US2463259A - Device for positioning a sheet and for indicating the approach of the sheet end on a typewriter - Google Patents

Description

March I, 1949. R GIAUQUE 2,463,259

DEVICE FOR POSITIONING A SHEET AND FOR I NDICATING THE APPROACH OF THE SHEET END ON TYPEWRITERS Filed Feb. 21, 1946 Patented Mar. 1, 1949 UNITED STATES DEVICE FOR POSITIONING A SHEET AND FOR INDICATING THE APPROACH OF THE SHEET END {)N A TYPEWRITER Rene Giauque, Yverdon, Switzerland, assignor to Paillard S. A. (Paillard A. G., Paillard Limited), a corporation of Switzerland Application February 21, 1946, Serial No. 649,278 In Switzerland February 22, 1945 13 Claims. 1

My invention relates to devices for feeding a sheet of paper to the platen of a typewriter, and for indicating to the operator the approach of the end of the sheet. It has been found useful in typewriters to provide a device permitting the introduction and rapid positioning on the platen of the sheet at the proper height of the first writing line. It has also been found desirable to provide a device capable of indicating the approach of the bottom end of the sheet by means of visible or audible signals. These devices allow for a substantial increase in the speed of typewriting work.

Designs known heretofore comprise in general two distinct and independent devices, one for the positioning of the sheet, the other one for signalling the approach of the end of the sheet. Besides, these devices have been adapted especially for being fitted to existing typewriters, a fact which necessarily leads to cumbersome designs which are not convenient and do not properly fulfil their function because the new requirements imposed by the devices frequently do not conform to the normal features of the existing typewriter. For instance, there exist devices resulting in a shortening of the effective length of the platen, others do not permit of manipulating freely the platen by means of both of its control knobs, others necessitate an additional handling when positioning a new sheet and this even when the sheet end signalling device is not utilised.

Lastly, experience has shown that it is absolutely necessary for the platen to remain always free for rotational movements so as to not handicap the typist in his work.

Certain designers have proposed to connect mechanically and positively the sheet positioning device witha sheet end signalling device. To this effect, devices such as the one described in Prezioso Patent No. 2,365,903 are provided with a large gear wheel driven through pawls by a crank controlling the introduction of the sheet. This large wheel actuates, on one'hand, members controlling the sheet end signaling devices and on the other hand a device indicating the various starting positions of the platen corresponding to the length of the sheet utilised. These devices are not entirely satisfactory, because they are costly to manufacture and because their use compels. the twist to place the platen in a predetermined starting, position before introducing each new sheet in the typewriter, this starting position depending obviously upon the length of the sheet. It may be readily realized, that even when a position indicating means is provided, this positionmg of the platen represents a loss of time particularly when the sheet is of random size.

An object of the present invention is to provide an improved device or mechanism for positioning the sheet and for signalling the approach of the bottom end of the sheet being typewritten,

this device being especially constructed for obviating the aforesaid disadvantages While acting at the same time as an indicator of the starting position of the sheet inserted between the platen and its adjacent rolls and as. an indicator of the approach of the bottom end of the sheet being typewritten, predeterminedly adjustable abutment means being provided to take care of the desired upper margin, and mechanical setting means automatically'setting the sheet end indicator in predetermined angular relationship with respect to the platen shaft on the typewriter, this device comprising further a master'gear driven in rotation by a crank which controls the introduction of the sheets and drives the mechanism through a coupling means effective in one direction only, the sheet end indicator being driven by a clutch means allowing a relative displacement between its driving and driven member to be set and maintained.

Another object of the present invention is to provide a device of this class wherein the sheet end indicator is in the form of a rotatably displaceable member, which may be advantageously a sector, a barrel or a drum freely rotatable on the platen shaft and bearing numbered graduations cooperating with reference register marks on the edge of a window in the housing, said register mark indicating the various sheet sizes to be used, and a simple reading of the numerals'appe'aring on the graduation in register with the register mark" for the sheet size in use giving the number of lines still available on the sheet being typewritten.

Another object of the present invention is to provide a device of this class, wherein the mechanical setting means for automatically setting the sheet end indicator is formed by a retaining member positively driven in rotation by the crank at its own rate of rotation and by projecting members integral with the drum, said retaining and projecting members cooperating in such a way as to prevent the drum from being driven until it has reached a predetermined angular position with respect to the platen of the typewriter.

Another object of the present invention is to provide a device of this class, wherein a mechanical clutch rotary motion transmitting means between the platen shaft and the sheet end indicator allows for a definite angular displacement of said indicator to be set and maintained in one direction only with respect to the platen shaft while preventing an angular displacement of the platen under the influence of inertia forces, a preferred form of said clutch rotary motion transmitting means consisting in a helical spring mounted with light friction only on cylindrical surfaces or hubs provided on both the driving member and the driven member of the clutch means.

Another object of the present invention is to provide a device of this class, wherein an oscillating lever is pivoted on a member driven by the crank and designed for contacting the adjustable abutment means and which lever oscillates in such a manner as to look a driving pawl in mesh with the teeth of the master gear, and designed further to act as a stop for the whole mechanism against the adjustable abutment means.

Another object of the present invention is to provide a device of this class, wherein the predeterminedly adjustable abutment means is formed by a retaining pawl and a fixed toothed segment, the shape of the teeth of the latter being substantially symmetrical in order to allow for the relative displacement of this pawl in either direction with respect to the segment, a crank actuated member acting in turn on the pawl to lock it with the gear teeth with a force increasing with the force applied to the crank.

A further object of the present invention is to provide a device of this class, wherein means are provided for preventing any rotation of the platen under the influence of inertia forces when the crank is being operated and suddenly stopped, particularly when the crank becomes stopped by the engagement of the crank actuated revolving stop against the adjustable abutment means.

Still a further object of the present invention is to provide a device of this class, wherein means are provided for automatically urging the driving pawl into mesh with the teeth of the master gear from the very start of the operation of the crank, an intermediate member loosely rotatable on the crank shaft being driven in rotation by an oscillating lever provided on a revolving member fixed to said crank shaft, the intermediate member being provided with a circular sector frictionally retained by the shoes of a brake mounted on the housing, the intermediate member acting on the driving pawl to lock it into mesh with the teeth of the master gear.

With these and such other objects in view as will incidentally appear hereinafter, the invention comprises the novel construction, combination and arrangement of parts that will now be described in detail with reference to the accompanying diagrammatic drawing exemplifying the same in a. non-limitative manner and forming a part of the present disclosure.

The sole figure of the accompanying drawing shows diagrammatically and by way of example a form of embodiment of the sheet positioning and sheet end signalling device which is the object of the present invention.

The figure is a perspective exploded View of the device whose elements placed in difierent planes are separated for the sake of clearness, assuming certain parts to be broken away and others removed.

In the form of the invention represented, the platen 2 of the typewriter is controlled by a platen shaft I, revolving in bearings provided in the lateral walls of a housing 3, a portion only of which is represented on the drawing, this housing protecting the members of the mechanism against dust and accidental mishandling.

For introducing and positioning the sheet, the device has a handle lever arm or crank 4, fixed to a feed control spindle rotating freely in bear- .ings (not represented), provided in the lateral walls of the housing 3. On this spindle 5 is mounted freely a large toothed wheel or master all) gear 6 meshing with a pinion I fastened to the platen shaft I. The spindle 5 bears, rigidly fastened to it, a driving member 8 on which is pivoted on bolt 26 a pawl 9 cooperating with the teeth I2 of the master gear 5 for driving the latter. This pawl 9 is urged into mesh with the teeth I2 of the master gear 6 by a tension spring 50. One end of this spring I0 is fastened at IIla to an ear 28 of an intermediate plate member 2I. As may be seen. this pawl 9 constitutes with the teeth of the master gear 6 a coupling means effective in one direction only. The spindle 5 and driving member 8 are subjected to the action of a restoring spring II tending to bring the crank 4 to its position of rest, which position is defined by a stop 43 fastened to a support 3a mounted on the housing 3.

A graduated drum I4, freely rotatably mounted on the shaft I, is driven in rotation through a coupling permitting of a relative angular displacement between its two members to beobtained in particular when one of them is subjected to the action of a braking moment while the other is being driven. This coupling is constituted by a helical spring I5, both ends of which are mounted with light friction only on a hub I6 of the drum I4, and on a hub I? of the pinion I respectively.

The drum I4 has further various projecting fingers I8 extending parallel to platen shaft I and evenly distributed on a circle concentric with platen shaft I. These fingers are adapted to cooperate with a sector l9 fastened to the driving member 8. The length of the chord of the sector i9 is less than the distance between two consecutive fingers I8. The drum I4 has, evenly distributed on its periphery, as many graduated circumferential numbered sequence scales as there are fingers I8.

The spindle 5 carries also freely mounted thereon, an intermediate plate member 2 I. This plate member has a sector 22 engaged between the shoes 24 of a brake. One of the shoes of the latter is fastened to the frame or housing through a stem, the other shoe slidable on this stem is subjected to the action of a spring 23 which causes the sector 22 to become pinched between the shoes 24.

This intermediate plate member 2| has further a slot opening 25 giving passage to the pivot bolt 26 on which is pivoted the pawl 9. In the position of rest of the crank 4 against stop 43, the disengagement of the pawl 9 from the teeth I2 is caused by the face 21 of the pawl coming into contact with the ear 28 of the intermediate member 2|. In a similar manner, when the crank 4 is actuated by being pulled forward, the engagement of the pawl 9 with the teeth I2 of master gear 6 is urged on the one hand by the spring I0 and on the other hand for safetys sake, secured by another ear 29 of the intermediate member 2|, this ear coming into contact with the face 30 of the pawl 9.

Lastly, the spindle 5 carries further freely rotatably mounted a two arm lever 3I, one arm of which has a setting button 32 projecting from the housing 3 through a window 33 thereon, one edge of which bears a graduated scale indicating the length of the desired upper margin. On the other arm of this lever 3i is pivoted a, pawl 34 urged by a spring 35 into mesh with the teeth of a fixed toothed sector 36 fixedly carried on stationary part 3a fastened to housing 3. This pawl 34 has a nose 3'! adapted to come into contact, during the later portion of the forward strokeof the'crank 4, with an ear 38 of an arm 39' pivoted on the driving member 8; at the same time, a heel 40 of the arm 33 displaces the intermediate plate member 2| by pushing against an ear 4|.

The operation of the device is as follows:

Before putting a sheet on the platen, the desired height of the upper margin is set by means of the setting button 32, and by setting its pointer on the proper division of the graduated scale adjacent Window 22. The shape of the teeth 36 and the shape of the pawl 34 allow for the displacement of the lever 3! equally well in both directions, but once the control button 32- is set in a given position, the adjustable abutment formed by the nose 3'! is securely held in position by the action of the pawl teeth urged into mesh by the spring 35 with the teeth of segment 36.

After the desired height of the upper margin has been thus set, the lever or crank 4 is manually pulled forward in a counterclockwise direction as seen from the right hand side of the figure against the action of its restoring spring II. The crank 4 then drives the spindle 5 and the driving member 8 carrying the pawl 9. The pivot 26 of the latter moves forward a slight distance within the slot opening 25 of the interme diate plate member 2! so that the front face 30 of the pawl comes in engagement with the ear 29 of intermediate member 2!. The ear 29 sliding over the face 3!], acts on the pawl 9 to reenforce the action of the spring 10 and compels the pawl 9 to remain in mesh with the teeth I 2 of the master gear 6. From this moment on by application of bolt 23 to the front edge of slot 25, the pawl 9 drives the master gear 6 and the intermediate plate member 21, easily overcoming the retarding friction of the brake 24. The braking action of the latter applies a force to bolt 26 which maintains the pawl 9 in mesh with the teeth l2.

While the above described movements have taken place, a slight angular displacement has been produced between the intermediate plate member 2i and the driving member 8 sufficient. to lock the pawl 9 in its engaged position with respect to the teeth !2, the arcuate slot opening 25 leaving the necessary clearance around bolt or stud 23 for this.

Very nearly at the end of the manual forward feed stroke of the crank 4, that is to say just before the sheet comes to the first writing line chosen thereon and set by the position of the control button 32, the front face of ear 38 of the pivoted arm 39 comes into contact with the nose 3'! of the pawl 34. This arm 33 then rocks, on its pivot in a clockwise direction and pushes againstv the intermediate plate member 21 by means of the heel 49 of arm 39 coming into contact with the ear 4! of plate member 2|. The rocking of the lever 39 causes the intermediate plate member 2! to perform an angular displacement greater than that of the driving member 8 around the spindle 5 and plate member 2! is therefore moved forward with respect to the latter While overcoming the slight braking action of the shoes 24, which action causes the releasing of pawl 9, as the edge 53 of the ear 29 of plate member 2| passes beyond the face 39: of pawl 9. But, the front face of ear 38 of lever 39 still contacting the nose 3'! of pawl 34, the continued forward manual operation of the crank 4 causes the forward face 38 of the pawl 9 to come into contact with the back side of the ear 38 of arm '39, said car 33 extending substantially below the The pinion i drives positively the drum i4.

' when the drum 1-! becomes released from lower edge 50 of the ear 29 of intermediate plate member 2 l In this manner, the pawl 9 becomes now locked in a very positive manner, its teeth meshing with the teeth I2 of the master gear 6. The forward face 30 of the pawl 9 bears on the rear face of car 38, which itself bears on the nose 3.1 and en'- forces the locking of the pawl 34 in the teeth of fixed sector 35. It will be noted that the stronger is the force applied to the crank 4, the more effective is this locking action of the pawls 9 and 34, so that the extent of travel of the crank 4 becomes exactly defined and secured with all the certainty desired by the pawl 34 engaged with the teeth 36. It follows that the angular movement of the platen 2. is also perfectly defined by the cooperation of the ear 38 of arm 39 functioning as a pivoted stop with the adjustable abutment means consisting of the nose 3? of the pawl 34. Furthermore, an angular displacement of the platen 2 under the influence of its inertia forces is entirely prevented, the pawl 9 being locked either by the edge 59 of Bar 29 or the car 38 of lever 39 which cannot go further forward, thus preventing all angular displacements of the master gear 6.

When the master gear 3- is rotated forward as above described, it drives, by means of pinion l; the platen shaft 5 and the platen cylinder 2. rotates the graduated drum 44 through the friction coupling consisting of hub 5], spring l5 andhub l6.

Depending on the starting position of this drum, a corresponding one of the fingers l3 car.- ried on drum I4 is engaged by the sector I 9. In this case, the drum i4 being braked, the fric tion coupling l5, l3, H slips up to the moment where this sector l9 escapes from the finger It. From this moment on, the coupling it, It, ll Thus, during the positioning of a sheet, the sector l9 always permits an escapement release of the finger 53 for one and the same angular position of the drum it with respect to the upper edge of this sheet, it being assumed that, when the sheet is introduced, its upper edge always comes substantially into the same position with respect to the inlet opening formed by the platen and therearwardly located sheet gripping rolls (not shown). Thus, sector l9, it is positioned always in one and the same angular position exactly defined with respect to the upper edge of the sheet introduced on the platen on one hand, and on the other hand with respect to the set of reference register marks R provided on a stationary part 342 fastened to the housing 3.

These register marks are designed to be read against the graduations on the drum l4. They correspond-to the various lengths of the different standard sheet sizes and are located in defined angular positions such for instance, that they exactly register with the Zero division of the-scale on the drum 94 when the lower edge of the sheet of the length corresponding to a given register mark reaches the level of the writing line of the types on the platen.

When, after the sheet has been brought auto-- matically to the level of the first writing line by pulling crank 4 as far forward as the setting of nose 3? will permit, the crank 4 is released from the finger of the operator, the return spring Hv urges the crank 4 in a clockwise direction. During this movement, the return spring ll causesreturn backward movement. also of the member 8 and the pawl 9. effects then with respect to the intermediate plate member 2|, and its slot 25 an angular movement which brings back face 21 of the pawl 9 into contact with the ear 28 of intermediate plate member 2|. Under the retaining action of the brake shoes 24 on intermediate plate member 2I, the car 28 lifts the claws of the pawl 9 which become disengaged from the teeth I2 of the master gear 6. From this moment on, the intermediate plate member 2i is pulled back clockwise and it follows the clockwise return backward movement of the crank 4, overcoming the slight braking action of the shoes 24.

During this entire backward movement, the pawl 9 is maintained out of engagement with the teeth 52 of master gear 8, by the ear 28 of intermediate plate member ZI which is in contact with the back face 21 of the pawl 9 whereby an objectionable ratchet noise is avoided.

As indicated above, the position of rest of the crank 4, when released, is defined by the stop 43 fastened on housing 3.

From the preceding, it may be noted that it is only necessary for the typist to set the size of the desired upper margin or caption space by means of the setting button 32, and then to pull forward the crank 4. Regardless of the length of the sheet used, no adjustment of the sheet bottom end approach indicator I4 is necessary, the latter becoming set automatically by the sector I9 in an angular position defined with respect to the upper edge of the sheet engaged on the platen.

While using the typewriter, it will be sufncient for the typist to glance at the register mark corresponding to the length of the sheet being typewritten and read the graduation of dial I4 in register with this register mark to know the number of lines still available before reaching the bottom end of the sheet. It is evident that during the typing of a whole sheet, various zero lines corresponding each to one of the graduated scales of the drum I4 will pass the register mark of index R corresponding to the length of the sheet being used.

This feature is not objectionable though, because of the considerable distance separating two graduations bearing the same numerals on different scales on drum I4. It is practically impossible to mistake one of these graduations for the other owing to the fact that for all of them, except the one to be used, the bottom edge of the sheet being typewritten is still visible projecting well out of the platen behind the latter and clearly indicates that the bottom margin is still far from the writing line of the type on the platen.

From the drawing it may be noted, that the reliability of operation of the device is quite satisfactory; in fact, the pawls 9 and 34 are secured in their engaged position by a mechanism urging them into mesh with the respective teeth with a force increasing with the force applied to the crank 4. This particular feature enables the pawl 9 to cooperate satisfactorily with the teeth I2 of master gear ii, in spite of the fact that these teeth have a symmetrical shape adapted for meshing with the pinion I. In fact, if the above described locking mechanism was not present, the pawl 9 might jump over the gear teeth I2. The same applies to the pawl 34 which must allow for the manual displacement of the setting button 32 in a clockwise direction and in the opposite direction as well. Further, the coupling spring The latter I I5 effects a grip on bearing surfaces I6 and I1 sufficient to drive the sheet end indicator I4 without slipping with respect to the platen shaft I, when the platen 2 is manually operated by means of either of its control knobs (not shown).

Lastly, when the crank 4 is being operated, if it is released before the end of the forward stroke, that is to say before the end of the initial part of the cycles of movements performed by the master gear and the platen, as defined by the position of the settting button 32, the platen 2 will tend to continue its movement of rotation under the influence of is inertia forces. But such a movement of the platen 2 is made entirely impossible either by the action of the edge 50 of the ear 29 of intermediate member 2| or by the action of the ear 38 of lever 39 locking the pawl 9 in mesh with the teeth l2, this action affording then a rigid connection between the platen 2 and the crank 4.

In a similar manner, when at the end of its forward stroke, the crank 4 is stopped by the action of the locked pawl 34 and of the ear 38 of lever 39 against the abutment forming nose 31 of pawl 34, the drum I4 is subjected to inertia forces and tends to continue its motion of rotation. It is prevented from doing so by the feature of the coupling spring I5. This spring is wound in a direction such that, with the drum I4 revolving in a clockwise direction under the action of the crank 4, if the pinion I is suddenly brought to a standstill, the inertia forces in the drum I4 owing to the frictional forces existing between hubs I6 and IT and coupling spring I5, tend to close on themselves the turns of this spring bearing on these surfaces. The resulting increased frictional forces make it impossible for the spring to slip on either of the hubs I6 and 11. Thus, the drum I4, under the action of the inertia forces due to its own mass, may cause a slight elastic deformation of the coupling spring I5, but it will come back to its correct relative position when the inertia forces have ceased and there will be no remanent angular displacement of the drum I4 with respect to the pinion I. This requirement obviously implies an appropriate stiffness of the coupling spring I5 with respect to the magnitude of inertia forces of the drum I4 and the grip of the coupling spring I5 on its bearing surfaces I6 and II.

On the other hand, when the drum I4, revolving in a clockwise direction under the action of the crank 4, is stopped by the sector I9 acting on fingers I8, the frictional forces exerted by bearing surfaces I6 and I! on the coupling spring I5 have the tendency of opening the windings of this spring. The decreased frictional forces so produced permit of an easy sliding of the spring I5 on its bearing surfaces, whereby a well determined angular displacement is produced between the drum I4 and the pinion I.

It will be apparent that I have provided a novel and very useful device for feeding paper to a typewriter platen, and for indicating the approach of the end of the sheet. To those skilled in the art, it will be apparent that my invention is susceptible of various modifications, and all such modifications which are comprehended with the scope of the appended claims, I consider to be within the spirit of my invention.

I claim:

1. In sheet control means for a typewriter, a combination of a housing, a platen and a platen shaft mounted for rotatable sheet feeding movement, a control member, a first window in said housing for said control member, a pinion fixed on said platen shaft, a master gear meshing with said pinion, a manually operated crank with a crank shaft for initially moving said platen through a part of its cycle, mechanical coupling means between said crank and said master gear effective for rotationally-driving said master gear and said platen in one direction only, predeterminedly adjustable abutment means settable by said control member, a crank actuated revolving stop, said stop cooperating with said abutment means for limiting said part of said cycle of said platen and the stroke of said crank, a sheet end indicator for indicating the approach of the bot tom end of the sheet being typewritten, a second window in said housing for said sheet end ind"- cator, an impositive mechanical clutch means between said platen shaft and said sheet end indicator for driving said indicator, said clutch means permitting a definite angular displacement of said indicator to be set and maintained with respect to said platen shaft, and mechanical setting means driven by said crank shaft for automatically setting said sheet end indicator in predetermined angular relationship with respect to said platen shaft during the earlier portion of said part of said cycle of said platen.

2. In a typewriter, a combination as claimed in claim 1, in which said sheet end indicator is formed by a drum loosely mounted on said platen shaft.

3. In a typewriter, a combination as claimed in claim 1, in which said sheet end indicator is formed by a drum loosely mounted on said platen shaft, said drum having on its periphery numbered graduations cooperating with reference indexes on the edge of said second window in said housing, said indexes connoting the various sheet sizes to be used, the mere reading of the numerals on the graduation facing the index connoting the sheet size in use. giving the number of lines still available on the sheet being typewritten.

4. In a typewriter, a combination as claimed in claim 1, in which said sheet end indicator comprises a drum loosely mounted on the platen shaft and in which the mechanical setting means for automatically setting said sheet end indicator is formed by a retaining member positively driven in rotation by said crank at the angular velocity of said crank and by projecting members integral with said drum, said retaining member following a path crossing that of said projecting members on said drum, said retaining member cooperating with one of said projecting members for preventing said drum from being driven in synchronism with said platen shaft until said drum has reached a predetermined angular position with respect to said platen.

5. In a typewriter, a combination as claimed in claim 1, in which said impositive mechanical clutch means between said platen shaft and said sheet end indicator comprises resilient engageable coupling means tightly engaging both said platen shaft and said indicator for one and only one direction of relative rotating displacement thereof and allowing a definite angular displacement of said indicator in one direction only with respect to said platen shaft to be set and maintained, while preventing any angular displacement of said platen under the influence of the inertia forces generated in said platen.

6. In a typewriter, a combination as claimed in claim 1, in which said impositive mechanical clutch means between said platen shaft and said sheet end indicator allows a definite angular displacement of said indicator in one direction only with respect to said platen shaft to be set and maintained, said clutch means preventing any angular displacement of said platen under the influence of the inertia forces generated in said platen, said clutch means being formed by a cylindrical driving member, a cylindrical driven member and a helical spring, both ends of said helical spring being mounted with light friction only on said driven and said driving member respectively, said driving member being fastened to said platen shaft and said driven member being fastened to said drum.

7. In a typewriter, a combination as claimed in claim 1, in which means on said revolving stop and reinforcing the :action of said coupling means between said-crank-and said master gear are provided for preventing any angular displacement of said platen under the influence of inertia forces when said manually operated crank is being operated and is suddenly stopped, particularly at the moment where said crank actuated revolving stop cooperating with said adjustable abutment mean-s for limiting said part of said cycle of said platen causes the whole mechanism to stop.

8. In a typewriter, a combination as claimed in claim 1, said mechanical coupling means comprisa revolving member rigidly fastened to said crank shaft, an oscillating lever, a driving pawl and a stud for said pawl, said oscillating lever being articulated on said revolving member, said pawl stud being fastened to said revolving member, one end of said oscillating lever coming into contact with said adjustable abutment means at the end of said stroke of said crank causing said oscillating lever to oscillate and lock said pawl into mesh with the teeth of said master gear, said end of said oscillating lever on said revolving member acting as the said revolving stop cooperating with said adjustable abutment means.

9. In a typewriter, a combination as claimed in claim 1, in which said predeterminedly adjustable abutment means is formed by a retaining pawl and a fixed toothed segment, said pawl cooperating with the teeth of said toothed segment, said teeth having a substantially symmetrical shape in order to allow for the relative displacement of said pawl in either direction with respect to said toothed segment.

10. In a typewriter, a combination as claimed in claim 1, in which said predeterminedly adjustable abutment means is formed by a retaining pawl and a fixed toothed segment, said pawl cooperating with the teeth of said toothed segment, said teeth having a substantially symmetrical shape in order to allow for the relative displacement of said pawl in either direction with respect to said toothed segment, said revolving stop being provided for locking said pawl in mesh with said teeth with a force increasing with the force exerted upon said crank.

11. In a typewriter, a combination as claimed in claim 1, in which said predeterminedly adjustable abutment means is formed by a retaining pawl and a fixed toothed segment, said pawl cooperating with the teeth of said toothed segment, said teeth having a substantially symmetrical shape in order to allow for the relative displacement of said pawl in either direction with respect to said toothed segment, said revolving stop actuated by said crank acting on a portion of said pawl and urging said pawl into mesh with said teeth of said fixed toothed segment with a force increasing with the effort exerted upon said crank.

12. In a typewriter, a combination as claimed in claim 1, said mechanical coupling means comprising a driving pawl for driving said master gear, and means for automatically urging said pawl into mesh with the teeth of said master gear from the very start of the operation of said manually operated crank.

13. In a typewriter, a combination as claimed in claim 1, said mechanical coupling mean-s comprising a driving pawl for driving said master gear, and means for automatically urging said pawl into mesh with the teeth of said master gear from the very start of the operation of said manually operated crank, a revolving member for supporting said pawl being rigidly fastened to said crank shaft, an intermediate member being mounted loosely on said crank shaft, said revolving member being provided with an engaging member for driving said intermediate member and a stationary brake being mounted on said housing, said intermediate member being provided with a circular sector, the shoes of said brake acting in a retaining manner on said sector when said intermediate member is being driven by said revolving member, said intermediate member acting on said driving pawl to lock same into mesh with the teeth of Said master gear.

GIAUQUE, RENE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,053,920 Neidig Feb. 18, 1913 1,113,572 Neidig Oct. 13, 1914 2,365,903 Prezioso Dec. 26, 1944

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