US953988A - Shifting device. - Google Patents

Description

H. DREWELL.

` SHIFTING DEVICE. APrLIoATIoN FILED JUNE 2 6, 190s.

Nro/q '9 H. DREWELL. SHIPTING DEVICE APPLICATION IEILBD JUNE 26,1908.

Patented Apr. 5, 1910.

Pateted Apr. 5, 1910.

4 SHEETS-SHEET 3.

H. DREWELL. SHIPTING DEVICE. APPLICATION FILED JUNE 26,1908.

W( TIYES Sf'J v H. DREWELL.

SHIPTING DEVICE. APPLIoA'rIo'N :FILED JUNE 2e, 190B.

Patented Apr. 5, 191.0.

4 SHEETS-SHEET' 4.

HEINRICH DREWELL, F CHARLOTTENBURG, GRMANY, ASSIGNOR T0 SCHNELLSETZ- MASCHINNGESELLSCHAFT MIT BESCHRNKTER HAFTUNG, 0F BERLIN. GERMANY.

" SHIFTING DEVICE.

Specification of Letters Patent.

Patented Apr. 5, 1910.

Application filed June 26,1908. Serial No. 440,589.-

To all 'w'hom 'it may concern:

Be it known that I, HEINRICH DREWELL,

subject of the German Emperor, residing at Charlottenburg, near Berlin, Germany, have invented new and useful Improvements in Shifting Devices. of which the following is A a. specification.

This invention relates to shifting devices such as are employed in typewriters, type space indicators, line justifying devices, band perforating mechanisms and thelike.

Shifting devices known hitherto for shifting the paper carriage of typewriters and the like different distances depend, generally speaking, on a. pawl beingoperated when a. key is depressed. This pawl is then placed against movable stops. Each time a key is depressed one of these stops is brought into the path of the pawls. According to the breadth of the letter which correspondsV to the key which is struck, the stop brought in the path of the pawl is at a different distance from the normal position ofthe pawl. In this manner the part to be shifted is moved correspondingly each time. Such devices, however, have the disadvantage that the individual members which come into op#` eration .very easily get out of order. For. 1n orderto shift the paper carriage as'rapldly as possible,the movable parts of the shifting device must be made as light possible. Therefore even only slight wear4 and tear causes defective working. on account of bent parts and other defects. This is made still worse by toothed wheels and racksv being necessary for shifting dii'erent degrees. the pitch of whichlwheels and racksl must correspond to t-he smallest possible dierence of two extents of shifting which are used. Also acomparatively large number of single parts are required in order to obtain a suitable number-of steps, because a special stop has to be adjusted for each step, and,

4 moreover, the movable pawls controlling the extents of shifting have to be released.

Now an important object of the .present invention is to do away with these defects.

Thefundamental idea o f the invention does not consist in one single pawl and ratchet mechanism with dilierent extents of shifting being used as i-n known shifting devices, but in providing a plurality of pawl' and ratchetmechanisms acting independently one of another and each having one singlev extent of shifting. This independence -1s -ratchet mechanisms.

ratchet mechanism being transmitted by one central member to the paper carriage. yThis centra] member makes movements which are dependent on two or more-different pawl and The amount of the movement of the central member results from the summation of the movements made by the individual pawl and ratchet mechanisms. Thus two pawl and ratchet mechanisms give three different extents of shifting. Vhen more than two pawl and ratchet mechanisms are employed, an opt-ionally large number of extents of shifting is obtained corresponding to the number of the possible combinations of the individual mechanisms In order that the invention may be clearly understood,reference is made to the accompanying drawings in which a plurality of embodiments are represented by way of example, and in whichz- Figure l is a vertical sectional elevation lof one form having two pawl and ratchet mechanisms and one differential gear Fig. 2 is a horizontal section showing partI of the device according to Fig. l; Fig. 3 is an elevationof a modified form of part of the apparatus according to F l, four pawl and ratchet mechanisms being shown; Fig. l lis a vertical sectional elevation of an apparatus of simplified form as compared with that shown in Fig. l; Fig. 5 is a horizontal section showing part of the apparatus according to Fig. 4, and F ig. 6 is a plan, as seen from below, showing a detail of the device according to Fig. 4; Fig. 7 is an elevationshowing a modified form of part of the device according to Fig. 4, this being a moditied form of the detail according to Fig. 3.

The invention isrepresented in the above described figures as applied to a typewriter according to the Underwood system. but it is clear Vthat the invention can also be employed in 'all other corresponding typewriters and4 machines which are used for vsimilar purposes, as. for example, in apparatus for making register bands for controlling type setting machines and the like.

vReferring to the drawing, in the f rm according to Figs. 1 to 3, 1 is the frame of vthe machine, 2 the paper carriage, 3 .the

platen roll, and l, and -G are lguide wheels for the paper carriage. Under the wheel 6 is arranged the rail T by means of which ico other hand, prevent these parts being moved the platen 3 can be raised for the purpose l of changing to a different sort of type.

9 is the key by depressing which the keylever 10 is moved. The latter has its fulcrum at 8 in the frame of the machine. A spring 11 normally presses the lever 10 upward. pin 12 attached to this lever 10 engages i'n the slot 13 of a bell-crank lever 15 which is mounted at 14. On the bellcrank lever 15 there is a pin 16. This engages in the slot- 17 ot the type-lever 18. The latter' is pivoted at 19 and carries on its end the type-bar 20. Further, on the frame 2 ot the paper carriage there is attached the rack 25 iu which a pinion 26 engages. The purpose of this pinion is to move the` frame of the paper carriage farther on and consequently to bring into operation the arrangement Jforming the subject-matter of the present invention. The axle 27 of this toothed wheel is revoluble in bearings 28 and 29 in the frame of the machine. The axle 27 carries a ring 30 carrying two pivots 31 and These pivots carry the bevel wheels 33 and 34 which can rotate around the two pivots as axles. Further, below and above the ring 30 there are arranged in addition the two bevel wheels 35 and 36 which on their part are tirmly connected with the two ratchet wheels 21 and 22. Theipreviously mentioned ring 30 on the one hand, and two regulating rings 23 and 24 on the in an axial direction. The four bevel wheels 33, 34, 35, 36 :torni a differential gear. The n'iovement of the two outside wheels and 34 is determined by the motion which is imparted to the wheels 35 and 36 by means of the ratchet wheels 21 and 22 in the manner which will now be explained. Pawl and ratchet mechanisms are used yfor this. Each of these consists of two pawls which can both -be displaced in the direction of the axle 27 and which alternately engage with or disengage from the wheels 21 and 22. I

The shitting mechanism of the wheel 21 :onsists of the two pawls 40 and 41. The pawl 40 is formed by a tooth arranged fixed in the plate 42, whereas the pawl 41 is the endof a lever 43. The latter is revoluble on the stem of a screw 44 inserted inthe plate 42. The lever 43 moves between two stops 4.5 and 46 and carries a pin 47. A spring 48 is attached to the latter .and tends to place the lever 43 against the `stop 45. The driving spring of the paper carriage which is not represented in the drawing acts against this spring 48 in suchiluanner that it tends to rotate the wheel 21 in the direction of the arrow 53. (Fig. 2.) The plate 42 is rigidly attached to .the rod or axle 49 ot a feeding frame which is formed' in addition of the end members 50 and 51 and the rod 52. Another pawl and ratchet the pawl 40 moves downward into mechanism acts on the wheel 22 in the same i manner as on the wheel 21; this mechanism consists of the plate 54 with the tooth 55, the lever 56, screw 57 and the other corresponding parts. The latel 54 is attached on the axle 59 of a feeding frame which consists in addition of the ends 60 and 61 and the rod 62. Vertical connecting rods 63 and 64 are attached to the ends of the rods 52 and 62. These connecting rods carry the universal bars 65 and 66 situated below the keys. Opposite these universal bars there are stops 67 and 68 on the key-levers 10. Vhen one of the keys 9 is depressed, that universal bar 65 and 66 is moved downward which is opposite to the corresponding stop 67 or 68 of the depressed key-lever 10. 1f the universal bars 65, for example, is moved downward by a corresponding key being depressed, the rod 52 follows this movement, the frame 52, 51,' 50 and 49 being rocked on the laxle 49. The plate 42 participates in this movement. Consequently a gap between the teeth of the wheel 21. The pawl 41 is disengaged from the wheel 21, so thatthis wheel is now locked by the pawl 40. As soon as the pawl 41 on the lever 43 is disengagedfrom the wheel 21, it follows the action of the spring 48 and moves about the width of one tooth in the direction opposite to that in which the wheel 21 rotates, until the lever 43 lies against the stop 45. When the key 9 is released, the bar 65 together with the frame 49, 50, 51', 52 is returned into its normal position by springs 37 and 38 which are attached to the plates 42 and 54, which plates are revoluble with the axles 49 and 59 respectively. The pawl 40 comes away from the ratchet wheel 21 and the pawl 41 engages in the same wheel. As the ratchet wheel 21 is now under the action ot' the driving spring of the paper carriage, it tends to -rotate a ainst the checking action of the pawl 41. @he pawl 41 now yields until the lever 43 lies against the stop 46, the wheel 21 having rotated about the angle given by one width of a tooth. The pawl and ratchet mechanism which is at the wheel 22 acts in the same manner as soon as the bar 66 is moved downward by pressure on a corresponding key.

` Instead ot the pawl and ratchet mechlanism here described any other form which is customary in typewriters may also be em- .n consequence of the toothed wheel 21 rotating, the bevel wheels 33 and 34 and the pivots 31 and 32 rotate around the axle 27 and, as long as the wheel 22 is stationary,

half the amount of the angle of rotation of the wheel 21. The same takes place when the pawl and ratchet. mechanism at the wheel 22 operates and the wheel 21 is stationary. The pitch of the two wheels 21 alsaess and 22 is entirely vindependent of one an; other, so that in this manner two entirely independent different exte'nts of 'shifting the paper carriage can be obtained. A third extent of shifting results from the two ratchet wheels 21 and 22 and their pawl mechanisms being able to be operated simultaneously. In4 this case the wheels 33 and 34 rotate` with the axle 27 an 'amount which is equal to the sum of half the angles of rotation of the two wheels 21 and 22, or, lwhich isthe same, to the arithmetical mean of these angles of rotation. This third rotatory movement is' thus dependent on the amount of the two others. The rotation of the axle 27 is transmitted` by the driving pinion 26 and the rack 25 to the paper car.

riage 2 and is converted into a motion of transmission. The latter motion thus corre spends constantly to the rotatory motion of one of the ratchet wheels21 and 22 when the latter isplaced. The bearings'28 and29 are not shown here. AThe axle 27 carries in its center a ring 30 which is provided with pivots 3l and 32. On the latter rotate the bevel wheels 33 -and34, withv which again bevel wheels 35 and 36v enga e. The latter however carry sleeves ,orvbus ies 69 .and'70. These latter `rota-te loosely onv the axle 27 and these bushes, as well as the parts connected with them, are prevented from being shifted-longitudinally of the axle by the fixed rings 23 and 24. v' Each of the bushes 69 and 70 carries two pivots 71, 72 and 73, 74 on which bevel wheels 75, 76 and 77, 78 rotate. Further, with the latter thereengage bevel wheels, namely 79 and 80 above, and 81 and 82 below. Eachof' the last mentioned four bevel wheels carries one .of the ratchet wheels 83, 84, 85, 86. Each individualratchet wheel can be switched by one of thepawl and ratchet mechanisms 87, 88, 89, 90 in optional manner corresponding to that described above. The ratchet wheels 83 and 86 are held in position by regulating rings 23 and 24'as shown in Fig. 1. IThe' manner in which this arrangementoperates is as follower-If one of the ratchet Wheels 83 or 84 1s moved on one tooth, the corresponding bevel wheel 75 or 76 `is rotated half the angle of rotation of the ratchet wheel. The

,bush 69 andthe bevel wheel 35 rotate simultaneously with the bevel wheels 7 5 orv 76 inthe same manner the bush 70 and the bevel wheel 36 rotate with the bevel wheels 77 and 78.v The `movement of the bevel or'36 rotates.

bevel wheel .33 and r34ZT and the pivots 31 and 32 of these wheels rotate with. the axle wheel 35 or 36follows the movement -of thel 27 half that amount which one of the wheels If one of the ratchet wheelsv83, 84, 85, 86 is rotated, the axle 27 rotates the fourth part of this amount. If two of the ratchet wheels, for example 83 and 84, are shifted, the angle .of rotation of the bush 69 is equal to half the sum of the angles of rotation of these two ratchet wheels, and the angle of rot-ation of the axle 27 is equal to half this half sum. If all four ratchet wheels are rotated, the angle of rotation of the axle 27 is equal to ,the fourth partof the angle of rotation of all the ratchet wheels. It follows from the above that in every case the angle of rotation of the axle 27 is equal tothe fourth part of the sum of the angles of rotation of all the ratchet wheel-s 83, 84, 85, 86, if it is taken into. consideration that the wheels, the pawl 4mechanisms of which are not moved, rotate an amount zero. The distances which the ,ratchet wheels 83, 84, 85, 86, are shifted are independent lof one another; thus four optional gradations can be obtained. Fun ther gradations are obtainedV by the'v optional combination of these distances of shifting. If the proportion of the vgradations is selected as 1:2 :4 :8, all distances of shifting from onejto fifteen units measured according vto optional units are obtained. Thus withthe aid of four ratchet wheels, fteen different gradations are possible. Since the very small distances, which in the 'above givencombination .would amount to one Aor two units, are not as a rule used in practice, it is consequently preferable to begin with a greater step, so that it is not necessary to make the ratchet wheels with too fine' teeth, Forv practical purposes, the widths of teeth 3, 4, 5, 6, for example, are

used, from which moreover the'following steps are obtained: 7, 8, 9, 10, 11, 12, 13, 14, 15 18. v

'aIhe above described shifting' devices are particularly adapted for employment 1n typewriters. y are preferably situated under the key-levers opposite the stops 67 and 68 on the latter.

In machines without a shift key, the universal bars cannot be displaced inthe longitudinal direction of the key-lever 10. Each 'lever 10 carries' one -or `two shoulders or stops 67, 68, according to the amount of shifting which is required, namely according to the .breadth ofthe character which it has to write.

vIn .machines with a shift key, generally speaking, .the characters combined von one type-lever are not equally broad when types of different Width are employed. An alteration in the extent f shifting corresponding to each leveris then required, as soon The universal bars l65 and 66 as the machine is changed to another character by pressing the shift key. For this purpose 4a device which is also represented in Figsl and 2 can be employed. VVi-th universal bars 65 and 66 in such manner that these universal bars are not prevented from moving downward, but are compelled to follow a lateral displacement of the guides 124 and 125. Thls lateral displacement. occurs as Soon as the shift key is pressed. The universal bars 65 and 66 are shifted parallel to their longitudinal direction so far that they are no longer opposite the stops 67 and 68, but are opposite a second row of stops 87 and 88. This second row of stops can be arranged optionally onthe key-levers 10 independently of the iirst row in such manner thatthe extent which the paper carriage is shifted by the individual levers 10 after the shift key is depressed is independent of that before the shift key is moved.

Figs. 4 to 6 represent another constructional form of the invention. -The same numerals as in Figs. 1 and 2 here denote the parts which are also shown in these gures. Here also there is attached on the frame 2 of the paper carriage a. rack 25 which isl moved by a pinion 26 on the axle 27. On the latter there is also a disk130. l This disk is specially represented with its appertaining parts in Fig. 6. On the disk there are arranged two pawls 131 and 132. These engage alternately in a. ratchet wheel 133, this alternation being brought about by an axial displacement of the wheel 133. Further, there is attached to the wheel 133 the sleeve or bush 134 which on its part carries another ratchet wheel 135. The latter is checked in its movements by pawl mechanism consisting of two pawls 137 and 138 which are revoluble around the pivot 136 (see particularly Fig. 5). The pawl 138 can also be displaced longitudinally on the pins 139 and 140, in addition to rotating around the pivot 136. In the normal position the pawl 138 engages in the wheel 136.

As soon as a key is depressed, the engagement of the pawls 137 and 138is changed,

` the pawl 137 entering into a gap in the teeth of the wheel 135 while the pawl 138 leaves the wheel. The latter pawl is now pulled back by a spring 141 so far that it does not engage in the same gap as before, when the engagement of the pawls changes again,but in a gap situated to the rear in the direction of rotation. Consequently the ratchet wheel 135 can rotate one tooth against the action of the spring 141. This wheel is rotated by the driving spring of the carriage, the pull of which is transmitted through the rack 25 and the pinion 26 to the axle 27, the disk 130, and further, by means of the pawls 131 and 132, to the wheels 133 and 135. Like- Wise the axle 27 can also be rotated by displacing the wheels 133 and 135 axially. During this displacement, the wheel 135 is held by the pawl 138, since this pawl is /so broad that it does not become disengaged from the wheel 135. The pawls 131 and 132, however, change in their engagement with the wheel 133. The pawl 131 (Fig. 6) is attached on a rod 129 011 the late 13() and cannot change its position wit 1 respect to the wheel 130. The pawl 132, on the contrary, is arranged on a plate 144 which is revoluble around the axle 27. The rotation of this plate is limited by two stops 145 and 14.6 which are attached to the disk 130. The play of the plate 144 between these stops is so great that the pawl 132 can rotate the breadth of one tooth of the wheel 133. In the normal position thepawl 132 engages in the wheel 133, and, in consequence of the action of the driving spring 'of the carriage, is so rotated that the plate 144 lies against the stop 145. The driving spring of the carriage acts against a spring l147 1which is attached on the one hand to the pin 148 on the plate 130, and on the other hand to the stop 149 on the plate 144. As soon as the wheel 133 is displaced axially, the pawl 131 in the first place engages in the wheel 133. The pawl 131 then leaves the wheel 133, and the disk130 now rotates under the action of the driving spring ot the carriage until the plate 144 lies against the stop 145. I

The bush or sleeve 134 has at its lower end an extension 89 with an annular groove 90. In this groove there slide two pins 91 and 92 which do not prevent the bush r0- tating but are ablel to displace it axially. These pins are mounted on a fork-shaped arm 93 which. can rotate around the axle 49. On the two ends of the latter there are two arms 50 and 5 1 which carry vertically pendent rods 63 at their front'ends. The arms 50 and 51 are also connected at their trout ends by a rod 52, forming with the axle 49, a feeding frame. At the bottom end of the rod 63 there is a universal bar 65 situated below the key-lever 10. When pressed by a corresponding key, this universal bar is moved downward by a stop or nose'67 attached to the key-lever. This downward motion is transmitted to the rod 63, lever 93, and bush 89 with the toothed wheels 133 and 135.

The awl mechanism of the wheel 135 (Fig. 55) is operated as follows: The pawl 137 has a. shoulder 94 which is engaged by @vases a connecting 'rod 95. The latter is attached to the bottom end of a lever 96 which 'rotates with a universal bar 66 by thevertical rodsl 64-and are also connected at .their front ends by a rod 62 forminga feeding frame. Then vthe universal bar 66 is moved downward (Fig. 4) the-axle 59 is rotated so that the lever 96 moves the'pawls 137. and 138 by means of the connecting rod 95.

For obtaining a larger numberot extents of shift-ingthe paper-carriage, more than two shifting mechanisms may beconnected one wlth another. This maybe done in many ways. For example, instead of the disk 130 being attached to the axle 27, this disk may.

be arranged on a bush revoluble loosely around the axle 27,ahd a ratchet Wheel may also be placed on this bush, the wheel being shifted by mechanism such as is represented in Fi 6. Instead of this ratchetwheel, the disk which is then o posite the ratchet wheel can lbe madevdisplaceable axially in suitable manner. Another -device for'shiftin the paper-carriage a large number of. 1 d1 erent extents' is had when the arrangement according to Figs. 1 to 4 is combined with that according to Figs. 5 to 7. In this manner an arrangement is obtained likethat shown in Fig. 7 'In this case four or more on which bevel wheels 33 and 3K1 rotate. 0n

ratchet wheelsjcan be employed collectively. Here agaln 26 1s the pinion which'engages in the rack of the paper carriage.. 2 7 -is the axle of this mechanism which carries a` ring 30. On the latter are two pivots 31 and 32 the axle 27 there' rotate, further, two bevel wheels 35 and 36 which however are not firmly connected with it.l At each of the vlatter Wheels there are two pawls, namel at the wheel 35 the pawls 160 and 161, an .at

the laxle 27. When a suitable key 'the wheel 36 the `pawls 162-V and 163. The

pawls 161 and 163 are not pivoted directly on the wheels 35 and 36, but on arms 164 and 165 which can rotate a small amount with regard to thewheels 35 and 36. The pawls 160 and 161 engagealternately in a ratchet wheel 166.A Thelatter is attached on a sleeve or bush 167 which rotates loosely on the axle 27 and carries a second ratchet wheel 168. In the normal position the pawl 161 engages in the wheel 166 and prevents the bevel The pawl 160 then engages inl the Wheel 166 andthe pawly 161 Vis disengaged. from the s ame Wheel. lThese pawls act in like manner the is de- 'as the device just described andrepresented in Fig. 4. On account of the pawls 160 and 161 engagingalternately, the wheel 35 is released so that it can rotate the width o f one tooth of the Wheel 166'. The wheel 35 is axle 27, bevel wheels 33'and 34, and the wheel The bevel wheels 33 and 34C thenv rollon the bevel wheel 36 which is tobe considered stationary at present. They therefore cause the pivots 31 and 32 and-with them the axle 27 to rotate half the amount which the wheel 35 has rotated. Onthe ratchet wheel 168 there is anordinary pawl mechanism, not shown in the figure, with pawls which engage alternately in the wheel 168, somewhat like that represented in Fig. 5. When this pawl and ratchet mechanism is operated the 'wheel is shifted forward the breadth of one .the Wheels 166 and 1.68 are displaced longirotated by the action of the driving spring" of the carriage which acts onthe pinion 26,

tudinally, the pawls remain in unchanged engagement with the r wheel( Vh'en the wheel 168 rotates it of course alsof rotatesthe wheell 166 firmly connected with-it and llkewise the vWheel A35. The latter is rotated in consequence of the motion'transmitted by pawl 161 whichis in the teeth of the Wheel166. Half the amount of this rotation is also transmitted to the axle 27 It the pawl mechanism, acting .on the wheel 168 1s operated, and if the wheels 168 and 166 are simultaneously displiced longitudinally,

both the wheel 168 is shifted on onetooth forward and also the awl 161 in the wheel 166. namely in its re ative positlon to the Wheel 166. The bevel wheel 35 is rotated ananiount which is equal to the sum of the two rotations which the Wheel 168 'makes relatively to its pawl mechanism and to the .\vl1eel'166. Half the sum of these rotations is transmitted'to the axle 27, so that in this case the rotation of the axle is equal to halfy the sum of the two individual amounts of rotation. y

At thewheel 36 there isa devi-ce corresponding to that last described consisting-o? the pawls 162 and 163, the ratchet w 170, sleeve 'or bush 171 and ratchet wheel 172. The ratchet wheels 170 and172- are displaceable with the bush 171 in the ,longi tudinal direction of the axle 27, and, Whendisplaced, rotate the wheel 36 relatively to the wheel 170. Further the wheel 172 is shifted by a special pawl'mechanism. Here also there are two possibilities ofshifting which can be used each by itself and alsov both simultaneously.

The. sleeves or bushes 167 and 171 with their corresponding wheels are shifted axially'by the 'ends 174v and 175 of these bushes Awhich are provided with annular` grooves. In these grooves there engage, 1n known manner, pms which are moved by the keys by means of suitable lever transmission gearing. The extents which the Wheels 166, 16S, 17() and 172 are shifted are perfectly independent of one another, so that four different possibilities of shifting are had by operating each ratchet Wheel. rlhese four possibilities can be further combined in optional manner if several ratchet Wheels operate simultaneously. Fifteen different extents of shifting are obtained in all, of which eleven can be obtained as the sum of two or more of the four independent movements.

Besides being employed for typewriters, the herein described invention may also be used for making perforated bands which are to be used for type setting or for automatic telegraphy. In apparatus for making perforated bands for type setting nia- Ychincs there must be connected With the perforating apparatus a device which adds together the breadth of the different letters within one line and indicates the totalat any moment to the composer. This is a socalled type space indicator. In this manner either a typewriter of suitable construction, such as that described in my American Letters Patent No.- 851,504 of April 23,

1907, may be used with the perforating. apparatus, -Which typewriter is then to be rovided with a shifting apparatus accor ing to the present invention, or there may be connected With the perforating apparatus a special letter-counter `which allows the total. breadth of letters in one line to be read -on a rectilinear or circular scale.

What I claim as my invention and desire to secure by Letters Patent isi:

l. In a variable-feed mechanism, the combination With a frame, a plurality of key-levers, carrying stops, pivoted on the frame, and an axle, carrying a pinion, journaled in the frame, of a differential gear,

`carrying two ratchet Wheels, on said axle,

two feeding frames mounted to rock on the former frame, paWl mechanism on said feeding frames for. actuating said ratchet Wheels. universal bars suspended from said feeding frames and transversely of said key-lever normally under one group of said stops, and levers, substantially as shown, for shifting said bar under the other group of said stops. y

2. In a variable-feed mechanism, the combination With an axle to be rotated in steps of dierent extent, of a central differential gear adapted to drive said axle, two differential gears, each provided with two ratchet wheels, mounted loose on said axle, one at each side of, and adapted to drive, said central differential gear` and pawl mechanismsl for actuating each of said ratchet wheels, substantially as shown.

In a typewriter, the combination with a. frame, and an axle journaled in the frame. of adislt, carrying paWls, attached to said axle, a sleeve having an annular groove loose on said axle, a ratchet wheel on said sleeve adapted to be engaged by said pawls. a second ratchet Wheel on saidsleeve, pawl mechanism engaging the llatter ratchet Wheel, tWo feeding frames mounted to rock on the former frame, an arm on one feeding frame slidable in the groove of said sleeve, a rod, carrying said paw] mechanism, attached to the other feeding frame, a keylever having two noses pivoted in said frame, two universal bars arranged under said i noses transversely of said key-lever, and rods connecting one bar with one feeding frame and the other bar with the other feeding frame.

In testimony whereof I have signed my name' to this specication in the presence of two subscribing witnesses.

Y HEINRICH DREWELL.

Witnesses WOLDEMAB HAUPT, HENRY HASPER.

Images