US2223036A - Typewriting machine - Google Patents

Description

1940- w. F. HELMOND 2,223,036

IYPEWRITING MACHINE Filed June 27, 1938 2/ INVENTOR WILLIAM FZHELMOND 1" l/ BY Patented Nov. 26, 1940 UNETED STATES PATENT QFFICE TYPEWRITING NIACHINE Application June 27,

7 Claims.

This invention relates to typewriting machines and, with regard to certain more specific features thereof, to typewriter keys and to the means for attaching the keys to the key levers. The invention is particularly applicable to typewriter keyboards in which keys of molded rubber coinpound, or phenolic condensation products, or the like, are used.

The invention has for one of its objects to provide for the ready interchangeability of key caps with their proper rotative position assuredly maintained.

It is a further object of the invention to provide a key lever stem of simple and inexpensive construction upon which a key may be quickly and conveniently located or from which it may be detached, with provision for preventing any looseness in the connection.

It is a still further object of the invention to provide a simple, inexpensive and readily attachable and detachable masking member to give the key-support or stem a finished appearance.

This invention is in some respects an improvement upon the one shown in my copending application Serial No. 127,609, filed February 25, 1937.

In the accompanying drawing wherein are shown various possible embodiments of the in- Vention:

Fig. 1 is a View in front elevation partly broken away showing a key lever assembly embodying the invention in a preferred form.

Fig. 2 is a side view of the key lever assembly shown in Fig. 1.

Fig. 3 is a view in perspective showing the key lever assembly of Figs. 1 and 2, with the parts detached.

Fig. 4 is a schematic view showing the key lever stem and the key cap and indicating the manner in which the key lever stem is manipulated to receive the cap.

Fig.5 is a view corresponding to Fig. 1 but showing a modified construction of key lever stem.

Fig. 6 is a view in perspective showing another modified construction of key lever assembly, and

Fig. '7 is a fragmentary View of a keyboard showing a number of keys assembled according to the present invention.

Referring now more particularly to the drawing, a key lever is indicated at 10. On its forward end, as shown clearly in Fig. 3, there is spot-welded or otherwise suitably fixed a key lever stem II which is formed of a single piece or strip of spring metal formed in U-shaped with 1938, Serial No. 215,993

its upper ends flared as indicated at 12. The channel of the U is of a width to suitably fit a key lever for the spot-welding operation, and a space above the forward end of the key lever provided by the channel of the U-shaped strip permits the tines 13 of the strip l l to be pinched together, as shown clearly in Fig. 4, in order that they may receive a key cap l4 having a rectangular recess l5 into which, in the molding operation, a metal reinforcing member 16 has been embedded. By curving the metal reinforcing member I6 at either end grooves I! are provided to receive the tips or flared portions l2 of the U-shaped channel member H. As the tines are released from their pinched position the tips I2 spring tightly into the grooves and tightly unite the parts.

By the particular structure of the key stem of the present invention the assembly is considerably simplified and reduced in expense over the one shown in my copending application herein above referred to.

The tines 13 of the channel member II have their external faces provided with recesses l8 to receive opposed edges 20 of a channel shaped resilient clasp in the form of a split masking tube 2|. This tube bridges the space between the tines l3 and is preferably of spring steel or other suitable spring material and is of proper size and resiliency to be forced over the key lever and stem assembly from the bottom upwardly so that the edges 29 will first be forced apart and subsequently close in to the grooves or recesses 18 in the stem and fit tightly therein, thus conveniently masking the key lever stem and its association with the forward end of the key lever and providing a good appearance for the assembly.

In Fig. 5 a modification is shown in which projections 22 are formed on the inner sides of the tines l3 of the key lever stem. These projections preferably are stamped or punched from the fiat metal of the strip so that when the strip is bent to U-shaped the projections will abut at some distance above the key lever. Thus the resiliency of the tines is counteracted and thinner metal stock may be used, if desired, to the end of cutting down cost.

The invention is also adaptedto the type of key lever assembly in which the key cap is offset or out of alignment with the center line of the stem. The modification of the invention shown in Fig. 6 provides for such a condition. In that figure the assembly of the key lever and stem is. substantially the same as in the other showings but the tines l3 at their upper ends are given an offset in parallelism and then flared, as indicated at 23. In such case the masking tube is given a lateral offset 24 so that the shrouding of the ofiset key stem will be complete.

What is claimed is:

1. In a key-lever assembly, a key-lever, a keycap, tines extending upwardly from the said lever for supporting the said key-cap and provided with recesses, and a channel-shaped resilient mask-member concealing said tines from view, including, means to resiliently engage the said tines in the recesses.

2. In a key-lever assembly, a key-lever, a keycap, tines extending upwardly from the said lever and having offsets at the top to support the said key-cap in offset relation, a mask-member for said tines, said mask-member comprising a vertical, channel-shaped clasp-portion concealing said tines from view below the said ofi'sets and a lateral fiat extension concealing the ofi'sets of the said tines from view, and cooperative means on said tines and said clasp-portion to locate said mask-member in masking position.

3. In a key-assembly for typewriters or the like, in combination, a key-cap, parallelly spaced tines of substantially uniform cross section supporting the said cap, a clasp constituting an elongate mask clasped to the said spaced tines and concealing them from view, and cooperative means on said tines and said clasp to locate said clasp ing the said cap and being'provided with recesses on two opposite flat sides, a channel-shaped resilient clasp bridging the space between the tines to thereby conceal the spaced tines from View, said clasp having edges resiliently engaging the sides of said tines in said recesses.

5. A key-assembly having in combination, a key-cap, a pair of fiat-sided spaced tines supporting the said cap, the outer sides of said tines facing from each other and being each provided with a lengthwise groove, a channel-shaped resilient clasp bridging the tines to thereby conceal the spaced tines from view, said clasp having edges resiliently engaging the sides of said tines in the said grooves.

6. In a key-assembly, a key-cap, a. support for said cap, comprising two flat-sided, parallelly spaced spring-tines that are rigidly connected at one end and hold said cap at the other end by springing outwardly with strong tension, a masking clasp in the form of a resilient'channel-member clasped to the outer sides of said tines and bridging the space between the tines to conceal the tines from view, said channel-member being easily flexible and therefore having a negligible influence on the outward cap-holding tension of said tines, and cooperative means on said tines and said clasp to definitely locate the said clasp in masking position.

7. A key-assembly having in combination, a key-cap, a pair of spaced tines supporting the said cap, a clasp in the form of an elongate mask concealing said tines from View, and'cooperative means on said tines and said clasp to hold said clasp in masking position upon the tines.

' WILLIAM F. 'I-IEIMOND.

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