US2018317A - Power operated typewriter - Google Patents

Description

' Oct. 22, 1.935.

w. J. PASINSKI POWER OPERATED TYPEWRITER Original Filed Jan. 25, 1930 3 Sheets-Sheet 1 a m i? mJ mm l A N6 HM a& PM I Oct. 22, 1935. w. .1. PASINSKI 2,013,317-

POWER OPERATED TYPEWRITER Original Filed Jan. 25, 1930 3 Sheets-Sheet 2 OR a/ierd Pawns/11' fiat Mil ATTORNEYS Oct. 22, 1935. w, PASINSK. 2,018,317

POWER OPERATED TYPEWRI TER Original Filed Jan. 25, 1930 s Sheets-Sheet 3 Fig. 4.

Y INVENTOR Mz/ferd Pas/n54;

7 53 lgbmaa ATTORNEYS Patented Oct. 22, 1935 UNITED STATES 2,018,317 rowEa OPERATED .TYPEWRITER Walter J. Pasinski, Howell, Mich., assignor to Burroughs Adding Machine Company, Detroit, Mich a corporation of Michigan Original application .lanuary 25, 1930, Serial No. 423,338. Divided and this application June 11, 1934, Serial No. 729,943. In Great Britain January 25, 1930 Claims. (CL 197-17) This invention relates to a power operated typewriter. This application is adivision of my co pending application, Serial No. 423,338, filed January 25, 1930.

The general object of the invention is to pro-- vide an improved typewriter of this type.

Another object is to provide a typewriter having improved means for shifting the platen by the power. v

A further object is to provide a machine of the foregoing class that will print characters of uniform distinctness independently of the nature of the key depression and independently of whether large or small characters are being printed.

A more specific object is to provide a typewriter wherein the platen is shiftable for printing of small and large characters and the type bars are moved to printing position with automatically increasing force when the platen is in position for printing of" the large characters.

Other objects and advantages of the invention will appear from the specification and drawings. An embodiment of the invention is shown in the drawings, wherein- I Figure 1 is a right side elevation of the typewriter with certain portions cut away to show the power drive;

Fig. 2 is a fragmental section and elevation taken from the left side of the machine;

Fig. 3 is a partial sectional elevation of the keys that control the platen shift;

Fig. 4 is a partial rear elevation of the motor governor;

Fig. 5 is a detailed perspective of the driving drum for the platen shift; and

Fig. 6 is a, section through the drum of Fig. 5. The typewriter is provided with a frame l5 (Fig. 1) supporting a raceway IS on which is mounted a traveling paper carriage C supporting a platen R The carriage is moved across the machine in the usual manner under the control of an escapement mechanism including a ratchet wheel I l, the details of the escapement mechanism not havingbeen illustrated or described as such mechanisms are well known in the art.

about the platen 1?.

Power drive Themachine is preferably driven by an electric motor (Fig. 1) -on the armature shaft 2| of which is a worm 22 meshing with a worm wheel 23. The worm wheel 23 drives a shaft 24 through a releasing clutch 25, the shaft 24 having a bevel gear 26 on its end meshing with another bevel gear 21 on the main drive shaft 28 of the machine. When-the typewriter is beingoperated, the motor drives the main drive shaft 28 continuously through the connections above described.

The releasing clutch is provided in order to prevent damage to the machine in the event it should become jammed in any way, such an expedient being desirable because of the relatively light construction of many of the typewriter parts. The'construction of this clutch, which is more particularly described in my aforesaid original application, is such as to enable the worm wheel 23 to drive the shaft 24 under all normal conditions but, if a resistance should be encountered above a predetermined amount, the shaft 24 is released from the motor allowing the motor to rotate without driving the machine.

The speed of the motor'is regulated by a gov- 2 ernor illustrated in detail in Fig. 4. Fixed to the armature'shaft 2| is a collar 30 carrying a pair of centrifugal members 3| bearing against the end of a plunger 32 slidably, mounted in an extension of the collar 30. The plunger 32 bears against an insulating plate 33 on the end of an angular switch arm 34 pivoted at 35 on a lug 36 projecting upwardlyv from a stationary support 31 bolted to but insulated from the motor housing by a bolt 38. The switch arm 34 carries a contact 39 urged by a spring 40 attached to the switch arm into engagement with stationary contact 4| mounted on and insulated from the support 31. The tension of spring 40 may be varied by means of an adjustable thumb nut 42 mounted in the.

support 31, one end of spring 40 being connected to an arm 43 carried by said nut.

As the speed of the motor increases, the centrifugal members 3| .fly outward and push the plunger 32 to the right as viewed in Fig. 4. This .moves the switch arm 34 clockwise and tends to separate the contacts 39 and 4| thereby opening the motor circuit and shutting off the supply of current to the motor. The motor speed then decreases until the centrifugal members 3| move back to normal to allow the switch contacts to close. This action takes place very rapidly, the

contacts vibrating back'and forth to maintain just thev proper amount of -,current to enable the speed of the motor to remain substantially constant. Different constant speeds can be had by adjusting the tension of spring 40. While this 'form of governor is preferred, it is to be understood that any othersuitable type could be used.

- Type bar mechanism The type bars (not shown) are moved to printin Position by the power drive under the control of key-levers 56 actuated by keys 5| located in the keyboard at the forward part of the machine (Figs. 1 and 3). In order that the type bars may be driven to printing position, they must be momentarily connected to the power drive and a novel construction for accomplishing this purpose is'fully shown and described in my. said original application.

Briefly, a series of ratchet wheels 60 are mounted on the continuously rotating drive shaft 28, there being a ratchet wheel for each type bar. Each type bar is driven to printing position by being momentarily connected to its ratchet wheel 60, and this connection is effected by depression of the key 5| for actuating the particular type bar. Each type bar can be connected to its ratchet wheel 60 by a pawl 6| pivotally supported by a lever 62 that rocks about the axis of the shaft 28 and is connected to the type bar in such a way that rocking movement of the lever 62 in clockwise direction moves the type bar toward printing position.

The pawl 6| is urged clockwise toward a position for engaging the ratchet wheel 60 by a spring 63 (Fi 2), but this pawl is normally prevented from engaging the ratchet wheel by a detent 64 having a lip 65 that projects in front of the nose of the pawl. The arrangement is such that when the key lever 50 is rocked clockwise by depression of a key 5|, the detent 64, through suitable connections more particularly described in my said original application is rocked clockwise to remove its lip 65 from in front of the nose of the pawl 6|. When this occurs,'the spring 63 snaps the pawl 6| into engagement with the rotating ratchet wheel (Fig. 2) therebymoving the lever 62 clockwise and, in turn, moves the type bar toward printing position. This movement, which is quite sudden, continues until the type bar is moved into close proximity to the platen whereupon the driving connection is disabled. The type bar and associated parts have enough momentum by that time to cause the bar to continue its movement until it reaches the printing position.

Disconnection-of the driving connections from the type bar is accomplished through an irregularly shaped reversing or disconnecting member 66 that is pivoted on the end of lever 62 and to the forward end of which the spring 63 controlling the pawl 6| isconnected. The member 66 has a tail piece 61 operating in a slot in a comb plate 68 (Fig. 2), and'when the lever 62 is rocked clockwise to drive the type bar to printing position, and as the type barreaches its position wherein it is to be released from the drive, the tail piece 61 of the member 66 contacts the top of the comb plate slot so that the member 66 is rocked or flipped counterclockwise. This swings the spring 63 across the center of the pivot of the pawl 6| so that the spring then tends to rock the pawl 6| clockwise out of engagement with the ratchet wheel 60. With ,this arrangement, the pawl is positively, quickly and completely knocked out of engagement with the ratchet wheelby a projecting portion 69 of the member 66 which, I

during the rocking or flippingmovement of the member 66, strikes the lower face of the rear extension of the pawl 6| with a hammer-like action at about the time or shortly after the direction of action of the spring 63 is changed.

During the foregoing operation, the detent 64' is reset or released to the position shown in Fig. 2 so that the pawl 6| again assumes the position shown in that figure. v V

In the return of the type bar to its non-print- 5 ing position, after release of the driving mechanism, the lever 62 swings counterclockwise toward its normal position of Fig. 2. As the lever 62 thus swings, the member 66 moves with it and its tail piece 61 engages the bottom of the slot 1 in comb plate 68 so that the member 66 is flipped clockwise to its normal position thereby swinging the spring 63 back across the pivot of pawl 6| so that the spring 63 again acts to rotate the pawl toward engagement with the ratchet wheel 5 60, such engagement being prevented, however, by the lip 65 with the detent 64 which, having been returned to normal position, blocks the pawl and holds it in inactive position.

It will thus be seen that when the key 5| is 20 depressed, the type bar corresponding to the key is connected to a continuously rotating ratchet wheel, which drives the type bar toward printing position, the type bar being automatically disconnected just prior to the time it reaches print- 25 ing position. The connection for each-type bar is individual and the construction is such that the connection and disconnection can be made very rapidly and efliciently and without requiring anything but a very light key depression because 3 the depression of the key operates only very light parts.

Escapement mechanism As previously mentioned, the paper carriage is moved across the machine under the control of an escapement mechanism including a ratchet wheel M. This ratchet wheel is controlled by escapement dogs l6 (Fig; 1) that are operated by an escapement baii (not shown), the construction 40 being very similar to that employed on a Royal typewriter. In order for the carriage to be letter spaced, the bail is interconnected by suitable connections (more specifically set forth in my said original application) with the type bar operating levers 62, so that when each such lever is rocked clockwise, as hereinabove described, to move its type bar to printing position, the bail will be moved to actuate the escapement dogs 'lll to permit movement of the carriage by the usual spring drum. The carriage is thus letter spaced each time a type bar is moved from printing position. The carriage can also be letter spaced by means of the spacing bar 80. This spacing bar may be interconnected with the escapement bail in any 55' desired manner, but preferably as shown and described in my said original application.

Power operated platen shift ing to supply the force by depression of a key. 70

Referring to Fig. 2, the carriage C with the platen P is supported on side plates 90 pivoted at 9|. By rocking these plates counterclockwise,

the carriage can be moved upward from its Fig. 4

2 position,' the upward movement being limited by a projection 92 that engages an adjustable stop screw 93 on the typewriter frame. The side plates are normally urged counterclockwise by a spring 94 connected at one end to the machine frame and at its other end to a lever 95 pivoted at 96 to one of the side plates and having a lip 91 projecting into a hole 98 in the side plate. This spring is not strong enough to raise the platen, but it counteracts some of the weight of the carriage and platen and assists in making the raising operation easier. It also affords a yielding connection that serves a purpose that will be later described.

The side plates 90- are rocked counterclockwise to raise the platen by means of a link I00 that is' pulled to-the right as viewed in Fig. 2 by means of a flexible cable IOI wound around a drum I02 on the main drive shaft 28 of the machine. This cable is normally loose on the drum, but it may be tightened by depression of a platen shift keyin the following manner.

The platen shift key I03 shown in Fig. 3 is carried by a lever I04 pivoted on the shaft I05 and provided with a lateral lug I06 adapted to engage a projection I01 on a lever I08 pivoted on the shaft I09. This lever I00 carries a pin I I0 operating in a slot I II in the end of the link I00 so that the lever has a slight movement relative to said link. The lever I08 has an arm II2 mounted rigidly on it, the other end of the flexible cable IOI being connected to the arm II2. When the platen shift key is depressed, the lever I08 is rocked clockwise carrying the arm' II2 with it which tightens the cable IOI about the drum. The drum immediately grips the cable and pulls the link I00 to the right. This rocks the side plates 90 counterclockwise and raises the platen to-its upper position. When the key is released the cable is loosened and the platen returns to its lower position under its own weight and the weight of the paper carriage. A pin and slot connection between arm I I 2 and lever I08 permits adjustment 'of slack in cable I 0I (Fig. 2). v

The pin and slot connection between the lever I00 and the link I00 permits the lever to move relative to the link to tighten the cable about the drum,-but in the event the drum does not operate to raise the platen the platen may be raised by hand through continued depression of the platen shift key which causes the stud I I0 to contact the end of the slot III and move the link I00 to the right to raise the platen.

If it is desired to hold the platen in raised position during a number of operations of the type keys, the platen shift key must be held depressed in which case the drum must rotate relative to the flexible cable. Such action is permitted and successful operation is obtained by choosing the right materials, it having been found that by making the drum out of a self-lubricating fibre and by making the cable out of raw hide the cable will operate to raise the platen and, at the same time, will permit enough slipping to occur to enable the drum to rotate when the platen shift key is held depressed.

Provision is made for locking the platen shift keyin depressed position and for this purpose a supplementary key H3 is provided mounted on a lever I I4 pivoted on shaft I09. This lever has an arm I I5 connected to a wire I I6 that controlscertain parts of the machine whose functions it is not necessary to describe in the present application.

Referring to Fig. 3, the key lever II4 carries a stud III adapted to engage the end of a latch II8 pivoted at II9 to the machine frame and urged clockwise by a spring I20. This latch has a notch I2'I adapted to engage over a stud I22 on the lever I04 of the platen shift key I03.

When the key H3 is depressed the stud II'I contacts the edge of latch II8 which in turn contacts the stud I22 and moves the platen shift 5 key lever I04 downwardly. This movement continues until the latter has been moved to its operated position whereupon the notch I2I in the latch II8 slips over the stud I22 and locks the lever I04 in lowered position. In order to 10 release the lever I04, it is merely necessary to depress the platen shift key I03 which moves the stud I 22 downwardly a slight distance and thereby releases the latch IIO which is snapped to its upper. or released position by the spring 15 I20. This extra movement of the platen shift key is permitted by theyielding action of the spring 94 and arm (Fig. 2) to the side plates of the platen shift frame. Although the platen cannot move up any farther, the sprlngj94 will-20 yield. so that the key I03 can befdepiessedi This spring also absorbs the shocks of violent'- key depressions.

Automatic control to obtain uniform printing Q It will be apparent that, when the platen is in the position where the large characters are operative, more force will be required to obtain a printing impression than when the small 30 characters are employed. It is highly desirable to have all the printing impressions uniform. The present machine is provided with a construction for automatically increasing the force with which the type bars are moved to printing 35 position when the large characters are employed.

Connected to a portion of the platen frame that is raised as the platen is moved to its upper position is a link I30 (Fig. 2) that is, in turn, 40 connected through a spring I3I (Fig. 4) to a rod I32 projecting through an extension I33 of the switch arm 34 of the speed regulator of the electric motor. The rod I32 has a head I34 which, when the rod is raised contacts the ex- 45 tension I33 to move the switch arm. When the platen is raised, the link I30 is raised with it which raises the rod I32 and rocks the switch arm 34 counterclockwise. This tends to increase the resistance to the centrifugal action 0 of arms 3I and increase the speed of the motor,- which, of course, increases the speed of the main drive shaft of the machine. It will be evident that, when the type bars are connected to ratchet wheels that are being driven at a higher rate of 55 speed, the type bars will be thrown to printing position with more force than under conditions when the ratchet wheels are revolving more slowly. In other words, when the platen is raised to its upper position the motor is speeded up slight- 60 ly to impart more driving force to the type bars so that the printing impression of the large type will be the same as that of the small type, the

' entire operation being automatic.

This automatic control of the speed of the 65 motor can be varied through its connection illustrated in Fig. 4. The link I30 has an offset" portion I35 carrying an adjustable screw I30 that contacts 2. lug I31 (Fig. 4) on an arm I33 pivoted on the link I30. The arm is urged into en- 7 gagement with the screw by a spring I39. By adjusting the screw I36, the distance of the head I34 below the extension I33 can be varied so as tovary the effect of the raising of the link I30 a on the switch lever.

I- claim:

1. A typewriter having a platen, a power driving means, mechanism adapted to be actuated by said power driving-means to raise said platen, said mechanism including a power operated drum, a flexible belt surrounding said drum, and means for tightening said belt on said drum to cause said power driving means to raise the platen.

2. A typewriter having a platen, a power driving means, mechanism operable by said power driving means to raise said platen, and manually operable means for conditioning said mechanism to cause it to raise said platen, said manually operable means having connections for automatically raising said platen manually in the event said power operated mechanism does not function.

3. In a typewriting machine having a shift key for bringing capital letters into function and a power roller driven by a, variable speed electric motor; means responsive to a depression of said shift key for accelerating said motor and said power roller when a capital letter is to be struck.

4. A power operated typewriter provided with impression making means having large and small type, power driving means, driving connections 'operated by said power driving means for moving said impression means to impression making position, said machine being normally conditioned to cause the impressions to be made by said small type, means for conditioning the machine to make impressions from said large type, and speed controlling means acting automatically as said machine is conditioned to make impressions from said large type to increase the speed of said power driving means, said speed controlling means also acting to decrease the speed of said power driving means when the machine is returned to small type printing condition.

5.. A. power operated typewriter having a platen,

a plurality of movable type bars having large and'small type, an electric motor having connectionsfor driving said type bars to printing position, said typewriter being normally conditioned to cause a printing impression to be made by the small type of said type bar, case shifting means for changing the relative position of said platen and type bars to cause printing impressions to be made by said large type as said type bars are moved to printing position, and means conditioned by said case shifting means for automatically increasing the speed of said electric motor when said typewriter is conditioned to print from said large type.

- 6. A power operated typewriter having a platen, a plurality of movable type bars having large and small type, an electric motor having connections for driving said type bars to printing posimeans conditioned as an incident tion, a governor for governing the speed of said motor, said typewriter being normally conditioned to cause the printing impressions to be U made by the small type of said type bars, case shifting means for changing the relative position of said platen and type bars to cause printing impressions to be made by the large type, and to a "change in relative position between said platen and type bars for automatically changing the condition of said governor to vary the speed of said motor.

7. A power operated typewriter having a platen, a plurality of movable type bars having large and small type, an electric motor having connections for driving said type bars to printing position, said typewriter being normally conditioned to' cause the printing impressions to be made by the small type of said type bars, case shifting means for changing the position of said platen relative to said type bar to cause printingimpressions to be made by the large type, and means conditioned automatically by said platen as it isshifted .for varying the speed of said motor.

8. A typewriter having a platen, a power driving means, mechanism operated by said driving means to raise said platen, said mechanism including a power driven member connected to said driving means, means for operatively connecting said member to and disconnecting it from said platen. means for operating said connecting means to operatively connect it to and disconnect it from said member to raise and lower said platen, said connecting means being so constructed and so arranged that it slip-engages said member in the raised position of said platen.

9. In a typewriter, power driving means, a platen, type bars having small and capital letter type, means connecting said driving means to said type bars, means adapted to be connected to said driving means for shifting said platen, a shift key depressible for effecting connection of said latter means with said driving means to move said platen to a position for the printing of capital letters, and means responsive to depression of said shift key for increasing the speed of said driving means.

10. In a typewriter, power driving means, a platen, type bars having small and capital type, means for drive-connecting said type bars to said driving means, means adapted to be connected to said driving means for effecting relative shift movement between said platen and type bars to relatively position the same for printing capital letters, a depressible shift key for eifecting said connection of said latter means, and means responslve to depression of said shift key for increasing the speed of said driving means.

' WALTER J. PASINSKI.

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