Abstract:
A self closing and adjustable closing force cam hinge includes a compression spring located on the hinge so that a hinge pin passes through the compression spring and the head of the hinge pin is retracted in a direction away from the compression spring to compress the compression spring. Compression of the spring applies a closing force to the hinge when the hinge is in the open position. The hinge also includes a spring adjuster having an adjustably positionable body that is adjustably positionable relative to the head of the hinge pin. Adjustment of the position of the adjustably positionable body raises or lowers the head of the hinge pin such that raising of the hinge pin increases compression of the compression spring to increase the closing force applied by the compression spring and lowering of the hinge decreases compression of the compression spring to decrease the closing force applied by the compression spring.

Description:
FIELD 
     This disclosure relates to the field of hinges. More particularly, this disclosure relates to a cam hinge having a spring with adjustable tension to provide an adjustable closing force. 
     BACKGROUND 
     Cam hinges or lift hinges are commonly used in indoor applications where there is a need to lift the door to overcome thresholds or the like obstacles at floor level, or when the floor below the door is inclined or sloped. Conventional cam springs desire improvement in many regards. 
     What is desired is a cam hinge that is configured to have spring-assisted closing as a feature. Also desired is a cam hinge with spring assisted closing, with adjustability of the spring tension so as to permit adjustment of the closure speed. 
     The present disclosure advantageously provides a cam hinge having spring assisted closing, with adjustability of the spring tension to provide adjustable closing speed. 
     SUMMARY 
     The above and other needs are met by a self-closing and adjustable closing force cam hinge. 
     In one aspect, the hinge includes a stationary hinge portion having a hinge body; a pivoting hinge portion having a hinge body; and a hinge pin having a head and passing through the hinge body of the stationary hinge portion and the hinge body of the pivoting hinge portion. The pivoting hinge portion pivots about the hinge pin relative to the stationary hinge portion and cooperates with the stationary hinge portion to enable the pivoting hinge portion to lift as the pivoting hinge portion is rotated from a closed position to an open position and to lower as the pivoting hinge portion is rotated from the open position to the closed position. 
     A compression spring is located on the hinge so that the hinge pin passes through the compression spring and the head of the hinge pin is retracted from the compression spring to compress the compression spring so that the compression spring applies a closing force to the hinge when the hinge is in the open position. A spring adjuster includes an adjustably positionable body that is adjustably positionable relative to the head of the hinge pin. 
     Adjustment of the position of the adjustably positionable body raises or lowers the head of the hinge pin such that raising of the hinge pin increases compression of the compression spring to increase the closing force applied by the compression spring and lowering of the hinge decreases compression of the compression spring to decrease the closing force applied by the compression spring. 
     In another aspect, a self closing and adjustable closing force hinge includes a hinge openable and closeable between an open position and a closed position. The hinge has a compression spring located on the hinge so that a hinge pin passes through the compression spring and a head of the hinge pin is retracted in a direction away from the compression spring to compress the compression spring. The compression spring applies a closing force to the hinge when the hinge is in an open position. 
     A spring adjuster is located on the hinge and includes an adjustably positionable body that is adjustably positionable relative to the head of the hinge pin. Adjustment of the position of the adjustably positionable body raises or lowers the head of the hinge pin. Raising of the hinge pin increases compression of the compression spring to increase the closing force applied by the compression spring and lowering of the hinge decreases compression of the compression spring to decrease the closing force applied by the compression spring. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages of the disclosure are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
         FIG. 1  is a side view of a cam hinge according to the disclosure with the hinge in a position corresponding to a gate supported by the hinge being in a fully closed position. 
         FIG. 2  is a perspective view of a cam hinge according to the disclosure with the hinge in a position corresponding to a gate supported by the hinge being in a fully open position. 
         FIG. 3  is a cross-sectional view of hinge body portions of the hinge of  FIG. 1  with a spring adjustment system thereof adjusted to slightly tension a spring component thereof to provide a relatively light closing force. 
         FIG. 4  is a cross-sectional view of hinge body portions of the hinge of  FIG. 1  with a spring adjustment system thereof adjusted to increase tension of the spring component thereof to provide a stronger closing force. 
         FIG. 5  is a close-up view of an upper portion of the cam hinge of  FIG. 1  showing a spring adjustment components of the cam hinge cooperating with one another to slightly tension the spring component to provide a relatively light closing force. 
         FIG. 6  is a close-up view of an upper portion of the cam hinge of  FIG. 1  showing a spring adjustment components of the cam hinge cooperating with one another to tension the spring component to provide a relatively strong closing force. 
         FIG. 7  is an exploded perspective view of portions of the cam hinge of  FIG. 1 . 
         FIG. 8  shows a stationary hinge portion of the cam hinge of  FIG. 1 . 
         FIG. 9  shows a pivoting hinge portion of the cam hinge of  FIG. 1 . 
         FIG. 10  shows a stationary hinge portion of the cam hinge of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the drawings, the disclosure relates to a bi-directional cam hinge  10  configured to have spring assisted closing, with adjustability of the spring tension to provide adjustable closing speed. The hinge  10  is particularly suitable for use as a hinge for attaching a fence gate to a fence post, and particularly for a vinyl fence and gate. The hinge  10  is configured to function in either direction so that a gate can be opened either with clockwise or counter-clockwise rotation of the hinge  10 . However, but it will be understood that it could be configured to function for only one direction of rotation. 
     The hinge  10  includes a hinge pin  12 , a lower stationary hinge portion  14 , and an upper pivoting hinge portion  16 . The hinge  10  includes a compression spring  18  for spring assisted closing of the hinge  10 . 
     The hinge pin  12  is an elongate, preferably metal, pin having a shaft  20  with an enlarged head  22  at one end and a distal end  24  at the opposite end. The compression spring  18  is installed on the pin  12  adjacent the distal end  24  of the pin  12 . The distal end  24  may be tapered and includes a circumferential groove  26  for interfacing with a fastener, such as a retaining ring  28 , for retaining the compression spring  18 . As shown, a washer may be located between the end of the spring  18  and the retaining ring  28 . 
     The lower stationary hinge portion  14  includes an elongate generally planar base  30  for mounting the lower stationary hinge portion  14  adjacent to a fence post P or the like as by use of screws passed through apertures  32 . A hinge body  34  extends outwardly from the base  30 , and includes a central vertical bore  36  that extends through the hinge body  34  and is open at each end. A lower end  36   a  of the bore  36  has an enlarged diameter for receiving the compression spring  18 . An upper end  38  of the hinge body  34  is configured to receive a cam insert  40 . 
     The cam insert  40  is configured to sit on and nest with the upper end  38  of the hinge body and provide an exterior cam surface  42  with a through bore  44  aligned with the bore  36 . The cam insert  40  may include a key or projection  46  received by a corresponding lock or notch  48  on the hinge body  34  to secure the cam insert  40  to the hinge body  34  and inhibit relative movement thereof. In this regard, the cam insert  40  is configured as a separate piece to simplify manufacturing and reduce manufacturing costs. However, it will be understood that the hinge body  34  may be formed of one piece construction to include the cam surface  42 . 
     The upper pivoting hinge portion  16  includes an elongate generally planar base  60  for mounting the upper pivoting hinge portion  16  adjacent to a fence gate G or the like as by use of screws passed through apertures  62 . A hinge body  64  extends outwardly from the base  60 , and includes a central vertical bore  66  that extends through the hinge body  64  and is open at each end. An upper end  66   a  of the bore  66  has an enlarged diameter for receiving the head  22  of the hinge pin  12 . A lower end  68  of the hinge body  64  is rounded and otherwise configured to include a cam surface configured to cooperate with the cam surface  42  of the hinge body  34  to enable cam or lift hinge operation of the hinge  10 . 
     A guide  70  is located on the lower end  68  of the hinge body  64 . The guide  70  may be provided, for example, as by a pin or the like extending through an aperture  72  located adjacent the lower end  68  of the hinge body  64 . The guide  70  directly contacts the cam surface  42  to follow the contour thereof. For example, the cam surface  42  is a generally rounded and rising sloped surface, and the lower end  68  of the hinge body  64  is generally rounded and oppositely sloped so as to provide clearance as the hinge rotates as guided by the guide  70  traveling along the cam surface. 
     When the gate G is closed, the lower end  68  is at its lowest position. As the gate G is opened, either clockwise or counter clockwise, the guide  72 , and hence the lower end  68 , follows the contour of the cam surface  42  and the hinge body  64  rotates and rises relative to the hinge body  34 . As the gate is closed, this is reversed. The compression spring  18  provides a downward pull on the hinge body  64  via the head  22  of the hinge pin  12  bearing on the hinge body  64  to provide a closing force. 
     The guide  70  also functions to enable the gate G to resist the force of the compression spring  18  and remain in a fully open position, the hinge body  64 . The guide  70  cooperates with a notch  74  defined across an upper portion of the cam surface  42  so as to reside in the notch  74 . This enables the gate G to resist the force of the compression spring  18  and remain in a fully open position. To close the gate G, the user supplies a closing force that unseats the guide  70  from the notch  74 . 
     To enable adjustment of the closing force supplied by the compression spring  12 , the vertical position of the head  22  of the hinge pin  12  is adjusted by use of a set screw  80  threadably received by a threaded bore  82  of the hinge body  64  at a location proximate the head  22  of the hinge pin  12 . 
     With reference to  FIGS. 3 and 5 , the hinge  10  is shown with the compression spring  18  set to a minimum closing force. As will be seen, the set screw  80  is retracted substantially from the bore  82  so as to not engage the head  22  of the hinge pin  12 . Thus, the head  22  is able to fully seat into the upper end  66   a  of the bore  66 . This position of the pin  12  renders the compression spring  18  in a minimally compressed orientation to provide the weakest closing force. 
     Turning now to  FIGS. 4 and 6 , the hinge  10  is shown with the compression spring  18  set to a maximum closing force. As will be seen, the set screw  80  is fully inserted into the bore  82  as by clockwise rotation of the set screw  80  into the bore  82  so as to position the set screw  80  fully span and engage the underside of the head  22  of the hinge pin  12 . This relative positioning of the screw  80  and the head  22  serves to raise the pin  12 . The lower end of the compression spring  18  is engaged by the retaining ring  28  fixed on the distal end  24  of the pin  12  so that raising of the pin  12  compresses the compression spring  18  in the lower end  36   a  of the bore  36  of the hinge body  34 . This position of the pin  12  renders the compression spring  18  in a maximum compressed orientation so as to provide the strongest closing force. 
     The set screw  80  may be adjusted between the fully inserted and the retracted positions to enable incremental adjustment of the position of the head  22  of the pin  12  and hence incremental adjustment of the closing force of the spring  12 . That is, the lower surface of the head  22  of the pin  12  and the set screw  80  cooperate so that as the distal end of the set screw  80  initially contacts the head  22 , the head  22  is raised. As the set screw  80  is further screwed into the bore  80  it continues to span the lower side of the head  22  causing incremental rising of the head  22 , with maximum rising of the head  22  achieved when the set screw  80  fully spans the underside of the head  22 . 
     As will be appreciated, the described hinge  10  advantageously provides a cam hinge having spring assisted closing, with adjustability of the spring tension to provide adjustable closing speed. 
     The hinge  10  is particularly suitable for use as a hinge for attaching a fence gate to a fence post, and particularly for a vinyl fence and gate. In this regard, the components for the hinge  10  described above are generally formed of sturdy metal suitable for use as a hinge. However, to facilitate mounting to a vinyl post and a vinyl gate, the hinge  10  may further include mounting pads  90  and  92  configured to connect to and abut the bases  30  and  60 , respectively. The pads  90  and  92  are desirably formed of a vinyl material so that the bases  30  and  60  do not mar or dig into the pot or gate to which they are installed. Also, screw receivers  94  and  96  are located on the opposite surface of the post or gate from the bases  30  and  60 , respectively, for receiving the mounting screws or other fasteners. The screw receivers  94  and  96  are desirably formed of metal. 
     The foregoing description of preferred embodiments for this disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the disclosure as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.