Abstract:
In a patient bed system, comprising a patient bed, a support column for supporting the bed and a trolley for transporting the bed, the bed having arranged on it first coupling elements ( 22 ) which are intended for selective connection to second or third coupling elements ( 24, 26 ) on the support column and on the trolley respectively, at least one of the coupling elements ( 24 ) located on the support-column side has provided on it at least one sensor ( 102 ) for sensing the position of a first coupling element ( 22 ) connected to the bed ( 18 ) in relation to the column-side coupling element ( 24 ), the sensor ( 102 ) taking effect when the bed is located on the trolley and the latter assumes in relation to the support column a specific position for transferring the bed onto the latter.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation to U.S. patent application Ser. No. 11/598,526 filed on Nov. 13, 2006 and titled Patient Bed System, which claims foreign priority benefits under U.S.C. § 119 from German Patent Application No. 10 2005 054 220.4 filed on Nov. 14, 2005, the contents of which are incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a patient bed system, comprising a patient bed, a support column for supporting the bed and a trolley for transporting the bed, the bed having arranged on it first coupling elements which are intended for selective connection to second or third coupling elements on the column and on the trolley respectively. 
       BACKGROUND OF THE INVENTION 
       [0003]    Such a system is known, for example, from EP 457 246 B1. To transfer the bed onto the trolley, the latter is brought into a suitable position in relation to the support column. By means of the downward movement of the height adjustment device of the support column, the bed is first lowered, until it lies on the trolley. At the moment of transfer the first coupling elements on the bed are simultaneously in engagement with the second and third coupling elements on the column and on the trolley respectively. 
       SUMMARY OF THE INVENTION 
       [0004]    In order to ensure a satisfactory and as far as possible constraint-free transfer of the bed from the trolley onto the column, and vice versa, the coupling elements should be aligned exactly with one another before transfer, so that they can slide one into the other, as far as possible free of constraint. This presupposes that the column head, which, of course, as a rule, can be adjusted to vary the position of the patient on an operating table, is in an exactly defined position in relation to the floor of the operating theatre on which the trolley stands. Also, for any reason, the position of the patient bed on the trolley may not be exactly parallel to the floor of the operating theatre. Since these deviations sometimes cannot be detected or cannot so quickly be detected by the naked eye, it is proposed, according to the invention, that at least one of the coupling elements located on the support-column side has provided on it at least one sensor for sensing the position of a first coupling element connected to the bed in relation to the column-side coupling element, the sensor taking effect when the bed is located on the trolley and the latter assumes in relation to the support column a specific position for transferring the bed onto the latter. Expediently, the sensor is connected to a control controlling the actuating drive of the column head. When the sensor detects a deviation from the desired alignment of the bed-side coupling elements in relation to the column-side coupling elements or the coupling elements on the trolley, then the control, in response to a corresponding signal from the sensor, causes an adjustment of the column head until the coupling elements are exactly in alignment with one another. The sensor may be formed, for example, by a deflectable finger which senses one of the contours of the bed-side or trolley-side coupling elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    The following description explains the invention by means of exemplary embodiments, in conjunction with the accompanying drawings in which: 
           [0006]      FIG. 1  shows a diagrammatic illustration of a patient bed system comprising a patient bed, a trolley for a bed and a support column for a patient bed, 
           [0007]      FIG. 2  shows a partially diagrammatic illustration of the three coupling elements cooperating with one another, 
           [0008]      FIG. 3  shows a diagrammatic section through the three coupling elements simultaneously in engagement with one another, 
           [0009]      FIG. 4  shows a partially diagrammatic illustration of a first coupling element alone, which is arranged on a bed-side part, 
           [0010]      FIG. 5  shows a diagrammatic illustration of the three coupling elements simultaneously in engagement with one another, 
           [0011]      FIGS. 6 and 7  show in each case an illustration of the three coupling elements during the transfer of the bed from the support column onto the trolley, and 
           [0012]      FIGS. 8 and 9  show in each case illustrations, corresponding to  FIGS. 6 and 7 , during the transfer of the bed from the trolley onto the support column. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]    The patient bed system, illustrated diagrammatically in  FIG. 1 , comprises a support column, designated in general by  10 , of an operating table, with a column foot  12  and with a column head  14  mounted vertically adjustably on the latter. The height adjustment device is not illustrated. It may be designed in any conventional way. As a rule, this may be a hydraulic or mechanical lifting device. 
         [0014]    Located on the left, next to the support column, is a trolley, designated in general by  16 , which carries a bed or table board  18  of the operating table. The trolley  16  comprises two side frame parts  20  which are connected to one another by means of crosspieces, not illustrated, as is illustrated in EP 457 246 B1. The trolley  16  can be moved up to the support column  10  such that the latter lies between the side frame parts  20 . 
         [0015]    On the longitudinal side edges of the bed  18 , first coupling elements  22  are arranged, which are intended for engagement into second coupling elements  24  on the column head  14  or third coupling elements  26  on the side frame parts  20  of the trolley  16 , in order to connect the bed  18  either to the support column  10  or to the trolley  16 . The more detailed configuration of the coupling elements and their mode of operation will now be described in more detail below. 
         [0016]    In  FIG. 2 ,  28  designates a connecting frame which comprises a middle plate  30  and two side cheeks  32  which project downward at its longitudinal ends and only one of which is illustrated. The middle plate  30  has on its top side bedding  34  for connection to the actual patient bed  18  which is mounted on the connecting frame  28  pivotably about the bedding axis  36  running transversely with respect to the longitudinal direction of the said patient bed. Each of the cheeks  32  carries on its inside a first coupling element  22 . The latter has the configuration of a broad tenon with an outer contour  38 , and also a slot-shaped clearance  40  with an inner contour  42 . 
         [0017]    Below the connecting frame  28  is located a saddle  44 , illustrated only partially, which is part of the column head  14 . It is of C-shaped construction, in a similar way to the connecting frame  28 , with a middle web  46  and with two side parts  48 , only one of which is illustrated. The side part  48  has on its outside a reception pocket, forming the second coupling element  24 , for receiving the first coupling element  22 , the reception pocket having an inner contour  50  adapted to the outer contour  38  of the first coupling element  22 . The middle web  46 , near its respective side part  48 , carries on its top side a centering pin  52  which is intended for engagement into a complementary pin receptacle  54  formed on the underside of the middle plate  30  of the connecting frame  28 . 
         [0018]    In the illustration of  FIG. 2 , there projects into the reception pocket of the second coupling element  24  a guide tenon which forms the third coupling element  26  and which is fastened to the trolley  16  via a pedestal  56  and is intended for engagement into the clearance  40  of the respective first coupling element  22 . The said guide tenon has an outer contour  58  corresponding to the inner contour  42  of the first coupling element  22 . 
         [0019]    If all three coupling elements  22 ,  24 ,  26  are simultaneously in engagement with one another during the transfer of the bed from the trolley onto the support column, and vice versa, they are nested one in the other, as may be seen in the diagrammatic illustration of  FIG. 3 . The tenon forming the third coupling element  26  lies in the clearance  40  of the first coupling element  22  which, in turn, engages into the reception pocket forming the second coupling element  24 , so that all three coupling elements lie as it were in one plane. This results in a type of construction which is very flat transversely with respect to the longitudinal direction of the bed  18 . 
         [0020]    The further benefits of this arrangement may be gathered from the following description of the locking mechanism, by means of which the bed  18  is connected alternately either to the column head  14  or to the trolley  16 . 
         [0021]      FIG. 4  shows a diagrammatic top view of the inside of a cheek  32  of the connecting frame  28 . The first coupling element  22 , on which two locking elements  60  and  62  are mounted adjustably, can be seen once again. The locking elements  60  and  62  are designed in each case in the form of a two-armed lever which is mounted pivotably about a pivot axis  64  or  66  and which is prestressed in each case clockwise by means of a torsion spring  68  or  70 . The locking element  60  is intended for locking the bed  18  to the column head  14 . For this purpose, one lever arm  72  is provided with a hooked extension  74  which is intended for engagement into a clearance  76  on the inner contour  50  of the second coupling element  24  ( FIG. 5 ). The locking element  62  is intended for locking the bed  18  to the trolley  16 . For this purpose, the lever arm  78  of the locking element  62  has a hooked extension  80  which is intended for engagement into a clearance  82  on the outer contour  58  of the tenon-shaped third coupling element  26  ( FIG. 5 ). 
         [0022]    The mode of operation of the locking elements during the transfer of the bed  18  from the column  10  onto the trolley  16  will now be described with reference to  FIG. 5 to 7 . 
         [0023]      FIG. 5  shows the three coupling elements  22 ,  24  and  26  in complete engagement with one another. In this state, both locking elements  60  and  62  are pivoted into their release position. In the case of the locking element  60 , this takes place in that the lever arm  84  opposite to the lever arm  72  slides with control edge  86  on a control cam  88  formed on the third coupling element  26  and is at the same time pivoted anti-clockwise, that end  90  of the first lever arm  72  which is opposite to the hooked extension  74  of the first locking element  60  penetrating into a semicircular clearance  92  in the outer contour of the third coupling element, as shown in  FIG. 5 . In the same way, the second locking element  62  is pivoted anti-clockwise, in that a lever arm  94  opposite to the lever arm  78  slides with a control edge  96  on a control cam  97  formed on the second coupling element  24 , once again that end  98  of the first lever arm  78  which is opposite to the hooked extension  80  penetrating into a semicircular clearance  100  in the second coupling element  24 , as shown in  FIG. 5 . 
         [0024]    During the transfer of the bed  18  onto the trolley  16 , the column head  14  of the support column  10  is lowered out of the position illustrated in  FIG. 5 , as can be seen in  FIGS. 6 and 7 .  FIG. 6  shows that, with the commencement of the downward movement of the column head  14  and consequently of the second coupling element  24 , the right-hand locking element  62  is pivoted clockwise under the action of the control cam  97 , sliding on a control edge  101  of the lever end  98 , of the second coupling element  24 , so that the hooked extension  80  is moved into the clearance  82 . Even in the position illustrated in  FIG. 6 , the bed  18  could no longer be lifted off from the trolley  16 . When the column head  14  is lowered further, as shown in  FIG. 7 , the hooked extension  80  of the second locking element  62  is pivoted completely into the clearance  82  in the third coupling element  26 , so that the bed  18  is locked firmly to the trolley  16 . In this position, the hooked extension  80  is held as a result of the action of the torsion spring  70 . Conversely, during the raising of the column head  14  out of the position illustrated in  FIG. 7 , the locking element  62  would be pivoted anti-clockwise, so that the lock between the first and the third coupling element is cancelled. 
         [0025]      FIGS. 8 and 9  show the locking operation during the transfer of the bed  18  from the trolley  16  onto the support column  10 . In this case, starting from the position illustrated in  FIG. 5 , the column head  14  is raised, so that the third coupling element  26  slides downward out of the clearance  40  of the first coupling element  22 . At the same time, in this case, the first locking element  60  is positively pivoted clockwise by the control cam  88  sliding on a control edge  103  on the lever end  90  and located on the third coupling element  26 , so that the hooked extension  74  of the first locking element  60  engages into the clearance  76  in the column-side second coupling element  24 , as shown in  FIG. 8 . When the third coupling element is drawn out of the first coupling element, the bed  18  is locked firmly to the column head  14 , as shown in  FIG. 9 . Conversely, when the third coupling element  26  is introduced into the clearance  40  of the first coupling element  22 , the locking element  60  is pivoted anti-clockwise, so that the lock between the second and the first coupling element is released. The above description shows that the two locking elements  60  and  62  are in each case pivoted positively during the coupling operations, so that a reliable lock between the bed and the column head, on the one hand, and the bed and the trolley, on the other hand, is ensured. 
         [0026]    It can be seen, furthermore, that, starting from the position according to  FIG. 5 , in which both locking elements  60  and  62  are pivoted into their release position, if the bed  18  were raised with respect to the column head and the trolley, both locking elements would be pivoted clockwise and consequently be locked. The bed  18  is thus reliably prevented from being lifted out of the position illustrated in  FIG. 5 . 
         [0027]    In order to achieve an as far as possible friction-free transfer of the bed from the column onto the trolley, or vice versa, the coupling elements  22 ,  24  and  26  should lie exactly in alignment with one another. If they are tilted with respect to one another, malfunctions may occur. In order to avoid this, the saddle  44  has arranged on it, within the reception pocket of the second coupling element  24 , a sensor, designated in general by  102 , which is intended to sense the position of the third coupling element  26  in relation to the second coupling element  24 . The sensor comprises a rotatably mounted disc  104  which is connected, for example, to a potentiometer tap and on the outside of which is provided an eccentrically arranged sensing finger  106 . This sensing finger  106  engages into a clearance  108  which is formed on a wide side of the third coupling element  26  and which is delimited by two control edges  110  and  112 . If the transport trolley  16  and the column head  14  are inclined with respect to one another during the take-over operation, so that the coupling elements  24  and  26  are not aligned with one another in the desired form, the sensing finger  106  butts against one of the control edges  110 ,  112 . The disc  104  is thereby rotated. This rotation is detected, for example, via the connected potentiometer and can be converted into a control signal which is supplied, in turn, to the control of the column head  14 . The column head  14  can thereby be adjusted such that the second and the third coupling element are aligned with one another, in order to allow friction-free coupling. 
         [0028]    The conversion of the deflection of the sensing finger  106  into a control signal can, of course, also be effected in another suitable way. Likewise, the sensor can be arranged in such a way that it senses a contour of the first, bed-side coupling element  22 , since the alignment of the first coupling elements with respect to the column-side second coupling elements  24  is of primary importance. 
         [0029]    While the present invention has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this invention may be made without departing from the spirit and scope of the present invention.