Patent Publication Number: US-6212713-B1

Title: Examination table with sliding back section

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to articulated examination tables and, more particularly, to an articulated examination table for positioning a patient between a supine position and a generally upright sitting position. 
     Articulated examination tables are well known in the prior art, and provide for positioning of a patient to a variety of different positions which may be selected in accordance with the particular procedure being performed and with reference to the preferences of the particular operator or surgeon. In particular, it is known to provide a seat section for supporting a patient and a pivoted back section movable relative to the seat section to position the upper torso of a patient at a desired orientation relative to the horizontal wherein the back section may be actuated for movement by an electrical or hydraulic actuator. 
     A recognized problem associated with tables having pivoted back sections is shear movement between the back section of the table and the patient&#39;s back as the back section is pivoted. This typically requires that the patient reposition his or her back along the back section during the pivotal movement in order to accommodate the relative movement between the table surface and the patient. 
     U.S. Pat. No. 5,790,997 to Ruehl discloses a table having an articulated deck wherein articulation of the deck includes movement of the deck sections relative to each other to match the expansion and contraction of the skin of a person supported on the deck. This device requires that the movement of the deck sections relative to each other coincide with a vertical movement of the articulated deck, such that movement of the deck sections relative to each other independent of the vertical movement is not accommodated. 
     Accordingly, there is a continuing need for an examination table capable of comfortably supporting a patient during pivotal movement of a table back section relative to a table seat section. Further, there is a need for such a table incorporating a simple mechanism for providing relative movement between a table back and seat section during pivotal movement of the back section. 
     SUMMARY OF THE INVENTION 
     The present invention provides an examination table including a base member, a seat section supported on the base member, and a back section including an elongated pivot frame and a sliding frame slidably supported on the pivot frame. A hinge connection connects the pivot frame to the seat section for movement of the back section from a substantially horizontal position, parallel to the seat section, to an inclined position. 
     A coupling member is supported on the pivot frame and includes a first portion connected to the sliding frame and a second portion connected to the seat section. The coupling member is supported for rotational movement about a pivot point on the pivot frame. Pivotal movement of the back section about the hinge connection causes rotation of the coupling member relative to the pivot frame, and thereby causes the sliding frame to move longitudinally along the pivot frame. 
     More particularly, the first and second portions of the coupling member define spaced members extending radially outwardly from the pivot point, and the first portion comprises a telescoping member extending between the pivot point and the sliding frame. One end of an elongated linkage rod is connected to a distal or radially outer end of the second portion and an opposite end of the linkage rod is connected to the seat section. Thus, the linkage rod operates as an anchoring structure extending to the coupling member to cause the rotational movement of the coupling member during movement of the back section. 
     The back section is actuated for movement by a linear actuator located within the seat section wherein the linear actuator extends between the seat section and the pivot frame for the back section. Actuation of the linear actuator causes pivotal movement of the back section relative to the seat section and simultaneous movement of the sliding frame relative to the pivot frame. In addition, a pair of arm rests are supported on the coupling member and are actuated for rotational movement about the pivot point of the coupling member at the same time that the back section is actuated for pivotal movement whereby the arm rests are maintained in a substantially horizontal orientation throughout movement of the back section. 
     Therefore, it is an object of the present invention to provide an examination table which accommodates the longitudinal movement of a patient&#39;s back during pivotal movement of a back section of the table relative to a seat section. 
     It is another object of the invention to provide an examination table which includes a back section pivotal relative to a seat section and including a sliding member on the back section for longitudinal movement relative to a pivoted frame of the back section. 
     Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the examination table of the present invention configured to support a patient in a supine position; 
     FIG. 2 is a perspective view of the examination table configured to support a patient with the back in a partially inclined position; 
     FIG. 3 is a perspective view of the examination table configured to support a patient with the back in an upright position; 
     FIG. 4 is a perspective, partially cut away view showing the seat section and a portion of the back section; 
     FIG. 5 is a side elevational view in partial cross-section illustrating the examination table in the position illustrated in FIG. 1; 
     FIG. 6 is a side elevational view in partial cross-section illustrating the examination table in the position shown in FIG. 2; and 
     FIG. 7 is a side elevational view in partial cross-section illustrating the examination table in the position shown in FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to FIGS. 1-3, the examination table  10  of the present invention includes a base member  12  defining an upwardly extending pedestal structure for supporting the examination table  10  on a floor surface. The base member  12  supports a frame  14  for a seat section  16 . The frame  14  supports a pivot frame  18  for a back section  20 , and further supports a leg section  24 . The seat section  16 , back section  20  and leg section  24  define a patient support surface for the examination table  10 . In addition, the back section  20  supports a head rest  26  extending above the back section  20  for supporting a patient&#39;s head, and a pair of arm rests  28 ,  30  are also supported on the back section  20  and located to either side thereof extending toward the sides of the seat section  16 . 
     Referring to FIG. 4, the connection between the seat section  16  and the back section  20  is illustrated with the seat section and back section cushions removed to expose the respective seat and back section frames  14 ,  18 . The frame  14  includes a pair of hinge connection extensions  32  and  34 , and the frame  18  includes a pair of pivot extensions  36  and  38  rigidly attached to the frame  18  and connected to the hinge connection extensions  32 ,  34  by means of respective pivot pins  40  and  42 . The pins  40 ,  42  support the back section  20  for pivotal movement through the frame  18  such that the frame  18  comprises a pivot frame for the back section  20 . The frame  18  is driven in pivotal movement by a linear actuator  44 , such as an actuator powered by an electric motor  43 , which extends between a mounting point  45  on the seat frame  14  and a drive extension  46  rigidly attached to the pivot frame  18  at junction member  47  (see also FIG.  5 ). Extension of the linear actuator  44  causes the pivot frame  18  to pivot upwardly toward an upright sitting position for the back section  20 . 
     A sliding frame  48  is supported on an upper portion of the pivot frame  18  for longitudinal sliding movement relative to the pivot frame  18 . The pivot frame  18  includes a pair of side walls  50 ,  52 , each with an out turned flange  54 ,  55 . The outer edges  56 ,  57  of the sliding frame  48  extend around the out turned flanges  54 ,  55  for guiding the sliding frame  48  in longitudinal sliding movement along the pivot frame  18 . 
     The sliding frame  48  is actuated for sliding movement by a coupling member  58  comprising a rotatable shaft  60  supported in bearings  62 ,  64  associated with the side walls  50 ,  52 , respectively. A pair of telescoping members  66 ,  68 , defining first portions of the coupling member  58  are mounted to the shaft  60  for rotation therewith. Each of the telescoping members  66 ,  68  comprises an outer tubular member  70  and an inner slide member  72  which is freely slidable within the outer tubular member  70 . The ends of the inner slide members  72  distal from the shaft  60  are attached to the sliding frame  48  at connections  74 ,  76  which permit rotation of the telescoping members  66 ,  68  relative to the slide frame  48 . 
     The coupling member  58  further includes a second portion  78  formed by an elongated arm attached to the shaft  60  for rotation therewith wherein the second portion  78  is circumferentially spaced from the telescoping members  66  and  68 , and an end of the second portion  78  distal from the rotatable shaft  60  is attached to a linkage rod  80  which extends to a hinged connection point  82  on the seat frame  14 . 
     Referring to FIGS. 5-7, alternative positions of the back section  20  relative to the seat section  16  are shown to illustrate the operation of the coupling member to move the sliding frame  48  relative to the pivot frame  18 . In particular, FIG. 5 illustrates the back section  20  in a substantially horizontal position parallel to the seat section for supporting a patient in a supine position. In this position, the telescoping members  66 ,  68  are angled toward the seat section  16  as a result of the linkage rod  80  biasing the second portion  78  of the coupling member  58  forwardly toward the head end of the back section  20 . It can be seen that the inner members  72  of the telescoping members  66 ,  68  are extended outwardly from the outer member  70  to position the sliding frame  48  such that a lower edge  84  thereof is positioned closely adjacent to the seat section  16 . 
     FIG. 6 shows the back section  20  in a partially inclined position. It can be seen that the linkage rod  80  has caused the second portion  78  of the coupling member  58  to pivot in a direction toward the seat section  16  such that the sliding frame  48  is caused to move upwardly along the pivot frame  18 . In this position, the inner member  72  of the telescoping members  66 ,  68  is fully retracted within the outer member  70 . 
     FIG. 7 illustrates the back section  20  in a fully upright position to define a sitting position with examination table  10 . In this position, the linear actuator  44  is fully extended, and the coupling member  58  is rotated to orient the telescoping members  66 ,  68  at an angle extending toward the head end of the back section  20  with the inner members  72  extending from the outer members  70  to accommodate the upward movement of the sliding frame  48  relative to the pivot frame  18 . Thus, as the back section  20  is pivoted upwardly, the sliding frame  48  concurrently moves upwardly to accommodate movement of a patient&#39;s back relative to the pivot frame  18 . 
     It should also be noted that the frame  14  for the seat section  16  is attached to an extension  86  of the base member  12  at a pivot point  88 , and a linear actuator  90  extends through the base  12  to a hinge point  92  with the seat frame  14 . Thus, the actuator  90  may be operated to pivot the seat section  16  upwardly about the pivot connection  88  to provide a desired reclined orientation for the patient support surface of the examination table  10 . In addition, an actuator  94  (FIG. 4) is also provided in the preferred embodiment to actuate the leg section  24  in pivotal movement relative to the seat section  16 . 
     Referring further to FIGS. 1-4, the arm rests  28 ,  30  are mounted to support members  96 ,  98 , respectively, which extend to mounting points at either end of the rotatable shaft  60 , such as at the end adjacent bearing  62  in FIG.  4 . Thus, the support members  96 ,  98  and associated arm rests  28 ,  30  pivot relative to the back section  20  as the back section  20  pivots relative to the seat section  16 . The pivotal movement of the support members  96 ,  98  enables the arm rests  28 ,  30  to remain substantially horizontal, parallel to the seat section  16 , and to move vertically in movement corresponding to that of a patient supported on the table  10  throughout movement of the back section  20 . 
     While the form of apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.