CA1056297A - Graphic arts t-bar razor - Google Patents

Abstract

A B S T R A C T
In a tool for cutting film or cardboard, it is known that a guillotine or industrial razor blade has been established as the method of cutting, and that mechanisms without power are marketed for manual steel rule cutting on top of the artwork.
In this invention, the severing action of a 2000 r.p.m. motor driven circular razor, and the perfectly straight guidance of a fluorocarbon bearing carriage across a rigid transverse T-bar set at a maintained height above a table platform, makes heavy cuts without twisting or skewing and without clamping. The design incorporates a slide that lifts and lowers to manipulate the inside bevelling of matboard. Interchangeable with the razor arbor is a small diameter fine tooth saw arbor with an attachment for smooth cutting on thin paper. The motor switch is a press on, hold, and release stop action entirely favourable to the concept of non-clamping.

Description

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; S P E C I F I C A T I /~ N

This invention relates to a compact electric circular razor or saw for severing bond or vellum drawings, heavier matboard or cardboard, photographic sheet film, sheet plastic or plywood within a range of ~003" to .250", and can be tilted to any predetermined angle including 45 degrees.
It is common in devices for severing in the photographic display and picture framing businesses, to manually cut materials with an industrial razor blade set in a slide block passing it along a steel straightedge that lays on top of the artwork. This 10 hand method is slowly effective on lighter cuts, but on materials over .040" needing more than one pressure cut to slit through to the severing point, the method is inadequate. Mechanically improved models that use razor blades but remain without a power source, are also a problem.
I have found that present limitations can be overcome and appllcations extended by using a small commercially available 90 degree, geared motor producins 2000 r.p.m. to drive a circular razor 2.7" diameter for sheet matboard up to .060"
thick; cardboard, plastic or wood from .040" to .25" thick, is ; 20 severed with a slitting saw, and for paper of .003" thickness, an attachment is provided. The power drive is mounted on a carriage parallel to the flat of a hardened aluminum T-bar, sliding freely ;- on fluorocarbon bearings and moving with an optional 24" to 60"
length of traverse, so that either the circular razor or severance saw, when lowered to the pivot point at the table, moves in a straight line without twist or skewing and without clamping.
In drawings which illustrate embodiments of the invention:
Figure 1 is a ~ scale right side view of the T-bars, motor and stops detailed in an inset.
Figure 2 is a ~ scale plan view of the table and endplate indexes.

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05f~z97 Figure 3 is a ~ scale front end view of the motor slide and guarded circular razor-cutter.
Figure 4 is a ~ scale front view of the endplate showing the 45 degree tilt and razor-cutter change positions.
Figure 5 is a full scale plan view of the carriage detail.
Figure 6 is a full scale end view of the carriage slide - buttons.
The machine comprises features detailed 0 to 70 in 6 figures.
i 10 Figure 1 shows two aluminum T-bars; 0 which is .002" case hardened and 1 raw material, both optional in length from 24 to ..
60 inches but always 12" longer than table 4, both tapped with a 5/16-18 thread in the centre of the web on both ends. Table T-bar 1 is base for a pressed wood board 4 to which is latexed a dark grey poly-vinyl-chloride plastic top 5 and white plastic channel edge trim 6, fastened by wood screws coming up through the flat of the T-bar. The 0-1 T-bars are spaced apart by -endplates 2 front and 3 rear locXing into .he end holes of 'ho - bars using hex. head machine screws 7 and hardened heavy washers~; 20 10. Endplates 2-3 are matched pairs of ~" aluminum plate bored ~ to angle co-ordinates that set up a vertical 90, 45 or an ; optional angle. Pivoting wear is compensated for by oversize boring of the endplates and pressing in oil impregnated bronze bearings 13 and index bushings 14. There are two position locking angleplates 15 mounted on table T-bar 1 front and back using hex.screws 17, each supporting a 5/16-18 threaded stud 8, a stud nut 16, two light washers 11 and acorn nut 9 at the pivot ; point. On the left extremity of the locking angles 15 and fastened by three square socket screws 18, is a light ~" pin toggle index plunger 12 that fixes the point of the angle for the endplates 2-3 by entering into the index bushings 14.
Crossing T-bar 1 at the front only is a 24" straightedge 19 to aliqn the product squarely before the razor. It carries a side :

105tiZ97 ' stop 22 comprising a clamp locator angle 23, a flexible clamp bar 24 and two flathead square socket screws that ties the three components together. Rapid setting of the qauge into position is possible through the toggle clamp 12, and no damage in movement occurs because of the adjustable plastic hex. screw 20 and jam nut 21. Also outlined in this view is the right angle motor drive 29 and the razor-slitter 30. Figure 1 also shows as an inset view, the details of the distance setting clamps of the carriage T-bar, 25 is a 1" width of channel aluminum to caliper the bar, with two plastic runner blocks 27 to prevent pressure damage to the bar, and a steel pressure stud 28. The toggle pressure clamp comprising 12, 20, 21 is carried on a anglepiate 26.
~ igure 2 relates the plan view of the Figure 1 details adding 31 to 39 as new detail. 31 is a table filler angleplate which bridges the gap between the table top 5 and cross stEaightedge 19 shown held in place by square socket screws 32.
The motor is secured to the horseshoe of the carriage by a gear clamp 33, the four guard spacer screws 34 attach the razor cutter guard to the motor slide, and acorn nuts 35 removable for cutter change, hold the guard front plate. Attached to the carriage is a slide travel lever plate 36 held by two square .; .
socket screws 37. Identification 3~ is given in this figure to the razor holding arbor and 39 to the plastic wear strips between the endplates 2-3 and the locking angles 15.
Figure 3 relates to the end view of Figures 1 and 2 with the endplates removed for clarity and the identification of details 65 to 70 newly introduced. Two arbor spacers that strengthen the cutter thinness shown as 65 are in turn supported by two arbor filler flanges 66, all tightened together by a left threaded nut exposing a ~"x9/16" long arbor that is tightened into the motor drive chuck. The position of the inside guard plate 67 narrowest of the two to clear the carriage at the top ~ 1056Z~7 of the travel, and the outside guard plate 68 is shown. 69 i designates the toggle lever fastened on the toggle lever plate 36, Figure 2, and capped by a plastic ball 70 to compress the , springs and give control of the motor slide depth.
`` Figure 4 adds no new components but serves to demonstrate the possibilities of positioning from the pivot points.
Figure 5 adds full size details 50 to 61 specifying the parts that make up the vertical motor slide. 50 is the small set screws backing up the small fluorocarbon buttons 51 opposite the stationary slide buttons 52. The slide front bars of the carriage are 53, the rear 54. The motor horseshoe is a channel aluminum piece bored to a 1 1/8" arc to fit the motor contour and provide a centre fastening support to the motor slide 56.
The centre of the carriage is an anchor plate 57 of ~" thickness, `- counterbored with eight 5/16"x3/32" deep pockets to receive the stationary fluorocarbon buttons of both the slide and the traverse , carriage. The components 53, 54 and 57 together with 40-41 of Figure 6 are held in a fixed position by shoulder screws 58 and jam nuts 59. Identification is also made in this Figure of the `~ 20 two slide compression springs 60 and the motor centre, gear - clamp rivet 61.
~ Figure 6 adds full size detail 40-49 and 62-64 specifying '- the parts that make up the T-bar carriage. 40 is the upper bar cut out on top to receive the lever plate 36 Figure 2, bored and tapped to receive the large fluorocarbon buttons and set screws.
` 41 is the lower bar bored and tapped to receive the large ;- fluorocarbon buttons and set screws. 42 is the small fluorocarbon buttons that are bearings on the ~" edges o the T-bar backed ` up by set screws 45, while 43 is the large fluorocarbon buttons that are bearings on the flat ~f the T-bar backed up by set screws 44 locked in the tapped holes by adhesive. Other fluoro-carbon bearing components shown are 46 set into the pockets of : A
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the anchor plate 57, the larger of the slide buttons 47, backed up by set screws 48; also the hardened rest button 49 acting as the pusher pad for the travel lever 69. There are two ~"x~" .
angle plates 62 for fastening the chuck guard area of the motor with square socket screws 18 to the motor slide 56 and a view of the guard riser blocks 64 that are resting on the motor slide 56.
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Claims

The embodiment of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A manually moved hand motor for cutting off heavy card-board sheet material, consisting of an aluminum T-bar anodized and hardened to provide a bridge above a table platform, and a table support T-bar tapped in the web centre on both ends to accept the thread of the machine screws that lock two aluminum endplates bored to co-ordinates and bushing inserted at pivot and index locations, for toggle pin plungers fixing 45 and 90 degree angles, and to permit rapid dislocation of the T-bar and carriage containing the motor, that the motor may be swung to a convenient position to change cutters; and two aluminum locking angles mounted on the table T-bar to support the pivot studs centred at table level to hinge the unit consisting of endplates, hardened T-bar and carriage carrying the motor, that they may be indexed in relation to the platform; the materials being cut by a right angle motor driving a circular razor or slitting saw chucked into the motor gearing, guarded and mounted on a vertical travel slide depth set by toggle lever and spring returned, moving up and down on the aluminum carriage of the bridge T-bar that slides with horizontal motion;
all bearings of motion consisting of round stationary fluorocarbon buttons and adjustable fluorocarbon buttons backed by a steel set screw locked in position by adhesive, to permit the carriage to slide at a constant distance above the pivot point for straight cutoff to size or for angled inside cutting of matboard, set to cutting measurement by two toggle clamps adjustable on the top bar.