US3071233A

US3071233A - Shifting arrangement, particularly for typewriters

Info

Publication number: US3071233A
Application number: US103554A
Authority: US
Inventors: Chvatlinsky Kurt
Original assignee: Olympia Werke AG
Current assignee: Olympia Werke AG
Priority date: 1960-04-16
Filing date: 1961-04-17
Publication date: 1963-01-01
Anticipated expiration: 1980-01-01

Description

Jan. 1, 1963 K. CHVATLINSKY SHIFTING ARRANGEMENT, PARTICULARLY FOR TYPEWRITERS Filed April 17, 1961 5 Sheets-Sheet 1 INVENTOR parka-Z J. Fri ro- Jan. 1, 1963 K. CHVATLINSKY 3,071,233

SHIFTING ARRANGEMENT, PARTICULARLY FOR TYPEWRITERS Filed April 17, 1961 a Sheets-Sheet 2 Jan. 1, 1963 K. CHVATLINSKY 3,071,233

SHIFTING ARRANGEMENT, PARTICULARLY FOR TYPEWRITERS Filed April 17, 1961 3 Sheets-Sheet 3 United States Patent 3,071,233 SHIFTING ARRANGE-ll" ENT, PARTICULARLY FOR TYPEWRITERS Kurt Qhvatlinsky, Wilhelmshaven, Germany, assignor to ()lympia Werke AG, Wiihelmshaven, Germany Filed Apr. 17, 1961, Ser. No. 103,554 Claims priority, appiicatien Germany Apr. 16, 1%!) 21 Ciairns. (61. 197- 74) The present invention relates to a shifting arrangement, particularly for typewriters and similar machines where either the paper carriage or the type lever carrier, is shifted from a normal lower case position to an upper case position, and back.

The shifting arrangements according to the prior art which serve this purpose, have the disadvantage that the shifted element is rapidly stopped in its end positions, so that the impact creates shocks and undesired bouncing back of the shifted element. These effects have a detrimental eifect on the straightness of the typed lines, and produce considerable noise. Other shifting arrangements of the prior art require a very complicated structure which increases the production cost and renders repairs diflicult.

It is one object of the present invention to overcome the disadvantages of the known shifting arrangements, and to provide a shifting arrangement of simple construction capable of an almost noiseless operation, and reliably holding the shifted element in its end positions.

Another object of the present invention is to provide a shifting arrangement for shifting an element of a typewriter between an upper case position and a lower case position by the force of a rotary-power roll and under control of a shift key without requiring any manual force for shifting the shifted element.

Another object of the present invention is to provide a shifting arrangement in which resilient means effect initial movements to start the operation, while the main part of the movement is carried out under the action of power means.

Another object of the present invention is to control the movement of a shiftable element in such a manner that the movement of the shiftable element is slow before the shiftable element arrives in its ends positions.

Another object of the present invention is to obtain the optimal speed variation of the shiftable element during its movement.

With these objects in view, the present invention relates to a shifting arrangement which is particularly suited for shifting the carriage element or the type lever carrier element of a typewriter between the lowercase position and the upper case position. One embodiment of the invention comprises in addition to the shiftable element, operating means preferably including a cam with an arcuate cam track, movable between two end positions and connected to the shiftable element for shifting the same; biasing means, preferably a spring, connected to the operating means and urging the same toward a dead center position located intermediate the two end positions; a manually operated shift key member having two positions for holding the operating means, and particularly the cam, in the end positions thereof against the action of the biasing means; and power means which cooperate With the operating means.

In each of the end positions of the operating means, the biasing spring means urge the same to move through an intermediate position toward the dead center position when the shift key is manually shifted from one of its positions to the other position thereof. When the operating means arrives in one of the intermediate positions, the power roll engages the operating means and moves the same through its dead center position to the other end 3fl'? 1,233 Patented Jan. 1, 1963 position where it is again blocked by the shift key memher so that the spring cannot turn the operating means back in the opposite direction toward the dead center position. As soon as the shift key is released, the operating means is also released, and moves first under the action of the biasing spring, and then under the action of the power roll through the dead center position to the first end position thereof, where it is again blocked by the shift key member from returning in opposite direction of the action of the biasing spring.

In the preferred embodiment of the invention, the cam is turnable and is connected to a lever on which the biasing spring acts. The lever is connected. to a drive wheel which cooperates with the power roll. The cam has a cam track slot which cooperates with an adjustable cam follower on the shiftable element. It is particularly advantageous to make the cam track slot adjustable by forming the cam of two parts, one of which is adjustable.

In the preferred embodiment of the invention, the cam track has two end portions which are substantially concentric to the turning axis of the cam, and are connected by sinusoidal cam track center portion. Due to this shape of the cam track, the movement of the shifted element is slow near its end positions where it is under the action of the biasing spring, and rapid while it is driven by the power roll. The concentric end positions also hold the shiftable member in the upper and lower case positions, respectively.

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, in which:

FIG. 1 is a fragmentary side view, partially in section, illustrating an embodiment of the shifting arrangement according to the present invention in its normal position in which the type lever carrier is in the lower case position;

FIG. 2 is a fragmentary side view corresponding to FIG. 1, but showing the shifting arrangement in a differ ent position in which the type lever carrier is in the upper case position; and

FIG. 3 is a fragmentary perspective view illustrating the shifting arrangement of the present invention in the normal position of rest on a reduced scale.

Referring now to the drawings, a type lever carrier 2 is mounted on the Walls 14. and la of a typewriter frame for substantially vertical movement between a lower case position shown in FIG. 1 and an upper case position shown in FIG. 2. The type lever carrier 2 includes two lateral arms 2a and 2b, and a central segment-shaped slotted portion 3 in which the type levers 4 are mounted for turning movement between a normal inoperative position shown in solid lines in FIGS. 1, 2 and 3 and a printing position abutting the platen of the paper carriage as shown in dash and dot lines in FIGS. 1 and 2. Holding plates 6, 6a are secured by threaded means 5 and 5a to the lateral arms 2:: and 2b and carry fixed threaded spindles 7 and 7a. Two nut means 8, 8a and 9, ha are respectively mounted on the threaded spindles 'i and 7a, which also carry washers 10, 10a and 11, 11a.

Buffer springs

12, 12a and 13, 13a are mounted on the spindles 7, 7:: between the washers 1t and 11. The lateral walls 1 and 1a of the frame support brackets 14 and 14a which include yoke portions, and pairs of legs 15a, 16a and 15b, 16b which have forked end portions abutting the outer washers it? and 11. When the type :lever carrier 2 is in its normal position shown in FIG. 1, the nuts 8, 3a abut the'inner washers 19, 10a and compress the springs W 12a since the inner washers 1t 1 3a are shiftable on the spindles 7, 7a, while the nuts 8, 8a are adjustably secured to the threaded portions of the spindles 7, 7a. It is evident that in the upper case position of the type lever carrier 2 shown in FIG. 2, the lower buffer springs 13, 13a are compressed in a corresponding manner.

In the region of the center of carrier 2, a forwardly proj'ecting bracket 17 is fixed, on which a member including a U-shaped portion 19 and an arm 19a is turnably mounted so that its position can be adjusted by turning an eccentric screw 18. Arm 190: carries a rotary cam follower roller 20.

A cam 23 is fixed on a shaft 21 which is mounted for turning movement in the side walls 1 and 1a of the frame. Cam 23 has a cam track slot 23a receiving cam follower roller 20.

A double armed-lever 22 is fixed to shaft 21 and turns with the same between two end positions in which the cam follower is respectively located in the two end portions of the cam track 23a. As clearly shown in the drawing, the end portions of the cam track 23a extend transverse to each other and substantially concentric to the turning axis of cam 23 which is defined by shaft '21. However, the end portions of cam track slot 23a are spaced different radial distances from the turning axis of cam 23, and are connected by a center cam track portion of sinusoidal configuration.

It is evident that turning of shaft 21 with cam 23 from the position shown in FIG. 1 to the position shown in FIG. 2, will force cam follower roller 2t to move from a position farther spaced from shaft 21 to a position closer spaced from shaft 21 so that the type lever carrier 2 is pulled down. During the last part of the movement of the carrier, the buffer springs 13, 13a are compressed and dampen the motion. Due to the fact that the arcuate center portion of the cam track 23a has a greater radius of curvature near its end, the movement of the carrier 2 is slower near its end positions. The substantially tangential direction of the end portions of cam track 23a assures that the carrier '22 is not displaced even if there is a slight relative movement between cam follower 2t) and cam 23 while the carrier is in one of its end positions.

The exact shape of the cam track 23a can be adjusted since an adjustable cam plate 25 is adjustably mounted on the main part of cam 23 and secured to the same by an eccentric screw 24-. A guide pin 23' on the main part of cam 23 slides in a slot 25' of cam plate 25 so that cam plate 25 is accurately guided. Cam plate 2 has an open cam track slot 24a which together with the slot in the main part of cam '23, forms the cam track slot 23a. By adjustment of cam plate 24, the radial distance between slot 24a and shaft 21 can be adjusted whereby the distance of the displacement of the carrier 2 can be adjusted. It will be understood that one of the end portions of cam track slot 23a, is actually constituted by the cam slot 24a of the cam plate 24.

A coil spring 26 is secured to a stud 1c on the frame of the machine, and to the arm 22a of lever 22. Arm 22a extends at an obtuse angle to spring 26 in both end positions of cam 23 shown in FIGS. 1 and 2. Conse quently, spring 26 is tensioned in both positions, and will bias lever 22 to turn to a dead center position in which lever arm 22a extends in the direction of spring 26 and along a line connecting shaft 21 with stud 10. A link 27 is articulated to lever arm 22b and connected by a pivot pin 28 to a control member or drive wheel 29 so that the same is also biased to turn out of the position shown in FIGS. 1 and 2 under the action of spring 26. Drive Wheel 29 is mounted for turning movement on a shaft 29a and has two recessed peripheral portions, and intermediate the same two toothed portions which are shaped and positioned to cooperate with the teeth of a rotary power roll 36 which is mounted in the frame of the machine and driven in a conventional manner by an electric motor, not shown.

When the type lever carrier 2 is in one of its end positions, and the cam follower roller 20 is located in one of the end portions of cam track slot 23a, lever 22 is positioned to tension spring 26, while one of the recesses of the drive wheel 29 is located opposite the power roll so that the same cannot engage the drive wheel 29 and rotate the same.

A manually operated member including a lever 32 has an arm 32:; which is supported for turning movement on a shaft 31 in the frame of the machine. A spring 34 is secured to arm 322 and to a fixed projection 33 in the frame, so that the

shift key member

32, 35 is held in its normal position shown in FIGS. 1 and 3.

Lever 32 has two

arms

32a, 32b respectively provided with transverse bent-over

blocking projections

32c and 32d. When the

shift key member

32, 37 is in its normal position shown in FIGS. 1 and 3, blocking projection 320 is located below the projecting pivot pin 28 and engaged by the same under the action of spring 26 which tends to turn lever 22 and drive wheel 29 which is connected by link 27 to lever 22. Such turning movement of drive wheel 29 is prevented by the projection 320 as long as the shift key 35 is not depressed. As best seen in PEG. 2, blocking projection 32a is located in the region of pivot pin 28 when shift key 35 is depressed, and also blocks movement of lever 22 and turning movement of drive wheel 29.

An arresting key member 36 with a key portion 37 is turnably mounted on a pin 40 on lever 32, and is held in position by a spring 38. A book shaped portion 361) on the arm 36a engages a stop 39 when key 37 is depressed instead of key 37. In this manner, shift key 35 is arrested in its depressed position.

Operation The carrier 2 with the type levers 4 is normally in the position shown in FIGS. 1 and 3 in which lower case characters are printed. Cam follower 20 is at one end of the cam track, buffer springs 12, 12a, are compressed, spring 26 is tensioned, and tends to turn cam 23 through lever 22 and shaft 21, but operating means 21, 22, 23, 27, 29 are prevented from turning movement towards the dead center position by the abutment of pivot pin 28 on the projection 320 of the

shift key member

32, 35. One recess of the drive wheel 29 is located opposite the power roll 30 so that the drive wheel 29 is spaced from the power means, and cannot be driven.

When shift key 35, or arresting key 37, is depressed so that lever 32 is shifted to the position shown in FIG. 2, the blocking projection 32c moves away from the pivot pin 28, and the blocking projection 32d assumes a position located in the path of pivot pin 28 during turning movement of drive wheel 29.

As soon as pivot pin 28 is released by projection 32c, lever 22 is no longer blocked, so that spring 26 turns the operating means 21, 22, 23, 27 with control member or drive wheel 29 in clockwise direction toward the dead center position in which arm 22a and spring 26 extend in a line connecting shaft 22 with stud 10. However, when lever 22 reaches the intermediate position between the end position shown in FIG. 1 and the dead center position, wheel 29 is turned through link 27 and pivot means 28 far enough to an intermediate position between the initial end position thereof and the position which drive wheel 29 assumes in the dead center position of the operating means so that one of the toothed portions of wheel 29 is engaged by the power roll 30 so that drive wheel 29 is rapidly turned until the other recess is located opposite the power roll in which position the power roll can no longer rotate drive wheel 29. During such forced turning movement of the drive wheel 29, lever 22 moves through its dead center position and arrives in its other end position when the second recess is located 28 arrives in the position shown in FIG. 2 and abuts on :12a which dampen its movement.

the blocking projection 32d of the lever 32 of the shift key 37.

Cam 23 turns with lever 22, and during the first part of the turning movement of the lever 22 from one end position to the intermediate position, the end portion of the cam track 23a moves along the cam follower so that the type lever carrier 2 is not displaced. Consequently, spring 26 does not have to produce any force for moving the type lever carrier. At the moment in which the power roll engages and drives the drive wheel 29, cam follower roller 20 is located in the curved portion of cam track 23a, and consequently the type lever carrier 2 is rapidly moved towards its other end position as long as cam follower 20 is in the curved cam track portion. When cam follower 20 is received by the other end portion of cam track 23a, the movement of the type lever carrier 2 is slowed down since the other end portion of the cam track is also tangential or extends along a circle whose center coincides with the axis of shaft 21. Near the end of the movement of the type lever carrier 2 which is guided in the frame of the machine by ball hearing means, not shown, the buffer springs 12 and 12a become effective to slow down and dampen the movement of the type lever carrier. At the end of the movement of cam 23 and lever 22, the power roll is no longer efiective since it is located opposite a recess, and spring 26 pulls lever 22 and link 27 into a position in which pivot pin 28 abuts projection 32d of the shift key lever. As explained above, this small displacement has no influence any more on the position of the type lever carrier.

If arresting key 37 was operated instead of key 35, then the type lever carrier is locked in the upper case position until key 37 is again depressed so that hook 36b releases stop 39. In any event, as soon as shift key lever 32 is released by the operator, spring 34 turns lever 32 in counterclockwise direction as viewed in the drawing, so that blocking projection 32d slides off pivot pin 28 while blocking projection 32c assumes the position shown in FIG. 1 located in the path of movement of pivot pin 28. Since lever 22 and spring 26 were turned to the position shown in FIG. 2 during the preceding operation, spring 26 now tends to turn lever 22 in counterclockwise direction to a dead center position, but in an intermediate position before the dead center position, the other toothed peripheral portion of drive wheel 29 is engaged by the power roll so that drive wheel 29 is turned in clockwise direction with pivot pin 28 moving along a circular path in the upper half of drive wheel 29 as viewed in FIG. 22 until pivot pin 28 abuts blocking projection 32c. During such turning movement of drive wheel 29, lever 22 is turned in counterclockwise direction together with cam 23 so that the cam slot is effective to move the type lever carrier to its normal lower case position in which it arrives after compression of springs 12 and The shape of cam track 23a, and particularly of the respective end portion of the cam track, elfects a slowing down of the motion of the type lever carrier near its end position, and renders the spring 26 effective to urge pivot pin 28 against the blocking projection 32]) when the power roll is located opposite a recess in the periphery of the drive wheel 22. In order to reduce the impact, the drive wheel 29 preferably consists of an elastic material such as a synthetic or natural elastomer.

, between a lower case position and an upper case position,

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.

Without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed and desired to be secured by Letters Patent is:

1. A shifting arrangement comprising, in combination, an element movable between two positions; operating means movable between two end positions, a central dead center position, and two intermediate positions respectively located between said dead center position and said end positions and operatively connected to said element for moving the same between said positions thereof when moving between said intermediate positions thereof; biasing means connected to said operating means and urging the same toward said dead center position; a member having two positions for holding said operating means in each of said end positions against the action of said biasiug means so that said operating means in each of said end positions is urged by said biasing means to move through the respective intermediate position toward said dead center position when said member is shifted from one of said positions to the other position thereof; and power means for moving said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said two positions.

2. A shifting arrangement comprising, in combination, an element movable between two positions; operating means movable between two end positions, a central dead center position, and two intermediate positions respectively located between said dead center position and said end positions, and operatively connected to said element for moving the same between said positions thereof when moving between said intermediate positions thereof; biasing means connected to said operating means and urging the same toward said dead center position; a manually operated member having two positions for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through the respective intermediate position to ward said dead center position when said member is shifted from one of said positions to the other position thereof; and power means disconnected from said operating means in said end positions of the same, and engagin said operating means in each of said intermediate positions for moving said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said two positions.

3. A shifting arrangement for a typewriter and the like comprising, in combination, an element movable oetween an upper case position and a iower case position; operating means movable between two end positions and operatively connected to said element for moving the same between said positions thereof; resilient biasing means connected to said operating means and urging the same toward a'dead center position located intermediate said two end positions; a shift key member having two positions for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through an intermediate position toward said dead center position when said shift key member is shifted from one of said positions to the other position thereof; and power roll means engaging said operating means in each of said intermediate 7 positions for moving said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said upper case position and said lower case position.

4. A shifting arrangement comprising, in combination, an element movable between two positions; operating means 'turnable between two end positions, a central dead center position, and two intermediate positions respectively located between said dead center position and said end positions, and operatively connected to said eiement for moving the same between said positions thereof when moving between said intermediate positions thereof; bias ing means eccentrically connected to said operating means and urging the same toward said dead center position; a manually operated member having two positions for holding said operating means in each of said end positions against the action of said biasing-means so that said operating means in each of said end positions is urged by said biasing means to move through the respective intermediate position toward said dead center position when said member is shifted from one of said positions to the other position thereof; and rotary power means disconnected from said operating means in said end positions of the same, and engaging said operating means in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said two positions.

5. A shifting arrangement for a typewriter or the like, comprising, in combination, an element movable between an upper case position and a lower case position; operating means turnable between two end positions and operatively connected to said element for moving the same between said positions thereof; resilient biasing means eccentrically connected to said operating means and urging the same toward a dead center position located intermediate said two end positions; a shift key member having two positions for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through an intermediate position toward said dead center position when said shift key member is shifted from one of said positions to the other position thereof; and rotary power roll means engaging said operating means in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said upper case position and said lower case position.

6. A shifting arrangement comprising, in combination, an element movable between two positions and having a cam follower; operating means movable between two end positions, a central dead center position, and two intermediate positions respectively located between said dead center position and said end positions, and including a cam having a cam track cooperating with said cam followor of said element for moving said element etween said positions, and a control member connected to said cam for movement therewith; biasing means connected to said operating means and urging the same toward said dead center position; a manually operated member having two positions engaging said control member for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through the respective intermediate position toward said dead center position when said member is shifted from one of said positions to the other position thereof; and power means disconnected from said control member in said end positions, and engaging said control member in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said two positions.

7. A shifting arrangement comprising, in combination, an element movable between two positions and having a cam follower; operating means turnable between two end positions, a central dead center position, and two inter mediate positions respectively located between said dead center position and said end positions, and including a cam turnable about an axis and having a cam track cooperating with said cam follower of said element for moving said element between said positions, said cam track having two end portions substantially concentric with said axis of said turnable cam and differently spaced from the same and an intermediate arcuate portion, and a control member connected to said cam for movement therewith; biasing means eccentrically connected to said operating means and urging the same toward said dead center position; a manually operated member having two positions engaging said control member for holding said operating means in each of said end positions against the action of biasing means so that said operating means in each of said end positions is urged by said biasing means to move through the respective intermediate position toward said dead center position when said member is shifted from one of said positions to the other position thereof; and rotary power means disconnected from said control member in said end positions, and engaging said control member in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said two position-s.

8. An arrangement as set forth in claim 7 wherein said end portions of said cam track extend substantially perpendicularly to each other.

9. An arrangement as set forth in claim 7 wherein said intermediate arcuate portion of said cam track is of sinusoidal shape.

10. An arrangement as set forth in claim 7 wherein said end portions of said cam track extend substantially perpendicularly to each other, wherein one of said end portions is spaced a smaller radial distance from the turn ing axis of said cam than the other end portion, and wherein said intermediate arcuate portion is of sinusoidal shape.

11. A shifting arrangement for a typewriter and the like comprising, in combination, an element movable between an upper case position and a lower case position and having a cam follower; operating mean-s turnable between two end positions and including a cam having a cam track having a center portion of sinusoidal shape cooperating with said cam follower of said element for moving said element between said positions, and a control member connected to said cam for movement therewith; resilient biasing means eccentrically connected to said operating means and urging the same toward a dead center position located intermediate said two end positions; a shift key member having two positions engaging said control member for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through an intermediate position toward said dead center position when said shift key member is shifted from one of said positions to the other position thereof; and rotary power roll means engaging said control member in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said upper case position and said lower case position.

12. A shifting arrangement for a typewriter and the like comprising, in combination, an element movable between an uppercase position and a lower case position 3 having a cam follower; operatingmeans movable between two end positions and including a cam having a main portion and an adjustable portion'mounted on said main portion and forming with the same an adjustable cam track slot receiving said cam follower for moving said element between said positions; resilient biasing means eccentrically connected to said operating means and urging the same toward a dead center position located intermediate said two end positions; a shift key member having two positions for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through an intermediate position toward said dead center position when said member is shifted from one of said positions to the other position thereof; and rotary power roll means engaging said operating means in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said upper case position and said lower case position.

13. A shifting arrangement for a typewriter and the like comprising, in combination, an element movable between an upper case position and a lower case position including an adjustable member and a cam follower roller mounted on said adjustable member; operating means turnable between two end positions and including a cam having a cam track slot receiving said cam follower roller for moving said element between said positions; resilient biasing means eccentrically connected to said operating means and urging the same toward a dead center position located intermediate said two end positions; a shift key member having two positions for holding said operating means in each of said end positions again-st the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through an intermediate position toward said dead center position when said shift key member is shifted from one of said positions to the other position thereof; and rotary power roll means engaging said operating means in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said upper case position and said lower case position.

14. A shifting arrangement for a typewriter and the like comprising, in combination, an element movable between an upper case position and a lower case position including an adjustable member and a cam follower roller mounted on said adjustable member; operating means turnable between two end positions and including a cam having a main portion and an adjustable portion mounted on said main portion and forming with the same an adjustable cam track slot receiving said cam follower roller and having a sinusoidal center portion and two substantially straight transverse end portions for moving said element between said positions; resilient biasing means eccentrieally connected to said operating means and urging the same toward a dead center position located intermediate said two end positions; a shift key member having two positions for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through an intermediate position toward said dead center position when said shift key member is shifted from one of said positions to the other position thereof; and rotary power roll means engaging said operating means in each of said intermediate positions for turning said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said upper case position and said lower case positions.

15. A shifting arrangement for a typewriter or the like comprising, in combination, a frame; a shiftable element mounted on said frame for movement between an upper case position and a lower case position; a cam follower secured to said shiftable element; a cam turnably mounted on said frame for turning movement between two end positions and having an arcuate cam track slot receiving said cam follower, said cam being turnable between two end positions for moving said shiftable element between said positions thereof; a lever connected to said cam for turning movement; a rotary power roll mounted in said frame; a drive wheel having two diametrically arrangedperipheral recesses and two peripheral drive portions intermediate said recesses, said drive wheel having an eccentric pivot means connected to said lever so that said drive wheel turns with said cam and said lever between two end positions in which said recesses are located opposite said power roll spaced from the same; a resilient means connected to said frame and to said lever and urging said lever to turn with said cam and said drive wheel from either of said end positions through an intermediate position toward a dead center position, said drive portions of said drive wheel engaging said power roll in said intermediate position; a shift key member operatively connected to said lever and to said drive wheel and having two positions for holding the same and said cam in either of said two end positions so that when said shift key member is shifted from one of said positions to the other position, said resilient means turns said drive wheel out of said end position until one of said drive portions is engaged by said power roll whereby said power roll turns said drive wheel and said cam through said dead center position toward the other end position until the other recess is located opposite said power roll while said shiftable element is shifted, said resilient means turning said drive wheel, said lever and said cam to said other end position.

16. A shifting arrangement for a typewriter or the like comprising, in combination, a frame; a shiftable element mounted on said frame for movement between an upper case position and a lower case position; a cam follower secured to said shiftable element; a cam turnably mounted on said frame for turning movement be tween two end positions and having an arcuate cam track slot receiving said cam follower, said cam being turnable between two end positions for moving said shiftable element between said positions thereof; a lever connected to said cam for turning movement; a rotary power roll mounted in said frame; a drive wheel having two diametrically arranged peripheral recesses and two peripheral drive portions intermediate said recesses, said drive wheel having an eccentric pivot means connected to said lever so that said control wheel turns with said team and said lever between two end positions in which said recesses are located opposite said power roll spaced from the same; a resilient means connected to said frame and to said lever and urging said lever to turn with said cam and said drive wheel from either of said end positrons through an intermediate position toward a dead center position, said drive portions of-said drive wheel engaging said power roll in said intermediate position; a shift key member having two blocking portions cooperating with said pivot means in two positions of said shift key member for holding said drive wheel and said cam in either of said two end positions so that when said shift key member is shifted from one of said positions to the other position, said resilient means turns said drive wheel out of one of said end positions until one of said drive portions is engaged by said power roll whereby said power roll turns said drive wheel and said cam through said dead center position toward the other end position until the other recess is located opposite said power roll while said shiftable element is shifted, said resilient means turning said drive wheel, said lever and said earn to said other end position in which said pivot It means abuts the other blocking portion of said shift key member.

17. A shifting arrangement as set forth in claim 16 including a shaft mounted on said frame for turning movement and supporting said lever and said cam.

18. An arrangement as set forth in claim 16 and including spring means for urging said shift key member to one of said positions thereof so that said pivot means is released by said other blocking portion when said shift key member is released by the operator.

19. A shifting arrangement for a typewriter or the like comprising, in combination, a frame; a shiftable ele ment mounted on said frame for movement between an upper case position and a lower case position; a cam follower secured to said shiftable element; a cam turnably mounted on said frame for turning movement between two end positions and having an arcuate cam track slot receiving said cam follower, said cam track slot having two end portions extending substantially concentrio to the turning axis of said cam, and an intermediate sinusoidal portion between said end portions, said cam being turnable between two end positions for moving said shiftable element between said positions thereof; a lever connected to said cam for turning movement; a rotary power roll mounted in said frame; a drive wheel having two diametrically arranged peripheral recesses and two peripheral drive portions intermediate said recesses, said drive wheel having an eccentric pivot means connected to said lever so that said control wheel turns with said cam and said lever between two end positions in which said recesses are located opposite said power roll spaced from the same; a resilient means connected to said frame and to said lever and urging said lever to turn with said cam and said drive wheel from either of said end positions through an intermediate position toward a dead center position, said drive portions of said drive wheel engaging said power roll in said intermediate position; a shift key member operatively connected to said lever and to said drive wheel and having two positions for holding the same and said cam in either of said two end positions so that when said shift key member is shifted from one of said positions to the other position, said resilient means turns said drive wheel out of one of said end positions until one of said drive portions is engaged by said power roll whereby said power roll turns said drive wheel and said cam through said dead center position toward the other end position until the other recess is located opposite said power roll while said shiftable element is shifted, said resilient means turning said drive wheel, said lever and said cam to said other end position.

20. A shifting arrangement for a typewriter or the like comprising, in combination, a frame; a shiftable element mounted on said frame for movement between an upper case position and a lower case position; buffer spring means intermediate said shiftable element and said frame for dampening the movement of said shiftable element near said upper and lower case positions; a cam follower secured to said shiftable element; a cam turnably mounted on said frame for turning movement between two end positions and having an arcuate cam track slot 12 receiving said cam follower, said cam being turnable between two end positions for moving said shiftable element between said positions thereof; a lever connected to said cam for turning movement; a rotary power roil mounted insaid frame; a drive wheel having two diametically arranged peripheral recesses and two peripheral drive portions intermediate said recesses, said drive wheel having an eccentric pivot means connected to said lever so that said control wheel turns with said cam and said lever between two end positions in which said recesses are located opposite said power roll spaced from the same; a resilient means connected to said frame and to said lever and urging said lever to turn with said cam and said drive wheel from either of said end positions through an intermediate positions toward a dead center position, said drive portions of said drive wheel engaging said power roll in said intermediate position; a shift key member operatively connected to said lever and to said drive wheel and having two positions for holding the same and said cam in either of said two end positions so that when said shift key member is shifted from one of said positions to the other position, said resilient means turns said drive wheel out of one of said end positions until one of said drive portions is engaged by said power roll whereby said power roll turns said drive wheel and said cam through said dead center position toward the other end position until the other recess is located opposite said power roll while said shiftable element is shifted, said resilient means turning said drive wheel, said lever and said cam to said other end position.

21. A shifting arrangement comprising, in combination, a supporting frame; a shiftable element mounted on said frame for movement between two end positions; spring means intermediate said shiftable element and said frame for dampening the movement of said shiftable element near said positions of the same; operating means movable between two end positions, a central dead center position, and two intermediate positions respectively located between said dead center position and said end positions, and operatively connected to said element for moving the same between said positions thereof when moving between said intermediate positions thereof; biasing means connected to said operating means and urging the same toward said dead center position; a member having two positions for holding said operating means in each of said end positions against the action of said biasing means so that said operating means in each of said end positions is urged by said biasing means to move through the respective intermediate position toward said dead center position when said member is shifted from one of said positions to the other position thereof; and power means for moving said operating means from each of said intermediate positions through said dead center position to one of said end positions whereby said element is shifted between said two positions.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A SHIFTING ARRANGEMENT COMPRISING, IN COMBINATION, AN ELEMENT MOVABLE BETWEEN TWO POSITIONS; OPERATING MEANS MOVABLE BETWEEN TWO END POSITIONS, A CENTRAL DEAD CENTER POSITION, AND TWO INTERMEDIATE POSITIONS RESPECTIVELY LOCATED BETWEEN SAID DEAD CENTER POSITION AND SAID END POSITIONS AND OPERATIVELY CONNECTED TO SAID ELEMENT FOR MOVING THE SAME BETWEEN SAID POSITIONS THEREOF WHEN MOVING BETWEEN SAID INTERMEDIATE POSITIONS THEREOF; BIASING MEANS CONNECTED TO SAID OPERATING MEANS AND URGING THE SAME TOWARD SAID DEAD CENTER POSITION; A MEMBER HAVING TWO POSITIONS FOR HOLDING SAID OPERATING MEANS IN EACH OF SAID END POSITIONS AGAINST THE ACTION OF SAID BIASING MEANS SO THAT SAID OPERATING MEANS IN EACH OF SAID END POSITIONS IS URGED BY SAID BIASING MEANS TO MOVE THROUGH THE RESPECTIVE INTERMEDIATE POSITION TOWARD SAID DEAD CENTER POSITION WHEN SAID MEMBER IS SHIFTED FROM ONE OF SAID POSITIONS TO THE OTHER POSITION THEREOF; AND POWER MEANS FOR MOVING SAID OPERATING MEANS FROM EACH OF SAID INTERMEDIATE POSITIONS THROUGH SAID DEAD CENTER POSITION TO ONE OF SAID END POSITIONS WHEREBY SAID ELEMENT IS SHIFTED BETWEEN SAID TWO POSITIONS.