Title:
RIBBON FORK ACTUATING AND LOCKING DEVICE
United States Patent 3648818


Abstract:
The carrier lever of the ribbon fork is mounted on a control shaft to which a control lever is secured. The carrier lever and control lever have slots through which a rod operated by the universal bar of the typewriter passes. The shape of the slots is selected so that in accordance with the set angular position of the control shaft, the ribbon fork is raised from an inoperative position to at least one operative position, and then locked when the rod passes through parallel slot portions.



Inventors:
SCHEINPFLUG GUNTER
Application Number:
04/864070
Publication Date:
03/14/1972
Filing Date:
10/06/1969
Assignee:
TRIUMPH WERKE NURNBERG AG.
Primary Class:
Other Classes:
400/216.1
International Classes:
B41J35/10; B41J35/14; (IPC1-7): B41J33/56
Field of Search:
197/157,158,159
View Patent Images:
US Patent References:
3233716Ribbon positioning arrangement1966-02-08Grashoff
1072899N/A1913-09-09Barr
0936044N/A1909-10-05



Primary Examiner:
Wright Jr., Ernest T.
Claims:
I claim

1. In combination with a typewriter including a universal bar, a ribbon fork actuating and locking device comprising a ribbon fork; carrier means connected with said ribbon fork for movement with said ribbon fork between an inoperative position and at least one operative position, said carrier means being formed with a first guideway; control means formed with a second guideway having a drive portion transverse to said first guideway, and a locking portion parallel with said first guideway; connecting slide means connected with said universal bar and operated by said universal bar between a normal position and an actuated position; and setting means for setting said control means between a locking position in which said connecting slide means in said normal position is located in said parallel locking portion and first guideway so that said carrier means and ribbon fork are locked in said inoperative position and remain locked in said inoperative position during movement of said connecting slide means to said actuated position, and at least one driving position in which said connecting slide means in said normal position is located in said transverse drive portion and in said first guideway so that said carrier means and said ribbon fork are moved to said operative position during movement of said connecting slide means in said transverse drive portion and in said first guideway toward said actuated position until said connecting slide means enters said locking portion while continuing movement in said first guideway whereby said carrier means and said ribbon fork are locked in said operative position.

2. A device as claimed in claim 1 comprising means supporting said carrier means and said control means for relative movement about a common axis; wherein said drive portion of said second guideway is circular and has a center located in said axis; and wherein said locking portion of said second guideway and said first guideway are straight.

3. A device as claimed in claim 1 wherein said control means include a control shaft supported for angular movement about an axis and a control lever secured to said control shaft and being formed with said second guideway; wherein said drive portion of said second guideway is circular and has a center located in said axis; and wherein said carrier means include a carrier lever mounted on said control shaft for angular movement about said axis and having said first guideway; wherein said first and second guideways are slots, and wherein said locking portion of said second guideway and said first guideway are straight slots.

4. A device as claimed in claim 3 wherein said connecting slide means include a straight rod fitting into said slots and being parallel with said axis, a link pivotally connected with said rod, and lever means pivotally connected with said link and with said universal bar.

5. A device as claimed in claim 4 including spring means connecting said rod with said control lever and biassing said connecting slide means toward said normal position.

6. A device as claimed in claim 3 wherein said setting means include a manually operable setting member secured to said control shaft for angular movement and having at least first and second arresting recesses, and resilient catch means cooperating with said arresting recesses in different angular positions of said control shaft for arresting said control shaft with said control lever in said locking and driving positions of said control means.

7. A device as claimed in claim 1 comprising supporting means; wherein said control means includes a control shaft mounted on said supporting means for angular movement, and a control member having said second guideway and being secured to said control shaft; wherein said carrier means includes a carrier member having said first guideway and mounted on said control shaft for angular movement about the axis of said control shaft so that said control member and said carrier member move in first and second parallel planes.

8. A device as claimed in claim 7 wherein said drive portion of said second guideway is part-circular and has a center located in said axis.

9. A device as claimed in claim 7 wherein said carrier member is an angular carrier lever having one arm formed with said first guideway and another arm supporting said ribbon fork; wherein said control member is an angular control lever having one arm formed with said second guideway and being substantially parallel with said one arm of said angular carrier lever, and an other arm secured to said control shaft; wherein said first and second guideways are slots; and wherein said connecting slide means include a rod parallel to said axis and located in said slots slidably mounted in said slots, and a spring connecting said rod with said other arm of said angular control lever.

10. A device as claimed in claim 7 wherein said connecting slide means include a straight rod located in a third plane perpendicular to said first and second planes and parallel to said axis of said control shaft, said rod passing through said first and second guideways so that said locking portion of said second guideway and said first guideway are located in said third plane when said control means is in said locking position and said carrier means is in said inoperative position; and wherein said second guideway is displaced relative to said rod in said normal position, and to said carrier means and first guideway when said setting means is set to said driving position; and wherein said locking portion is again located in said third plane when said rod enters said locking portion after passing through said drive portion of said second guideway.

Description:
BACKGROUND OF THE INVENTION

The ribbon fork of a typewriter is operated from the universal bar between operative positions in which red or black portions of an ink ribbon are located in the path of the type lever, and a position in which the ribbon is not engaged by the types, so that a stencil can be made.

It is necessary to start the displacement of the ribbon fork shortly after the start of the movement of a type bar, so that still sufficient time is available for terminating oscillations of the ribbon fork and parts connected with the same. In order to produce clear and accurate imprints without smears, the ink ribbon must have arrived before engagement by a type in the respective position, and be completely free of oscillations or vibrations. Particularly, when ink ribbons having different zones for red and blue are used, it is necessary that the ribbon is exactly and at the right time positioned for being engaged by the types, so that imprints combining two different colors are reliably prevented.

In accordance with the prior art, as represented by the German Pat. No. 1,153,776, the ribbon fork is locked before the type bar arrives in the printing position, and is maintained until the imprint has been made. In the prior art construction, it is necessary for each color zone to provide a stop part which has to be individually adjusted. Particularly in electric typewriters, there is only space laterally of the type actions left for the adjusting means so that long linkages are required which result in friction losses and a complicated structure. Furthermore, the construction has to be adapted to an electric typewriter to such a degree, that it cannot be used for a manual typewriter.

SUMMARY OF THE INVENTION

It is one object of the invention to overcome the disadvantages of known ribbon fork actuating and locking devices, and to actuate and lock the ribbon fork by a simple, compact, efficient, and inexpensive device consisting of few parts.

Another object of the invention is to provide a ribbon fork actuating and locking device which can be placed closely to the universal bar of the typewriter by which the device is controlled.

Another object of the invention is to move the ribbon fork to an operative position while the type bar moves over a small part of its path, while during the remaining part of the movement of the type bar, the ribbon fork is locked in the operative position.

It is another object of the invention to provide a ribbon fork actuating device which can be used in an electric typewriter and in a manual typewriter.

With these objects in view, an embodiment of the invention comprises a control lever fixed to a shaft, and a carrier lever for the ribbon fork turnably mounted on the shaft, the control lever and the carrier lever having different guideways through which a spring-biassed rod passes. In order to set the device for different displacements of the ribbon fork, corresponding to different color zones of a ribbon, it is only necessary to adjust the angular position of the shaft, which can be accomplished by manually operated arresting means.

Broadly speaking, a ribbon fork adjusting and locking device according to the invention comprises a carrier means connected with the ribbon fork for movement with the same between an inoperative position and at least one operative position, the carrier means being formed with the first guideway; control means formed with the second guideway having a drive portion transverse to the first guideway and a locking portion parallel with the first guideway; connecting slide means connected with the universal bar of a typewriter and operated by the same between a normal position and an actuated position; and setting means for setting the control means between a locking position in which the connecting slide means in the normal position is located in the parallel locking portion and first guideway, and at least one driving position in which the connecting slide means in the normal position is located in the transverse drive portion and in the first guideway.

When the control means is in the locking position, the carrier means and ribbon fork are locked in the inoperative position and remain locked during movement of the connecting slide means to the actuated position moving in the locking portion and first guideway.

In the driving position the carrier means and the ribbon fork are moved to the operative position during movement of the connecting slide means in the transverse drive portion and in the first guideway toward the actuated position. When the connecting slide means enters the locking portion while continuing movement in the first guideway, the carrier means and the ribbon fork are locked in the newly obtained operative position.

Preferably, the carrier means and control means are supported for relative movement about a common axis, and the drive portion of the second guideway is circular and has a center located in the axis, while tbe locking portion of the second guideway and the first guideway are straight.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a fragmentary perspective and exploded view illustrating an apparatus according to the invention;

FIG. 2 is a fragmentary side elevation illustrating the apparatus in an inoperative position;

FIG. 3 is a fragmentary side elevation illustrating the apparatus in a first operative position in which the upper color zone of the ink ribbon is used; and

FIG. 4 is a fragmentary side elevation illustrating the apparatus in another operative position in which the lower color zone is used.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In a partly shown side wall 1 of the typewriter housing, and in a stationary frame bracket 2, a control shaft 3 is mounted for angular movement, and carries a fixed setting arm 4 provided at its lower end with arresting recesses 6, 7 and 8 cooperating with a resilient catch in the form of a leaf spring 10 which is secured by a screw 46 to a flange 47 of side wall 1 and has a catch portion 11 which engages one of the arresting recesses 8, 7 and 6, as shown in FIGS. 2, 3 and 4, and finally a stop portion 5. Setting arm 4 is turned in counterclockwise direction beyond the position shown in FIG. 4 under the control of manual means including a manually operated member 44 connected by a wire link 43 with setting arm 4. The manually operated member 44 has a finger engaging portion 44a indicating the positions of the setting means 4 to 11, and is mounted in the region of the keyboard of the typewriter on a fixed pivot pin 45. As best seen in FIG. 1, setting arm 4 is a thin plate whose stop portion 5 passes through a slot 9 in leaf spring 10 so that catch portion 11 of spring 10 symmetrically engages the respective arresting recess 6, 7 or 8. By operation of manually operated member 44, control shaft 3 is turned between three angular positions in which it is held due to the engagement of one of the arresting recesses 6, 7 and 8 by leaf spring 10, 11.

An angular control lever 12 is fixed to control shaft 3, and turns with the same when the angular position of control shaft 3 is set. The lower arm 12a of control lever 12 has a guideway in the form of an angular slot consisting of a drive portion 14 and a locking portion 13. Locking portion 13 is straight, and drive portion 14 extends transverse to locking portion 13 and is part-circular with its center located in the axis of control shaft 3.

Adjacent control lever 12, an angular carrier lever 18 is mounted on control shaft 3 for free rotation relative to the same. Carrier lever 18 has an upper arm 21 having a bearing bore 22 in which a pivot pin 23 is mounted for connecting the end of arm 21 with the ribbon fork 24 through which an ink ribbon can be threaded in the usual manner. The lower arm 19 of carrier lever 18 also has a guideway in the form of a straight slot 20 whose length and width correspond to the length and width of the straight locking portion 13 of guideway 14, 13 in control lever 12.

A connecting slide in the form of a cylindrical rod 25 has a diameter corresponding to the width of the guideways 13, 14 and 20, and passes through the same. When slide rod 25 is located in slot portions 13 and 20, as shown in FIG. 1, carrier lever 18 cannot move relative to the control means 3, 12 which are locked by the setting means 4 to 11. Slide rod 25 is connected with one end of a spring 17 whose other end is hooked into a hole 16 in a transverse lug 15 on control lever 12. A ring 26 prevents axial sliding of the end of spring 17 on slide rod 25. Spring 17 urges slide rod 25 to move toward control shaft 3 to the ends of slot 20 and of locking slot portion 13 as shown in FIG. 1, and movement of slide rod 25 into the transverse drive slot portion 14 is not possible since this would require turning of control lever 12 which is locked with control shaft 3 by the setting means 4 to 11. Consequently, carrier means 18 to 23, and ribbon fork 24 are locked in the normal inoperative position of rest shown in FIG. 1.

The end of slide rod 25 is connected to a link 27 which has a stud 28 located in a slot 29 having a wider assembly portion 30 and being formed in a double armed connecting lever 31 which is mounted on a shaft 32 supported in lateral wall 1, and in another lateral wall, not shown, of the typewriter frame. All drive levers 33 of all type actions are mounted on shaft 32. The upper free end of connecting lever 31 is connected with the universal bar 34 of the typewriter. The drive levers 33, of which only one is shown, are closely spaced mounted on shaft 32 and have projecting portions 35. When a key lever, not shown, is operated, a coupling pawl 36, biassed by a spring 38, is released by a trigger lever 37 for movement to a position in which the tooth 36a is engaged by a tooth 39a of a continuously rotating snatch roll 39. The spring 38 connects coupling pawl 36 with trigger lever 37 so that a nose 36b of coupling pawl 36 normally abuts the same. In the position of rest, drive lever 33 abuts a stop bar 40 under the action of a spring 41. Drive lever 33 is connected in the usual manner by a wire 42 to an intermediate lever and a type bar of a type action, not shown.

OPERATION

In the inoperative position of the apparatus shown in FIGS. 1 and 2, setting arm 4 has been set to a position in which arresting recess 8 is engaged by the arresting spring 10, 11. In this locking position the ribbon fork 24 is locked, and does not move when a type action is actuated.

As shown in FIGS. 1 and 2, the straight locking slot portion 13 and the straight slot portion 20 are located in a common plane in which also slide rod 25 is located. The plane is perpendicular to the planes in which the control lever 12 and carrier lever 18 move about the axis of shaft 3. This locking position of the setting means 4 to 11 is obtained by angularly displacing the manually operated member 44 in the region of the keyboard.

When a key lever, not shown, is operated, trigger lever 37 releases coupling pawl 36 whose tooth 36a is engaged by a tooth 39a of the power snatch roll 39 so that drive lever 33 turns about shaft 32 and displaces universal bar 34 by its projecting nose 35 in the direction of the arrow B. Connecting lever 31 is thus turned in counterclockwise direction about shaft 32 and moves link 27 in the direction of the arrow A.

Connecting rod 25 moves out of the position shown in FIGS. 1 and 2 and in slot 20 and locking slot portion 13 toward the free ends of lever arms 19 and 12a. Since slide rod 25 is located in the same plane as slot 20 and locking slot portion 13, carrier lever 18 is not displaced so that the ink ribbon fork 24 remains in the same position, and in fact is locked in the inoperative position shown in FIGS. 1 and 2 since control means 3, 12 cannot turn due to the setting means 4 to 11. During the movement of the slide rod 25 in the direction of the arrow A, spring 17 is tensioned so that slide rod 25 and link 27 with stud 28 are moved by spring 17 in a direction opposite to the arrow A during the return movement of the respective actuated type action while stud 28 moves in slot 29. Due to the provision of slot 29 in connecting lever 31, spring 17 displaces slide rod 25 and link 27 with stud 28 without displacing connecting lever 31. The universal bar 34, which has to perform other functions in addition to the movement of the ribbon fork 24, is biassed by an other spring, not shown.

By operation of the manually operated means 44, the setting means 4 to 11 can be set to the operative positions shown in FIGS. 3 and 4 in which the ribbon fork 24 places the upper and lower color zones of an ink ribbon, not shown, in an operative position in which the respective zone is engaged by the type, not shown, of an actuated type action. As shown in FIG. 3, the upper arm 21 of carrier lever 18 has to be raised a distance x for placing the upper zone of the ink ribbon, not shown, in the operative position, and as shown in FIG. 4, the arm 21 has to be raised a distance y from the inoperative position shown in FIGS. 1 and 2 in order to place the lower color zone of the ink ribbon, not shown, in the operative position.

To obtain the use of the upper color zone of the ink ribbon, not shown, setting arm 4 is turned with control shaft 3 until arresting recess 7 is engaged by the catch portion 11 of spring 10 so that control means 3, 12 are locked in a certain angular position. During turning of the control means 3, 12 with setting member 4 in counterclockwise direction from the position of FIG. 2 to the position of FIG. 3, drive slot portion 14 turns to a position in which slide rod 25 is located in the middle of the part-circular drive slot portion 14. The movement of drive slot portion 14 relative to slide rod 25 has not caused a displacement of the same since the center of the part-circular drive slot portion 14 coincides with the axis of control shaft 3. However, when a key lever is now actuated, and a type action operated, universal bar 34 performs a movement which is transmitted by connecting lever 31 to link 27 which moves slide rod 25 in the direction of the arrow A from the middle of the curved drive slot portion 14 toward the beginning of the straight locking slot portion 13. Due to the camming action of the transverse drive slot portion 14, slide rod 25 is raised and displaces arm 19 and thereby the entire carrier lever 18 so that the ribbon fork 24 is raised the distance x. When slot 20 is again located in the same plane as the locking slot portion 13, slide rod 25 continues its movement in the direction of the arrow A without displacing the carrier lever 18 and the ribbon fork 24. Irrespective of the fact that slide rod 25 continues its movement with the universal bar 34, ribbon fork 24 remains locked since the presence of slide rod 25 in the locking slot portion 13 and in slot 20 prevents any movement of the carrier lever 18 relative to the control lever 12.

If the use of the upper color zone of the ink ribbon, not shown, is desired, manually operated means 44 is shifted to a position in which arresting spring 10, 11 engages arresting recess 6, as shown in FIG. 4. Since slide rod 25 does not move, it is located at the left end of the part-circular drive slot portion 14 at the end of the adjustment of the setting means 4 to 11, but remains at the left end of slot 20.

When a type action is now operated and the universal bar 34 is moved in the direction of the arrow B in FIG. 1, connecting lever 31 moves link 27 and thereby slide rod 25 in the direction of the arrow A. While slide rod 25 moves in the left part of slot 20, it moves along the curved drive slot portion 14 from the left end to the right end of the same in a direction transverse to the direction of slot 20 in arm 19 of carrier lever 18, so that carrier lever 18 is turned on the arrested control shaft 3 in counterclockwise direction for raising the ribbon fork 24 the distance y so that the lower color zone of the ink ribbon, not shown, is located in the path of movement of the type of the actuated type action.

Slide rod 25 is now located at the beginning of the straight locking slot portion 13, and intermediate the ends of the slot 20, and the straight slot 20 is again located in the same plane as the straight slot portion 13 and slide rod 25. Consequently, further movement of slide rod 25 to the right as viewed in the drawing in the straight locking slot portion 13 and in the straight slot 20 cannot cause any angular displacement of the carrier means 18 to 23 with the ribbon fork 24, and the ribbon fork 24 is locked due to the fact that carrier arm 19 is prevented from moving relative to control shaft 3 by slide rod 25 and the fixedly locked arm 12a of control lever 12.

By suitably designing the ratio of the lengths of the part-circular drive slot portion 14 and of the straight locking slot portion 13, the time during which the carrier means 18 to 23 with the ribbon fork 24 are moved during the movement of the type action, can be exactly determined so that only a small part of the time during which the type bar performs its printing stroke, is used for the setting of the ribbon fork 24.

From the above description of a preferred embodiment it will become apparent that the present invention provides a ribbon fork actuating and locking device consisting of few and simple parts which transmit force from the universal bar 34 to the ribbon fork 24 along a very short path. Due to this simple and compact construction, no particular changes of the mechanism are required for using the same either in a manual typewriter, or in an electric typewriter.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of ribbon fork actuating devices differing from the types described above.

While the invention has been illustrated and described as embodied in a ribbon fork actuating and locking device including a slotted carrier lever and a slotted control lever connected by a slide rod, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.