US2331970A - Ribbon attachment for typewriting machines - Google Patents

Description

Oct. 19, 1943. J. R. GESER 2,331,970

RIBBON ATTACHMENT FOR TYPEWRITING MACHINES Filed April 17, 1941 {a El Wdmmm *M Patented Oct. 19, 1943 2,331,970 RIBBON ATTACHMENT FOR TYPEWRITING MACHINES Josefineltosa Geser, Zurich, Switzerland Application April 17, 1941, Serial No. 389,084 In Switzerland October 9, 1940 6 Claims. (Cl. 197153) This invention relates to a ribbon attachment for typewriting machines and serving to make carbon copies without the use of carbon paper. More particularly it relates to the mechanism for reversing the direction of ribbon travel, as in approaching the end of the ribbon carried by a spool from which the ribbon is being unwound.

Devices of the above type are known. In my Patent No. 2,281,688, dated May 5, 1942, for example, there is disclosed a device of this type in which periodic ribbon reversal is provided for in the form of a power storage device. This device includes a lead screw which is actuated during use of the machine to tension a spring. When ribbon reversal is required the spring isreleased to reverse the direction of ribbon travel and to condition another power storage device at the other end of the platen for the next reversal at the proper time. The ribbon carrying means is associated with the platen so that it can be swung into or out of writing position. When in writing position, the ribbon is driven by friction rollers which engage the platen.

The present invention relates to mechanism of the above type and is designed to improve and simplify the power storage device which actuates the ribbon reversing mechanism. It is arranged to cause the power storage device to be conditioned by forward rotation of the platen through a friction drive and interposed gearing independently of any manual means. A spiral spring is used in the power storage device and it carries a blade which engages the threads of a leadscrew. The particular improvement of the pres! ent invention is that ribbon actuating means driven by the platen includes a one-way clutch whichdrives the ribbon when the platen is turned forwardly, but interrupts the drive when the platen i turned backwardly.

An embodiment of the invention is illustrated in the drawing in which,

Figure 1 is a plan view of a typewriting machine with apparatus of the present invention mounted thereon.

Figure 2 is an nd view looking in the direction of the arrow A in Figure 1, with the front cover plate removed.

Figure 3 is a detail sectional view of a portion oi the ribbon reversing means of the present invention, the section being on line I1I-III of Figure 2.

Figure 4 is a detail view of a one-way clutch forming a part of the ribbon controlling means, the clutch being shown in the position it occupies when the platen is being turned backwardly.

Figure 5 is an enlarged sectional view of the clutch.

The component parts of thearrangement will be described as applied solely to one side of the apparatus inasmuch as the other side may be re-' garded as a symmetrical mirror image thereof starting from a central plane.

In the drawing, l designates the platen, the I ends of which carry the knobs la and lb, Reference characters 2a and 2b designate the ribbons of the apparatus, e, g., two, which are superposed and which are supplied from and wound up on common spools 3a and 3b. Numeral 8 indicates driven by the friction roller I 5, which is also toothed or milled, through gears I, I, and I2.

The ribbon 2b passes over a tensioning roller 23 and around the reversing roller 25 to the reversing plate 28, and the ribbon 2a. passes through the dog 26 to the reversing plate29. The dog 26 is pulled down in the direction of the arrow B by the carrier 21 attachedto the ribbon 2a.

A steel band I3 is attached to the dog 26 the other end of said band being pivotally connected by means of bolt M with the cross lever l6.' The stud I'I rigidly mounted in housing 6 extends through one end of the'cross lever l6 and the upper end of the striker member 18. The latter has a stationary pivot stud l9 through agency of which, when the steel band I3 is pulled in the direction of arrow B, the follower blade 20 which is disposed on the striker member I 8 is caused to be lifted out of the threads of the lead-screw or worm 2| at which instant the striker member I8 is urged rapidly to the right under the action of spring 22 (see Figure 3), thus causing the nose 24 of the striker member to displace the clutch operating member 30, gears l and I2, and the clutch halves la and |2a carried by collars 1 and I2 respectively on said gear to the right on shaft 31. This displacement causes the gears I and 4 to, mesh and at the same time displaces the shift rod 32 to the right, whereas on the opposite side of theapparatu the reverse procedure takes place, that is, the ribbon spool drive mechanism is disengaged from the friction roller by disengaging the gears 1 and 4.

The power storing spring 22 is interposed between the left side of follower blade 20 and the front housing cover So. When the lead-screw 2! is rotated, the blade 20 travels to the left (Figure 3), thus serving to tension the power storing spring 22.

A leaf spring 34 which bears against a nose [6a of the cross lever 16 serves, through stud I9, to force the follower blade 20 back into the threads of the lead screw 2! after it has been withdrawn therefrom,

As shown in Figure 3, when the platen I is turned in a forward direction, the rotary motion transmitted therefrom through the friction roller I5 is transmitted to gear i2, and through the clutch to the gear 1 and thence to the gear 4 associated with the lead-screw 2|. n the other hand, if the platen l is turned backwards, that is, in the direction of arrow C, the friction roller 15 and the gear I2 will be rotated along with it, but the gear 1 will be disengaged through agency of the clutch as the parts 1a, Ila thereof separate. A spring 33 serves to tend to urge the two clutch halves la and l2a together. In general, the inherent friction of the drive mechanism suffices to release the clutch when the platen is turned backwards. However, braking springs or the like may be used to bear against the side face of gear 5 so as to produce the frictional resistance necessary for overcoming the tension of spring 33.

Figure 4 shows the claw clutch when the platen is being turned backwards and at the instant when the obliquely surfaced jaws of the clutch separate as they slide over each other.

I claim:

1. A copy ribbon attachment for typewriting machines comprising a frame adapted for mounting in operative association with a typewriter platen, a ribbon carrying spool at each end of the frame, friction driving means adapted to engage the platen to drive said spools, power storage means for reversing the direction of ribbon movement under predetermined conditions, means including a gear train actuated by rotation of the platen in the forward direction for causing said power storage device to store up power, a oneway clutch in said gear train to disconnect the platen from the power storage device when the platen is turned rearwardly, and means for releasing the power storage device to drive the ribbon when the ribbon has reached a predetermined position for reversal.

2. A copy ribbon attachment for typewriting machines comprising a frame adapted for mounting in operative association with a typewriter platen, a ribbon carrying spool at each end of the frame, friction driving means adapted to engage the platen to drive said spools, means associated with each ribbon spool for reversing the direction of ribbon movement comprising a power storing spring, a lead-screw, means including a gear train actuated by rotation of the platen in the forward direction to actuate said lead-screw and tension said spring, a one-way clutch in said gear train to disconnect the platen from the power storage device when the platen is turned rearwardly, and means for releasing the power storage device to drive the ribbon when the ribbon has reached a predetermined position for reversal.

3. A ribbon attachment for typewriters comprising a frame carrying two ribbon spools, one at each end thereof, means for mounting said frame in operative relation to a typewriter platen to bring the ribbon in juxtaposition to the platen, a power storage device at each end of said frame and comprising a lead-screw, a spring arranged to be tensioned by rotation of said lead-screw, platen driven means including a gear train for actuating said lead-screw, a one-way clutch in said gear train to disconnect the platen from the power storage device when the platen is turned rearwardly, and means for releasing the power storage device to drive the ribbon when the ribbon has reached a predetermined position for reversal.

4. A ribbon attachment for typewriters comprising a frame carrying two ribbon spools, one at each end thereof, means for mounting said frame in operative relation to a typewriter platen to bring the ribbon in juxtaposition to the platen, a power storage device at each end of said frame and comprising a lead-screw, a spring arranged to be tensioned by rotation of said lead-screw, and means actuated by said lead-screw for tensioning said spring, friction driving means including a gear train effective during forward rotation only of said platen for actuating said lead-screw, a one-way clutch in said gear train to disconnect the platen from the power storage device when the platen is turned rearwardly, and means for releasing the power storage device to drive the ribbon when the ribbon has reached a predetermined position for reversal.

5. A ribbon attachment for typewriters comprising a frame carrying two ribbon spools, one at each end thereof, means for pivotally mounting said frame on a typewriter carriage with the ribbon carried by said spools operatively associated with the typewriter platen, friction drive means connected to the platen for advancing said ribbon past the writing station, and means for reversing the direction of ribbon movement comprising an actuating spring, a lead-screw, a blade engaging said lead-screw, means driven by the platen and including a gear train for tensioning said spring, a one-way clutch in said gear train to disconnect the platen from the power storage device when the platen is turned rearwardly, and means for releasing the power storage device to drive the ribbon when the ribbon has reached a predetermined position for reversal.

6. A ribbon attachment for typewriters comprising a frame carrying two ribbon spools, one at each end thereof, means for pivotally mounting said frame on a typewriter carriage with the ribbon carried by said spools operatively associated with the typewriter platen, friction drive means connected to the platen for advancing said ribbon past the writing station, a power storage device for reversing said ribbon, said device comprising a lead-screw driven from said friction drive means, a power storing spring, and a blade engaging the threads on said lead-screw and serving to tension said spring, a clutch for drivingly disconnecting said tensioning means from the friction drive means when the platen is rotated in a backward direction, and means for releasing the power storage device to drive the ribbon when the ribbon has reached a predetermined position for reversal.

J OSEFINE ROSA GESER.

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