US1960872A - Typewriter key action - Google Patents

Description

May`29, 1934. R. GROVE TYPEWRITER KEY ACTION Filed May 16, 1931 2 Sheets-Sheet l n venan' A llorney May 29, 1934. R GRQVE 1,960,872

TYPEWRITER KEY ACTION Filed May 16, 1931 2 Sheets-Sheet 2 J/ Inventor @L P/f 6% op@ Homey Patented May 29, 1934 UNITED s'm'nssv PATENT OFFICE 2 Claims.

This invention relates to improvements in keyboard machines, and more particularly to a key operated action therefor.

The primary object of the invention resides in a key actuated mechanism in which the power transmitted to the type bars will be uniform.- regardless of the key touch of an operator, whereby the type impressions upon a sheet of paper placed in the machine will be of a uniform shade.

Another object of the invention is to provide a keyboard key actuated mechanism by which an operator may use a light touch in the actuation thereof to obtain the right shade of printing when a typewriter is connected thereto, thus requiring less skill and energy on the part of the operator to produce neat and uniform work.

A further object of the invention is to provide a keyboard key actuated mechanism in which the type bars are normally held under even spring tension, and which are released by key actuated trigger means, whereby the springs will swing the key bars against the platen, there being automatic means to reset the trigger means after each typing operation of the type bars.

A further object of my invention is to provide a power driven silent light touch key mechanism which can be attached to a standard typewriter in such a way that the operation of the power driven mechanism will operate the keys of the typewriter.

With these and other objects in view, the invention resides in the certain novel construction, combination and arrangement of parts, the essential features of which are hereinafter fully described, are particularly pointed out in the appended claims, and are illustrated in the accompanying drawings, in which:

Figure 1 is a side elevational view of a keyboard with parts broken away showing my improved key operated action incorporated therein.

Figure 2 is an enlarged vertical sectional view through one of the key actuated mechanisms.

Figure 3 is a detail vertical sectional view on the line 3-3 of Figure 2.

Figure 4 is a detail top plan view of a plurality of the releasable yoke members. Referring to the drawings by reference characters, the numeral 10 designates a conventional form of typewriter which includes a frame structure 11, a rotatable platen 12, a type bar 13 adapted to strike against the platen 12 and which type bar is operatively connected to a type rod 14, which in turn is actuated by alever 15 pivoted at the rear of the machine and extending forwardly thereof. The structure just described is old andv well known in the art and the invention now to be described relates to a means for imparting actuation to the lever 15 in order to operate the type bar 13 to swing the same lto printing position against the platen 12.

Although I am about to describe the construction and operation of one of the key actuated mechanisms, it will beunderstood that the typewriter is provided with an identical mechanism for each type bar of the machine and the mech? anism is arranged in a frame A on which the typewriter rests, as shown in Figure 1. The numeral 16 designates a key lever, the manipulating end of which is provided with a key 17, while the opposite end is formed with an extending finger 18. The key lever 16 is pivotally mounted between its ends upon a shaft 19 and which shaft supports all of the key levers disposed on that particular plane. By reference to Figure 1 of the drawings,

it will be noted that the rows of key levers are arranged in stepped formation as on the ordinaryA key board of the present style of typewriter, but

in each instance, the lever is pivoted centrally so as to be substantially on balance. A vertically disposed plate 20 is mounted in the frame A and 80 is provided with elongated slots 21 through which the inner ends of the levers 16 extend.

Slidably mounted in spaced bearings 22 is a vertically disposed weighted actuating bar 23 provided with shoulders 24 for abutting engagement 85 with the bearings 22 to limit the vertical sliding movement of the actuating bar in opposite directions. 'Ihe bar 23 is provided with a notch 25 for the reception of the finger 18 of the key lever 16 whereby depression of the key lever 16 will 90 impart a vertical sliding movement to the actuating bar 23 and which bar is adapted to drop to normal position under its own weight in a manner and for a purpose to be presently explained. 95

The upper end of the actuating bar 23 is provided with a semi-circular shaped socket or recess 26 for receiving the spherical head 27 provided on one end of a trigger 28 pivotally mounted upon a shaft 29 which shaft is supported by 100 the frame structure of the machine.

Pivotally mounted upon a bar or' rod 30 supported by the frame structure o1' the machine is the outer end of a yoke member 31 and which yoke member has its free end provided with a tongue 32' which when the lever is in a raised position, is disposed directly above the upper end of the actuating bar 23. 'Ihe yoke member 31 is provided with an elongated slot 33, while the trip member 28 when in a set position engages 110 the under side of the yoke member 31 adjacent to the edge of one of the end walls of the slot 33 so that if the trip member 28 was swung outwardly, the -yoke member 31 would be released and dropped to the dotted position shown in Figure 2 of the drawings.

Fixedly supported above the yoke member 31 and in substantial alinement with the actuating bar 23, is an angle bar 34 which is provided with ears 35 which support a cross pin 36- and which ears also Aact to guide the vertical sliding movement of an elongated plate 37. The lower end of the plate 37 extends through a slot 38 in the horizontal ange ofthe angle bar 34 and which end of the plate is vrounded and normally'rests upon the tongue 32 of the trip member 31. The plate 37 is provided with-a vertical elongated slot 39 through which the pin 36 passeskwhile extending from one side of the plate 37 is a` hook.

40 with which one end of a contractile spring 41 connects, while the opposite end of the spring is xedly connected to the horizontal flange of the angle bar 34. When the mechanism is set, as shown in full lines in Figure 2 of the drawings,

' the spring 41 tends to exert a downward pull upon the plate 37 for exerting a like pull upon an arm 42. The arm 42 is provided with a pin 43 for reception in a slot '44 provided in the upper end of the plate 37 and which slot opens on one side of the plate. The upper end of the arm 42 is fixedly connected to the lever 15 of the type bar actuating mechanism whereupon the downward pull upon the arm 42 will cause actuation of the lever 15 to swing the type bar 13 into typing engagement with the platen 12. This action of course takes place upon the actuation of the key lever 16 which releases the trip member 28 to permit the tension of the spring 41' to exert the desired power and impulse to the type bar actuating lever 15. For the purpose of resetting the yoke member 31, I provide a cam 45 which lis mounted on a shaft 46' supported by opposite walls of the slot 33 of .the yoke member 31. This cam member 45 is provided with spaced pins '46, one of which extends beyond the side of the cam member and constitutes a stop pin 47- adapted to abut a stop plate 48 mounted upon the frame of the machine, and which plate is disposed above the cam member 45. The stop plate 48 is provided with depending finger 49 with which the stop pin 47 is adapted to engage when the yoke member 31 is in a set position for the purpose of preventing` accidental movement of while the motor shaft is provided with a gear 53 in constant mesh with a larger gear 54 fixed to a shaft 55 extending lengthwise of the machine, and which shaft is on the same horizontal plane as the shaft 50. The gear 54 is in constant mesh with a gear 5d of the same size, and which gear 56 is fixed to the aforementioned shaft 50 whereby power is transmitted from the motor to the shaft 50 in order to impart continuous rotation to the toothed wheel 51. It will be understood that there is a toothed wheel 51 for each key actuated mechanism, while similar toothed wheels 51 are mounted on the driven shaft 55 as in practice, the trip mechanism for the respective type bars of the machine will be disposed on opposite sides of the vertical axis of the actuating bars 23.. This facilitates a compact structure to accommodate all of the key actuating mechanisms of a standard typewriter. Assume that the key lever 16 has been depressed to actuate the trigger 28 to release the yoke member 31, whereupon the spring 41 imparts a downward pull to the arm 42 to operate the type bar 13 and during such downward movement of the yoke member, the cam member 45 drops so that' the teeth of the toothed wheel 51 engage the pins 46 of the cam member, and in so doing, the cam member is rotated and by reason of its shape, the yoke member 31 is lifted to its set position against the action of the spring 41, and in order to arrest the movement of the cam due to its momentum, the stop pin 47 strikes against the stop fingers 49 provided on the plate 48. `'When the cam is in the position shown in full lines in Figure 2, the pins clear the teeth of the toothed wheel 51 and only engage the teeth of the toothed wheel during the time that the yoke member is in areleased or down position.

. From the foregoing description it will be seen that the spring 41 of each of the type bar actuating mechanisms'imparts the power to move the type bar into typing engagement with the platen and only a slight touch is necessary on the part of an operator to actuate the key lever 16 to release 105 the trigger member 28 which permits the spring 41 to function. Therefore a typewriter in which all the type bars are operated by a similar mechanism, will produce a uniform shade of printing irrespective of the touch or pressure imparted by the operator to the keys 17. The action of the coacting cam member and toothed wheel is rapid so that each key actuatingv mechanism is instantly reset after each' operation, and resetting is automatic due to the continuous rotation of the A115 vention, I wish it to be understood'that various changes in construction may be resorted to if de- 12g sired, and I do not limit myself to anything less than the whole of my invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Pat- 12h' ent is:- A

1. In a typewriting machine including the. key levers, a lug depending from eachlever, a frame under the typewriter, a transversely and horizontally arranged bar supported in the frame 1N under the lugs, a plurality of vertically arranged members supported by the bar for vertical movement and having their upper ends connected to the lower ends of the lugs, a spring connecting each vertical member with the bar and tending` to hold said member in its lowest position, a pivoted member in the frame for holding each vertical member in raised position, a latch member for holding each pivoted member in raised position, key operated means for moving each latch member to releasing position', and power operated means for raising each pivoted member after it has been lowered by operation of the vertical member by its spring when the latch member has been moved to releasing position.

2. In a typewriter including its key levers, a frame on which the typewriter rests, a lug depending from `each key lever, a horizontally and transversely arranged bar supported in the frame and having a plurality of openings therein, a plurality 180 of vertically arranged members supported by the bar for sliding movement and having their lower ends passing through the openings, means for detachably connecting the upper end of each vertical member to the lower end of a lug, a projection on each vertical member, a spring having its upper end connected with the projection and its lower end with the bar and tending to move the vertical member downwardly, a pivoted member in the frame for each vertical member and having a part for engaging the lower end of the vertical iso

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