Abstract:
The invention relates to an operating table column ( 10 ) for an operating table ( 100 ), said operating table column comprising a basic body ( 12 ) and a column head ( 14 ) to which a patient support ( 103 ) may be connected. Further, the operating table column ( 10 ) comprises a first linear actuator ( 20 ) and a second linear actuator ( 22 ) which are independently adjustable for changing the position of the column head ( 14 ) relative to the basic body ( 12 ). The first linear actuator ( 20 ) and the second linear actuator ( 22 ) each are oriented and arranged so as to perform an actuating motion in vertical direction when activated. The first linear actuator ( 20 ) is mechanically connected to the column head ( 14 ) via a first connecting area ( 30 ), and the second linear actuator ( 22 ) is mechanically connected to the column head ( 14 ) via a second connecting area ( 32 ). The column head ( 14 ) comprises a length adjustment assembly ( 36, 50 ) through which the distance between the first connecting area ( 30 ) and the second connecting area ( 32 ) is changeable during an actuating motion of the first linear actuator ( 20 ) and/or the second linear actuator ( 22 ).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    Applicant hereby claims foreign priority benefits under U.S.C. §119 from German Patent Application No. DE 10 2014 109 375.5 filed on Jul. 4, 2014, the contents of which are incorporated by reference herein. 
       TECHNICAL FIELD 
       [0002]    The invention relates to an operating table column having a basic body and a column head to which a patient support is attachable. The invention further relates to an operating table having an operating table column of this type. 
       BACKGROUND 
       [0003]    Prior to and during an operation of a patient placed on the patient support, the patient support is brought to a position which facilitates a surgical intervention on the patient. In order to do so, pivoting of the patient support by large angles may be required. Also the height of the operating table&#39;s patient support should be adjustable within a range as wide as possible. The operating table ideally further allows for very small heights of the patient support, which requires compact construction of the operating table column. 
         [0004]    The following three different types of operating tables are typically used in hospitals: stationary operating tables, movable operating and mobile operating tables. Stationary operating tables have an operating table column permanently fixed to the floor of an operating room and normally do not comprise an operating table base, and energy is supplied to them via fixedly installed cables. With these stationary operating tables, the patient support can easily be detached and re-attached and is transportable by means of a dedicated transport apparatus. With this transport apparatus, a patient resting on the patient support can be transported to and away from the operating room. 
         [0005]    Movable operating tables have an operating table base connected to the operating table column an allowing for free positioning in the operating room, and a patient support which can be detached from and re-attached to the operating table column. Moving of the operating table column is performed by means of a column transporter provided therefore, or, in the case of self-mobile movable operating tables, by means of incorporated extractable transport rollers. 
         [0006]    Operating table bases of mobile operating tables include rollers for moving the operating table such that they can be moved without auxiliary means and are suited for transporting a patient. Further, with mobile operating tables, the patient support usually is fixedly coupled to the operating table column and is not separated from the operating table column in hospital practice. Mobile operating tables may further employ electric traction drives, in particular including soft start and safety brake function, in order to move the mobile operating table by means of the electric traction drive. 
         [0007]    Energy supply of movable operating tables and mobile operating tables can be accomplished via accumulator batteries which are preferably integrated in the operating table, and in particular are arranged in the operating table column base or in the operating table column. 
         [0008]    Stationary operating tables as well as movable operating tables or mobile operating tables may employ components which can be adjusted by means of an electric motor, such as an operating table column which is length adjustable by means of an electric motor for height variation of a patient support attached to the operating table column, an operating table column head which is adjustable about two orthogonal axes for variation of tilt and swing of the patient support connected to the operating table column head, and/or components of the patient support that can be adjusted by means of an electric motor. 
         [0009]    Herein, tilt means pivoting the patient support about a rotational axis which is orthogonal to a vertical plane in which the patient support&#39;s longitudinal axis extends. Swing refers to pivoting the patient support about the longitudinal axis thereof, or about a rotational axis parallel to the patient support&#39;s longitudinal axis and extending in a vertical plane including the patient support&#39;s longitudinal axis. In case there is no patient support connected to the column head of the operating table column, the definitions of tilt and swing relate to adjustments of the column head as would occur with a patient support attached. 
         [0010]    From document DE 10 2011 000 628 A1 an operating table column is known comprising three actuators for adjusting swing and tilt. The mechanical construction thereof is rather complicated and requires much construction space. Rigidity and freedom from play of the tilt function are adversely influenced by the rotatable tilt cylinder. The kinematic coupling between the swing and tilt functions leads to interference of these functions. 
         [0011]    From document DE 196 23 580 C2 a lifting column is known comprising three vertical lifting cylinders for adjusting a patient support. 
       SUMMARY 
       [0012]    In view of the prior art known, it is the object of the invention to specify an operating table column which allows for large ranges of adjustment of tilt, swing, and/or height of the column head of the operating table column, employing a simple construction. 
         [0013]    This object is achieved by an operating table column including a basic body and including a column head to which a patient support is connectable, wherein the operating table column comprises a first linear actuator and a second linear actuator which are independently adjustable for changing the position of the column head relative to the basic body, the first linear actuator and the second linear actuator each are oriented and arranged so as to perform an actuating motion in vertical direction upon activation thereof, the first linear actuator is mechanically connected to the column head via a first connecting area and the second linear actuator is mechanically connected to the column head via a second connecting area, the column head comprises a length adjustment assembly through which the distance between the first connecting area and the second connecting area is changeable during an actuating motion of the first linear actuator and/or the second linear actuator, and the first linear actuator and the second linear actuator are the only force transmitting elements between the column head and the basic body. 
         [0014]    By means of an operating table column, the column head, or a patient support connected thereto, can be tilted via different actuations, or the swing thereof can be varied. In addition, with a simultaneous actuating motion of the linear actuators in the same direction of adjustment, the column head can be varied in height, i.e. can be lifted or lowered, respectively, without changing the swing or tilt. 
         [0015]    No further mechanical connection for force transmission is provided between column head and basic body, besides the two linear actuators. In addition to the thus simplified construction of the operating table column, this bears the advantage that only a simple covering of the column basic body is required, having two apertures for the two linear actuators. Further, one aperture for a connection for energy and signal transmission is required to be formed in the column basic body covering. Bellows which are required for covering the column basic body in most of the prior art operating tables can be omitted. Due to the fact that the first and/or the second linear actuator transfer any torque acting about a connecting line between the first connecting area and the second connecting area preferably to the basic body of the operating table column, in particular the tilting torques occurring with swing of the patient support can be securely held. It is particularly advantageous if the two linear actuators are permanently mechanically fixed to the basic body. This further simplifies the construction. Further, high stability is achieved at low production costs. With this formation, lifting of the column head can be simply accomplished by simultaneously extending the first and second linear actuators. 
         [0016]    Further, it is advantageous if the linear actuators each perform an exclusively vertical actuating motion, i.e. an adjusting motion parallel to the perpendicular longitudinal axis of the operating table column. This is in particular achieved by the first and second linear actuators being oriented and arranged such that the longitudinal axes thereof are parallel during any actuating motions thereof. Therein, the actuating motions preferably extend along the respective longitudinal axes of the first and second linear actuators. Preferably, the length adjustment assembly connects the first connecting area of the first linear actuator with the second connecting area of the second linear actuator. The length adjustment assembly is preferably formed such that an adjustment of the distance between the first connecting area and the second connecting area due to a different actuating motion of the first and second linear actuators is performed passively. The terms swing and tilt have already been explained in the introduction to the description, and are used throughout the description and in the claims according to that explanation. 
         [0017]    The first and second linear actuators may, for example, be realized as a hydraulic cylinder or as a lead screw drive driven by an electric motor. 
         [0018]    Further, it is advantageous if both linear actuators are connected to a height adjustable part of the basic body. In this case, the total range of height adjustment is the sum of the height adjustment of the basic body and the height adjustment caused by the linear actuators. An additional actuator, preferably a hydraulic cylinder or a lead screw drive driven by an electric motor, is provided for height adjustment of the height adjustable part of the basic body. A lead screw drive is a drive comprising a lead screw and converting a rotary motion into a translatory motion. This allows for a relatively large height adjustment range. 
         [0019]    Furthermore, it is advantageous if the column head includes a pivoting unit for pivoting, in the connected state, a patient support which is connected to or is connectable to the column head. The pivoting unit can be pivoted about at least a first rotational axis and about a second rotational axis. The first rotational axis and the second rotational axis are perpendicular to each other when projected onto a horizontal plane. Likewise, the longitudinal axis of the patient support and the first rotational axis are perpendicular to each other when projected onto a horizontal plane. Thereby it is possible to pivot the patient support about two principal axes such that swing and tilt of the patient support can be adjusted in a simple manner. 
         [0020]    It is particularly advantageous if the longitudinal axis of the first linear actuator and the longitudinal axis of the second linear actuator are spaced in the direction of the longitudinal axis of the patient support, and preferably are spaced by a distance within the range of 10 cm to 50 cm. In the case of patient supports where a natural definition of a longitudinal axis is impossible, the longitudinal axis of the patient support is determined as a line parallel to the center axis of a patient resting thereon in a centered position according to normal use. Preferably, the center of gravity of the patient support is located on the longitudinal axis thereof. Thus, there are no or only small torques for a rotation about the longitudinal axis of the patient support acting on the mechanical elements of the operating table column. 
         [0021]    Further, it is advantageous to mechanically couple the column head via a first pivot bearing in the first connecting area with the upper end of the first linear actuator so as to be pivotable about a first rotational axis, and to mechanically couple the column head via a second pivot bearing in the second connecting area with the upper end of the second linear actuator so as to be pivotable about a second rotational axis. Herein, the first and second rotational axes are parallel. This allows for pivoting of the column head about a rotational axis which is parallel to the rotational axes of the first and second pivot bearings, or which, depending on how the linear actuators are controlled, corresponds to one of said rotational axes, wherein the length adjustment assembly compensates for the change in distance between the first pivot bearing and the second bearing. Thus, the first and second pivot bearings are preferably each located at the interface of first and second linear actuator and column head. The end of the first linear actuator facing the column head is referred to as the upper end of the first linear actuator. The end of the second linear actuator facing the column head is referred to as the upper end of the second linear actuator. This development allows for realizing the pivoting of the column head relative to the linear actuators that occurs upon tilt adjustment by means of robust mechanical pivot elements having a simple structure. 
         [0022]    It is also particularly advantageous if the length adjustment assembly comprises a rod and an element having a orifice where one end of the rod can be inserted in and extracted from in order to change the distance between the first connecting area and the second connecting area upon an actuating motion of the first linear actuator and/or the second linear actuator. A patient support attachable to the column head is thereby pivotable about the rod&#39;s longitudinal axis. The element having a hole can be a bearing eye which is slidable on the rod wherein the bearing eye in particular surrounds or encloses the rod. In a particularly preferred embodiment, the rod system is not continuously formed between the two pivot bearings. 
         [0023]    In a particularly advantageous development of the invention, the column head has at least one support element which is fixedly connected to the part of the first bearing that is rotatable with respect to the first linear actuator, and which is pivotable about the first rotational axis so as to be pivoted about the first pivot bearing together with the head. The support element has at least one third connecting area for connecting the support element to a first end of a third linear actuator. Preferably, a second end of the third linear actuator opposite to the first end is operatively connected to the pivoting unit of the column head. 
         [0024]    The second end of the third linear actuator is preferably pivotable about an axis connecting the upper end of the first linear actuator and the upper end of the second linear actuator, or about an axis parallel to said axis. Upon extending or retracting the third linear actuator, and a swivel adjustment resulting therefrom, the second end of the third linear actuator moves on a circular path about the axis connecting the upper end of the first linear actuator and the upper end of the second linear actuator, or an axis parallel to said axis. 
         [0025]    By means of the development described above, both, tilt and swivel of a patient support connected to the column head can be adjusted easily and accurately. What is particularly regarded as an operative connection in this context, is the fact that a movement of the second end of the third linear actuator causes a related movement of the pivoting unit. 
         [0026]    As an alternative, or in addition, the support element may be pivotable about the first rotational axis of the first pivot bearing or about the second rotational axis of the second pivot bearing. 
         [0027]    Preferably, also the first end of the third linear actuator is pivotably connected with the third connecting area such that during an actuating motion of the third linear actuator, the longitudinal axis of the third linear actuator always lies in one plane, without simultaneous tilt adjustment of the column head. Therein, the third linear actuator is pivoted about a rotational axis which, when projected onto a horizontal plane, is orthogonal to the projection onto that plane of the rotation axis of the support element. 
         [0028]    As alternative to the pivotable connection between the first end of the third linear actuator and the support element, a second length adjustment assembly may be provided between support element and column head. 
         [0029]    The arrangement consisting of two vertical linear actuators for tilt and at least one linear actuator for swivel as described above allows in an advantageous manner for swiveling the column head without having to feed the driving means required therefore through the covering of the column basic body. Therefore, a complex covering, such as bellows, is not required, thus enabling easy cleaning of the operating table column. Further, the swivel function is decoupled from the tilt function. Correct tilt and swivel angle adjustment by the operator is thus possible in easy manner, and complex controlling and monitoring efforts can be avoided. 
         [0030]    It is particularly advantageous if the support element comprises a forth connecting area for connecting a first end of a fourth linear actuator, wherein the first end of the fourth linear actuator is operatively connected to the fourth connecting area, and a second end of the fourth linear actuator opposite to the first end of the fourth linear actuator is operatively connected to the pivoting unit. 
         [0031]    Preferably, the third connecting area of the support element and the first end of the third linear actuator are connected via a third pivot bearing. Further, the fourth connecting area of the support element and the first end of the fourth linear actuator are connected via a fourth pivot bearing. The rotational axes of the third and fourth pivot bearings are parallel. 
         [0032]    By means of this arrangement, an adjustment of the swivel of the column head at two points of action is made possible. Further, the third and fourth linear actuators can be single-acting hydraulic cylinders, thus allowing for a compact arrangement. Further, the third and second linear actuators have to meet lower stability requirements than in the case where only one actuator is provided. 
         [0033]    Alternatively, it is advantageous if the column head includes a second support element which is fixedly connected to the part of the second pivot bearing that is rotatable with respect to the second linear actuator such that it is pivoted about the second pivot bearing together with the head. The second support element includes a fourth connecting area for connecting a first end of the fourth linear actuator. Thus, the first end of the third linear actuator is connected to the support element, and the first end of the fourth linear actuator is connected to the second support element. Thereby, in case of high torque acting on the column head, parts of the torque are induced into both, the first linear actuator and the second linear actuator. Thus, additional stabilization of the column head and relief of the pivot bearing, as well as less load acting on the first and second linear actuators is achieved. 
         [0034]    It is particularly advantageous if the longitudinal axis of the first linear actuator and the longitudinal axis of the second linear actuator extend in a vertical plane, and if the third connecting area for connection with the lower first end of the third linear actuators is arranged on a first side at a first distance to said vertical plane, and the fourth connecting area for connection with the lower first end of the fourth linear actuator is arranged on a second side opposite to the first side at a second distance to said vertical plane. The first distance and the second distance are preferably equal. In this embodiment, it is advantageously possibly to form the third and/or fourth linear actuators as single-acting cylinders, and to thereby adjust the swivel of a patient support in a simple manner. 
         [0035]    It is further particularly advantageous if the third linear actuator and/or the fourth linear actuator are formed as single-acting cylinders, preferably as plunger cylinders. Thereby, a simple and cost-efficient structure is possible. 
         [0036]    Further, it as advantageous if the first linear actuator, the second actuator and/or the third actuator are formed as double-acting cylinders. In case of patients who are positioned such that their center of gravity no longer lies in the region between the first and second linear actuators, one of these cylinders is tensioned. Correspondingly, in case of patients which are positioned in transverse direction and whose center of gravity lies outside the region between the third and fourth linear actuator, one of these cylinders is tensioned. Thanks to the realization as double-acting cylinders, even the tensile forces acting in that case can be held by the corresponding cylinder. 
         [0037]    It is particularly advantageous if the operating table column is part of an operating table, and if a patient support can be attached to the column head. Further, it is advantageous if the operating table is realized as a stationary, a movable or a mobile operating table. By realizing of the operating table column as part of a full set, the typical requirements of a surgeon are met while stability of the total system is guaranteed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]    Further features and advantages of the invention result from the following description which in connection with the enclosed Figures explains the invention in more detail with reference to embodiments. 
           [0039]      FIG. 1  shows a schematic illustration of an operating table comprising an operating table column according to a first embodiment of the invention; 
           [0040]      FIG. 2  shows a detailed view of the operating table column according to  FIG. 1  including a basic body and a column head which has been pivoted for tilt adjustment about a horizontal axis extending orthogonally with respect to the longitudinal axis of patient support not shown, and pivoted for swing adjustment about an parallel axis with respect to the longitudinal axis of the patient support not shown; 
           [0041]      FIG. 3  is a detailed view of a part of the operating table column according to  FIG. 2  including the column head comprising a support element with a third and a fourth connecting area, wherein the column head has been pivoted about an axis parallel to the longitudinal axis of the patient support with respect to the neutral position shown in  FIG. 1 ; 
           [0042]      FIG. 4  is a detailed view of the operating table column according to  FIGS. 2 and 3 , wherein the column has been tilted in the opposite rotating direction with respect to  FIG. 2 ; 
           [0043]      FIG. 5  shows linear actuators of the operating table column according to  FIGS. 2 to 4 , for tilt and swivel adjustment; 
           [0044]      FIG. 6  shows the operating table column according to  FIGS. 2 to 5 , wherein height adjustment has been performed by simultaneous activation of the linear actuators serving for tilt adjustment; 
           [0045]      FIG. 7  is a detailed view of the operating table according to  FIGS. 1 to 6  without padding and add-on elements; and 
           [0046]      FIG. 8  shows linear actuators of an operating table column according to a second embodiment, wherein, in contrast to the first embodiment, only one linear actuator is provided for swivel adjustment. 
       
    
    
     DETAILED DESCRIPTION 
       [0047]      FIG. 1  is a schematic illustration of an operating table  100  according to a first embodiment of the invention, comprising a base  102 , an operating table column  10 , and a patient support  103 . 
         [0048]    The patient support  103  includes a plurality of components whose position relative to one another can be adjusted to allow for different positioning of patient not shown. In the present embodiment, the patient support  103  includes a seat panel  120 , a back panel  122 , a head panel  124 , a two-piece right leg panel  126 , and a two-piece left leg panel  128 . The longitudinal axis of the patient support is indicated by a dashed line and designated by reference sign Z. 
         [0049]      FIG. 2  is a detailed illustration of the operating table column  10  without the outer covering elements visible in  FIG. 1 . Elements having the same structure or same function are designated by identical reference numbers. The operating column  10  includes a basic body  12  and the column head  14  which has been pivoted for tilt adjustment about a horizontal axis extending orthogonally to the longitudinal axis of a patient support  103  not shown. Moreover, the column head  14  has been pivoted for swing adjustment about the rotational axis Z″. 
         [0050]    The basic body  12  is fixedly connected to the base  102  via a flange  29  provided on the lower side of the basic body  12 . The column head  14  is connected to drive and support elements of the seat panel  120  and the back panel  22  of the patient support  103 , either fixedly or so as to be slidable in longitudinal direction. In other embodiments, the column head  14  may be connected to the patient support  103  for coupling and de-coupling. 
         [0051]    A lifting carriage which is movable in vertical direction by means of a lifting cylinder  26  is provided for a first step of height adjustment. The lifting carriage comprises a lower part  62  and an upper part  80 . In other embodiments, another type of linear actuator may be provided instead of the lifting carriage, in particular a lead screw drive. A double-acting hydraulic cylinder with a vertically extending longitudinal axis is employed as the lifting cylinder  26 . When pressurized correspondingly, the piston rod  26   a  of the hydraulic cylinder  26  is pushed out of and into, respectively, the cylinder barrel  26   b  of the hydraulic cylinder. Therein, the lower part of the piston rod  26   a  is fixedly connected to the base  102  of the operating table  100 , preferably by means of a threaded connection. The lower end of the cylinder barrel  26   b  is fixedly connected to the lower part  62  of the lifting carriage, and the upper part of the cylinder barrel  26   b  is fixedly connected to the upper part  80  of the lifting carriage. A movement of the piston rod  26   a  relative to the cylinder barrel  26   b  causes a vertical movement of the cylinder barrel  26   b  together with the lifting carriage. The lifting carriage includes a guide bar  25  which fixedly couples the upper part  80  of the lifting carriage and the lower part  62  of the lifting carriage. The vertical movement of the lifting carriage is guided by the lifting cylinder  26  and the guide bar  24 . For this purpose, the guide bar  24  is fed through a guide bush (not shown in  FIG. 2 ) provided in the basic body  12 . The longitudinal axes of the cylinder barrel  26   b  and of the guide bar  24  are vertical, and thus parallel. By means of the arrangement of the lifting cylinder  26  and the guide bar  24  as well as the lifting carriage, the lifting carriage may be lowered as deep as into the region of the base  102  of the operating table  100 , i.e. even below the basic body  12 . In  FIG. 2 , the lifting carriage is shown in an upper end position. 
         [0052]    A lower first end of a cylinder barrel  20   b  of a first linear actuator  20  realized as hydraulic cylinder is fixedly connected to the lower part  62  of the lifting carriage. A lower first end of a cylinder barrel  22   b  of a second linear actuator  22  realized as a hydraulic cylinder is fixedly connected at a distance to the first end of the cylinder barrel  20   b . An upper second end of the cylinder barrel  20   b  is fixedly connected to the upper part  80  of the lifting carriage. An upper second end of the cylinder barrel  22   b  is fixedly connected at a distance to the second end of the cylinder barrel  20   b . Here, the upper and lower ends of the cylinder barrels  20   b ,  22   b  are fixedly clamped in the lifting carriage such that the position of the longitudinal axes of the linear actuators  20 ,  22  relative to the lifting carriage cannot be changed. The longitudinal axes of the linear actuators  20 ,  22  are vertically arranged at a mutual distance. The lower ends of the cylinder barrels  20   b ,  22   b  are on the same horizontal plane. The upper end of a piston rod  20   a  of the first linear actuator  20  is connected to the column head  14  in a first connecting area via a first pivot bearing  30 , and the upper end of a piston rod  22   a  of the second linear actuator  22  is connected to the column head  14  in a second connecting area via a second pivot bearing  32 . The first pivot bearing  30  defines a rotational axis A 1 , and the second pivot bearing  32  defines a rotational axis A 2 , with the rotational axes A 1 , A 2  being horizontal and parallel. The rotational axes A 1 , A 2  are orthogonal to a longitudinal axis Z′ which is parallel to the longitudinal axis Z of the patient support  103 . By means of the linear actuators  20 ,  22  tilt of the patient support  103  as well as height of the column head  14  can be changed, alternatively or additionally to the lifting carriage. 
         [0053]    The column head  14  comprises a pivoting and sliding pin  36  which is pivotable about the rotational axis A 2  relative to the second linear actuator  22  by means of the second pivot bearing  32 , wherein a first end of the pivoting and sliding pin  36  is fixedly connected to the second pivot bearing  32  via a retaining bush  37 . The column head  14  includes a pivoting unit  52  having a bearing bush  50  through which the second end of the pivoting and sliding pin  36  opposite the first end is fed, wherein the bearing bush  50  is free to move on the pivoting and sliding pin  36  in direction of the longitudinal axis thereof, i.e. in axial direction. Further, the bearing bush  50  is free to rotate about the pivoting and sliding pin  36 . By means of this arrangement, the pivoting unit  52  is rotatable about a rotational axis Z″ with respect to the pivot bearings  30 ,  32  and the linear actuators  20 ,  22 . 
         [0054]    The pivoting unit  52  serves for connecting the column head  14  with the patient support  103  and for pivoting the patient support  103  when it is connected to the pivoting unit  52 . The pivoting unit  52  is connected to the first pivot bearing  30  so as to be pivotable with respect to the first linear actuator  30  about the rotational axis A 1  of the first pivot bearing, and to be axially fixed. The pivoting and sliding pin  36  and the bearing bush  50  form a slide bearing which allows for both, rotation of the pivoting unit  52  about the pivoting and sliding pin  36  for swivel adjustment of the patient support  103  and length adjustment in case of non-parallel extension of the first linear actuator  20  and the second linear actuator  33 , such that pivoting and sliding pin  36  and bearing bush  50  are parts of a length adjustment assembly between the upper end of the first linear actuator  20  and the upper end of the second linear actuator  22 , said parts being movable with respect to one another. The first pivot bearing  30  and the second pivot bearing  32  are thus connected to one another via the pivoting and sliding pin  36  and the bearing bush  50 . 
         [0055]    For tilt adjustment of the pivoting unit  52 , the first linear actuator  20  has been extended, and the second linear actuator  22  has been kept in the retracted position. Doing so, the pivoting unit  52  was moved on the pivoting and sliding pin  36 , together with the bearing bush  50  such that the pivoting unit  52  has moved away from the second pivot bearing  32 . 
         [0056]    A support element  54  is fixedly connected to the first pivot bearing  30  so as to be pivoted about the rotational axis A 1  together with the column head  14 . The support element  54  is formed such that the lower end of the first arm has a third connecting area  56  ad the lower and of the second arm has a fourth connecting area  58 . The first arm of the support element  54  extends from the first pivot support  30  obliquely downward away from the vertical plane. The second arm of the support element  54  extends from the first pivot support  30  obliquely downward to the opposite side away from the vertical plane. 
         [0057]    The third connecting area  56  is located at a distance to the first side of a vertical plane including the longitudinal axes of the first linear actuator  20  and the second linear actuator  22 , and preferably the longitudinal axis Z′, and the fourth connecting area  58  is located at a distance to the second side of the above plane, with the distances having the same amount. 
         [0058]    The third connecting area  56  and the lower end of the third linear actuator  40  form a third pivot bearing  44 . The fourth connecting area  58  and the lower end of the fourth linear actuator, not shown in  FIG. 2 , form a fourth pivot bearing  46 . 
         [0059]    The third linear actuator  40  is pivotable about a rotational axis A 3  by means of the third pivot bearing  44 . The second upper end of the third linear actuator  40  that is formed by the upper end of the cylinder barrel  40   b  is connected to the pivoting unit  52  via a further pivot bearing so as to be pivotable about a rotational axis parallel to the third rotational axis A 3  such that the pivoting unit  52  is pivoted about the rotational axis Z″ when the third linear actuator  40  is activated. In this first embodiment, the third linear actuator  40  is formed as a single-acting hydraulic cylinder which is arranged such that upon pressurization, the piston rod  40   a  is actively pushed out of the cylinder barrel  40   b . Thus, the pivoting unit  52  is rotated in a first direction about the rotational axis Z″ when the third linear actuator  40  is pressurized. 
         [0060]    By means of the fourth pivot bearing  46 , the fourth linear actuator is pivotable about a fourth rotational axis A 4  which is parallel to the rotational axis A 3  and to the vertical plane. The second upper end of the fourth linear actuator that is formed by the upper end of the cylinder barrel is connected to the pivoting unit  52  via a further pivot bearing so as to be pivotable about a rotational axis parallel to the fourth rotational axis A 4  such that the pivoting unit  52  is pivoted about the rotational axis Z″ when the fourth linear actuator is activated. In the first embodiment, the fourth linear actuator, too, is formed as a single-acting hydraulic cylinder arranged such that upon pressurization, the piston rod thereof is actively pushed out of the cylinder barrel. Thereby, the pivoting unit  52  is rotted in a second direction, opposite the first direction, about the rotational axis Z″ when the fourth linear actuator is pressurized. For swing adjustment, the third linear actuator  40  was extended, and the fourth linear actuator was compressed such that the pivoting unit  52  was rotated about the rotational axis Z″ in a direction away from the observer. 
         [0061]      FIG. 3  shows a detailed view of the column head  14  shown in  FIG. 2  from another point of view. The pivoting unit  52  is tilted like in  FIG. 2  as compared to a horizontal neutral position where at least the resting surface of the seat panel  120  connected to the pivoting unit  52  is positioned horizontally, i.e. is neither tilted nor swung. For this purpose, starting from the neutral position, the first linear actuator  20  has been extended, and the second linear actuator  22  has been kept in its lower end position. Moreover, the pivoting unit  52  has been pivoted from the swing end position shown in  FIG. 2  to the opposite end position, i.e. counter-clockwise from the perspective shown in  FIG. 3 . For this purpose, the fourth linear actuator  42  has been extended, and the third linear actuator  40  has been compressed to the retracted position. To this aim, corresponding hydraulic valves are opened when the fourth linear actuator  42  is extended in order to discharge hydraulic fluid from the third linear actuator  40 . 
         [0062]    By means of subsequent extension of the third linear actuator  40 , the pivoting unit  52  is pivoted from the position shown in  FIG. 3  in counter-clockwise direction about the rotational axis Z″, wherein the fourth linear actuator  42  is compressed. To this aim, corresponding hydraulic valves are opened when the third linear actuator  40  is extended, such that hydraulic fluid may be discharged from the fourth linear actuator  42 . Thereby, swivel of the patient support  103  can be adjusted easily and independent on the tilt adjustment. Further, the piston rod of the fourth linear actuator  42  is designated by reference sign  42   a , and the cylinder barrel of the fourth linear actuator  42  is designated by reference sing  42   b.    
         [0063]    Further, the connection of the first linear actuator  20  to the pivoting unit  52  and the support element  54  via the first pivot bearing  30  is clearly visible in  FIG. 3 . By means of extending the first linear actuator  20 , the pivoting unit  52  has been tilted, together with the support element  54 , about a rotational axis perpendicular to the rotational axis Z′, or about a rotational axis parallel to the rotational axis Z′. 
         [0064]      FIG. 4  shows a detailed illustration of the operating table column  10  according to  FIGS. 2 and 3  wherein the column head  14  has been tilted in the opposite direction with respect to  FIG. 2 . 
         [0065]    In this  FIG. 4 , the second linear actuator  22  of the operating table column  10  has been extended farther as compared to  FIGS. 2 and 3 . The first linear actuator  20  is retracted. Thereby, the pivoting unit  52  is tilted in a direction different from that shown in  FIGS. 2 and 3 . 
         [0066]    Further, the pivot bearing  48  which pivotably connects the upper end of the third linear actuator  40  to the pivoting unit  52  is clearly visible in  FIG. 4 . Therein, the rotational axis of the pivot bearing  48  is parallel to the longitudinal axis Z′ and to the rotational axis A 3 . 
         [0067]      FIG. 5  shows linear actuators  20 ,  22 ,  40 ,  42  of the operating table column  10  according to  FIGS. 2 and 4  for tilt and swing adjustment. These are the main elements which enable height adjustment, tilt and swing of the patient support  103  of the operating table  100 . What is shown is the first linear actuator  20  which is connected to the pivoting unit  52 , not shown in  FIG. 5 , via the first pivot bearing  30  and a pin  38 . Further visible are the upper ends of the third linear actuator  40  and the fourth linear actuator  42  which are connected to the pivoting unit  52  not shown. The second linear actuator  22  is connected to the pivoting and sliding pin  36  via the second pivot bearing  32  and the retaining bush  37 . 
         [0068]    The pivoting and sliding pin  36  and the pin  38  are oriented along the longitudinal axis Z″ and allow for rotation of the pivoting unit  52 , not shown, about said longitudinal axis Z″ for adjustment of swing of the patient support  103 . 
         [0069]    At the lower end of the third connecting are 56, there is provided a pin which is held on both sides in the third connecting area  56  and whose longitudinal axis is parallel to the longitudinal axis Z′. The pin allows for pivoting the third linear actuator  40  about the rotational axis A 3 . Together with the third connecting area  56  and the lower end of the third linear actuator  40 , the pin forms the third pivot bearing  44 . 
         [0070]    At the upper end of the third linear actuator  40  there is provided a first pin seat  41  adapted to accommodate a pin for connection of the upper end of the third linear actuator  40  and the pivoting unit  52 , and which thus enables pivoting of the third linear actuator  40  relative to the pivoting unit  52  about an axis parallel to the longitudinal axis Z′. 
         [0071]    At the lower end of the fourth connecting area  58  there is provided a pin which is held on both sides in the fourth connecting area  58  and whose longitudinal axis is parallel to the longitudinal axis Z′. The pin allows for pivoting of the fourth linear actuator  42  about the rotational axis A 4 . Together with the fourth connecting area  58  and the lower end of the fourth linear actuator  42 , the pin forms the fourth pivot bearing  46 . 
         [0072]    At the upper end of the fourth linear actuator  42  there is provided a second pin seat  43  which is adapted to accommodate a pin for connecting the upper end of the fourth linear actuator  42  and the pivoting unit  52 , and which thus enables pivoting of the fourth linear actuator  42  relative to the pivoting unit  52  about an axis parallel to the longitudinal axis Z′. 
         [0073]    In contrast to  FIG. 4 , the fourth linear actuator  42  has been extended in  FIG. 5 , whereas the third linear actuator  40  has been retracted. 
         [0074]      FIG. 6  shows the operating table column  10  according to  FIGS. 2 to 5  wherein height adjustment has been performed by simultaneously activating the linear actuators  20  and  22  serving for tilt adjustment. Further, the third linear actuator  40  is extended and the fourth linear actuator  42  is retracted, whereby corresponding swing of the patient support  103  connected to the pivoting unit  52  is achieved. 
         [0075]      FIG. 7  is a detailed illustration of the operating table  100  according to  FIGS. 1 to 6  without padding and add-on elements wherein the outer covering elements of the operating table  10  and the base  102  are illustrated. Further, the third connecting area  56  and the fourth connecting area  58  of the support element  54 , as well as the third pivot bearing  44  and the fourth pivot bearing  46  are visible. 
         [0076]    A first patient support arm  104  and a second patient support arm  106  are connected to the pivoting unit  52  on two opposite sides. The first patient support arm  104  includes a first segment  108  for supporting the back panel  122  and a second segment  110  for supporting the seat panel  120  of the patient support  103 . Likewise, the second patient support arm  106  includes a first segment  112  for supporting the back panel  122  and a second segment  114  for supporting the seat panel  120  of the patient support  103 . 
         [0077]    Via the patient support arms  104  and  106 , the back panel  122  and the seat panel  122  are arranged so as to be pivotable with respect to one another about a rotational axis orthogonal to the longitudinal axis Z of the patient support  103 . For this purpose, a first pivot cylinder  116  is arranged in the first segment  108  of the first patient support arm  104  so as to be capable of pivoting the second segment  110  of the first patient support arm  104  relative to the first segment  108 . Further, a second pivot cylinder  118  is arranged in the first segment  112  of the second patient support arm  106  so as to be capable of pivoting the second segment  114  of the second patient support arm  106  relative to the first segment  112 . Further, the patient support  103  is arranged so as to be slidable along the longitudinal axis Z thereof with respect to the operating table column  10 . 
         [0078]    In  FIG. 8 , linear actuators  20 ,  22 ,  134  of an operating table column  130  are shown, according to a second embodiment which, in contrast to the operating table column  10  of the first embodiment, includes a support element  132  comprising only one arm instead of the support element  54 . Otherwise, the structure, function and coupling of the support element  132  correspond to structure, function and coupling of the support element  54 . Further, instead of the third and fourth linear actuators  40 ,  42  only one linear actuator  134  is provided which is formed as a double-acting cylinder and whose lower end is connected to the arm of the support element  132  like the third linear actuator  40 , and whose upper end is connected to the pivoting unit  52 . 
         [0079]    Structure and function of the remaining elements of the operating table column  130  correspond to the operating table column  10  of the first embodiment. 
         [0080]    The embodiments of the invention described above are provided by way of example only. The skilled person will be aware of many modifications, changes and substitutions that could be made without departing from the scope of the present invention. The claims of the present invention are intended to cover all such modifications, changes and substitutions as fall within the spirit and scope of the invention.