DE202008013237U1 - Adjusting drive for an adjustable part of a piece of furniture - Google Patents

Abstract

Adjusting drive for an adjustable part of a piece of furniture, in particular for the height and / or lying surface adjustment of a bed such. B. a hospital or nursing bed,
A housing (12),
- One in the housing (12) arranged gear (20) having a rotatable drive element (26) and an engageable with an adjustable part of a furniture operatively driven element (32), and
A motor (16) having a drive shaft (18) for rotationally driving the drive element (26),
marked by
A position sensor (44) for determining the position of the output element (32),
- Wherein the drive element (26) between two substantially opposite gears (28, 40) is arranged, with which the drive element (26) is in mechanical contact, and
- Wherein the first gear (28) with the output element (32) and the second gear (40) with the encoder (44) is coupled.

Description

The The invention relates to an adjusting drive for an adjustable Part of a piece of furniture, in particular for the height and / or lying surface adjustment of a bed such as a hospital or nursing bed.

Electrically adjustable furniture such as height-adjustable tables, armchairs, sofas and chairs with Sitzflächen- and / or backrest adjustment or beds, especially hospital or nursing beds with height and / or reclining require as compact adjustment drives that are low maintenance, easy to install and reliable or work should. Examples of such adjustment can be found in DE 296 96 367 U1 . DE 20 2007 006 469 U1 . DE 20 2007 005 308 U1 . EP 1 400 726 A1 . EP 0 662 573 B1 and DE 103 29 097 A1 ,

These known adjusting drives have a housing and a in arranged on the housing gearbox. This drive As a rule, includes a rotatable, motor-driven drive element and an output element with the adjustable part of a piece of furniture can be brought into operative connection. The drive element is usually driven by an electric motor, with its drive shaft the Drive element is rotatably connected.

For the automatic control of a piece of furniture with several Actuators, as at a hospital or Care bed with height and / or lying surface adjustment the case is, it is under the aspect of minimizing the wiring advantageous if the individual adjustment drives are connected to a bus are, for example, controlled by a central control unit becomes. In addition to the adjustment drives, such furniture has more advantageous But also position or Weggeber on who the instantaneous adjustment of an adjusted part of the furniture Show.

These Position encoders are usually also connected to the bus. each The unit connected to the bus requires a bus communication interface with appropriate electronics, which is expensive and in particular also complicates the bus protocol and the bus communication.

task The invention is therefore an adjustment for a to create an adjustable part of a piece of furniture in which the Feedback of the position of adjustable with the adjustment Partly realized in a simple way.

• – einem Gehäuse,
• – einem in dem Gehäuse angeordneten Getriebe, das ein drehbares Antriebselement sowie ein mit einem verstellbaren Teil eines Möbels in Wirkverbindung bringbares Abtriebselement aufweist,
• – einem Motor mit einer Antriebswelle zum drehenden Antreiben des Antriebselements und
• – einem Weggeber zur Ermittlung der Stellung des Abtriebselements,
• – wobei das Antriebselements zwischen zwei einander im wesentlichen gegenüberliegenden Zahnrädern angeordnet ist, mit denen das Antriebselement mechanisch in Kontakt steht, und
• – wobei das erste Zahnrad mit dem Abtriebselement und das zweite Zahnrad mit dem Weggeber gekoppelt ist (allgemein: in Wirkverbindung steht).

To solve this problem, the invention proposes an adjusting drive for an adjustable part of a piece of furniture, in particular for height and / or lying surface adjustment of a bed such as a hospital or nursing bed, wherein the adjustment is provided with

• A housing,
• A gear arranged in the housing, which has a rotatable drive element and an output element which can be brought into operative connection with an adjustable part of a piece of furniture,
• A motor having a drive shaft for rotationally driving the drive element and
• A position sensor for determining the position of the output element,
• - Wherein the drive element is arranged between two substantially opposite gears, with which the drive element is mechanically in contact, and
• - Wherein the first gear is coupled to the output element and the second gear to the encoder (in general: is in operative connection).

at the adjusting drive according to the invention, the features described above in connection with the prior art has, the drive element between two is substantially opposite Gear wheels arranged. The first of these two gears is with the output element (directly or eg via a Gearbox indirectly). Will this first gear from the Driven drive element when the output element under load is, so acts on the drive element or the drive shaft of the motor directed away from the gear torque. To the drive element It will continue to engage with the first gear counteracted by the second gear so to speak and thus engaged held with the first gear. The second gear is therefore the Recording of the previously described, occurring under drive under load and torques acting on the drive element.

According to the invention Now this second gear used to operate a Weggeber, the is coupled to the second gear (directly or indirectly). Of the Position sensor serves to determine the (rotational) position of the output element. In this way, therefore, the second gear can be used twice, which leads to a compact construction of the adjustment drive. If such an adjustment drive is connected to a bus, Thus, both the adjustment drive via a single bus interface be controlled, as well as the adjustment of the current position of the output element are reported. From this information can then in a parent unit to the adjustment position be closed of the adjustable part of the furniture.

The displacement sensor is expediently a potentiometer and in particular a rotary potentiometer. Such way Sensors are robust and work reliably. As an alternative to such resistively operating encoders, other electrically, capacitively, inductively, optically or magnetically operating displacement sensors or sensors come into question. The displacement sensor can be either a relative or an absolute position encoder. The displacement sensor can also be designed as a decoder.

Around the adjustable part of a piece of furniture with the aid of the invention Adjusting drive to move in the entire adjustment, is As a rule, be required that the output element several times turns around its own axis. This multiple rotation of the output element is suitably reduced to less than one revolution or, more generally, on a comparatively small scale Path of the Weggebers shown. This is useful Way a reduction gear stage of the adjustment, the also housed in the housing. About these Reduction gear is then the second gear with a Encoder element of the encoder coupled. In the case of a potentiometer Thus, the sliding contact becomes either linear from the second gearwheel or rotatory moves.

As already stated above, which is driven by the engine Drive element between two gears. Here it is Drive element expediently as a screw educated. Alternatively, the drive element itself as Gear be configured.

in the Case of the formation of the drive element as a screw, have the both gears, for example, a helical toothing on, which are engaged with the snail. additionally but the two gears can also have more Have teeth over which they directly communicate with each other comb. This leads to an increased Resistance of the coupling of worm and first gear, when the drive accidentally "drives on block", by the snail through the gears opposite Resistance moment is increased.

For the purpose of further increase the compactness of the construction of the invention Adjusting it is expedient if a Bus communication unit and the encoder (possibly with further electrical or electronic components) on one common circuit board are arranged, which in turn protected housed in the housing.

at the output element of the transmission of the adjustment is expediently a gear (for example for driving a toothed belt) or a spindle, which is equipped with a spindle nut meshes and represents a linearly movable output element. It is also conceivable, the output element optionally with a gear or rotatably connect a spindle. This enlarges the Application of the adjustment drive.

at a adjustable by an adjustment part of a piece of furniture There is a risk that load moments, with the engine off act on the output element, to a movement of the adjustable Part of the furniture lead. This is usually undesirable. So should, for example, a tilted Upper body part of the bed surface of a bed not self-adjusting (back) when in bed a person lies. Especially for hospital and nursing beds such a case should not occur.

To remedy this problem, the known adjustment drives mentioned at the beginning have load torque locks which prevent the output element from being moved by externally acting moments when the motor is switched off. Here, it is generally known to use so-called claw brakes with coil springs, which are arranged radially outwardly biased arranged in a brake drum. Such a brake, which is automatically activated when acting on the driven element in the directions of movement of the output element acting torques, can be integrated in a simple manner in the adjustment according to the invention. For this purpose, the adjusting expediently has a 2-part shaft between the first gear and the driven element. This two-part shaft is provided with a gear shaft coupled to the gear and with an output member shaft coupled to the output member. Both shaft parts engage in each other via axially projecting jaws, so that upon rotation of the first gear or the gear shaft, the output element shaft is entrained. But now that acting on the output element shaft from the side of the output element torque does not lead to a rotation of the output element shaft (which would cause an unintentional adjustment of the driven by the adjustment part of the furniture), in the brake, a brake drum is provided with arranged in this coil spring, both of which are arranged around the two-part shaft in the area of the intermeshing claws. The Schraubenbremsfeder has at its two ends radially inwardly projecting driver arms which protrude between two circumferentially consecutive claws of the two shaft parts. This arrangement is now made such that the entrainment of one of the driver arms by a claw of the gear shaft (depending on the direction of rotation of the gear shaft whose claw takes either one or the other Mitnehmerarm the screw brake spring with) to a radial sammenziehen the screw brake spring results, with the result that the radially acting pressure force with which the screw brake spring from the inside of the brake drum, decreases and the Schraubenbremsfeder can rotate within the brake drum (generally under the brake drum). Conversely, if one of the driving arms of the screw brake spring is taken by the or one of the claws of the driven element shaft, acting on the screw brake spring this further aufstellendes, which means that the screw spring applies with increasing force from the inside to the brake drum and thus the Braking effect is generated. The claw brake described here is known per se. Their advantage is their functional reliability and compact design, which is why they can be combined with advantage with the adjusting drive according to the invention.

In Advantageous development of the invention is further provided that the housing is formed in three parts and a first Housing part, on which the engine under extension of his Drive shaft fixed in the first housing part inside is, connectable to the first housing part, to two opposite sides open second housing part and a cover closing the second housing part having. The lid, the first and the second housing part are interconnected by means of connecting elements, which themselves between the lid and the first housing part and through extend the second housing part therethrough.

The Invention will be described below with reference to an embodiment of the invention and with reference to the drawings explained. In detail, they show:

1 a side view of an embodiment of the adjusting drive with indicated internal structure of the transmission and the encoder,

2 a view of the adjusting drive along the line II-II with removed upper housing part, wherein in 2 as a driven element a gear is shown

3 an alternative embodiment of the adjustment in view along the line II-II of 1 , where in 3 as output element a spindle for a spindle drive is shown,

4 an enlarged view of 1 with in the range of IV the 1 broken housing to clarify the gear stage for the encoder and the arrangement of the encoder on a board with bus communication and other electronics,

5 a sectional view taken along the line IV-IV in the 2 to clarify the structure of the claw brake,

6 to 8th respectively. 9 to 11 Sectional views along the line VI to XV of 5 to clarify the release of the dog brake, when the motor-side driven gear for driving the driven element is moved in one of the two opposite directions, and

12 and 13 respectively. 14 and 15 Sectional views along the line VI to XV to illustrate the automatic braking action of the dog brake for the cases that the output element in one of its two directions of movement on the output side, that is moved from the outside, for example, by load moments acting on a adjustable by the adjustment part of a piece of furniture , can be done.

In the 1 to 5 is the structural design of an embodiment of erfindungemäßen adjustment 10 shown. The adjustment drive 10 has a three-part housing in this embodiment 12 on, with the housing 14 an electric motor 16 firmly connected, the electric motor 16 has a drive shaft 18 on, which is in the case 12 extends into it.

In the case 12 is a transmission 20 arranged that as a snail 24 trained, rotationally fixed with the motor shaft 18 connected drive element and a first gear engaged with this 28 having.

The first gear 28 is about a wave 30 with an output element 32 coupled. At the output element 32 this is the case in the exemplary embodiment 2 around a gear 34 for example, for driving a toothed belt while in 3 as output element 32 a spindle 36 is shown. Both output elements can be advantageously with the shaft 30 rotatably connect. This is served in the 2 and 3 indicated coupling, which is formed for example as a polygonal pin with complementary square recess. But it is also possible that the gear 34 or the spindle 36 permanent and therefore not removable with the shaft 30 connected is.

Next to the first gear 28 of the transmission 20 shows the case 12 a second gear 40 on, also from the drive element 26 (Slug 24 ) is driven in rotation (see the first teeth 22 ). Both gears each have a toothing 41 on which they comb directly with each other. The second gear 40 is part a (reduction) gear stage 42 for actuating a displacement sensor 44 with encoder element 45 ,

The second gear 40 lies, based on the position of the drive element 26 , the first gear 28 across from. In other words, so are the drive element 26 directly between the two gears 28 and 40 , The second gear 40 supports the drive element 26 off, if on this more to the drive shaft 18 and from the first gear 28 directed torques or torque components act, as is the case in particular when the adjustment operates under load. In that regard, so supports the second gear 40 the drive shaft 18 or the drive element 26 (Snail) from.

In addition, the second gear is used 40 but also the operation of the encoder 44 , Here is the second gear 40 Part of the gear stage 42 and is on a common wave with a snail 46 arranged, in turn, a gear 48 drives on a common shaft with a smaller diameter gear 50 is arranged, which in turn is another gear 52 drives, its shaft 54 finally the giver 45 actuated. The Weggeber 44 is in this embodiment as a rotary potentiometer 56 educated.

The rotary potentiometer 56 is on a circuit board 58 arranged, inter alia, a bus communication unit 60 and further electrical or electronic components. The electrical supply and control of the adjustment drive 10 via a plug 62 whose connections are accessible from outside the housing. The board 58 is also about another plug 64 electrically with the engine 16 connected.

The bus communication unit makes it possible to adjust the adjustment drive 10 to control via a bus line. At this bus line then several adjusting drives 10 be connected. In this way, for example, all installed in a furniture adjusting drives can be controlled via a single bus communication line. This reduces the wiring effort and thereby improves the quality by reducing the risk of failure by reducing the number of connections in the wiring harness. Furthermore, the use of bus communication units and the connection of the adjustment drives to a bus allows a reduction in the number of connectors, variety of connectors and connector sizes, since the installed adjustment drives are connected consistently via standard plug connections. Finally, the adjustment itself is standardized or it can be used on standardized adjusting drives. The diagnostic capability of all adjusting drives can also be implemented in a simple manner, in that all the adjusting drives and other components connected to the bus can be tested via a diagnostic tester. This simplifies the search for errors, which in turn speeds up the process of fixing the errors.

Finally, it follows from the 1 and 4 also the three-part construction of the housing 12 , This has a first housing part 66 on, on which the case 14 of the motor 16 is attached. To the first housing part 66 closes a second housing part 68 at. Between the two housing parts are the gears 28 . 40 as well as the first gear 28 with the output element 32 connecting shaft 30 stored. Also parts of the gear stage 42 for the rotary potentiometer 56 are between the two housing parts 66 . 68 stored.

On the first housing part 66 opposite side of the second housing part 68 there is a lid 70 that's the towering pens 72 of the second housing part 68 held board 58 covered. The three housing components are through continuous screws 74 firmly connected to each other and liquid or splash water tight.

Finally, it is in the case 12 the drive unit 10 also a brake 76 , This brake 76 serves as a load torque lock and prevents the engine from being switched off 16 the output element 32 can turn, if on the output element 32 Torques act, which can occur for example due to external loads. The brake 76 will be over the shaft 30 actuated. The transmission of the rotational movement of the first gear 28 on the output element 32 acting wave 30 is formed in two parts and has a housing 12 at 78 rotatably mounted output element shaft 80 and a gear shaft 82 on, with the first gear 28 rotatable on the output member shaft in this embodiment 80 is stored. The output element shaft 80 and the gear shaft 82 are each with two opposing, axially projecting jaws 84 . 86 provided, which mesh, resulting in rotation of the first gear 28 also the output element shaft 80 rotates. The mesh of the claws 84 and 86 is in the 6 to 15 shown.

To the claws 84 and 86 around a coil spring extends 88 with multiple windings biased radially outward in a brake drum 90 is arranged and on the inner peripheral side 92 with force. The screw brake spring 88 has at its ends in each case a radially inwardly directed driving arm 94 . 96 on. The distance between these two driving arms 94 . 96 in the circumferential direction of the screw brake spring 88 when viewed in the axial direction (see, for example 6 ) is chosen such that one of the two claws 84 the gear shaft 82 So one of the two drive-side claws 84 axially between these Mitnehmerarmen 94 . 96 extends through. In other words, so the two driver arms protrude 94 . 96 on both sides of the said drive-side claw 84 in the spaces between this claw 84 and the respective adjacent output-side jaws 86 , as for example in 6 is shown.

The brake drum 90 is rotatable in a receptacle 98 of the first housing part 66 added. For this purpose, the brake drum 90 for example, a hexagon outer contour. The brake drum 90 is suitably made of a metallic material, as with the screw brake spring 88 the case is.

Based on 6 to 11 is briefly explained below, that the Schraubenbremsfeder 88 in the brake drum 90 along with the first gear 28 or the drive-side claws 84 moved when the first gear 28 from the engine 16 is driven. It does not matter in which direction the first gear 28 rotates.

6 shows the starting situation, out of which now the drive-side claws 84 in the direction of the arrow 100 rotate. The between the two driving arms 94 and 96 arranged drive-side claw 84 comes in contact with the driving arm 96 the screw brake spring 88 (please refer 7 ) what with further movement of the claw 84 to a constriction of the screw brake spring 88 leads, so that this rotates and in consequence the drive-side claws 84 in contact with the driven-side jaws 86 arrive, so that the output element 32 is turned. The situation with rotation of the first gear 28 in the opposite direction (see directional arrow 102 ) is in the 9 to 11 shown.

Now works with the engine off 16 on the output element 32 a torque, so must be a rotation of the output element 32 be prevented. In this case, so speaks the brake 76 regardless of the direction in which the torque is applied to the driven element 32 acts.

The 12 and 13 show the case that the output element 32 in the direction of the arrow 104 is twisted. This twist leads after a short time already to one of the two output-side jaws 86 in contact with one of the two driving arms 94 . 96 arrives. This situation is in 13 shown in the one of the two output-side claws 86 in contact with the driving arm 96 the screw brake spring 88 arrives. Upon further rotation of the claw 86 pushes it over the Mitnehmerarm 96 the screw brake spring 88 increasingly against the inner circumference side 92 the brake drum 90 what a twist of the coil spring 88 inside the brake drum 90 effectively prevented. So that's the output element 32 braked. The same situation arises when, as in the 14 and 15 shown the output element 32 in the other direction (see directional arrow 106 ) is twisted. Here then again one of the two output-side jaws 86 with the other driving arm 96 the screw brake spring 88 in contact.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 29696367 U1 [0002]
• - DE 202007006469 U1 [0002]
• - DE 202007005308 U1 [0002]
• EP 1400726 A1 [0002]
• EP 0662573 B1 [0002]
• - DE 10329097 A1 [0002]

Claims (11)

Adjusting drive for an adjustable part of a piece of furniture, in particular for the height and / or lying surface adjustment of a bed such. B. a hospital or nursing bed, - a housing ( 12 ), - one in the housing ( 12 ) arranged gear ( 20 ), which is a rotatable drive element ( 26 ) as well as an output element which can be brought into operative connection with an adjustable part of a piece of furniture ( 32 ), and - an engine ( 16 ) with a drive shaft ( 18 ) for rotationally driving the drive element ( 26 ), characterized by - a displacement sensor ( 44 ) for determining the position of the output element ( 32 ), - wherein the drive element ( 26 ) between two substantially opposite gears ( 28 . 40 ) is arranged, with which the drive element ( 26 ) is mechanically in contact, and - wherein the first gear ( 28 ) with the output element ( 32 ) and the second gear ( 40 ) with the encoder ( 44 ) is coupled. Adjusting drive according to claim 1, characterized in that the displacement sensor ( 44 ) a movable encoder element ( 45 ) and that the second gear ( 40 ) Part of a reduction gear stage ( 42 ) for moving the donor element ( 45 ) of the Weggebers ( 44 ). Adjusting drive according to claim 1 or 2, characterized in that the displacement sensor ( 44 ) is a relative or absolute Weggeber and in particular electrical, capacitive, inductive, resistive, optical or magnetic works. Adjusting drive according to claim 1 or 2, characterized in that the displacement sensor ( 44 ) a potentiometer ( 56 ), in particular a rotary potentiometer. Adjusting drive according to one of claims 1 to 4, characterized in that the between the two gears ( 28 . 40 ) arranged drive element ( 26 ) as a snail ( 24 ) is trained. Adjusting drive according to one of claims 1 to 5, characterized in that the gears ( 28 . 49 ) each have a first toothing ( 22 ) connected to the drive element ( 26 ), and a second gearing ( 41 ), over which the two gears ( 28 . 40 ) comb directly with each other. Adjusting drive according to one of claims 1 to 6, characterized in that in or on the housing ( 12 ) a bus communication unit ( 60 ) for controlling the engine ( 16 ) is arranged via a bus system. Adjusting drive according to one of claims 1 to 7, characterized in that in the housing ( 12 ) a board ( 58 ) is arranged with electrical / electronic components, wherein the displacement sensor ( 44 ) on the board ( 58 ) is arranged. Adjusting drive according to one of claims 1 to 8, characterized in that the housing ( 12 ) is formed in three parts and a first housing part ( 66 ), on the outside of which the engine ( 16 ) under extension of its drive shaft ( 18 ) in the first housing part ( 66 ), one with the first housing part ( 66 ) connectable, on two opposite sides open second housing part ( 68 ) and a second housing part ( 68 ) closing lid ( 70 ), wherein the lid, the first and the second housing part ( 66 . 68 ) by means of connecting elements ( 74 ) which are connected between the lid ( 70 ) and the first housing part ( 66 ) as well as through the second housing part ( 68 ) extend therethrough. Adjusting drive according to one of claims 1 to 9, characterized in that between the first gear ( 28 ) and the output element ( 32 ) a two-part wave ( 30 ) with one with the gear ( 28 ) coupled gear shaft ( 82 ) and one with the output element ( 32 ) coupled output element shaft ( 80 ) is arranged, that the two shaft parts ( 80 . 82 ) axially projecting and interlocking claws ( 84 . 86 ) for rotational entrainment of the output element shaft ( 80 ) through the gear shaft ( 82 ) and that around the claws ( 84 . 86 ) around a brake drum ( 90 ) arranged in this, from the inside against the brake drum ( 90 ) adjoining coil brake spring ( 88 ) is positioned, which at both its ends radially inwardly projecting driver arms ( 94 . 96 ), each between the claws ( 84 . 86 ) of the gear shaft ( 82 ) and the output element shaft ( 80 ) are arranged. Adjusting drive according to one of claims 1 to 10, characterized in that the output element ( 32 ) a gear ( 34 ) or a spindle ( 36 ) or a recording ( 38 ) for non-rotatably receiving a gear ( 34 ) or a spindle ( 36 ) having.