US2050177A - Typewriting machine - Google Patents

Description

Aug. 4, 1936'.

:5 sheet-sheet 1 Filed Sept. 5, 1954 ATToRMaYl Filed Sept. 5,4 1954 s sheets-snaar 2 ATTORNEYS y ug- 4, 1936- G, F. HANDLl-:Y

TYPEWRITING MACHINE Filed Sept. 5, 1954 s sheets-sheet 5 lNvENToR G' BY ATTORNEYS Patented Aug. 4, 1936 UNi'i STATES ATENT GFFECE TYPEVVRITIN G MACHINE George F. Handley,

Royal Typewriter Glendale, N. Y., assignor to Company, llnc., New York,

1l Claims.

This invention relates to improvements in typewriting machines generally and in machines of analogous arts, although more particularly to improvements in automatic ribbon reversing mechanisms such as is disclosed in my Patent 1,570,218, January 19, 1926.

The invention relates broadly to devices for reversing the feed of the ribbon when one spool is substantially empty, and more specifically to a reversing means operated by a projection carried by the ribbon. It is illustrated in connection with the portable Royal typewriter, but it is to be noted that it can be employed with other typewriting machines or with other types of machines wherein a ribbon is fed step by step through the operation of keys orequivalent parts.

Among the several objects of my invention are to provide a ribbon reversing mechanism in which the ribbon will begin a positive reverse winding movement immediately upon the reversing mechanism becoming effective and without any slack or loop being formed in the ribbon between the ribbon guide finger and the spool; to provide means for preventing the jamming of the reversing mechanism should any one either intentionally or unintentionally move the guide fingers inwardly, and to provide such a reversing mechanism which is composed of comparatively few parts and is therefore not only cheap to manufacture but is durable in operation.

In the drawings:-

Figure 1 is a sectional front elevation of a ribbon reverse mechanism with certain parts omitted, the mechanism being shown in operating position.

Figure 2 is a horizontal sectional view taken on the irregular line 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 is a fragmentary top plan view of the construction shown in Figure 1 with certain parts omitted.

Figure 4 is a view similar to Figure 1 but showing some of the associated parts in advanced Working positions.

Figure 5 is a detail elevation, partly in section, sho-wing the ribbon reversing elements in their reversed positions.

Figure 6 is a detail sectional view taken on the line 6-6 of Figure. 3 looking in the direction of the arrows, the parts being in their normal positions.

Figure 7 is a similar view to Figure 6 but showing the ribbon guide at the extreme inner end of its movement and the reversing pawl still in its effective position.

Figure 8 is a view similar to Figure 6 but showing the. reversing pawl in a position just after it has started to return to its initial po- 5 sition.

Figure 9 is an enlarged perspective View showing the spiral wheel and the associated rotary camming element, together with the lower end of the reversing pawl in eifective engagement l0 with said wheel.

Figure 10 is a perspective View of the thread guide and arm.

Figure 1l is a perspective view of the reversing pawl together with the interponent which is pivoted thereon.

Figure 12 is an enlarged detail front elevation of the pawl and worm in operative engagement.

Figure 13 is `a detail elevation showing a modied form of interponent.

Referring to the accompanying drawings, 5, 5 indicate the side walls of the main frame of a type writing machine. Attached to the inner faces of these walls are vertical brackets A, A, each bracket including a rearwardly extending wall 6 having upper and lower inwardly extending horizontal arms 'l and 8. Journaled in each pair of arms 'I and 8 is a vertically disposed spool shaft 9 having mounted on the upper end thereof a ribbon spool il). A ribbon II is alternately wound on the spool, means being provided to automatically reverse the rotation of these spools in order to effect this alternate winding of the ribbons. Journaled in the brackets A, A below the spool shafts 9 is a driving shaft I2 which is 35 not only free to rotate but is also free to be reciprocated longitudinally. Fixed to the lower end ci" each spool shaft 9 is a beveled gear I3. Fixed to the driving shaft I2 .are beveled gears I4, I4 which are .adapted to alternately engage the 40 gears I3, I3 and thereby effect alternate rotations of the ribbon spools I. The driving shaft I2 is intermittently rotated through. the medium of a ratchet wheel I5 xed thereon and a cooperating pawl I6 which is actuated from the uni- 45 versal bar Il whereby the shaft will be rotated step by step at each depression of a type bar key lever. Adjacent one of the beveled gears I4, the shaft I2 is provided with a xed collar I8 having two peripheral grooves I9 and 29 therein. A 50 spring pressed detent 2l is pivoted to the lower arm 8 of the associated bracket A and cooperates with the grooves I9 and 2Il to hold the shaft I2 in either of its longitudinal or endwise adjustments, whereby one of the beveled gears I4 will 55 be held in engagement with its associated beveled gear I3 while at the same time the other gear coupling I3, I4 will be held in disengaged relation. In order to reverse the rotations of the spools I0, the shaft I2 is automatically reciprocated endwise, the spring detent 2l being cammed from one groove I9 or 20 into the other of said grooves. This driving shaft I2 is automatically reciprocated endwise by the movement of the ribbon I I as it is being unwound from each spool by the following mechanism:-

Fixed to the ribbon II adjacent each end thereof is a button or projection 22 which as the ribbon is nearly fed oiI the associated spool, engages a ribbon guide 23 and moves the latter in a direction away from the spool. The guide 223 is attached to the inner end of a horizontal arm 24 which is mounted on the bracket A for a straight line movement in a horizontal plane, the inner end of the arm 24 being provided with a longitudinal slot 25 through which a stud or screw 26 passes into a part of the bracket A, the outer end of the arm 24 being slidably supported in an opening 2'I formed in the brack-et A. It will be noted that the ends of the slot 25 serve as stops to limit the sliding movement of the ribbon guide. The inner end of the slot 25 is normally engaged with the associated stud 23 and consequently as the ribbon unwinds the button or projection 22 will engage the guide 23 and thereby move said guide together with its arm 24 inwardly in a straight line and in a horizontal plane. Rigidly connected to the guide arm 22 .and preferably formed integral therewith and extending downwardly therefrom is a trailing cam 28 which consists of a straight inclined edge disposed at an angle of less than 30 to the horizontal. Slidably supported for vertical movements in guide openings in the bracket arms I and 8 is a reversing pawl 29, said pawl including an upwardly extending guide arm 30. A coil spring 3E has one end connected to the pawl 29 and the other end to the upper bracket arm "I and functions to yieldably retain the pawl in its upper or inactive position. Associated with each reversing pawl 22 is a helical toothed wheel or worm 32 which is fixed to the driving shaft I2 below said pawl. The pawl 29 in horizontal cross section is inclined relative to the axis of the driving shaft I2 in order to register with the inclined teeth 32e of the wheel 32, the opening in the lower horizontal bracket arm S being correspondingly inclined to receive the pawl 29 and maintain the same in its angular relation while being reciprocated vertically.

It will, therefore, be seen that when the pawl 29 is moved downwardly into engagement with the teeth 322L of the wheel 32 the intermittent rotation of the latter will through its cooperation with the pawl 2S cam the driving shaft I2 outwardly to effect an engagement between the associated bevel gears i3 and I4 and thereby reverse the direction of rotation of the associated spool I0. The distance of travel of the pawl 29 is considerably less than the travel of the ribbon guide 23, and in order to positively move the pawl 29 downwardly into engagement with the teeth of the associated wheel 32, I have provided a yieldable interponent 33 which is pivoted intermediate its ends as at 34 to the upwardly extending guide arm 30 of said pawl 29. The interponent 33 is in the nature of a lever and is centrally formed on its upper edge with a concentric portion 3 which merges with an eccentric portion 36. This interponent is located directly below the upper bracket arm I and in the normal position of the parts the concentric edge 35 of said interponent is held in yieldable and slidable contact with the lower face of upper bracket arm l by means of the coil spring 3l. An arm 38 which depends from the forward end of the interponent terminates in a laterally extending stop finger 39 which normally engages the forward edge of the guide arm 30 of the reversing pawl 2S). The rear end of the interponent forms a cam finger 40 which projects under and is at all times held in sliding contact with the cam 28 on the guide arm 24.

In operation, as the ribbon unwinds from a spool I2 the button or projection 22 which is fixed to and travels with the ribbon engages the ribbon guide 23 and moves the latter inwardly in a straight horizontal line During this inward movement of the ribbon guide 23, the cam 28 which is carried by the guide arm 24 is caused to depress the cam finger 40 of the interponent 33 and thereby swing the latter against the tension of its spring 3 I. During this swinging movement of the interponent the eccentric edge 38 thereof slidably engages the upper bracket arm 'I which, being fixed, functions as an abutment whereby the pawl 29 will be depressed against the tension of its spring 3l into engagement between a pair of teeth of the associated spiral wheel 32 and thereby cam the driving shaft I2 endwise and effect a, coupling of the associated bevel gears i3, Iii. Inasmuch as the amount of intermittent movement imparted to the ribbon may vary to a slight extent due to the tightness or looseness with which the ribbon is wound on the spool, the parts have been timed and constructed so that the pawl 29 will become active before the ribbon guide 23 reaches the limits of its inward movement under the influence of the ribbon button or projection 22.

As soon as the reversing driving connection between bevel gears I3, I4 has been rendered eiective, the ribbon guide 23 will be returned to its initial position. This return movement of the ribbon guide is effected slowly and without forming a bow or slack in the ribbon between the button 22 and the spool I0. This condition is brought about by reason of the angle of the cam 28 being relatively small, it being preferably less than 30 as stated. Consequently, the cam will be returned by gravity plus a slight assistance by the spring SI, at a much slower rate of speed than if a cam of a larger angle were employed. This is very important because it avoids the necessity of taking up such slack prior to the initial starting of the reverse movement of the ribbon. Thus the reverse movement of the ribbon starts practically simultaneously with the coupling of the two reverse bevel gears E3, I4 and consequently the ribbon will not receive a plurality of type impacts at a single point. As soon as the bevel gears I3, i4 are engaged, the spiral wheel 32 will become disconnected from the pawl 29 and immediately thereafter the ribbon guide 23 will be oammed to its initial position, due to the spring Si exerting an upward pull on the pawl 29 whereby the cam finger 421 will ride along the cam 28 and slowly move the guide 23 inwardly to its initial position, By reason of the cam 2B being disposed at an angle less than 30 to the horizontal, this inward movement of the guide will be sufficiently slow to avoid the possibility of forming a loop or slack in the ribbon between the button 22 and the spool.

I have also provided means which not only initially starts the reversing pawl 29 in its return or upward movement but also functions to avoid the pawl interfering with the endwise movement of the driving shaft I2 should any one manually move both ribbon guides 23 inwardly simultaneously. To this end, I have attached rigidly to the inner face of each spiral Wheel 32 a camming element 4l having a smooth concentric periphery 42 and an inner beveled face 43, the periphery 42 being spaced from the spiral wheel or worm 32 and the bevel or cam inner face 63 being located therebetween. The diameters of the worm 32 and the camming element ll are substantially equal. As the driving shaft l2 begins to move endwise under the conjoint action of the reversing pawl 29 and the spiral gear 32, the latter will gra-dually be moved from engagement with the pawl and the latter will be gradually moved into engagement with the bevel or circular cam 43 and thereby impart an initial lifting movement to the reverse pawl 29. Should any one move the ribbon guides 23 inwardly simultaneously, one of the pawls would be caused to engage the associated spiral whe-el 32 while the other pawl would be moved downwardly below the roots of the teeth 32a of the associated wheel 32 and thereby prevent the shaft l2 from being moved endwise, but by providing the cam element ll as above described, I have provided means for preventing the reverse pawl 2 9 from being moved downwardly to block the return movement of the driving shaft l2 as the pawl will engage the concentric surface 42 of the element ll and thereby retain the pawl above the roots of said teeth.

Should the pawl 29 be moved downwardly into very tight contact with a tooth root on the wheel 32, which might occur if the ribbon guide 23 is moved too far by hand or by the ribbon button 22, the pawl and the wheel will jam and the shaft l2 will not be shifted. To avoid this condition, and thereby insure the proper reversing of the ribbon, I have provided a modified form of interponent as shown in Figure 13. This interponent is provi-ded with an eccentric edge #i5 which normally engages the abutment l, and

. with a concentric edge which merges with the eccentric edge 45, the concentric edge 45 engaging the abutment 'l when the pawl 29 is located just above the root of the teeth 32a of the wheel 32. This further rocking movement of the interponent will not transmit further downward movement to the pawl. The interponent is provided with a cam finger ooe for engagement with the cam 28, and with an arm 38e which terminates in a stop 39a. A coil spring 41 which is i connected to the arm 38e an-d to the guide arm 36 of the pawl 29 functions to return the interponent to its initial position.

I claim:

1. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a longitudinally movable driving shaft normally disconnected from the spool shaft, and means including a cam shiftable horizontally by the ribbon for moving the driving shaft longitudinally to thereby eifect a driving connection between the spool shaft and the driving shaft.

2. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from th-e spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the worm being fixed to the driving the pawl with the worm including a guide movable in one direction by the ribbon during the' unwinding of the latter, and a cam shiftable horizontally with the guide locate-d between the ribbon guide and the pawl for moving the latter into engagement with the worm.

3. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from the spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal n1ovement, the worm being fixed to the driving shaft, said pawl being movablev in Va straight vertical path, a spring for normally retaining the pawl out of engagement with the worm, and ribbon actuated means for engaging the pawl with the worm including a guide slidably mounted for a straight line horizontal movement by the ribbon during the unwinding of the latter, and a cam shiftable horizontally with the guide located between the ribbon guide and the pawl for moving the latter against the tension of its spring' into engagement with the worm.

4. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from the spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the worm being xed to the driving shaft, and ribbon actuated means for engaging the pawl with the worm including a guide movable in one direction by the ribbon during the unwinding of the latter and provided with a cam, and a yieldable interponent pivoted on the pawl and engageable with the cam for moving the pawl into engagement with the worm.

5. A ribbon reversing mechanism for typewriting machines including a main frame, a bracket mounted on the frame and including an abutment, a vertical ribbon spool shaft journaled lin the bracket, a horizontal driving shaft normally disconnected from the spool shaft and supported on the frame for longitudinal ov'ement for operative connection with the spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the pawl being mounted in the bracket for vertical movements and the worm being xed to the` driving shaft, a for normally retaining the pawl out of engagement with the worm, and ribbon actuated means for engaging the pawl with the worin including a guide movable in one direction the ribbon during the uni/vinding of the latter, inclined trailing cam movable with the guide, and a yieldable interponent pivoted on the pawl and having sliding contact with the abutment and with the cam.

6. A ribbon reversing mechanism for typewriting machines including a main frame, a bracket mounted on the frame and including an abutment, a vertical ribbon spool shaft journaled in the bracket, a horizontal driving shaft normally disconnected from the spool shaft and supported on the frame for longitudinal movement for operative connection with the spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the pawl being mounted in the bracket for vertical movements and the worm being xed to the driving shaft, and ribbon actuated means for ing shaft, and ribbon actuated means for engagengaging the pawl with the worm including a guide movable in one direction by the ribbon during the unwinding of the latter, an inclined trailing cam movable with the guide, a yieldable interponent pivoted on the pawl and having sliding contact with the abutment and with the cam, and a coil spring connecting the pawl and the bracket for yieldingly retaining the pawl against movement and for retaining the interponent in sliding contact with the abutment.

'7. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from the spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the worm being fixed to the driving shaft, said pawl being movable in a straight vertical path, a spring for normally retaining the pawl out of engagement with the Worm, ribbon actuated means for moving the pawl into engagement with the worm, means for returning the pawl to its normal position, and means for retaining the pawl against being moved downwardly alongside of the worm to a point below the roots of the teeth of the worm.

8. A ribbon reversing mechanism for typewritlng machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from the spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the worm being fixed to the driving shaft, said pawl being movable in a straight vertical path, a spring for normally retaining the pawl out of engagement with the worm, ribbon actuated means for moving the pawl into engagement with the worm, means for returning the pawl to its normal position, and means for retaining the pawl against being moved downwardly alongside of the worm to a point below the roots of the teeth of the worm, said preventing means comprising an element xed to the driving shaft adjacent the worm and having a smooth concentric periphery located in the path of movement of the pawl, the diameter of the element being substantially equal to the diameter of the worm.

9. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from the spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the worm being fixed to the driving shaft, and ribbon actuated means for engaging the pawl with the worm including a guide movable in one direction by the ribbon during the unwinding of the latter, cam means located between the ribbon guide and the pawl for moving the latter into engagement with the worm, a spring for returning the pawl to its normal position, and cam means mounted on the shaft for positively starting the pawl in its return movement.

10. A ribbon reversing mechanism for typewriting machines or the like comprising a ribbon spool shaft, a driving shaft normally disconnected from the spool shaft and mounted for longitudinal movement for operative connection with said spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the worm being fixed to the driving shaft, said pawl being movable in a straight vertical path, a spring for normally retaining the pawl out of engagement with the worm, ribbon actuated means for moving the pawl into engagement with the worm, turning the pawl to its normal position, and means for retaining the pawl against being moved downwardly alongside of the worm to a point below the roots of the teeth of the worm, said preventing means comprising an element fixed to the driving shaft adjacent the worm and having a smooth concentric periphery located in the path of movement of the pawl, the diameter of the element being substantially equal to the diameter of the worm, said element being formed with a downwardly, inclined circular cam located between said smootli peripheral surface and the gear for positively starting the pawl in its return movement.

ll. A ribbon reversing mechanism for typewriting machines including a main frame, a bracket mounted on the frame and including an abutment, a vertical ribbon spool shaft journaled in the bracket, a horizontal driving shaft normally disconnected from the spool shaft and supported on the frame for longitudinal movement for operative connection with the spool shaft, a normally disengaged pawl and worm for giving the driving shaft said longitudinal movement, the pawl being mounted in the bracket for vertical movements and the worm being fixed to the driving shaft, a spring for normally retaining the pawl out of engagement with the worm, and ribbon actuated means for engaging the pawl with the worm including a guide movable in one direction by the ribbon during the unwinding of the latter, an inclined trailing cam movable with the guide, a yieldable interponent pivoted on the pawl and having sliding contact with the abutment and with the cam, said interponent having an eccentric edge normally contacting the abutment and a merging concentric edge engageable with the abutment after the pawl engages the teeth of the worm and preventing the pawl from contacting the root of the worm GEORGE F. HANDLEY.

means for reteeth. 60

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