Patent Publication Number: US-2018049543-A1

Title: Arrangement for Height Adjustment Preferably for Kitchen Tables with Base Cabinets

Description:
The present invention relates to an arrangement for height-adjustment, preferably for base cabinets located on a floor, and where the upper side of the cabinets are furnished with a table top, particularly kitchen tables with base cabinets. This particularly relates to kitchen elements where a standard size of a base cabinet is: depth 50-60 cm and height 60-70 cm having varying widths from 30 cm to 120 cm, with leaps of 10 cm, and where the standard widths are 40 cm, 50 cm and 60 cm. 
     Height-adjustable work tables where the height of the table top can be adjusted to the height of different users have been known in special bur pose constructions for many years e.g. for emergency dispatch centers, which are manned around the clock. The development of sitting/standing tables was commenced towards the end of the 1980s/the beginning of the 1990s. This development was due to ergonomic reasons, so that the user could assume changing work positions. A number of different lifting columns designed as table legs have been developed for these sitting/standing tables, just as different linear actuators for these lifting columns have been developed. In some structures the linear actuator is an incorporated part of the lifting column and in other structures it is a separate unit which may be built into different lifting columns, Basically, a lifting column consists of a telescopic guide and the linear actuator, which typically consists of a spindle unit driven by a low-voltage DC-motor. To begin with the lifting columns were designed with two members, a fixed and an extendable member. However, due to increased requirements of the customers for the variable heights, lifting columns with three members were developed—one fixed and two extendable members. The development was, however, also marked by a desire for cheaper products in order to gain a foothold on the market. As an example of a typical lifting column for a work table and an actuator for a lifting column, reference is made to WO2004/100632 A1,Linak A/S. A typical example of a desk having a lifting column at each side is disclosed in EP 1079511 A1, Linak A/S. 
     For that reason the desire for height-adjustment has become more pronounced and has spread to other fields, where it has been attempted to use the same type of lifting columns for sitting/standing work tables. However, it has not always been possible to use these or it has, in terms of construction and design, proven to be difficult to fit the lifting columns to a given structure. 
     One of the fields, where it is desired to be able to perform a height-adjustment is kitchen tables, where the table top rests on a row of base cabinets. This is a relatively complicated task where it is not immediately possible to use the lifting columns intended for height-adjustable work tables. This is among other things due to the fact that a kitchen table is relatively long end heavy. It is particularly challenging in case of cooking islands, which often are twice as wide since they comprise two rows of cabinets placed back to back. As examples reference is made to U.S. Pat. No. 6,213,575 and US 2003/0227240 A1 both Maytag Corp., disclosing cooking islands constructed around, specially constructed height-adjustable frames. It should also be mentioned that JP20031591221 Yamaha Living Tec. discloses a kitchen table, where the table top can be raised from the lower frame. 
     The purpose of the invention is to provide a solution for height-adjustment of kitchen tables, where the table top rests on a row of base cabinets. It is required that the production and assembly costs are relatively inexpensive, just as the technical solution should be simple and preferably so simple that it is suitable for a do-it-yourself project, i.e. without actual preceding expertise in the field. 
     This is achieved according to the invention by constructing the arrangement for height-adjustment as a platform comprising a bottom plate on which a lifting arrangement having a supporting surface for an object is mounted. Thus, the height--adjustment is a separate element and already known elements such as base cabinets may be used, i.e. simply by placing them on top of the supporting surface of the platform. For kitchen, utility room, bath room and dressing room elements, having a basically standardized size, the size of the platforms may be adapted accordingly. For a kitchen table with base cabinets the required number of platforms can then merely be placed together, where after the base cabinets are placed on top of them. The advantage is also that the existing production machinery for manufacturing cabinet and drawer elements can remain intact, while the manufacturing of the platforms is transferred to a separate production, which may be optimized with a view thereto. 
     In the dependent claims more different embodiments for the height-adjustment arrangement have been provided. The claims  2 - 4  disclose embodiments based on spindles, which give the advantage of being reliable and long-lasting and with a solid spindle or a solid spindle combined with a hollow spindle a wide span in the adjustment height as well as a cost optimizing is achieved. 
     Claims  5 - 6  provide different solutions all based on the idea of using a. wedging for the height-adjustment. The wedge surfaces sliding against each other may be fashioned to have a low friction, e.g. by means of a surface treatment or surface coating, alternatively rolls may be used on the wedge surfaces. Again, this is a simple and uncomplicated construction. 
     Claims  6 - 7  provide solutions based on box-shaped profiles, which may be designed such that they can be located in pairs under each side of a base cabinet, alternatively at the front and rear edge. The latter solution further has the advantage that access under the cabinet from the front is prevented. 
     Claims  8  and  10  provide solutions with levers, where the solution in claim  8  may be moved by means of a known actuator. It is an obvious advantage that a linear actuator is a well-proven component which is simple and dependable. The solution in claim  10  is based on spindle technology and has the advantage that the levers may be arranged so that transversal forces eliminate each other. 
     Claim  9  provides an entirely different solution based on. a rope pull, where the rope may be a wire, band or the like. Again, a simple and functional solution, which likewise may be constructed relatively inexpensive. 
     The invention further relates to a cabinet with a bottom plate, being prepared for mounting of or which is mounted with at least one arrangement according to one of the claims  1 - 14 . This could e.g. be holes or dogs or brackets which should cooperate with the arrangement. 
     Various embodiments of the invention will be explained below with reference to the accompanying drawing, in which: 
       FIG. 1  shows a schematic view of an embodiment with a single spindle, 
       FIG. 2  shows a schematic view of the spindle in  FIG. 1 , 
       FIG. 3  shows a cross section through, a corner of an embodiment with hollow and solid spindle, 
       FIG. 4  shows a top or bottom plate in  FIG. 3  seen from above, 
       FIG. 5  shows a schematic view of an embodiment with a linear actuator shown without top plate, 
       FIG. 6  shows the embodiment in  FIG. 5  seen from the side, 
       FIG. 7  shows a section in the bottom plate, which exposes an adjusting screw, 
       FIG. 8  shows an embodiment based on box-shaped profiles and chain drive shown directly from the side and where it has been retracted to its minimum height, 
       FIG. 9  shows the same as  FIG. 8 , but extended to its full height, 
       FIG. 10  shows the same as  FIG. 8 , but seen directly from above, 
       FIG. 11  shows an embodiment based on box-shaped profiles and drive with a drive shaft and angle gear shown directly from the side, and where it has been retracted to its minimum height, 
       FIG. 12  shows the same as  FIG. 11 , but extended to its full height, 
       FIG. 13  shows the same as  FIG. 11  but seen directly from above, 
       FIG. 14  shows a principle sketch of an embodiment based on wedge elements shown in fully retracted position, 
       FIG. 15  shows the same as  FIG. 14 , but in fully extended height, 
       FIG. 16  shows the same as  FIG. 15 , but shown from the opposite end, 
       FIG. 17  shows an embodiment based on levers shown directly from the side, 
       FIG. 18  shows the same as  FIG. 14 , but seen directly from above, 
       FIG. 19  shows a schematic principle view of an embodiment based on wound bands, 
       FIG. 20  shows the same as  FIG. 19  but where the embodiment has three telescopic members, 
       FIG. 21  shows an embodiment based on a solid and a hollow spindle and also a tube with internal thread, 
       FIG. 22  shows an embodiment as in  FIG. 21  shown with chain drive, 
       FIG. 23  shows the same as  FIG. 22 , but seen directly from above, and 
       FIG. 24  shows a section of the drive motor and where the end stop switches are shown. 
    
    
     FIGS. l- 2  of the drawing shows an embodiment comprising a square box (shown transparent) with a bottom plate  1 , having a spindle  2  mounted on a thrust bearing  3  in each corner. The lower end of the spindle  2  is furnished with a toothed pulley  4 . All four spindles  2  are driven by a central motor  5  through a toothed belt  6 . The motor  5  and the transmission, here a worm gear and driving wheel for the toothed belt  6 , is mounted on a mutual plate, which can pivot about an axle pin, said plate being spring loaded with a coil spring at the end such that the toothed belt is held tight. A tube piece  7  extends over the spindles  2  and to the lower end of said tube piece a spindle nut  8  in mesh with the spindle  2  is secured. As the spindles  2  rotate synchronously due to the toothed belt drive, the four tube pieces  7  are displaced synchronously up and down depending on the direction of rotation of the motor. It is realized that the toothed belt  6  and corresponding toothed pulley  4  may be replaced by a chain and chain wheel. The spindles may naturally also be driven by a separate electric motor each. Alone the circumference of the bottom plate  1  a frame  9  is secured. Under a base cabinet mounted on top of the tube pieces  7  shut-offs may .  be secured to the sides of the frame  9 , which are visible after the final assembly, said shut-offs sliding on the outside of the base plate frame  9 , such that the bottom plate is covered. The upper side of the four tube pieces  7  constitutes the supporting surface. At the corners of the frame  9  guides for the tube pieces  7  on the spindle nuts may be arranged. 
       FIGS. 3-4  of the drawing show an embodiment with a larger lifting height comprising an identical bottom and top plate  10 , 11 , which may be adjusted to a horizontal position by means of adjusting screws  12  in the bottom plate  10 . In each corner of the bottom plate a hollow spindle  13  with external thread is secured. A solid spindle  14  with external thread which may be accommodated in the hollow spindle  13  is secured to the top plate  11 . Between these two spindles is a tubular spindle nut  15  having a hole with internal thread for the solid spindle  14  at the top. At the bottom of the spindle nut  15  is a hole likewise with internal thread for the hollow spindle  13 . The two spindles  13 , 14  have opposite thread. The spindle nut  15  at each corner of the bottom plate  10  is in a rotatable manner embedded in an intermediate frame  16  on which a motor unit is mounted. The motor unit drives an endless chain  17  running around a chain wheel  13  on each of the spindle nuts  15 . When the motor rotates in one direction the spindle nut  15  will climb up the hollow spindle  13  while the solid spindle  14  will be extended out of the tubular spindle nut  15 . When the direction of rotation of the motor is changed the spindles  13 , 14  will be retracted again. It is realized that the chain  17  may be replaced by a toothed belt and toothed pulley. A V-belt and discs for V-belt are also a possibility. Further, it is possible to use a separate motor for each, spindle nut  15  or a motor for spindle nuts in pairs, e.g. a motor for driving the two spindle nuts in one side and another motor for driving the two spindle nuts in the other side. The top plate  11  constitutes the supporting surface. It is realized that a telescopic extendable/retractable frame or cover plate may be arranged between the bottom plate  10  and the top plate  11  at least on the sides which are visible after the final assembly. 
     Another solution is shown in  FIGS. 5-7  of the drawing which comprises a bottom plate  20  on which two parallel positioned shafts  23 , 24  are mounted at a mutual distance by means of two rails  21 , 22 . An arm  25 , 26 , 27 , 28  is secured to each end of these shafts  23 , 24 . The upper end of the arms  25 - 28  is connected in pairs to a rod  29 , 30 , having a length corresponding to the distance between the two shafts  23 , 24 . A rotary arm  31  is fitted to one of the shafts  23 . The rear end of a linear actuator  32  is supported on one of the shafts  24  while the front end of its displaceable piston-like inner tube  33  is connected to the arm  31  on the other shaft  23 . When the inner tube  33  of the actuator is displaced outwards, the arms  25 - 28  of the shafts  23 , 24  rotate or extend upwards. When the inner tube  33  of the actuator is retracted the arms  25 - 28  of the shafts  23 , 24  are lowered. The linear actuator may e.g. be of the type disclosed in WO 02/29284 A1 Linak A/S. At each corner of the bottom plate  20  is mounted a small telescopic control unit  34  on top of which is mounted a carrying plate  35  constituting the supporting surface. At the upper end of the lifting arms  25 - 28  is mounted a wheel in mesh with the underside of the supporting surface  35 . It is understood that the bottom plate  20  may be equipped with adjusting screws  40  for adjusting the arrangement to a horizontal position. These adjusting screws  40  may be integrated in the lower end of the telescopic control units  34  at the corners. The telescopic control units  34  are here illustrated as three inside each other telescopic tube pieces. As mentioned earlier this embodiment may also comprise a. telescopic frame or rails. It is noted that the shafts  23 , 24  may be designed in a manner which allows them to be coupled with adjacent arrangements, e.g. tubular coupling pieces in extension of the shaft  23  as shown in the drawing. 
     The embodiment shown in  FIGS. 8-10  of the drawing comprises an upper box-shaped profile  50  which is open at the top and a lower box-shaped profile  51  which is open at the bottom. Between these two box-shaped profiles  50 , 51  is a chassis element  52  likewise designed as a box-profile. In this chassis element  52  two chain wheels  53 , 54  are embedded, over which an endless chain  55  runs. A right-angled, triangular plate element  56 , 57  is secured to each chain distance between the two chain wheels  53 , 54 , where an axle pin  58 - 61  is secured at each corner of the vertical side facing away from the chain wheels, said axle pin fitting into two inclined tracks  62 - 65  in the two box-shaped profiles  50 , 51 . The axle pins are guided with the ends in horizontal tracks in the chassis element  52 . The chain  55  is driven by a reversible electric motor  66  which over a worm gear  67  drives one of the chain wheels  54 . When the two triangular plate elements  56 , 57  are pulled away from each other, the upper box-shaped profile  50  will be raised out of the chassis element  52  while this synchronously is raised out of the lower box-shaped profile  51 . When the two triangular plate elements  56 , 57  are pulled towards each other the upper box-shaped profile  50  is lowered over the chassis element  52  while this is lowered into the lower box-shaped profile  51 . The triangular shape of the plate elements  56 , 57  causes the elements to be completely pulled together, even though they are displaced in the same plane. One of these arrangements may be arranged e.g. under a cabinet but it is also possible to place an arrangement at each side. It is noted that it is also possible to arrange a telescopic frame or cover plate as shut-off, preventing access into the hollow of the platform. This both prevents dirt from building up in the platform and also prevents personal injuries or squeezing e.g. as a result of a child extending a hand or foot into the platform. 
     A similar solution is shown in  FIGS. 11-13  which also comprises two box-shaped profiles  70 , 71  and a third box-shaped profile  72  is located in between these. These three box-shaped profiles  70 - 73  may in a telescopic manner be displaced in and out of each other. The drive mechanism is constituted by a spindle unit comprising a solid spindle  73  in mesh with a hollow spindle  74 , which again is in mesh with a tubular spindle nut  75 , which on the exterior at one end has a bevel wheel  76 . Such a spindle unit is located at each end of the box-shaped profiles  70 - 72  and is connected to a through-going drive shaft  77 , which at each end is equipped with a bevel wheel  78  in mesh with the bevel wheel  76  of the spindle nut  75 . The middle of the drive shaft  77  is furnished with a worm wheel  72  in mesh with a worm  79  on a reversible electric motor  800 . When the motor shaft moves in one direction the box-shaped profiles  70 - 72  are synchronously raised out of each other and when the direction of rotation is reversed the box-shaped profiles  70 - 72  are retracted into each other. 
     A somewhat similar construction is shown in  FIGS. 14-16  of the drawing which comprises two wedge elements  80 , 81  located next to each other, Between these two wedge elements  80 , 81  is located an axially displaceable wedge element  82 , which with a surface rests on one on the wedge elements  80 , while the other wedge element  81  rests on a surface of the displaceable wedge element  82  facing upwards. When the axially displaceable wedge element  82  is displaced axially it is raised from the lower wedge element  80  while it simultaneously urges the upper wedge element  81  upwards. When the axially displaceable wedge element  82  is moved in the other direction the upper wedge element  81  will be lowered while the displaceable element  82  slides down the lower wedge element  80 . The axially displaceable wedge element  82  may be moved by means of a chain as stated above or a spindle with a rotating spindle nut may be used causing the spindle to be displaced axially. Otherwise, the same principles as the above embodiment in  FIGS. 8-10  apply. 
     Another embodiment is shown in  FIGS. 17-18  which comprise similar but mirrored arrangements arranged in pairs comprising a lever  90 , mounted about a horizontal shaft  91  in a rotatable manner. At a distance along the lever  90  there is a spindle  92  driven by a reversible electric motor  93 . The spindle  92  is in mesh with a spindle nut  94  mounted on the lever  90 . When the motor  93  is activated the free ends of the four levers are raised due to the spindle nut climbing upwards on the spindle  92 . The spindle nut  94  is mounted on the lever  90  in a tiltable and displaceable manner causing it to adjust itself to the angular position of the lever  90 . If the direction of rotation of the motor  90  is reversed, the levers are lowered. All four spindles  92  may be driven synchronous through a toothed belt or chain  95  by a centrally located motor  93 . Like the other embodiments each spindle may be driven by a separate motor or in pairs. The spindle nut  94  is mounted on the lever in a tiltable and displaceable manner and the spindle  92  is fixed to the bottom plate  95 . On the other hand the spindle  92  may be mounted on the bottom plate  95  in a tiltable manner and the spindle nut  94  fixedly mounted on the lever  90 . In reality, the mutual rotation of the spindle/spindle nut is relatively small, which means that the spindle could be mounted on a yielding surface, which allows the rotation. Rolls  96  or circular arched supports may be mounted on the free ends of the levers  90 , which allow a more or less frictionless movement against the bottom of the object  97 , such as a kitchen base cabinet placed on top of it. 
     In  FIGS. 19-20  an entirely different embodiment is shown comprising two inside each other telescopically displaceable box-shaped elements  100 , 101 . One of the box-shaped elements  100  has a bottom plate  102 , while the other box-shaped element  101  does not necessarily have to be furnished with a top plate. The drive unit comprises a shaft  103  driven by the motor. A steel band  104  is secured to each end of the shaft, which over rolls  105 , 106  runs over the edge of the lower box-shaped element  100  and is secured to the underside of the subsequent box-shaped element  101 . A further development of the embodiment discloses three telescopically displaceable box-shaped elements  100 , 101 , 107  located inside each other, where the upper box-shaped element  107  is secured to the intermediate box-shaped element  101  by means of a steel band  180  over a roll  109  on the intermediate box-shaped element  101 . When the steel band  104  is wound on the shaft  103  the intermediate  101  and upper box-shaped element  107  will be telescopically displaced upwards. When the direction of rotation of the motor  108  is reversed the steel band  104  is slackened and the weight of and the weight on the box-shaped elements  107 , 101  will urge these downwards. It is noted that a steel band  109  is mounted in a corresponding manner on the motor driven shaft  103  which is secured to the opposite sides of the box-shaped elements. It is further noted that these steel bands  109  are guided the opposite way around the shaft  103  compared to the steel bands  104 . As an alternative to steel bands the construction may also be fitted with other types of bands e.g. plastic bands. Instead of a mutual motor-driven shaft  103  two motor-driven shafts for operating each side of the box-shaped elements may of course be provided. It is realized that the box-shaped elements does not necessarily have to be equipped with sides all the way around, it would be sufficient with two sides located opposite each other. These would of course have to be strengthened in the cross direction e.g. with supports on the bottom plate  102  and mutual guides. 
     For the sake of completeness,  FIG. 21  shows a variation of the embodiment in  FIG. 3 . Unlike  FIG. 3 , a solid spindle  200  with right-hand thread is here mounted on the bottom plate via a plate element  201 . This solid spindle  200  is furnished with a hollow spindle  202  with internal thread. The exterior of the hollow spindle  201  is designed with left-hand thread. On the outside of the hollow spindle  202  is a tube  203  with internal thread, On top of this tube is a mounting elate  204 , constituting the supporting surface for the object, such as a base cabinet, which should be carried by the tube  203 . The hollow spindle  202  is equipped with a toothed disc or chain wheel  205  at the bottom. All four spindle units are driven by an endless toothed belt or chain driven by a reversible electric motor. When the motor runs in one direction, the hollow spindle  202  will climb up the solid spindle  200  while the tube  203  is extended out of the hollow spindle  202 . 
       FIGS. 22-24  of the drawing show an embodiment based on a spindle unit as shown in  FIG. 21 . The hollow spindle  300  is here driven by an endless chain  301  driven by a reversible low voltage motor  302 , which drives a chain wheel  303  through a worm gear  304 . For guiding the chain  301  this is situated in a round-going profile rail  305 , functioning as chain housing to which the motor unit  302 - 304  further is secured. In the outermost position the motor  302  is stopped by end stop switches  306 , 307 , where one switch  306  hits the bottom plate  308 , while the other switch  307  hits a dog  309  on a rod  310  protruding from the bottom plate. On top of the spindle units is mounted a top plate  311  constituting the supporting surface for an object placed thereon. 
     The invention thus provides a solution, at which a table top mounted on base cabinets in an uncomplicated manner may be adjusted in height. The solution may be used where a table top is mounted on a continuous row of base cabinets as well as an interrupted row of base cabinets, e.g. where the table top is mounted on a base cabinet at each end. The platform according to the invention may be adapted to the individual base cabinets but may also be constructed to carry two or more base cabinets located next to each other. It is understood that two platforms may also be used for one cabinet e.g. a platform in each side with a width of 20 cm and depth of 45 cm may be used for a 60 cm wide cabinet. Such a platform may immediately be used for a slim cabinet e.g. with a width of 30 cm. In such a platform there is only one lifting arrangement at each end. 
     It is noted that the invention is not only intended for kitchens but may be used in other connections. An obvious example is in connection with laboratory and clinical equipment, where the cabinet elements by and large correspond to the kitchen cabinet elements. 
     When studying the invention from an overall point of view it is realized that the invention may be used for much more than height-adjustment of floor-mounted cabinet and drawer elements. The platform may e.g. be located on a table for height-adjustment of an object on the table. This is particularly relevant in connection with laboratory and clinical equipment.