US2561453A - Friction devices for stenographic typewriter platens - Google Patents

Description

July 24,1951 H M. VON DUYKE FRICTION DEVICES'FOR STENOGRAPHIIC TYPEWRITER PLATENS Filed Oct. 28, 1947 Patented July 24, 1951 FRICTION DEVICES FOR STENOGRAPHIC F TYPEWRITER PIIAEENS Harrison M. Von Duyke, Wilmington, Del., as-

signor to New Dictatype Company, Inc'orpo rated, Wilmington, Del., acorporation'of Dela ware Application. October.28, 1947;,Serial No. 782,473

This invention relates to friction devicesfor stenographic typewriter platens, that is to. say, to devicesladapted to be used in connection with the paper. feed of stenographic typewriters, forthe purpose of enhancing the frictional engagement between the paper and the platen, whereby the paper will be fed uniformly as the platen rotates with a step by step motion during the operation of themachine;

Heretofore, in typewriters, both of the ordinary-tr peand the stenographic type; various devices have been used for the purpose of enhanc ing the frictional engagement betwecntthe paper and the platen, for the purpose of insuring-.the proper feed of the paper when the platen is rotated. Such devices customarily comprise small rubber rolls, .variously located to impel the paper againstlthesurface of the platen to causethe same to be fed in unison with the step by step rotation of the platen.

However, when such devices are made of r-ubher or the like, they become hardened in the course of time and fail to function properly.

Furthermore, in typewriters of the stenographic type, in which the platen is usually much shorter than in the ordinary typewriters, it is more difficult to provide a satisfactory device of this character, which will be sure and positive in its action, and which will not wear or deteriorate in the course of time.

Also, in stenographic typewriters, the paper is usually provided in strips, folded in what is known as a fan fold, so that variations in the gripping action occur as the paper-is fed over the platen, particularly where the creases occur.

The principal object of the present invention is to provide improved means, particularly adaptable for use in stenographic typewriters, for enhancing the frictional engagement between the paper and the platen.

A further object of the invention is to provide, in a machine of the character aforesaid, a device which will at all times maintain the proper frictional engagement between the platen and paper, notwithstanding irregularities which occur due to the difference in paper thicknesses and when the creases in the paper strip pass over the platen.

A further object of the invention is to provide, in a machine of the character aforesaid, a device which continues to function and will not deteriorate in the course of time, notwithstanding the fact that the peripheral travel of the paper over the platens of the stenographic typewriters is considerably more than that in the ordinary typewriters.

2 Claims. (C1. 197 -138),

The; nature. and characteristic features. of the presentlinvention will be more readily understood fromthefollowing description, taken in connection with the accompanying drawing forming part hereof, in which:

Eigure 1 is a perspective view of a deviceembodyinglthe main features of the present invention, the. same, being shown. in connection with platen of a stenographic typewriter;

Fig. Zisaverticalcentralsection thereof; and

Fig. a top orplan view of the principal portion of the device detached.

It should, of. course, be understood that the description and. drawing herein are illustrative merely, and that various modifications and changes may be made in the structureclisclosed without departing from the spirit of "theinvention';

Referring to the drawing, there is therein shown the side plates 5 of the frame of a stenosuitable frame i2 comprising two side plates I3 and a spacing .bar it extendingtherebetween.

The side plates 13 of the frame 12 are pivotally mounted on a transverse rod l5. The frame [2, and rollers 8 carried thereby, are positioned intermediate the ends of the platen 6 by means of split washers l6, which engage suitably located rooves IT in the rod I5.

The lower marginal edge Id of each of the side plates 13 of the frame I2 is complemental in shape to the surface of the platen 6, and these edges l3 are spaced a slight distance from said surfaceso that the side plates E3 of the frame I2 not only serve to support the rollers 8, but also act as guides for the front edge of the paper when the same is being initially fed therethrough.

The transverse rod i5 is mounted, at each end, with a more or less loose connection, on the free end of a link I8. Each link It is pivotally mounted on one of the side plates 5 of the frame work of the machine by means of a pin l9.

On each side of the machine there is provided a coil spring 20, one end of which is connected to side plates of the frame work of the machine are so located with respect to the axis of the platen;

and the coil springs 20 are so positioned, that the grooved rollers 8 will be pulled forwardly bythe springs 20 with a wedge like action so that a proper and sufficient pressure will be exerted on the paper passing over the platen 6 without unduly stressing the springs 2|].

By the foregoing arrangement there is provided to the platen, a frame work carrying'said rollers; a transverse rod upon which said frame work is pivotally mounted, links in which said transverse rod is loosely mounted at the ends thereof, and a coil spring on each side of the machine for impelling said rod forwardly, each of said coil springs being connected at one end to one end of said rod and at the other end to the frame work of the machine.

2. In a typewriter having a platen over which thepaper passes during the operation of the machine, means for enhancing the frictional enga'gement of the paper with the platen comprising a pair of grooved metallic rollers bearing against a device for enhancing the frictional engagement:

between the paper and the platen of a typewriter, which is particularly adaptable for use on' stenographic typewriters, which will be durable and eflicient, and which will readily adjust itself to such variations as occur from time to time, and particularly when the creases in the paper pass over' the platen.

The connections between the transverse rod which supports the friction rollers and the spring controlled arms upon which the ends of the transverse rod are mounted are preferably of a loose character so that the friction rollers may readily adjust themselves to such irregularities as occur in the operation of the machine.

I claim:

1. In a typewriter having a platen over which the paper passes during the operation of the machine, means for enhancing the frictional engagement of the paper with the platen comprising a pair of grooved 'metallic rollers bearing against and spaced circumferentially with respect and spaced circumferentially with respect to theplaten, a frame work carrying said rollers, a

' transverse rod upon which said frame work is pivotally mounted, links for supporting said. transverse rodat the ends thereof, and a coil REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 833,840 Kunath Oct. 23, 1906 2,059,214 Dreher Nov. 3, 1936 2,319,273 Sterling May 18, 1943 Smith Apr. 24, 1947

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