US1456741A - Typewriter - Google Patents

Description

May 29, 1923, 1,456,741

' P. RICHTER TYPEWRITER Filed July 5, 1922 A :3 Sheets-Sheet 1 K- il PA uz. Pfc/155e PHE 5' May 29, 1923. Y 1,456,741 P. RICHTERr TYPEWRITER Filed July 5, 1922 3 Sheets-Sheet 2 l IIIV. 451177171' PA UL P/CHTE May 29, 1923. ,f 1,456,741

P. RICHTER TYPEWRITER Filed July 5, 1922 s sheets-sheet 3 7 PAUL P/CHTE Patented May 29, 19,23.

^ UNITED STATES 'PAUL'I RICHTER, or DALY CITY, CALIFORNIA.

TYPEWBITEB.

Application led July 5, 1922'. Y SetiialV No. 572,943.

To all whom t may concern: l

Be it known that I, PAUL RICHTER, a citizen of the United States, residing at` Daly City, county of San Mateo, and State of California, have invented new and useful Improvements in Typewriters, lof which the following is a specification.

This invention relates to a. typewriter and especially to the mechanism whereby movement is transmitted to the type-bars.

The object of the present invention is to generally improve and simplify devices of the character described; to provide a typebar action whereby a short, practically uniform, touch is effected and whereby a sharp blow may be obtained; to prevent smudging of the print by permitting a slight rebound action of the type-bar with relation to the cylinder or platen, and by positively preventing contact of the type with the platen after the blow has been struck and rebound action has taken place; to reduce the stroke of the key action to a minimum, and in general to provide a compact arrangement and simple accessible assembly of the mechanism.

Other objects willhereinafter appear.

One form which my invention may assume is exemplified in the following description and illustrated in the accompanying drawings, in which- Fig. 1 is a central, vertical, longitudinal section of the typewriter. f

Fig. 2 is a plan view Apartially in section and partly broken away, and the type-bars and keys being entirely removed.

Fig. 3 is an end 'view of Fig. 4.

Fig. 4 is a detailed 'view in side elevation showing the key levers, the front cone and the pivot bracket by which they are supported. i

Fig. 5 is a perspective view of the typewriter partly in section and partly broken away, one key lever and type-bar, with intermediate connections, being shown.

Referring to the drawings in detail, and particularly to Fig. 1, A indicates the main frame of the typewriter, 2 the key levers, 3 the keys, 4 the brackets in which the keyl levers are ivotally mounted, as at 5, 6 a sub-lever pivotally supported on a cross rod 7, 8 a cam lever pivotally supported as at 9 in a cam lever bracket 10, 11 the type bar, 12 the platen, and 13 .the segment in which the type bars are pivotally mounted as at 14.

The main novelty of the present invention embodies: first, the connection formed between the key lever 2,the sub-lever' and the cam lever 8, and secondly, a cam action formed between the type-bar and the cam lever.

By referring to Fig. l,.it will be noted that the inner end of the sub-lever is shoeshaped, as at 15, and that it straddles the free end of the key lever. Further, that the sub-lever and key lever are normally held in a' horizontal position by a stop 16 formed in the. upper part 'of the front comb 17, and that said position is maintained by means of a spring 18. Again, it will be seen that the connection formed between the sub-lever and the camv lever is obtained by a wire link 19 and that depression of key 3 will thereforel be transmitted to depress the key lever and the sub-lever as shown by dotted lines at 22L and 63,-. respectively, and that the lmovement of these parts is transmitted to the wire link 1 9 to depress the cam lever as indicated by dotted lines at 8a. This movement of the cam lever is in turn transmitted through a C-shaped cam, generally yindicated at B, which is formed on the cam lever, to a second cam generally vindicated at D, which is formed on the inner end of the type bar. The cam member B, formed on the lever 8, is provided with an upper contact point 2O and a lower Contact point 21. The cam member D is rovided with an upper cam surface 22 an a lower Cam surface 23. The formation of the upper cam sur-V face 22 is of considerable importa-nce and it consists of an inner section or face havin a constant radius, as illustrated at 24, whio extends from thepoint 25 to the point 26. The remaining surface of the cam 22 is also curved, but the radius of the curve is of constantly increasing length. The distance of this curved surface extends from the Joint 26 to the outer end of the cam 22, whic terminates in a finger 27. The exact curvature of the lower cam face 23 is also of im ortance as it is so designed that it will follow the curve or arc through which the point 21 of the cam B passes when moved from the full line position to the dotted line position shown at 8a. The cam member 8 is normally held in the raised full line position shown by means of a spring 30, and thisspring action also assists the spring 18 torestore the sublever and the key lever 2 .to normal position. The springs also serve the function of returning the type bar 11 to horizontal position, as shown in Fig. 1, as upward movement of the cam lever causes the point 2l thereof to engige the lower side of the linger 27 and ereb impart return movement to the type bar; t e speed of the return movement being only limited by the return action of the 'cam lever 8 as the point 21 thereon remains in constant engagement with the upper cam surface 22 of the type bar.

For the purpose of maintaining perfect alignment between the cam members B and D, a back comb or plate 32 is employed. This plate is slotted, as at 33, and these slots form guides for the cam members B and D, the cam member D being further guided by the slots formed in the segment 13.

The type bars when in normal position engage a back stop or cushion bar 3i and when in raised or striking position engage the platen 12, being guided with relation to the platen to assume a certain striking posi- `tion by means of a type bar guide generally indicated at E.

In the description so far rendered, a single key level', type bar and actuating mechanism has been described, but it should be understood that the typewriter is provided with the usual number of key levers and type bars, and that they are all connected in the manner shown in Fig. 1, the type bars employed being pivotally supported in the segment 13 as this is slotted to receive the same, as shown in Fig. 5. The key levers are individually supported by bracket plates 4, and they are all guided by the slotted front comb 16. The cam levers 8 are all pivotally supported in the cam lever bracket 10, which is slotted Jfor their reception, and the f ront ends of the cam levers, or the cam portion indicated at B, are guided by means of the back comb indicated at 32. The platen may be supported in the usual manner and is for this reason only diagrammatically illustrated. Other parts of the mechanism, such as the spacer, release mechanism, back spacer, etc., are not shown as they form no material part of the present invention; the whole invention being limited to the cam members B and D andthe connection formed between the key lever and the cam lever 8.

As previously stated one of the important features of the present invention is the reduction of the movement of the keys to a minimum. In actual practice the depression or movement of the keys does not exceed three-eighths of an inch as indicated by the dotted line position in Fig. 1, such short key movement being obtained by the use of the sub-lever 6, that is the distance between the pivot 5 of each key and the front end of the sub-lever 6 is so short that comparatively limited movement of the key is required. This limited movement is however enlarged by extending the opposite end of the sublever any desired distance to transmit movement through link 19 to cam lever 8, thus,

by moving the pivotal point 5 inwardly or outwardly, any desired depression of the key 3 and the lever actuated thereby may be obtained. The second important feature is the cam mechanism indicated by the reference characters B and D. This mechanism is of importance as it permits the transmission of a sharp blow and positively prevents a smudging action by permitting rebound of the type bar, that is during depression of a certain key, particularly when a quick movement is transmitted thereto, depression o't' cam lever 8 also takes place. This movement of the cam lever causes the point 2() to engage the upper cam surface 22 of the cam member l) and as the outer end of this cam surface has a curve of constantly increasing radius, it can be seen that engagement of the point 20 therewith will impart a swinging movement to the type bar about the pivot 14, and that this movement will be so rapid that a sharp blow will result. The point 2O continues to exert pressure on the cam surface 22 until the point 26 is reached, but as' the curve of the cam surface here assumes a shape of constant radius, it can be seen that pressure of theI point 20 thereon will have no effect. The type bar will therefore continue to swing upwardly and strike its blow and it will then rebound from the platen after the blow has been struck, the rebound being permitted, due to the constant radius surface formed between the points 25 and 26. Therefore even though continued pressure should be applied to the key 3, after rebound action has taken place, return movement of the type bar with relation to the platen would not take place as the point 20 would merely engage a surface of constant radius, which has no lever action, whereby movement could be imparted to the type bar, and it is for this reason that rebound movement can' take place, and it is also for this reason that the type bar is prevented from again engaging the platen even though continued pressure should be applied to the key. If it should be desired to repeat the action of the type bar, for instance if double LL should be struck, it would be necessary to release the key 3 and again strike the same.

To insure-return of the type bar from the vertical dotted line position shown at 40, which is assumed after rebound action has taken place, finger 27 and point 21 are employed, that is the point 21 of the cam engages the lower side of the linger 2 when key 3 is released and as the cam lever is returned to normal position by the springs 30 and 18, it can be seen that engagement of the member 21 with the lower side of the linger 2T will impart a reverse swinging movement to the type bar and therefore rapidly return the same. action is in this manner obtained, a sharp ment of the action and woul blow is produced, smudging is prevented due to the rebound movement permitted, and a comparatively short movement of the keys 3 is obtained due to the use of the sub-lever 6 and the cam members B and D actuated thereby. The entire key and type bar action canbe assembled in an exceedingly compact unit and as all parts are positively guided, dependable and sensitive action can be relied upon. Lost motion, due to Wear, would in this instance be of comparatively little importance as such Wear would almost entirely take place at the pivotal points indicated at 5, 7 9 and 14. Such wear 4would not affect the eneral movefor this reason be of no importance.

IVhile certain features of the present invention are more or less specifically illustrated, I wish it understood that various changes in form and proportion may be resorted to Within the scope of the appended 'claims, similarly that the materials and finish of the several parts employed may be such as the experience and judgment of the manufacturer may dictate or various uses may demand. Y

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. In a typewriting machine-of the character descrlbed, a type bar pivoted at one end, an upper cam surface formed on the bar adjacent the pivot, the inner end of said cam surface having a curvature of constant radius and the remaining portion thereof having a curvature of constantly increasing radius` a lever engageable with the cam surface to impart a swinging movement to the type bar, a key lever, and means for transmitting movement from the key lever to said last named lever.

2. In a typewriting machine of the character described, a type bar pivoted at one l end, an upper cam surface fornied on the bar adjacent the pivot, the inner end of said cam surface having a curvature of constant engaging the finger to return the type bar.

to inoperative position.

3. In a machine of the character described the combination withthe type bar, of a cam -member formed on the inner end thereof, said cam presenting an upper cam surface, .the inner portion of the cam surface being a curve of constant radius and the remaining portion of the cam surface being acurve of constantly increasing radius, a pivotal support for the type bar extending through the' cam member, and a cam lever engageable with the cam surface to impart movement to the type bar about its pivot.

4. In a machine of the character described the combination with the type bar, of a cam member formed on the inner end thereof, said cam presenting an upper cam surface, the inner portion of thecam surface being a curve of constant radius and the remaining portion of the cam surface being a curve of constantly increasing radius, a lpivotal support for the type bar extending through the cam member, a cam lever engageable with the cam surface to im art movement to the type ebar about its plvot, a finger formed on the cam member below the cam surface of constantly increasing radius, and means on the cam lever adapted to engage said finger to impart movement to the type bar in one direction.

PAUL RICHTER.

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