US1921490A - Typewriting machine - Google Patents

Description

Allg. 8, 1933. B .CE sTlcKNEY 1,921,490

TYPEWRITING MACHINE Original Filed May 27, 1927 2 Shefets-Sheet l vAug. 8, 1933. B C,q ST|KNEY 1,921,490

TYPEWRITING MACHINE Original Filed May 27, 1927 2 Sheets-Sheet 2 Patented Aug. 8, 1933 PATENTv OFFICE TYPEWRITING MACHINE Burnham C. Stickney, Elizabeth, N. J., assignor to Underwood Elliott Fisher Company, New York, N. Y., a Corporation of Delaware Application May 27, 1927, Serial No. 194,591 Renewed April24, 1931` 6 Claims.

This invention relates to typewriting machines, and more specically to a motor-driven repulser operative to 'forcibly restore an escapementrocker after each typing impact and' drive the universal bar against the type-bar to repulse or catapult the type-bar from the typing position of the platen and more quickly effect the letterspacing release for the motor-driven carriage.

The Underwood carriage-feeding mechanism includes a type-bar actuated universal bar that vibrates an escapement-rocker carrying a holding dog and a stepping dog, the latter normally holding a tooth of an escapement-wheel, and the holding dog provided with a beveled face that r holds said tooth during the stepping interval of the released stepping dog, as at the end of a key-stroke. rIhe universal bar, having a direct connection to the escapement-rocker, operates the latter by a very short movement from the type-barsv at the end oi the key-stroke; hence the type-bars are projected by the key-levers to a point very close to the typingace of the platen .before they pick up the universal bar to vibrate the rocker andleffect a letter-space feed of the carriage. It is this quick, snappy vibration of the Yes'capement-dogs before and after the typeimpact that promotes speed in typing.

A type-bar usually is sluggish at the instant of type-impact,V due to mechanical sacrifices made 0 for accelerationl of motion in front-strike typerocker at the end of the key-stroke, drive thev universal bar to repulse the type-bar and vaccelerate the return movement of the rocker to release the escapement-tooth and permit the next advancing tooth of the escapement-wheel to engage the stepping dog4 for a letter-space move- To effect this reaction ofthe beveled dog,

ment. the carriage-tension is necessarily high and this tension must be overcome by the operator at every carriage-return movement, but it is this combination of type-bar-actuated universal bar 5 and beveledholding dog that gives the Underwood typewriting machine its reputation for speed in manipulation.

The beveled face of the holding dog i'n vibrating into contact with the edge of an escapement-wheel-tooth, serves as a stop for the forward movement of the rocker and is annoying to some operators who allow the lingers to linger upon the keys, besides being variable in its action under erratic manipulation of the keys. One yfeature of this invention includes the elimination of the beveled face and the substitution of f a flat dog for holding the escapement-tootli at the end of a key-stroke, the movement of the rocker being limited in both directions of its movement by a pallet movable with the rocker and co-operating with a rotary driver that positively controls the throw of the rocker and the associated Y escapement-dogs regardless of the speed in manipulation of the keys.

One purpose of the present invention Yis to im'- prove upon the highly developed carriage-feeding mechanism of the Underwood typewriter by retaining the speed-producing features, and further providing a motor-driven accelerator for the voperative at the end of the down stroke of the keys to speed up the let-off of the holding dog to more quickly yrelease the carriageand simultaneouslyrepulse and speed up the return of the type-bar after a type-impression; to provide an inactive power-drivenv driver rendered operable vbythe rocking of the key-actuated escapementrocker in typing and rendered inoperative by the reverse or return movement of the rocker; to 'provide a power-driven toothed driver cooperative with a tooth-escaping pallet movable with the rocker and operative to first release a tooth of the driver at the endfof a key-stroke,

and inY turn be driven by' a tooth to rock and restore Asaid rocker and universal bar torepulse the type-bar; to provide a driving element havying afstored-up reserve power that is operative at all times to respond step by step to the keynection to normalpositions independently of the keys and thus eliminate, to a large extent, the Y 'prior restoring spring-tensions, correspondingly soften the touch vat the keys, and provide an `easier manual operation of returning the carriage at the end of each line.

Other features andV advantages will hereinafter appear.

vIn the accompanying drawings, l Figure lisa longitudinal vertical section apner by screws 33.

proximately through the center of an Underwood typewriting machine, showing such parts of the type-bar action and carriage-feeding mechanism necessary to illustrate the application of the present improvement to the standard machine parts. Y

Figure 2 is a full-size front elevation of the carriage-feeding unit upon a bracket detachably secured to the frame of the machine.

Figure 3 is a side elevation of Figure 2, showing the escapement-rocker-driving connections assembled in an operative relation to the carnage-feeding elements.

Figure 4 is an enlarged diagrammatic View, showing the normal relation between the driving element and the controlling pallet movable with the escapement-rocker.

Figure 5 is a view similar to Figure 4, showing the pallet vibrated to a position at the instant of type-impact, while one member of the pallet is about to `release a tooth of the driver and another tooth of the driver is about to restore the pallet and restore the escapement-rocker.

Figures 6, 7 and 8 are diagrammaic views illustrating the diierent positions assumed by the holding and stepping dogs in relation to two teeth of the escapement-wheel; Figure 6 shows the normal relation between the teeth of the .escapement-wheel and a stepping dog; Figure 7 shows the relation of these parts at the end of a down stroke of a key or at the instant of typeimpactwhere the tooth of the escapement-Wheel has passed to the control of the holding dog and the stepping dog has moved to the position shown to intercept the next advancing tooth. of the escapement-wheel when the rocker is restored; and Figure 8 shows the rocker restored to normal position with the stepping dog positioned between the two teeth of the escapementwheel. The return movement of 4the rocker under the impetus of the driver moves the stepping dog into a position to intercept the tooth 39a of the escapement-wheel before said tooth has shifted from the Figure 7 position, due to the sluggish response of the carriage-motor.

In the Underwood typewriting machine, keys 10 operate levers 11 to operate bell-cranks 12 to swing type-bars 13 about a pivot-wire 14 upwardly and rearwardly against the front face of a platen 15 against the tension of a spring 16, that operates to restore'type-bars upon a pad .17 and the key-levers against a pad 18. The platen 15 is mounted within a carriage having a back bar 19 formed with two lugs 20 arranged to slide on a rear carriage-rail 21. The carriage is drawn in a letter-space direction by a spring-motor 22 having a tape-connection 23 to one of the lugs 2O of the carriage. k, l

Each type-bar is provided with a heel 24 which, inV moving to the dotted position of Figure 1, engages a curved universalvbar 25 forming part of Vthe frame 26 pivotally mounted at the rear upon, pivots 27, carriedby arms 28, forming a frame that is pivotally mounted at 29 to an escapementbracket or frame 30. The bracket 30 Ytakes the form of an invertedrU, providing two legs 31 that are secured to a base-frame 32 in the usual man- The escapement-bracket 30 and base 32, when assembled, form a carriagefeeding standard or unit that is removably secured to the frame of the machine by screws 34. The escapement-frame, when assembled in position, provides an upright structure to support the carriage-feeding elements, including an escapement-wheel 35 and an escapement-dog- 54 supported by the frame 30.

rocker 36. The escapement-wheel 35 is driven in a letter-space direction by aV feed-rack 36a, movable with the carriage to engage with an escapement-pinion 37 looselyV mounted to rotate about the axis of the escapement-wheel and operative to drive said wheel in a one-way direction through pawls 38 mounted upon the wheel and engaging with teeth in the pinion 37.

The tension of the spring-motor 22 tends to draw the carriage leftward in the usual manner, whereby the feed-rack 36L will rotate the pinion 37 and escapement-wheel 35 with one tooth thereof, as 39, pressing against the face of a stepping dog 40, pivotally mounted at 41 to the rocker 36 and provided with the spring 42 operative to draw said dog into a stepping position against a xed stop 43 on the bracket 30. Normally, a tooth 39 is in pressing engagement against the stepping4 dog 40, kbut when the type-bar 13 is raised to the dotted position to vibrate the universal bar 25, an ear 44, formed in the frame 26, engages a screw 45 carried by the rocker, and becomes operative to vibrate the rocker 36 to move the stepping dog out of engagement with the tooth 39, said tooth passing to the control of the holding dog 46 forming a part of the rocker. The escapement-mechanism may also include a check pawl 47, pivotally mounted at 48 upon the rocker and provided with a spring to normally hold the pawl in a position to prevent undue backward rotation of the wheel 35, but not to interfere with the rotation of said wheel in the letter-space direction.

The escapement-rocker 36 may be formed with hubs 49 at each side thereof to receive mitrepointed pins 50 to pivotally support the rocker between the two legs 31 of the escapementbracket. The frame 26 is provided with an ear 51 having a spring 53 connected thereto, effective to draw the frame toward a stationary pin From this description, it will v,be seen that the action of the type-bar vibrates the universal bar 25 against -the tension of the spring 53, engages the screw 45 to vibrate the rocker 36, and vibrates the escapement-dogs through the field of the teeth of the escapement-wheel 35 to effect a letter-spacing :movement of the carriage at each type-'bar movement, which is the standard Underwood construction, and further details may be had in the patent to Helmond, No. 1,411,024, dated March 28, 1922.

The present invention includes an escapementpallet 55 adjustably mounted upon one Ahub 49 of the rocker 36 by means of 'a set screw 56 threaded through a hub 57 of the pallet. The pallet 55 may be formed of sheet metal with the end or" one arm thereof lbent over at right angles to form a stop-face 58, and another arm provides a support for a stud 59 upon which a roll 60 is mounted to project at `right angles to the lane of the pallet. To co-operate with this pallet, a vstar-wheel 61 operates'to alternately en- -one face of each tooth on the wheel 6l has la similar curvature so that the vvibration of the pallet 55 from the positionof Figure 4 to that of Figure 5 will provide for a Ysmooth sliding movement of said stop-face overfthe stationary face of the star-wheel '.teeth. It Will also be noted at Figure 5 that the stop-face 58 .is at the point of releasing a tooth 62 of the wheel 6l and that the roll 60 is in abutting engagement with the face of another tooth 63, so that when the wheel 61 is rotatedin any suitable manner in the direction of the arrow, the tooth 63 will become a driving element to force the roll 60 out of its path and cause a counter-vibration of the pallet and restore the` rocker 36 tc its normal position. 4, that the stop-face 58 bottoms against the Wheel 61 to determine the normal stop position for the rocker 36 under the tension of the spring 42, and that the roll 60 at Figure 5 is in engagement with the tooth 63 approximately at the instant the stop-face 58 releases the tooth 62; hence said roll checks the backward throw of the dog-rocker `under an impulse from the key-actuated universpring tension, the effect of said wheel upon theV pallet 55 will accelerateithe return movement ofv the escapement-rocker, and the abutting screw will project the universal bar 25'to repulse the type-bar from the face of the platen more quickly than the spring 53 could possibly operate. Just how the co-operation of the pallet with the star-wheel 61 affects the carriage-feeding elements is shown at Figures 6, 7v and 8. Figure 6 diagrammatically shows the normal relative positions of two teeth 39 and 39a ,of the vescapeinentheel with the stepping dog 40 and the holding dog 46. From this normal position of Figure 6, the dog-rocker, including the holding dog 46 and the stepping dog 40, is vibrated in the direction of the arrow, which brings the several parts into the positions shown at Figure 7, where holding dog 46 is holding the tooth 39, and the stepping dog has moved forward against the stop 43 to intercept the advancing tooth 392L of the escapement-wheel, the several positions illustrating the relative relation of the several parts at the instant of type impact against the platen face, and when the pallet 55 has been vibrated to the position of Figure 5, where the tooth 62 is about to be released by the stop-face 58 of the pallet and the tooth 63 about to engage the roll 60 to vibrate the pallet 55 and move and shift the holding dog 46 and stepping dog 40 in the direction of the arrow a (Figure 7) to the position of Figure 8, where the tooth 39 has been released by the holding dog 46 and the stepping dog 40 is in position to intercept the tooth 39 and be carried with the tooth against the stop-face 64` which arrests the escapement-wheel 35 at the end cf its letter-spacing movement.

The star-wheel 61 may be adjustably mounted on a driving shaft 65, as by a screw 66, and the shaft provided with bearings in the upper ends of two lugs 67 forming a part of the base of the escapement-support, endwise movement of said shaft being checked by a collar 68 bearing against one of said lugs. The shaft extends to the side frame of the machine where the free end may be provided with a bearing in an upright bracket 69 secured to the frame.

It will further be noted, as at Figurer rFrom. this description it will be seen that the star-wheel 61 is not a constantly rotating element, ibut may be under a spring tension to rotatev in a. fixed direction, andthe rotation thereof being intermittent and determined by the type-bar-actuated escapement-rocker. Such a mode of operation requires suitable means to restore the tension of the star-wheel periodically, as its power is drawnupon through the action of the pallet 55 in allowing the teeth to escape ione at a time.

vemployed and which may be readily attachedto the present mechanism, as by supplying the shaft 65 with a gear 70 at the free end thereof outside the casing, that is in train with an intermediate gear 71, in train with agear 72 secured to the end of acylinder 73 that houses a spring 74. The spring 7.4 operates to turn gears 72, 71 and to rotate the star-wheel in a clockwise direction, and; to wind up said spring 74, the gear72 may be in operative train with a series of intermediate motion-reducing gears and pinions from asource of power which may be an electric motor, indicated as 75. driven self-winding mechanism of this nature of course, requires checking means to prevent the cylinder from unwinding with the spring, and the starting and stopping of the motor may be automatically controlled by the spring when it reaches certain points,these control features being fully set forth in said Pitman patent.

The mechanism has been described as being co-operative with a type-bar-actuated universal bar, but it is just as essential that other keys, like the space-bar, shall be operative to quickly effect a carriage-feeding movement of the carriage. To this end, the space-bar 76 is provided, in the usual manner, with levers 77 operative to rock a shaft 78, carrying an arm 79 operative to vibrate an arm 80 fixed to an extension of the frame 28. The depression of the space-bar 76 rocks the arm 80 and the frame 28 about its pivot 29 to draw the universal bar-frame 26 rearwardly until the ear 44 thereon engages the screw. 45 of the escapement-rocker when the rocker is vibrated in a manner similar to that already described when actuated by the type-bar.

It will be noted at Figure 6 that the usual bevel face, indicated at 81 in dottedlines, is superseded by a at face and that the tooth 39, in passing from the control of the stepping dog 40, will have a very slight clearance drop, which is the usual practice. It will be furthernoted that the interval of time between the release of the tooth 62 by the stop-face 58 and the driving engagement of the tooth 63 against the roll 60 is nil, and that the effect of the star-wheel upon the pallet 55 is practically instantaneous and provides a restoring means more effective than any bevel-dog structure to quicklyeffect a letter-space movement after a type-impact and to simultaneously provide a repulsing means vto more quickly get the returning type-bar out of the path of an advancing type-bar, both features being conducive to greatly increase the speed of manipulation of the machine. y

A motory Variations maybe resorted to Within the scope of the invention, and portions of the improvements may be used without others.

Y driver to forciblyrestore the rocker for a letterspacing movement.

2.*In a typewriting machine having keys and typing elements driven thereby, a. power-'driven carriage and a carriage-feeding mechanism operable by the keys to letter-space the carriage, a power-driven rotary driver, and means normally operative to restrain the rotation of the driver, said means being movable' by the carriage-feeding elements to become automatically effective to release the driver after each typing movement, said carriage-feeding elements being then actuable by the driver to accelerate the letter-space feed o the carriage and the return .of the operated key to normal position.

3. Impulse return mechanism for a type bar comprising a bracket, a rocker arm pivoted in the bracket, a pallet adjustably pivoted on the rocker arm, a motor operated escapement Wheel pivoted in the bracket and cooperative With the pallet to periodically give an impulse thereto and connections between the rocker arm and the type bar to impart the impulses of the pallet to the bar. Y

e. Mechanism for imparting a return impulse to a type-bar comprising a motor operated escapement Wheel, a rocker arm having check and stepping pavvls carried by said arm to control said escapement wheel, an oscillatable pallet coaxial and rigid with the rocker arm, a motor operated escapement Wheel having teeth rotatable in a plane parallel to the plane of movement of the oscillatable pallet, one side only of each tooth of the second-mentioned escapement wheel being operative to give an impulse to the pallet and rocker arm, the stopping face of the same side of each tooth being concentric with the pallet and transmitting means from the rocker arm to the type bar. i Y

5. Mechanism for giving a return impulse to'a type-bar comprising a universal bar movable to give an impulse to the type-bar, a rocker arm connected to said universal bar, an oscillatable pallet having' a stop prong and an impulse prong rigidly connected to the 'rocker arm, a motor operated escapement Wheel having its axis perpendicular to the plane of movement of the pallet and also having one side of each of its teeth inclined to give an impulse to the impulse prong of the pallet, the same side of each tooth being cooperative With the stop prong of the pallet to stop and temporarily hold the escapement Wheel stationary and connections between the rocker arm and the universal bar to transmit the impulse to the type-bar.

6i A return impulse mechanism for a type-bar comprising a toothed escapement Wheel and a motor therefor, a rocker arm having escapement pavvls thereon to control said Wheel, the contact- 'insT faces of the pavvls and teeth on the wheel being in the same plane While in contact, a pallet rigid with the rocker arm, a second escapement wheel having teeth cooperative with the pallet and a motor to operate said second escapement wheel, one of the pallet prongs being cooperative with one side of each tooth of the Wheel to stop and temporarily hold thevvheel stationary and then release the same, and the same side of the tooth being operative on the other prong of the pallet to give an impulse to the same, and connections between the rocker arm and type bar to transmit the impulse from the impulse prong of the pallet to the type-bar.

BURNHAM C. STICKNEY.`

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