US408150A - Freeman l - Google Patents

Description

(No Model.)

F. L. TWISS. 0AM MOTION FOR TYPE WRITING MACHINES.

No. 408,150. Patented July 3-0, 1889.

WITNESSES: A INVENTDR M i N. PETERS, Phm-Lnhc u lwr. Washinglon. I) C UNTTED STATES PATENT OFFICE.

FREEMAN L. TNVISS, OF GROTON, NE\V YORK, ASSIGNOR TO THE CRANDALL TYPE-VRITER COMPANY, OF SAME PLACE.

CAM-MCTION FQR TYPE-WRITING MACHINES.

SPECIFICATION forming part of Letters Patent No. 408,150, dated July 30, 1889.

Application filed January 9, 1888. Serial No. 260,157. (No model.)

To aZZ whom it may concern.-

Be it known that I, FREEMAN L. Twiss, of Groton, in the county of Tompkins, in the State of New York, have invented new and useful Improvements in Cam-Motions for Typeritin g Machines, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to animprovement in cam-motions for type-writers; and it consists in certain peculiarities of the construction and operation of the same, substantially as will be hereinafter more fully set forth and claimed.

In order to enable others skilled in the art to which my invention pertains to make and use the same, I will now proceed to describe its construction and operation, referring to the accompanying drawings in which Figure 1 is a longitudinal vertical section of a part of the frame of a type-writer, showing the parts of my invention as they are when normal and at rest. Fig. 2 is a similar view showing the position of the parts after the strokeis finished or at the end of the forward stroke; and Fig. 3 is a vertical cross-section of the main frame, showing the actuating parts in elevation. But one key and its accompanying devices is shown in any View; but it will be understood that this is for clearness, and that as many keys will be used as are desirable, and that all will be simply a duplicate of the one herein shown.

My invention relates to that class of typewriters in which there is a type-cylinder carried upon a pivoted arm and thrown forward against the impression-cylinder when the key is depressed; and my object is to so construct the moving parts interposed between the key and the type-cylinder that the initial movement of this cylinder will be quite slow and easily operated and its motion increased gradually in speed as the inertia is overcome, and at the end oft its stroke deliver the impression at proper speed and force to make it clear and plain, and also to prevent any recoil of the type-cylinder after delivering its blow till the pressure is removed from the key. All this I accomplish as follows:

a represents the main frame of a typewriter of any desired and suitable form, and a is one of the pivoted key-levers. This will of course be shaped to lit the particular machine in which it is used, but is herein shown as a plain pivoted bar, which serves everypurpose of this case.

The type-cylinder Z) is held in a yoke 11, pivoted to a bracket on the main frame, and all these parts are made and used as has been usual in this class of machine, and therefore do not require any further description herein.

In proper supporting standards or brackets c on the base of the machine I journal a rockshaft 0, on which is secured a yoke 0 resting upon the rear end of the key-lever, and lifted thereby to rock the shaft when the key is 0perated, as will be clearly seen in the drawings. Upon this rock-shaft is also secured a camfaeed arm d, having a shallow notch cl in its end, which arm lies normally in contact with an arm 6, secured to the yoke or pivoted frame which carries the type-cylinder. This latter arm is provided with a pin 6, for engagement with the notched end of the cam-arm d, and is also formed with an inclined face or bearing-surface 6 for contact with the face of the cam.

By reference to Fig. 1 it will be seen that the parts lie normally with the type-cylinder thrown back, and the pin 6' in engagement with the notched cam-arm. \Vhen the key is depressed by the operator, the rear end of the key-lever rises andlifts the yoke 0 rocking the shaft 0 in its bearings. This throws back the cam-arm, and as it bears against the arm 6 the latter is also forced back, rocking the yoke b and throwing the type-cylinder forward.

It will be noted that the normal bearingsurface of the cam-arm is nearly straight, and is formed with a gradually-quickening curve from this point to its end. This peculiar formation starts the type-cylinder forward very slowly; but the motion is increased as the curved surface of the cam is brought into 5 use till the end of the stroke is made quickly, and with a force sufficient to form a proper impression, and at the end of the stroke the parts assume the position of Fig. 2, where it will be seen that the pin (1 has passed out of the notched end of the cam-arm and lies behind it. The end of the cam therefore lies between this pin and the inclined face of the arm 8, and forms a sufficiently rigid connection to prevent. any recoil of the type-cylinder on making the impression. As soon as pressure is removed from the key, the parts fall back to their normal position, as seen in Fig. 1.

As before stated, the drawings herewith 'show but one key; but all the keys necessary for use will be similarly fitted.

The gradual starting of the type-cylinder and its quick finish make the operation of the key very easy and of even force throughout, as but little force is needed to overcome the inertia of the cylinder at low speed, while the change of bearing upon the face of the cam while in motion produces the increased speed, and as it at the same time gives the key a correspondingly-increasing leverage no additional pressure is needed to operate it, and the force applied is even and regular through the whole stroke.

Having thus fully described my invention,

what I claim as new, and desire to secure by Letters Patent, is

1. In a typewriter, the combination, with a type-cylinder and a pivoted yoke for carrying said cylinder, provided with a stop-pin and an inclined bearing-face, of a cam-arm having its face formed with a gradually-increasing curve, and its end adapted to lie between the stop-pin and inclined bearing-face'at the end of the stroke to prevent recoil, substantially as and for the purpose set forth.

2. In a type-writer, the combination, with the main frame a, key-lever a, type-cylinder b, and its pivoted carrier 1), provided with the arm 8, having the bearing-face e and pin 6', of the rock-shaft 0, its yoke c and the notched cam-faced arm (Z, all constructed and arranged to operate substantially as and for the purpose set forth.

In testimony whereof I have hereunto signed my name, in the presence of two attesting Witnesses, at Groton, in the county of Tompkins, in the State of New York, this 24th dayof December, 1887.

FREEMAN L. TWISS.

W'itnesses:

FLORA RHODES, D. H. MARSH.

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