US2134845A - Typewriting machine - Google Patents

Description

Now. i, 1938. J. A. B. SMITH 2,134,845

TYPEWRITING MACHINE Filed Dec. 21, 1955 v INVENTOE:

2] BY I,

Patented Nov. 1, 1938 Q UNITED STATES PATENT OFFICE TYPEWRITENG MACHINE Jesse A. B. Smith, Stamford, Conn, assignor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application December 21, 1935, Serial No. 55,503

4 Claims. (Cl. l97103) This invention relates to the keys of type- No. 2,059,615) there was a requirement for diviwriting machines. sion of certain of the subject matter contained in This invention discloses a very light, compact, the present application as filed. Further .division fabricated key having a metal key-cup, secured having been required, said subject matter is now to the key-lever, and an annular metal cap, contained in my co-pending application Serial struck up of thin metal, removably secured to No. 195,717, filed March 14, 1938.

the key-cup; said cap having a comparatively Other features and advantages will hereinafter narrow, inwardly turned brim by means of which appear. a preferably multi-ply character-disk is secured in the accompanying drawing it in position in such manner as to have an unsup- Figure 1 is a perspective of a portion of a typeported central portion. writer-key-bar with a key mounted thereon.

In one embodiment of the invention, a char- Figure 2 is a sectional view of the key construcacter-bearing disk rests, entirely within the keytion, illustrating the concavity of the central cup, on a flat-topped annular ring struck out of area due to finger pressure.

i5 fibre or similar material. overlying the char- Figure 3 is a sectional view of a slightly modiacter--bearing disk, a protective contact disk of fied form of Figure 2. hard, transparent Celluloid is placed, having a Figure 4 is a detailed perspective of the disasdiameter equal to the outside diameter of the sembled key of Figures 1, 2 and 3. key-cup. The disk rests on the edge of the key- Figure 5 is a representation of the key of Fig- :70 cup, ure 3, showing the central area flexing under The metal cap is formed with a narrow, infinger pressure. turned brim, which pinches the Celluloid disk Referring to Figures 1 and 4, 20 represents a tightly against the edge of the key-cup, and typewriter-key-bar having an upwardly extendserves frictionally to hold the character-bearing ing stem 21'. A key-cup 22 is formed with a recdisk in position, preventing its accidental rotatangular socket 23 to engage the stem tightly and 25 tion in use. has a circular base 24 and an upwardly extend- The character-disk is housed completely withing rim 25, forming the cup. in the key-cup, and is not subjected to sharp An annular ring 26, Figure 4, which may be bending. It can therefore be made of very inpunched out of vulcanized fibre or other suitable 3 expensive materials, such as stiff, heavy paper, material is formed to fit snugly within the keyetc. cup on the bottom thereof, and forms a base for The contact surface of the key is normally fiat, a character-bearing disk 21 on which is printed but there is an unsupported or partially supa character 28. The width of the ring 26 is suifiported central area and the ,yieldable contact cient to provide a substantial supporting surface :3 disk and character-disk form a cushion-like confor the disk 21, as illustrated in Figure 2, and its struction, which may yield slightly into the openheight, plus the thickness of the disk, is prefering of the annular support, on being struck. ably equal to, or slightly greater than, the depth The annular flange or brim of the key-cap is of the key-cup. very narrow, it being necessary only to extend A protective disk 29 of thin, hard, transparent in over the edge of the key-cup. A large effective material, such as Celluloid, having a diameter contact area is thus provided, making it possible, equal to the outside diameter of the key-cup 22, if desired, to reduce the overall diameter of each is formed to overlie the character-disk 21 and key without reducing the size of the character, or serve as a protective element therefor. obscuring the operators View of it. Such a re- A cap 30, which is formed to slidably engage the 5 duction in key-diameter has the very desirable sides of the key-cup 22 with a tight fit, is a thin, effect of increasing the finger-space or well annular metal band withanarrowinturned brim between keys. or flange 3| and a plurality of downwardly ex- The key-caps have suitable ears or lugs artending ears or lugs 32. ranged to be clasped beneath the key-cup when After the annular ring 26, the character-disk the key is assemble-d. Such assembly may be 21 and the transparent disk 29 are assembled as 5 formed in a suitable press and sufficient pressure shown in Figure 3, the assembly is integrated by used to integrate the component parts into a slipping the cap 30 over the key-cup, pressing the tightly assembled unit. brim 3| downward to pinch the disk 29 tightly During the pendency of my application Serial against the edge of the cup, and bending the No, 698,063, filed November 15, 1933, (now Patent cars 32 inwardly beneath the key-cup. Rotation 55 of the protective disk 29 is prevented by the frictional engagement with the edge of the cup; the rotation of the character-disk 21 is likewise prevented by the frictional contact with the disk 29, the inner wall of the key-cup, and the surface of the annular ring 26,

The assembled key has a normally planar contact surface, as indicated in Figure 3. The brim 3| is not flush with the surface, but as it projects above it only slightly more than the thickness of the metal forming the brim, the key is much less punishing to the fingers of the operator than the usual high rim, glass topped, keys.

The contact surface of the key, being two-ply, flexible, and with an unsupported central area, yields slightly under the pressure of the operators finger as shown in Figure 5, cushioning the impact. In Figures 3 and 5, the character-disk 21 is shown of comparatively heavy stock, and the annular ring 26 is narrower, giving less direct support to said disk. With this type of annular ring, the disk 21 may preferably be made of Celluloid, treated fabric, or similar material.

In the form shown in Figure 2, the disk 21 may be of stiff paper, or similar material, as the annular ring 26 receives the greater force of the blow, and the central portion therefore concaves less than in the form shown in Figure 5.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. A key for use with a typewriter, comprising in combination, a circular-edge cup, said cup having provision for mounting on a key-lever, a circular composite key-disk including a character bearing disk united to a circular transparent disk, said transparent disk projecting beyond the border of the character-bearing disk, to form an annular brim portion of the composite disk, annular means within said cup underlying said character disk for supporting the same at its border only, said brim resting upon the circular edge of said cup, and a removable annular metal cap fitting on, and pinching said brim down upon the edge of, said cup to clamp the same against accidental rotation with respect to said cup.

2. A key for use with a typewriter, comprising the combination of a cup having provision for mounting on a key-lever, a flat-topped annular support within said cup and resting on the base thereof, a resilient character-bearing disk supported on said annular support within said cup, a resilient transparent protective element of diameter equal to the breadth of said cup resting on said character-disk and on the edge of said cup, and a metal band having an inturned brim arranged for clamping said protective element against the edge of said cup.

3. A key for use with a typewriter, comprising the combination of a cup having provision for mounting on a key-lever, a fiat-topped annular support within said cup and resting on the base thereof, a resilient character-bearing disk supported on said annular support within said cup, a resilient transparent protective element of diameter equal to the breadth of said cup resting on said character-disk and on the edge of said cup, and a metal band having an inturned brim arranged for clamping said protective element against the edge of said cup, the surface of said protective element remaining substantially planar.

4. A key for use with a typewriter, comprising in combination, a circular-edge cup, said cup having provision for mounting on a key-lever, a circular composite key-disk including a characterbearing disk united to a circular transparent disk,

said transparent disk projecting beyond the border of the character-bearing disk to form an annular brim portion of the composite disk, annular means within said cup underlying said character disk for supporting the same at its border 5 only, said brim resting upon the circular edge of said cup, and a removable annular metal cap fitting on, and pinching said brim down upon the edge of, said cup, to clamp the same against accidental rotation with respect to said cup, said composite disk being sufficiently flexible and sufiiciently unsupported at its character-bearing area, to flex when struck a staccato blow by the operators finger, thereby cushioning the key stroke, said cap resisting the tendency of the disk, when it is flexing, to pull off from the cup edge.

JESSE A. B. SMITH.

Images