Operating mechanism for a furniture part including a shape memory element
In an operating mechanism for a moving a furniture part via a drive arrangement including a shape memory element, the shape memory element is connected between a stationary support point and a part to be moved via a force- or form-locking coupling structure having a limited holding force to prevent over-stressing the shape memory element.
This is a Continuation-In-Part Application of pending international patent application PCT/DE2009/000927 filed Jul. 2, 2007 and claiming the priority of German patent application 10 2008 030 933.8 filed Jul. 2, 2008.
BACKGROUND OF THE INVENTIONThe invention resides in an operating mechanism for moving a furniture part, that is movable with respect to a stationary furniture part by means of a drive arrangement including a shape memory element toward an opening position or a closed position. The drive arrangement is mounted to one furniture part and abuts the other furniture part by way of a coupling element. The drive arrangement includes as drive element a shape memory element which shrinks upon heating and which is arranged between the coupling element and a fixed support location opposite the drive arrangement.
DE 10 2008 027 541 discloses such an operating mechanism for example for opening drawers and furniture doors.
It is the object of the present invention to provide an operating mechanism for opening or closing furniture parts including a drive structure which includes at least one shape memory element wherein however the shape memory element actuating the drive structure is protected from overload by faulty or erroneous operation.
SUMMARY OF THE INVENTIONIn an operating mechanism for a moving a furniture part via a drive arrangement including a shape memory element, the shape memory element is connected between a stationary support point and a part to be moved via a force- or form-locking coupling structure having a limited holding force to prevent over-stressing the shape memory element.
In the operating mechanism according to the invention includes a drive arrangement wherein an operating force is generated by one or more shape memory elements providing for a certain linear movement. The linear movement is transmitted directly, or by way of a drive structure, to the furniture part which is movably supported by the stationary furniture part on which the movable furniture part is supported and which carries the drive arrangement. The shape memory element or elements may be one or several times re-directed by pulleys or guide tracks.
The drive arrangement of the operating mechanism may be for example a lever drive, a gear drive a gear rack drive or a similar device.
For obtaining a linear stroke which acts counter to the actuating stroke of a shape memory element for example a spring drive, a gravity drive or a second shape memory element may be used.
The stationary parts of a furniture piece are for example the cabinet body, the desk body or also a door frame. The movable furniture parts are drawers, sliding doors, revolving doors or pivot doors, flaps, extendables, or other movable parts which are moved or pivoted out of the stationary furniture piece for a certain purpose.
The drive arrangement is generally attached to the stationary furniture part. But it is also possible to attach the drive arrangement to the movable furniture part for moving the movable part away from the stationary part.
The shape memory elements which provide for a linear movement and which are used for example for the opening of drawers may be arranged in the furniture body on the side, behind, above or below the drawer. Their longitudinal orientation may be aligned with, transverse or inclined to, the direction of movement of the drawer. The shape memory elements may be arranged along the back wall along several drawers vertically or diagonally with respect to the furniture body.
The shape memory element in the form as a central drive element is subjected to high stresses if the operating stroke is inhibited or blocked during operation. In order to prevent an overload of the shape memory element, it is supported on the stationary furniture part or the opening and closing mechanisms of the movable furniture part by way of a coupling which opens depending on the force applied thereto.
This coupling may be a force-locking coupling in the form of a magnetic clutch. Herein the two parts being connected may be coupled by permanent magnetic or electromagnetic forces. Also a form-locking coupling in the form of a symmetric or asymmetric engagement lock may be used which engages in a force-locking and form-locking manner.
Further features of the invention will become apparent from the following description of a particular embodiment thereof described below with reference to the accompanying drawings.
An individual pull wire has in the exemplary embodiment shown herein a round cross-section and for example a diameter of 0.5 mm. The pull wire cross-section may also have an oval, square, rectangular elliptical star- or V-shape or any other possible cross-sectional shape.
The housing 231 shown in
During operation, the housing 231 in closed by a cover which is mirror-reversed with respect to the housing bottom 246 and also includes a guide frame 232 and a recess 233.
The operating carriage 250 which is disposed in the guide frame 232 so as to be longitudinally movable is shown in
As shown in
The guide carriage 260 includes as part of the web 261 a front wall 262 with a dead-end bore 263. In the dead end bore 263, there is for example a magnet 32 or a magnetic plate mounted by cementing or clamping or by any other mounting means. For example, the cylindrical magnet 32 whose centerline extends parallel to the direction of movement of the guide carriage is aligned with the magnet 31 of the operating carriage 250. The centers (of gravity) of the magnet poles are disposed on the center lines of the magnets. The north pole of the one magnet 31 is disposed opposite the south pole of the other magnet 32. As shown in
The pull member 92 is supported by the guide pin 269. The guide pin 269 projects at the top and the bottom so far from the push pawl 266 that it is safely guided in the two elongated guide openings 264 of the housing 231. At the front end of the slide arm 266, there is a control pin 268 which extends parallel to the guide pin 269 and which extends through the elongated guide opening 264 and into the recesses 233 of the housing 231.
The opening lever 270 has an essentially disc-like hub 272 and a sickle-shaped curved long arm 271, see
For opening the drawer 21, the drawer is pressed with its rear wall 22 in the closing direction against the switch 8, see
Shortly before the opening lever has reached its end position as shown in
Then the operating carriage 250 and the guide carriage 260 are moved by the pull forces of the spring 24 toward the right, whereby the opening lever 270 pivots back, see
During the following extension phase of the pull wire 91, the tension spring 249 attached to the lever arm 267 results in a displacement of the push pawl 266 toward the right. As soon as the pull wire has cooled down, the control pin 268 is again disposed in front of the engagement flank 265 for re-coupling the operating carriage 250 to the pull wire 91, see
Upon closing the drawer 21, the operating mechanism is again in its original position.
Now the movement of the drawer is braked abruptly. This may occur when the opening drawer 21 abuts for example an external object or is stopped by an operator. This causes in the pull wire 91, which becomes shorter as a result of the earlier energization, to an excessive tension force. As soon as this tension force reaches the force required for opening the coupling 30, the magnets 31, 32 are disconnected. Then the guide carriage 260 moves to the left further tensioning the spring 249 whereas the guide carriage 250, driven by the tension spring 241, moves rapidly to the right while pivoting the opening lever 270 rapidly back, see
As the pull wire 91 cools down and becomes longer, it is pulled by the tension spring 249 via the push pawl 266 to the right. Herein, the control pin 268 carries the guide carriage 260 along by via the elongated guide opening 264. When the pull wire 91 has cooled down the magnets 31 and 32 come again in contact with each other. The coupling is again closed. Now the arrangement is ready for another drawer opening procedure.
It is possible to prevent a premature energization of the pull wire 91 by monitoring for example the end position of the guide carriage 260 as it is shown in
In accordance with
Upon engagement of the force-locking magnetic coupling 130, see
The hooks of the engagement pin 331 have an engagement flank 333 and a locking flank 332. With the engagement coupling 330 coupled the locking flank 332, which projects at an angle of 45° abuts the bore 337 walls at a 45° face angle. The engagement flank 333 extends at an angle of 15° with respect to the engagement direction 339. This small angle is intended to keep the coupling resistance small whereas the 45° angle of the locking flank 322 provides for a relatively large holding force.
The couplings 30, 130 and 330 are arranged in the exemplary embodiments between the pull wire 91 and the operating carriage 250. However, the couplings 30, 130 and 330 may also be positioned between the pull wire 91 and the body-side support point 237. It is also possible to integrate the couplings 30, 130, 330 into the pull wire 91 if they include also a guide system and spring element for the closing movement.
For opening the drawer 21, the switch 8 actuated by a closing movement may be replaced by an operating element which is arranged on the body 11, the drawer 21 or another suitable location. Also, a wireless operating arrangement is possible.
REFERENCE NUMERALS
Claims
1. An operating mechanism for moving a movable furniture part (21) relative to a stationary furniture part (11), comprising: a drive arrangement (230) including a shape memory element (91) for initiating movement of the movable furniture part (21), said drive arrangement (230) being fixed to one of the furniture parts (11, 21) and abutting the other furniture part (21, 11) via a coupling element (270) and including the shape memory element (91) as drive element arranged between the coupling element (270) and a stationary support point (237), the shape memory element (91) being connected to at least one of the coupling element (270) and the stationary support point (237) via at least one of a force-locking coupling structure and a form-locking coupling structure (30, 130, 330).
2. The operating mechanism according to claim 1, wherein the shape memory element (91) is one which becomes shorter upon heating and, reversibly, becomes longer upon cooling.
3. The operating mechanism according to claim 1, wherein the shape memory element (91) is heatable by electric energization.
4. The operating mechanism according to claim 1, wherein the shape memory element (91) consists of at least one wire or a bundle of wires of any desired cross-sectional shape.
5. The operating mechanism according to claim 1, wherein the coupling element (270) is connected to the shape memory element (91) via a joined structure of an operating carriage (250) and a guide carriage (260) wherein the two carriages (250, 260) are joined by one of a magnetic coupling (30, 130) and a mechanical engagement coupling (330).
6. The operating mechanism according to claim 1, wherein the coupling structure (30, 130) is a magnetic coupling including a first coupling element (28, 131) and a second coupling element (32, 132) and at least one of the coupling elements (31, 131, 32, 132) is one of a permanent magnet and an electromagnet.
7. The operating mechanism according to claim 6, wherein means are provided for damping the coupling movement of the magnetic coupling (30, 130) by way of one of a rubber-elastic and a pneumatic damper (36, 236, 131).
8. The operating mechanism according to claim 5, wherein the engagement coupling (330) includes an engagement lock structure (331) comprising an engagement pin (331) and a blocking structure (336) with a limited retaining force.
9. The operating mechanism according to claim 8, wherein the engagement pin (331) comprises at least a double-flank hook which has a locking flank (339) and an installation flank (333), with the locking flank (339) being oriented in locking direction and having a locking flank (332) that is arranged, with respect to the locking direction, at a greater angle than the installation flank (333).
10. The operating mechanism according to claim 1, wherein the drive arrangement (230) is fixed to one of the furniture parts (11, 21) and abuts the other furniture part (12, 11) via the coupling element (270) only at times.
Type: Application
Filed: Jan 3, 2011
Publication Date: Jun 16, 2011
Inventors: Günther Zimmer (Rheinau), Martin Zimmer (Rheinau)
Application Number: 12/930,321