Abstract:
A film cutter which includes a supporting frame structure with a translucent supply side platform mounted thereon and adapted to be illuminated by an underlying light source and including a film cutter mounted on the frame structure.

Description:
BACKGROUND OF THE INVENTION 
     In the past, transparency film cutters have been relatively difficult to operate and close tolerance trimming and cutting have been relatively difficult and time consuming. None of the cutters presently in use permit viewing of the transparency during the positioning and cutting operation. 
     SUMMARY OF THE INVENTION 
     The present invention provides an illuminated supporting platform which permits quick and easy viewing and positioning of the transparent filmstrip to be trimmed. A cutter unit is slidably mounted on a rigid guide bar which is permanently aligned with the cutting edge of a translucent viewing and positioning platform to facilitate accurate positioning of the transparency strip for trimming thereof. It is particularly important that the precise selected cut line of the transparency can be quickly and easily positioned at the cutting edge of the platform so that the operator may view the transparent strip and the area to be trimmed. The present construction includes a translucent illuminated &#34;supply&#34; side platform which overlaps a portion of the &#34;off-cut&#34; side platform located below the cutting edge portion of the supply side platform. This provides reinforcing strength and rigidity to the overlying cutting edge of the supply side platform and also prevents the trimmed material from falling into the area below the two platforms. In addition, the cutting edge formed by the supply side platform is aligned with the path of the cutter blade and is provided with a relief edge portion in the lower portion of the cutter path to minimize damage to the cutter blade and also to the cutting edge of the platform. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a film cutter embodying this invention; 
     FIG. 2 is a fragmentary vertical sectional view taken substantially along the line 2--2 of FIG. 1; 
     FIG. 3 is a vertical sectional view similar to FIG. 2, but showing an alternative cutting edge construction; 
     FIG. 4 is a similar vertical sectional view to FIG. 3 but showing another modified cutting edge construction; and 
     FIG. 5 is a fragmentary perspective view of a portion of a cutter showing the modified cutting edge illustrated in FIG. 4. 
     FIG. 6 is a perspective view showing the frame removably mounted to the base. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As best shown in FIG. 1, a supporting frame 10 is provided in which a translucent supply side platform 12 is rigidly mounted. A light source (not shown in FIG. 1) is provided under the platform 12. The platform 12 may be square in shape and removably mounted within the frame 10 to permit all four sides or edges thereof to be used as a cutting edge 12a. Also since only the &#34;top&#34; edge forms the cutting edge, the platform may be inverted to provide a total of eight cutting edges. 
     A second platform 14 is rigidly mounted within the frame 10 with one edge portion thereof underlying the marginal edge portion of supply side platform 12 adjacent to the cutting edge 12a thereof to provide reinforcement for the overlapping marginal edge portion of platform 12. The reinforcing marginal edge portion of platform 14 which underlies the marginal edge portion of platform 12 is designated by the reference character 14a. 
     A pair of cutter bar supporting brackets 16 are rigidly mounted to the edge portions of the frame 10 and positively anchor a cutter transfer bar 18 in overlying spaced relation above the cutting edge 12a. A cutter slide 20 is slidably mounted on the bar 18 for back and forth travel thereon and a cutter wheel 22 is rotatably mounted on a spindle 23 rigidly supported on the cutter slide 20. In order to minimize damage to the cutter edge 12a of the platform 12, a relief recess 12b is formed in the cutter edge 12a of said platform to minimize frictional engagement between the peripheral cutting edge 22a of the cutter 22. 
     An alternative supply side platform 25 is illustrated in FIG. 3 wherein a layer of relatively soft material 26 is laminated into the cutter platform 25 which has a cutting edge 25a. The relatively soft laminated layer 26 serves the same general function as the relief recess 12b by protecting the peripheral cutting edge 22a of the cutter 22. An off-cut platform 14 is provided which is similar to the off-cut platform 14 shown in FIG. 2. 
     In the form shown of the invention shown in FIG. 4, a supply side platform 30 is provided wherein a hardened steel alloy strip 31 is fused or permanently bonded to the edge of the platform 12 adjacent to the cutting path of the cutter wheel 22. The strip 31 forms a cutting edge 31a for the transparency film being cut. An off-cut platform 14 is also provided as in the other forms of the invention. 
     The platform 25 may be provided with a guide or marker grid to assist an operator to position a film transparency quickly and accurately thereon. 
     FIG. 6 shows a separate illuminating base section 30 on which the frame 10 can be removably mounted. The frame 10 has a plurality of openings 10a which register with upstanding pins 30a provided in the upper edge of the base section 30 to hold the two sections together.