Patent Publication Number: US-11644624-B2

Title: Separable infinite rotation fiber optic and slip ring rotary joint for suspension arm

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/877,306, filed May 18, 2020 (now U.S. Publication No. 2021-0003785-A1), which is a continuation of U.S. patent application Ser. No. 15/645,081 (now U.S. Pat. No. 10,656,341 issued May 19, 2020), filed Jul. 10, 2017, which claims the benefit of U.S. Provisional Application No. 62/361,301, filed Jul. 12, 2016, the entire contents of each of which are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a joint, and in particular to a separable infinite rotation fiber optic and slip ring joint that can be used in medical devices. 
     BACKGROUND OF THE INVENTION 
     Surgical monitors have been used in operating rooms to provide images to surgeons in the room. Likewise, other wired devices, such as surgical lights, speakers, joysticks, keyboards and cameras, have been used in operating rooms to provide surgical information to a surgeon or other person in the operating room (e.g., images from a camera or patient vital information). Such devices receive and/or provide signals and power to and/or from various supports mounted or provided in the operating room, thereby requiring wiring to extend through supports for such devices to the devices. Such wiring arrangements have necessitated that the rotation of joints of the supports be limited (e.g., using stops to limit rotation) to allow the wiring to extend fully through the supports without subjecting the wiring to excessive and damaging twisting of the wiring. Alternatively, if the rotation of the joints allowed for a larger range of rotation, such arrangements do not allow for a large data transfer rate through the supports to the devices. Thus, there is a need for accommodating wiring in a way which will allow for a large data transfer rate while simultaneously allowing the supports to be fully and easily adjustable. 
     SUMMARY OF THE INVENTION 
     The present invention, according to one aspect, is directed to a medical suspension arm assembly including a plurality of suspension arms, with each adjacent pair of the suspension arms being connected to each other by a joint and with at least one of the joints comprising an infinite rotation joint. The infinite rotation joint allows the suspension arms at the infinite rotation joint to have unlimited rotation relative to one another. Cabling including at least one fiber optic cable extends through each of the suspension arms and each joint. A wired medical unit is connected to an end of the plurality of suspension arms. High definition video, data and power can be transferred along each one of the suspension arms through the cabling and across each joint. The infinite rotation joint can be separable and can automatically form a unit when adjacent arms are connected together. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One or more embodiments of the present invention are illustrated by way of example and should not be construed as being limited to the specific embodiments depicted in the accompanying drawings, in which like reference numerals indicate similar elements. 
         FIG.  1    illustrates a perspective view of a suspension arm assembly according to the present invention. 
         FIG.  2    is a side view of the suspension arm assembly according to the present invention. 
         FIG.  3    is an exploded side view of the suspension arm assembly according to the present invention. 
         FIG.  4    is a cross-sectional view of the suspension arm assembly according to the present invention. 
         FIG.  5    is an enlarged cross-sectional view of a first infinite rotation joint of the suspension arm assembly according to the present invention taken from the circle V of  FIG.  4   . 
         FIG.  6    is an enlarged cross-sectional view of a second infinite rotation joint of the suspension arm assembly according to the present invention taken from the circle VI of  FIG.  4   . 
         FIG.  7    is an enlarged cross-sectional view of a third infinite rotation joint of the suspension arm assembly according to the present invention taken from the circle VII of  FIG.  4   . 
         FIG.  8    is a schematic view of the data and power communications across an infinite rotation fiber optic and slip ring rotary joint according to the present invention. 
         FIG.  9 A  is a partial cross-sectional side view of a infinite rotation fiber optic and slip ring rotary joint according to the present invention. 
         FIG.  9 B  is a first end view of the infinite rotation fiber optic and slip ring rotary joint according to the present invention. 
         FIG.  9 C  is a second end view of the infinite rotation fiber optic and slip ring rotary joint according to the present invention. 
         FIG.  10    is an enlarged cross-sectional view of a first area of the infinite rotation fiber optic and slip ring rotary joint according to the present invention taken from the circle X of  FIG.  9 A . 
         FIG.  11    is an enlarged cross-sectional view of a second area of the infinite rotation fiber optic and slip ring rotary joint according to the present invention taken from the circle XI of  FIG.  9 A . 
         FIG.  12    a schematic view of the data communications across a fiber optic rotary joint using a multiplexer according to the present invention. 
         FIG.  13    is an exploded side view of the suspension arm assembly having separable infinite rotation fiber optic and slip ring joints according to the present invention. 
         FIG.  14    is a perspective view of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  15    is a side view of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  16    is a cross-sectional view of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  17    is a cross-sectional view of the separable infinite rotation fiber optic and slip ring joint according to the present invention with a first optical connector and a second optical connector removed. 
         FIG.  18    is an exploded perspective view of a main rotor of a rotor and a stator of the separable infinite rotation fiber optic and slip ring joint according to the present invention and with the first optical connector and the second optical connector removed. 
         FIG.  19    is an end view of the main rotor of the rotor of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  20    is an exploded side view of the stator of the separable infinite rotation fiber optic and slip ring joint according to the present invention with the first optical connector removed. 
         FIG.  21    is a perspective view of an inner housing of the stator of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  22    is a perspective view of an outer housing of the stator of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  23    is a perspective end view of the stator of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  24    is an end view of the stator of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  25    is a side view of a data leaf spring contact of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  26    is an exploded view of the main rotor of the rotor, the stator and the first optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  27    is a side view of the first optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  28    is a cross-sectional view of the first optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention taken along the line XXVIII-XXVIII of  FIG.  27   . 
         FIG.  29    is a partial perspective cross-sectional view of the first optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  30    is a side view of a rotor connector of the rotor and the second optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  31    is an exploded perspective view of the rotor connector of the rotor and the second optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  32    is an end view of the rotor connector of the rotor and the second optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  33    is a side view of the second optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
         FIG.  34    is a cross-sectional view of the second optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention taken along the line XXXIV-XXXIV of  FIG.  33   . 
         FIG.  35    is a perspective view of the second optical connector of the separable infinite rotation fiber optic and slip ring joint according to the present invention with the clip sleeve removed. 
         FIG.  36    is a close-up cross-sectional view of the separable infinite rotation fiber optic and slip ring joint according to the present invention. 
     
    
    
     The specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting. 
     DETAILED DESCRIPTION 
     The reference number  10  ( FIGS.  1 - 4   ) generally designates a suspension arm assembly of the present invention. The suspension arm assembly  10  includes a ceiling attachment member  24 , a wired medical unit  16  and a plurality of arms  12  between the ceiling attachment member  24  and the wired medical unit  16 . The intersections between one of the arms  12  and the ceiling attachment member  24 , each of the arms  12 , and one of the arms  12  and the wired medical unit  16  allow for infinite rotation. Each intersection also includes an infinite rotation fiber optic and slip ring joint  14  (see  FIGS.  3  and  4   ) therein. A cabling system  22  transmits data and power through the suspension arm assembly  10  to the wired medical unit  16  and the infinite rotation fiber optic and slip ring joints  14  allow for unlimited rotation of the arms  12  and the wired medical unit  16 . 
     The illustrated suspension arm assembly  10  is configured to be positioned within a room (e.g., an operating room) and, in the illustrated embodiment, includes the wired medical unit  16 , which is configured to provide information to the medical personnel in the room and/or to assist the medical personnel in the room perform various functions. In the illustrated example, the wired medical unit  16  includes a display support assembly  18  at a distal end of one of the arms  12  for supporting a display monitor  20  for providing surgical information to a surgeon or other person in the operating room (e.g., images from a camera (e.g., an in-light camera or an endoscopic camera) or patient vital information). It is contemplated that other items (e.g., surgical lights, dual displays, cameras, microphones, etc.) in addition to or instead of the display monitor  20  can be located at the end of the suspension arm assembly  10  such that the data stream can be from or to the item at the end of the suspension arm assembly. 
     In the illustrated example, the suspension arm assembly  10  is connected to a ceiling and supports the wired medical unit  16  above a support surface, such as a floor. The suspension arm assembly  10  includes the ceiling attachment member  24 , a first one of the arms  12  in the form of an extension arm  26  connected to the ceiling attachment member  24  at a first infinite rotation joint  28 , a second one of the arms  12  in the form of a load counterbalancing spring arm  30  connected to the extension arm  26  by a second infinite rotation joint  32 , and the display support assembly  18  connected to the load counterbalancing spring arm  30  with a third infinite rotation joint  34 . While the suspension arm assembly  10  is illustrated as having two arms  12 , it is contemplated that the suspension arm assembly  10  could have any number of arms  12  (including only one arm  12 ). Furthermore, while particular configurations of infinite rotation joints having the infinite rotation fiber optic and slip ring joint  14  are described below, it is contemplated that any configuration of infinite rotation joints having the infinite rotation fiber optic and slip ring joint  14  therein could be used. Moreover, while the suspension arm assembly  10  includes the ceiling attachment member  24  for connecting the suspension arm assembly  10  to a ceiling, it is contemplated that the ceiling attachment member  24  could be used to connect the suspension arm assembly  10  to any structure (fixed or movable) above a support surface, such as a floor. 
     The illustrated ceiling attachment member  24  accepts the cabling system  22  therein and supports the suspension arm assembly  10  from the ceiling of a room. The ceiling attachment member  24  includes a ceiling attachment flange  36  and a down tube  38 . The ceiling attachment flange  36  can have any configuration for connecting to a ceiling support structure. In the illustrated embodiment, the ceiling attachment flange  36  is a flat circular disc  40  having a plurality of holes  42  therein configured to receive fasteners (not shown) for fixedly connecting the flat circular disc  40  to the ceiling support structure. The flat circular disc  40  includes a central opening  44  receiving a first section  46  of the cabling system  22  therethrough. The down tube  38  includes a down cylinder  48  being co-axial with the central opening  44  in the flat circular disc  40  of the ceiling attachment flange  36 . The down tube  38  can have any axial length to adjust for various heights of ceilings in the room. The ceiling attachment member  24  further includes a central axis spindle  50  for connecting the down tube  38  to the extension arm  26 . 
     In the illustrated example, the central axis spindle  50  allows for infinite rotation of the extension arm  26  about the ceiling attachment member  24  and houses one of the infinite rotation fiber optic and slip ring joints  14  therein connecting the first section  46  of the cabling system  22  to a second section  52  of the cabling system  22 . The central axis spindle  50  includes an axis cylinder  54  having a pair of down tube mounting flanges  56  including an upper disc  58  and a lower disc  60 . The upper disc  58  surrounds a top edge of the axis cylinder  54  and the lower disc  60  surrounds a central area of the axis cylinder  54 . The upper disc  58  and the lower disc  60  have the same outer diameter corresponding to the inner diameter of the down cylinder  48  of the down tube  38  and have outer surfaces  62  which are aligned with one another such that the upper disc  58  and the lower disc  60  abut against an inner surface  64  of the down cylinder  48  of the down tube  38  (see  FIG.  5   ). Fasteners (not shown) extend through aligned openings  74  in the down cylinder  48  and into openings  76  in the outer alignment surfaces  62  of the upper disc  58  and the lower disc  60  to fixedly connect the down cylinder  48  to the central axis spindle  50 . As illustrated in  FIG.  5   , the lower disc  60  closes a bottom open end  78  of the down cylinder  48 . An outer surface  66  of the axis cylinder  54  includes an upper bearing receiving area  68  located directly below the lower disc  60  and a lower bearing receiving area  70  located adjacent but spaced from a bottom edge  72  of the axis cylinder  54 . The axis cylinder  54  also includes a bearing receiving surface below the lower bearing receiving area  70 . The axis cylinder  54  receives the infinite rotation fiber optic and slip ring joint  14  therein and is received in a proximal end  80  of the extension arm  26 . 
     The illustrated extension arm  26  is connected to the ceiling attachment member  24  at the first infinite rotation joint  28 . The extension arm  26  includes a hollow tube  82  having the proximal end  80  connected to the ceiling attachment member  24  at the first infinite rotation joint  28  and a distal end  84  connected to the load counterbalancing spring arm  30  at the second infinite rotation joint  32 . As illustrated in  FIG.  5   , the proximal end  80  of the extension arm  26  includes a spindle receiving block  86  receiving the central axis spindle  50  therein. The spindle receiving block  86  includes a side tube receiving counterbore  88  in a side face  96  thereof receiving an end of the hollow tube  82  therein for fixedly connecting the hollow tube  82  to the spindle receiving block  86 . The spindle receiving block  86  further includes a central spindle receiving circular hole  90  that extends through the spindle receiving block  86  from a top surface  92  to a bottom surface  94  thereof. An upper bearing ring receiving counter bore  98  in the top surface  92  of the spindle receiving block  86  surrounds the central spindle receiving circular hole  90  to form a top step surface  100  located below the top surface  92 . Likewise, a lower bearing ring receiving counter bore  102  in the bottom surface  94  of the spindle receiving block  86  surrounds the central spindle receiving circular hole  90  to form a bottom step surface  103  located above the bottom surface  94 . In the illustrated example, the spindle receiving block  86  has a circular cross-section. However, it is contemplated that the spindle receiving block  86  could have any exterior shape. 
     In the illustrated example, the central axis spindle  50  is inserted into the spindle receiving block  86  of the extension arm  26  to allow the extension arm  26  to rotate about the axis cylinder  54  of the central axis spindle  50 . During assembly of the suspension arm assembly  10 , one of the infinite rotation fiber optic and slip ring joints  14  is connected to the first section  46  of the cabling system  22  (as discussed in more detail below) and inserted into an interior  104  of the axis cylinder  54  through the bottom edge  72  of the axis cylinder  54 . A stator  106  of the infinite rotation fiber optic and slip ring joint  14  is then fixed to the axis cylinder  54  by fasteners (or any other connection method) such that the stator  106  of the infinite rotation fiber optic and slip ring joint  14  at the first infinite rotation joint  28  remains stationary relative to the room. 
     As illustrated in  FIGS.  2  and  5   , a first bearing ring  108  and a second bearing ring  110  allow the extension arm  26  to rotate relative to the ceiling attachment member  24  about a first vertical axis  129 . The first bearing ring  108  surrounds the axis cylinder  54  at the upper bearing receiving area  68 , with the lower disc  60  of the central axis spindle  50  resting on the first bearing ring  108 . The first bearing ring  108  is located within the upper bearing ring receiving counter bore  98  in the top surface  92  of the spindle receiving block  86  and rides on the top step surface  100 . The second bearing ring  110  surrounds the axis cylinder  54  at the lower bearing receiving area  70 . The second bearing ring  110  is located within the lower bearing ring receiving counter bore  102  in the bottom surface  94  of the spindle receiving block  86 , with the bottom step  103  resting on the second bearing ring  110 . A disc shaped spanner nut  112  is connected to an end of the axis cylinder  54  (e.g., by being threaded onto the axis cylinder  54 ) to hold the second bearing ring  110  on the end of the axis cylinder  54 . The disc shaped spanner nut  112  also compresses the second bearing ring  110  between the bottom step  103  of the lower bearing ring receiving counter bore  102  and the disc shaped spanner nut  112  such that the second bearing ring  110  rides on the disc shaped spanner nut  112 . The disc shaped spanner nut  112  thereby ensures that the extension arm  26  is securely connected to the ceiling attachment member  24  to allow the extension arm  26  to rotate about the ceiling attachment member  24  in a stable manner. 
     In the illustrated example, a rotor  114  of the infinite rotation fiber optic and slip ring joint  14  is allowed to rotate relative to the stator  106  of the infinite rotation fiber optic and slip ring joint  14  and is connected to the second section  52  of the cabling system  22 . Therefore, the rotor  114  of the infinite rotation fiber optic and slip ring joint  14  at the first infinite rotation joint  28  and the second section  52  of the cabling system  22  are able to rotate with rotation of the extension arm  26  about the ceiling attachment member  24 . As illustrated in  FIG.  5   , the second section  52  of the cabling system  22  enters the hollow tube  82  of the extension arm  26  through a cabling entrance  116  in the hollow tube  82  adjacent the spindle receiving block  86  at the proximal end  80  of the extension arm  26 . A cosmetic and protective cover  118  covers a bottom of the proximal end  80  of the extension arm  26 , with the cosmetic and protective cover  118  being connected to a bottom of the hollow tube  82  in order to cover the cabling entrance  116  and also being connected to a bottom of the spindle receiving block  86  to protect a bottom of the spindle receiving block  86 , the infinite rotation fiber optic and slip ring joint  14  at the first infinite rotation joint  28 , the disc shaped spanner nut  112 , and the central axis spindle  50 . The cosmetic and protective cover  118  protects the second section  52  of the cabling system  22  connected to the infinite rotation fiber optic and slip ring joint  14  at the first infinite rotation joint  28  and hides the second section  52  of the cabling system  22  from exposure. 
     The illustrated second section  52  of the cabling system  22  extends through the extension arm  26  and is connected to a second one of the infinite rotation fiber optic and slip ring joints  14  at the second infinite rotation joint  32 . The second infinite rotation joint  32  includes an intersection of the extension arm  26  at the distal end  84  thereof and a proximal end  120  of the load counterbalancing spring arm  30 . The illustrated extension arm  26  includes a circular pivot tube receiving block  122  at the distal end  84  thereof, with the circular pivot tube receiving block  122  being connected to the hollow tube  82  of the extension arm  26 . The circular pivot tube receiving block  122  includes a side tube receiving bore  124  receiving the hollow tube  82  therein for fixing the hollow tube  82  to the circular pivot tube receiving block  122 . As illustrated in  FIG.  6   , the circular pivot tube receiving block  122  includes a stepped vertically oriented circular bearing tube receiving hole  126  extending therethrough. The stepped vertically oriented circular bearing tube receiving hole  126  includes a smaller diameter lower portion  121 , a larger diameter upper portion  123  and a step  125  between the smaller diameter lower portion  121  and the larger diameter upper portion  123 . A tubular sleeve  127  is located in the smaller diameter lower portion  121  and a top surface  129  of the tubular sleeve  127  abuts the step  125 . As illustrated in  FIG.  6   , the hollow tube  82  is inserted into the side tube receiving bore  124  until the hollow tube  82  abuts the exterior surface of the tubular sleeve  127 . 
     In the illustrated example, the tubular sleeve  127  is configured to receive a bearing tube  128  of the load counterbalancing spring arm  30  therein for connecting the load counterbalancing spring arm  30  to the extension arm  26 . An interior surface of the tubular sleeve  127  defines a circular inner bearing surface  132  within the circular pivot tube receiving block  122 . As illustrated in  FIG.  6   , an access area  134  is located in the circular pivot tube receiving block  122  above the tubular sleeve  127  for allowing the second section  52  of the cabling system  22  to pass from the hollow tube  82  and into the circular pivot tube receiving block  122 . It is contemplated that the circular pivot tube receiving block  122  could have an open top  136  covered by a removable cover  138 . The tubular sleeve  127  has an open bottom area  130  for receiving the bearing tube  128  of the load counterbalancing spring arm  30  therein. 
     The illustrated load counterbalancing spring arm  30  is configured to rotate about a second vertical axis  131  at the second infinite rotation joint  32  and a third vertical axis  133  at the third infinite rotation joint  34  (see  FIG.  2   ). The load counterbalancing spring arm  30  is also configured to allow the third infinite rotation joint  34  to move vertically relative to the second infinite rotation joint  32 . The load counterbalancing spring arm  30  includes a proximal knuckle member  146 , a central member  140  and a distal knuckle member  148 . The proximal knuckle member  146  has the bearing tube  128  extending therefrom for connecting the proximal knuckle member  146 , and thereby the load counterbalancing spring arm  30 , to the extension arm  26 . The proximal knuckle member  146  also includes the second vertical axis  131  extending therethrough. The proximal knuckle member  146  is pivotally connected to the central member  140  to allow the central member  140  to pivot about a first horizontal axis  142 . The central member  140  is also pivotally connected to the distal knuckle member  148  to allow the central member  140  to pivot about a second horizontal axis  144 . The distal knuckle member  148  also includes the third vertical axis  133  extending therethrough. The distal knuckle member  148  is connected to the wired medical unit  16  as discussed in more detail below. 
     In the illustrated example, the proximal knuckle member  146  has the bearing tube  128  extending therefrom for connecting the proximal knuckle member  146  to the extension arm  26 . The proximal knuckle member  146  includes a U-shaped side wall  154 , a bottom wall  156  and a top wall  158 , with the bearing tube  128  extending through an opening  151  in the top wall  158 . The U-shaped side wall  154  includes a curved wall section  166  below the circular pivot tube receiving block  122  and a pair of stepped side wall sections  180  extending from the curved wall section  166  to define an open end opposite the curved wall section  166 . Each of the stepped side wall sections  180  include a circular recessed area at a terminal end thereof for accepting disc projections  182  of the central member  140  as discussed in more detail below. The top wall  158  includes a substantially flat portion  184  connected to a top of the U-shaped side wall  154  and an arcuate portion  186  connected to the top of the circular recessed areas of the U-shaped side wall  154 . The bottom wall  156  includes a curved section  190  connected to a bottom of the U-shaped side wall  154  and an arcuate portion  192  connected to the bottom of the circular recessed areas of the U-shaped side wall  154 . As illustrated in  FIG.  6   , the bearing tube  128  extends upwardly out of the opening  151  in the flat portion  184  of the top wall  158  and directly into the tubular sleeve  127  of the circular pivot tube receiving block  122 . A fixing projection  200  extends from an inside face  202  of the U-shaped side wall  154  to connect the bearing tube  128  to the proximal knuckle member  146 . 
     The illustrated bearing tube  128  of the load counterbalancing spring arm  30  is inserted into the open bottom area  130  of the tubular sleeve  127  of the circular pivot tube receiving block  122  of the extension arm  26  to connect the load counterbalancing spring arm  30  to the extension arm  26 . The bearing tube  128  includes a bearing cylinder  160 , an upper bearing ring  162  connected to an upper area  164  of the bearing cylinder  160  and a middle bearing ring  165  connected to a middle area  168  of the bearing cylinder  160  directly above the top wall  158  of the proximal knuckle member  146 . The tubular sleeve  127  includes an upper circular recess  210  receiving the upper bearing ring  162  therein and a lower circular recess  212  receiving the middle bearing ring  165  therein for allowing the bearing tube  128 , and thereby the load counterbalancing spring arm  30 , to rotate relative to the extension arm  26 . The wired medical unit  16  is thereby allowed to rotate about the second vertical axis  131  at the second infinite rotation joint  32 . 
     In the illustrated example, one of the infinite rotation fiber optic and slip ring joints  14  at the second infinite rotation joint  32  is connected to the second section  52  of the cabling system  22  and a third section  170  of the cabling system  22  extending through the load counterbalancing spring arm  30  as discussed in more detail below. The stator  106  of the infinite rotation fiber optic and slip ring joint  14  at the second infinite rotation joint  32  is fixed to the bearing tube  128  by fasteners (or any other connection method) such that the stator  106  of the infinite rotation fiber optic and slip ring joint  14  at the second infinite rotation joint  32  is stationary relative to the load counterbalancing spring arm  30 . Likewise, the rotor  114  of the infinite rotation fiber optic and slip ring joint  14  at the second infinite rotation joint  32  is allowed to rotate relative to the stator  106 . 
     As illustrated in  FIGS.  4 ,  6  and  7   , the third section  170  of the cabling system  22  extends through the central member  140  of the load counterbalancing spring arm  30  and is connected to a third one of the infinite rotation fiber optic and slip ring joints  14  at the third infinite rotation joint  34 . The third infinite rotation joint  34  includes an intersection of the load counterbalancing spring arm  30  at the distal end  172  thereof and the wired medical unit  16 . The central member  140  of the load counterbalancing spring arm  30  is pivotally connected to the proximal knuckle member  146  at the first horizontal axis  142  to allow the wired medical unit  16  to rotate about the first horizontal axis  142 . The central member  140  is also pivotally connected to the distal knuckle member  148  at the second horizontal axis  144  to allow the wired medical unit  16  to rotate about the second horizontal axis  144 . 
     The illustrated load counterbalancing spring arm  30  is configured to have the central member  140  rotate simultaneously about the proximal knuckle member  146  and the distal knuckle member  148 . The central member  140  includes an outer shell  174  having a substantially rectangular cross-sectional shape. A parallel pair of the disc projections  182  extends from each end of the outer shell  174 . A parallelogram connection assembly  176  extends through the outer shell  174  and is connected to both the proximal knuckle member  146  and the distal knuckle member  148  to allow the central member  140  to rotate simultaneously about the proximal knuckle member  146  and the distal knuckle member  148 . 
     In the illustrated example, the distal knuckle member  148  connects the load counterbalancing spring arm  30  to the wired medical unit  16 . The distal knuckle member  148  includes a U-shaped side wall  220 , a bottom wall  222  and a top wall  224 , with a down tube  226  extending downwardly from the bottom wall  222  for connection to the display support assembly  18  of the wired medical unit  16 . The U-shaped side wall  220  includes a curved wall section  228  coextensive with the down tube  226  and a pair of stepped side wall sections  230  extending from the curved wall section  228  to define an open end opposite the curved wall section  228 . Each of the stepped side wall sections  230  include a circular recessed area at a terminal end thereof for accepting disc projections  182  of the central member  140  as discussed in more detail below. The top wall  224  includes an angled portion  232  connected to a top of the U-shaped side wall  220  and an arcuate portion  234  connected to the top of the circular recessed areas of the U-shaped side wall  220 . The bottom wall  222  is arcuate and is connected to a bottom of the U-shaped side wall  220 . 
     The illustrated parallelogram connection assembly  176  extends between and is connected to the proximal knuckle member  146  and the distal knuckle member  148 . The parallelogram connection assembly  176  includes an upper rod  250 , a lower rod  252 , a proximal knuckle connection  254  and a distal knuckle connection  256 . The proximal knuckle connection  254  includes a pair of parallel plates  258  extending between the arcuate portion  186  of the top wall  158  and the arcuate portion  192  of the bottom wall  156  of the proximal knuckle member  146 . The upper rod  250  is located between the parallel plates  258  and pivotally connected thereto by a pivot pin  260  located at the first horizontal axis  142  to allow the upper rod  250  to pivot about the first horizontal axis  142 . The lower rod  252  is pivotally connected to an outside face  262  of one of the parallel plates  258  by a pivot pin  264 . Like the proximal knuckle connection  254 , the distal knuckle connection  256  includes a pair of parallel plates  266  extending between the arcuate portion  234  of the top wall  224  and the bottom wall  222  of the distal knuckle member  148 . The upper rod  250  is located between the parallel plates  266  and pivotally connected thereto by a pivot pin  268  located at the second horizontal axis  144  to allow the upper rod  250  to pivot about the second horizontal axis  144 . The lower rod  252  is pivotally connected to an outside face  262  of one of the parallel plates  266  by a pivot pin  270 . 
     In the illustrated example, the parallelogram connection assembly  176  allows the second horizontal axis  144  to move vertically relative to the first horizontal axis  142 . As the distal knuckle member  148  is lowered, the upper rod  250  will pivot about the pivot pin  260  located at the first horizontal axis  142 , which will also force the lower rod  252  to pivot about the pivot pin  264  at the proximal knuckle member  146 . Because the upper rod  250  and the lower rod  252  of the parallelogram connection assembly  176  form a parallelogram with the parallel plates  258  in the proximal knuckle member  146  and the parallel plates  266  in the distal knuckle member  148 , the distal knuckle member  148  will not rotate as the distal knuckle member  148  is lowered (that is, a line between the pivot pin  260  and the pivot pin  264  in the proximal knuckle member  146  will remain substantially parallel to a line between the pivot pin  268  and the pivot pin  268  in the distal knuckle member  148 , with both lines remaining substantially vertical). As is well known to those skilled in the art, a spring can be located within the central member  140  (e.g., partially surrounding the upper rod  250 ) to maintain the parallelogram connection assembly  176  in a selected rotated position. 
     The illustrated central member  140  covers the pivot areas of the load counterbalancing spring arm  30 . The outer shell  174  of the central member  140  includes a top wall  280  that rides on the arcuate portion  186  of the top wall  158  of the proximal knuckle member  146  and the arcuate portion  234  of the top wall  224  and the bottom wall  222  of the distal knuckle member  148  during lowering and raising of the load counterbalancing spring arm  30 . Likewise, the outer shell  174  of the central member  140  includes a bottom wall  282  that rides on the arcuate portion  192  of the bottom wall  156  of the proximal knuckle member  146  and the bottom wall  222  of the distal knuckle member  148  during lowering and raising of the load counterbalancing spring arm  30 . Each end of the side walls  284  of the outer shell  174  of the central member  140  have one of the disc projections  182  extending therefrom. The disc projections  182  cover the circular recessed area at the terminal ends of the stepped side wall sections  180  of the U-shaped side wall  154  of the proximal knuckle member  146  to form a cosmetic joint. The disc projections  182  also cover the circular recessed area of the pair of stepped side wall sections  230  of the U-shaped side wall  220  of the distal knuckle member  148  to form a cosmetic joint. 
     In the illustrated example, the distal knuckle member  148  connects the load counterbalancing spring arm  30  to the wired medical unit  16 . The down tube  226  of the distal knuckle member  148  receives a bushing cylinder  300  of the display support assembly  18  therein to connect the distal knuckle member  148 , and thereby the load counterbalancing spring arm  30 , to the display support assembly  18 . The display support assembly  18  includes an inverted U-shaped frame member  302 , an arm connection assembly  304  connected to a top of the inverted U-shaped frame member  302  and a pair of display pivot brackets  306 . The arm connection assembly  304  includes a split sleeve  308  that surrounds the top of the inverted U-shaped frame member  302 , with the bushing cylinder  300  extending upwardly from a center of the split sleeve  308 . The bushing cylinder  300  includes an upper cylindrical bushing  320  located in an upper bushing channel  322  in an outside surface  324  of the bushing cylinder  300  and a lower cylindrical bushing  326  located in a lower bushing channel  328  in the outside surface  324  of the bushing cylinder  300 . A pin slot  330  extends around the perimeter of the bushing cylinder  300  between the upper bushing channel  322  and the lower bushing channel  328 . 
     The illustrated wired medical unit  16  is connected to the distal knuckle member  148  of the load counterbalancing spring arm  30  by inserting the bushing cylinder  300  of the display support assembly  18  into the down tube  226  of the distal knuckle member  148 . As illustrated in  FIG.  7   , the down tube  226  of the distal knuckle member  148  has a radial pin opening  332  extending through a wall  334  of the down tube  226 . When the bushing cylinder  300  of the display support assembly  18  is fully inserted into the down tube  226  of the distal knuckle member  148 , the radial pin opening  332  in the wall  334  of the down tube  226  is aligned with the pin slot  330  in the bushing cylinder  300 . A yoke retaining clip  336  extends through the radial pin opening  332  and into the pin slot  330  in the bushing cylinder  300  to connect the wired medical unit  16  to the distal knuckle member  148 . The yoke retaining clip  336  also allows the wired medical unit  16  to rotate about the distal knuckle member  148  at the third vertical axis  133 . Once the yoke retaining clip  336  is inserted into the radial pin opening  332  and the pin slot  330 , a cylindrical retaining clip sleeve  340  surrounding the down tube  226  is slid downward to cover the radial pin opening  332  in the wall  334  of the down tube  226  to lock the yoke retaining clip  336  in position. A fastener  342  can be inserted through the cylindrical retaining clip sleeve  340  and into the down tube  226  to lock the cylindrical retaining clip sleeve  340  in position. 
     In the illustrated example, one of the infinite rotation fiber optic and slip ring joints  14  at the third infinite rotation joint  34  is connected to the third section  170  of the cabling system  22  and a fourth section  350  of the cabling system  22  extending to the display monitor  20 . The stator  106  of the infinite rotation fiber optic and slip ring joint  14  at the third infinite rotation joint  34  is fixed to the down tube  226  of the distal knuckle member  148  by fasteners (or any other connection method) such that the stator  106  of the infinite rotation fiber optic and slip ring joint  14  at the third infinite rotation joint  34  is stationary relative to the load counterbalancing spring arm  30 . Likewise, the rotor  114  of the infinite rotation fiber optic and slip ring joint  14  at the third infinite rotation joint  34  is allowed to rotate relative to the stator  106 . 
     The illustrated fourth section  350  of the cabling system  22  extends through the down tube  226  of the distal knuckle member  148  of the load counterbalancing spring arm  30 , the bushing cylinder  300  of the arm connection assembly  304 , the inverted U-shaped frame member  302 , and to the display pivot brackets  306 . As illustrated in  FIGS.  1 - 4   , the display pivot brackets  306  are connected to a display frame and cable shield  360  holding the display monitor  20  and allow the display monitor  20  to pivot about the display pivot brackets  306 . The display frame and cable shield  360  can have a handle  362  to assist in positioning the display monitor  20  to a desired position. It is contemplated that the handle  362  can be removable for sterilization and/or can have a removable/replaceable sterilizable cover. 
     The illustrated cabling system  22  provides power and information to the wired medical unit  16  through the display support assembly  18 . It is contemplated that each of the infinite rotation fiber optic and slip ring joints  14  can transmit any combination of the following: digital data through a fiber optic connection, digital or analog data through at least one coaxial cable connection, digital or analog data through at least one serial data connection, low voltage power through at least one low voltage power connection, AC power through at least one AC power connection, and a ground wire connection. 
       FIG.  8    illustrates the power and information transmitted through the cabling system  22  and each of the infinite rotation fiber optic and slip ring joints  14  of the illustrated embodiment. The illustrated cabling system  22  includes a fiber optic cable  500  leading into and out of each infinite rotation fiber optic and slip ring joint  14 , a pair of ground wires  502  leading into and out of each infinite rotation fiber optic and slip ring joint  14 , a pair of AC power wires  504  leading into and out of each infinite rotation fiber optic and slip ring joint  14 , four low voltage wires  506  leading into and out of each infinite rotation fiber optic and slip ring joint  14 , four twisted pairs of serial data wires  508  leading into and out of each infinite rotation fiber optic and slip ring joint  14  and four coaxial cables  510  leading into and out of each infinite rotation fiber optic and slip ring joint  14 . However, it is contemplated that the cabling system  22  could have more or less of the wires and cables outlined above. 
     The following chart lists examples of the cables and wires leading into and out of each infinite rotation fiber optic and slip ring joint  14 : 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
               
               
                 Function: 
                 Cable type: 
                 Size: 
                 Type: 
                 Volts: 
                 Amps: 
                 Data type: 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Video and Audio 
                 Fiber optic 
                 50 μm 
                   
                   
                   
                   
                 HD-SDI, DVI, 
               
               
                 Data transmission 
                   
                 broadband 
                   
                   
                   
                   
                 HDMI, any 
               
               
                   
                   
                 with a 3 mm 
                   
                   
                   
                   
                 HD signals, 
               
               
                   
                   
                 jacket 
                   
                   
                   
                   
                 any SD 
               
               
                   
                   
                   
                   
                   
                   
                   
                 signals, 
               
               
                   
                   
                   
                   
                   
                   
                   
                 Ethernet, 
               
               
                   
                   
                   
                   
                   
                   
                   
                 network and 
               
               
                   
                   
                   
                   
                   
                   
                   
                 other data 
               
               
                 Video and Audio 
                 Coaxial 
                   
                 RG-179 
                 10 
                 100 
                 mA max 
               
               
                 Data transmission 
                 cable 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Serial Data 
                 Serial Cable 
                 26-28 
                 AWG 
                   
                 10 
                 100 
                 mA max 
                 RS-232, RS- 
               
               
                 transmission 
                 in Twisted 
                   
                   
                   
                   
                   
                   
                 485, CAN, etc. 
               
               
                   
                 Pairs 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Low Voltage 
                 Cu or Al 
                 26-28 
                 AWG 
                   
                 28 
                 max 
                 1000 
                 mA max 
                   
               
               
                 Power 
                 wire 
               
               
                 AC Power 
                 Cu or Al 
                 16-18 
                 AWG 
                   
                 120-240 
                 VAC 
                 10 
                 A 
               
               
                   
                 wire 
               
               
                 Ground 
                 Cu or Al 
                 18 
                 AWG 
                   
                 120-240 
                 VAC 
                 10 
                 A 
               
               
                   
                 wire 
               
               
                   
               
            
           
         
       
     
     It is contemplated that the fiber optic cable  500  can be single mode or multimode and can have at least 10 Gb of bandwidth. The coaxial cables  510  can have an impedance of 75Ω and can be a coaxial cable sold as part number MOGAMI W3351 by MIT Inc. of Tokyo, Japan. The AC power wires  504  can be a power line sold as part number 3516/19 by Weico Wire &amp; Cable Inc. of Edgewood, N.Y. 
     In the illustrated example, the infinite rotation fiber optic and slip ring joints  14  ( FIGS.  9 A- 11   ) transmit all of the data and power through the first infinite rotation joint  28 , the second infinite rotation joint  32  and the third infinite rotation joint  34 . The infinite rotation fiber optic and slip ring joint  14  includes a slip ring housing  520  and a fiber optic rotary joint  522  within the slip ring housing  520 . The slip ring housing  520  includes the rotor  114  and the stator  106 . The stator  106  includes an exterior stator cylinder  524  having a rotor end wall  526  and an exit end wall  528 . An internal stator cylinder  530  substantially co-axial with the exterior stator cylinder  524  is connected to the exit end wall  528 . A wiring area  532  is defined between the exterior stator cylinder  524  and the internal stator cylinder  530 . A stator and fiber optic rotary joint area  534  is defined within the internal stator cylinder  530 . 
     The illustrated rotor  114  includes an exterior cylindrical portion  536  extending from the rotor end wall  526  of the stator  106  and an interior portion  538  located within the stator and fiber optic rotary joint area  534  of the stator  106 . The exterior cylindrical portion  536  defines a tubular housing  540  having an entrance end  535  opposite the stator  106 . The fiber optic cable  500  enters the entrance end  535  of the exterior cylindrical portion  536  of the rotor  114  through a center portion thereof. It is contemplated that the fiber optic cable  500  outside of the rotor  114  can have a connector  542  (e.g., a SC, LC, FC, ST, SMA or pigtail type connector) for connecting the fiber optic cable  500  passing through the infinite rotation fiber optic and slip ring joint  14  to the fiber optic cable  500  of the first section  46 , the second section  52 , the third section  170  or the fourth section  350  of the cabling system  22 . It is also contemplated that the fiber optic cable  500  can run uninterrupted up to and between the infinite rotation fiber optic and slip ring joints  14 . The ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  enter the entrance end  535  of the exterior cylindrical portion  536  of the rotor  114  adjacent a peripheral edge  544  of the entrance end  535 . 
     The illustrated ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  entering the exterior cylindrical portion  536  of the rotor  114  are connected to a center rotating shaft  546  made up of a plurality of individual contact rings  551  and forming the interior portion  538  of the rotor  114 . Each of the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the serial data wires  508  and the coaxial cables  510  are connected to one of the individual contact rings  551  of the center rotating shaft  546 . As illustrated in  FIGS.  10  and  11   , each of the individual contact rings  551  are separate by an insulation ring  553  to prevent power or data from crossing over to adjacent individual contact rings  551 . Each of the individual contact rings  551  include a plurality of circumferential grooves  560  for receiving contact members  562  of the stator  106  as discussed in more detail below. It is contemplated that the individual contact rings  551  transferring power can be located closer to the exterior cylindrical portion  536  of the rotor  114 , can have larger diameters and can have adjacent insulation rings  553  with a greater thickness (see  FIG.  10   ) than the individual contact rings  551  transferring data (see  FIG.  11   ). The center rotating shaft  546  includes a plurality of terminal end openings  564  for accepting fasteners  566  therein to connect a rotor portion  568  of the fiber optic rotary joint  522  to the center rotating shaft  546 . The center rotating shaft  546  also includes a circumferential groove  548  at an end thereof opposite the exterior cylindrical portion  536  of the rotor  114 . A bearing ring  550  is located within the circumferential groove  548  to support the center rotating shaft  546  and to allow the center rotating shaft  546  to rotate within the stator  106 . 
     The illustrated stator  106  includes a portion of the rotor  114  therein to receive data and power from the rotor  114 . The stator  106  includes the exterior stator cylinder  524  having the rotor end wall  526  and the exit end wall  528 , with the internal stator cylinder  530  extending substantially co-axial with the exterior stator cylinder  524  from the exit end wall  528 . The internal stator cylinder  530  includes an enlarged abutment area  570  abutting the bearing ring  550  located within the circumferential groove  548  of the center rotating shaft  546  of the rotor  114  to allow the center rotating shaft  546  and the rotor  114  to rotate relative to the stator  106 . The contact members  562  extend through the internal stator cylinder  530  (see  FIGS.  10  and  11   ) and make contact with the plurality of circumferential grooves  560  in the individual contact rings  551  of the internal stator cylinder  530 . The contact members  562  on the outside surface of the internal stator cylinder  530  are engaged with the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  exiting the stator  106 . As illustrated in  FIGS.  9 A and  9 B , the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  exit the exit end wall  528  through openings  591  located adjacent the periphery of the exit end wall  528  in wiring groups  593 . 
     The power and data is transferred from the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  entering the infinite rotation fiber optic and slip ring joint  14  to the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  exiting the infinite rotation fiber optic and slip ring joint  14 . As discussed above, the power and data is first transferred from the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  entering the infinite rotation fiber optic and slip ring joints  14  to the individual contact rings  551  of the center rotating shaft  546 . The contact members  562  extending through the internal stator cylinder  530  of the stator  106  make contact with the plurality of circumferential grooves  560  in the individual contact rings  551  of the internal stator cylinder  530  to transfer the power and data. It is contemplated that the contact members  562  can be brushes (e.g., graphite particles dispersed in a matrix of silver with the individual contact rings  551  also being made of silver, gold alloys forming a mono or multi-filament brush with the individual contact rings  551  also be made of a gold based alloy, etc.), a flexure ring that bridges the outer ring and the inner ring and that moves like balls in a ball bearing, or liquid mercury. The power and data is thereafter transferred through the contacts to the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  entering the infinite rotation fiber optic and slip ring joint  14  to the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508  and the coaxial cables  510  exiting the infinite rotation fiber optic and slip ring joint  14 . While power and data is discussed above and travelling only in one direction from the rotor  114  to the stator  106 , the power and data can travel in both directions through the infinite rotation fiber optic and slip ring joint  14 . Moreover, the infinite rotation fiber optic and slip ring joint  14  is capable of being orientated in any direction (e.g., either the stator  106  or the rotor  114  being located first in the direction of data and power in the cabling system  22  to the wired medical unit  16 ). The fiber optic cable  500  exits the exit end wall  528  of the stator  106  through a center portion thereof. It is contemplated that the fiber optic cable  500  outside of the stator  106  can have the connector  542  (e.g., a SC, LC, FC, ST, SMA or pigtail type connector) for connecting the fiber optic cable  500  passing through the infinite rotation fiber optic and slip ring joint  14  to the fiber optic cable  500  of the first section  46 , the second section  52 , the third section  170  or the fourth section  350  of the cabling system  22 . It is also contemplated that the fiber optic cable  500  can run uninterrupted up to and between the infinite rotation fiber optic and slip ring joints  14 . 
     In the illustrated example, data also passes through the infinite rotation fiber optic and slip ring joint  14  through the fiber optic rotary joint  522  within the slip ring housing  520 . The fiber optic rotary joint  522  includes the rotor portion  568  and a stator portion  580 . The rotor portion  568  includes increasing larger diameter areas having an entrance end  582  and a stator connection end  584 . A largest diameter area  586  of the rotor portion  568  includes the fasteners  566  extending therethrough and into the terminal end openings  564  of the center rotating shaft  546  of the rotor  114  to force the rotor portion  568  of the fiber optic rotary joint  522  to rotate with the remainder of the rotor  114 . The stator portion  580  of the fiber optic rotary joint  522  is rotatably connected to the rotor portion  568 . The stator portion  580  of the fiber optic rotary joint  522  includes a head  590  connected to the exit end wall  528  of the exterior stator cylinder  524  of the stator  106  such that the stator portion  580  of the fiber optic rotary joint  522  remains stationary with the remainder of the stator  106 . 
     The illustrated fiber optic cable  500  enters the rotor  114  through the entrance end  535  of the tubular housing  540  of the exterior cylindrical portion  536  of the rotor  114  and exits the stator  106  through the head  590  of the stator portion  580  of the fiber optic rotary joint  522 . The fiber optic cable  500  is split within the fiber optic rotary joint  522  such that a first portion  600  of the fiber optic cable  500  within the fiber optic rotary joint  522  rotates with the rotor portion  568  of the fiber optic rotary joint  522  and a second portion  602  of the fiber optic cable  500  within the fiber optic rotary joint  522  remains stationary with the stator portion  580  of the fiber optic rotary joint  522 . The data is transferred from the first portion  600  of the fiber optic cable  500  to the second portion  602  of the fiber optic cable  500  in a manner well known to those skilled in the art. The fiber optic rotary joint  522  can be the fiber optic rotary joint disclosed in U.S. Patent Application Publication No. 2009/0226131 entitled “FIBER OPTIC ROTARY COUPLER,” the entire contents of which are hereby incorporated herein by reference. The fiber optic rotary joint  522  can also be a fiber rotary joint sold as part number MJXX-131-50T-STD or MJXX-131-50T-STP by Princetel, Inc. of Hamilton, N.J. The fiber optic rotary joint  522  can be made of any suitable material (e.g., stainless steel). 
     In the illustrated embodiment, the data passing through the fiber optic cable  500  can be subjected to an optical multiplexer  700  before the data passes through the fiber optic rotary joint  522  and then passed through an optical demultiplexer  702  before passing the data to the wired medical unit  16 . For example, as illustrated in  FIG.  12   , a plurality of video signals  704  can be passed through an electric to optical transceiver  706 , with each of the video signals  704  having different wavelengths, before the video signals  704  are passed to the optical multiplexer  700 . Furthermore, an audio signal  708  can be passed through an electric to optical transceiver  710  before the audio signal  708  is passed to the optical multiplexer  700 . Moreover, a plurality of control signals  712  can be passed through an electric to optical transceiver  714 , with each of the control signals  712  having different wavelengths, before the control signals  712  are passed to the optical multiplexer  700 . Likewise, a plurality of network signals  716  can be passed through an electric to optical transceiver  718 , with each of the network signals  716  having different wavelengths, before the network signals are passed to the optical multiplexer  700 . Each of the video signals  704 , the audio signal  708 , the control signals  712  and the network signals  716  are at different wavelengths before the signals are passed to the optical multiplexer  700 , where the signals are combined. The optical demultiplexer  702  separates the signals and optical to electrical transceivers  720  will transform the video signals  704 , the audio signal  708 , the control signals  712  and the network signals  716  from optical signals to electrical signals. The optical multiplexer  700  and the optical demultiplexer  702  allow for multiple signals to be passed through the fiber optic cable  500  and the fiber optic rotary joints  522 . Use of the optical multiplexer  700  and the optical demultiplexer  702  for passing multiple signals through cables is well known to those skilled in the art. Using the optical multiplexer  700  and the optical demultiplexer  702 , multiple data can be sent through a single wire. For example, an HDMI signal with 4k resolution along with a bidirectional Ethernet signal through the fiber optic cable  500 . Although the optical multiplexer  700  is referred to as a multiplexer and the optical demultiplexer  702  is referred to as a demultiplexer, both the optical multiplexer  700  and the optical demultiplexer  702  are both multiplexers and demultiplexers because the data flows in both directions (i.e., is bidirectional). It is contemplated that circulators could be used in concert with the optical multiplexer  700  and the optical demultiplexer  702  to double the capacity of the fiber optic cable  500 . 
     The suspension arm assembly  10  of the present invention is illustrated as having the arms  12  in a single line having a single end point such that only two arms  12  meet at the infinite rotation joints. However, it is contemplated that three or more arms  12  could meet at a single joint. In such an arrangement, at least one of the ground wires  502 , the AC power wires  504 , the low voltage wires  506 , the twisted pairs of serial data wires  508 , the coaxial cables  510  and the fiber optic cable  500  could continue along each branch of the arms  12  at the infinite rotation joints. Furthermore, it is contemplated that the wires and/or cables could be split at the infinite rotation joints such that the power and data is sent along each branch of arms  12  to the wire medical units  16  at the end of each branch.  FIG.  12    illustrates a situation wherein the data from the optical multiplexer  700  is split off into a branch line  750  at an infinite rotation joint and sent to a second optical demultiplexer  752  before being sent to an optical to electrical transceivers  720  and ultimately to a second wired medical unit  16 . 
     In an aspect of the present invention, multiple data and power signals can be sent along the arms  12  of the suspension arm assembly  10  having multiple infinite rotation joints with unlimited range (i.e., unlimited range of rotation and number of rotations). Therefore, the suspension arm assembly  10  allows for a large data transfer rate while simultaneously allowing the suspension arm assembly  10  to be fully and easily adjustable to any desired location. The arms  12  can be made of any material (e.g., plastic and/or metal) and can be sealed to prevent contamination from entering the suspension arm assembly  10 , Furthermore, the arms  12  can have any cross-sectional shape (e.g., square, circular and/or rectangular). Moreover, it is contemplated that the suspension arm assembly  10  could include mechanisms to hold the arms  12  in a particular rotated position (e.g., springs, balls, wedges, toggles, etc.). Additionally, it is contemplated that the cabling  22  could have one or a plurality of connectors (e.g., a SC, LC, FC, ST, SMA or pigtail type connector) within each arm for connecting a first part of the cabling in an arm to a second part of the cabling in an arm (e.g., to assist in routing the cabling  22  through each arm). Furthermore, it is contemplated that the cabling  22  only need to extend to an end item requiring the high definition data (which includes ultrahigh definition data and data that results in resolution above standard definition resolution) to be sent thereto (e.g., if a monitor is directly connected the extension arm  26 , the fiber optic cable could only travel through the first infinite rotation joint  28  to the monitor, with other cabling traveling through the arms  12  to another area of the arms). If the cabling  22  does not travel to the end of the arms  12 , it is contemplated that the arms after the end of the cabling do not need to have any further infinite rotation joints. Furthermore, it is contemplated that less than all of the joints of the suspension arm assembly  10  could have infinite rotation. For example, it is contemplated that the first joint  28  or both the first joint  28  and the second joint  30  could include stops preventing unlimited rotation at these joints. In such a situation, it is contemplated that the infinite rotation fiber optic and slip ring joint  14  could still be used at these joints to transmit power and data, only with stops limiting rotation, or that these joints could have other configurations for transmitting power and data with mechanical stops limiting rotation (with, for example, all of the wiring passing directly through these joints). 
     The reference numeral  10   a  ( FIG.  13   ) generally designates another embodiment of the present invention, having a second embodiment for the suspension arm assembly. Since suspension arm assembly  10   a  is similar to the previously described suspension arm assembly  10 , similar parts appearing in  FIGS.  1 - 12    and  FIG.  13   , respectively, are represented by the same, corresponding reference number, except for the suffix “a” in the numerals of the latter. The second embodiment of the suspension arm assembly  10   a  is substantially similar to the first embodiment of the suspension arm assembly  10 , except that the second embodiment of the suspension arm assembly  10   a  includes a separable infinite rotation fiber optic and slip ring joint  800  in place of the infinite rotation fiber optic and slip ring joint  14 . The separable infinite rotation fiber optic and slip ring joint  800  is located at any or all of the first infinite rotation joint  28   a  between the ceiling attachment member  24   a  and the extension arm  26   a , the second infinite rotation joint  32   a  between the extension arm  26   a  and the load counterbalancing spring arm  30   a , and the third infinite rotation joint  34   a  between the display support assembly  18   a  and the load counterbalancing spring arm  30   a . The separable infinite rotation fiber optic and slip ring joint  800  allows for automatic connection of the fiber optic cable and the remaining wires of the cabling system on both sides of the joints  28   a ,  30   a ,  32   a  when the elements on both sides of the joints  28   a ,  30   a ,  32   a  are connected (e.g., when the extension arm  26   a  is connected to the ceiling attachment member  24   a ). The separable infinite rotation fiber optic and slip ring joint  800  allows for easier assembly of the suspension arm assembly  10   a . It is contemplated that the separable infinite rotation fiber optic and slip ring joint  800  could be used at any intersection or joint for allowing for unlimited rotation of the joint along with passing information through the joint via a fiber optic cable and other wiring. 
     In the illustrated example, the separable infinite rotation fiber optic and slip ring joint  800  is configured to be separated to allow for easy assembly and disassembly. It is contemplated that the separable infinite rotation fiber optic and slip ring joint  800  could be separable by having the rotor  114   a  being separable from the stator  106   a , by having a two-part separable rotor  114   a  and/or by having a two-part separable stator  106   a . In the illustrated embodiment, the separate parts of the separable infinite rotation fiber optic and slip ring joint  800  automatically engage when the elements on both sides of the joints  28   a ,  30   a ,  32   a  are connected. Therefore, the separable elements of the separable infinite rotation fiber optic and slip ring joint  800  can be connected without using any tools directly thereon to be able to pass signals over the fiber optic cable and the wires of the separable infinite rotation fiber optic and slip ring joint  800 . 
       FIGS.  13 - 33    illustrate an embodiment of the separable infinite rotation fiber optic and slip ring joint  800  wherein the separable infinite rotation fiber optic and slip ring joint  800  is separable by having a two-part separable rotor  114   a . The two-part separable rotor  114   a  includes a main rotor  802  and a rotor connector  804  that is removably connected to the main rotor  802 . The main rotor  802  in the illustrated embodiment is fixed to the stator  106   a . In the present example, when any of the arms  12   a  are connected together, the main rotor  802  and the stator  106   a  will be fixed together in one arm  12   a  and the rotor connector  804  will be in the other arm  12   a . While the rotor connector  804  in  FIG.  13    is illustrated as not being connected to the adjacent element (e.g., the ceiling attachment member  24   a  or the extension arm  26   a  at the second infinite rotation joint  32   a ) the rotor connector  804  would be fixed to the adjacent element as the suspension arm assembly  10   a  is assembled. Likewise, the main rotor  802  and the stator  106   a  will also be fixed to the adjacent element (e.g., the extension arm  26   a  at the first infinite rotation joint  28   a ) as the suspension arm assembly  10   a  is assembled. Each of the separable parts of the separable infinite rotation fiber optic and slip ring joint  800  (whether the rotor and stator are separable or when the rotor or the stator are in two separate parts) will be fixed to the adjacent element as the suspension arm assembly  10   a  is assembled. Moreover, each of the separable parts of the separable infinite rotation fiber optic and slip ring joint  800  (whether the rotor and stator are separable or when the rotor or the stator are in two separate parts) would be attached to their respective arm components (e.g. spring arm, extension arm), and would remain attached to the arm components during disassembly (i.e., separation of the arm components). 
     The illustrated main rotor  802  ( FIGS.  14 - 19   ) connects to the rotor connector  804  to form the separable infinite rotation fiber optic and slip ring joint  800 . The main rotor  802  includes a stepped tube  806  having a small insertion tube section  808 , a large outer tube section  810  and a stepped section  812  between the small insertion tube section  808  and the large outer tube section  810 . The stepped tube  806  has an axial opening  814  therethrough for accommodating the fiber optic cable as discussed in more detail below. The small insertion tube section  808  has an insertion end  816  opposite the stepped section  812  configured to be inserted into the stator  106   a . The stepped section  812  includes a first radial abutment face  826  at the small insertion tube section  808 , a step surface  818  having a circumferential groove  820  therein and a second radial abutment face  828  at the large outer tube section  810 . The circumferential groove  820  on the step surface  818  of the stepped section  812  is configured to receive a pair of locking members  822  to fix the main rotor  802  to the stator  106   a . The large outer tube section  810  includes an axial counterbore  824  facing away from the stepped section  812  for receiving the rotor connector  804  therein. 
     The illustrated main rotor  802  has a plurality of conduit paths therethrough. Each conduit path is formed by a contact ring  813 , an interior conductive path  830  and an extension pin  832 . As illustrated in  FIGS.  16  and  18   , the small insertion tube section  808  includes a plurality of circumferential orientated and axially spaced channels  811 , with each channel  811  receiving one of the contact rings  813  therein. An interior surface of each of the contact rings  813  abuts one of the interior conductive paths  830 , which pass through the stepped section  812  to engage the extension pin  832  that extends into the axial counterbore  824  in the large outer tube section  810  (see  FIG.  19   ). The interior conductive paths  830  are each located at a different radial position within the stepped section  812  (with only one of the interior conductive paths  830  being illustrated in  FIGS.  16  and  17   ).  FIG.  19    illustrates an example of radial positions of the extension pins  832 , with the conductive paths  830  substantially corresponding to the radial positions of the extension pins  832 . While nine groups of contacts each comprising one of the contact rings  813 , one of the conductive paths  830  and one of the extension pins  832  are shown, it is contemplated that any number of groups of contacts could be used. In the illustrated embodiment, the three contact rings  813  closest to the stepped section  812  conduct power (e.g., ground, AC power and low voltage) and the remaining contact rings  813  conduct data. Each of the extension pins  832  is received within a corresponding slot in the rotor connector  804  as discussed in more detail below. 
     In the illustrated example, the stator  106   a  fixedly receives the main rotor  802  therein. The stator  106   a  ( FIGS.  14 - 18  and  20 - 24   ) includes an outer housing  834  and an inner housing  836  received within the outer housing  834 . The inner housing  836  ( FIGS.  16 ,  17 ,  20  and  21   ) includes an inner housing cylinder  838  having a main rotor receiving end  835  and a closed end  837 . The inner housing cylinder  838  includes a plurality of axially extending data leaf spring contact channels  840  for accepting data leaf spring contacts  842  ( FIG.  25   ) therein (see  FIG.  20   ). Each of the data leaf spring contact channels  840  includes an axially open side  844  at the closed end  837  of the inner housing cylinder  838  and an inner stop wall  848  opposite the closed end  837 . As illustrated in  FIG.  21   , the data leaf spring contact channels  840  include a radial opening  850  into an interior of the inner housing cylinder  838  adjacent the inner stop wall  848 . Each of the radial openings  850  are at different axial positions to allow the data leaf spring contacts  842  within each data leaf spring contact channel  840  to contact a different one of the data contact rings  813  in the main rotor  802  of the rotor  114   a . The illustrated example includes a pair of opposite sets of data leaf spring contact channels  840 , with three data leaf spring contact channels  840  in each set. However, any number of data leaf spring contact channels  840  could be used. 
     The illustrated inner housing cylinder  838  also includes a plurality of axially extending power leaf spring contact channels  841  for accepting power leaf spring contacts  843  therein (see  FIG.  20   ). Each of the power leaf spring contact channels  841  includes a radially and axially open side  845  at the closed end  837  of the inner housing cylinder  838 . As illustrated in  FIG.  21   , the power leaf spring contact channels  841  include a radial opening  851  into an interior of the inner housing cylinder  838  at an end of the power leaf spring contact channels  841  opposite the closed end  837  of the inner housing cylinder  838 . Each of the radial openings  851  are at different axial positions to allow the power leaf spring contacts  843  within each power leaf spring contact channel  841  to contact a different one of the power contact rings  813  in the main rotor  802  of the rotor  114   a.    
     As illustrated in  FIG.  21   , the inner housing  836  includes a closed end wall  852  axially spaced from the closed end  837 , with the closed end wall  852  being axially located such that the radially and axially open side  845  of the power leaf spring contact channels  841  are located between the closed end wall  852  and the closed end  837  of the inner housing  836 . A central tube  854  extends through the closed end wall  852  from the closed end  837  and into an interior of the inner housing  836 , wherein the central tube  854  includes an exterior section  856  and an interior alignment section  858 . As illustrated in  FIG.  21   , a spanning member  860  extending radially from the exterior section  856  of the central tube  854  divides a pair of the power leaf spring contact channels  841 . 
     In the illustrated example, the outer housing  834  of the stator  106   a  accepts the inner housing  836  of the stator  106   a  therein. The outer housing  834  includes an outer housing cylinder  862  having a receiving end  864  and a closed end  866 . The outer housing cylinder  862  includes a pair of circumferential slots  868  adjacent the receiving end  864  for receiving the locking members  822  therein for locking the main rotor  802  to the stator  106   a  as discussed in more detail below. The outer housing cylinder  862  includes a recessed area  870  extending axially from the closed end  866  to a stepped bottom edge  872 . The recessed area  870  defines a section of the outer housing cylinder  862  with a thickness smaller than the remaining portion of the outer housing cylinder  862 . The closed end  866  of the outer housing cylinder  862  includes an interrupted end cap  874  including a first C-shaped portion  876 , a second C-shaped portion  878  and a triangular portion  880 . A plurality of axial openings  882  extend into the recessed area  870  between each of the first C-shaped portion  876 , the second C-shaped portion  878  and the triangular portion  880 . A radially inner edge  884  of the first C-shaped portion  876  includes a plurality of grooves  886  for receiving a portion of the data leaf spring contacts  842  therein and a radially inner edge  888  of the second C-shaped portion  878  includes a plurality of grooves  890  for receiving a portion of the data leaf spring contacts  842  therein. 
     The illustrated data leaf spring contacts  842  ( FIG.  25   ) are configured to be located between the inner housing  836  and the outer housing  834  of the stator  106   a . The data leaf spring contacts  842  each include a central flat portion  892 , a pair of contact leaf springs  894  at a first edge of the central flat portion  892  and an L-shaped connecter  896  having a hole  898  at the second edge of the central flat portion  892 . As illustrated in  FIG.  20   , the central flat portions  892  of the data leaf spring contacts  842  are received within the data leaf spring contact channels  840  of the inner housing cylinder  838 . The pair of contact leaf springs  894  of the data leaf spring contacts  842  extend through the radial opening  850  to contact the contact rings  813  as illustrated in  FIGS.  16  and  17   . An interior surface of the outer housing cylinder  862  includes a plurality of axially extending projections  900  for holding the central flat portion  892  of the data leaf spring contacts  842  in place within the data leaf spring contact channels  840  when the inner housing  836  is inserted into the outer housing  834 . The L-shaped connecter  896  of the data leaf spring contacts  842  abuts an inner edge of the grooves  886 ,  890  in the first C-shaped portion  876  and the second C-shaped portion  878  of the interrupted end cap  874  of the outer housing cylinder  862  of the stator  106   a  as illustrated in  FIG.  24   . 
     In the illustrated example, the power leaf spring contacts  843  (see  FIGS.  17 ,  23  and  24   ) are configured to be located between the inner housing  836  and the outer housing  834  of the stator  106   a . The power leaf spring contacts  843  each include a central flat portion  902 , a pair of contact leaf springs  904  at a first edge of the central flat portion  902  and an U-shaped connecter  906  at the second edge of the central flat portion  902 . As illustrated in  FIG.  17   , the central flat portions  902  of the power leaf spring contacts  843  are received within the power leaf spring contact channels  841  of the inner housing cylinder  838 . The pair of contact leaf springs  904  of the power leaf spring contacts  843  extend through the radial opening  851  to contact the contact rings  813  as illustrated in  FIGS.  16  and  17   . An interior surface of the outer housing cylinder  862  includes a plurality of axially extending projections  910  (see  FIG.  22   ) for holding the central flat portion  902  of the power leaf spring contacts  843  in place within the power leaf spring contact channels  841  when the inner housing  836  is inserted into the outer housing  834 . The U-shaped connecter  906  of the power leaf spring contacts  843  is located in the radially and axially open side  845  of the power leaf spring contact channels  841  and the axial openings  882  of the outer housing cylinder  862 . 
     The illustrated inner housing  836  of the stator  106   a  is fixed in position within the outer housing  834  of the stator  106   a . As illustrated in  FIGS.  16 - 18   , the data leaf spring contacts  842  are positioned within the data leaf spring contact channels  840  of the inner housing cylinder  838  and the power leaf spring contacts  843  are positioned within the power leaf spring contact channels  841  of the inner housing cylinder  838 . The inner housing  836  of the stator  106   a  is then inserted into the outer housing  834  of the stator  106   a  to form the stator  106   a . The interrupted end cap  874  at the closed end  866  of the outer housing cylinder  862  helps to ensure that the inner housing  836  of the stator  106   a  is properly orientated in the outer housing  834 . Furthermore, as illustrated in  FIG.  17   , a pin  912  can be inserted through the outer housing  834  and into the inner housing  836  (or into one of the channels  840 ,  841  (as shown)) to prevent relative rotation of the outer housing  834  and the inner housing  836 . It is contemplated that the outer housing  834  and the inner housing  836  could be fixed in relative position in any manner. 
     In the illustrated example, the main rotor  802  of the rotor  114   a  is fixedly, but rotatably, connected to the stator  106   a . The main rotor  802  is connected to the stator  106   a  by first inserting the small insertion tube  808  of the stepped tube  806  of the main rotor  802  into the inner housing  836  of the stator  106   a . As illustrated in  FIG.  17   , the insertion end  816  of the small insertion tube section  810  has an internal annular shelf  914  surrounding the axial opening  814  in the main rotor  802 . The internal section  858  of the central tube  854  of the inner housing cylinder  838  is inserted into the internal annular shelf  914  to locate the main rotor  802  in the stator  106   a  and is employed as a bearing during rotation of the main rotor  802  within the stator  106   a . After the main rotor  802  is fully inserted into the stator  106   a , the locking members  822  are inserted through the slots  868  in the outer housing cylinder  862  and into the groove  820  in the stepped section  812  of the stepped tube  806  of the main rotor  802 . As illustrated in  FIG.  18   , the locking members  822  have ramped projections  916  that allow the locking members  822  to be inserted into the slots  868 , but that lock the locking members  822  into the slots  868  when fully inserted into the slots  868 . As illustrated in  FIG.  17   , the main rotor receiving end  835  of the inner housing cylinder  838  of the inner housing  836  abuts the first radial abutment face  826  of the stepped section  812  of the stepped tube  806  of the main rotor  802  and the receiving end  864  of the outer housing cylinder  862  of the outer housing  834  abuts the second radial abutment face  828  of the stepped section  812  of the stepped tube  806  of the main rotor  802  when the main rotor  802  is fully inserted into the stator  106   a . The data wires of the wiring in the arms  12   a  are connected to the L-shaped connectors  896  of the power leaf spring contacts  843  and the stator  106   a  with the main rotor  802  connected thereto are then fixed to one of the arms  12   a  (after a first optical connector  918  is inserted into the stator  106   a  with the main rotor  802  connected thereto) to prepare for assembly of the suspension arm assembly  10   a.    
     The illustrated stator  106   a  with the main rotor  802  connected thereto includes the first optical connector  918  ( FIGS.  26 - 29   ) that connects to the fiber optic cable of the wiring in the arm  12   a  and that allows (with a second optical connector  920 ) the optical signal to be transmitted through the separable infinite rotation fiber optic and slip ring joint  800 . The first optical connector  918  includes a main holding tube  922  for holding the fiber optic cable  924  comprising a jacket  926  and a fiber optic  928 . The main holding tube  922  includes an insertion end  921 , a holding end  923  and an interior aperture  930  having the fiber optic cable  924  therein (shown with a truncated fiber optic cable  924  in  FIG.  29   , but not shown in  FIG.  28   ). The interior aperture  930  includes a larger section  932  and a smaller section  934 , with a step  936  between the larger section  932  and the smaller section  934 . 
     In the illustrated example, the first optical connector  918  includes a first distance adjustment assembly  919  at the insertion end  921  thereof. The first distance adjustment assembly  919  provides for differences in distances between the main rotor  802  and the rotor connector  804  when connected as discussed in more detail below. The first distance adjustment assembly  919  includes a coil spring  938 , a holding sleeve  940 , a lock ring  962 , an extension tube  966 , an abutment sleeve  969  and an optic end holder  971 . 
     The illustrated holding sleeve  940  of the first distance adjustment assembly  919  holds the first distance adjustment assembly  919  on the main holding tube  922 . As illustrated in  FIG.  29   , the holding sleeve  940  includes an axially extending hole  948  with an internal surface  949 . The internal surface  949  has, moving toward the main holding tube  922 , a first area  950  with a first diameter, a second area  952  with a second diameter, a ramp  954  leading to a third area  956  with a third diameter and a fourth area  958  having a fourth diameter. The third diameter is the largest diameter and the first diameter is the smallest diameter. The second diameter is between the first diameter and the fourth diameter and the fourth diameter is between the third diameter and the second diameter. 
     In the illustrated example, the holding sleeve  940  surrounds the insertion end  921  of the main holding tube  922  and is connected thereto. As illustrated in  FIGS.  27 - 29   , an exterior surface of the main holding tube  922  includes a recessed circumferential area  942  adjacent the insertion end  921  and a radially extending lip  944  at the terminal end of the insertion end  921 . The holding sleeve  940  is located on the recessed circumferential area  942 . The fourth area  958  of the internal surface  949  of the hole  948  of the holding sleeve  940  locks into a slot  960  in the recessed circumferential area  942  of the main holding tube  922  adjacent the radially extending lip  944 . Moreover, the radially extending lip  944  extends into the third area  956  of the internal surface  949  of the hole  948  of the holding sleeve  940  to lock the holding sleeve  940  to the main holding tube  922 . 
     As illustrated in  FIG.  29   , the lock ring  962  is located between the insertion end  921  of the main holding tube  922  and a step  964  between the first area  950  and the second area  952  of the internal surface  949  of the hole  948  of the holding sleeve  940 . The lock ring  962  locks the extension tube  966  within the holding sleeve  940 . The extension tube  966  is configured to slide within the interior aperture  930  of the main holding tube  922  at the insertion end  921  thereof and to also slide within the first area  950  of the internal surface  949  of the hole  948  of the holding sleeve  940 . The extension tube  966  includes a circumferential recess  968  in an outer surface  970  thereof. The circumferential recess  968  includes an inner side edge  972  and an outer side edge  974 . As illustrated in  FIG.  29   , the lock ring  962  extends into the circumferential recess  968  in the outer surface  970  of the extension tube  966 . The extension tube  966  is allowed to slide within the main holding tube  922  and the holding sleeve  940  between a fully extended position wherein the lock ring  962  abuts the inner side edge  972  of the circumferential recess  968  and a fully retracted position (shown in  FIG.  29   ) wherein the lock ring  962  abuts the outer side edge  974  of the circumferential recess  968 . The abutment sleeve  969  surrounds the extension tube  966  and can also limit movement of the extension tube  966  relative to the main holding tube  922 . It is contemplated that the abutment sleeve  969  can be made of any material. For example, the abutment sleeve  969  could be made of metal or of a ceramic material. 
     In the illustrated example, the coil spring  938  of the first distance adjustment assembly  919  is configured to move a portion of the first distance adjustment assembly  919  relative to the main holding tube  922 . As illustrated in  FIGS.  28  and  29   , the coil spring  938  is located at the insertion end  921  of the main holding tube  922  and within the smaller section  934  of the interior aperture  930 . A first end of the coil spring  938  abuts the step  936  between the larger section  932  and the smaller section  934  of the interior aperture  930 . A second end of the coil spring  938  abuts the extension tube  966  and biases the extension tube  966  to the fully extended position. 
     The illustrated optic end holder  971  is located within the extension tube  966  opposite the coil spring  938  and holds a terminal end of the fiber optic cable  924 . The optic end holder  971  includes an outer surface  978  engaged with an inner surface  976  of the extension tube  966 . As illustrated in  FIG.  27 - 29   , a circumferential flange  980  extends radially outward from an end of the optic end holder  971 . The circumferential flange  980  prevents the optic end holder  971  from sliding further into the extension tube  966 . The optic end holder  971  has an axial aperture  983  with a stepped surface  984 . Starting from within the extension tube  966 , the stepped surface  984  includes a widest diameter area  987  receiving the fiber optic cable  924 , with the widest diameter area  987  holding the jacket  926  of the fiber optic cable  924 . The stepped surface  984  then has a middle diameter area  989  holding only the fiber optic  928  without the jacket  926 . The stepped surface  984  then has a smallest diameter area  991  that is open. Light leaving the fiber optic travels through the axial aperture  983  within the stepped surface  984  at the smallest diameter area  991 . It is contemplated that the smallest diameter area  991  could have a very short axial length such that the fiber optic  928  is very near or even at an end of the optic end holder  971 . The optic end holder  971  includes an abutment end surface  992  outside of the smallest diameter area  991 . As described in more detail below, the abutment end surface  992  is configured to abut or be very close to the second optical connector  920 . 
     In the illustrated example, the first optical connector  918  includes a wiring connector  982  connected to the holding end  923  of the main holding tube  922 . The wiring connector  982  includes a tube  985  having an outside radially extending flange  986  dividing the wiring connector  982  into a wiring connection end  988  and a holding tube connection end  990 . The wiring connection end  988  of the wiring connector  982  surrounds an outside of the fiber optic cable  924  and allows the fiber optic cable  924  to slide therein if needed for movement of the fiber optic cable  924  as outlined below. It is contemplated that instead of having the fiber optic cable  924  pass through the tube  985 , the wiring connection end can be any connector for connecting to a fiber optic cable (e.g., a SC, LC, FC, ST, SMA or pigtail type connector). The holding tube connection end  990  of the wiring connector  982  surrounds and is received within a first recessed area  993  at the holding end  923  of the main holding tube  922 . A tube clip  994  surrounds the holding tube connection end  990  of the wiring connector  982  and a second recessed area  996  adjacent the first recessed area  993 . The tube clip  994  includes a pair of extending spring ears  998  for fixing the first optical connector  918  within the stator  106   a.    
     As illustrated in  FIG.  26   , the first optical connector  918  is connected to the stator  106   a  by inserting the first optical connector  918  into the central tube  854  of the inner housing  836  of the stator  106   a , with the optic end holder  971  being inserted first into the central tube  854 . As the first optical connector  918  is inserted into the central tube  854  of the inner housing  836  of the stator  106   a , the extending spring ears  998  of the tube clip  994  will be depressed toward the second recessed area  996  of the main holding tube  922  by an interior surface  1000  of the central tube  854 . As illustrated in  FIG.  16   , when the first optical connector  918  is fully inserted into the central tube  854  of the inner housing  836  of the stator  106   a , the spring ears  998  will expand outward into recesses  1002  in the interior surface  1000  of the central tube  854  to positively lock the first optical connector  918  into the central tube  854  of the inner housing  836  of the stator  106   a  and prevent removal of the first optical connector  918  from the stator  106   a.    
     As outlined above, the separable infinite rotation fiber optic and slip ring joint  800  includes the two-part separable rotor  114   a , with the rotor connector  804  removably connected to the main rotor  802 . The rotor connector  804  includes an insertion cylinder  1004  configured to be inserted into the main rotor  802  and an enlarged head  1006  at an end of the insertion cylinder  1004 . The rotor connector  804  includes a stepped central aperture  1008  and a plurality of wiring openings  1010  parallel with and surrounding the stepped central aperture  1008 . Each of the wiring openings  1010  is configured to receive one of the extension pins  832  of the main rotor  802  therein. Each of the wiring openings  1010  that receive an extension pin  832  that conducts power has a conducting tube  1012  therein as illustrated in  FIG.  17   . Each conducting tube  1012  includes a female receiving side  1014  for receiving one of the extension pins  832  of the main rotor  802  and a male side  1016  extending into the enlarged head  1006 , with the male side  1016  configured to be inserted into a wiring connector as is well known to those skilled in the art. The wiring openings  1010  that receive the extension pins  832  that conduct data each have a conducting connector  1018  therein as illustrated in  FIG.  32   . Each of the conducting connectors  1018  has a pair of opposite female receptacles for receiving pins therein for transmitting data as is well known to those skilled in the art. 
     In the illustrated example, the rotor connector  804  is connected to the main rotor  802  by inserting the insertion cylinder  1004  into the axial counterbore  824  of the large outer tube section  810  of the main rotor  802 . As illustrated in  FIG.  17   , the main rotor  802  includes an alignment cylinder  1020  extending into the axial counterbore  824  and surrounding the axial opening  814  in the main rotor  802 . The alignment cylinder  1020  is received within a largest area  1022  of the stepped central aperture  1008  of the rotor connector  804 . An inner surface  1024  of the axial counterbore  824  can include one or more alignment flanges  1026  (see  FIG.  18   ) configured to be received within axial slots  1028  on an outer surface of the insertion cylinder  1004  of the rotor connector  804  for properly aligning the rotor connector  804  within the main rotor  802 . As illustrated in  FIG.  19   , a floor  1030  of the axial counterbore  824  can also include ridges  1032  configured to be received in channels  1031  in a bottom of the insertion cylinder  1004  for properly aligning the rotor connector  804  within the main rotor  802 . Some of the ridges  1032  can include enlarged sections  1034  to further ensure proper rotational alignment of the insertion cylinder  1004  to ensure that the proper data and power lines are not mixed up. As illustrated in  FIG.  14   , the head  1006  can have a radially extending hole  999  configured to receive a fastener therein for fixing the rotor connector  804  in positon within one of the arms  12   a.    
     The illustrated rotor connector  804  includes the second optical connector  920  ( FIGS.  31  and  33 - 35   ) that connects to the fiber optic cable of the wiring in the arm  12   a  and that allows (with the first optical connector  918 ) the optical signal to be transmitted through the separable infinite rotation fiber optic and slip ring joint  800 . The second optical connector  920  includes a holding tube  1050  for holding a fiber optic cable  1052  comprising a jacket  1054  and a fiber optic  1056 . The holding tube  1050  includes an insertion end  1058 , a holding end  1060  and an interior aperture  1062  having the fiber optic cable  1052  therein (shown with a truncated fiber optic cable  1052  in  FIG.  34   ). A stepped sleeve  1064  is fixed to an exterior surface  1066  of the holding tube  1050 . The stepped sleeve  1064  includes a lower step  1068  at the insertion end  1058  and a higher step  1070  at the holding end  1060 . As illustrated in  FIG.  35   , the higher step  1070  includes an axial slot  1072  to assist in sliding of the holding tube  1050  without rotation thereof. 
     In the illustrated example, the second optical connector  920  includes a second distance adjustment assembly  1074  at the insertion end  1062  thereof. The second distance adjustment assembly  1074  provides for differences in distances between the main rotor  802  and the rotor connector  804  when connected as discussed in more detail below. The second distance adjustment assembly  1074  includes a coil spring  1076 , a washer  1078 , a wiring connector  1080 , a sliding sleeve  1082  and an abutment sleeve  1086  all held within a clip sleeve  1084 . 
     The illustrated clip sleeve  1084  holds the holding tube  1050 , the stepped sleeve  1064 , the coil spring  1076 , the washer  1078 , the wiring connector  1080 , the sliding sleeve  1082  and the abutment sleeve  1086 . The clip sleeve  1084  includes a tube  1088  having a pair of extending spring ears  1090  for fixing the second optical connector  920  within the rotor connector  804  as discussed in more detail below. The wiring connector  1080  is received within a first end of the clip sleeve  1084 . The wiring connector  1080  includes a tube  1092  having an outside radially extending flange  1094  dividing the wiring connector  1080  into a wiring connection end  1096  and a sleeve connection end  1098 . The wiring connection end  1096  of the wiring connector  1080  surrounds an outside of the fiber optic cable  1052  and allows the fiber optic cable  1052  to slide therein if needed for movement of the fiber optic cable  1052  as outlined below. It is contemplated that instead of having the fiber optic cable  1052  pass through the tube  1092 , the wiring connection end can be any connector for connecting to a fiber optic cable (e.g., a SC, LC, FC, ST, SMA or pigtail type connector). The sleeve connection end  1098  of the wiring connector  1080  is surrounded by the clip sleeve  1084 . As illustrated in  FIG.  33   , the sleeve connection end  1098  of the wiring connector  1080  includes radially extending ramped tabs  1099  that are inserted into first openings  1100  in the clip sleeve  1084  to connect the wiring connector  1080  to the clip sleeve  1084 . 
     In the illustrated example, the coil spring  1076  pushes against the washer  1078  to move the holding tube  1050 . As illustrated in  FIGS.  34  and  35   , the washer  1078  is located at (and can be connected to) the holding end  1060  of the holding tube  1050 . One end of the coil spring  1076  pushes against the washer  1078 . Another end of the coil spring  1076  abuts against an end rim  1102  of the sleeve connection end  1098  of the tube  1092  of the wiring connector  1080 . The abutment sleeve  1086  surrounds and is fixed to the holding tube  1050  at the insertion end  1058  thereof. The abutment sleeve  1086  includes an abutment rim  1104  opposite the holding tube  1050 . When the abutment rim  1104  is pushed, the abutment sleeve  1086  and thereby the holding tube  1050  and the washer  1078  are pushed against the bias of the coil spring  1076 . 
     The illustrated sliding sleeve  1082  surrounds the abutment sleeve  1086  and the holding tube  1050  is allowed to slide within the sliding sleeve  1082 . The sliding sleeve  1082  includes an outer surface  1106  with a pair of ramped tabs  1108 . The sliding sleeve  1082  is inserted into the clip sleeve  1084  and the ramped tabs  1108  are inserted into second openings  1110  in the clip sleeve  1084  to connect the sliding sleeve  1082  to the clip sleeve  1084 . The sliding sleeve  1082  includes radially extending projections  1112  that slide within the axial slots  1072  in the higher step  1070  of the stepped sleeve  1064  to assist in sliding of the holding tube  1050  without rotation thereof. Engagement of the sliding sleeve  1082  and the stepped sleeve  1064  also can limit axial movement of the stepped sleeve  1064  and the holding tube  1050  connected thereto. 
     The illustrated holding tube  1050  includes an optic end holder  1114  located within the interior aperture  1062  thereof opposite the coil spring  1076 . The optic end holder  1114  holds a terminal end of the fiber optic cable  1052 . The optic end holder  1114  includes an outer surface  1116  engaged with an inner surface  1118  of the holding tube  1050 . The optic end holder  1114  has an axial aperture  1120  with a stepped surface  1122 . Starting from within the holding tube  1050 , the stepped surface  1122  includes a widest diameter area  1124  receiving the fiber optic cable  1052 , with the widest diameter area  1124  holding the jacket  1054  of the fiber optic cable  1052 . The stepped surface  1122  then has a middle diameter area  1126  holding only the fiber optic  1056  without the jacket  1054 . The stepped surface  1122  then has a smallest diameter area  1128  that is open. Light leaving the fiber optic travels through the axial aperture  1120  within the stepped surface  1122  at the smallest diameter area  1128 . It is contemplated that the smallest diameter area  1128  could have a very short axial length such that the fiber optic  1056  is very near or even at an end of the optic end holder  1114 . The optic end holder  1114  includes an abutment end surface  1130  outside of the smallest diameter area  1128 . As described in more detail below, the abutment end surface  1130  is configured to abut or be very close to the first optical connector  918 . 
     As illustrated in  FIG.  31   , the second optical connector  920  is connected to the rotor connector  804  by inserting the second optical connector  920  into the stepped central aperture  1008  of the rotor connector  804 , with the abutment sleeve  1086  being inserted first into the stepped central aperture  1008 . As the second optical connector  920  is inserted into the stepped central aperture  1008  of the rotor connector  804 , the extending spring ears  1090  of the clip sleeve  1084  will be depressed inward by an interior surface  1132  of the stepped central aperture  1008 . As illustrated in  FIG.  16   , when the second optical connector  920  is fully inserted into the stepped central aperture  1008  of the rotor connector  804 , the spring ears  1090  will expand outward into recesses  1136  in the interior surface  1132  of the stepped central aperture  1008  to positively lock the second optical connector  920  into the stepped central aperture  1008  of the rotor connector  804  and prevent removal of the second optical connector  920  from the rotor connector  804 . 
     In the illustrated example, the construction of the separable infinite rotation fiber optic and slip ring joint  800  allows for variation in distances between the main rotor  802  and the rotor connector  804  during assembly of the suspension arm assembly  10   a . In the illustrated example, the rotor connector  804  is inserted into the main rotor  802  when the adjacent arms  12   a  or an arm  12   a  and either the ceiling attachment member  24   a  or the display support assembly  18   a  are connected together. In the illustrated main rotor  802 , the extension pins  832  are very long and do not need to be fully inserted into the wiring openings  1010  of the rotor connector  804  to be able to transmit power and data. Therefore, if assembly of the suspension arm assembly  10   a  results in the rotor connector  804  not being fully inserted into the main rotor  802 , the suspension arm assembly  10   a  can still transmit power and data through the rotary joints thereof. 
     The illustrated suspension arm assembly  10   a  also accommodates distances between the rotor connector  804  and the main rotor  802  for transmitting information over the fiber optic cables  924 ,  1052  through adjustments of the first optical connector  918  and the second optical connector  920 . As illustrated in  FIG.  36   , when the rotor connector  804  is engaged with the main rotor  802 , the coil spring  938  in the first optical connector  918  will bias the optic end holder  971  in the first optical connector  918  toward the second optical connector  920 . Likewise, the coil spring  1076  in the second optical connector  920  will bias the optic end holder  1114  in the second optical connector  920  toward the first optical connector  918 . The abutment sleeve  969  of the first optical connector  918  will abut against abutment rim  1104  of the abutment sleeve  1086  of the second optical connector  920  to maintain a desired distance between the optic end holder  971  in the first optical connector  918  and the second optical connector  920  toward the first optical connector  918 . It is contemplated that the optic end holder  971  in the first optical connector  918  and the optic end holder  1114  in the second optical connector  920  could abut each other or could be spaced. Furthermore, it is contemplated that the optic end holder  971  in the first optical connector  918  and the optic end holder  1114  in the second optical connector  920  could have a limited range of motion (e.g., up to 2 mm). The first optical connector  918  and the second optical connector  920  thereby ensure that the optic end holder  971  in the first optical connector  918  and the optic end holder  1114  in the second optical connector  920  are sufficiently close to transmit optical signals across the separable infinite rotation fiber optic and slip ring joint  800  without significant loss of information. 
     In the illustrated example, the separable infinite rotation fiber optic and slip ring joint  800  can easily be connected during assembly of the arms  12   a  holding each portion of the separable infinite rotation fiber optic and slip ring joint  800 . Many of the features of the separable infinite rotation fiber optic and slip ring joint  800  allow for easy assembly and can be used to blind mate the separate portions of the separable infinite rotation fiber optic and slip ring joint  800 . For example, the separate portions of the separable infinite rotation fiber optic and slip ring joint  800  can be gatherable to allow for the separate portions to gather and align during mating.  FIGS.  16 - 18 ,  30  and  36    illustrate an example of a gatherable feature of the separable infinite rotation fiber optic and slip ring joint  800 . As illustrated in  FIGS.  16 - 18 ,  30  and  36   , the edge of the large outer tube section  810  of the stepped tube  806  of the main rotor  802  includes an inwardly extending and circular beveled surface  1500 . Likewise, the insertion cylinder  1004  of the rotor connector  804  includes an edge having an outwardly extending and circular beveled surface  1502 . The inwardly extending and circular beveled surface  1500  and the outwardly extending and circular beveled surface  1502  are configured to abut and center the main rotor  802  as the rotor connector  804  is inserted into the main rotor  802 . The axial slots  1028  on the insertion cylinder  1004  of the rotor connector  804  and the alignment flanges  1026  on the inner surface  1024  of the axial counterbore  824  of the large outer tube section  810  of the stepped tube  806  of the main rotor  802  can also assist in mating the separate portions of the separable infinite rotation fiber optic and slip ring joint  800 . It is contemplated that further angled surfaces between the main rotor  802  and the rotor connector  804  can function as a funnel to rotate one of the main rotor  802  and the rotor connector  804  as they are pressed together to properly align the main rotor  802  and the rotor connector  804 . 
     Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.