DE3316173A1 - ADJUSTABLE SEAT DEVICE WITH DOUBLE LOCK - Google Patents

Description

^ ₁ . ... r. ... ¹⁰ May 2, 1983

DipUng.W.DaMke L / C / kr

Dipl.-Ing. H.-]. Lippert

Patent attorneys
Frankenforster Strasse 137
5060 Bergisdi Gladbach A

Lear Siegler, Inc. Livonia, Michigan / USA

" Adjustable seat device with double locking "

The invention relates to a seat device for Vehicles and in particular a seat device for vehicles, in which the front and the rear part of a seat support are independently adjustable in height relative to the lower part.

In the prior art, seat devices that can be adjusted by hand are known in which the front and the rear part of a seat support independently of one another in height relative to a lower part are adjustable. For example, from US Pat. No. 3 ^ 60,793 a device is known in which a Lower part and a seat support by at least two lever arms are connected to each other. the Lever arms are each pivotable at points offset in the longitudinal direction with the lower part and the Seat support connected so that the angular position of each lever arm the height either between the front or the rear part of the seat support and the lower part. The lever arms can be locked in desired angular positions by means of a locking device which comprises two essentially horizontal locking plates. The latch plates are pivotable about an essentially vertical axis

bar to get into teeth on the inward-facing end

ι to be able to intervene in the lever arms. An operating macaw is connected to the locking plates, so that an optional disengagement of the locking plates from the corresponding lever arms is made possible.

A seat device with at least two lever arms is also known from US Pat. No. 3,692,271, which are pivotably mounted between a lower part and a seat support and which extend inwards extend towards each other, as well as with two locking plates that are pivotable for rotation about their to the base transverse axes are connected to the seat support and which can optionally snap into the inwardly extending ends of the lever arms, to enable their rotation in the coupled state. A control rod is pivotable with the Seat carrier connected and is coupled to the locking plate by means of a lost motion connection in such a way that that the rotation of the control rod about its transverse axis a pivoting of one or the other locking plate about its transverse axis and thus a disengagement of one causes the locking plates from their corresponding lever arm. The lever arms have beveled notches or slotted, and each locking plate is

_{2 & provided} with a tooth that fits into the notches so that when the locking plate is turned, the tooth is pulled out of the beveled slot.

From US-PS 3,669,398 an adjustable seat _n device with two sets of levers on each Known side of the facility. On opposite sides of the seat assembly are control rods and Locking plates attached so that the levers can be pivoted to adjust the height of the seat supports. In the rear part of the device a torsion spring is connected to the levers.

The torsion spring forces the rear levers to rotate in such a way that the rear of the seat support is raised. Other seating arrangements of the general manner in which this invention relates

b, U.S. Patent 3,662,984, U.S. Patent 3,572,624, U.S. Patent 3,110,962, U.S. Patent 3,181,831, U.S. Patent 3,405,900 and U.S. Patent 3,055,627.

An object of the present invention is the sheep! 0 Fung an improved adjustable seat assembly having a locking device which is uncomplicated in manufacture, installation and operation, and generates the in the coupled state a large and in the decoupled state a small amount of frictional 2 _& resistant .

Another object of this invention is to provide an improved adjustable seat assembly having a locking device which is easily built, _"n few moving parts having but having simultaneously the required strength and closing ability to ensure an efficient operation of the seat device.

Another object of the invention is to provide an improved adjustable seat assembly with a locking device that is relatively easy to adjust.

In accomplishing the above objects and other objects of this invention, an adjustable Seat assembly constructed in accordance with the present invention includes a base, a Seat support and a first and a second sector-shaped lever arm, each of which is pivotable one end of the base to rotate around one to

Lower part transverse axis are connected. The other ends of the lever arms extend after inside to each other. A cross bar assembly connects the first and second lever arms in FIG In the middle of the ends of these points with the seat support at points offset in the longitudinal direction the seat support to adjust the height between the offset points and the lower part independently of each other by rotating the lever arms

! O to reach. For rotations around their respective A first and a second locking plate are pivotably connected to the seat support and transverse axes can optionally snap into the other ends of the first or the second lever arm to a To prevent rotation of those when engaged. For rotations around their respective transverse axes a first and a second cam disk are also pivotable at points in the middle of their ends connected to the seat support and can optionally be used in the engage the first or second locking plate, to close the first and the second locking plate with the first and the second lever arm, respectively lock. A single control rod is pivotally connected to the seat support and has a lost motion connection with the first and second Cam disc on. A control is attached to the control rod for rotating the control rod so Both locking plates can optionally disengage from the lever arms · The other ends of the lever arms are with a first plurality of teeth and the locking plates with a second plurality of teeth designed such that an optional engagement of the second plurality of teeth in each part of the first plurality of teeth is possible in each case on the corresponding lever arms. The first and

the second lever arm are each in a third

14th A large number of angular positions can be locked.

The first and the second lever arm are preferably arranged adjacent to one side of the lower part, and the third and fourth lever arms are in laterally corresponding relation to the first and to, respectively the second lever arm arranged adjacent to the other side of the lower part. The third and fourth lever arms are pivotable with the at one end ίο Lower part connected for rotation about their transverse axes. A pre-stressed first and second force element connects the first and the second lever arm with the third or with the fourth lever arm to their Coordinate rotations

Likewise, the second torsion element is preferably connected to a spring compensation device as a counterweight for rotating the second torsion element.

The objects, features and advantages of the present invention are readily apparent from the following detailed description in conjunction with the accompanying drawings.

Fig. 1 shows the side view of an illustrative embodiment of the invention in a low position.

Fig. 2 shows the device from Fig. 1 in

an elevated position.

Fig. 3 shows the plan view of this embodiment.

The adjustable seat assembly shown in FIGS. 1 to 3 of the construction drawings comprises a seat assembly Lower part 10, which is intended for mounting on the floor 11 of a vehicle. A seat support 12 carries the seat 14 with the backrest 16. The height adjustment between the front and the rear Part of the seat support 12 and the lower part 10 can be regulated by means of an adjusting device 18, which is arranged between the lower part 10 and the seat support 12.

The adjusting device 18 comprises two sector-shaped lever arms 20 and 22, the lever arm 20 has a narrower outer end part, about which it connects with the Lower part 10 by means of a bolt or a rivet 23, which passes through a kinked mounting bracket 24 with a formed therein Groove 25 is provided and which receives the bolt 23 to an angular adjustment of the lever arm 20 relative is connected to the lower part 10 to enable a transverse axis to the lower part 10. Of the Lever arm 20 is independent of seat support 12 in FIG. 28 by means of a bolt 29 as shown in FIG. 3 pivotally connected. The arched, inwardly straightened the end of the lever arm 20 1st with a more number of teeth 30, preferably 15 in number, which lock the lever arm 20 allowed in one of the many angular positions relative to the lower part 10.

Similarly, the lever arm 22 is at its outer end

with the lower part 10 by means of a bolt or a rivet 31 »which passes through a kinked fastening carrier 32, the one in it has formed groove 33 and which receives the bolt 31, pivotally connected. As in Fig. 3

shown, the lever arm 22 is shown in FIG Pin or a bolt 34 can be pivoted independently connected to the seat support 12. The lever arm 22 is at its curved, inwardly directed end

b de formed with a plurality of teeth 36 which correspond to the teeth 30 on the lever arm 20.

The lever arms 20 and 22 each carry a bolt 37, which is in the middle between their correspond the pin 28 or 35 and their curved, inward facing ends. The bolt 37 extends through the lever arms 20 and 22 and moves in curved grooves (not shown) which are formed on one side of the seat support 12 to the

Movement of the lever arms 20 and 22 relative to their

to stabilize and limit the corresponding locking plates. This is done after the following Executions described in more detail.

2Q The rotatable connections between the lever arms 20 or 22 and the seat support 12 are arranged offset in the longitudinal direction. Accordingly, the lever arm 20 controls the height of the front part of the Seat support 12 and the lever arm 22 the height of the

Rear part of the seat support 12.

In order to lock the lever arm 20 in a desired angular position, a locking plate 40 is by means of a rivet 42 for rotary movements about an axis which is also located transversely to the lower part 10 with the _g0 Seat support 12 connected. The locking plate 40 is formed with a plurality of teeth 44, preferably 5 in number, for engaging or a Engaging any desired portion of the plurality of teeth on lever arm 20 is matched.

A similar latch plate 46 is pivotally connected to seat support 12 at 45 for rotational movement UJB to allow a horizontal transverse axis. The locking plate 46 carries 5 teeth 50 which are for engagement In each part of the teeth 36 on the lever arm 22 are formed to permit rotation of the lever arm 22 in the so to prevent locked state. Preferably, teeth 30 and 36 have a tooth tip angle of about 55 ° / and the spaces between the! 0 teeth have an angle of about 60 ° to a To allow easy extraction of the teeth 44 and 50 from the teeth 30 and 36, if a decoupling of the special lever arm-locking plate combination is desired.

By equipping the locking plate with 5 locking teeth, the amount of surface that performs the locking function is increased significantly by one coherent locking between the locking plates

_or and the lever arms.

A close lock between the locking plates 40 or 46 and the corresponding lever arms 20 and 22 are ensured by the cam disks 49 and 51, respectively. The cam disk 49 is shown in FIG pivotally connected to the seat support 12 for rotation about a transverse axis. Similarly, in Fig. 55, cam 51 is for rotation about a transverse axis connected to the seat support 12 so as to be pivotable in the transverse axis offset in 53.

Each of the latch plates 40 and 46 have two offset fingers 57 and 59 that receive one end of their respective cam. Sliding contact of the cam disks 49 or 51 with the 5

corresponding fingers 57 cause an unlocking

ment, while sliding contact of the cam discs 49 and 51 with their respective fingers 59 a Cause locking.

b A coupling of the locking plate> r 40 or 46, the Lever arms 20 and 22 and the cam ^ friction 49 and 51 is controlled by means of a flat control rod 52, which are also connected to the seat support 12 in 54 such that they can rotate about a transverse axis is. The control rod 52 is provided with two outwardly extending, elongated arms 56 and 58 designed to engage in the cam disks 49 and 51, respectively. The control rod 52 carries a rivet 60 to adjust the swivel connection between the control

_lf) rod 52 and one end of an actuating arm 66 to effect. This is described in more detail after the following.

As best shown in F ^ g. 3 have seen the ₂ Q cam discs 49 and 51 to bent arms 63 and 65 extending from the respective pin 53 or 55 upwardly and inwardly. The terminal ends of a tension spring 64 coupled to the arms 63 and 65 such that the cam _nu slices for coupling to the corresponding fingers 59 of the lock plates 40 and 46 forced. Accordingly, the latch plates 40 and 46 are urged outwardly away from each other to snap into their respective lever arms. Rotation of the control rod 52 in one direction about the pins 54 causes one of the cams to rotate about its transverse axes and press against the fingers 57 of their respective locking plates and, during the rotation, disengage the locking plate from its respective lever arm. At the same time, the other cam disc remains with the finger 59 of its locking

plate coupled in order to remain coupled with its corresponding lever axis during the rotation. the Pivoting movement of the control rod 52 is determined by the control knob of the operating arm 66,

■ which can also be pivoted by means of the rivet 42 is connected to the seat support 12 and which extends from the adjusting device 18 outward and toward the outside extends above to provide a user of the seat 14 to access. The inwardly directed end of the actuating arm 66 alternatively rotates the control rod 52 in opposite directions Directions about their pin 54 due to the pivoting movement of the arm 66 about the pivot joint, the by the rivet 42 was created.

During the operation of the device shown in FIGS. 1 to 3, the setting device 18 permits a height adjustment of the front and the rear part of the seat support 12 relative to the lower part 10 independent of each other. The seat support 12 is between the lowered position shown in FIG. 1 and the raised position shown in Fig. 2 adjustable. To enable this setting range, the actuating arm 66 can, for example, initially by the Rivet 42 rotated counterclockwise which results in a clockwise rotation of the control rod 52 about the pin 54. This results in a release of the preloaded cam disk 49, as well as, meanwhile, a proof to the Finger 57 of the locking plate 40, so that the locking plate 40 is disengaged from the lever arm 20 below Entrainment of the teeth 44 from the upper set of teeth 30 on the lever arm 20. The lever arm 20 is now free pivotable about the mounting bracket 24 by means of Bolt and groove combination, which increases the Front part of the seat support 12 with the help of the front

its torsion bar spring 70, which will be described in more detail in connection with the following. The user of the seat can thus support this operation simply by leaning back in the backrest 16.

After the seat support 12 has been placed at the desired height relative to the lower part 10, the Actuating arm 66 released, and the spring 64 forces the cam disk 49 to press against the Fingers 59, and accordingly the latch plate 40 is outwardly for engaging a corresponding one Set of teeth urged on lever arm 20. As far as the device 18 is locked again, as for example shown in Fig. 2.

Rotation of the actuator arm 66 about the rivet 42 in the counterclockwise direction is influenced due to the lost motion connection between the control rod 52 and the cam 51 does not require the coupling between the locking plate 46 and the lever arm 22. One Rotation of the actuating arm 66 clockwise performs a corresponding function, depending on If you want to raise or lower the rear part of the seat support with the help of the rear Torsion bar spring 72 permitted. This is described in more detail below. The user of the The seat can support this operation by bending forward in the seat 14.

As shown in Fig. 3, there is a second adjuster 18 'on the laterally opposite side of the seat support 12 and the adjustment device 18 arranged. The adjuster 18 'includes a second pair of lever arms 20' and 22 ', the outer one

,; Ends pivotable with a lower part 10 'by means of

Mounting brackets 24 'and 32' are connected. the

Central parts of the lever arm 20 'and 22' are by means of Bolts 29 'and 34' are pivotally attached to the opposite side of the support bracket 12. Ub the How the adjusting devices 18 and 18 'work to synchronize, the lever arms 20 and 2o * Pleaseis a rod-like torsion element or a front torsion bar spring 70, which extends transversely between the lever arms 20 and 20 *, connected to one another. The torsion bar spring 70 can be welded or otherwise suitably connected to the lever arms 20 and 20 'and is pivotally attached to bolts 28 and 28 * to pivot connection 28 as previously described on both To allow sides of the seat support 12.

Similarly, lever arms 22 and 22 'and bolts 34 and 34' are similar by means of a similar one Torsion element or a rear torsion bar 72 connected.

Accordingly, rotation of the actuator arm 66 to pivot the control rod 52 causes the cams 49 and 53 to disengage from their respective locking plates y and consequently rotate the lever arms on either side of the apparatus shown in FIG. Upward rotation of the lever arms 22 and 22 'is supported by the prestressed torsion bar spring 72.

On the torsion bar spring 72 are two spring holding arms or spring suspensions 74 and 74 offset from one another 76 attached. The opposite ends of the torsion springs 78 and 80 are on the suspensions 74 and 76, and the mounting brackets 75 and

, -, c 77 are rigid on opposite sides of the seat support 12 near the front of the seat attached. The springs 78 and 80 form a counterpart

weight to rotate the torsion bar spring 72, so that the seat device and in particular the back part of the Seat assembly can be adjusted in height in a soft and efficient manner.

Although not shown, the lower parts 10 and 10 'can be provided with guide rails for adjusting the seat support 12 in the longitudinal direction relative to the floor 11 of the vehicle on which it is mounted from « be allowed. Between the upper and the lower rail part, a suitable low-friction Sliding material can be arranged to facilitate sliding in the longitudinal direction.

Summa sumarum, the invention was related to a vehicle seat described in which the front and rear parts of a seat support relative to a seat lower part independently in height by means of selective operation of a single button

_on tigungsarms can be set, which is used to lock and unlock the device that supports the seat relative to a lower part. Furthermore, the seat device can be adjusted in the longitudinal direction by means of guide rails that are mounted on the vehicle floor.

Although one of our preferred versions of the adjustable seat device has been shown experts in this technical field will find various alternative constructions

tion proposals and designs for the implementation of the invention defined in the claims recognize in practice.

Blank page

Claims (10)

Dipl, l " _g .W.Dohlke * Ιι * 11 ¹⁹⁸³ Dipl.-Ing. H.-J. Lippert Patent Attorneys Frankenforster Straße 137 Bergisch GladbadS λ Lear Siegler, Inc. Livonia, Michigan / USA Claims 1 adjustable seat arrangement with a lower part, and a seat support, characterized by a first (20) and a second (22) sector-shaped lever arm, each at one end for rotation about one to the Lower part (10) transverse axis are pivotably connected to the lower part (10), the other ends of the lever arms (20, 22) after extend inside and towards each other, a cross bar device, each of the first (20) and the second lever arm (22) at points located in the middle of their ends pivotably with the seat support (12) at ver in the longitudinal direction set places on the seat support (12) connect to make the strokes between said offset points and the base (10) by means of rotation to be able to adjust the lever arms (20, 22) independently of one another, 3Q a first (40) and a second locking plate (46), those for rotation about their respective transverse axes (42, 45) are pivotally connected to the seat support (12) and optionally to the other ends of the first (20) or the second lever arm (22) can engage to prevent their rotation when engaged, a first (49) and a second cam disc (59) pivotable for rotations about their respective transverse axes (53, 55) at the center their ends are connected to the seat support (12) and optionally with the first (40) or with the second locking plate (46) can engage to the first (40) or the second To lock the locking plate (46) with the first (20) or with the second lever arm (22), a single control rod (52) pivotally connected to the seat support (12) and the is slidably connected to the first (49) and second cams (51), an actuator (66) adapted to rotate the control rod (52) and for optional disengagement both locking plates (40, 46) from the lever arms (20, 22) are connected to the control rod (52), the other ends of the lever arms (20, 22) each having a first plurality of teeth (30, 36) and the locking plates (40, 46) each with a second plurality of teeth (44, 50) are equipped so that an optional engagement of the second plurality of teeth (44, 50) in each part of the first plurality of teeth (30, 36) on the corresponding lever arms (20, 22) is possible, the first (20) and the second lever arm (22) can be locked in a third plurality of angular positions. 2. Device according to claim 1, characterized by a spring device (64) which the cam disk (49) 51) for Engaging in the locking plates (40, 46) for a positive locking of the locking plates (40, 46) preloaded with the lever arms (20, 22). 3. Device according to claim 1, characterized in that therein the Control rod (52) is pivotably mounted about a transverse axis (54), and that the transverse axes therein (53, 55) of the cam disks (49, 51) in one Level up to the transverse axis (54) of the control rod (52) are arranged offset. 4. Device according to claim 2, characterized in that each said cam disks (49, 51) has an era (63, 65) extending therefrom, said arms (63, 65) being staggered and said spring means therein ΐδ (64) for biasing the arms (63, 65) of the cam disks (49, 51) connecting them to one another to engage them in said locking plates (40, 46) and thus the teeth (44, 50) of said locking plates (40, 46) to snap into said teeth (3K), 36) of said first (20) and said second lever arm (22) to force. 5. Device according to claim 1, characterized in that each said first and said second locking plates (40, 46) are two staggered Finger (57, 59) for receiving one end of the corresponding cam disk (49, 51), said cams (49, 51) during their rotation in the locking plates (40, 46) intervene. 6. Device according to claim 1, 2, 3 »4 or 5, characterized in that that therein the lever arms (20, 22) adjacent to one side of the lower part (10) are arranged, and that the device further a third (20 ¹ ) and a fourth lever arm (22 ¹ ) arranged adjacent to the other side of the lower part (10 *) in laterally corresponding relationship to the first (20 ) and the second lever arm (22), the third (20 ·) and the fourth lever arm (22 *) being pivotable for rotations about their transverse axes (29 '»3 ^ ·) at one end with the un- ίο the lower part (10) are connected. The other ends of the lever arms (20 ', 22') extend inwardly towards one another. The third (20 ¹ ) as well as the fourth lever arm (22 ') are each by means of a pivot connection with the seat support (12) at points offset in the longitudinal direction on the seat support (12) connected to the height between said points and the base (10 ·) by turning the Lever arms (20 ·, 22 ') can be adjusted independently of one another. A first (70) and a second torsion element (72) connect the first (20) and the second lever arm (22) with the third (20 ·) or the fourth lever arm (22 ') »about their rotations to synchronize. 7. Device according to claim 6, further characterized by a spring compensation device (78, Θ0), which is connected to said second torsion element (72), to the rotation to compensate for said second torsion element (72). 8. Adjustable seat assembly having a lower part and a seat carrier, characterized by a first (20) and a second if (22) the sector-shaped lever arm which at one end for rotation about a to the lower part (10) ι transverse axis are pivotably connected to the lower part (10), the other ends of the Lever arms (20, 22) extend inwardly and towards one another, a transverse rod device which can pivot with the first (20) and the second lever arm (22) at points located in the middle of their ends connect the seat support (12) at points offset in the longitudinal direction on the seat support (12) in order to achieve the Height between said offset points and the base (10) by means of rotation of the lever arms (20, 22) to be able to set independently of each other, a first (40) and a second locking plate (46), which are pivotably connected to the seat support (12) for rotation about their respective transverse axes (42, 45) and can optionally engage with the other ends of the first (20) or the second lever arm {22) to enable them to rotate Condition to prevent first (49) and second cams (59) which are pivotable for rotation about their respective ones Transverse axes (53, 55) are connected to the seat support (12) at points located in the middle of their ends are and optionally with the first (40) or with the second locking plate (46) can engage to the first (40) and the second locking plate (46) with the first (20) and with the second lever arm (22) to lock conclusively, each of the said cam disks (49, 51) one of them extending arm (63 »65), and wherein said arms (63, 65) are arranged offset from one another, a single control rod (52) that is pivotable is connected to the seat support (12) and the is slidably connected to the first (49) and second cams (51), ι an actuating device (66) which is used to rotate the control rod (52) and for optional disengagement both locking plates (40, 46) from the lever arms (20, 22) are connected to the control rod (52), the other ends of the lever arms (20, 22) each having a first plurality of teeth (30, 36) and the locking plates (40, 46) each with a second plurality of teeth (44, 50) are equipped so that an optional engagement of the second plurality of teeth (44, 50) in each part of the first plurality of teeth (30, 36) on the respective lever arms (20, 22) is possible, each of the first (20) and the second lever arm (22) in a third plurality of Angular positions can be locked, a spring device (64) for biasing the the arms (63, 65) of the cam disks (49, 51) interconnects to the cam discs (49, 51) for engaging in said locking plates (40, 46) and thus the teeth (44, 50) of said locking plates (40, 46) to snap into place into the teeth (30, 36) of said first (20) and said second lever arm (22) to force. 9. Adjustable seat device with a lower part and a seat support, marked by a first (20) and a second eector-shaped lever arm (22), which are used for rotation pivotable about an axis transverse to the lower part (10), each at one end with the lower part (10) are connected, the other ends of the lever arms (20, 22) extending inwardly towards one another, and wherein the lever arms (20, 22) are arranged adjacent to one side of the lower part (10), ι a third (20 *) and a fourth lever arm (22 *), which are arranged adjacent to the other side of the lower part (10 ¹ ) in a corresponding lateral relationship to the first (20) and to the second lever arm (22), in each case the third (20 ·) and the fourth lever arm (22 «) are pivotably connected at one end to the lower part (10 ·) _{for rotation about their transverse axes (29 * f 34 '), and the other ends of the lever arm} arms (20, 22 ') extend inward towards each other, a pivot connection, each of the third (20 ¹ ) and the fourth lever arm (22 ·) at points offset in the longitudinal direction on the seat support Connect (12) to the seat support (12) to adjust the height between said offset points and adjust the lower part (10 ·) independently of one another by rotating the lever arms (20 ', 22') to be able to Torsion elements (70, 72,) that support the first (20) or the second lever arm (22) with the third (20 *) or the fourth lever arm (22 *) with one another connect to coordinate their rotations, a cross-bar connection, each of which connects the first (20) and the second lever arm (22) at the center of their ends with the seat support (12) at longitudinally offset points on the seat support (12) pivotably to one another, by the height between the said places and the lower part (10) Adjust the rotation of the first (20) and the second lever arm (22) independently of one another, first (40) and second latch plates (46) pivotable with the seat support for rotation about their respective transverse axes (42, 45) ι (12) are connected and which can optionally snap into the other ends of the first (20) and the second lever arm (22) to prevent their rotation in the locked state, b a spring device (64) for biasing the Cam disk (49, 51) so that they engage in the locking plates (40, 46), and thus the Locking plates (40, 46) with the first (20) and with the second lever arm (22) conclusively ver bolt, a first (49) and a second cam (51) which are rotatable about their respective ones Transverse axes (53, 55) pivotable with the seat support at points located in the middle of their ends (12) are connected and each is optional in the first (40) or in the second locking plate (46) can intervene to the first (40) or the second locking plate (46) with the first (20) or with the second lever arm (22) lock, a single control rod (52) pivotally connected to the seat support (12) and which is slidably connected to the first (49) and to the second cam disc (51), an actuating device (66) for rotating the control rod (52) and for optionally disengaging both locking plates (40, 46) from the first (20) or from the second lever arm (22) is connected to the control rod (52), the other ,, _n ren ends of the first (20) and the second lever arm (22) each equipped with a first plurality of teeth (30, 36) and the locking plates (40, 46) each equipped with a second plurality of teeth (44, 50) so that an optional engagement of the second plurality of teeth (44, 45) in any part of the first plurality of teeth (30, 36) on the corresponding lever arm (20, 22) is possible, with the first (20) as the second lever arm (22) can be set in a third plurality of angular positions. 10. The device according to claim 9, further g e identification, by a spring compensation device (78, 80) which is connected to said second torsion element (72) to counterbalance the rotation of said second torsion element (72).