US2370478A

US2370478A - Typewriting machine

Info

Publication number: US2370478A
Application number: US426828A
Authority: US
Inventors: Miles H Mann
Original assignee: Underwood Elliott Fisher Co
Current assignee: Underwood Elliott Fisher Co
Priority date: 1942-01-15
Filing date: 1942-01-15
Publication date: 1945-02-27
Anticipated expiration: 1962-02-27

Description

Feb. 27, 1945.

M. H. MANN TYPEWRITING MACHINE Filed Jan. 15, 1942 5 Sheets-Sheet 1 ATTORNEYY Feb. 27, 1945. M. H. MANN IYPEWRITING MACfiINE Filed Jan. 15, 1942 5 Sheeisheet 2 ATTORNEY Feb. 27, 1945. M, H. ANN 2,370,478

TYPEWRITING MACHINE Filed Jan. 15, 1942 5 Sheets-Sheet 3 INVENTOR /7/5 H. MA/V/V BY &

K ATTORNEY I Feb. 27, 1945. M. H. MANN TYPEWRITING MACHINE Filed Jan. 15, 1942 5 Sheets-Sheet 4 INYENTOR /'7/L[5 l7. I

ATTORNE Feb. 27, 1945.

M. H. MANN TYiEWRITING MACHINE Filed Jan. 15', 1942 5 Sheets-Sheet 5 INVENTOR /V/L5 H. IVA/V/V B ATTORN EY Patented Feb. 27, 1945 TYPEWRITING MACHINE 'Miles H. Mann, West Hartford, Conn., assignor to Underwood Elliott Fisher Company, New York, N. Y., a corporation of Delaware Application January 15, 1942, Serial No. 426,828

17 Claims.

This invention relates to typewriting machines and more particularly to machines usually referred to as fanfold or continuous billing machines, wherein carbon sheets are supported in interleaved relation between continuous webs, or the plies of a fanfolded web, and are shiftable or retractable therealong for registration with succeeding web portions or forms.

Patent No. 2,275,782, issued to Miles H. Mann, dated March 10, 1942, features such a machine equipped with a power mechanism for retracting the carbon sheets, and it is a major object of the present invention to improve upon the machine of the said application.

Although, as in the said prior application, the various features of the invention are shown applied to a machine embodying the structure shown in the patent to Wernery and Smith No.

1,132,055, dated March 16, 1915, they are to be regarded as applicable also to other writing machines, particularly such wherein carbon sheets are successively registered with succeeding portions of a continuous work web It is another object of the invention to provide an improved motor-driven carbon-retracting device.

A further object of the invention is to provide durable and inexpensive transmission means whereby a stationarily located motor may actuate a carriage-supported carbon-retracting device.

It is also an object of the invention to produce improved controlling devices whereby a motor-driven carbon retracting device is adapted to be rendered effective and ineffective.

A further object of the invention is to furnish eflicient automatically-acting means to prevent rebounding of the carbon-carrier after its retraction to a certain position.

Another of the objects of the invention is to provide a simple and effici'ent carbon-retracting device which is normally biased to advance the carbons.

Still other important objects and features of the invention will be apparent upon consideration of the detailed description which follows, as that descript on is read in the light of the accompanying drawings.

Referring now to the drawings:

Figure 1 is a general perspective view of a Figure 3 is a right-hand sectional side elevation showing a carbon carrier in an advanced position upon a typewriter carriage, a portion of a leading form having been typed upon, v

Figure 4 is a View similar to Figure 3 but shows the carbon carrier at the moment of full powerretraction,

Figure 5 shows diagrammatically a motor and circuit controls therefor,

Figure 6 is a fractional plan view of a portion of the carbon retracting mechanism, the retracting mechanism being idly conditioned,

Figure, '7 is a sectional front view taken ap proximately along line 'l! of Figure 6, showing a portion of the carbon retracting device,

Figure 8 shows a transverse section through a belt drum constituting part of the carbon re tracting device, a

Figure 9 is a fractional plan view of a mechanism whereby carbon retracting motion is transmitted from a stationarily located motor to a carbon retracting mechanism on the carriage,

Figure 10 is a fragmentary plan view and shows the carbon retracting device ineffectively conditioned as a result of the retraction of the carbon carrier, and further shows a device effectively conditioned to check forward rebounding of the carbon carrier, I

Figure 11 is a fractional plan view which illustrates certain controlling devices for a clutch of the carbon retracting device in normal position,

Figure 12 shows a portion of the mechanism shown in Figure 10, the clutch having been closed by the operation of the controlling devices, and

Figure 13 illustrates a dash-pot control which forms part of the rebound checking device for the carbon carrier.

Referring now particularly to Figure 1, a carriage H3 is mounted'to travel upon front and rear rails I l, l2 of a stationary typewriter frame, generally designated by the numeral I3. A usual spring motor, not shown, moves the carriage in letter-feed steps in response to each typing impression made by type-bars IS. The illustrated carriage l0 comprises a main frame l6, a caseshiftable frame l'l within the carriage frame it, and a pivotally displaceable sub-frame l8 carrying a writing support 'in the form of a platen 2!. The frame I! is case-shiftably mounted within the main carriage frame IS, in a manner not shown, but as is usual in Underwood typewriting machines, and comprises end plates 22 connected by several cross bars, one of which is indicated at 23 in Figures 2 and 3. The displaceable sub-frame l8 isshown to include two opposite end pieces 24 rigidly connected by a bar 25, see Figures 2 and 3. The displaceable sub-frame I8 is normally located within the case shift frame I! sothat the platen 2| bears upon front and rear feed rolls 26 and 21, respectively, see Figures 2 and 3. The sub-frame I8 is pivotally supported by means of studs 28 extending inwardly from the case-shift frame end-plates 22 into the end pieces 24. At the rear ofthe platen, the end pieces 24 of the sub-frame [8 seat normally upon collars 29 provided upon a rod 32.. The rod 32 is pivoted in the opposite end plates 22 of the frame I! and. i

has near eachof its opposite ends a latch arm 3| secured to it. Each arm 31 has: a hook forma-' tion 33 that normally overlies a pin 34 on an end piece 24 of the sub-frame to hold the latter down. The hook or latch arms 3| are rearwardly swing.- able to clear the pins 34 and to render thereby the said sub-frame i8 displaceable to the position seen in Figures and, 4. A spring. 35 by engaging va downwardly extending branch 36. on one of the arms 3| tends'toswingthe arms3l forwardly into latching position, .the. downwardly extending branch 36 limiting the forward motion of the latch arms by engagement with the bar. 23.. The platen 2! is rotatablewithin the displaceable subframe I8 by means of a Spindle 31., the spindleextending through the end. plates 24 of. the subframe l8 and having at each end a gear 38 secured to it. Adjacent to each gear 38 is another gear 4;! secured to a stub-shaft. 42 which. is revolvably mounted upon the adjacent case-shiftframe end-pla-te 22. As seen inFigure 1, there. is

provided upon each end of the carriage, another ,1

gear 43 meshing with one of each of the gears 38 and 4|. Each stub shaft 42 is revoluble. by a knob 44; and since each gear 43 is in mesh with a gear 38. and a gear 4|, theplaten 21- is revoluble by turning either one of the knobs 44.

Attached to the rear of. the carriage Ill isv a rectangular extension or shelf 45, formed of lightgage sheet metal andv having weight-reducing openings 46. This extension is formed with downwardly-turned flanges 41 along the periphery and also along said openings 46 to; stiffen. it. At the forward end, the extension is slidably carried for small laterally limited movements upon. a rod 48 extending intermediate two spaced brackets 51: reaching rearwardly from the typewriter carriage I6. The brackets 5| are secured to a rear bar 49 of the main carriage frame l6, and the carriage extension 45, therefore, does not case-shift with the case-shift. frame I1. Rearwardly of. the carriage Hi, the extension '45 has secured tov it a downwardly reaching bracket 52 carrying a plurality of laterally spaced rollers 53 adapted to run in a channel bar 54 secured to a framework. 55 extending from the. rear. of thetypewriter frame l3 and comprising two rearwardl'y extending: triangular plates 56 secured to the rear. portion of the main typewriter frame 13.

The: rod. 43 at-the back. of the carriage Ill ex.- tendsthroughholes 58 provided in the peripheral flanges 4-1 of. the carriage. extension 45, and the movement of the latter upon the rod 4.8 islimited by collars 65. fastened upon the rod, one at. each lateral side of the extension in slightly spaced relationthereto. The. extension 45 is resiliently carried along. by the. carriagev by means of two springs 51-, each spring having one end secured to a stud 6.8 onthe rod. 48 and having another end secured tothe underside of the carriage extension 45. The. springs 6;! extend in oppositev directions from the stud 68 and are designed to urge the extension to assume a definite position with respect to the carriage while, however, permitting the extension 45 to lag momentarily behind the carriage during each letter-feed movement of the carriage. The typewriter carriage [0, therefore, letter feeds substantially without interference by the mass of the extension 45 and the parts carried thereby, and thus permits utmost typing speed. The collars forceably compel the carriage extension 45' to move with the carriage during long carriage advance and long carriage return movements. At the termination of such long movements, the springs 61 cushion the arrest of the extension.

A conventional carbon carrier unit 69 comprises a truck plate II and a capping plate 12 overlying-the-truck late, the latter being secured upon the formerin a readily detachable manner, not shown, but conventional in Underwood fanfold machines. The truck plate H has at each lateral end a, pair of. grooved rollers 13 engaging the outer edges. of parallel trackwaysllthe latter extending along the left and right border of the carriage extension 45. The capping late 12 has fastened upon each of its lateral end a stepped bracket 15', and attached to these brackets are blades 16 whereto carbon sheets 8! are attached in a conventional manner, see Figures 3 and. 4..

Referringfnow to Figures 1 and. 3, the, work web 83 is supplied upwardly from the rear of the machine over a guide bar 11 and extends forwardly over the carriage extension 45 and downwardly around to the front of the platen 2|. The case shift (frame .II'I supports a usual paper apron 32, and the displaceable sub-frame l8 has a paper table 84 extending tangentially from the upper front portion of the platen 21, as seen in Figures 1,2 and 3. A form severing knife 85 is also carried by the sub-frame I8, see Figures 1, 3 and 4. The work webv 83 may comprise several plies 86 and the carbon sheets 8| extend forwardly from their supporting blades 16 in inter.- leaved relation with the plies, the leading ends of the carbon sheets being'normally about inch portion of a power actuable carriage return and line-spacing mechanism which may substantially correspond to the patent to Pitman No. 1,679,- 741,. dated August'l, 1928, and which may include a rack 9| limitedly slidable on the carriage ill, in a manner not shown. The rack 5| is geared to a power rotatable pinion 92, which, when power rotated, advances said rack. 9| in. carriage return direction, first to line space the. platen 2| and thereafter to return the carriage. The pinion 32 has clutch teeth 93. normally disengaged from a clutch member 94 that may be continuously driven by a motor through intermediate transmission members that may comprise a shaft 91 and a worm gear drive 98, see Figure 9. To effect a line spacing and a carriage returning operation, it is merely necessary that the pinion 92 be shifted to engage its teeth 93 with the clutch member 94. This, as is evident from said abovementioned Pitman patent, may occur responsive to depressing a carriag return key, or responsive to the carriage reaching a definite position in its advance.

The carbon sheets are shifted from time to time to register with the succeeding forms to be typed upon. This is preferably done with the web in a straightened position so that the web plies will not bind the carbons. desired to shift the carbons 8| to register with a set of succeeding forms, the latches 3| are first moved clear of the pins 34 and thereafter the sub-frame is swung upwardly and forwardly to raise the platen 2i above the general plane of the carriage extension 45. See Figure 4. In the embodiment of the invention shown, means are provided to effect this by a single continuous motion of the operators hand. More particularly, as seen in Figure 2, a bar IIII supporting an adjustable paper-gage I02 is limitedly displaceable in a forward direction upon said sub-frame I8; and when so displaced, causes the latch arms 3| to be moved clear of the pins 34. Continued forward movement of the gage bar IIlI displaces the sub-frame l 8 about its pivot studs 28. Viewing Figure 1, it can be seen that the gage bar IIJI is fastened between the ends of the carriage to a pivoted shaft I03 extending toward the right end of the sub-frame J8, whereat, see Figure 2, the shaft I03 carries fixedly an arm I04. rackets I05 secured to the back of the bar 25 provide pivotal supports for the shaft I03, and a spring, not shown, urges the gage-carrying bar I!!! to normally occupy the position seen in Figures 1, 2 and 3 against an abutment, not shown. As seen in Figure 2, the arm I94 extends normally rearwardly from the shaft I03 and carries a pawl member III. This member III is engageable with a pin III) on one of the latch arms 3| to swing the latter, together with the other latch arm 3|, rearwardly when the gage bar IIJI is given an initial forward motion. During continued forward motion, the gage bar If lifts the subframe I8 by engaging the bar 25 thereon, so that finally the sub-Lframe comes to rest upon the forward part'of the main carriage-frame I6. The gage bar NH and the sub-frame I8 will then occupy substantially the position illustrated in Figure 4, it being noted that the gage bar may reassume its normal position with respect to the dlsplaceable frame I8, sometime during the displacement of the latter. The distance from the edge of the knife 85 to the gage I02 is equal tothe length of the forms used and, to bring the carbOl'ls into register with succeeding forms, the carbons are retracted relatively to the web a distance equal to a single [form length. This is accomplished byadvancement of the work web 83 against said paper gage I02 accompanied by the shift of the carbon carrier unit 69 against the stop 88. The work web 83 is preferably advanced against said gage I 52 incidental to moving the gage bar I!!! forwardly to raise the subframe I8. To this end, the operator lightly pinches the leading end of the web plies 861 and the gage bar IIlI between the thumb and index finger and swings the gage bar IilI forwardly while also sliding the fingers along the gage bar to advance the leading ends of the plies to the gage I02.

Power retraction of carbon carrier Normally ineffective power retracting means are rovided for said carrier unit 69, which means are preferably rendered effective incidental to Accordingly, when it is displacingthe said gage bar II to raise the subframe I8. Directing attention more particularly to Figures 6 to 12, this power retracting means will now be described.

Upon the underside of the carriage extension 45, there is mounted a drum I I5, capable of driving a belt or its equivalent H6 for retracting the carbon carrier unit 69. The belt H6, according to the embodiment of the invention shown, is attached at Hi to a bracket H8 reaching downwardly from said carbon carrier truck plate H, and extends from said point of attachment oppositely fore and aft onto a front pulley I2I and a rear pulley I22 from which pulleys the belt is directed oppositely onto the drum H5. In order to associate the belt positively with the drum,'the belt has two ends which are oppositely wound upon the drum, one above the other; the drum,

for this purpose, being at least double the width of the belt. From the foregoing, it will be evident that opposite rotational motions ofthe drum H5 will result in opposite directional movements of the belt I I6, and consequently, the carbon carrier unit 69. The drum I I5 is lightly constructed and may consist of the two spaced sheet-metal flanges I23 seen in Figure 7, joined by the thin hollow cylinder E24 seen in Figure 8. The cylinder I24 is slotted at I25 for admittance of the opposite ends of the belt within the hollow cylinder onto anyone of several anchorage pins I26 carried by one of the flanges I23. The entire drum H5 is rotatably mounted upon a short arbor I21 and a spiral spring I28 situated between the drum flanges I23 has one end anchored to the arbor and another end anchored to any one of several ears I3 I, the ears being bent at right angles from one of the drum flanges and forming, together with the flanges I23, a cage within which the.

spiral spring I 28 is so mounted and tensioned that the drum H5 urges the belt to advance the carbon carrier 69. Preferably, the tension of the spring I28 is such as to counterbalance the drag of the paper web and also the inertia and friction of the carbon carrier 69 which normally opposes forward movement of the carbon carrier. In other words, the spring is so tensioned that the carbon carrier will move forwardly upon the least application of force. For rendering the spring I28 conveniently adjustable for different weights of carbon carriers and webs, the short arbor i 21 is rotatable in upper and lower bracket plates 38 and MI, respectively and has an integral spiral gear I32 whereby it is rotatable through a worm shaft I33 which is provided with a knob I45.

The upper bracket plate E33 is mounted upon studs I42 which are fixed and reaching upwardly from-the lower bracket plate I4 I, the latter being fastened to the underside of the carriage extension through the medium of spacing studs I43. Bent down from the upper bracket plate I38 are front and rear ears 44 wherein the said worm shaft #33 is rotatably supported. As may be seen in Figure l. the upper bracket plate is situated in one of the openings 46 of the table 45, and the worm shaft turning knob I45 is easily accessible for effecting adjustments to the spring I28.

The rear pulley M2 is pivoted on a headed stud I34 secured to a block I35 provided on the under- 1 side of the carriage extension or table 45, while :From; time to time it is desired to retract the carbons: 8.! with respect to the work web 83, as inpreparation for typing upon a new form; and, in order to accomplish this expeditiously as well asefficientl-y, the aforesaid motor 95, aside from being capable to return the carriage Ill, also is adapted to rotate the said belt'drum M to retract the carbon unit 89. To this end, the motor shaft 91 is extended rightwardly from the worm gear drive 98 and carries a transmission pulley I46 which, through the medium of an endless belt M1, drives a pulley I48. A Shaft I5I extending parallelly to the carriage I 9, revolves unitarily with said pulley M8 and has splined thereupon a sleeve in the form of a clutch member I52 which is adapted to partake in the carriage movements by sliding along the said shaft I5I. The shaft I5I is preferably of square cross section and the clutch member I52, in order to slide with the least resistance along the shaft I 5|, may have rollers I53 engaging the four flat sides of the shaft. See Figure 9. During the movements of the carriage I0, the clutch member I52 is caused to move unitarily with the carriage through a clutch shifting element I54 which is pivotally carried on the lower bracket plate MI but normally held stationary with respect thereto, against a dog I56, by a contractile spring I51, see Figure 11. Leftwardly of the clutch member I52 and. coaxial therewith is another clutch member I58 comprising a gear I6I which is in constant mesh with a ear ring I62 fixedly carried by; the lower flange I29 of the belt drive drum H5. The clutch members I58 and I52 have normally disassociated clutch teeth I 64 facing toward 1 each other. Directing attention to Figure 9, it will-be seen that the member I58 is rotatably v carried upon a hollow stud I65 which'is secured at I68 to a right angularly bent bracket I81 riveted to the underside of the bracket plate I4I asat I68. An enlarged portion In of the stud cooperates with the bracket 581, to confine the rotary member I58 to move with the carriage extension 45. The square shaft I5! passes through the hollow stud, and has preferably some clear- 1.

adapted to be brought into clutching engagement inany position of the carriage. Supporting the shaft I5I may be a bracket structure comprising two bars I12, one in front and one in back of the shaft I5I", both extending parallelly to the carriage, the bars being fastened by screws I13 to the framework plates 56 and carrying at each end a hanger I14 for supporting the shaft I5I. The shaft may have a reduced end pivoted in the. left hanger; and, at the right, the shaft may be pivoted in a bearing I15 screwed into the,

hanger I14. and projecting outwardly therefrom. To relieve stress upon the shaft IN, the pulley I48 may run upon the said projecting bearing H5. The pulley I48 has a hub I15 into which the square shaft I5I fits and the pulley may be prevented from slippingofi the shaft by a pin I19. A collar I11 may cooperate with the pulley I48 .to,v retain the shaft I5I against lateral movement. It should be understood that the shaft I5I is of sufiicient length to allow full range travel of the typewriter carriage proper.

typewriter carriage I 0. Although the shaft I5I, according to the preferred embodiment ofthe invention, revolves continuously, the clutch member I58 is normally free to revolve, as, for example, during advancement of the carbon carrier caused by turning the platen 2I.

I62, and, therefore, also the drum, commence to be driven by themotor 95, resulting in the retraction of the carbon carrier 69 through the operation of the belt I I8.

Although the dog I56 may be operated in any suitable manner, this is preferably done as an incident tothe displacement of the platen subframe I8 through a mechanism presently to be described. with more particular reference to Figures 3, 4, 11 and 12. Adjacent the left end ofthe displaceable sub-frame I8, see Figure 3, just leftwardly of the gear 43, is a finger I18 embracing one of the sub-frame pivoting studs 28 and having an upper end secured to the left sub-frame end-piece 24. The finger I18 is unitarily displaceable with the sub-frame I8 about the pivot stud 28 and has, at a point below and rearward of the stud 28, a link I8I connected thereto. The link I8I extends rearwardly and is articulated at its rear end to a horizontally disposed arm I82 comprising part of a bell crank structure which further comprises a vertical shaft I83 and a lower, rearwardly extending arm I84. The shaft I83 pivots in an upright bushing I85 fixed upon the left bracket 5| extending rearwardly from the Articulated to and reaching rightwardly from the arm I 84, is a link I88 which is capable of operating a parallel motion linkage comprising two spaced arms I81 and connecting link I88 for said arms, the latter having a slot I9I extending in parallelism with the carriage Ill. The arms I81are pivoted at two spaced points I92 to the underside of a bar I93 which is rigidly carried by the rod 448 through the'medium of blocks I94. A dog controlling element I95 pivoted on the bracket plate II has an upright pin I98 located in the link slot I9I and another pin I91 is adapted to release the dog I56 from the aforesaid clutch shifting element I54 whenever the platen sub-frame I8 is being displaced. Itshould be observed at this point, that the link I88 with it's slot I9I affords an operating connection for said dog controlling element I95 which is operative irrespective of the position of the carriage extension 45 with respect to the carriage proper I8.- Whenever the platen is displaced to. the-position seen in Figure 4, the link I8I receives an initial slight rearward movement, and thereafter a forward movement of greater magnitude. The initial slight rearward movement of the link I8I is of an idle nature in thatit has no influence whatever on the dog I56.

The final forward movement of the link I8I, as

brought about by the sub-frame I8 approaching the displaced position seen in Figure 4, results in a bodily forward displacement of the slotted link I88; and this, in turn, results in a clockwise pivotal displacement of the element I95. Following the operation further, the pin I91 on the element I95 displaces the dog I56 forwardly about its pivot and clear of the clutch shifting element I54, thus allowing the latter to move to closed clutch position 'under the power of its spring I51, see Figure 12. As heretofore made clear, the platen sub-frame I8 is unlocked and displaced in a single operation by swinging the paper gage IIJI forwardly. From this it will be seen that no special attention is required of the operator to render the carbon retracting device effective. After the clutch members I52 and I58 have been engaged, the belt H6 drives the carbon carrier 69 rearwardly until the latter finally engages the aforementioned stop 88 which is adjustably mounted on a straight bar 20I arranged underneath and in parallelism with the direction of movement of the carbon carrier 69. The bar '20I is mounted at opposite ends by pin-and-slot connections 202 upon the carriage extension 45. Reaching downwardly from the bar 2M through one of the openings 46 in the carriage extension is an ear 2B3 whereto a forwardly extending wire link 204 is connected. The forward end of this link is articulated to a leftward branch 295 of the clutch shifting element I54. In the open clutch position of the latter element, the bar 2M lies in a rearward position,-as may be seen in Figures 6 and 11; but whenever the clutch shifting element I54 occupies a closed clutch position, the bar has considerable capacity for rearward movement. As seen in Figure 10, the carrier 69 being power m-oved rearwardly engages and moves the stop 88, together with the bar 2M and the wire link 204 rearwardly, the latter swinging the clutch shifting element I54 to open the clutch; consequently, the power retraction of the carrier 69 is automatically terminated. As at the conclusion of the power retracting operation, the platen may still be in a displaced position, it is conceived to provide a secondary dog 2136 which, incidental to the displacement of the platen subframe I8, is automatically conditioned to detain the clutch shifting element I54 against closing movement after being moved to open clutch position. A tail 2 on the pivoted member I95 normally holds the secondary dog 206 clear of the branch 205 of the clutch shifting element. This tail moves leftwardly during the displacement of the platen and the spring 209 then, as far as the tail 2| I is concerned, may swing the secondary dog 2 06 rightwardly. The normal position of the clutch shifting element I54, however, is such that the secondary dog-206 can only swing to holding position in consequence of a clutch opening movement of the shifter I54 somewhat beyond the normal position, as efiected by the retraction of the carbon carrier 69, see Figure 9.

Subsequent ,to the retraction of the carbon sheets 8! and after the work web 83 has been advanced against the gage I02, the operator restores the platen ID to typing position and severs the typed set of forms by tearing it against the knife 85. A new set of forms is then ready to be typed upon. Incidental to the restoration of the platen sub-frame I8, the parts IN to I84, 88 to I88 and I95 assume their normal positions seen in Figure 11, so that the said dog I56, which may be termed a primary dog, is free from restraint by the pin I91; and, under the tension of a spring 201, readily assumes its normal effective position against a stop pin 258 to block the clutch shifting element I54 against clutch closing movement. Also incidental to the restoration of the sub-frame I8, but a little later, the secondary dog 206 is forced from efiective position by the tail 2 of the pivoted member I95. It will be evident, from an inspection of Figure 10, that the secondary dog 2B6 detains the clutch shifting element I54 in a position wherein the primary dog I56 will not be obstructed against movement to .efiective position. From the foregoing, it should be understood that only one carbon retracting operation can result in response to each displacement of the platen sub-frame I8.

The operator mayrestore the platen sub-frame before the retraction of the carbon carrier is fully accomplished, and, to prevent rupture of the carbon sheets, which in such an event would become pinched and held against retraction between the feed rolls 2t, 21, and the platen, it is highly desirable to terminate the power retraction of the carrier as the platen is being restored to typing position. With this in mind, and with particular reference to Figs. 3, 4, and 12, it will be seen that the clutch-shifting element I54 is adapted to be imparted a clutch-opening movement through a restoration of the dog-controlling element i brought about by the restoration of the platen to writing position. More specifically stated, as the point of articulation of the link IBI with the sub-frame sweeps towards the rearward extremity of its moving path, the pin I91 will have moved the clutch-smrting element I54 to an open-clutch position, sufliclently far to allow the primary dog I55 to reassume control thereover and hold it in open-clutch position pending a new displacement of the platen from writing position. Also it may be observed from Figure 11, in conjunction with Figure 3, that the pin i9? recedes from the clutch-snirtlngelement I54 when the platen approaches fully restored position. This is because the point of articulation of the link ml with the left end piece 24 of the platen sub-frame l8 sweeps past a real-most point with the result that the link IIII, and consequently also the pm Isl, is given a slight forward movement just before the said sub-frame reaches the position seen in Figure 3.

The carbon carrier I55 moves rearwardly at considerable speed and, in order to check rebounding of the carrier from the stop 88, it is conceived to provide automatically responsive v means to check the carrier 59 transltorily against advancement following retraction. One embodiment such means may take will now be described with special rererence to F gures 6, 10 and 13.

A bell crank 2I2 is pivoted at 2I3 to the carbon-carrier truck plate ii and consists of a hook-shaped arm 2M and a laterally extending arm 2l5, the latter having pivotally connected thereto a rearwardly extending slide 2I6. Articulated to the hook-shaped arm 2M and located to the right thereof is an air dash pot device comprislng'a piston rod 2|! pivoted at 2I8 to the arm 2M, a piston 22I rigidly attached to the right end of the piston rod ZI], and a cylinder 01' sleeve 222 which is closed at the right-hand end, except for the provision of a small vent 223. See Figure 13. The sleeve 222 is pivotally mounted on a stud 224 secured to and protecting downwardly from the truck plate ll; and it should be understood that the sleeve aligns itself freely with the angular position of the piston and piston rod as varied by the swinging movement of the arm 2I2. The slide 2W is guided for fore-and-aft movement and for this purpose has a pin-and-slot connection 225 with the truck plate II. The pin-and-slot connection normally limits rearward movement of the slide 2I6, such movement being efiected by the power of a light spring 226 that is attached tothe arm 2M and anchored to the truck plate I I. When in normal position, the slide 2H5 extends rearwardly from the truck plate H. The piston 22| fits the sleeve loosely and carries a pump washer 22'! which readily collapses when the piston movesleftwardly, but which provides an efiective seal for the piston when moved rightwardly. It follows,

therefore, that the dash pot device functions only when the piston is moved rightwardly, i. c. it functions to delay only the restoration of the arm. The various parts ofthe rebound checkin means normally occupy the positions seen in Figure 6 and it will be observed from this figure that the hook-shaped arm M2 is normally free to move rearwardly with the carbon carrier, without encountering a catch plate 228 which in a forwardly extending relation is attached to the stop 88. ward movement of the carrier 69, the slide 2 l 6 engages the stop 88 and is displaced forwardly with respect to the carrier 69. The slide 2|! being connected to the bell crank M2, the hook-. shaped arm swings backwardly of thelug 223 on v the catch plate 228. -Substantially concomitantly the power retraction of the carrier is terminated, that is, theclutch members I52, I58 become separated and the carrier rebounds forwardlyiromrthe stop 88. Thehook-shapedarm 2! then temporarily checks rebounding of the carrier by its engagement with the said lug 229.

' After a certain time interval, as is definitely con- The stop 88 is adjustable along the bar 201 to variously control the positions to which the carbon carrier is retractable, The bar 20! is preferably of. light stock; and, in order to counteract flexing thereof, it may be confined on the carbon carrier between the slide2l6 and a roller '23l The motor 95, according to the diagram of Figure 15,, need not be continuously running. More specifically, a pair of contact fingers -232 may be included in the motor circuit 233 and may respectively be closed and opened through a link 236, by the clutch-closing and clutchopening movements of the clutch shifting element I54. A motor switch 234 may also be provided for energizing the motor to eifect carriage returns, and may be controlled in accordance with said aforesaid patent to Pitman.

What is claimedis:

. 1. In a writing machine having a frame, a carriage movable on said frame, and a writing support relativelyto which carbon sheets .are retractable on saidcarriage; a motor on said frame, a shaft element disposed in parallel with the direction of movement of the carriage, an element slidably splined to said shaft element, one of said elements being on said frame and rotatable by said motor, and the other of said elements being supported for movement withsaid carriage, means on the carriage operable to retract said carbon sheets, and includinga member that :is

coaxial with said other-element, but normally,

revolvable independently thereof, and means to operatively connect said last-mentioned element During the last portion of the rear-- and said member in. any position of the carriage, to cause thereby motor operation of the said operable means,

2. In a writing machine havingv a frame, a carriage movable on said frame, and a writing support relatively to which carbon sheets are retractable on said carriage; a shaft extending in parallelto the direction of movement of the carriage and being rotatably supported at two spaced locations on said frame, motor drive means to rotate said shaft, an element slidably splined to said shaft for movement along. said shaft with said carriage, carriage supported carbon-sheet retracting means, normally disassociated operatively from said element, and means to shift said element axially on said shaft into driving association with said carbon-sheet retracting means for operating the latter.

'3; The combination with -'a writing machine having, a carriage movable on a frame and a carbon carrier on the carriage retractable from a writingsupport, of means on the carriage operable to retract said carrier, motor drive means to operate said retracting means, including a frame-supported shaft exten'ding in parallel with the directionof movementof the carriage, and a clutch element 'slidably splined to the said shaft for movement with said carriage, said retracting means including a clutch element companion to the said first 'clutch element, and means to render the said first clutch elem'ent operativel'y connected or disconnected from the other clutch element in any position of the carriage;

4. In combination with -a writing machine having-a carriagemovablefon a frame "and a carbon carrier on the carriage retractable from a writing support; a belt drive on said carriage f'or retracting "said carrier, including, a belt "operatively connected with said carrier, "and a belt moving drum rotatable on a substantially vertical axis; and means to rotate said drum by power, comprising, a motor on the frame, a shaftmember "extendingin parallel with the direction of movement of the carriage, a member slidably splined to said shaft-member, connecting 'means between one of .said members-and said motor, and means to drive said drumby theothe'r oneoi said members, includingagear o'nsaid carriage, rotatable coaxially with said other member, and

a gear on said dru'm meshing said first-gear;

5. In a writing machine having "a retractable carbon carrier, power=retracting mean's for said carrier, including a normally open'driveconnection, shifting means foropeningand closing said drive connection, including means whereby the drive connection is biased=to close,'means adapted to hold said shifting means in open drive positionupon movement thereto, said holding means being normally efiective,meansoperable and restorable, respectively, to disable and enable :said holding means, means operative upon the retraction of saidcarrier to a certain .position to move said shifting means to open drive position, and normally-inefiective means adapted to detain said shiftab-le means upon drive'opening movement while said holding 5 means remains disabled.

6. In a writing machine having a retractable carboncarrierya device operable to retractsaid carrier, power means for operating said device, means movable to and-'fr'om'an operated F position to render said power-means respectively-effective and ineffective to operate Said device,said m-ovable means being-biased toward operated position,; a primary dog normallychecking -said -movable means -against operation,- control means actuable to release said primary dog and consequently render said power means eiiective to operate said device, means, responsiveto the retraction of said carrier, torestore said movable means, a secondary dog, rendered efiective by the actuation of said control means to check reoperation of said movable means, following restoration, said control means when being restored rendering said primary dog effective and said secondary dog ineffective, said dogs being so arranged that the primary dog will check said movable mean against operation following the restoration of said control means. 7

7. In a writing machine having a platen with respect to which carbon sheets are retractable; a motor, carbon-sheet retracting means operable by said motor and including normally open drive means adapted to be closed to render the carbonsheet retracting means efiective, means mounting said platen for movement to and from a writing position, and mean for rendering said drive means closed in response to movement of the platen from writing position, and for rendering it open either in response to movement of the platen toward writing position or in response to the carbon sheets being power-retracted to a certain position.

8. In a writing machine having a platen and a retractable carbon-sheet-carrier; means for mounting said platen for movement from and restoration to a writing position, normally ineffective power-retracting means for said carbon carrier, including normally open drive-means which are closable to render the power-retracting means effective, means biasing said drive-means to close, holding means normally in control over said drive-means to hold it open, means operative upon said holding means incidental to movement of said platen from writing position to cause closure of said drive-means by said biased means and thereby to render the power-retracting means effective, and means for opening said drive-means either responsive to the retraction of said carrier to a certain position or responsive to the restoration of said platen to writing position, said holding means being so constructed and controlled that responsive to each opening of said drive-mean the latter will be held open pending a new movement of the platen from writing position.

9. In a writing machine having acarbon carrier advanceable and retractable from a writing support; belt-drive means associated with said carrier for advancing or retracting it, said drive means including, a ,drum, and a belt, said belt being operatively connected with said carrier and positively movable by said drum to either advance or retract said carrier; and spring means exerting normally a carbon carrier advancing influence upon said drum.

10. In a writing machine having a carbon carrier advanceable and retractable from a writing support; belt-drive means associated with said carrier for advancing or retracting it, said drive means comprising, a drum, a belt and means to guide a portion of said belt along the moving path of said carbon carrier, said belt being associated for positive movement by the drum to either advance or retract said carrier; spring means exerting normally a carbon carrier advancing influence upon said drum; and means conditionable to power-operate said drum to retract said carbon carrier.

11. In' a writing machine having a carbon carrier advanceable and retractable from a writing support, a drive associated with said carrier for advancing and retracting it including an element rotatable in one direction to cause advance of the carrier, and rotatable in opposite direction to cause retraction of said carrier, power means exerting normally a carbon-carrier-advancinginfluence upon said element, normally ineffectively conditioned other power means adapted to rotate said element into said opposite direction, in opposition to the said first power means and means for efiectively conditioning the last said power means.

12. In a writing machine having a carbon carrier advanceable and retractable from a writing support, a belt drive for retracting said carrier, comprising, a drum, pulley means, and a belt having opposite ends anchored and wound oppositely on said drum, said belt passing over said pulley means, and said pulley means guiding a portion of said belt along the moving path of said carrier, means operatively associating said belt with said carrier for retracting it, and means normally exerting a carbon-carrier-advancing influence on said drum.

13. In a writing machine having a carbon carrier advanceable and retractable from a writing support, a belt drive for retracting said carrier, comprising, a drum, two guide pulleys spaced in the direction of the movement of the carrier, and a belt having opposite ends anchored and Wound oppositely on said drum and having a loop stretched over said guide pulleys, wherefore a portion of said belt extends along the moving path or" said carrier, means for supporting said pulleys including a device urging one of said pulleys from the other to keep the belt taut, and means operatively associating said belt with said carrier for retracting it.

14. In a writing machine, a transversely movable carriage, a platen on the carriage, a table, means for supporting and guiding said table in parallel with the direction of carriage movement, means resiliently connecting said table for movement by the carriage so as to allow the table to lag behind the carriage during carriage movements, a carbon-sheet carrier on said table retractable from said platen transversely to the direction of carriage movement, normally ineffectively conditioned motor means adapted to retract said carriage, said motor means including a normally open drive connection on said table in close proximity to the platen carriage, means to displace said platen, and a drive connection controlling mechanism responsive to the displacement of said platen to close said drive connection to render thereby said motor means effective, and responsive to the retraction of said carrier to open said drive connection and to render thereby said motor means ineffective, said controlling mechanism including, a member supported solely on the carriage and operated as an incident to the displacement of the platen, and a member supported solely on the table, said members being constructed and arranged, the former for operation directly by the latter, always to the same extent, irrespective of the variable position of said table with respect to the carriage.

15. In combination with an advanceable carbon-carrier that is l-imitedly retractable, a device operable to check rebounding advance of the carbon carrier, said device being characterized by a tendency toward ineffective condition, means to operate said device as an incident to the retraction of said carrier to render the device effective as a rebound check, and means for controlling said device to maintain it "effective until the rebounding of the carbon carrier has been checked and thereupon render it automatically inefiective.

16. In combination with an advanc'eable carbon carrier which isilimited1y.retractive, a device operable and restorable respectively to check rebounding advance of the carrier and to free i said carrier for advance, means biasingsaid deagsvaava 17. "In combination with an advanceab'le cal bon carrier which is limitedly retractable, a device operable andrestorable, respectively to check rebounding of the carbon carrier and to allow advance of the carboncarrier, means to limit carbon carrier retractionandto cause incidental to limiting the retraction an automatic operation of said device, thereby to render said device effective for rebound checking, and restoration effecting and controlling means for said device constructed to respond automatically but hesitatingly to the operation of said device, so that the latter will automatically allow advance of said carbon carrier, but onlyafter rebounding of the carrier has been checked.