A door closer includes a housing, a spindle carried in the housing, being exposed at a top side and a bottom side of the housing and arranged to rotate about an axis relative to the housing, and a passage through the spindle comprising a passage through the housing. The passage provides a means for wires or other conduits to pass from the door frame into the door, without being exposed outside of the door frame and door.

BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to door closers, and particularly door closers that attach to the door via a rotatable spindle.  
         [0002]     Door closers are well known, including door closers wherein the door closer attaches to the door via a rotatable spindle.  
         [0003]     In some situations, electrical power, or conduits for other signal transmissions or provision of fluids, such as water, need to be extended from a wall or door frame to the door itself, which requires lines extending outside the door and door frame that may become twisted or overworked as the door pivots repeatedly between an open and closed position. It is known to provide access through a hollow hinge for a conduit or wires, to extend from a cabinet into a door, such as in a refrigerator door, however, even in such a situation, the wires or conduit must exit the cabinet to enter into the hinge, since the hinge pin area is exposed on the exterior of the door and cabinet.  
         [0004]     In the situation of a door, such as a door for a house or office, in order to have the conduit or wire extend from the door frame or wall into the hinge, the conduit or wire would be required to exit out of the door frame or hinge, causing an unsightly condition, and subjecting the wire or conduit to twisting or other mechanical wear.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides a door closer comprising a housing, a spindle carried in the housing, being exposed at a top side and a bottom side of the housing and arranged to rotate about an axis relative to the housing, and a passage through the spindle comprising a passage through the housing.  
         [0006]     In an embodiment, the passage is coaxial with the axis.  
         [0007]     In an embodiment, the housing is filled with hydraulic fluid.  
         [0008]     In an embodiment, a seal member is arranged between the rotatable spindle and the housing adjacent to a point in the housing where the spindle is exposed.  
         [0009]     In an embodiment, the spindle protrudes from at least one of the top and bottom sides.  
         [0010]     In an embodiment, the spindle is flush with at least one of the top and bottom sides.  
         [0011]     In an embodiment, the spindle has a first end and a second end and the housing comprises a cast body and a removable cover plate, with the spindle extending through the casting at one of the ends and through the removable cover plate at the other of the ends.  
         [0012]     In an embodiment, the invention provides a door closer comprising a housing having a top face and a bottom face, a spindle rotatably mounted in the housing for connecting the closer to a door, the spindle being exposed at a first end at the top face and at a second end at the bottom face, a cylinder formed interiorly of the housing, a piston operable in the housing,  
         [0013]     a cam and cam follower arrangement interconnecting the piston and the spindle for movement of the piston upon rotation of the spindle, and a passage extending through the spindle from the first end to the second end.  
         [0014]     In an embodiment, the invention provides a door closer comprising a housing having a top face and a bottom face, a spindle rotatably mounted in the housing for connecting the closer to a door, the spindle being exposed at a first end at the top face and at a second end at the bottom face, a cylinder formed interiorly of the housing, a piston operable in the cylinder, a carrier plate connected to the piston and slidably mounted within the housing about the spindle, a cam follower carried by the plate, a cam carried by the spindle to rotate with the spindle, the cam having a cam surface engageable with the cam follower to cause the plate to slide within the housing upon rotation of the cam, a spring member adapted to be compressed upon rotation of the spindle in a door opening direction and as the plate slides towards the cylinder and to bias the plate in a direction away from the cylinder.  
         [0015]     These and other features and advantages of the present invention will become apparent upon a reading of the detailed description and a review of the accompanying drawings. Specific embodiments of the present invention are described herein. The present invention is not intended to be limited to only these embodiments. Changes and modifications can be made to the described embodiments and yet fall within the scope of the present invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0016]      FIG. 1  is a plan view of a door closer connected to a door and a door frame.  
         [0017]      FIG. 2  is a bottom view of the door closer of  FIG. 1  with a portion of the housing removed to illustrate the general components of the closer mechanism.  
         [0018]      FIG. 3  is a partial side sectional view of the door closer housing, with some components removed for clarity. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]      FIGS. 1 and 2  generally illustrate a door closer mechanism for which the present invention is particularly useful. Many different constructions of door closer mechanisms may incorporate the present invention, such as those disclosed in U.S. Pat. Nos. 6,397,430, 6,260,236, 5,829,097, 5,802,670, 5,666,692, 5,050,268, the disclosures of each of which are incorporated herein by reference.  
         [0020]      FIG. 1  illustrates a top plan view of a door closer  10  mounted in the transom above the door overhead or lintel  14  and connected by a closing lever  16  to a slide rail  18  that is mounted to a door  20 . The door  20  pivots about hinges  22  from an open position as illustrated to a closed position shown in phantom view in  FIG. 1 . Alternately, the door closer  10  can be mounted to the door  20  and an appropriate lever structure can connect the door closer to a sliding attachment mounted to the door overhead or lintel, although this construction is not shown in the drawings.  
         [0021]      FIG. 2  shows the door closer  10  in bottom view. A cover  26  is partially removed to expose the components within the closer. Two pistons  30  and  32  are closely confined within respective cylinders  34  and  36  within a cylinder head portion  80  of a housing  40  of the closer mechanism  10 . The cylinders  34  and  36  are closed by caps  38  and  39  respectively. The pistons  30  and  32  are connected to reciprocable rods  42  and  44  respectively. The rods  42  and  44  pass through apertures  42   a  and  44   a  through a compression plate  46  which is movable within the housing  40 . A first spring  48  and a second spring  50  are located between the compression plate  46  and the pistons  30  and  32 , respectively. An adjusting screw  54  is connected to the compression plate  46  and when turned about its axis will move the compression plate longitudinally within the housing  40 . By doing so, the spring tension can be altered in order to change the closing force characteristics.  
         [0022]     The rods  42  and  44  are connected by screws  60  to a cam chassis  62  including a pair of cam plates  66  that are connected to and sandwich therebetween a cam  68  ( FIG. 3 ) which is further connected to co-rotate with a spindle  72  extending downwardly through the housing  40 .  
         [0023]     The spindle  72  may be connected to the door  20  either by means of the closing lever  16  or directly, such that the door pivots about a rotational axis of the spindle.  
         [0024]     Upon rotation of the spindle  72  by rotation of the door  20 , the cam  68  forces the chassis  62  to move or slide longitudinally within the housing  40 . The position illustrated in  FIG. 2  corresponds to a door closed position. Upon rotation of the spindle  72 , the chassis  62  moves in a direction towards the right within the housing  40 , as viewed in  FIG. 2 . This movement drives the pistons  30  and  32  in a door opening stroke within the housing  40  which further compresses the springs  48  and  50  against the compression plate  46 .  
         [0025]     When the pistons  30  and  32  are forced to the left in  FIG. 2 , oil, such as hydraulic oil, or another viscous fluid that is held within the housing  40  is compressed by the movement of the pistons. The fluid under pressure is forced from backsides  30   a  and  32   a  of the pistons  30  and  32 , respectively, through a series of valves and passageways, within the cylinders  34  and  36 . Particular design details of the passageways and valves and the adjustment of the screw  54  can significantly alter the characteristics of the door closer  10  in both the opening and closing cycles as is known. The general door closer  10  described and illustrated in  FIGS. 1 and 2  is provided herein for illustrating the present invention. The door closer construction can change considerably and yet fall within the scope of the present invention. Additionally, the adjustment screw  54  and compression plate  46  can be eliminated and yet the door closer  10  can fall within the scope of the invention.  
         [0026]      FIG. 3  illustrates a partial side sectional view of the door closer  10  showing the exterior housing  40  and a removable cover plate  100 . The spindle  72  is rotatably mounted in the housing  40  so as to rotate about an axis  102 . The spindle  72  is exposed at a first end  104  at a top side  106  of the housing and is exposed at a second end  108  at a bottom side  110  of the housing. A passage  112  extends through the spindle  72  comprising a passage through the housing  40 . In an embodiment of the invention, the passage  112  is coaxial with the axis of rotation  102  of the spindle  72 .  
         [0027]     In an embodiment, particularly where the housing  40  is filled with a viscous fluid, a seal member  114  is arranged between the rotatable spindle  72  and the housing adjacent to a point in the housing where the spindle is exposed. Specifically, the housing  40  may have a hole  116  in the bottom side  110  with a first seal member  114  positioned on an inside seat  118  surrounding the hole  116 . The removable cover plate  100  may have a hole  120  which is at the top side  106  of the housing  40 , with a second seal member  114  positioned on an inside seat  120  surrounding the hole  120 . The seal members  114  may comprise O-rings.  
         [0028]     The spindle  72  may protrude from at least one of the top  106  and bottom  110  sides, here shown protruding at the top side. The spindle  72  may be essentially flush with at least one of the top  106  and bottom  110  sides, here shown being flush with the bottom side.  
         [0029]     As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.