US1688364A - Automatic typewriter - Google Patents

Description

Oct. 23, 1928. I 1,688,364

R. G. THOMPSON AUTOMATIC TYPEWRITER Filed Dec. 5, 1926 4a 2a i Ji 1 Q 235 '39 l M? 45/ MO ts I as 47 38 Patented a. 23, 1928.

UNITED STATES 1,688,364 PATENT OFFICE.

RUSSELL G.. THOMPSON, OF ROCHESTER, NEW YORK, ASSIGNOR TO NORTH EAST APPLI- ANCES, INQ, OF ROCHESTER, NEW YORK, A. CORPORATION OF NEW YORK.

AUTOMATIC TYPEWRITER.

Application filed December 3, 1926. Serial No. 152,484.

This invention relates to automatic typewriting machines of the kind used for makmg numerous copies of form letters.

It has been found that advertising circulars or form letters having the appearance of 1ndividually typewritten communications are more effective than circulars which are printed or obviously manifolded. In order to produce such-letters economically, it is customary to write them upon typewriters of ordinary construction, the' type, mechanisms and other functional parts of'the machine being actuated by power mechanism operatlve selectively'and automatically, under the control of-selecting mechanism in which a perforated paper strip is used as avpattern.

When a letter is written by an automatic machine, it is still necessary that at least the name and address of the recipient be individually written, and this is commonly done by stopping the automatic mechanism at the proper point and operating the typewriter manually in the usual way. "The result of this method is not entirely satisfactory, for the reason that it is impossible to make the manually written parts of the letter indisil tinguishable from the automatically written body. :The automatic operation of the machine resultsin writing whichis perfectly uniform in the strength of the impressions, whereas themanually written portions are necessarilysomewhat variable, and the difference is perceptible.

Another feature of automatic typewriting machines as heretofore proposed, is the fact that the automatic selecting means are utilized also as the means for applying power to the type-bars and other parts, with the result that the selecting means must be rugged in construction, and that if designed to operate rapidly and with precision they subject the pattern sheet or strip to considerable wear. 1 .v 1

One object of the present invention is to produce a typewriting machine capable of operation both automatically and manually, in which the manually controlled writing is absolutely indistinguishable from that which is automatically controlled; and another obj ect of the invention .isto produce a machineof this kind in which the operation of the automatic selecting mechanism may be so delicate as to sub ect the pattern-sheet to a minimum ofwear.

Both ofthe foregoing objects are attained by an arrangement in which the type-bars or other parts are operated selectively by power mechanism which is functionally independent of both the selecting mechanism and the manually operable keys, and in which these latter parts act only to control the power mechanism, but not to transmit any part of the power by which the functions of the typewriter are performed.

In the accompanying drawings, Fig. ,1 is a side-elevation, partly in section, showing, in a partly diagrammatic manner, the essential elements of a machine embodying the present invention. Fig. 2 is a detail side elevation on a larger scale, showing particularly the essential. parts of the automatic selecting mechanism. Figs. 3 and 4 are, respectively, a side-elevation and a front-elevation of one of the cam-units of the power mechanism.

The invention is illustrated as embodied.

in a machine having type mechanism of a well known form. The several types are carried on type-bars 10, of which only one is shown, the type bars. being pivoted at 11. Each type-bar is actuated by a bell-crank lever 12, pivoted at 13 on the frame of the machine. The types cooperate with the usual platen 31. y

The particular form and mode of operation of'the power mechanism by which the type-bars are actuatedisnot important, but

cam lever is formed, at'its forward part, of

two spaced side plates between which a cam 18 is pivotally mounted, this cam having two similar serrated lobes of increasing radius. Projecting from the side of the cam are two, diametrically opposite pins 19, which cooperate with a spring-pressed arm 20, which swings on a pivot 21 mounted in the side plates of the cam lever. In the normal position of the parts the cam is just out of engagement wlth the powerroller, but the spring arm 20, acting against one of the pins, tends constantly to impart a sutficlent rotation to cause the cam to swing into engagement with the roller, and when this occurs a part rotation is imparted to the cam and this, owing to the increasing radius of the cam lobe, causes the cam lever to rock sufficiently to actuate the type bar and cause an impression.

The movement of the cam is'controlled by escapement mechanism including two diametrically opposite stop-lugs 22, projecting from the periphery of the cam. These stoplugs cooperate with detents 23 and 24 projecting from a detent lever 25, which also swings upon the pivot 21. The ,upper arm 26 of the'detent lever has a lateral projection 27, which is embraced by the forked extremity of an arm 28 constituting part of a key lever 29. This lever is pivoted at 30 on the frame of the machine, and a. spring 32, connected with the lever, acts normally to hold the parts in a position in which the de tents 23 and 24 may cooperate with one or the other of the stop-lugs 22. Normally the stop-lug engages the detent 24, but when the corresponding key lever isdepressed the detent lever swings forwardly, thus disengaging the detent 24 from the stop-lug and permitting the spring arm 20 to throw the cam into operation. At the end of a half rotation, however, the cam is arrested by engagemcnt of its other stop-lug with the detent 23.

When the key lever is subsequently permitted to return to normal position the detent 23 disengages the stop-lug, which is then ar- A rested, after a slight rotative movement of the cam, by the detent 24, and the parts are then in position for renewed operation.

The automatic selecting mechanism may be of various forms, but it is shown herein as controlled by a perforated paper strip in the usual manner. This mechanism comprises a roller 34, which may be driven constantly from the same source of power as the power roller 14. For this purpose the two rollers are inter-connected by a shaft 35, geared to them as shown in Fig. 1. The shaft is made in two parts, connected by a clutch 36 which may, be operated, by any ordinary or suitable means, to disconnect the selector roller 34 from the source of power whenever the automatic operation is to be interrupted.

The paper pattern sheet or band 37 hangs loosely over the selector roller, and the roller is provided, in the usual manner, with pins 38 engaging suitable marginal perforations in the paper to maintain correct registration and secure a positive motion of the paper. The roller is longitudinally grooved, as shown in Fig. 2, and the select ing perforations in the paper are arranged to register with the grooves. Corresponding with each cam-unit of the power mechanism is a selector .unit comprising a-star-wheel 39, rotatably mounted on the forward end of a lever 40. The selector levers 40 are pivoted, at 41, on the frame of the machine.

Associated with each selector lever is an arm 42, also mounted on the pivot 41 and having a lug 43 which rests normally against an arm 44 on the lever. A spring 45, connecting the lever and the arm 42, normally mainselector roller 34. The roller then causes a positive "rotation of the star-wheel through 90, and this results in a swinging movement of the selector lever, as shown in dotted lines in Fig. 2. The corresponding arm 42 participates in this movement, and since the arm is provided with a lug 46 which overhangs the corresponding key lever 29, the key lever is depressed and this results in throwing the corresponding power unit into operation, as before described, whereupon the type-bar connected to that power mechanism is operated.

It will be obvious that other operative elements of the typewriter may be actuated and controlled in the same manner as the typebars.

When it is desired to write a portion of the letter under manual control the automatic selecting mechanism may be thrown out of operation by means of the clutch 36. For manual control each key lever 29 is provided with a finger key 48. WVhen one of these keys is depressed the corresponding key lever is actuated, and it throws the corresponding power unit into operation.

It will be evident that whether the key lever be depressed manually or by the action of the selecting mechanism, the effect upon the type-bar is precisely the same, by reason of the fact that the key lever does not in any case impart any motion to the type-bar. On the contrary, the actuation of the typebar is always performed by its correspond, ing cam-unit, and the force imparted to the bar .by the cam-unit is constant so long as the speed of rotation of the power roller 14 does not vary. In operating the key levers manually,'therefore, it is impossible to impart any distinguishing characteristics to the matter so written.

It will also be evident that in this machine the amount of power required to depress the key lever is much less than that necessary where the key lever transmits to the typebar the power necessary to actuate the latter. Consequently, the automatic Selecting mechanism may be made very light and delicate in its parts, so as to subject the paper strip or pattern to very little pressure and wear, and thus a large number of letters may be write 5 ten Without renewing 'or repairing the pati tern strip. The-machine is also capable of hi h speedfor the same reason.

The invention claimed is: In an automatic typewriter, the combina- 10 tion of a series of key levers, a series of printing' iristrum'entalities corresponding to said the. key levers to move them in a predeter- 20 mined sequence.

RUSSELL G. THOMPSON.

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