US2304357A - Typewriting machine - Google Patents

Description

Dec. 8, 1942. w. F. HELMOND TYPEWRITING MACHINE Original Filed Sept. 14, 1937 3 Sheets-Sheet 1 a MN INVENTOR W/LL/AM E HELMOND BY A? ATTORNEY w. F. HELMOND 2,304,357 7 Dec. 8, 1942.

IYPEWRITING MACHINE 5 Sheets-Sheet 2 Original Filed Sept. 14, 1957 INVENTOR Mu MM E HELMOND ATTORNEY W. F; HELMOND TYPEWRITING MACHINE Dec. 8, 1942.

Qriginal Filed Sept. 14, 1937 3 Sheets Sheet INVENTOR v W/LL/AM E HELMOND BY K I ATTORNEY Patented Dec. 8, 1942 TYPEWRITING MACHINE William F. Helmond, Clinton, Conn, assignor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Original application September 14, 1937, Serial No. 163,739. Divided and this application June 29, 1940, Serial No. 343,112

7 Claims.

This invention relates to typewriting machines, and, with respect to certain more specific features thereof, to case shifting mechanism and key controls therefor. This application is a division of my application Serial No. 163,739, filed September 14, 1937, now Patent No. 2,226,931, issued December 31, 1940.

One object of the invention is to provide a simple, cheaply manufactured, smoothly operating key-operable case shift mechanism.

It is another object of the invention to provide, in association with two keys that are operable to case-shift a body, a simple, reliably op-.

erating device which will normally detain one of the keys upon being depressed, and which device is rendered ineffective by the depression of the other key.

A further object of the invention is to provide simple and reliable operating spring-pressed means to detain widely separated lock-keys upon being operated to case-shift a body, the means being adapted to be rendered ineffective by operating other widely separated keys so as to free the lock-keys to allow restoration of the caseshift body. These last-mentioned keys are also operable to case-shift said body while the lockkeys are in normal position; In any event they will return immediately to normal position upon being released.

Another object of the invention is to provide a key operable case-shift mechanism having an extremely light and smooth key-touch.

Further objects and advantages of the invention will readily become apparent as the description of the invention proceeds.

In the embodiment of the invention shown, a case-shift lock-key is operable to case-shift a body and is automatically detained in operated position by a spring-pressed lock-pawl that is pivotally mounted on the lock-key and adapted to engage a machine frame shoulder. Another shift-key is also operable to case-shift said body but does not carry a lock-pawl and, therefore, reassumes its normal position immediately after being released. The latter shift-key may also be operated to release the lock-pawl on the caseshift lock-key ,and a portion thereof is for this purpose engageable with the lock-pawl to throw it to ineffective position. There is a case-shift key and a case-shift lock-key at each lateral end of the keyboard and these keys are respectively interconnected for operation in unison. Preferably each of the case-shift lock-keys carrie a lock-pawl and each of the interconnected case- Til pawls to move it to ineffective position. It follows, therefore, that the depression of either caseshift key will release both latches on the caseshift lockkeys to allow their return to normal position.

In the accompanying drawings:

Figure 1 is a transverse sectional view through a machine embodying the invention, taken on the front and back radial plane and showing the type bar segment in normal upper position for typing in lower-case type.

Figure 2 is a perspective view of the entire caseshift mechanism in normal position, with the type bar segment in normal raised position for typing in lower-case type.

Figure 3 is a fragmentary perspective view similar to Figure 2, showing the case-shift lock-keys depressed and held by lock-pawls to detain the case-shift body for typing in upper-case.

Figure 4 is a view similar to Figures 2 and 3, showing the case-shift levers in operated position and the lock-pawls on the case-shift lockkeys moved to ineifective position by the caseshift levers.

The type-action illustrated in the drawings is similar to that shown and described in my Patent No. 2,072,878, dated March 9, 1937. The type-action includes a system of key-levers l2, fulcrumed adjacent the back of the machine, the key-levers being flexibly joined by links I 3 to a series of sub levers l4 pivoted on a fulcrum-rod I5, carried in a cross-bar I 6 mounted on the side plates l1 comprising the frame of the machine. The sub-levers l4 actuate a system of type-bars l8 by means of pull-rods l9 flexibly joining the free end of each sub-lever M to a drive arm 20 of the type-bar [8. The series of type-bars I8 are pivotally mounted in a segment 2| for swinging toward a common printing point on a platen 22, the latter being guided for letter-space movement, by a platen carriage 23 riding in a trackway 24 extending between the side plates H.

The segment 21, together with a segmentframe 25 to which it is secured, constitutes a case-shiftable body. The segment-frame 25 has depending members or arms 26 wherein a rockshaft 28 is journa'led in bearings 21, the shaft 28 extending laterally to the side plates l! of the machine and carrying at each end an antifriction roller 29 that is guided between vertical guide-faces 30 in the side-plates H.

The segment-frame 25 has at each lateral upper end a raceway 36 flanked by a companion raceway on the frame, not shown, and balls 33 shift keys in 'engageable with one of said lockcooperate with these companion raceways to guide the segment-frame 25 at its upper region.

As will be described hereinafter in detail, the rock-shaft 28 accomplishes several functions, namely, that of coordinating the action of the two case-shift lock-key levers 62 located at opposite sides of the machine, and enforcing equal movement of both ends'of the segment-frame 25.

At each extremity, the rockable shaft 28 has associated therewith an articulated leveragetrain 55, comprising a first arm 56 affixed to the shaft 26, and a second arm 51 fulcrumed at 58 on the main frame, and articulated to the first arm 56, so as to constitutea toggle joint. Fulcrum 58 is disposed on a line defining the path of travel of the segment-frame 25 in case-shifting and below same, so that when the arms 56 and are aligned, one with the other, the segment 2| and associated type-bars i8 are maintained in raised position thereby for lower-case typing. As arm 51 is caused to swing, the togglej'oint or leverage-train 55 is unlocked and folded .to lower the segment assembly to upper-case typing position.

Each arm 571 forms part of a bell-crank also including a drive arm 52, each of which drive arms is fiexiblyjoined bya link-66 to an arm 6| of a shift-'lock'lever 62. Springs 59, attached :to the lock-levers 62, urge the latter to normal position'so that said toggle joints 55 are normally straight and hold said segment 2| and segment-frame 25 in lower-case typing position,

as seenin Figures 1 and 2. Each shift-lock lever 62 is fulorumed on the sub-lever fulcrum-rod l5 and extends forwardly of the machine, terminating in a shift-lock key 63. Each shift-lock lever 62 has associated therewith a shift-lever 64, also fulcrumed on rod l5 and carrying a shift-key 65 at its free end. Shift-lever 64 includes a lug 66 extending therefrom to overlie the lever 62 so that upon depressing the shiftlever 64, the lock-lever will move therewith,

although the shift-lock lever 62 may be actuated independently of the shift-lever 64. The return spring 59 is anchored on the machine, its end being joined to a depending member of the lockilever arm 6! whereby to urge the toggles 55 to aligned condition so that same hold the segment raised, the toggles 55 being stopped at aligned setting by the engagement of the lock-lever 62 with aguide-plate T4 or other member of the machine.

Due to the normally. straightened condition of the toggles, the initial leverage of the keys '63, 65 to case-shift the segment frame 25 is ex tremelygreat, consequently, touch of these keys .is extremely light andpleasing. The segment- .frame 25 is shown in Figures 3 and 4 as having been shifted respectively by the depression of the case-shift lock-key and the case-shift key. One or more stops, not shown, are provided to limit the case-shift movement of the segmentframe.

It will be noted from the foregoing that the rockable shaft 26, by operatively connecting the arms 56, functions to coordinate the actions of both of the toggles 55 whereby lowering or raising power thereof is imparted equally to both extremities of segment 2|, Figure 2. Since each toggle 55 is operably associated with a corresponding shift-lock lever 62, the actions of the respective levers 62 are also coordinated. The rockable shaft 26, connecting the two arms 56 of'the toggles 55 together, is rotatably carried in the segment-frame 25, at a relatively high elevation in the machine, thereby affordingadequate space underneath for mechanisms such as the rearwardly extending key-levers.

A shift-lock 61 is provided to lock lever 62 down, the lock 61 being so associated with the respective shift- levers 62, 64, that when both levers move together, as by depressing lever 64, the lock is ineffective, and inversely, as the shiftlock lever 62 moves independently of the shiftlever 64, the lock 61 is allowed to engage. Lock 6'! comprises a lock pawl 66 presenting a bellcrank pivotally mounted on the lock-lever 62 and urged by a spring 69 to swing into locking engagement with a detent-shoulder 16, but normally prevented from so doing by the engagement of a lateral lug H of pawl 68, with a pad 12 on the shift-lever 64.

Figure 3 illustrates the operation of the mechanism in locking the segment down by depressing the lock-lever 62, the lock pawl 68 having been allowed to swing into engagement with the detent 16 by the tendency of the lug H to'move away gaging the lateral lug H, swings the-pawl 68 free of the detent 16, the pawl releasing at the instant thelug 66 reaches the depressed locklever 62. The shift-lever 64 thus assumes the power of the return spring 56, the latter tending to raise the segment 2|, Figure 5. Shift-lever 64 is now permitted to rise, being manually controlled, and the segment 2! returns to its normal raised position.

A particular advantage of the novel case-shift lock 6! is that both the shift-lock key 63 and the shift-key 65 are at a constant elevation at the time the function of either is required. As is usual in case-shift mechanisms, the shift-lock key is locked down during the interval atwhich the segment is locked down for upper-case printing, but, in such machines the shift-key is also lowered. In the present invention the shift-key 65 remains at normal position although the shiftlock key 63 be depressed and the operator may therefore accustom herself to finding the shiftkey 65 at the same elevation at all times. Furthermore, the work of releasing the pawl 68 from its detent i6 is minimized since the releasing is effected during the entire down-stroke of the shift-lever 64. This improved operation makes for an appreciably light touch and smooth ac-. tion of theshift-lever 64 in its unlocking function, the same acting without jar, by assuming the load. of-the segment mass, effective by the return spring 59, at the instant of release .of lock 61. ,1

The respective actions of each shift-lever 64 are coordinated by a rockable bail l5 'trunnioned on brackets 16 adjustably aflixed to the guideplate 14 by screws Ti disposed-in slots therein. The rockable bail 15, extending laterally. of the machine, includes a forked arm '58 at each end thereof which engages a pin 79 carriedon a member 86- of the shift-lever 64. It will be noted that the detent l6, co-operating with the lock 61 forms part of the bracket 16,-so that both the detent and the journal of the bail 15 are adjustable simultaneously. In the event that lowering of detent is required in regulating the shift mechanism, the lower locked position of lever 62 necessitates a greater drop for shiftlever 64 to release the lock 61, which increase is accommodated by lowering the bracket 16.

The work of the return springs 59, in restoring the type-bar segment 2| to normally raised position in co-operation with the toggles 55, is supplemented by balancing springs 82 which have the effect of resiliently sustaining the segment 2 I. Springs 82 are anchored at their upper ends to a fixed portion of the machine and are secured to studs 83 projecting from the segmentframe 25, Figures 1 and 2. The balance springs 82 may be so tensioned as to yieldably sustain the entire mass of the type-bar basket, the weight of which is supported by the segmentframe 25, the effect being to substantially reduce the effort required to move the segment in case-shifting.

It will be noted that at the depression of either shift-lock lever 62 relatively to its companion shift-lever 64, the other shift-lock lever 62 is also depressed relatively to its companion shift-lever 64, since both of said levers 62 are operatively connected by means of the crossshaft 28. Hence both of the locking pawls 61 are caused to move to effective position under their detents 10, as in Figure 3, at the depression of either shift-lock lever 62. The depression of either shift-lever 64 for the purpose of releasing the companion locking pawl 61 also serves, by means of the cross-shaft 15, to depress the other shift-lever 64 thereby to release also the locking pawl 61 associated with the latter. It is to be understood that one of the lock pawls may be eliminated, if desired.

What is claimed is:

1. In a case-shift mechanism for typewriting machines, two widely spaced case-shift keys, a case-shift lock-key operatable independently of said two case-shift keys, a lock-member pivoted on said lock-key, detent means adapted to be engaged by said lock-member to detain said lockkey upon operation, means for influencing said lock-member to engage said detent means, an interconnection between the said two case-shift keys, and means to render said lock-member free from said detent means by the operation of either of said two case-shift keys.

2. In a case-shift mechanism for typewriting machines, two widely spaced case-shift keys, a case-shift lock-key operatable independently of said two case-shift keys, a lock-member movable on said look-key, detent means adapted to be engaged by said lock-member to detain said lockkey upon operation, means for influencing said lock-member to engage said detent means, a connecting bail between the said two case-shift keys, and means to render said lock-member free of said detent means by the operation of either of said two case-shift keys.

3. In a typewriter having a case-shiftable body, a case-shift lock-key having an operative connection for case-shifting said body, two widely spaced case-shift keys, a lock-member movably mounted on said lock-key, a detent adapted to be engaged by said lock-member to detain said lockkey upon operation, means influencing said lockmember to engage said detent, an operative connection between the said two case-shift keys, means to render said lock-member free of said detent by the operation of either of said two caseshift keys, and means providing for operation of said case-shift lock-key by said case-shift keys but rendering said case-shift lock-key operable independently of said case-shift keys.

4. In a case-shift mechanism for typewriting machines, two widely spaced case-shift keys, a

case-shift lock-key adjacent to each one of said case-shift keys, means connecting the lock-keys to move together, means connecting the caseshiit keys to move together, a lock-member movably mounted on at least one of said lock-keys, detent means adapted to be engaged by said lockmember to detain the lock-keys upon operation, means influencing said lock-member to engage said detent means, and means for forcibly freeing said lock-member from said detent means by the operation of said case-shift keys.

5. In a case-shift mechanism for typewriting machines, in combination, a shift-lever, a locklever, substantially in juxtaposition to said shiftlever, one of said levers having a projection providing for the operation of said lock-lever by said shift-lever but rendering the lock-lever operatable independently of said shift-lever, and lock means for releasably detaining the lock-lever upon operation, comprising a pivoted pawl having a projection underlying said shift-lever, a detent engageable by said pawl, and spring means associated with said pawl and urging it toward said detent, the pawl being normally held from said detent by said shift-lever and being urged by said spring means to engage said detent upon depression of said lock-lever.

6. In a case-shift mechanism for typewriting machines, two spaced case-shift lock-keys interconnected to move in unison, lock-means for releasably detaining said lock-keys upon operation, detent-means engageable by said lock-means, spring-meansurging said lock-means to engage said detent-means, and a pair of spaced caseshift keys interconnected to move in unison and operatively connected with said lock-means so that operation of either of said case-shift keys renders the lock-means ineffective.

7. In a typewriter having a case-shiftable body, toggle-means operable to case-shift said body comprising widely separated toggle-linkages interconnected for operation in unison, a caseshift lock-key connected to each said toggle-linkages, a lock-member carried by each of said lockkeys, detents engageable by said lock-members in the operated position of said toggle-means, means resiliently urging said lock-members to engage said detents, and other case-shift keys interconnected for operation in unison and having each'an operative connection with one of the lock-members, said operative connections being adapted to render said lock-members released upon operation of the last said keys.

WILLIAM F. HELMOND.

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