Electromotive Linear Drive

Abstract

The invention relates to an electromotive linear drive ( 10 ) for adjustable components of furniture. The electromotive linear drive is constructed in such a manner that the full function is guaranteed, for the smallest possible dimensions and for the smallest possible number of components. According to the invention, the output element of the rotation speed reduction gear ( 27, 28 ), is a toothed wheel or worm wheel ( 28 ) provided with a centrically inner threaded bore. The actuator is an adjusting spindle ( 29 ) which is in contact with the toothed wheel or the worm wheel ( 28 ) and prevented form rotating and can only move in the spindle's longitudinal direction. The housing ( 11 ) has recesses which are covered by a closing element ( 16 ), with an axis of the furniture arranged in the recesses. The inventive electromotive linear drive ( 10 ) is particularly suitable for the adjustable elements of a slatted frame.

1 . An electromotive linear drive for an adjustable component of an item of furniture, comprising: 
 a housing having spaced-apart housing walls with aligned openings for receiving an axle of a movable furniture component,    a closing element which covers the openings and is secured on edges of the housing walls for securing the axle,    a drive motor and a rotation speed reduction gear which is coupled to the drive motor and has at least one driven element implemented as a toothed wheel or a worm wheel having a central bore with an interior thread, and    at least one linearly movable actuator which is implemented as an adjusting spindle in engagement with the toothed wheel or the worm wheel and secured against rotation, wherein the actuator is driven by the driven element so as to be moveable only along a longitudinal direction and operatively connected with an articulated lever attached to the axle for converting the linear motion of the actuator to a rotary motion of the axle.    
   
   
       2 . The electromotive linear drive of  claim 1 , further comprising guides disposed in the housing walls for guiding the closing element for movement in the longitudinal direction of the axle, wherein the closing element is formfittingly connected in an end position with upper edges of the housing walls.  
   
   
       3 . The electromotive linear drive of  claim 2 , wherein each housing wall has at least two undercut grooves which are aligned with one another.  
   
   
       4 . The electromotive linear drive of  claim 2 , wherein each housing wall has two respective grooves disposed on both sides of the aligned openings, and wherein at least one of the grooves facing an aligned opening is undercut.  
   
   
       5 . The electromotive linear drive of  claim 3 , wherein the closing element includes safety ribs which engage with the grooves in the housing walls.  
   
   
       6 . The electromotive linear drive of  claim 5 , wherein the safety ribs extend from one longitudinal side to an opposite longitudinal side of the closing element.  
   
   
       7 . The electromotive linear drive of  claim 1 , wherein the closing element comprises reinforcing ribs disposed on a free outer side or a free inner side of the closing element and extending in a longitudinal direction of the closing element.  
   
   
       8 . The electromotive linear drive of  claim 1 , wherein the closing element includes integrally formed or attached sections, which engage for force transmission or formfittingly in the housing or on the housing.  
   
   
       9 . The electromotive linear drive of  claim 1 , wherein the housing is made of plastic and has two housing halves with contacting surfaces, wherein the contacting surfaces of the housing halves are oriented transversely to a rotary shaft of the drive motor.  
   
   
       10 . The electromotive linear drive of  claim 9 , wherein the contacting surfaces of the housing halves are profiled, toothed or have a complementary shape, and wherein the contacting surfaces mesh with one another.  
   
   
       11 . The electromotive linear drive of  claim 9 , wherein the housing halves include ring-shaped pegs, ribs or openings which are arranged concentrically with respect to one another and extend around fastening screws such that the housing halves nest with each other when the screws are tightened.  
   
   
       12 . The electromotive linear drive according of  claim 1 , further comprising a bead forming a stop edge disposed inside of the housing for supporting the gear or a component of the gear against displacement caused by gravity during return travel of the connected furniture component.  
   
   
       13 . The electromotive linear drive of  claim 1 , wherein the housing halves are reinforced with fibers to reduce a thickness of the housing walls.  
   
   
       14 . The electromotive linear drive of  claim 9 , wherein the housing comprises a cover made of a rigid material or an elastic material and located on a side of the housing facing away from the articulated lever, with the adjusting spindle positioned in the cover in a retracted position.  
   
   
       15 . The electromotive linear drive of  claim 14 , wherein the cover is snapped onto the housing ( 11 ) or screwed together with the housing, or wherein one of the housing halves together with the cover form a single molded piece.  
   
   
       16 . The electromotive linear drive of  claim 1 , wherein the housing includes an opening or a recess on a side facing the drive motor for providing a torque support.  
   
   
       17 . The electromotive linear drive of  claim 16 , wherein a width of the opening of the torque support can be changed by way of a component or a closing mechanism, or wherein the opening can be covered by an additional closing element.  
   
   
       18 . The electromotive linear drive of  claim 9 , wherein the housing halves comprise are provided intersecting reinforcing ribs.  
   
   
       19 . The electromotive linear drive of  claim 18 , wherein the housing halves have a smooth outer surface and wherein the intersecting reinforcing ribs are arranged inside the housing halves.  
   
   
       20 . The electromotive linear drive of  claim 18 , wherein the reinforcing ribs bordering the aligned openings extend concentrically or approximately concentrically with respect to the aligned openings.  
   
   
       21 . The electromotive linear drive of  claim 18 , wherein a travel range of the articulated lever is not obstructed by reinforcing ribs.  
   
   
       22 . The electromotive linear drive of  claim 1 , wherein the spindle is made of steel or plastic.  
   
   
       23 . The electromotive linear drive of  claim 22 , further comprising a pressure block affixed on an end region of the spindle facing the articulated lever.  
   
   
       24 . The electromotive linear drive of  claim 23 , wherein the pressure block is made of plastic and comprises a metallic reinforcing insert.  
   
   
       25 . The electromotive linear drive of  claim 23 , wherein the pressure block is made of steel, and further comprising a plastic guide placed on an exterior surface of the steel pressure block, with the plastic guide comprising two plastic caps disposed on a side of the pressure block.  
   
   
       26 . The electromotive linear drive of  claim 23 , wherein the pressure block and the spindle are joined by a force-transmitting connection, a formfitting connection or a material connection, or form a molded part.  
   
   
       27 . The electromotive linear drive of  claim 24 , wherein the metallic reinforcing insert is arranged inside the plastic block or is applied to the pressure block at least on a side facing the articulated lever.  
   
   
       28 . The electromotive linear drive of  claim 23  wherein, the pressure block, the metallic reinforcing insert of the plastic pressure block, a plate attached to a steel spindle, or an end face of the spindle itself forms the contact surface to the articulated lever, said contact surface being arranged perpendicular to the longitudinal center axis of the spindle or at an angle with an offset relative to the vertical.  
   
   
       29 . The electromotive linear drive of  claim 1 , wherein the articulated lever is angled and fabricated as a punched steel part or a cast steel part with parallel side edges.  
   
   
       30 . The electromotive linear drive of  claim 23 , wherein a surface of the articulated lever facing the pressure block is shaped as an arc or a semicircle.  
   
   
       31 . The electromotive linear drive of  claim 1 , and further comprising a roller bearing supporting the worm wheel and a gear angle implemented at a machined part.  
   
   
       32 . The electromotive linear drive of  claim 31 , wherein the gear angle includes a sleeve for receiving the roller bearing and a mounting flange for attachment to the housing of the drive motor.  
   
   
       33 . The electromotive linear drive of  claim 24 , wherein the gear angle is made of plastic and reinforced with fibers.  
   
   
       34 . The electromotive linear drive of  claim 31 , wherein, the worm wheel is formed in two parts and comprises an outer rim with a tooth pattern and a support sleeve, wherein the support sleeve is provided with the interior thread and with an outer bearing seat for the roller bearing.  
   
   
       35 . The electromotive linear drive to of  claim 34 , and further comprising ribs and grooves which formfittingly connect the outer rim with the support sleeve.  
   
   
       36 . The electromotive linear drive of  claim 34 , wherein the worm wheel together with the bearing seat and the interior thread are formed as a one-piece molded plastic part.  
   
   
       37 . The electromotive linear drive of  claim 1 , wherein the linear drive is formed as a non-self-locking drive, and wherein the linear drive further comprises a brake element effective in a travel direction of the spindle for stopping a load when the drive motor is switched off.  
   
   
       38 . The electromotive linear drive of  claim 37 , and further comprising a gear angle with a sleeve, wherein the brake element is implemented as a spring brake element having several turns and arranged in an annular gap between the sleeve and a bearing seat, with one end of a turn being secured in the sleeve of the gear angle.  
   
   
       39 . The electromotive linear drive of  claim 1 , wherein the spindle is made of steel, with a free end face facing away from the worm wheel operating on a slider element guided in the housing.  
   
   
       40 . The electromotive linear drive of  claim 39 , wherein the free end face of the spindle that faces away from the worm wheel is perpendicular to the longitudinal center axis of the spindle or is inclined with respect to the vertical and is formed as a pressure block for forming contact faces to the articulated lever.  
   
   
       41 . The electromotive linear drive of  claim 9 , wherein the housing has two housing halves with interior mounting ribs oriented transversely to the longitudinal center axis of the spindle, and further including a gear angle with a sleeve, with the mounting ribs supporting end faces of the sleeve of the gear angle.  
   
   
       42 . The electromotive linear drive of  claim 1 , further comprising a pressure element placed on the spindle, wherein the pressure element has steps on a side facing the articulated lever, thereby providing a lateral two-dimensional contact between the articulated lever and the pressure element.  
   
   
       43 . The electromotive linear drive of  claim 31 , wherein the electromotive linear drive unit with the flanged-on gear angle and the worm wheel mounted therein and the roller bearing form a mounting unit, allowing storage of the unit without use of mechanical elements.  
   
   
       44 . The electromotive linear drive of  claim 31 , wherein at least a region located between the gear angle and the housing is filled with a sound-absorbing material.  
   
   
       45 . The electromotive linear drive of  claim 44 , wherein the sound-absorbing material is formed as a rubber element, or as a rubber element that is extrusion-molded on a housing half or on the gear angle.  
   
   
       46 . The electromotive linear drive of  claim 31 , wherein a lower side of the housing, which faces away from the aligned openings, includes two transport elements adapted for attachment to the housing formfittingly or for force transmission.  
   
   
       47 . The electromotive linear drive of  claim 46 , wherein a lower side of the transport elements facing away from the housing wall includes two aligned semicircular tapers.  
   
   
       48 . The electromotive linear drive of  claim 47 , wherein the housing has two housing halves and the semicircular tapers are formed on the housing halves as a single piece.  
   
   
       49 . The electromotive linear drive of  claim 1 , wherein the housing further comprises a terminal for a power cable and a control board arranged inside the housing, such that an interior space of the housing is free from cables.  
   
   
       50 . The electromotive linear drive of  claim 49 , wherein the housing further comprises a control board arranged inside the housing or in a shaped extension of the housing with an inserted electrical component for controlling the electric motor, or a printed circuit board arranged inside the housing as a current distribution board, which separates and transmits electrical signals for control and power supply.  
   
   
       51 . The electromotive linear drive according of  claim 1 , wherein the drive motor and a terminal for supplying electric power are covered by a common cover.  
   
   
       52 . The electromotive linear drive of  claim 1 , and further comprising a limit switch for limiting an end position of the spindle.  
   
   
       53 . The electromotive linear drive of  claim 1 , wherein the housing further comprises ribs, pegs or rails for formfitting attachment of a control housing or a power distribution unit.  
   
   
       54 . The electromotive linear drive of  claim 1 , wherein the housing comprises ribs or recesses for formfitting attachment of a power cable or a power distribution or a plug connector for transmitting electric power.  
   
   
       55 . The electromotive linear drive of  claim 1 , wherein an outer surface of the housing includes ribs for attachment of a manual control unit.  
   
   
       56 . The electromotive linear drive of  claim 1 , wherein the housing includes pockets or webs for receiving batteries for supplying emergency power.  
   
   
       57 . The electromotive linear drive of  claim 1 , wherein the housing includes pockets or webs for receiving power supply units, control units and mounting units, such as transformers, DC power supplies, manual switches, and closing elements, wherein the units are detachable from the linear drive after transport.  
   
   
       58 . The electromotive linear drive of  claim 1 , wherein the housing includes ribs or pegs for securing a cable for stress relief, and arcuate projections or recesses for supporting a cable with a minimum allowable bending radius as an anti-kink protection for the cable.  
   
   
       59 . The electromotive linear drive according of  claim 1 , wherein the housing includes ribs or pegs, which connect at least one electrical terminal with the housing for force transmission or formfittingly, or a safety element attached to the pegs or ribs for securing a motor terminal on the housing.  
   
   
       60 . The electromotive linear drive of  claim 50 , wherein the at least one electrical terminal is a motor terminal.  
   
   
       61 . The electromotive linear drive of  claim 13 , wherein the fibers are glass fibers.  
   
   
       62 . The electromotive linear drive of  claim 33 , wherein the fibers are glass fibers.