US1698833A - Machine for cutting designs, letters, etc. - Google Patents

Description

Jan. 15, 1929. 1,698,833

T. TOWNSEND MACHINE FOR CUTTING DESIGNS, LETTERS, ETC

Original Filed July 8, 1924 v 2 Sheets-Sheet l FIG.1.

Jan. 15; 1929.

7 1,698,833 'r. TOWNSEND MACHINE FOR CUTTING DESIGNS, LETTERS, ETC

r inal Filed July 8, 1924 2 Sheets-Sheet 2 I Fl 13.3

' I ,5 A? //VVE/V70R WITNESSES M Patented Jan. 15, 1929.

UNITED STATES P ATE NT OFFICE THOMAS TOWNSEND," OF"PITTSBURGH, PENNSYLVANIA, ASSIGNOR F ONE-HALF TO HARRY F. ANDERSON, OF MARION, INDIANA, AND ONE-HALF TO JAMES BOYCE, OF

HOLLAND, MICHIGAN.

' MACHINE FOR CUTTING DESIGNS, LETTERS, ETC.

Application filed July 8, 1924. Serial No. 724,793.

In the manufacture of illuminated signs, the outlines of letters, figures or designs are formed through some opaque material, generally sheet metal. It has heretofore been the practice to cut'the outlines by means of shears, or ifthe metal sheet is thick, it has been necessary to employ cold chisels. As the outlines-are, infpart at least, irregular, there will be a bending ofthe edges of metal in turning the shears to form such. irregular outlines, and when employing cold chisels, the edges of the sheet will be more or less bent. In the completed-sign the edges of the opaque portion should be fitted closely 5 against the glasssheet back of'the opaque sheet, and hence it is the practice to. flatten the sheet in a press or by pressing it between rolls after the outline has been formed, to eliminate thebendsor kinks. But as the metal is more or lessstretchedwhen being bent by the shears or chisel, such rolling will only partially flatten the edges.

The object of the invention as described herein is to provide means whereby the outlines desired be cut in a sheet without any bending or stretching of the metal. The invention is hereinafter more fully described and: claimed.

In the accompanying .drawings forming a part of'this specification, Fig. lis an end elevation of the cutting mechanism claimed vherei'n:;--lii'g..2 is elevation of the opposite end of the mechanism; Fig. 3 is a top plan;

. and Fig. Lisa rear elevation of the mechanism; and Figs. 5 and 6 are side and edge views of a cutter.

In the practice of'the invention the cutter is not only driven but is also carried by an electric motoradapted to be shifted over the sheet operated on the motor, which may be of any suitable construction, is enclosed in a suitable shell or casing 1 provided at its ends with bearings 2 for the shaft 3 of the armature. Tofacilitatethe' sliding of the motor overthe-sheet, and to maintain the axis of the armature substantially parallel with the sheet, a plurality of supports are provided. In the construction shown, three points of support are provided, twoof such supports being in or approximately in alinement vertically with the axis of the armature shaft and the third support at one side of a line passing through the other two supports. One

' of said supports consists of a shoe formed by a. curved bar 4 having slotted fingers 5 at its ends and held in position by bolts 6 passing through the slots into the shell. The other shoe in alincment with the shaft of the armamounted in an extension of the handle 10 secured toone side of the shell or casing 1.

7 It will be apparent that by providing a support immediately adjacent the cutter and vertically beneath the cutter axis and a plurality of supports disposed from said first support axially of the cutter and adapted to permit movement of the tool transversely of the axis of the cutter,- the tool may readily be pivoted about vertical axes intersecting the cutter axis. These shoes are adapted to permit movement of the tool transversely of its axis and to resist movement along the axis so that in pivoting the tool the cutter Will roll peripherally in describinga curve rather than slideaxially. WVith this construction it is possible to cause the cutter to describe curves of extremely short radii.

It will be readily understood by those skilled in the art that in order to readily out along curved lines having short radii, the cutter. should have comparatively small diameter and as the cutter should be so mounted that a portion of its edge will project below the supporting points, its axis of rotation is below the 'axis of the armature and hence provision is made for transmitting motion from the armature to the cutter. In the construction shownherein the cutter 11 is secured on a shaft 12 mounted in a boss 13 projecting from the cover 14 of a box 15. On the inner end of the shaft 12 is secured a pinion 16 adapted to intermesh with an idler 17, the journals of which extend into openings in the box. and cover as shown in Fig. 4-; this idler intermeshes with a pinion 18 secured on the shaft 3 of the armature, said shaft extending through the upper portion of the box. While the box may be secured to the shell or casing in any suitable manner, the

construction shown has been found suitable hanging the cutter 11 secured as before stated on the shaft 12. To this overhanging portion 22 is secured one end of the bar 7 forming one of the supports of the mechanism. The curved portions 8 of this bar is slotted as at 23 permitting the lower portions of the cutter to project through and operate 011 the sheet. As before stated, the curved portion 8 bears on the surface of the sheetoperated on and provision is made for adjusting the position of the portion 8 of the bar relative to the cutter and thereby regi'ilate the depth of cut made by the cutter. Such depth of cut will vary in accordance with the thickness of gauge of the sheet operated on. The adjustment of the bar 7 can be effected in any suitable manner, as for example in the construction shown, one end of the bar 7 which is resilient, is secured to the portion 22 and the desired flexure of the free portion of the bar. is effected by a screw 24 passing through the portion 22 and bearing on the bar as clearly shown in Figs. 1 and 8. In order to facilitate the manipulation of the mechanism, it is preferred to employ an auxiliary handle 25 preferably secured to the overhanging portion 22 so as to be in approximate alinement with the cutter. In the construction shown, the bar 7 is secured to the portion 22 by the handle, the threaded end of the latter passing through the upturned end of the bar and screwing into the portion 22.

As the outlines to be cut in a sheet have curved portions. the radii of some of such curved portions being small, the width of the out should be greater than the thickness of the teeth in order that the cutter may be shifted to change the direction of out. As shown in Figs. 5, 6 and 7, the teeth are approximately pyramidal in shape, the front and rear faces, a and Z) having equal inclinations. The sides 0 and d of the teeth are, however, differently inclined as clearly shown in Fig. 7 The side 0 of tooth 0'0 being at an obtuse angle to the side of the body of the cutter, while the side (Z of the tooth forms a more acute angle with the side of the cutter. The inclination of the sides of an adjacent tooth 1 are the reverse of those of the sides of tooth m. By reason of thedescribed inclination of adjacent teeth, the. apices will be out of line peripherally and consequently the cut made in the sheet will permit of such shifting of the mechanism as will permit the following of curved lines.

It will be noted that the motor 1 constitutes the major portion of the framework of the machine and is of such size as to furnish the weight required to make the machine steady and free from objectionable vibration in the operation of the cutter. The parts 2, 3, 14, 15, 19 and 20 constitute frame means for supporting the cutter at a substantial distance from the motor. It will be understood that in cutting a curve of short radius, the motor end of the machine is swung through a longer are than if the cutter were close to the motor; consequently the motor end of the machine may be swung and guided with the required accuracy and precision more easily than if the arc was short. 7

In cutting a curve of larger radius, as, for example, one that extends toward the left in Fig. 3, the motor end of the machine would have relatively little movement of translation, the handle 25 being employed to push the cutter end of the machine along the required path.

I claim herein as my invention:

1. A machine for cutting a metallic sheet comprising an electric motor which constitutes the major portion of the framework of the machine and furnishes the weight required forsteadiness in operation, a relatively small rotary cutter frame means attached to the motor for supporting said cutter at a substantial distance from the motor, means for communicating power from the motor to the cutter, a support on said frame means adjacent to the cutter adapted to rest on the sheet being cut and adapted to permit the cutter to sever, the sheet, a handle on said frame means adjacent to said cutter for guiding the cutter end of the machine when the latter is turning on the sheet, two supports on said motor adapted to rest on the sheet being out, said supports constituting a threepoint support for the machine, permitting free turning movement of the machine on the sheet, and a handle on the motor for guiding the motor end of the machine in such turning movement.

2. A portable machine for cutting rigid sheet material comprising an electric motor which furnishes the weight required for steadiness in operation, a relatively small rotary cutter, frame means attached to the motor for supporting said cutter ata substantial distance from the motor, means for communicating power from the motor to the cutter, a support on said frame means adjacent to the cutter adapted to rest on the sheet being cut and adapted to permit the cutter to sever the sheet, a handle adjacent to said cutter for guiding the cutter end of the machine when the latter is turning on the sheet, two additional supports adapted to rest on the sheet being out, said supports constituting a three-point support for the machine, permitting free turning movement of the machine on the sheet, and a handle for guiding the motor end of the machine during such turning movement. 7

In testimony whereof, I have hereunto set my hand.

THOMAS TOWNSEND.

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