US1096807A - Type-writing machine. - Google Patents

Description

J. O. MOLAUGHLIN. TYPE WRITING MACHINE. APPLICATION nun MAR. 23, 1910.

Patented May 12, 1914.

2 SHEET8-SHEET 1.

COLUMBIA PLANOGRAPH co wAsumamw. I) c.

J. O. MOLAUGHLIN- TYPE WRITING MACHINE.

APPLICATION FILED MAR. 23, 1910. Patented May 12,

2 SHEETS-SHEET 2.

COLUMBIA PLANDGRAFH C0,, WASHINGTON, D L

UNITED STATES PATENT JOHN C. MGLAUG'HLIN, 0F JERSEY CITY, NEW JERSEY, ASSIGNOR TO UNDERWOOD TYPEWRITER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

TYPE-WRITING MACHINE.

Specification of Letters Patent.

Patented May 12, 191 4.

Application filed March 23, 1910. Serial No. 551,060.

To all whom it may concern:

Be it known that I, JOHN C. MoLAUoH- LIN, a citizen of theUnited States, residing in Jersey City, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Type- Vriting Machines, of which the following is a specification.

This invention relates to means for performing the operation of condensed billing.

In Patent No. 924,525, granted to J. F. Allard, a platen-driving crank was rotatable through more than an entire revolution at one stroke, being mounted to rotate about the platen axis and having a dog or pawl to engage a notched wheel fixed to the platen axle. A stop was provided to limit the initial stroke of the crank, but the latter was enabled during its first revolution to pass freely by said stop, and yet to be arrested thereby, upon the second revolution in the same stroke of the crank. The point of the arrest was determined by the adjustment of the stop. In said patent, another stop was provided to limit the return stroke of the driver, but the crank was enabled during its first return revolution to pass freely by said returning stop, although the latter finally arrested the crank and platen.

The main object of this invention is to improve the devices whereby the crank and platen may be arrested, especially with a view to arresting the platen at all points within the capacity of the device, as well as to increase its capacity.

In the patent, a circular or segmentary rack was provided, and an adjustable stop could be set anywhere along this rack; but owing to the necessity of providing certain auxiliary devices, said rack was not made to extend around the entire circumference of the disk upon which it was formed. There was thus left a gap or dead portion equal to about one-third of the periphery of the disk, where the stop could not be set. iiccording to the present improvements, provision is made for setting the stop at different points throughout the entire circircun'iference of the disk, thus making the adjustment universal within the range of travel of the crank itself.

The dead portion of the disk is provided in the present invention with seats arranged at line space intervals, this series of seats over said capacity is increased, the machine now being capable of throwing the platen to any line-space position within two entire revolutions; although of course the improvement may be used for a shorter range of crank movement or of platen revolution.

In the accompanying drawings, Figure l is a rear perspective view from a point beyond the right-halal end of the platen, showing one form of my invention applied to a platen frame of the Underwood type of writing machine, the stop being arranged to arrest the backward rotation of the platen after it has made a trifle more than one revolution. Fig. 2 is a side view of the billing device removed from the platen frame, showing the normal positions of the parts, the billing device being disconnected from the platen. Fig. 3 is a similar view, showing the positions assumed by the parts when the platen is arrested on its backward rotation of a trifle over one revolution. Fig. 4 is a detail view of the opposite side of the billing device. Fig. 5 is a detail perspective view of the switch and its detent disassembled, and partly broken away to better disclose the construction. Fig. 6 is a cross sectional view through the device. Fig. '7 is a side view of the invention, showing the bill condenser released from the platen, the stop being arranged to arrest the platen before it has completed a full revolution. Fig. 8 is a similar view showing the parts in arrested position, the bill condenser connected with the platen. Fig. 9 is a side view shmving the parts in normal position, the stop being arranged to arrest the backward rotation of the platen after it has nearly completed two revolutions. Fig. 10 is a similar view showing the positions of the parts after nearly completing one revolution. Fig. 11 is a similar view showing the arrest of the parts after completing nearly two revolutions. Fig 12 is a detail perspective view of the interponent.

The usual platen 1 of an Underwood typewriting machine is rotatably mounted by means of an axle 2 in the ends 3 of a platen frame. To one end of the platen axle 2 (usually provided with a hand wheel, not shown) may be fixed a collar or boss 4", upon the outer end of which is secured a wheel 4, having teeth corresponding in num ber to the teeth of the usual line space wheel (not shown). This wheel, together with the axle and platen, is rotated by a driving pawl or dog 5, pivoted at 6, upon a crank'7, pivoted to swing about the axle 2, the crank7 thus forming a driver to rotate the platen. The tooth 8 of the pawl is normally disengaged from the wheel 4, as in Fig. 2, to pen mit rotation of the wheel and platen independently of the crank 7. The pawl 5 and wheel 4 form clutch members to connect the driver 7 to the platen for rotating the platen when the pawl is engaged with the wheel 4.

A pin 9 projecting from the pawl normally occupies a segmental recess 10 formed in the side of the annular rim 11 of a stationary disk or head 12, fixed by a tie rod 13 to the platen frame end 3. Said pin'9 normally overlies a latch 14 formed upon the side of a. small disk 15 mounted to turn or swivel in a circular bearing formed in the side of the disk 12 coincidently with the segmental recess 10.

The swiveled disk 15 has a stem 17 around which is'coiled a spring 18, one end of which is secured to a stud 19 on the swiveled disk, traversing a slot 20 in the head 12 to return the latch 14 to normal position. The slot and stud 19 limit the throw of the latch. A cap 21, threaded on the stem 17, retains the latch in place and incloses the spring 18.

The crank 7 is swung in the direction of the arrow, Fig. 2, so that the pin 9 rides down the forward inclined wall of the segmental recess 10 and presses down and passes by the latch 14. The latch is then returned to normal position by its spring 18 to form a continuation of the inner face of the rim 11.

The tooth 8 of the pawl '5 takes into one of the teeth of the wheel 4 as the pin escapes from the recess 10. The tooth is maintained in engagement with the wheel by the inner face of the rim 11, under which the pin takes as it leaves its recess, and the continued swing of the crank turns the wheel and platen to feed back the record sheet.

The arrest of the crank after more than a complete revolution of the platen is effected in part by an interponent or idle arm 22 loosely swinging about the axle 2 between the disk and the wheel, and lying in the path of movement of the pin 9 on the pawl. The latter forces the arm around and into contact with a stop pin 23 (see Fig. 6), the

,alinement with one of the seats 28.

the stationary disk or head 12. A spring 29 compressed between the nut 27 and a partition 30 in the tubular arm serves to draw the stop pin into any one of the seats 28, with its outer end lying in the path of the idle arm 22. The series of notches or.

seats 28 constitutes a curved rack extending partially around the platen axis. The pawlcarried pin 9 escapes the adjustable stop 23, which is only effective when engaged by the idle arm 22, and hence the platen can be turned throughout more than one rotation to accommodate long headings on bill heads.

Fast to the stop pin 23 isa stop pin 23 which can be brought into use by drawing out the stop 23. by the button 26 and rotating said button to bring said pin 23 in stop. pin 23 is long enough to project through the seats 28 so that it will arrest the pawl 8 directly, and so arrest the platen in less than one revolution, as described in said patent to Allard. Said pins 23 and 23 may also be swung to the position seen in Fig. 4, in which both are ineffective.

The back feed of the platen is arrested by the engagement of the pin 9 and interponent 22 with the stop 23 when the record sheet has been fed backwardly a distance equal to the width of the heading on the bill above the first line of writing. Such back feed is regulated to different widths of headings by the adjustment of the stop 23 in the seats 28. A fresh bill is then dropped into the machine and the crank 7 rotated in the opposite direction to advance both bill and record sheet simultaneously. To cause the first entry on the fresh bill to be transferred to the record sheet below the last line of writing thereon, the advancing feed of the platen is prolonged beyond or behind the forward end of the recess 10, the pin 9 riding under the latch 14 while the pawl 5 is still in engagement with the wheel 4.

As soon as the pin 9 reaches the gap between the rear end of the latch and the rear 2 same forward or backward, but the pawl remains longer in engagement with the wheel 4 on the forward feed thanon the back Said feed of the platen and thus spaces the entries on the record sheet.

The return stroke of the crank is arrested by the engagement of the pin 9 with a switch 32 normally lying in the path of the pawl-carried pin 9. On the back stroke of the crank, the pin engaged the under side of the switch and swung it about its pivot 3 1 to the position at Figs. 3 and 11, where it was not only ineffective to arrest the crank, but served to close the gap between the latch 14 and the rear end of the recess 10 in the annular guide 11, to prevent the entrance of the projection or pin 9, which rides past the recess and is maintained in engagement with the under face of the rim 11 until arrested by the contact of the pin 9, the interponent 22 and the stop 23, as already explained. During the return of the crank from the position in Fig. 3 to that in Fig. 2, the pawl-carried pin 9 engages the opposite end 33 of the switch to return the latter to normal position.

As so far described, the devices are shown in said Patent No. 924,525.

The pivot or stem 34 of the switch is journaled in the rim 11 of the head or disk 12, the end of the pivot having a crank 35 carrying a boss 35", which carries a springpressed detent 36 (see Fig. 5} to fit in depressions 37 on the back of tie disk to detain the switch 32 in either normal or gapclosing position until the switch is thrown by the pin 9 on the pawl 5. The pawl-carried pin 9 at the end of the paper-advancing stroke of the crank rides up the inclined switch 32 into its recess 10, to release the pawl from the toothed wheel 4 to permit the platen to be turned freely in either direction. Since the segmental recess 10, the switch 32 and the connection between the tie rod 13 and head 12 occupy a portion of the rim 11, the series of notches or seats 28 for the adjustable stop 23 usually extends along about two thirds of the circumference of said head.

To increase the capacity of adjustment of the device, so that the platen may be arrested at any line-space position Within the capacity of the crank 7, to accommodate bills having headings of any reasonable width without wasting the space thereon, or on the record sheet, there is provided an intermediate rack 38 lying between and connecting the ends of the circular rack 28. The rack 38 is formed by an offset lying concentric with the axis of the platen and covering the unnotched portion of the rim 11. Said rack is provided with a series of apertures or seats 39, into any one of which may be removably fitted a stop 1O preferably in the form of a screw. Said stop is engaged by the outer end of the interponent or idle arm 22 which, for this purpose, is provided with a laterally-projecting lip 41.

The seats 39 are spaced at equal intervals, and taken together with the equally-placed notches 28, agree with the number of spaces on the usual line-space wheel (not shown). By thus completin the series of stop-positions or seats on the disk, it is possible to feed the record sheet back and forth to any line position which the platen is capable of assuming in its rotation.

The platen may be rotated backwardly throughout any number of line-spaces less than a complete revolution, or any number of line-spaces more than one revolution and less than two complete revolutions, thus accommodating a great variety of widths of headings.

Figs. 1, 2 and 3 show an adjustment of parts whereby the platen is allowed to turn a trifle over one revolution. Fig. 2 shows the normal position of the parts, the platen being freely rotatable in either direction. Fig. 1 shows an intermediate position of the parts, the crank 7 having been swung a short distance to turn the platen backwardly to feed back the record sheet a corresponding distance. In this view, the pin 9 is shown as having picked up the idle interponent 22 to push it around the head until its lip 41 comes in contact with the stop 40 to arrest the crank and the backward feed of the record sheet, as shown in Fig. 3. It will be noticed in Fig. 2, that the stop 40 is located between the crank 7 and the interponent 22 to allow the crank to pass the stop before engaging said interponent.

To obtain a back feed of the record sheet through less than a complete revolution of the platen, for bills having narrow headings, it is only necessary to arrange the parts as shown in Figs. 7 and 8 for instance, wherein the interponent 22 is located between the stop 10 and the crank 7. In Fig. 7, the parts are shown in normal position, Fig. 8 showing the arrest of the crank be fore it has completed a full revolution.

Figs. 9, 10 and 11, show several positions assumed by the parts when arranged to effeet a backward rotation of the platen through nearly two rmolutions. It will be observed that the stop 40 is located precisely in the same position, as in 7 and 8, but that the interponent 22 is on the far side of the stop from the crank, as is better disclosed in Fig. 10. Thus, the crank is swung around the rack from the Fig. 9 position and past the stop 40, F ig. 10, picking up the interponent and carrying it during the second revolution of the crank, until the interponent is brought into contact with the stop at the completion of the stroke (as shown in Fig. 11).

The stop pin 23 may, if dcsired,be used as shown, for example, in Fig. 6, instead of the stop -10, when it is desired to arrest the crank at some point on the rack 28, the

interponent cooperating withthe stop 23 precisely the same as with the stop 40. That is, the stop 23 projects into the path of the interponent to arrest the latter when carried by the crank into engagement with the stop. In fact, from some points of View, the notches 28 and apertures 39 may be consid ered as forming a continuous circular rack with which a single stop at a time is used and cooperates to arrest the backward rotation of the driver and platen. In this point of view the racks 38 and 28 are merely sections of a continuous rack extending completely around the axis of the crank 7 Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. In a typewriting machine, the combination with a revoluble platen, of a revoluble driver therefor, stop means effective at any one of the regular line space graduations throughout a complete rotation of the platen, a device movable by said driver into engagement with the stop means to arrest the driver and platen, after the latter has turned through more than a complete revolution from normal position, and a device movable by said driver during the return stroke thereof, into position to arrest the driver upon its return to initial position.

2. In a typewriting machine,the combination with a platen, of a driver therefor revoluble about the platen axis and normally disconnected from the platen, a rack arranged circularly completely around the platen axis, stop mechanism including separate stops adjustable entirely around the rack, an interponent engaged by the driver and contacting with one of said stops to arrest the driver and platen at any point in their rotation, and a stop device to arrest the driver and disconnect it from the platen on its return stroke to initial position.

3. In a typewriting machine, the combination with a platen, of a driver. therefor revoluble about the platen axis and normally disconnected from the platen, a stationary rack member having notches extending partially therearound, a removable stop receivable in any one of the notches, a second rack member extending between and connecting the opposite ends of the series of notches in the first-named rack member, a removable stop adjustable relative to the second-named rack member, means effective to arrest the driver and platen at any point in their rotation by a selected one of said stops, and a stop device to arrest the driver and disconnect it from the platen on its return stroke to initial position.

4. In a typewriting machine, the combination with a platen, of a driver therefor revoluble about the platen axis and normally disconnected from the platen, a stationary rack member having notches extending partially therearound, a removable stop receivable in any one of the notches, a second rack member extending between and connecting the opposite ends of the series of notches in the first-named rack member, a removable stop adjustable relative to the second-named rack member, an interponent operable between the driver and a selected one of the stops to arrest the driver and platen at any point in their rotation, and a stop device to-arrest-the driver and disconnect it from the platen on its return stroke to initialgposition.

5. In a typewriting machine, the combination with a platen, of a driver therefor revoluble about the platen axis and normally disconnected from the platen, a rack having seats arranged completely around the rim thereof, the spaces between which seats correspond to line space intervals, stop means cooperable with any one of the seats, an interponent swinging about the platen axis to engage the stop means and lying in the path of the driver to be engaged thereby to arrest the driver and platen at any point in their rotation, and a return stop device to arrest the driver and disconnect it from the platen on its return stroke to initial position.

6. In a typewriting machine, the combination with a platen, of a driver therefor revoluble about the platen axis and normally disconnected from the platen, anotched rack extending part way around the axis of the platen, an apertured rack member completing the circle around the platen axis, a stop fitting in any one of the notches in the rack, a second stop to'seat in any of the apertures of the second named rack member, and an interponent swinging about the platen axis and engagin a selected one of the stops,-the interponent lying in the path ofthe driver to beengaged thereby, to arrest the driver and platen. at any pointin their rotation, and a stop device to arrest the driver and disconnect it from the plat-en on its return stroke to initial position.

7 In a typewriting machine, the combina tion with a platen and a wheel connected thereto, of a revoluble driver having a pawl to engage the wheel, a projection on the pawl, a rack comprising a disk having an annular guide for the projection, a portion of said guide having a circularly arranged series of seats formed thereon, a stop adapted to fit in any one of the seats, an interponent idly swinging about theplaten axis to connect the stop and projection to effect the arrest of the driver and platen, the remaining port-ion of the guide being recessed between the ends of the series of seat-s toaccommodate the projection when in normal position, and having a series of seats extending between and connecting the first-named series of seats, and a stop adapted to fit any one of said seats in the connecting series to cooperate with the interponent in the arrest of the driver and platen, and a stop device to arrest the driver and disconnect it from the platen on its return stroke to initial position.

8. In a typewriting machine, the combination with a platen, of a driver for retating the same, a stop for arresting said driver, a loose interponent rotatable about the axle of said platen and arranged to be arrested by said stop, a stop for arresting the backward rotation of the driver, and a rack for said first named stop arranged adjacent said second stop, whereby said first stop may cause said interponent to arrest said driver after a full rotation at selected points near the normal arrested position of the driver.

9. In a typewriting machine, the combination with a platen, of a driver for rotating it, a stop for arresting said driver, a loose iuterponent rotatable about the axle of said driver and arranged to be arrested by said stop, a stop for arresting the backward rotation of the driver and disabling it, and a rack for said first named stop arranged adjacent said second stop to arrest said driver near its normally disabled position but after a complete revolution of it.

10. In a typewriting machine, the combination with a platen, of a toothed wheel fast on the axle of said platen, a driver for said platen comprising a pawl to enter the teeth of said toothed wheel and rotate it in each direction, a fixed rack, an idle interponent journaled on said axle, a stop on an arm journaled on saidaxle adjustable on said rack to arrest said interponent to arrest the forward motion of said driver, means occupying a break in said rack for disengaging said pawl from said teeth at the limit of the backward throw of the driver, and a rack to hold a stop adjacent to said disengaging means to enable said driver to be arrested at such adjacent points.

11. In a typewriting machine, the combination with a rotatable platen, a driver for rotating same, an interponent for arresting said driver, a stop for arresting said interponent, a rack for said stop adjacent the plane of rotation of said driver, means for normally holding the driver disconnected from the platen at one point in its path of revolution, and a supplementary rack adja cent said point, said supplementary rack and said first-named rack forming a complete circumference.

12. In a typewriting machine, the combination with a rotatable platen and a driver for rotating the same, of a rack adjacent the plane of rotation ofsaid driver, an idle interponent, stopping means settable in said rack to arrest said driver either by said interponent or directly, means for normally ho1ding said driver disconnected from the platen, a supplementary rack, the two racks forming a substantially complete circumference, and stopping means settable in said supplementary rack.

13. In a typcwriting machine, the combination with a rotatable platen and a driver therefor, of means fixed on the axle of said platen, means carried by said driver adapted to engage said means fixed on the platen axle, an arcuate rack adjacent the plane of movement of said driver, stopping means settable on said rack, means for normally holding said driver disconnected from said platen between the ends of said arcuate .ack, a supplementary rack covering the arc occupied by said holding means, and stopping means settable in said supplementary rack.

14. In a typewriting machine, the combination with a rotatable platen and a driver therefor, of an idle interponent, a rack adjacent the plane of rotation of said interponcnt and said driver, stopping means settable along said rack, means for normally holding said driver disconnected from sa d platen at an interrupted portion of said rack, and a supplementary rack covering the interrupted portionof said rack.

15. In a typewriting machine, the combination with a rotatable platen having an axle, of a driver for said platen rotatable on said axle, an idle interponent swinging idly on said axle, a fixed rack adjacent said plane of rotation of said driver, means for positively disconnecting the driver from the platen at one point in its rotation, said means occupying part of the circumference of said rack, stopping means selectively settable in said rack to arrest said driver either directly or by said interponent, a supplementary rack occupying a portion of the circumference of said rack occupied by said disconnecting means, and stopping means settable in said supplementary rack.

16. In a typewriting machine, the combination with a rotatable platen having an axle, and a driver pivoted on said axle, of an interponent loose on said axle, a fixed member encircling said axle, a clutch memher on said driver adapted to be connected with a part rotating with said platen, an arcuate rack on said fixed member, means for positively disconnecting said clutching member from said part at a point in the circumference of said fixed member not occupied by said rack, a supplemental rack occupying a portion of said circlunfcrence, and stopping means for each rack settable for arresting said interponent.

17. The combination with a platen having a toothed wheel fast thereon, of a fixed rack adjacent thereto, a driver for said platen, a pawl moved by said driver to rotate said platen, a stop settable on said rack to arrest said driver, an idle interponent movingwith said driver, a second" stop fast to said first stop adjustable along said rack and settableon said rack when saidv first stop is in ineffective position to, arrest said driver by said interponent, said stops both settable to ineffective positions, means. for positivelydisconnecting said pawl from said. toothed wheel at one point along said fixed rack, a supplementary rack at said point,- and astop. settable on said supple 'mentary rack when said first two stops are in. their ineffective positions.

18. The combination with a platen and a driver therefor, of a fixed member adjacent said driver a rack. formingpart of the periphery of. said fixed-member, a pawl carried by said driver for seizing a wheel carried by said platen, said; pawl; traveling adjacent said rack, stops. settable along said rack for arresting saidv driver, means on said fixed member forpositively disconnecting said pawl from said platen, a rack adjacent said disconnecting means, an interponent for arresting said. driver by one of said stops, and a part on said pawl cooperating with. an-. other stop to arrest said driver independently of said. interponent 19. The cornbinationwith a platen and an axle therefor, of a rack encircling, said axle, a driver, means connecting said driver and platen for rotating the platen baokwardly through a. large, number of line-spaces and then returningit forward through. a. larger number of line-spaces, and means-settable on said rack at linesspace intervals throughout a complete circumference for automatically arresting. said driver at any desired linespace in the revolution of said platen.

20. The combination with a platen and an axle therefor, of. a rack encircling said axle, a driver, means connecting said driver and platen. for rotating. said platen backwardly through a large number of linespaces, notches on, said rack for, accommodating stops atv any desired line -.space in a complete revolution of. said, platen, stopping means settable in said notches for so arrestingsaid platen, and means for causing the forward rotation. of said platen byv said driver to turn said platen through a larger number of line-spaces thanit's backward rotation by said driver.

21. The combination with a platen and an axle therefor, of a rack encircling said platen, a driver. loose on. the axle of said platen, disengaging means for clutching said driver to. said platen. to turn the platen backward a. large number of line-spaces,stopping means settable. on said. rack to arrest said driver at any desired line-space in a complete. rotation of said platen, and means for causing said driver on its forward rotation totur-n said: platen a larger number of said. line=spaces-.

22. The. combination of a, platenv and an. axle therefor, a driver for turning said platen,a fixed member adjacent said driver, means for connecting said driver to the platen to turn said platen backwardly through a large number of line-spaces,means settable on said fixed member at a series of points extending completely around the axle for determininghow many line-spaces said platen shall so be turned, and means for causing said driver to turn said platen through a larger number of line spaces on its forward rotation. I

23. The combination wit-h a platen and an axle therefor, of a driver-pivoted on the axle of said platen, a device for causing said driver to positively engage said platen during a large. number of line-spaces. on its backward rotation and for positively causing it to engage the platen during a larger number of line-spaces on its forward rotation, a rack adjacent said driver, and means settable on said rack for arresting said driver at any line-space in a complete revos lution.

24, The combination with a platen and an axle therefor, of a driver for positively turning said platen backwardly and forwardly, a device for causingsaid. driver to turn said platen in one direction a greater distance than the other, a fixed member encircling said axle, and means settable on said fixed member at line-space intervals throughout a complete circumference. for causing-said platen to be arrested at any line-space in-,itsrevolution.

25. The combination with a, platen, of; an axle therefor, a wheel. forming a. clutch member fast on said axle, a driver-for said platen, a pawlforming a clutch member on said driver, means, for locking said clutch members together to cause said driver to one direction to be arrested at. anylineespacesin.its complete revolution, means. for positively connecting said clutch members. during.- the backward rotation OfSZLld. platen. through a predetermined number ofnlinesspaces, and means for positively connecting said driver to said; platen by. said clutch members through. a larger number of line;spaces. dur-.

ing itsv forward rotation.

27. The combination with a platen and an axle therefor, of a driver pivoted on said axle, a clutch composed of a pawl and wheel between said driver and said axle, a fixed rack adjacent said clutch, means settable on said fixed rack to arrest said platen at any desired line-space in its complete revolution, means normally holding said clutch mem bers inoperative, and means for positively making said clutch members inoperative after they have moved said platen forward a greater number of line-spaces than they moved said platen backward.

28. The combination with a platen and an axle therefor, of a clutch member on said axle, a driver pivoted on said axle, a clutch member engaged by said driver, means normally holding said clutch members ineil'ective, means positively engaging said clutch members on the backward revolution of the platen, a fixed rack encircling said axle, means setta-ble on said fixed rack for arresting said platen at any line-space throughout a complete revolution, and a separate device for positively releasing said clutch members after they have turned said platen forwardly a greater number of linespaces than they moved said platen backwardly.

29. In a typewriting machine, in combination, a platen, a driver for rotating the same, a circular rack extending completely around the axis of said driver adapted to hold stopping means to arrest said platen at any line space, an interponent freely rotatable on said axis, stopping means adapted to be fixed on said rack and projecting into the path of said interponent, said driver being adapted to advance said interponent until it strikes said stopping means.

30. The combination with aplaten, a crank rotatable about the platen axis, and an interponent member rotatable about the platen axis independently of the crank, of a rack, stop means, and provision for setting the stop means at different points throughout the entire circumference of the rack, and adjusting said stop means universally within the range of travel of the crank itself, substantially as set forth.

JOHN C. McLAUGHLIN.

\V i tnesses K. Fnanxron'r, C. RIPLEY,

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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