US1928561A - Automatic ribbon reversing mechanism for typewriters - Google Patents

Description

Sept 26, 1 933. M. GRANDJEAN AUTOMATIC RIBBON REVERSING MECHANISM FOR TYPEWRITERS 3 Sheets-Sheet 1 Filed Sept. 11, 1928 Sept. 26, 1933'. M. GRANDJEAN AUTOMATIC RIBBON REVERSING MECHANISM FOR TYPEWRITERS Filed Sept. 11, 1928 lll 3 Sheets-Sheet 3 77% ran'eqm Patented Sept. 1933 1,928,561 i AUTOMATIC RIBBON anvEnsiNG MECHA- FOR TYPEWRITERS Marc-'Grandjean, Paris France Application vSeptember 11, 1928," Seriat No."

7 305,299, and in ll rance Octcber 4, 1928;;

3 Claims. (01. 197-1-165) I havefiled an application inFrance Oct. 4,

The invention has for its object a device for automatically reversing the, inking ribbon longid tudinal motion in stenographic machines, said ribbon winding ina known way on two reels fitted ontwo hubs rigid with two worm wheels operated alternately by two worm wheels.

The invention essentially consistsin that the reversal is obtained by means of a device actuated by a spring previously tensioned by pressing upon a knob and held in tensioned condition until it is released by the actionof an abutment provided at each end of the ribbon, this spring engaging i, .15 one of the worms with the respective toothed wheeland disengaging the other.

Aform of carrying out thesubject-matter of the :invention is illustrated, by way of example, in the accompanying drawings, in which:

Fig. l is a top plan view. Fig.2, is a rear View.

Fig 3 isan underside-plan view. I h Fig.4 alongitudinal section through the middlepoition; 1 v

Figs. 5 to 7 diagrammatically illustrate the operation of the reversing device.

; ends of a shaft 38 or in one piece withthe latter. The-shaft 38 can rotate in bearings .44 (Fig.3)

; rigid with aframeelii pivoted ona vertical 46, on thelower side oftheframe (Fig. 4) This I shaft 46 carriesa slotted head 46a and is secured at the top in amernber 46b secured on the frame -33. The frame is guided, on theone hand, he-

tween the head 46m: the'shaft 46 and the lower face of theframe 3 3 and, onlthe other hand, at -.thefree end of the frame, by a tongue 46c sliding between. the lower face ofthe frame and a guide 47 secured on this frame. The arrangementis such that, by. oscillationof the frame 45, towards therightor towards the left, oneor the other of the worms engages with the corresponding worm ;,w -&;

Between the bearings 44; of the frame, the shaft 38 carries a pawl and ratchet-device connected shaft to: the universal bar of the machine, so that upon each depression of thekeys the shaft carrying the worms 3'? rotatesthrough a fraction'of a revolution. As one or the other of the, worms is always in engagement with the corresponding wheel 34b,

the latter as well as its ribbon-carrying spool 34 mustfollow the intermittent rotationof the shaft i 38and the ribbon itself is moved forward, asin all typewriting machines. c

' The above pawl and ratchet device is composed [Figs. 3 andld) of a "plate 39 loosely mounted on a hub 38a rigid with the shaft 38., 'Iiheconnection between the plate and the hub in one direction onlyis obtained by p'awls' 40"mounted on the plate. and engaging with the teeth of a ratchet 42 under the action of springs 41. The

plate 39 is corinectedfto the universal bar of v the machine by a system of levers andlinks 43 partially illustrated.

According tothe invention, the reversal of the movement of the inking ribbon must be obtained by'an automatic oscillation of the frame'45 when the ribbon has-entirelyunwound in one'direction .or the other... By automatic operation, the inventor means'that the operator presses upon a knob immediately after reversal, or in anycase,

before. the end of the unwindingiof the ribbon '80 in the new direction, and thus'sets the reversing device which .is' held in a stretched condition until the ribbon has entirely unwound. As' 'soon as the ribbon comes to its end, the reversing device is released by the action of an abutment and causes the frame 45' torock, so thatthe worm 3'7 which was freeup to this moment, engages with'the teeth of the correspondingwheel 342).

the drawings, theQknob which is to be pressed upon by the operator isindicatedat 51. It canslide and rotate in a fixed guide '51!) mounted on the member 46?). On the side of. this member, the guide has w inclines 51c, (Figs. 4 and 7) forming an angle the apex of which is downwardly directed and'is exactlysituat'ed inthe axis of the machine. On the opposite side,

the guide 5112 is obliquely cut. at itslower end,

and, at this place, a circular groove 5101 is pro- ;vided about the knob 51.' The latter is moreover; extended...downwardly in a tail piece '5le 1 against whichbears a, spring 52 secured to the framed? andtendingto cause the knob to rise when the latter has been pressed upon by the operator. 7 c

But the knob-is held in its lowered. position by .1 a pawl and lratchet device, 7 constituted for instance by. aims 58 which entersthe groove 51d and remains therein until the device is tripped at the end of the unwinding of the ribbon. Theknob 51 carries-a claw 51c which projects L f laterally and is returned exactly in the median plane of the machine by one of the inclines 510 when the operator presses upon the knob, but, when the knob rises under the action of the spring 52, this claw engages with a reversing member 50, rocking on a stud a and in which is provideda heart-shaped recess,so that for successive rising'movementsof the knob under the action of the spring 52, this reversingmember alternately rocks in two opposite directions. This reversing member, provided with a point at its upper part, is heldin each position by a spring 60, having a V-shaped section, secured on the upper side of the member 46b and cooperating with the point of the reversing member. The latter has, at its lower end, a fork piece 49, between the branches of which extends-a resilient tongue secured on the rocking frame 45. The rocking movement of the reversing member 50, produced under the action ,of the spring 52 through the medium of the knob 51 ahdof "the clawf51a, is therefore transmitted; by the said tongue 48, to the" frame 45 and, by'the latter, to the worms. l

The reversing devicecomprising the knob 51,

the fixed inclines 51c and the reversing member 50cooperatingwith thespring 60. Its operation has been diagrammatically illustrated in Figs. 5, 6 and 7. These figures only show the essential parts, seen from theinner side of the machine (from the left in Fig. 4) The path followed by the claw 51a is indicated by small arrows.

In Fig. 5, it has been assumed that the operator has previously pressed upon'the knob 51 and has, from this fact, tensioned the spring 52. The claw 51a has therefore been'moved to the bottom of the angle formed by the inclines'51c, that is to say in the position I.. j y I e As soon as the knob 51is released by the rod 58 and that the spring'52 causes it to rise, the 'claw is successively moved to the positions II,

III"and IV (Figs; 5 and 6). The upper point of the reversing member "50 (Fig. 5) is located to the left'of thespring 60, so that the point 50b of the heart-shaped recess is located to the right of the vertical axis of the machine. In the position II, the claw therefore strikes against the lefthand side of thepoint 50b and slides on this side to the bottom of the left-hand notch towards the position DI, this of course having for effect to cause the knob 51 to rotate about its axis. When passing from position III to position IV, the claw 51a. produces the oscillation'of the reversing member-on itsstud 50a in the direction of the arrow, and'the upper point of the reversing member passes from the lefthand side to theright-hand side of'the'sp'ring 60, and the inner point 502) passes from right to left (Fig. 6). But, from this fact, thetongue 48 extending between the branches of the fork piece 49, is also moved, the frame 45 pivots about its shaft '46, and the direction of movement of the ribbon isthus reversed.

All the parts of the reversing device remain in this position until the operator again tensions the spring 52 by pressing upon the knob 51'. The claw 51a therefore first moves to the position V (Fig.5) andslides on one of the inclines 510 which returns it to they initial position VI by causing'theknob 51' to rotate. The claw remains 'in this position until the reversing device is again released. at the, end of theunwinding of the ribbon. The knob risesv under the action ofthe spring-52; so that the claw 51a first comes to the position VILstrikes against the right-hand side of the point 501), slides on this side towards the position VIII to the bottom of the right-hand notch and passes to the position IX (Fig. 7) by causing the reversing member to rock. During this time, the upper point of the reversing member again moves to the left-hand side, and the inner point, 5012, as well as the fork piece 49 with the tongue 48, moves again to the right-hand side. a

When the spring 52 is again tensioned, the claw 51a will first move to the position X and will slide on the incline 510 which will return it to the position I.

The device serving to actuate the tripping rod '58 can be of any type. As shown in Fig. 4, this rod constitutes an element of a parallel motion 53, 54, 57, the side 54 of which is rigid with the shaft 55. A spring 58a tends to push the rod in the circular groove of the knob.

The shaft 55 carries, at each end, a lever 56, which is located in the path of an abutment 59 provided at each end of the inking ribbon. When the unwinding of the ribbon is at its end, this abutment engages with the corresponding lever 56 and causes it to rock; Through the medium of the parallel motion 53, 54, 5'7, the rod 58 is then' removed from the groove of the knob and the latter rises under the action of the spring 52.

I claim: 1. In a device for automatically reversing the inking ribbon longitudinal motion in stemgraphic machines, the combination of two reels upon which the said ribbon winds itself, two

ibs

hubs on which are fitted the reels, two worm wheels rigid with said hubs, two worm drives said reversalmeans when the ribbon is almost 7 entirely wound ofi.

2. In a device for automatically reversing the inking ribbon longitudinal motion of stemgraphic machines, the combination of two reels upon which the said ribbon winds itself, two hubs on which are; fitted the reels, two worm wheels.

rigid with said hubs, two worm drives'adapted to operate alternatively the said worm wheels, a

shaft carrying at each of its ends one of the said worms, a' frame carrying the said shaft and adapted to oscillate transversely towards the right and towards the left, reversing means adapted'to cause the said frame to rock in the right or leftv direction, alternatively, a spring adapted to actuate the said reversing means, a plunger pressed by the operat'or in order to tension the said spring, means adaptedto maintain the said spring in tensioned position, and abutments provided at the ends of the inking ribbon of the machine, the said abutments being adapted to act upon the said reversing means when the ribbon is almost completely wound off.

3. In a device for automatically reversing the inking ribbon longitudinal motion in stemgraphic machines, the combination of two reels upon which thesaid ribbon winds itself, two hubs on which are fittedthe reels, two worm wheels rigid withsaidhubs, two worm drives adapted to operate alternately the said worm wheels, a shaft carrying at each end one of the said worms, a frame carrying the said shaft and adapted to rock transverselyto the right or to the left so that one or the other of the worm drives alternatively engage one of the worm,

wheels, a reversing device provided with a recess in the form of a heart and an external point, a

horizontal spindle on which the said reversing means rocks, a spring for laterallyrepelling the upper point of the said reversing means, a fork piece on the said reversing means, a tongue secured to the said frame and so arranged as to enter between the branchesof the said fork, a

disposed at the ends of the inking ribbon of the machine, said abutments being adapted to act upon the said means when the ribbon is almost entirely wound 01f.

MARC GRANDJEAN.

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