Abstract:
A bath tub lifter for seniors or disabled persons comprises a frame to rest on a portion of a bath tub, a seat plate and a backrest in connection therewith, a lifting means for adjusting the height of the seat plate and the backrest between a lowermost and an uppermost end position, the lifting means comprising a driving means mounted to the backrest and a telescopic lifting tube to be actuated by the driving means, a spindle base in connection with the lifting tube for providing support against the frame, and an automatic lock-release device coupling the backrest and the seat plate above the lowermost end position and releasing the backrest and the seat plate in the lowermost end position, the lock-release device comprising at least one lock bolt movably held at the backrest for coupling the backrest and the seat plate above the lowermost end position, and at least one sliding guide formed at the seat plate for actuating the at least one lock bolt.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates to a bath tub lifter for seniors or disabled persons. The invention further relates to a lock-release device for a bath tub lifter for seniors or disabled persons.  
       BACKGROUND OF THE INVENTION  
       [0002]     Bath tub lifters are, for example, employed in nursing homes and hospitals for facilitating the bathing or washing of invalid, disabled or elderly persons in bath tubs or the like. It is a disadvantage of these known bath tub lifters that often the backrest and the seat plate can not be separated or only be separated with some efforts. These bath tub lifters are therefore often transported or removed from the bath tub as a whole with great physical effort.  
       SUMMARY OF THE INVENTION  
       [0003]     Starting from this situation, the underlying invention is a bath tub lifter for seniors or disabled persons such that the removal or transport of a bath tub lifter is possible without great effort. Furthermore, a lock-release device is provided for a bath tub lifter the function of which is particularly secure and which has an extremely simple design.  
         [0004]     One exemplary embodiment of the bath tub lifter according to the present invention comprises 
        a floor frame to rest on the floor of a bath tub,     a seat plate and a backrest in connection therewith,     a lifting means for adjusting the height of the seat plate and the backrest between a lowermost and an uppermost end position, the lifting means comprising: 
            a driving means mounted to the backrest, and     a telescopic lifting tube to be actuated by the driving means,    
            a spindle base in connection with the lifting tube for providing support against the floor frame, and     an automatic lock-release device coupling the backrest and the seat plate above the lowermost end position and releasing the backrest and the seat plate in the lowermost end position, the lock-release device comprising: 
            at least one lock bolt movably held at the backrest for coupling the backrest and the seat plate above the lowermost end position, and     at least one sliding guide formed at the seat plate for actuating the at least one lock bolt.    
               
 
         [0014]     That means, if the seat plate and the backrest are driven into the lowermost end position of their travel, the backrest and the seat plate are automatically separated there. This is only performed by their downward movement. Corresponding tools as are required in bath tub lifters known from prior art are not necessary. Accordingly, the backrest with the driving means can be separately removed without any mounting works.  
         [0015]     According to an advantageous embodiment, the at least one lock bolt can be moved between a release position and a lock position. In the release position, the backrest and the seat plate are released from one another, while in the lock position they are coupled to one another. The corresponding states are achieved by the respective position of the at least one lock bolt.  
         [0016]     It is advantageous for the at least one sliding guide to comprise a support section for coupling the backrest and the seat plate to one another. Advantageously, the at least one sliding guide also comprises a transfer section for actuating the at least one lock bolt. Accordingly, the positions of the at least one lock bolt are achieved by the at least one sliding guide.  
         [0017]     Preferably, the transfer section extends diagonally with respect to a vertical line. Due to the diagonal extension of the transfer section, the at least one lock bolt is steadily and slowly transferred between its positions.  
         [0018]     According to an advantageous embodiment, the at least one lock bolt has a central longitudinal axis. It is convenient for the at least one lock bolt to comprise an end cooperating with the at least one sliding guide, this end comprising an inclined surface extending diagonally with respect to the central longitudinal axis and a contact surface extending essentially perpendicularly to the central longitudinal axis. Due to the inclined surface, the at least one lock bolt can be again steadily displaced between its positions. In the area of the contact surface, the backrest and the seat plate are coupled to each other.  
         [0019]     It is advantageous if a radially projecting securing element is in connection with the at least one lock bolt. This securing element serves as protection from losing the at least one lock bolt.  
         [0020]     The object concerning the lock-release device is achieved according to the invention by the lock-release device comprising at least one lock bolt being movable between 
        a lock position for coupling a backrest and a seat plate of a bath tub lifter to each other, and     a release position for releasing the backrest and the seat plate from one another, 
 
 the at least one lock bolt being automatically actuated by means of a sliding guide. 
       
 
         [0023]     An external actuation for displacing the at least one lock bolt is consequently not necessary in this case. The lock-release device serves for the connection of the backrest with the seat plate and its release from the seat plate. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     Below, the invention will be described more in detail with reference to a preferred embodiment in connection with the drawing, wherein:  
         [0025]      FIG. 1  shows a partially cut section of a bath tub lifter according to the invention from behind,  
         [0026]      FIG. 2  shows an enlarged detail of  FIG. 1  there marked with “A”, and  
         [0027]      FIG. 3  shows an enlarged detail of  FIG. 1  there marked with “B”. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     A bath tub lifter shown in  FIG. 1  as a whole comprises a floor frame  1  to be placed onto the floor of a bath tub (not shown), a seat plate  2  and a backrest  3  being in pivotable connection with the same. The seat plate  2  provides a plane seat for a person to be bathed, while the backrest  3  provides a plane backrest for this person to lean against. For adjusting the height of the seat plate  2  and the backrest  3 , the bath tub lifter comprises a controllable lifting means. The lifting means comprises a telescopic lifting tube  4  and a driving means  5  for actuating the lifting tube  4 . The lifting tube  4  is in contact with the floor frame  1  and the backrest  3 .  
         [0029]     The floor frame  1  has an essentially rectangular basic shape. Suction feet  6  are provided at the bottom of the floor frame  1 , i.e. on the side opposite a bath tub bottom when the lifter is used according to its purpose. They serve for securely positioning the floor frame  1  in a bath tub and for supporting the floor frame  1  against a bath tub bottom. In the back area of the floor frame  1 , two spaced bearing nose pairs  7  are provided in which lower ends  8  of supports  9  are pivotably supported. The upper ends of the supports  9  are hinged at the front bottom of the seat plate  2 . In the front area of the floor frame  1 , two further supports  10  are pivotably supported which are hinged at the seat plate  2  at the rear bottom. Supports  9 ,  10  form lift scissors. In the middle between the bearing nose pairs  7 , a bearing means  11  for supporting the lifting tube  4  is provided.  
         [0030]     On the backside of the backrest  3 , the driving means  5  of the lifting means is mounted. In one exemplary embodiment the driving means  5  is an electromotor and can be actuated by a corresponding operating device, for example by a user of the bath tub lifter or a nurse. The driving means  5  is in connection with the lifting tube  4  so as to transmit torque. For lifting or lowering the seat plate  2  and the backrest  3 , an internal tube or internal tubes of the lifting tube  4  are extended or retracted, respectively. This extending or retracting motion is achieved by the driving means  5 .  
         [0031]     For connecting the backrest  3  with the seat plate  2 , two identically designed lock bolts  12  are provided which essentially have a round external shape. Each lock bolt  12  comprises a central longitudinal axis  13  and is held at the backrest  3  to be axially movable. To this end, corresponding bearing noses  14  are formed at the backside of the backrest  3 . Preferably, the bearing noses  14  comprise closed openings adapted to the external form of the lock bolts  12  which intersperse the lock bolts  12 . This results in a guide of the lock bolts  12  along their central longitudinal axis  13 . The two lock bolts  12  are aligned, but spaced. They are arranged to extend horizontally and are perpendicular to the lifting tube  4 .  
         [0032]     Each lock bolt  12  comprises two opposite ends  15 ,  16 . The internal ends  15  of the two lock bolts  12  adjoin the outside of the round lifting tube  4  in the position of the seat plate  2  and the backrest  3  shown in  FIG. 1 . They face each other. Each internal end  15  is formed by a lower straight contact surface  17  and an upper inclined surface  18 . The contact surface  17 , which can also be adapted to the bend of the lifting tube  4 , here extends at right angles with respect to the longitudinal central axis  13 , while the inclined surface  18  extends diagonally to the central longitudinal axis  13 . Starting from the contact surfaces  17 , the lock bolts  12  extend in the area of their corresponding inclined surfaces  18 . Each external end  16  is formed by a lower inclined surface  19  and an upper contact surface  20 . The inclined surface  19  again extends diagonally to the central longitudinal axis  13 , while the contact surface  20  again extends at right angles with respect to the central longitudinal axis  13 . Starting from the contact surface  20 , the lock bolt  12  extends in the area of the inclined surface  19 . The projected vertical extension of the inclined surface  19  is about three to four times the vertical extension of the contact surface  20 . The function of the surfaces  17  to  20  will be discussed below.  
         [0033]     The seat plate  2  comprises an essentially horizontal seat surface facing upwards from which a plurality of vertical webs project downwards. It comprises two inner vertical webs  21  extending in parallel one to another, two central vertical webs  22  extending in parallel one to another, and two outer vertical webs  23  extending in parallel one to another. The vertical webs  21 ,  22  and  23  also extend in parallel one to another. The two vertical webs  21  can also be integral. In this case, they are connected by a corresponding front connecting web. The vertical webs  22  and  23 , too, can correspondingly be integral. At or in each vertical web  21 , a sliding guide  24  is provided inside. The seat plate  2  altogether has two identical segment-shaped sliding guides  24 . The groove-like sliding guides  24  opened to the inside are each formed by a lower stop section  26 , a transfer section  25 , a stop section  27 , and an upper support section  28 . The stop section  27  extends vertically while the transfer section  25  adjoining at the bottom of the stop section  27  extends diagonally outwards towards the horizontal stop section  26 . The stop section  26  ends at an internal wall  29  of the corresponding vertical web  21 . The support section  28  at the top borders on the stop section  27  and extends vertically to the same. The bend of the projecting support section  28  essentially corresponds to the bend of a lock bolt  12  in the area of its external end  16 . The distance of a stop section  27  to the corresponding internal wall  29  approximately corresponds to the projected horizontal extension of the inclined surface  19 . Equally, the inclination of the inclined surface  19  and the transfer section  25  are essentially identical. The sliding guides  24  are deepest in the area of the stop sections  27 . Two outer side flaps  30  are hinged laterally off the seat plate  2 .  
         [0034]     A spindle base  31  is connected to the lower end of the lifting tube  4 . The same is in separable articulated connection with the bearing device  11  of the floor frame  1  and there supports the lifting tube  4 . The spindle base  31  has a symmetric shape. It comprises two opposite guide recesses  32  each of which expands downwards. Each guide recess  32  comprises a lower straight release section  33  and an inclined section  34  adjoining the same. The release sections  33  of the two guide recesses  32  extend in parallel one to another and extend in the direction of the central longitudinal axis  35  of the lifting tube  4 . They are staggered inwards with respect to the round casing of the lifting tube  4 , i. e. towards each other. The inclined sections  34  extend from the release sections  33  upwards and outwards, i. e. away from each other—and end at the bottom of the casing of the lifting tube  4 . They are located in the area of the lifting tube  4  where the diameter of the same is largest. The horizontal width of the release and inclined sections  33 ,  34  approximately corresponds to the horizontal width of the contact surfaces  17  of the lock bolts  12 . The inclination of the inclined sections  34  approximately corresponds to the inclination of the inclined surfaces  18 . The guide recesses  32  are open to the outside and limited by a guide wall  36  at one side.  
         [0035]     Below, the function of the bath tub lifter according to the invention will be described more in detail. The lifting tube  4 , the outer tube of which is mounted to the backside of the backrest  3  by means of fastening elements  37 , can be extended or retracted, respectively, by the actuated driving means  5 . Thereby, the height of the seat plate  2  and the backrest  3  can be adjusted as desired. The lift scissors formed by the supports  9 ,  10  provide a guide.  
         [0036]     According to  FIG. 1 , the seat plate  2  and the backrest  3  are in their uppermost end position. That means, the seat plate  2  and the backrest  3  have been driven upwards. The lock bolts  12  adjoin the outside of the casing of the lifting tube  4  with their contact surfaces  17  lying opposite. This contact is achieved by the sliding guides  24 . One sliding guide  24  is allocated to each lock bolt  12 . The lock bolts  12  simultaneously adjoin the stop sections  27  of the sliding guides  24  with their contact surfaces  20 . That means, the lock bolts  12  engage the seat plate  2  via the sliding guides  24 . In the process, the end sections of the two lock bolts  12  adjoining the contact surfaces  20  contact the support sections  28  of the sliding guides  24 , whereby the seat plate  2  and the backrest  3  are coupled to each other.  
         [0037]     In case of an adjustment of the height of the seat plate  2  and the backrest  3 , the contact surfaces  17  move along the lifting tube  4  on its casing. Moreover, the contact surfaces  20  adjoin the contact sections  27 .  
         [0038]     When the seat plate  2  and the backrest  3  are lowered from the position shown in  FIG. 1  to the lowermost end position, the lock bolts  12  reach the area of the spindle base  31 . At the spindle base  31 , the contact of the contact surfaces  17  at the lifting tube  4  ends. The contact surfaces  17  of the lock bolts  12  are here pressed into the guide recesses  32  of the spindle base  31  by the transfer sections  25  of the sliding guides  24 . The transfer sections  25  are designed in such a manner that the contact surfaces  17  always follow the contours of the guide recesses  32 . With the transfer sections  25  and the inclined sections  34  representing a connection between the casing of the lifting tube  4  and the release sections  33 , the two lock bolts  12  are gradually moved towards each other. In the lower area of the release sections  33 , the lock bolts  12  then adjoin the stop sections  26 . A further movement is not possible due to the stop sections  26 . In this position, the backrest  3  can be removed from the seat plate  2 . The guide wall  36  provides a secure guide of the lock bolts  12  in the guide recesses  32 . The inclined surfaces  19  permit a particularly good guide of the lock bolts  12  along the transfer sections  25 .  
         [0039]     If the seat plate  2  and the backrest  3  are driven upwards again from this lowermost end position, the lock bolts  12  are moved away from one another in the opposite direction by the inclined sections  34  of the spindle base  31  and the inclined surfaces  19  of the sliding guides  24 , resulting in a coupling of the seat plate  2  to the backrest  3 . In the process, the inclined surfaces  18  provide for the lock bolts  12  being able to troublefree slide along the inclined sections  34 . The inclined surfaces  19  also serve for lock bolts  12 , which are possibly not totally shifted back, to be shifted back to their extreme end position when the backrest  3  is erected.  
         [0040]     That means the locking between seat plate  2  and backrest  3  is controlled by the normal motion course of the seat plate  2  and the backrest  3 . In the process, the locking is automatically effected when the seat plate  2  and the backrest  3  are driven upwards from their lowermost end position. When they are lowered into the lowermost end position, this locking is automatically released. Accordingly, there is a forced control by the sliding guides  24 .  
         [0041]     Each of the lock bolts  12  comprises an annular groove  38  in each of which a securing ring  39  is received. In the position of the lock bolts  12  which is shown in  FIG. 1 , the securing rings  39  adjoin the central bearing noses  14 . The securing rings  39  prevent the lock bolts  12 , which can be loosely axially moved, from getting lost.  
         [0042]     The bath tub lifter according to the invention is characterized by a particularly low number of components. Moreover, the actuation of the lock bolts  12  is nearly noiseless.  
         [0043]     While preferred embodiments of the invention have been shown and described herein, it will be understood that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Accordingly, it is intended that the appended claims cover all such variations as fall within the spirit and scope of the invention.