BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a joint mechanism. More specifically, the present invention relates to an adjustable pivot joint apparatus having a releasable locking structure.  
           [0003]    2. General Background and State of the Art  
           [0004]    There are many examples of pivot joints in the marketplace today. Most existing products include two halves fastened together which pivot about a particular point. Some of these products include a locking mechanism which, when released, allows the pivot joint to move about a particular point. However, many pivot joints fail over time due to frequent twisting between the two half joints. Other pivot joints are heavy and expensive to manufacture.  
         INVENTION SUMMARY  
         [0005]    In one aspect of the present invention, a pivot joint includes a plate system having a first pair of joint plates, a first clutch plate, a second pair of joint plates, and a second clutch plate, the first and second clutch plates each having a grooved portion such that the first and second clutch plates are interlockable by engaging the grooved portions in each of the first and second clutch plates. The pivot joint also includes a spring mechanism positioned between the second clutch plate and one joint plate in the second pair of joint plates, and a pivot piece about which at least one joint plate in the first pair of joint plates and the first clutch plate are rotatable.  
           [0006]    In another aspect of the present invention, a pivot joint includes a plate mechanism having a first clutch plate and a second clutch plate capable of lockably engaging, each of the first and second clutch plates having an elevated portion with a plurality of grooves and a plurality of bars therein such that when the elevated portions of each of the first and second clutch plates are aligned together, the plurality of bars of one of the first and second clutch plates lockably engage with the plurality of grooves of the other of the first and second clutch plate. The pivot joint also includes a release mechanism having a series of pins configured to disengage the first clutch plate from the second clutch plate when the series of pins pushes the second clutch plate against a spring mechanism.  
           [0007]    In yet another aspect of the present invention, a method of pivoting a joint apparatus includes providing a plate system including a first pair of joint plates, a first clutch plate, a second pair of joint plates, and a second clutch plate, the first and second clutch plates each having grooved portions such that the first and second clutch plates are securable by interlocking the grooved portions in each of the first and second clutch plates. The method also includes releasing the first and second clutch plates by activating a series of pins to push the second clutch plate against a spring mechanism, rotating at least one joint plate in the first pair of joint plates around a pivot piece, and locking the first and second clutch plates in a desired position by deactivating the series of pins to release pressure on the spring mechanism and engage the grooved portions on the first and second clutch plates to prevent the first and second clutch plates from moving relative to each other.  
           [0008]    In still another aspect of the present invention, a method of pivoting a joint apparatus including providing a plate system having a pair of clutch plates each having grooved portions that allow the pair of clutch plates to interlock when interlocked together, releasing the pair clutch plates by activating a release mechanism to force the pair of clutch plates apart, rotating a first clutch plate in the pair of clutch plates about a pivot piece, and locking the pair of clutch plates in a desired position by deactivating the release mechanism allowing the grooved portions on the pair of clutch plates to engage each other and prevent the pair of clutch plates from moving relative to each other.  
           [0009]    It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only exemplary embodiments of the invention by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    Aspects of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying drawings wherein:  
         [0011]    [0011]FIG. 1 is a cross-sectional view of a pivot joint apparatus according to the present invention;  
         [0012]    [0012]FIG. 2 is a perspective view of particular plate components of the pivot joint apparatus of the present invention;  
         [0013]    [0013]FIG. 3 is a perspective view of the pivot joint apparatus of the present invention;  
         [0014]    [0014]FIG. 4 is a side view of the pivot joint apparatus of the present invention; and  
         [0015]    [0015]FIG. 5 is another side view of the pivot joint apparatus of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0016]    The detailed description set forth below in connection with the appended drawings is intended as a description of exemplary embodiments in which the present invention can be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.  
         [0017]    In an exemplary embodiment of the present invention, an adjustable pivot joint apparatus is provided having a plate system which includes interlocking clutch plates which, when separated, allow the apparatus to pivot about an axis. The apparatus also includes a release mechanism and a spring mechanism. The clutch plates prevent the apparatus from pivoting about the axis when in a locked position.  
         [0018]    [0018]FIG. 1 is a cross-sectional view of a pivot joint apparatus  10  according to the present invention. The pivot joint apparatus  10  of FIG. 1 is shown in an unlocked position. The pivot joint apparatus  10  includes a system of plates. The system of plates includes a first pair of joint plates  20  and a second pair of joint plates  30 . The system of plates also includes a first clutch plate  40  and a second clutch plate  50 . The first clutch plate  40  may be coupled to the first pair of joint plates  20 . The first and second clutch plates  40  and  50  may be substantially circular in shape. The first and second clutch plates  40  and  50  may be made of sheet metal or any other material of suitable strength.  
         [0019]    In one embodiment, each of the first and second clutch plates  40  and  50  may include an elevated portion  60 . The elevated portion  60  includes a series of grooves  70  and bars  80  between the series of grooves  70 . Each of the first and second clutch plates  40  and  50  also include a central portion  90  which may have a series of holes  100  positioned therein.  
         [0020]    The first and second clutch plates  40  and  50  may be positioned such that the elevated portions  60  face each other. The bars  80  in the elevated portion  60  of one clutch plate fit into the series of grooves  70  of the elevated portion  60  of the other clutch w plate. When the elevated portions  60  fit together, this results in the first and second clutch plates  40  and  50  being in an interlocked, secure position relative to each other, such that neither of the first or second clutch plates  40  and  50  can move laterally until the bars  80  are disengaged from the series of grooves  70 .  
         [0021]    The first and second clutch plates  40  and  50  may include any number of grooves  70  and bars  80  in their elevated portions  60 . Additionally, the grooves  70  and bars  80  may be flat with respect to the other components of the first and second clutch plates  40  and  50 , or may be depressed within the first and second clutch plates  40  and  50 . Other embodiments for interlocking the first and second clutch plates are also contemplated in the present invention. For example, a gear system may be used to interlock the first and second clutch plates to prevent their movement relative to each other. It is noted that any means of providing interlocking mechanical components can be used with the present invention to achieve a locking system that prevents one or more components from moving.  
         [0022]    The pivot joint apparatus  10  also includes a pivot piece  110  positioned in one of the joint plates in the first pair of joint plates  20 . The pivot joint apparatus  10  also includes a release mechanism. In one embodiment, the release mechanism has a series of pins  120  housed in a head portion  130 . The series of pins  120  penetrate the first pair of joint plates  20 , the pivot piece  110 , and the first clutch plate  40 . The series of pins  120  also contact with the second clutch plate  50  and, when activated by exerting pressure on the head portion  130 , cause the second clutch plate  50  to move away from the first clutch plate  40  as described in greater detail below. The head portion  130  may also include a post  140  and a closure cap  150 . Each of the first and second clutch plates  40  and  50  include a post hole  190  through which the post  140  passes.  
         [0023]    The head portion  130  may also include a housing  210  within which the series of pins  120  and the post  140  are positioned. In one embodiment, the series of pins  120  are activated by pressing or pushing the head portion  130  to force the series of pins  120  to extend down to exert force on the second clutch plate  50 . In another embodiment, the closure cap  150  acts as a button which can be pushed to activate the series of pins  120  and force them to extend down to exert force on the second clutch plate  50 . In yet another embodiment, activation mechanisms, such as push buttons, may be positioned on the pairs of joint plates  20  or  30  to activate and extend the series of pins  120 .  
         [0024]    Other embodiments for release mechanisms are also contemplated for use in the present invention. In one embodiment, any number of pins may be used to release the first and second clutch plates. In another embodiment, the joint plates  20  and  30  may include levers or switches which, when pressed or activated, cause the first and second clutch plates to separate. It is noted that any method of causing the release or separation of the first and second clutch plates is contemplated for use with the present invention.  
         [0025]    Each joint plate in the first pair of joint plates  20  may be coupled together by the post  140  and the series of pins  120 . Each joint plate in the second pair of joint plates  30  may also be coupled together by the post  140 .  
         [0026]    The pivot piece  110  provides a large, non-rotating diameter about which the pivot joint apparatus  10  can be adjusted. In one embodiment, the pivot piece  110  is a washer positioned adjacent to the central portion  90  of the first clutch plate  40 . When the first and second clutch plates  40  and  50  are disengaged, the pivot joint apparatus  10  is adjustable by rotating joint plates in the first and second joint plates  20  and  30  about the pivot piece  110 .  
         [0027]    The pivot joint apparatus  10  may also include a spring mechanism  160 . The second clutch plate  50  includes a first extension  170 . One of the joint plates in the second pair of joint plates  30  includes a second extension  180  which is capable of insertion into the first extension  170 . The spring mechanism  160  may be a coil wound around the first extension  170  and the second extension  180 . The post  140  extends all the way through from the head portion  130  to the second pair of joint plates  30 , as shown in FIG. 1.  
         [0028]    [0028]FIG. 2 is a perspective view of a portion of the system of plates of the pivot joint apparatus  10 . The first pair of joint plates  20  and the first clutch plate  40  are shown, with a portion of the first clutch plate  40  removed to show the pivot piece  110 . The series of holes  100  through which the series of pins  120  pass extend through the first pair of joint plates  20 , the pivot piece  110 , and the first clutch plate  40 .  
         [0029]    [0029]FIG. 3 is a perspective view of the pivot joint apparatus  10  according to the present invention, showing the various components in separated fashion. The pivot joint apparatus  10  may be used with any device or article of manufacture requiring an adjustable pivot joint. FIG. 3 shows members  200  which are securable to the pivot joint apparatus  10 . The position of the members  200  can be adjusted by rotating at least one joint plate in each of the first and second pairs of joint plates  20  and  30  together about the pivot piece when the first and second clutch plates  40  and  50  are separated. One example of the use of a pivot joint apparatus  10  according to the present invention is in wheelchairs or strollers. Often, occupants of wheelchair or strollers must adjust the positioning of leg or arm rests or other components. This can be cumbersome for some occupants. Using the present invention, an occupant activates the release mechanism, adjusts the pivot joint apparatus and the component connected thereto to a desired position, and then deactivates the release mechanism. Additionally, the clutch plate locking feature adds strength and durability to the pivot joint component of the wheelchair or stroller. Accordingly, the members  200  are portions of a mechanical component to which the pivot joint apparatus is connected. The members  200  are provided to show a particular use for the pivot joint apparatus of the present invention. It is noted that although various aspects of the present invention are described in the context of wheelchair and strollers, those skilled in the art will appreciate that the pivot joint apparatus of the present invention is likewise suitable for use in various other mechanical environments. Accordingly, any reference to wheelchairs and strollers is intended only to illustrate the inventive aspects of the present invention, with the understanding that such inventive aspects have a wide range of applications.  
         [0030]    [0030]FIG. 4 is a side view of the pivot joint apparatus  10 . The pivot joint apparatus  10  of FIG. 4 is in an unlocked position and ready for adjustment. To unlock, or disengage, the first and second clutch plates  40  and  50 , the release mechanism is activated to force the series of pins  120  to extend and push the second clutch plate  50  away from the first clutch plate  40 . This results in the bars  80  and the series of grooves  70  being disengaged from each other, allowing lateral movement of the first clutch plate  40  relative to the second clutch plate  50 . Once the first and second clutch plates  40  and  50  have been disengaged, at least one of the joint plates in the first pair of joint plates  20  can be rotated, in conjunction with at least one joint plate from the second pair of joint plates  30 , about the pivot piece  110 .  
         [0031]    When the series of pins  120  pushes the second clutch plate  50  away from the first clutch plate  40 , the second clutch plate  50  pushes against the spring mechanism  160 . When not pushed down by the second clutch plate  50  and the series of pins  120 , the spring mechanism  160  also serves to bias the second clutch plate  50  against the first clutch plate  40  to provide further stability for the system of plates when the bars  80  and the series of grooves  70  of the first and second clutch plates  40  and  50  are engaged.  
         [0032]    [0032]FIG. 5 is another side view of the pivot joint apparatus  10 . The pivot joint apparatus  10  of FIG. 5 is in a locked position such that the plates making up the system of plates do not move. In FIG. 5, the first and second clutch plates  40  and  50  are engaged in a locked position, preventing the system of plates, and therefore the pivot joint apparatus itself, from moving. Additionally, the spring mechanism  160  biases the second clutch plate  50  against the first clutch plate  40 .  
         [0033]    The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Systems and techniques are disclosed for providing an adjustable pivot joint apparatus. The apparatus includes a plate system having interlocking clutch plates which, when separated, allow the apparatus to pivot about an axis. The interlocking clutch plates prevent the apparatus from pivoting about the axis when in a locked position. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.