US2521478A - Power-actuated typewriter - Google Patents

Description

Sept. 5, 1950 s. PETI'F POWER-ACTUATED TYPEWRITER 2 Sheets-Sheet 1 Filed April 28, 1948 ATTORNEYS? Sept. 5, 1950 v s. B. PETlT 2,52

POWER-IAC'IUATED TYPEWRITER Filed Apxfil 28, 1948 Sheets-Sheet 2 IN I "EN TOR.

5/50/7672 5. Pei/7' B Y M W? Qh A T Tom 5 Y5 Patented Sept. 5, 1950 omreo STATES PATENT orrice Stephen tetit fiayonne l l. 3., assignor to Heaven Letters me, New York, N. Y., a corporation of new York Assess-me April 28, 1948, Serial Ncrzsflsc r earns; (01. new

1 This invention relates to power actuated.- typewriters, and in some aspects has particularly to do With that kind of power typewriter in Whicha record tape having perforation-s selects the type bars to be actuated by suitable operating levers connected. with the individual typ'e bars to be selectively displaced from their normal; idle positions into the path of a' power operated actuator common to all the operating levers;

Tape controlled machines or the kind referred to are commonly empio'yed' for the typing of circular letters. The object of duplicating the letters by typing rather than by multigr'aphin'g, m'ime'ographing, heetographing or printing is to produce a letter having the sam appearance as one composed and typed for the sole benefit of the addressee. While the body of the letter can be automatically typed again and again from the perforated record, it is desirable that the address be filled in to match the typing of the body of the letter in type, ribbon color, ribbon Wear and evenness of touch. this can be best accomplished by manually selecting, but power operating, the type bars when typing the address. There have been prior proposals for providing machines capable'of operating upon this desirable principle, but these proposals have proved abortive for reasons which will be pointed out.

It has been proposed (see Guthrie Patent 1,206,534) to connect the operating'levers to their respective type bars through. the usual key levers of a standard typewriter keyboard, and to provide operating lever" displacing means operated manually by the keys. iJhus, the manual opera tion of a'key would be caused to displace the asso ciated operating lever into position to be actuated by'the power actuator. A key stroke begun manu= ally would be completed under power'operation to match the typing in the body of the letter.

A mechanism such as thatpropo'sed Would'have been inoperative. There can'be no timed rela-' tion between the operation of the actuator and the manual operation of a key, The manual displacement of an operating lever may occur at that-point in an actuator cycle when it is just too late for the actuator to move the operating lever on the current actuator strokei If then, the key is not held down-by the operator for at least-a full actuator cycle,no type bar operation will result from the operation of the key.

If, on the other hand, the operating lever dis placement occursjust a'trifie' earlier than in the previous example, then two operations of the type bar will resultfor a single actuation of the ey unless the key is released early enough to 2 permit restoration of the operating lever to its normal, ine'iiective position before a full cycle of the actuator has been completed. With this kind of mechanism it is impossible for the typist to operate the; machine successfully, for in some instances the operating lever must be held dis placed for less than one actuator cycle, while in" other instances it must beheld displaced for more than one actuator cycle. Of. course, the typistnever knows Whether along depression or a short depression of a key is necessary, and even if he did, itwvou-ld' be quite impossible to time the operation as required.

According to a later proposal (see Evans Patent 1,769,624); the keys and key levers were" to be arranged to be used merely as trippers', and the power supplied by the" actuator was to be transmitted through the operating levers to the" type bars independently of the key levers. Tape control led" pins at the rear of the operating levers f-c'r' causing the levers to be selectively displaced by power operated displacing mechanism were tobeduplicated at the forward-ends of the operating levers for keyboard" control; and the" power operated displacing mechanism was to be duplicatedalso? With' the proposed-Evans'rria'chine there would be no danger of failing to produce a type bar actuation" in response to a key opei'atiohl but there would be great likelihood of producing fe peated operation response" to a single key operation if the key were held down for just a little longer than the period of an actuator cycle; Atthe' best; much time" and material wouldlbe Wasted in specially traininga typist iii the use of the machine. The Evans" machine has not gone intb comirierciaruse.

In accordance with the present invention the principle or power operating the typebars from the operating levers independently of the key levers is' adhered to; but the mechanisirifisfim preve'a in such away as to assure" that there will be a ower cperatich'or the selec' 't' no 'niatt'e'r how rapidly an op been returnedto noriiial position will be but one-operation of the 'selc no matter how slowly an operate'd' key beeirreturnedto normal p0 1 n. p U I To end, a' spring impel disp lacir'iglei/er is provided eorijuuctionxv h ear: I plating lever, and each displacing lever" is" normally h in. its retracted or ineffective est r; butwith its spring under st ress,- b y a detest; I Each deiea. tran e 2 o era e brack sh key.

- andwhen tripped permits the associated displacing lever to act to displace the associated operating lever into the path of the actuator.

It is a salient feature of the invention that the movement of the operating lever by the actuator is utilized to retract the displacing lever and to store in its impelling spring the power which is to be used in the next displacing operation of that lever. This mode of operation has two important advantages. One of them is that the force which is utilized for displacing the operating lever is supplied by the power actuator. The other is that the displacing lever remains displaced until it is restored by the associated operating lever. There is no possibility, therefore, of a failure of operation of the desired type bar, no matter how quickly the operated key may have been returned to normal position.

It is a further feature that the operative connection between a key and a detent is temporarily broken as soon as the associated displacing lever has been tripped. Thus the detent is freed at once for restoration to detaining position and is not retarded by any delay of the typist in releasing the operated key. There is no possibility, therefore, of producing repeated type bar operation in response to a single key actuation.

The invention has important utility, whether or not provision for tape control is embodied in the machine.

Other objects and advantages will hereinafter appear.

In the drawing forming part of this specification Fig. l is a fragmentary view in side elevation of an illustrative, automatic typewriter embody- 1 ing features of the present invention;

Fig. 2 is a fragmentary, detail view showing the lower portion of one of the key stems;

Fig. 3 is a fragmentary view showing the illustrative mechanism with the displacing lever tripped by the depression of the key and displaced with the operating lever shifted forward into position to be engaged and operated b an impending downward stroke of the actuator; and

Fig. 4 is a view of substantially the mechanism shown in Fig. 3 with the key returned to normal and the other parts shown in the positions occupied by them at the conclusion of an effective downward stroke of the actuator.

The illustrative machine comprises all of the conventional mechanism of a standard typewriter with the exception that levers I, which would normally extend forward to the keyboard and constitute the key levers of the machine are cut short and connected through slotted, adjustable links 2 with operating levers 3. The usual springs IA urge the levers l to their normal positions.

The levers l are connected through slotted bell cranks 4 with the respective type bars 5 of the typewriter. The type bars 5 are mounted upon a pivot wire 6 and are guided in the slots of a type segment of the Underwood type to swing to a common printing point against a platen I. For illustrative purposes the type action and, in fact, all standard typewriter parts, may be of the Underwood type.

The operating levers 3 form part of an automatic control mechanism of the Hooven type. Each operating lever is formed with a slot '8 in which a supporting pivot rod 9 is received. The inner, rear ends of the slots 8 extend substantially horizontally so that the operating levers can be slid back and forth upon the rod '9. Each operating lever is urged normally to a rearward or inactive position by a leaf spring Ill which i constitutes one tooth of a comb II. I l is fixed in a stationary rod [2.

At the rear end of each operating lever 3, there is provided a shifting or displacing pin I3. Each pin comprises a body portion M which is slidable in a bore formed in a central car of the lever 3, and a lower reduced, stem portion I6 which is slidable in a bore formed in a lower ear I! of the lever 3. The pin is also includes an upper stem portion which is surrounded by a coil spring [8. The coil spring is bears against the upper end of the pin body [3 and extends into a bore formed in an upper ear l9 of the lever 3. The upper end of the spring [8 bear against a screw which is threaded into the bore of the upper ear IQ of the lever 3.

The comb The lower end of the pin l3 normally bears with light spring pressure against a record tape 2| of paper or other suitable material, which has selector perforations formed in it.

When a perforation of the record comes under One of the pins l3, the pin is projected downward through the record and is engaged by a toothed displacing drum 22. The drum is made fast upon a shaft 23 which is constantly rotated in a clockwise direction, as viewed in Fig. 1. The displacing drum acts upon the pin l3 to thrust the lever 3 forward from its normal, idle position against the resistance of the spring Ill.

The lever 3 has fixed upon it a rigid upstanding part in the form of an arm 24. The arm 24 normally stands clear of an actuator bar 25 which forms part of an actuator 26. When the operating lever 3 is shifted forward, however, to carry the arm 24 to the position indicated in dot and dash lines. as 24a in Fig. 1, the arm is located in the path of the actuator bar 25 so that it will be engaged and forced downward by the bar, causing the lever 3 to be rocked in a clockwise direction about the pin 9 as a fulcrum. The lever 3, as it travels downward, exerts a pull through the link 2 upon the associated lever i, and thereby causes the type bar 5 to .be swung to printing position.

The actuator bar 25 is connected rigidly at its ends to arms 2! which form parts of the actuator, and which are pivotally supported by a shaft 28. A pitman 29 is pivotally connected at 39 to one of the arms 21, and at its opposite end is formed with a collar 3! which embraces an eccentric 32 fast on a constantly driven shaft 33. It will be readily apparent that each revolution of the shaft 33 produces a reciprocation of the actuator 25. So long as no operating lever 3 has been displaced in a forward direction to locate its arm 24 in the path of the actuator bar 25, the actuator simply reciprocates idly, but as soon as one of the levers 3 has been displaced to its forward position, an operation of that lever is effected in the manner which has already been described, the actuating stroke of the actuator being the down stroke.

As an incident of the clockwise rocking of a lever 3, the tail of the lever is lifted away from the record 2| so that the projected pin I3 is carried clear of the perforation in the record 2|. The record is advanced at this time so that the pin when it is again carried downward by the lever will be caused to rest on top of the record until another perforation of the record comes beneath it.

The mechanism thus far described is substantially of conventional construction.

For manually controllin the typing a novel unit 35 is provided in place of the normal typecured in fixed positions.

g. {writerkeyboard. This unit comprises across bar 36, a frame stirrup 31 and connecting brackets '38 between the ends of the frame stirrup 31 and the cross :bar 36. The cross bar 36 and the frame stirrup 81 are secured at their ends to the opposite sides of the machine frame (not shown); The cross bar 36 includes an upper arm 39 formed with numerous slots 39a in which displacing bell crank levers All are pivotally mounted upon a pivot rod 4|. There is a displacing lever M'for each of the operating levers 3, and each operating-lever is provided with a pin 42 which stands just in front of the upwardly reaching arm 43 of the displacing lever.

The-cross bar 36 includes a horizontal arm 44, whichis also provided with numerous slots 45. In-each slot there is mounted a detent and tripper mechanism for one of the displacing levers it. Each displacing lever includes a forwardly reaching arm 45 at the forward end of which there is a laterally extending finger or lug 41. The finger 41 normally rests upon a shoulder 480i a'detent lever 49.

Each lever 46 is urged clockwise by a tension coil spring 50, the spring being connected at its upper end to the forwardly reaching arm 45 of the lever and at its lower end to a stationary plate The plate 5l'extends across the machine and is connected at its ends by means of screws 52 throughspacerblocks 53 to the cross bar 36. r

The detent 69 is rockably mounted upon a pivot rod 54 and is urged-counter-clockwise by a tension coil spring 55. The spring 55- is com nected at its rear end to the lower end of the detent 4-9 and at its forward end to a plate 56 which is secured to thebottomof the frame stirrup 31. counterclockwise movement of the detent is normally limited by engagement of'the finger t with a face 57' of the detent, while clockwise movementof the lever 46- is normally limited by engagementof the finger 41 with the shoulder 48 ofthe detent. A key actuated tripper is provided for each detent.

The keyboard consists of a multiplicity of keys 58, each having a stem 59. All-of the stems 59 of a single row of keys-pass between two plates or bars 60 and SI.

These plates extend from side to side-of the machine and are se- The plates are formed with mating guides notched for the reception of stems 59.

Below the plates 6!! and 61-, the stems of the firstthird and fourth rows are bent to bring them into alignment with the stems oft-he second row, and all of the stems have straight portions at their lower ends. The lower ends of the stems 59 are flattened or reduced in width to form stop shoulders 62'. The reduced portions of the stems extend through slots formed in a plate- 63 that extends from side to side of tionary plate E315. that extends. across the machine.

'liheslower end of the; each. stem. 5.9; rests; upon a iQIiWfiEdlY; re ching a m: of a. bell, crank lever at, fin hlener forming part of atripperior'an associ ated; detent. Each; bell crank lever -6.-',I. is pivotally mounted upon a pivot rod .68 and is disposed in one of the slots of the arm 45. Each lever 61 also includes an upwardly extending arm which is pivotally connected through a pin 69 with a pull link it. The pull link it is formed with a notch H, the rear, shouldered face of which normally engages behind a finger E2 of the detent A9. The pull link 'lil also includes a tail portion '53 which extends for a substantial distance to the rear of the notch T I; and underneath the finger 41 of the lever 40.

A tension coil spring 73 is connected at its lower end to the pull link Til and extendsupwardly and rearwardly, being connected at its upper, rear end to a stationary plate M which extends across the machine, and which is supported through brackets #5 from the upper arm 38 of the cross bar 36. The spring 13 urges the pull link Ill upward and rearward and thus maintains the link at all times in engagement with the fingerli, and the lever 67 at all times in engagement with the stem 59.

When a key 58 is depressed, the associated lever 61 is rocked clockwise a short distance, and pulls the pull link It toward the right (Figs. 1 and 3) The pull link ill pulls with it the detent 49, swinging the detent in a clockwise direction, and withdrawing the supporting shoulder 48 from beneath the finger ii? ofthe displacing lever 40. As soon as thisoccurs, the spring acts to swing the displacing lever 43 sharply in a clockwise direction. The arm l3 of the lever ill engages the pin 42 of the associated operating lever 3, and shifts the operating lever forward until the lever is arrested by engagement of the rear endof its. slot 8 with the supporting pivot pin 9- as inv Fig. 3. This. carries the member 24 of. the operatinglever forward from the full line position ofv Fig. .l to the position designated 24a in that figure. At the next descent of the actuator 26, the actuator bar 2.5 engages the member 26 and drives itdownward. until the parts have assumed a position like that illustrated in Fig. 4. This movement of, the operating. lever 3. is effective through the link 2, the lever l and the bell crank 4 to operate the associated type barfor printing.

The depression or clockwise rocking of the operating lever 3 performs another important function. As the pin 42 is carried downward by the lever 3 it engages a sloping cam surface 88 of the lever 46. As. the lever 3 is moved downward under power actuation, therefore, it rocks the lever id counter-clockwise and restores it to its original position. As soon as the finger t'iof the lever til moves alcove the surface of the shoulder d8 of the detent 4d, the detent snaps back to locate the shoulder 38; beneath the finger ll. and detain the lever it in its normal position. By thismeans the spring 56 is supplied by power with the energy for displacing the lever 3 in a forward direction. against the resistance of the spring iii when the detent 49 is next tripped.

It should be observed that, although the pull link ll isv initially engaged with the finger. '32 of the detent it, as soon as the displacing lever All is released by the shoulder 48, the finger ll. of the lever in forces the pull link 10 downward and causes it to release the finger 12. of the detent 9. The detent 49 is now free to return to detaining position assoon as the lever 40- has been restored to normal position. This is an important.- point because it insures. against the unintentional double printing of. a letter.

away from detaining position until the release of the associated key by the typist, and the typist would be very likely to delay the release of a key at times, and thereby produce the unwanted double printing of a letter.

By temporarily breaking the connection between a pull link 10 and the detent 49, assurance is provided that the displacing lever 40, when restored to normal position, will be retained in that position, and that the associated operating lever 3 will resume, and remain in, its rearward, inefiective position until the pull link notch, H, has been reengaged with the finger 12.

A machine constructed and arranged as described is adapted to be used either for automatic typewriting under the control of the record tape or for power typewriting under the control of the keyboard as desired. The utility of the invention is not, however, confined to typewriters which include the tape control feature. The invention may be employed to advantage for keyboard controlled power typing whether or not the tape control mechanism is present in the machine.

I have described what I believe to be the best embodiment of my invention. I do not wish, however, to be confined to the embodiment shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. In a power operated typewriter, the combination with several keys and type bars, of a reciprocating power operated actuator, operating levers connected to operate the respective type bars, and having power transmitting parts engageable by the actuator, springs urging the respective power transmitting parts to their normal, inactive positions, displacing levers operable to shift the respective power transmitting parts into positions to be engaged and operated by the actuator, displacing springs for the respective displacing levers, detents for the respective displacing levers holding them normally in retracted, inefiective positions against the force of their displacing springs, springs urging the respective detents toward their detaining positions, key operated trippers for the detents including rockable pull links normally operatively engaged with the detents but disengageable therefrom in response to displacing movement of the respective displacing levers so that each detent may be restored to its normal, detaining position in advance of restoration of the associated key, and cam means operated by each operating lever as an incident of-the power operation of the operating lever for returning a tripped displacing lever to its normal, detained position, and for reloading its displacing spring.

2. In a power operated typewriter, the combination with the several keys and type bars, of a reciprocating power operated actuator, displaceable operating levers connected to operate the respective type bars, springs urging the respective operating levers to their normal, inactive positions, displacing levers operable upon the respective operating levers to shift the operating levers into positions to be engaged and operated by the actuator, displacing springs for the respective displacing levers, detents for the respective displacing levers holding them normally in retracted, ineiiective positions against the force of their displacing springs, springs urging the respective detents toward their detaining position, key operated trippers for the detents including rockable pull links normally operatively engaged with the detents but disengageable therefrom in response to displacing movement of the respective displacing levers so that each detent may be restored to its normal, detaining position in advance or" restoration of the associated key, and cooperating cam means on the associated operating and displacing levers for returning a tripped displacing lever to its normal, detained position, and for reloading its displacing spring as an incident of the power operation of the operating lever.

3. In a power operated typewriter, the com bination with the several keys and type bars, of a reciprocating power operated actuator, displaceable operating levers connected to operate the respective type bars, springs urging the respective operating levers to their normal, inactive positions, displacing levers operable upon the respective operating levers to shift the operating levers into positions to be engaged and operated by the actuator, displacing springs for the respective displacing levers, detents for. the respective displacing levers holding them normally in retracted, ineffective positions against the force of their displacing springs, key operated trippers for the detents, and cooperating cam formations on the associated operating and displacing levers for returning a tripped displacing lever to its normal detained position, and for reloading its displacing spring as an incident of the power operation of the operating lever, each of said trippers including a pivoted pull link normally spring held in operative engagement with the associated detent but disposed to be disengaged therefrom by a tripped displacing lever so as not to delay the restoration of the detent to detaining position.

4. In a power operated typewriter, the combination with the several keys and type bars, of a reciprocating power operated actuator, displaceable operating levers connected to operate the respective type bars, springs urging the respective operating levers to their normal, inactive positions, displacing levers operable upon the respective operating levers to shift the operating levers into positions to be engaged and operated by the actuator, displacing springs for the respective displacing levers, detents for the respec tive displacing levers holding them normally in retracted, ineii'ective positions against the force of their displacing springs, key operated trippers for the detents, and cooperating cam formations on the associated operating and displacing levers for returning a tripped displacing lever to its normal detained position, and for reloading its displacing spring as an incident of the power operation of the operating lever, each of said trippers including a pivoted pull link normally spring held in operative engagement with the associated detent but disposed to be disengaged therefrom by a tripped displacing lever so as not to delay the restoration of the detent to detaining position, the pull link being adapted to return to operative engagement with the detent upon release of the operated key, after the detent has been restored to its detaining position.

5. In a power operated typewriter, having a set of keys and type bars, a reciprocating power operated actuator, displaceable operating levers connected to operate the respective type bars, and springs urging the respective operating levers to their normal inactive positions, in combination, displacing levers operable upon the respective operating levers to shift the operating levers into positions to be engaged and operated by the actuator during manual typing, displacing springs for the respective displacing levers, detents for the respective displacing levers holding them normally in retracted, ineffective positions against the force of their displacing springs, springs urging the respective detents toward their detaining positions, key operated trippers for the detents including rockable pull links normally operatively engaged with the detents but disengageable therefrom in response to displacing movement of the respective displacing levers so that each detent may be restored to its normal, detaining position in advance of restoration of the associated key, and cooperating cam formations on the associated operating and displacing levers for returning a tripped displacing lever to its normal detained position, and for reloading its displacing spring, as an incident of the power operation of the operating lever.

6. In a power operated typewriter, the combination with a key and type bar, of a reciprocating power operated actuator, a displaceable operating member connected to operate the type bar, a spring urging the operating member to a normal, inactive position, a displacing lever operable upon the operating member to shift the operating member into position to be engaged and operated by the actuator, a displacing spring for the displacing lever, a detent for the displacing lever holding it normally in retracted, ineffective position against the forceof its displacing spring,

' a spring urging the detent toward its detaining position, a key operated tripper for the detent including a rockable pull link normally operatively engaged with the detent but disengageable therefrom in response to displacing movement of the displacing lever so that the detent may be restored to its normal, detaining position in advance of restoration of the associated key, and cooperating cam formations on the operating member and the displacing lever for returning the tripped displacing lever to its normal detained position, and for reloading the displacing spring as an incident of the power operation of the operating member by the actuator.

7. In a power operated typewriter, the combination with a key and type bar, of a reciprocating power operated actuator, a displaceable operating member connected to operate the respective type bar, a spring urging the operating member to a normal, inactive position, a displacing lever operable upon the operating member to shift the operating member into position to be engaged and operated by the actuator, a displacing spring for the displacing lever, a detent for the displacing lever holding it normally in retracted, ineffective position against the force of its displacing spring, a key operated tripper for the detent, and cooperating cam formations on the operating member and the displacing lever for returning the tripped displacing lever to its normal detained position, and for reloading the displacing spring as an incident of the power operation of the operating member by the actuator and the tripper including means responsive to the displacing lever, temporaril to break the operative connection between the tripper and the detent after the displacing lever has been released, and means to reestablish such connection only after the detent has been restored to detaining position.

STEPHEN B. PETIT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,206,534 Guthrie Nov. 28, 1916 1,769,624 Evans July 1, 1930 FOREIGN PATENTS Number Country Date 335,645 Germany of 1921

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