US2036273A - Typewriting machine - Google Patents

Description

A ril 7, 1936. w. F. HELMQND TYPEWRITING MACHINE Filed Nov. 23, 1933 I NVENTOB: 7 m

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Patented Apr. 7, 1936 UNITED STATES PATENT OFFICE TYPEWRITING MACHINE William F. Helmond, West Hartford, Conn., as-

signor to Underwood Elliott Fisher Company, New York, N. Y.,' a corporation of Delaware Application November 23, 1933, Serial No. 699,314

8 Claims. (Cl. 197102) This invention relates to improvements in typewriting-machine keys, in which concaved character-disks are confined in metal cups, which surmount the stems of the key-levers. The disks may be of inflammable quality, such, for example, as celluloid, and may be protected against ignition by the key-cups and by annular metal caps which retain the character-disks.

According to the present improvements, the

1 concaved area of the key is considerably broadened, rendering it more agreeable to the touch of the finger, and presenting a working surface from which rises no ridge or other protuberance,

whereby punishment of the fingers is avoided.

The inturned flange of the fastening cap is itself concaved, and made flush with the concaved surface of the character-disk.

Heretofore a confining flange, formed upon an annular key-cap, has extended inwardly over the border of the character-disk, with-the result that the diameter across the key betweenthe edges of the cap-flange has been so reduced as to be objectionable, failing to afiord a sufficiently clear view of the character. Therefore one feature of the invention is to reduce the width of the inturned brim of the cap.

According to the present improvements, the molded character-disk has an enlarged area, to enable it to rest upon the upturned edge of the key-cup; the periphery of the character -disk being flush with the outer periphery of the cup. The inturned flange of the retaining cap bears down upon the brim or border-portion of the character-disk. Said brim rests upon the top edge of the key-cup. The cap holds the brim firmly down upon the edge of the cup. The area of the character-bearing surface of the key is much extended, while the width of the inturned flange of the cap is substantially lessened and -rendered inconspicuous, affording relief to the eyes of the operator.

In some cases, the entire diameter of every key may be somewhat reduced, thus enlarging the space or well down into which the operator must dip his finger, and the finger is therefore not liable to catch any adjoining key, at either front or back or at one side or-the other, which is a substantial advantage, especially where it is desired to operate the keyboard withoutlookirlg -15118 keys. 5

Another. featurezofithe:presentinvention con sistsLjin-inovel-vmeans for) loeating the characterdisk rotativelm This result is 'efiected by' splinin'g the dislr directly. ;to.: a-ztonguewhich projects u strum the key-lever stemswithimsthe'mupF-thecharacter-disk being molded with a slot in its bottom, and the flat tongue of the key-stem being fitted in said slot. This also cheaply and effectually prevents accidental rotation of the character-disk in operation. 5

Other features and advantages will hereinafter appear.

In the accompanying drawing,

Figure 1 is a perspective view of .the present improvements in preferred form. 10

Figure 2 is a cross-sectional elevation of the same.

Figures 3, 4 and 5 are perspectives of the cap, character-disk, and key-cup, with tongue or spline projecting up within the same, all as seen 15 at Figure 1.

Figure 6 is a. cross-section of a form of the invention in which the character-disk is made of sheet celluloid upon which is secured a layer of I transparent celluloid. 20

Figures 7 and 8 are perspectives of details of key seen at Figure 6.

Referring to Figures 1 to 5, each key-lever III is provided with stem ll, down upon which is forced a socket-portion l2 formed in the bottom 25 of a key-cup l3 having circular sides l4.

Within the cup is placed a molded disk l5 of celluloid, shellac or other hard wearing substance. Said disk includes a crown-portion having embedded therein a character IS; the top 30 surface of the crown being concaved as shown.

Projecting beyond the crown l5 of the character-disk is an integral horizontal flange or brim ll, which seats upon the top edge of the cup l4,

' and is flush with the sides of the cup, as seen at 35 Figure 2. This character-disk may be formed with a bottom recess l 8 below the brim ll, so that the body of the disk may nest or seat closely within the cup as seen at Figure 2; the edge of the cup fitting in said recess I8. 40

The character-disk is fastened down upon said cup-edge by means of an inturned flange IQ of an annular key-cap 20, having ears 2| to clasp under the bottom of the cup and hold the character-disk firmly down upon the edge of the cup. 45 The clasps of the key-cap are usually unben't before removing the character bearin'g member. Thewidth of the flange-His very-'slight and" thef character surface of the key maybe very 5mm;

as-senfatzFigures l -and 2;'thenarrow border [9 5 0 an'd'ihe broadlyconcaved finger-striking "surfacej-f beingi'desirable' to avoidtiiing the "eye" or The top ofxtheflange l 9 is concaved witlr thez-concaved surface of= the topof-the-keydisk 15, as seen at Figure 2, so that an unbroken concaved surface extends entirely across the key. The inturned flange [9 seats in a shallow annular recess 22 formed in the upper border of the keydisk; the bottom of the recess being .the top of the brim, and the circular inner side of the recess being the periphery of the crown 15 of the character-disk.

It will be observed that the overall diameter of the three-part key may be practically reduced, as compared with standard practice, without diminishing the width of the character-disk, or the size of the character l6 embedded therein. Such reduction in the overall dimension of every key would have the effect of enlarging the open area down into which the operators flnger is thrust in operating every key; so that it is not necessary to point the finger so accurately as heretofore, and likelihood of a bordering key being accidentally caught by the finger is greatly diminished.

Accurate location of the character-disk is secured and accidental displacement thereof rotatively is prevented, by means of a spline or tongue 23 which projects up from the top of the stem II. In other words, the stem is prolonged or extended up into the key-cup and flts in a diametrical character-locating recess 24 that is molded in the bottom of the character-disk I5. The latter may have a downwardly thickened middle portion 25, in which the recess 24 may be formed. Thus the character-disk I5 is located rotatively, and rotation of the same is prevented, without incurring the necessity of using additional parts. At Figure 6, a character 26 is printed upon the lower celluloid disk 21. The upper disk 28 is transparent celluloid, and the disks are joined together. The two-ply disk may be molded into concaved form as shown, before being applied to the key. The outside diameter of the disk is the same as that of the cup [3, and the brim IQ of the key-cap 20 may be the same as at Figure 2,

. to hold the key-disk firmly down upon the brim of the cup; the lower ply of the celluloid disk being extended as at 29 to overlie said brim, while the upper disk 28 is of less diameter and extends to the inner edge of the key-cap brim It as at Figure 6. The thickness of the flange I8 is the same as that of the upper celluloid disk 28, so that this key also presents a smooth unbroken concavity for the entire width of the key. No means are shown for mechanically locating the character-disk 21 in the correct rotative position, but disk 21 may be made slightly over-size, and may be forced down within the key-cap 20, the latter being firmly gripped by the clasps 2|, so that rotation of the character-disk during use is prevented.

This invention is in the nature of an improvement upon the application of Jesse A. B. Smith, Serial No. 698,063, flied November 15, 1933. '3 i 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. In a typewriting machine, the combination of a key-cup, a character-disk of equal breadth with the cup and resting upon the brim of the cup, and a key-cap holding said disk upon the brim, the'key-cap having an inturned holding flange of a width about equal to the thickness of the wall of the key-cup, affording a broadened exposure of the surface of the key, said character-disk having an annular border-recess into the character-disk to the cup.

which said flange is sunken to be flush with said key-surface.

2. In a typewriting machine, the combination of a key-cup, a character-disk of equal breadth with the cup and resting upon the brim of the cup, and a key-cap holding said disk upon the brim, the key-cap having an inturned holding flange of a width about equal to the thickness of the wall of the key-cup, affording a broadened exposure of the surface of the key, said char-' acter-disk being concaved, and said flange being flush with the top of the disk and correspondingly concaved; said disk being molded and having a character sunken therein,

3. In a typewriting machine, the combination of a-key-cup, a composite character-disk of equal breadth with the cup and resting upon the brim of the cup, and a key-cap holding said disk upon the brim, the key-cap having an inturned holding flange of a width about equal to the thickness of the wall of the key-cup, afiording a broad- *ened exposure of the surface of the key, said of a key-cup, a character-disk of equal breadth with the cup and resting upon the brim of the cup, and a key-cap holding said disk upon the brim, the key-cap having an inturned holding flange of a width about equal to the thickness of the wall of the key-cup, affording a broadened exposure of the surface of the key, said character-disk being concaved, and said flange being flush with the top of the disk and correspondingly concaved; said clip having a bottom socket, said character-disk being molded with a bottom slot, and a key-bearing stem inserted in said socket and extending up into said slot to locate the character-disk rotatively.

5. In a typewriting machine, the combination of a key-cup, a character-disk of equal breadth with the cup and resting upon the brim of the cup, and a key-cap holding said disk upon the brim, the key-cap having an inturned holding flange of a width about equal to the thickness of the wall of the key-cup, aifording a broadened exposure of the surface of the key, said character-disk being concaved, and said flange being flush with the top of the disk and correspondingly concaved; said cup having a bottom socket, said character-disk being molded with a bottom slot, and a key-bearing stem inserted in said socket and extending up into said slot to locate the character-disk rotatively, said molded character-disk being formed with a thickened portion on its under side in which said slot is formed.

6. In a typewriting machine the combination of a key-cup having an edge, a characterdisk having a brim resting upon the edge of the cup, and a cap detachably secured upon said cup 1 and holding said brim down upon said cup, said character-disk having a crown flush with the top of said cap, said cup having a bottom socket, said character-disk being molded with a bottom slot,

and a key-bearing stem upon which said cup is 1 mounted, said stem projecting upwardly into the slot of said character-bearing disk to locate the same rotatively, and said cap having tongues which clasp under the bottom of said cup,

to clip a 7. A three-piece typewriter-key, having (1) a finger-disk molded of hard material and provided with a character thereon, and formed with a brim-portion, (2) a cup having an edge upon which the finger-disk is mounted by means of the brim-portion thereon; the diameter of the A brim-portion being substantially 'equal to the dif ameter of the cup; said character-disk having a character-bearing crown-portion rising from said brim-portion; and (3) a cap fitting over said brim-portion and flush with the top of the fingerdisk, and enclosing the cup and clipping the character-disk to the cup; a key-stem upon which said cup ismounted, and means independent of said cup and said cap and elfective to locate the finger-disk rotatively, including a spline rising from said key-stem, and a grooved'portion provided 0n the under portion of said finger-disk to enable said spline to control the rotative position of the character-disk.

8. A molded character-disk for a typewriter key, said disk molded with a brim for clipping it to a support or base, and also molded with a character-bearing crown to be flush with a securing cap, and also molded with a slot in its bot-' tom in line with the center of its character, for

co-operation with a key-stem spline to locate the disk rotatively upon the support.

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