US2118963A - Ribbon feed mechanism - Google Patents

Description

May 31, 1938. B.- BERIA 2,118,963

RIBBON FEED MECHANISM Filed April 7, 1957' s Sheets-Sheet 1 Fig. 1

y 1,193s. B. BERIA 2,118,963

RIBBON FEED MECHANISM Filed April 7, 1937 3 Sheets-Sheet 2 35 fi N 24 25 May 31,1938. B. BERIA 2,118,963

RIBBON FEED MECHANISM Fild April 7-, 1937 s Sheets-Sheet a Patented May 31, 1938 I UNITED STATES RIBBON FEED MECHANISM Biagio Beria, Turin, Italy Application April '7, 1937, Serial No. 135,576 In Italy April 10, 1936 7 Claims.

This invention relates to a mechanism by means of which the inking ribbon of printing devices is advanced by a step-by-step movement and the direction of feed is reversed before the ribbon is all unwound from a spool.

It is an object of this invention to insure a reliable advance and reversal of the ribbon by making the engagement of the driving pawl with the ratchet wheel positive.

A further object of this invention is to maintain said reliability in working for a long time without the necessity of overhauls or replacement of parts, by eliminating striking of the driving pawl on the ratchet wheel during the return stroke of the pawl. These features render the mechanism according to this invention more particularly suitable for use in connection with cash registers and other registering machines.

Further objects of the invention will appear from the detailed description of the drawings in which a preferred form of the object of the invention is illustrated. In this preferred form each of the two spools for the inking ribbon is solidly connected with a ratchet wheel and the two pawls for actuating said wheels are articulated to a support which is oscillated reciprocately by the printing mechanism. An abutment which is displaced by the inking ribbonas unwinding is near completion, is struck by one of the two pawls at the end of the idle or return stroke whereby the pawl is brought into engagement. At the end of the forward stroke the pawls strike against a further abutment which brings them out of engagement.

Figure 1 is a front view of the ribbon feed mechanism;

Figure 2 is a section on the line II-II of Fig. 1.

Figure 3 is in its left half a section on the line III-III, in its right half a section on the line III---III of Figure 2.

Figure 4 is a partial section on the line IV-'-IV of Figure 2.

Figure 5 is a more diagrammatical view showing the mechanism driving means and the path of the ribbon on a smaller scale.

The base plate I has fixedly attached thereto a vertical wall 2 formed with a central opening 2 and side flanges 3, 3 (Figures 2 and 3). A pivot 4, 4' is mounted on each of the flanges 3, 3 and is fixedly connected with one of the spools 5, 5 for the inking ribbon 6. The ribbon 6 travels from the spool 5 over the spool I as far as the edge 9, inclined through 45, of the plate I, on which it is deflected at right angles. Thence the ribbon travels over an inclined edge on the other side of the plate I, is bent at right angles again and passing over the roller 'I' reaches the spool 5'. In the printing zone which is situated between the inclined edges 9, the'plate I is formed with a recess I0 (Fig. 3). Two levers I2 and I2 are pivoted by means of the pivots 8 and 8' on the front wall 2 and their ends control the inking ribbon 6 which is fitted with two eyelets, hooks or the like I3, said eyelets being a small distance apart from the respective ribbon ends. Shortly before unwinding of the ribbon from one spool is completed, the eyelet I3 at this end abuts the lever I2 or I2, respectively, and oscillates it against the action of the spring II or II, respectively.

A slidable plate I4 is guided by means of two slits I5, I5 on the pivots I6, I6 screwed in the upper portion of the wall 2. The plate I4 is formed above with a flange I1 and below with two cams I8, I8 entering the opening 2 in the wall 2. The plate I4 is either in the position displaced towards the right, as shown in Figure 1, or in the position displaced towards the left, according as to whether the inking ribbon is being wound on the spool 5, in which case the plate is in its right-hand position or on the spool 5 in which case the plate is in its left-hand position. The plate displacement produces in the manner hereinafter described the reversal of the ribbon-feed and is obtained by means of the following mechanism. The plate I 4 is provided with a central abutment I9 which is situated in the path of two arms 20, 20' pivoted after the manner of scissors on the bush 2| mounted in the lower portion of the wall 2. The arms are provided with teeth 20*, 20* and extensions 20 and 20" between which the actuating spring 43 is stretched. The arms 20, 20 are normally situated in the position shown in Figure 1 for the arm 20', in which the tooth 20 bears against the action of spring 43 on the step 42 formed on the above mentioned lever I2. As shown also by Figure 1, as the eyelet I3 of the inking ribbon strikes against the lever I2, the latter is rocked clockwise and the step 42 on the lever I2 is released from the tooth 20, so that the lever 20 under the action of spring 43 performs an oscillation towards the right displacing the plate I4 by means of the abutment I9. The displacement towards the left is performed as the other eyelet I3 strikes against the lever I2, thereby releasing the tooth 20" and rocking the arm 20' towards the left. As shall be hereinafter described, after each reversal, the arm 20 or 20' having moved the plate is returned to its normal position, in which its tooth 20 or 20" bears on the respective step 42, by the member 44 which moves downwardly pushing apart the inner sides of the flanges 20 and 20 on the arms 20, 20' against the tension of spring 43, till the step 42 under the action of spring II or II is returned underneath its respective tooth 20 or 20*.

The ribbon feed mechanism is driven by the cam 45 (Fig. 5) performing on each printing operation a turn which is transformed into a reciprocating oscillation of the lever 46 pivoted at 41 and under the action of the return spring 48. An arm on the lever 46 acts by means of a pin and slot guide on the lever 49 keyed on the shaft 23, having further keyed thereto the arm 24; consequently, the latter is oscillated reciprocally on each operation. The arm 24 acts by means of a pin (25) and slot guide on the beam 26 keyed on the pivot 21 extending between the above mentioned pivots 4 and 4' for the spools 5, 5'. The pivot 21 is arranged in the support 22 having its upper portion U-shaped and secured by means of the screw 22 to the wall 2, and carries two arms 28, 28'.

The beam 26 and two arms 28, 28 therefore perform on each printing operation a forward oscillation indicated in Fig. 2 by the arrow A and a return oscillation indicated by the arrow B. A pawl 29, 29' is articulated to each arm 28, 28' by means of a pivot 32, 32', respectively. A ratchet wheel 3| is actuated by the pawl 29 and a ratchet wheel 3| is actuated by the pawl 29', the former wheel being fixedly connected with the pivot 4 for the spool 5, while the latter is fixedly connected with the pivot 4 for the spool 5 for the inking ribbon 6.

According as to whether the pawl 29 or 29 is in engagement with the wheel 3| or 3| during oscillation in the direction A, the spool 5 or spool 5' is positively operated and the inking ribbon winds up thereon. This engagement of either pawl 29 or 29' is produced by the flange IT on the plate l4, whilst at the end of each forward or operative oscillation of the arms 28, 28', both pawls 29, 29' are positively disengaged by their extensions 35, striking against a cross bar 38 mounted on the flanges 3 and 3. At the end of the return oscillation of the arms (idle stroke in the direction B) the extensions 35, 35' enter slots with inclined bottom 2 opening into the opening 2 in the wall 2, and according to the position of the plate l4 the extension 35 on the pawl 29 or the extension 35' on the pawl 29' strikes the flanges I! on the plate, whereby the respective pawLengages the ratchet wheel 3|, 3|, respectively. Supposing the last displacement of the plate H has been produced by the eyelet l3 provided on the ribbon 6 near the spool 5 by striking against the lever l2, the flange II has come into the path of the extension 35 on the pawl 29 and at the end of each return oscillation (direction B) the pawl 29 is engaged so that on the next forward oscillation the spool 5 is driven and the ribbon 6 is unwound from the reel 5'. In the position shown in Fig. 1 the eyelet |3 coming from the spool 5' strikes against the lever |2. The flange I1 is removed from the path of the extension 35 and enters the path of the extension 35' on the pawl 29'. The ratchet wheel 3| and spool 5' are thereupon positively rotated whilst the pawl 29 is left all the time disengaged from its ratchet wheel 3|. A small cylinder 44 is arranged on the rear end of the beam 26 and oscillates on each operation in the space between the two arms 20, 2|! returning after displacement of the plate H the respective arm 20 or 20 to its normal position.

To keep the pawls 29, 29 in a determined position with respect to the arms 28, 28' till they strike against the cross bar 38 or flange H, the end of each pawl is provided with a leaf spring 4| acting on a ball arranged in a hole in the pawl (Fig. 4). Depending upon the engaged or disengaged position of the respective pawl, the ball 40 enters one or the other of two recesses 39 in the oscillating arms 28, 28', keeping the pawl in the desired position with respect to the arm 23 or 28, till it is disengaged by striking against the rod 38 or engaged by the striking against the flange Opposite each ratchet wheel 3|, 3| a stop pawl 30 is articulated by means of the pin 33 to the fixed support 22 and is drawn to its engaged position by the spring 31. To release the spool 5 or 5' from which the inking ribbon 6 unwinds, the stop pawl acting on the ratchet wheel 3|, 3| of said spool should remain disengaged. This is effected in accordance with the displacements of the plate I 4 by the cams I8 and I8. Said cams act upon the extension 34 on the stop pawls 30.

In the position shown in Figures 1 and 2, in which the pawl 29, 35 is inoperative, the extension 34 on the stop pawl 30 is pushed by the cam l8, so that the pawl remains out of engagement of the respective stop wheel 3|. As soon as the plate I4 is arranged to actuate the pawl 29, 35, the stop pawl 30 of the respective ratchet wheel 3| is released and is left in engagement with said wheel 3| by virtue of the tension of the spring 31.

While I have shown but one embodiment of my invention, it is obvious that it may be embodied in other forms covered and defined by the appended claims.

What I claim is:

1. A ribbon feed mechanism having two spools for the ends of the ribbon, comprising for each spool, in combination, a ratchet wheel coupled for rotation with the spool, a pawl for driving said ratchet wheel, a support for said driving pawl, means for imparting a reciprocatory movement to said support, a stop for said driving pawl to bring it out of engagement from the ratchet wheel at the end of its operative stroke. a second stop for the driving pawl to bring it into engagement with the ratchet wheel at the end of its return stroke, and ribbon controlled means for bringing said second stop into and out of operative position.

2. A mechanism according to claim 1, in which the two spools, ratchet wheels and pawl supports are pivoted side by side about a common axis.

3. A ribbon feed mechanism having two spools for the ends of the ribbon, comprising for each spool, in combination, a ratchet wheel coupled for rotation with the spool. a pawl for driving said ratchet wheel, a support for said driving pawl, means for imparting a reciprocatory movement to said support, a stop for said driving pawl to bring it out of engagement from the ratchet wheel at the end of its operative stroke, a second stop for the driving pawl to bring it into engagement with the ratchet wheel at the end of its return stroke, a spring latch between said driving pawl and its support for retaining the driving pawl in its engaged and disengaged position, and ribbon controlled means for bringing said second stop into and cut of its operative position.

4. A ribbon feed mechanism having two spools for the ends of the ribbon, a slide and ribbon controlled means for displacing said slide, comprising for each spool, in combination, a ratchet wheel coupled for rotation with the spool, a pawl for driving said ratchet wheel, a support for said driving pawl, means for imparting a reciprocatory movement to said support, a stop for said driving pawl to bring it out of engagement from the ratchet wheel at the end of its operative stroke, a second stop for the driving pawl to bring it into engagement with the ratchet wheel at the end of its return stroke, said second stop being mounted on said slide in such manner as to come into and out of its operative position by the efiect of the displacements of the slide, a stop pawl for said ratchet wheel, a spring for bringing said stop pawl into engagement with the ratchet wheel, and a cam on said slide for bringing said stop pawl out oi. engagement from the ratchet wheel.

5. A ribbon feed mechanism having two spools for the ends of the ribbon, a slide and ribbon controlled means for displacing said slide, comprising for each spool, in combination, a ratchet wheel coupled for rotation with the spool, a pawl for driving said ratchet wheel, a support for said driving pawl, means for imparting a reciprocatory movement to said support, a stop for said driving pawl to bring it out of engagement from the ratchet wheel at the end of its operative stroke, a second stop for the driving pawl to bring it into engagement with the ratchet wheel at the end of its return stroke, said second stop being mounted on said slide in such manner as to come into and out of its operative position by the eifect of the displacements of the slide, a spring latch between said driving pawl and its support for retaining the driving pawl in engaged and disengaged position, a stop pawl for .said ratchet wheel, a spring for bringing said stop pawl into engagement with the ratchet wheel, and a cam on said slide for bringing said stop pawl out of engagement from the ratchet wheel.

6. A ribbon feed mechanism having two spools for the ends of the ribbon and a displaceable slide, comprising for each spool, in combination, a ratchet wheel coupled for rotation with the spool, a pawl for driving said ratchet wheel, a support for said driving pawl, means for imparting a reciprocatory movement to said support, a stop for said driving pawl to bring it out of engagement from the ratchet wheel at the end of its operative stroke, a second stop for the driving pawl to bring it into engagement with the ratchet wheel at the end of its return stroke, said second stop being mounted on said slide in such manner as to come into and out of operative position by the eilect of the displacements of the slide, a spring actuated lever for displacing said slide, a ribbon controlled latch for retaining said lever in inoperative position, and a restoring member for said lever coupledwith said pawl supports.

7. A ribbon feed mechanism having two spools for the ends of the ribbon and a displaceable slide, comprising for each spool, in combination, a ratchet wheel coupled for rotation with the spool, a pawl for driving said ratchet wheel, a support for said driving pawl, means for imparting a reciprocatory movement to said support, a stop for said driving pawl to bring it out of engagement from the ratchet wheel at the end of its operative stroke, a second stop for the driving pawl to bring it into engagement with the ratchet wheel at the end of its return stroke, said second stop being mounted on said slide in such manner as to come into and out of operative position by the eflfect of the displacements of the slide, a spring latch between said driving pawl and its support for retaining the driving pawl in engaged and disengaged position, a stop pawl for said ratchet wheel, a spring for bringing said stop pawl into engagement with the ratchet wheel, a cam on said slide for bringing said stop pawl out of engagement from the ratchet wheel, a springactuated lever for displacing said slide, a ribbon controlled latch for retaining said lever in inoperative position, and a restoring member for said lever coupled with said pawl supports.

BIAGIO BERIA.

Images