US1855342A - Typewriting machine - Google Patents

Description

April 26, 1932. w. A. DoBsoN TYPEWRITING MACHINE Filed June 19, 1929 2 Sheets*Sheet /m/enfar t myV/,MM

April 2s, 1932. w. A. DOBSON 1,855,342

TYPEWRITING MACHINE Filed June 19, 1929 2 sheets-'sheet 2 WwW/K7 Y I, Alf/orne Patented Apr. 26, 1932 UNITE STTES PTENT @FFICE WILLIAM A. DOBSON, 0F IBRIDGEPORT, CONNECTICUT, ASSIGNOR TO 'UNDERWOOD ELLIOTT FISHER- CIVIIPANY, OF NEW YORK, N. Y., A CORPORATION 0F DELAWARE l TYPEWRITIN G MACHINE Application filed .Tune 19,

This invention relates to the automatic ribbon-reversing mechanism of typewriting machines.

One of the aims-of the invention is to meet the requirements of portable typewriter mechanism for simplicity, compactness, inexpensiveness, lightness and reliability. The

invention, however, is also applicable to typewriters of standard size.

It is a feature of the invention to employ simple means for continuing the'longitudinal movement of the ribbon during the priming of the automatic reverser, this being necessary because, if the ribbon should stand still while receiving repeated type-impressions, it would become depleted of ink at that spot, and a hole would soon wear in the ribbon. It is therefore an aim of the invention to employ means for gradually priming the ribbon-reversing device, as the ribbon continues its advance, during a succession of type-key operations in any of the various methods known in this art, as for example, in the manner disclosed in the patent to Stickney 1,075,996, in'which a pawl, which is reciprocated by the key-strokes, co-operates with a ratchet-wheel to gradually prime a ribbon-reversing cam.

A purpose of the invention is to provide a gradual priming means without thenecessity of using followers to rest upon the ribbon coiled upon the spools as in said Stickney Patent, for initiating movement of automatic reversing mechanism.

A portable machine is often set down with a thump,y on theback end, opposite the handle end, opposite the handle end. This is liable to cause the swinging arms or ribbon-guides carrying the pawls to swing and rotate the ratchet-wheels thereby causing both the lefthand and the right-hand ratchet-wheels to be accidentally rotated into ribb oli-reversing positions and lock the machine.

In order to overcome this difficulty, there is provided a connection from the usual carriage-centering lock, to hold the pawl against any possible faulty action when the cover of the machine is in position. Before putting the cover on the machine, the carriage is always centered; a hook at the'side of the ma- 1929. Serial No. 372,063.

chine being lifted to catch in the carriage as theoperator releases it and moves it to the left. The lifting of this hook operates to swing a lever to a point in back of the pawlcarrying arm, so that this arm cannot be swung.

@ther features and advantages will hereinafter appear.

In the accompanying drawings,

Figure l isaJ fragmentary sectional view, front toV rear, through an Underwood portable typewriting machine with my invention applied thereto.

Figure 2 is a fragmentary sectional view through the mechanism for operating the right-hand spool in a plane approximately at a right angle to Figure l, certain of the parts being shown in elevation.

Figure 3 is a fragmentary view of the reversing mechanism in perspective.

Figure i is a fragmentary view of the carriage-locking device `also showing a retaining means for holding .the actuating lever for the reversing mechanism when the machine is to be transported.

Figure 5 is a plan view of the ribbon-spools with operating and reversing mechanism showing the left-hand spool being operated and the right-hand spool thrown out of operation.

Figure 6 is a fragmentary perspective view of the right-hand spool and associated ribbon operating and reversing mechanism of this invention.

Figure 7 is a fragmentary perspective view of the reversing mechanism of this invention, showing the button on the ribbon engaging the lever which puts the reversing mechanism in condition for operation by the movement of the keys on the keyboard. The position of the parts is such that the reversing lever is just beingengaged by the cam.

Figure 8 is a fragmentary perspective view of the ribbon reversing and feeding mechanism of this invention showing the parts in position where the reversal takes place.

Figure 9 is a fragmentary elevation, partly in section, of the ribbon-reversing device showing-its attachment to the frame of a machine.

The invention embodied in this application is shown in the accompanying drawings as being attached to a portable typewriting machine, in which keys 10 are fastened on key-levers 11, pivoted at 12 on a frame 13. Type-bars 14 are operated by a bell-crank 15 with a slotted arm 16 engaging a pin 17 on the key-levers 11.

Rear arm 18 of the bell-crank lever is connected by a link 19 to the lower end 20 of a type-bar 14 which is fulcrumed at 21. The type strikes on a platen 22 pivoted in a carriage 24 by means of a shaft 23. The keylever is normally pressed upward by a coilspring 25. A universal bar 26 extends across the machine under the key-levers 11 and is operated each time a key is depressed, after which it is returned to its normal position by a coil-spring 28. The universal bar is pivoted at 27 and is limited in its upward movement by a rod 29. The usual oscillator 30 holds the ribbon 31 and moves it into and out of position as a key 10 is struck and released. The ribbon 31 is wound on the usual spool 32. An arm 47 attached to the universal-bar is connected by a link 46 to a rocker-arm 44 which is pivoted on a shouldered screw minates at a wrist-member 76 having a slot 77 embracing a wrist-pin 42 fastened in an oscillating member 41. This member 41 has a spring-operated pawl 40 pivoted thereto and bent at right angles to the member 41 so as to engage the teeth of a ratchet-wheel 35 mounted on a pivot 33, on which the spool 32 is held by a screw-cap 34. This pawl 40 is pressed toward the ratchet-wheel by the usual coilspring. It is operated by spring 28, which returns the universal-bar train, on the up stroke of the key.

A sleeve 37 is passed over the pivot 33 and secured in a housing 74 which is made of rectangular tubing. This housing support-s all of the ribbon-spool-operating mechanism and is secured to the shift frame 56SL of the typewriter by screws 78. The sleeve 37 has a cam-plate 36 rigidly attached thereto.

Pivoted to the shift frame 56n is a detentawl 48 which engages the teeth of the ratchet-wheel 35 and holds it so that its action cannot reverse by reason of the friction of the operating pawl 40.

The cam-plate 36 is interposed between the oscillating member 4l and the ratchetwheel 35 in order to throw out the operating and detent pawls 40 and 48 simultaneously. This cam-plate is shaped substantially as shown in Figure 5 of the drawings.

The sleeve 37 attached to the cam-plate 36 has amember 38 clamped to its lower end so that the two will operate together, and yet permit adjustment of one relative to the other so as to properly engage or disengage the pawls from the ratchet-wheels when reversal of the ribbon-mechanism is required. The member 38 has a rearwardly-disposed 75, and terarm 39 which is in position to be engaged by a vertically-disposed cam-surface 60 attached to a cam-plate 59.

A housing 56 of rectangular tubing is attached to the shift frame 56 of the machine by screws 57 and 58. Pivoted in this housing is a shaft 55 on which is rigidly mounted the cam-plate 59 by means of a hub 93 and set-screw 61. Attached to the inner part of the housing and bearing against said hub iS a spring 62, which produces friction so as to prevent overthrow.

Attached to the outer end of the shaft 55, on the opposite side of the housing from the cam-plate, is a ratchet-wheel 53. This ratchet-wheel has teeth 52 cut regularly in the greater portion of its circumference, but at one point 54 there is a section removed to the depth of the teeth, forming a gap. The cam-plate 59 has one section of its circumference formed with the laterally-deiiected cam-surface 6() through which the camming action is produced on the rear arm 39 of thel member 38. The ratchet-wheel 53 is operated by a lever 49 and pawl 51 which engages the teeth 52 of said wheel, and is held against the wheel by means of a coil-spring 50. The lever 49 is pivoted on the rockerarm 44 and is prevented from overthrow during action by alaterally-extending lip 79 on the end of the lever 49 and a lug 80 on the rocker-arm 44. The lateral swing of the lever 49 is prevented by an upwardly-extending lug 72.

Pivoted to the frame at the side of the ribbon-spool is an arm or lever 63 held in place by and rotated on a shouldered screw 64. This arm or lever has an upwardly-extending portion 65 with a slot 66 for the purpose of guiding the ribbon. The lever 63 is held normally in close proximity to a spool-cup 81 by means of a coil-spring 73 fastened at one end to the arm or lever and at its other end to the frame of the machine. Loosely pivoted to the middle section of this arm or lever on a pin 68 is a dog or pawl 69 having its downwardly-bent end 7 O engaging with the teeth of the ratchet-wheel 53. This pawl has a downwardly-extending lug 82 to prevent lateral swing of the same during operation.

By reference to Figure 1 it will be seen that the pin 68 allows freedom of movement of the pawl 69 so that it will engage the wheel by the action of gravity.

From this description it will be seen that when the rocker-arm 44 moves backward and forward, the pawl 51 engages with the teeth 52 of the ratchet-wheel. and moves said wheel one notch for each action of a type-bar. This continues until the wheel has made one revolution and comes to the cut-out sector 54 when the pawl 51 simply oscillates back and forth without producing any movement of the ratchet-wheel 53. The cam-member is so s... .LUL

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vmechanism for the spools.

disposed on the shaft that when this is the case the camming action is ready to begin upon a slight movement of the wheel so as to engage the pawl 51 with the rst tooth 1 52 in the ratchet-wheel 53. lt will be seen that by the relative size of the parts, as shown in Figure 1 of thedrawings, this camming action of the reversing mechanism is not completed until three or four keys have been struck. The power required for the reversal of the mechanism is therefore very slight, and not noticeable to the operator, which is very important in this type of machine.

In order to partially rotate this ratchetwheel 53, a mechanism is provided to give the wheel an initial movement by the-continued movement of the ribbon. This is accomplished by fastening a button 67 near the end of the ribbon, which passes through the slot 66 in the end 65 of the lever 6,3, and as it is paid out from the spool the button engages said end, pulling the lever away from the spool-cup, and by reason oi' the engagement of the pawl 69 with the teeth 52 of the ratchet-wheel 53, it gives the initial movement necessary upon operation of the neXt two or three type-bars. The following typeactions complete the camming action of the cam-plate 59, throwing the member 38 in a lateral direction, which, through a link 83, operates a similar mechanism on the opposite spool to throw it out of action and throw the operating mechanism on this spool into action, which starts to rewind the ribbon on the spool, and the coil-spring 73 returns the lever or arm 63 to its normal position ready for the next reversal action.

As is readily seen from Figure 5 of the drawings, cam-plates 36' on opposite spools are operated so as to alternately put them in effective or ineiicective position, thereby placing the operating pawls 40 ofthe ribbonmechanism on each spool alternately in and out of position to drive the ribbon-winding The principal operation or" the drive-pawl mechanism may be substantially the same as set forth in patentto Lee S. Burridge, deceased, 1,249,022, dated December 4, 1917.

The link 83 is made of still wire bent in a substantially U-shapedform to operatively connect the two members 38 of the reversing mechanism. The U-shape disposes the connecting link so it is housed within the machine and between the operating parts, whichV prevents interference of the necessary movements. To the end that the feed mechanism may be reversed, at any time desired, a forwardly-extending lever 84, pivoted at 85 on the front portion of the machine, has a rearwardly-extending slotted arm 86 to engage the link 83. The forwardly-extending portion of the lever 84 passes through a segmental slot in the cover-plate 87 of the machine tf'i for the purpose of operating it readily Vfrom the front. The construction and operation of this lever may be substantially the samey as set forth in the co-pending application of George H. Meyers, 282,303, led June 2, 1928 (now Patent No. 1,808,505, dated June 2, 1931 The depression of a key 10 vibrates the universal bar 26, arm 47, link 46, rocker-arm 44 and member 41, to draw the pawl 40 idly over the teeth of one ratchet-wheel 35, and, upon the release of the key, the spring 28 will restore these parts and drive the pawl 40 to turn the ratchet-wheel a ribbon-spoolt'eeding distance. At each successive action of the keys the ribbon is further wound until itreaches near the end on the spool opposite, whose mechanism is inoperative. At this time, the button or eyelet 67 on the ribbon 31 Vstrikes the upwardly-bent end 65 of the lever 63 and at each successive action, the button pulls this lever further out and away from the spool-cup, dragging with it the ratchet-wheel 53 by means of the pawl 69. Since this action is suliicient to bring the pawl 51 into engagement with the first tooth of the ratchet-wheel next to the notch 54 where it has been inefl'ectively operating, the actionof the next type-bar starts to rotate this wheel 53 and begins the camming action on the arm 39 of the reversing member 38. Upon each further successive action the cam pushes the lever further until finally the cam-plate 36 is thrown into position to render the operating pawl 40 of the full ribbonspool ineilective, and at the same time, by the action of the interposed link 83, the cam-plate which prevents operation of the ribbon-feed mechanism on the other spool is thrown out of position and permits the pawls 40 and 48 to engage their ratchet-wheel 35, thus rewinding the ribbon on the empty spool. By this action the power required to produce the complete reversal is divided between the down and the up stroke of the key and makes it imperceptible to the operator, while at the same time there is no undue strain put upon the ribbon or any of the operating mechamsm.

In order to hold the arms or levers 63 in normal position for operation when the typewriting machine is tilted in a vertical position, the ends 88 projecting beyond the fulcrum-screws 64 are slightly weighted, either by extending them as shown in Figures 4 and 5, or applying a weight in any other manner to produce the same result. Sulicient weight should be added so that the action of gravity, together with the pull of the coil-spring 7 3, will prevent the` lever 63 from being thrown out of normal position which would tend to set the reversing mechanism into operation on both sides of the machine at the same time. This is likely to happen when the typewriter is carried in acase, and is set down forcibly on the end opposite ioo the handle. In order to `positively hold the lever or arm 63 on the left-hand side of the machine, an additional lever 89 is pivoted on the frame of the machine and is formed in the shape of a bell-crank, pivoted at 95, the upper arm 90 of Which has a forwardly-projecting lip to engage a lug 91 on the lever 63. The other end 92 has a slot 96 cut in it in order to fit into the notch 97 in the edge of a carriage-positioning lever 94, as shown in Figures 1 and 4, and substantially such as shown in the patent to Campbell 1,677,170 dated July 17, 1928, so that when the carriage is in position for carrying in a case, the lever is moved upward to engage the hook 98 With the end 99 of the carriage 24 and hold said carriage, thereby automatically engaging the forward end of the arm 90 With Vthe lug 91 on the lever 63.

This mechanism just described Will prevent the levers 63 from being thrown backward out of position if the typewriter is set down With a jar While being carried in a case, and consequently would prevent the levers from setting the reversing mechanism into operation, which might cause both ribbon-Winding devices to operate at once and lock the machine or possibly cause injury to the same.

It will be understood that While the mechanism has been shown in this particular case as applied to a portable typewriting machine, it can be readily employed in connection with any other form of typewriter, adding machine or any other allied device employing a continuous ribbon for making records, by making certain simple modications such as any ordinary mechanic is capable of suggestmg.

It will be readily understood that the weighted ends 88 of the lever-s or arms 63 may be omitted if desired.

The carriage 24 runs on the usual ballbearings 100 and 101, driven by the usual spring-drum 102.

The invention is not limited to the exact details of construction shown and described; and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a ribbon-eed-reversing mechanism for typewriting machines, the combination of a ribbon-spool, means for rotating the same from the action of the type-bars, means for rendering said rotating means ineective, a reciprocating member oscillated at each typestroke, a ratchet on said member, a ratchet- Wheel with an inoperative section mounted so as to be engaged by said ratchet, means brought into play by the unwinding of the ribbon to move said ratchet-Wheel to an eective position, and means operatedby said ratchet-Wheel to reverse the operation of the spool-rotating means.

2. In a ribbon-feed-reversing mechanism, the combination of a spool, means for rotating the spool, means to render said rotating means ineffective, a ratchet-Wheel vvith several teeth removed to render the same normally ineffective, means operated by the un- Winding of the ribbon for putting the ratchet-Wheel in condition for operation, means for operating the ratchet-Wheel, and means connected with said ratchet-Wheel to reverse the operation of the spool-rotating means.

3. In a ribbon-eed-reversing mechanism, the combination of a spool, means for rotating the spool, mea-ns to render said rotating means ineffective, a ratchet-Wheel with several teeth removed to render the same normally inetective, means operated by the un- Winding of the ribbon for putting the ratchet-Wheel in condition for operation, means for operating the ratchet-Wheel, a cam-disk mounted coaxially with said ratchet-Wheel, and means operated by said disk for reversing the operation of the spool-rotating means.

4. In a ribbon-eed-reversing mechanism, the combination of a spool, means for rotating the spool, means to render said rotating means ineffective, a ratchet-Wheel With several teeth removed to render the same normally ineective, means operated by the un- Winding of the ribbon Jfor putting the ratchet-Wheel in condition for operation, means for operating the ratchet-Wheel, a cam-disk mounted coaXially With said ratchet-Wheel, and a lever operated by said cam-disk for reversing the operation of the spool-rotating means.

5. In a ribbon-feed-reversing mechanism, the combination of a spool, operating means including a means for rotating the spool, means to render said spool-rotating means ineEective, a ratchet-Wheel with a notch Where the operating means becomes ineffective, means to operate said ratchet-Wheel, means operated by the unwinding of the ribbon for putting the ratchet-Wheel in condition for operation, and means connected With said ratchet-Wheel for reversing the spoolrotating means.

6. In a ribbon-eed-reversing mechanism, the combination of a spool, operating means including a means for rotating the spool, means to render said spool-rotating means ineffective, a ratchet-Wheel With a notch Where the operating means becomes ineffective, a pavvl connected With said operating means and engaging said ratchet-Wheel, means operated by the unwinding or' the ribbon to put the ratchet-Wheel in condition for operation, and means connected with said ratchet-Wheel for reversing the spool-rotating means.

7. In a ribbon-eed-reversing mechanism.v the combination of a spool, operating means including a means for rotating the spool, means to render said spool-rotating means ineiective, a ratchet-Wheel With a notch Where the operating means becomes ineffective, a paWl connected With said operating means and engaging said ratchet-Wheel, a lever operated by the unwinding of the ribbon, a second paWl engaging the ratchet- Wheel and connected to said lever for moving the ratchet-Wheel into position for operation by the paWl connected to the operating means, and means connected with said ratchet-Wheel for reversing the spool-rotating means.

8. In a ribbon-feed-reversing mechanism, the combination of a spool, operating means including a means for rotating the spool, means to render said spool-rotating means inedective, a ratchet-Wheel With a notch Where the operating means becomes ineffective, a paWl connected with said operating means and engaging said ratchet-Wheel, a lever operated by the unwinding of the ribbon, a second paWl engaging the ratchet- Wheel and connected to said lever for moving the ratchet-Wheel into position for operation by the paWl connected to the operating means, a cam operated by said ratchet-Wheel, and means operated by said cam for reversing the operation of the spool-rotating means.

9L In a ribbon-feed-reversing mechanism, the combination of a spool, operating means including a means for rotating the spool, means to render said spool-rotating means ineffective, a ratchet-Wheel with a notch Where the operating means becomes ineective, a pawl connected with said operating means and engaging said ratchet-Wheel, a lever operated by the unWinding of the ribbon, a second paWl engaging the ratchet- Wheel and connected to said lever for moving the ratchet-Wheel into position for operation by the paWl connected to the operating means, a cam connected coaXially With said ratchet- Wheel, and means operated by said cam for reversing the operation of the spool-rotating means.

10. In a ribbon-feed-reversing mechanism, the combination of a spool, operating means including a means for rotating the spool, means to render said spool-rotating means ineective, a ratchet-Wheel With a notch Where the operating means becomes ineffective, a pavvl connected With said'operating means and engaging said ratchet-Wheel, a lever operated by the unwinding of the ribbon, a second pawl loosely engaging the ratchet-Wheel and connected to said lever for moving the ratchet-Wheel into position for operation by the paWl connected to the operating means, and means connected With said ratchet-Wheel for reversing the spool-rotating means.

11. In a ribbon-feed-reversing mechanism, the combination of a spool, operating means including a means for rotating the spool,

means to render said spool-rotating means ineffective, a ratchet-Wheel With a Vnotch Where the operating means becomes ineffestive, a shaft on Which said ratchet-Wheel is mounted, a housing for supporting said shaft, a cam mounted on said shaft androtated by the ratchet-Wheel, means for rotating said ratchet-Wheel, means operated by the unwinding of the ribbon for putting the ratchet-Wheel into condition for operation, and means connected With'said ratchet-Wheel for reversing the spool-rotating means.

l2. In a ribbon-feed-reversing mechanism, the combination of a housing attached to the frame of a typewriting machine, a shaft mounted in said housing, a ratchet-Wheel With a notch in its periphery mountedon said shaft, a cam mounted'rigidly on said shaft, an operating lever actuated by the type-bars, a spring-pressed pa-Wl connected to said operating lever and engaging said ratchet- Wheel, means operated by the unwinding of the ribbon to rotate the ratchet-Wheel into position for operation by the pawl, and means operated by the cam for reversing the ribbonfeeding mechanism.

13. In a ribbon-feed-'reversing mechanism, the combination of a housing attached to the frame of a typewriting machine, a shaft mounted in saidhousing, a ratchet-Wheel with a notch in its periphery mounted on said shaft, a cam mounted rigidly on said shaft, an operating lever actuated by the type-bars, a spring-pressed paWl connected to said operating lever and engaging said ratchet-Wheel, a second paWl for engaging said ratchet-Wheel to move it into operative position, a lever to which said paWl is connected, and means operated by the unwinding of the ribbon for moving said lever.

141-. In a ribbon-feed-reversing mechanism, the combination of a housing to be attached to the frame of a typewriting machine, a shaft mounted in said housing, a ratchet- Wheel With a notch in its periphery attached to said shaft, a cam-disk rigidly attached concentric to said ratchet-Wheel, an operating lever actuated by the type-bars, a springpressed paWl connected to said operating lever and engaging the bottom of the ratchet- Wheel, a second paWl engaging the top of the ratchet-Wheel, means operated by the un- Winding of the ribbon for actuating said second paWl to move the ratchet-Wheel in position for operation by the operating lever, and means operated by said cam-disk for reversing the ribbon-feeding mechanism.

l5. In a ribbon-feed-reversing mechanism for a typewriting machine, the combination of a ribbon-spool, means for rotating said spool, means for rendering said rotating means ineffective, a reciprocating member oscillated at each type-stroke, a ratchet-Wheel with an inoperative section, a spring-pressed paWl on said reciprocating member and engaging said ratchet-wheel for its operation, a cam-disk mounted rigidly and coaxially with said ratchet-wheel, means brought into play by the unwinding of the ribbon to move the ratchet-wheel into position for operation, and

means operated by said cam-disk for reversingthe feed of the ribbon.

16. The combination of a ribbon-spool, a ratchet-wheel for operating said saool, a reciprocating lever pivoted on the rame of a typewriting machine, a spring-pressed pawl and detent pivoted on the one end of the arm for engaging the ratchet-wheel, a link, a bell-crank and a universal bar connected together for operating said lever, a housing fastened to the frame of the machine, a shaft mounted in said housing, a ratchet-wheel with an inoperative portion mounted on said shaft, a spring-pressed pawl pivotally mounted on the reciprocating lever and engaging the teeth of said last-named ratchet-wheel, a cam-disk rigidly mounted on the shaft, a lever pivotally mounted on the frame, a ribbon-guide on the end of the last-named lever, a pawl loosely pivoted on said lever, means attached to the ribbon for moving said lever as it unwinds near the end, thus turning the last-named ratchet-wheel by means of said pawl to an operative position when the pawl on the lower end of the reciprocating lever can engage the teeth of this ratchet-wheel, a cam-surface attached rigidly to a hollow shaft mounted on the axis of the ribbon-spool, a reversing lever mounted rigidly on the other end of the hollow shaft, having an arm to engage the above-mentioned cam-disk to throw the cam-surface on the hollow shaft to inoperative position so as to render the pawl and detent on the ribbon-ratchet effective for winding the ribbon, and means controlled by the unwinding of the ribbon for moving the ratchet-wheel having the inoperative portion to operative position.

17. The combination of a pair of ribbonspools, a ratchet-wheel for operating each spool, a step-by-step driving pawl for each ratchet-wheel, a detent-pawl for each ratchetwheel, a cam-surface for each set of pawls which prevents their operation when thrown into operative position, reversing levers and links connecting said cams to throw the one out of operative position when the other is in operation, a second pair of cams working in a plane approximately at right angles to the first set, a shaft for rotating each of said cams, al ratchet-wheel with an inoperative portion fastened to each of said shafts, two reciprocating arms pivoted on the frame of the machine for operating the above-mentioned pawls, a universal bar, type-keys for operating said universal bar, links connecting said bar and the reciprocating arms, springpressed pawls attached to said reciprocating arms and held against said ratchet-wheels which have an inoperative portion on their circumference, actuating levers, means for moving said levers by the unwinding of the ribbon from one of said spools, pawls loosely attached to each of said actuating levers and engaging said last-named ratchet-wheels for giving them a partial rotation to engage the pawls cn the reciprocating arms with the operative part of the ratchet-wheels, camplates rigidly attached to said last-named ratchet-wheels, and a projecting arm on each of said reversing levers for engaging said cam-plates.

18. In a ribbon-feed-reversing mechanism, the combination of a spool for winding a ribbon, means for feeding said ribbon automatically by movement of the keys, means for rendering said feeding means operative or inoperative, a reversing device consisting of a ratchet-wheel having a cutout-portion, a pawl co-operating with said ratchet-wheel to rotate it through means operated by movement of the keys, a cam rigidly connected with said ratchet-wheel, a reversing lever operated by said cam, means connected with said reversing lever to make the ribbon-feeding mechanism inoperative, mechanism operated by the movement of the ribbon to give said ratchet-wheel an initial movement so as to connect it with the operating pawl, and means to retain said mechanism in position for operation when the typewriter is being handled.

19. In a ribbon-feed-reversing mechanism, the combination of spools for winding a ribbon, means for feeding said ribbon automatically, means for rendering said feeding means inoperative, a reversing device consisting of ratchet-wheels having a cutout-portion in each, pawls co-operating with said ratchetwheels for operating the same, a cam rigidly connected with each of said ratchet-wheels, means for reversing the feeding mechanism for the ribbon operated by said cams, levers or arms engaged by an obstruction on the ribbon as it is being fed, springs for retaining said levers or arms in normal position against the action of said ribbon, weighted projections extending beyond the fulcrum of said levers or arms, and pawls connected with the levers and engaging said ratchetwheels to give them an initial movement and place the wheels in position for operation by the operating pawls.

20. In a ribbon-reversing mechanism for typewriting machines, the combination of a pawl operated at every key-stroke, a ratchet wheel having a notched portion in which said pawl normally works idly, an auXiliaryvpawl operable by the ribbon when a spool becomes unwound, to impartto said ratchet-wheel sufficient motion to enable the first pawl to engage and drive a tooth of the ratchet-wheel, and thereafter to effect, step by step, a cycle of movement of the ratchet-wheel; and means controlled by said ratchet-wheel for effecting a reversal of the direction of Winding of the ribbon.

2l. In a typevvriting machine having a ribbon-feed, the combination of means to reverse the direction of ribbon-feed, including a key-actuable ratchet-Wheel normally idle at the key-strokes, and means to enable the ribbon to rotate said ratchet-Wheel into co-operative relation with the keys, to enable the keys to actuate said reversing means and thereby change the direction of ribbon-feed.

22. In a typewriting machine having means for feeding a ribbon longitudinally in either one of two directions, the combination of means to automatically reverse either ribbon-feeding direction including a key-actuable ratchet-Wheel for each end of the ribbon, and normally idle at the key-strokes, and means to enable the ribbon to rotate either ratchet-Wheel into co-operative relation With the keys, to enable the keys to actuate a ratchet-Wheel and reverse the direction of a ribbon-feed.

23. In a typewriting machine having a ribbon-Winding mechanism, the combination of a drive-pawl moving at every type-stroke, a ratchetwheel operable by said drive-pawl, said ratchet-wheel having a gap in which said drive-pawl normally plays idly, and means brought into action automatically when one spool is full of ribbon, for starting said ratchet-Wheel so as to advance the gap past the paWl, whereby the latter drives the ratchet-Wheel, and means operated by said ratchet- Wheel for reversing the direction of Winding of the ribbon.

WILLIAM A. DOBSON.

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