US3313388A

US3313388A - Control mechanism for type bars including a pivotable rake

Info

Publication number: US3313388A
Application number: US493833A
Authority: US
Inventors: Aebi Otto
Original assignee: Paillard SA
Current assignee: Paillard SA
Priority date: 1965-06-02
Filing date: 1965-10-07
Publication date: 1967-04-11
Anticipated expiration: 1984-04-11
Also published as: NL6607296A; DE1277275B; CH416689A; AT262336B; ES326525A1; GB1082702A

Description

April 11, 1967 o. AEBI 3,313,388

CONTROL MECHANISM FOR TYPE BARS INCLUDING A PIVOTABLE RAKE Filed Oct. 7, 1965 2 Sheet's Sheet 1 INVENTOR ATTORNEY Aprifl 11, 1967 o. AEBI CONTROL MECHANISM FOR TYPE BARS INCLUDING A PIVOTABLE RAKE 2 Sheets-Sheet 2? Filed Oct.

INVENTOR A ORNEY United States Patent 3,313,333 CONTROL MECHANISM FOR TYPE BARS INCLUDING A PIVOTABLE RAKE Otto Aebi, Yverdon, Switzerland, assignor to Paiilard S.A., Vaud, Switzerland, a corporation of Switzerland Filed Oct. 7, 1965, Ser. No. 493,833 Claims priority, application Switzerland, June 2, 1965, 7,708/65 3 Claims. (Cl. 197-74) The present invention relates to a control mechanism for the type bars of a typewriter. The type bars are pivoted on a basket which may be removed by the operation of a motion lever to change from typing in lower case type to typing in upper case type. The type bars are each controlled from a key lever by means of a lever pivoted on a movable rake, one end of this lever being connected to the key lever by a draw-rod, the other end of this lever being connected to the type bar by a second draw-rod. The movement of the rake is controlled by the operation of a motion lever, so as to substantially to preserve the same relative disposition between the different connecting members between the key lever and the type bar for the striking of lower case and upper case type.

For such mechanisms, one always searches for the most simple means for establishing the kinematics involved. The movement imparted to the key lever must be transmitted to the type bar by a minimum of elements, which are simple to manufacture and are of low inertia. Numerous solutions are known which satisfy, more or less, these criteria.

The problem is rendered more intricate by the fact that, on the one hand, the movement of the key levers which pivot about a horizontal axis must be transmitted to the type bars which pivot on an axis having the shape of a ring segment.

Moreover, the basket carrying the type bars effects a translatory motion when passing from small letters to capitals. Means must therefore be provided so that, during this movement, the geometry of this kinematic chain is not altered. In order to avoid this disadvantage, most manufacturers employ an intermediate lever placed on the basket. This lever also pivots on an axis in the shape of a ring segment and is situated in the same plane as the type bar. This solution is disadvantageous because it tends to make the basket heavy and to increase its bulk. This last point is not compatible with the minimum bulk conditions required for certain portable typewriters. Certain manufacturers have by-passed this bulk ditficulty by various means but at the price of other disadvantages, such as bent key levers instead of flat levers, additional pivoting points for key levers i.e., three or four levers instead of a single one.

Other manufacturers have provided, in the kinematic chain connecting the key lever to the type bar, an intermediate lever pivoted on a movable rake which is moved by the movement of the motion lever. Since the movements of the basket and of the rake are not parallel, it is necessary to provide a curved rake, on the one hand, and the two connecting joints of the draw-rod connecting the type bar and the lever pivoted on the rake cannot be chosen arbitrarily, on the other hand.

The mechanism according to the present invention is characterized in that said rake is mounted so that the pivoting point of said lever pivoted on the rake moves on a line parallel to the direction of displacement of the basket from a first to a second position and vice versa during the operation of the motion lever.

The accompanying drawing shows, diagrammatically and by way of example, one embodiment of the subject of the invention.

FIG. 1 is a side view, with partial sections, of this embodiment.

FIG. 2 is a partial view on a larger scale.

The mechanism shown includes type bars 1 pivoting at 2 in a movable basket 3. This basket 3 is mounted on the base 4 by links 5, in order that it may move its axis from 2 to 2' as indicated in FIG. 2. The movement is controlled by an eccentric 7, the pin 8 of which cooperates with a fork 9 of the basket. The eccentric 7 is controlled from a motion or shift lever 10 by a kinematic chain including a draw-rod 11, a lever 12 pivoted at 13, a drawrod 14 and a toothed segment 15 pivoted at 16.

The type bars 1 are controlled from key levers 17 pivoted at 18 by a kinematic chain including a draw-bar 19, a lever 20 pivoted at 21 on a movable rake- 22 and a draw-rod 23. The rake 22, which pivots at 24, is controlled from the lever 12 by a link 25 pivoting at 26 on the rake 12 and at 21 on the lever 22. Also provided are springs 27 for the return of key levers 17.

As shown in FIG. 2 of the drawing, the kinematic striking chain is disposed so that upon actuation of the motion lever 10, the pivot points 21 of the levers 20 move on a line parallel to the direction of displacement of the basket 3 as it moves from its first to its second position and vice versa. This arrangement permits use of a straight rake 22 which is easier to manufacture than known rakes which are bent.

The operation of the mechanism is as follows:

When one presses on the key of the lever 10, its move ment is transmitted to the eccentric 7, thev pin 8 then driving the basket 3 over a distance equal to the distance between the pins 2 and 2. The passage from position 2 to position 2', shown in dotted lines, of the axis of the type bars corresponds to the passage from lower case type to upper case type. The

members

11, 12, 14, 15 of the kinematic chain are then in the positions 11, 12', 14 15', shown in dotted lines.

In order not to alter the geometry of the members of the kinematic striking chain, the pivoting point 21 of the lever 20 is moved to 21' in a movement parallel to the direction of movement of the basket 3 and the pivots 22' and of the same distance. The members 19, 20, 23 of the kinematic striking chain then occupy the positions 19, 20', 23, shown in dotted lines. Independently of the fact that the rake 22 is straight, another advantage of the parallel movement of the axes 2 and 21 resides in the fact that the attachment point of the draw-rod 23 to the lever 20 may be chosen arbitrarily about the point 21 at the place which is the most convenient in order to obtain the best acceleration conditions of the type bar and of the touch of the keyboard.

I claim:

1. In a typewriter, a control mechanism for the type bars comprising a basket movable from a first position into a second position, type bars pivoted on said basket, the pivots of said type bars being located on an arcuate line, control means including a shift lever for shifting said basket from a first position into a second position and vice versa, key levers for actuating said type bars, a movable rake, levers pivoted on said rake, links connecting each key lever to its respective rake lever and connecting each rake lever to its respective type bar, said control means comprising connecting means displacing said rake in relation to the shifting of said basket from its first to its second position and vice versa by operation of said shift bar, said rake being mounted so that the pivoting points of said levers pivoted on the rake are located, in the first and second position of said basket, on lines parallel to the direction of the displacement of said basket from its first into its second position.

2. A control mechanism according to claim 1, wherein said rake is straight, said levers carried by said rake being parallel to each other and pivoted on a straight axis.

3. .A control mechanism according to claim 2, Wherein said rake is pivotally mounted on a part of the typewriter, and the connecting means displacing said rake comprises 5 a link connected to said motion lever.

Hess 197-29 Helmond 197-74 Thyer 19774 X Nunderlich et al 19727 Yaeger 19727 Ryan et a1 19717 ROBERT E. PULFREY, Primary Examiner.

E. S. BURR, Assistant Examiner.

Claims

1. IN A TYPEWRITER, A CONTROL MECHANISM FOR THE TYPE BARS COMPRISING A BASKET MOVABLE FROM A FIRST POSITION INTO A SECOND POSITION, TYPE BARS PIVOTED ON SAID BASKET, THE PIVOTS OF SAID TYPE BARS BEING LOCATED ON AN ARCUATE LINE, CONTROL MEANS INCLUDING A SHIFT LEVER FOR SHIFTING SAID BASKET FROM A FIRST POSITION INTO A SECOND POSITION AND VICE VERSA, KEY LEVERS FOR ACTUATING SAID TYPE BARS, A MOVABLE RAKE, LEVERS PIVOTED ON SAID RAKE, LINKS CONNECTING EACH KEY LEVER TO ITS RESPECTIVE RAKE LEVER AND CONNECTING EACH RAKE LEVER TO ITS RESPECTIVE TYPE BAR, SAID CONTROL MEANS COMPRISING CONNECTING MEANS DISPLACING SAID RAKE IN RELATION TO THE SHIFTING OF SAID BASKET FROM ITS FIRST TO ITS SECOND POSITION AND VICE VERSA BY OPERATION OF SAID SHIFT BAR, SAID RAKE BEING MOUNTED SO THAT THE PIVOTING POINTS OF SAID LEVERS PIVOTED ON THE RAKE ARE LOCATED, IN THE FIRST AND SECOND POSITION OF SAID BASKET, ON LINE PARALLEL TO THE DIRECTION OF THE DISPLACEMENT OF SAID BASKET FROM ITS FIRST INTO ITS SECOND POSITION.