an upstanding edge 10. The guide is for cutting between borders of a rectangular mat 12 having, in this example, outer edges 14, 16, 18 and 20. In the illustrated device, mat edge 14 is engaged against the upstanding edge 6 of strip 4 and mat edge 16 engaged against the upstanding edge 10 of strip 8. 
     A bar 22 moveably disposed over mat 12 provides a straight edge 24 which, as will be apparent hereinafter, is maintained in parallelism with the upstanding edge 6 of strip 4. At the left hand end of bar 22 is an end stop 26 which is adjustable lengthwise of bar 22 by means of screws 28 engaging in slots 30. The lengthwise adjustability of cutter stop 26 is to accommodate the guide to cutters of various makes which have their blade edges disposed at different distances from the cutter nose. 
     The straight edge 24 of bar 22 is maintained parallel to the straight edge 6 on strip 4 by two similar plates 32 and 34 each having a diagonal row of holes 36 therethrough. The lines of holes 36 are at an angle of 45° with straight edge 24 on bar 22 and in the example given, the holes are spaced 0.177 inches from one another. Holes 36 are engageable over pins 38 on strip 4; and with the row of holes forming a 45° interior angle to straight edge 24 on bar 22, the adjustment from one hole to the next provides an incremental adjustment of the spacing between straight edge 24 on bar 22 and straight edge 6 on strip 4 of 0.125 inches per hole. Since the rows of holes 36 are at 45° to straight edge 24 on bar 22 it will be seen that when an adjustment is made from one hole to another, bar 22 is likewise moved 0.125 inches, thereby moving cutter stop 26 the same distance to the right or left, depending upon whether the pin selection is made to move bar upwardly or downwardly with respect to straight edge 6 on strip 4. 
     In operation, a mat 12 is placed with its adjacent edges against straight edge 6 on strip 4 and edge 10 on strip 8 and a measurement is made to start the cut at a point p on the mat, which is spaced at a certain distance from the outer edge of the mat. This is the only measurement required for cutting all of the four inner edges of the mat. The first cut is made at a predetermined distance from the edge 14 of the mat, and when the first cut has been completed the mat is turned so as to present the mat edge 16 against edge 6, and the second cut is made; likewise the third and fourth cuts are made by turning the mat 90° for each cut. 
     If desired, the border adjacent mat edge 16, for example, may be made wider than the border adjacent the opposite mat edge 20 by taping a temporary cutter end stop on the regular end stops 26.