Abstract:
The present invention is an ingenuously designed self locking hinge that is simple to manufacture and can come in a variety of shapes given the application requirements. It has few parts making it cost effect and simple to use. The hinge can easily be opened and closed with one hand while at the same time creating a strong hinge connection. The invention can be used in a number of applications, including use with poles for many common applications such as walking sticks, canes, ski poles and wading staffs used by fly fishermen who need poles to navigate through a stream to avoid holes or rocks in the stream bed. The invention can also be used in conjunction with devices that require a collapsible frame.

Description:
BACKGROUND 
   a) Field of the Invention 
   This invention relates to the field of folding hinges designed for use in conjunction with devices that use poles or similar means and where it is desirable to collapse the same. More specifically, this device relates to devices that are used in conjunction with ski poles, canes, walking sticks, or wading staffs used by fishermen. This invention consists of a self-locking hinge that can be operated with one hand making use of the poles and related devices convenient. 
   b) Description of the Related Art 
   The present invention is directed towards folding or collapsible hinges that are designed for use in conjunction with poles or similar devices. Presently, there are different folding hinge designs that can be used in conjunction with poles or other devices to create collapsible frames. However, none of the prior art incorporates all of the novel aspects of the present invention of a simple, inexpensive, easy to manufacture, strong self locking hinge that most importantly can be operated with one hand. 
   A common collapsible hinge assembly in the prior art uses spring loaded poles that facilitate both the opening of the hinge assembly and the maintaining of the hinge assembly in a closed position. Some devices do not use an actual hinge at the connection point but rely on the spring loaded, or bungee cord loaded, poles and a sleeve type arrangement where one pole possess a sleeve designed to slide over a second pole. This arrangement is common with poles used for wading staffs, to support pop up camping tents and other similar devices. The main draw back is that two hands are required to assemble the two sections of the pole due to the combination of the internal spring mechanism and the overlapping sleeve arrangement. Other devices have an internal spring loaded means, such as U.S. Pat. No. 4,736,490, but have many internal parts that make is complicated and costly to manufacture. The present invention has only three basic parts and can be simply manufactured and placed inside a pole without any internal components. 
   Some devices use sleeves to facilitate the locking means such as in U.S. Pat. No. 5,139,283. This device is similar to the present invention, as it is used in conjunction with ski poles. The draw back with this device is that one needs to use two hands to operate the device, as one would have to hold the poles in place while they slide the sleeve over the hinge portion. Other devices do not use springs or sleeves, such as U.S. Pat. No. 3,833,964, but use the pole material to create the spring action. This device falls from the shortcoming of not yielding a true end-to-end 180-degree connection desirable for walking sticks and canes. Furthermore, this hinge device could be disengaged if one where to apply force to underside of the hinge, a concept not desirable to wading staffs, walking sticks and canes. 
   Still other devices utilize a latch mechanism as the present invention. One such example is U.S. Pat. No. 96,777, a device specifically designed for use with an umbrella. This device does not create a straight 180-degree orientation and does not easily collapse down for easy storage. Further, it does not have an offset hinge connection as the present invention preventing the device from being collapsed to a compact sized for easy transport and storage. 
   Some devices possess an offset hinge pivot connection. An example can be seen in U.S. Pat. No. 5,685,660 and its cited prior art references contained within the patent. All of these references suffer from the common problems of not being able to be engaged or disengaged with one hand. The cited reference itself does have a push button to release the mechanism but in doing so one&#39;s own finger will be holding the press plate of the opposite hinge portion preventing the same from disengaging from the main hinge portion, thereby preventing the device from being a one hand operation. 
   In sum, the present invention overcomes all the shortcomings of the prior art and discloses a simple self locking hinge. The design is simple to manufacture, can come in a variety of shapes given the application requirements and has few parts making it cost effect. The hinge can be simply opened and closed with one hand while creating a strong axial connection between two poles that is sufficient to be used as a wading staff, walking stick, cane or other device. 
   SUMMARY OF THE INVENTION 
   The invention consists of an ingenuously designed self locking hinge that can be used in a number of applications. The hinge can be used in conjunction with poles for many common applications such as walking sticks, ski poles and poles used by fly fishermen who need wading staffs to navigate through a stream to avoid holes or rocks in the stream bed that are not readily apparent to the naked eye. The invention can also be used in conjunction with devices that require a collapsible frame such as baby carriages or golf bag carts to name a few. 
   One key advantage of the invention is that it can be opened and closed with one hand and with one fluid motion. In the case of a wading staff a person simply holds the upper half of the wading staff containing the handle and releases the bottom half of the wading staff. The self locking hinge automatically engages once the bottom half of the wading staff is in place, that is, lined up end to end with the top half of the wading staff (See  FIG. 4  and  FIG. 5 ). This single hand operation is desirable and convenient in many applications, and more specifically, with a fly fisherman who is generally holding a fishing rod in one hand and thus only has one hand free to manage a wading staff. 
   Another advantage of the invention is that it allows for a wading staff, or other pole device, to be broken down to a compact size for easy transportation and storage. This is desirable in almost all applications, especially wading staffs and canes. If needed several hinges may be placed in the pole thereby allowing the pole to be folded a number of times, further reducing the size of the pole for transport and storage. 
   The invention consists of essentially three pieces; two hinge portions that are pivotally joined and a self locking latch that locks the two hinge portions together. The two hinge portions are designed to be disposed end to end and are pivotally engaged with each other around a pivot pin. The hinge portions are geometrically designed so that they do not protrude beyond the pole diameter. The only exceptions are the lobe portions of the hinge that create an offset pivot point. The offset pivot point allows the poles attached to the hinge to touch and to be parallel when the entire pole is in its closed position. The third portion of the invention is the self locking latch which is spring actuated. The self locking latch is permanently attached to one hinge portion. The self locking latch locks the invention by engaging a recess or notch in the opposing hinge portion. When engaged the hinge creates a strong connection that is sufficient for its application purpose. The invention is simply unlocked by pressing down on the self locking latch. 
   Accordingly, one object of this invention is to provide a self locking hinge that can be easily engaged and disengaged with one hand. 
   Another object of this invention is to provide a self locking hinge that is simple and inexpensive to manufacture. 
   A third object of this invention is to provide a self locking hinge that can be incorporated with poles, or other devices, so that one may possess a poled, or other, device that is strong in nature while being capable of being broken down to a compact size for easy transport and storage. 
   Other objects and advantages of this invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where, 
       FIG. 1  is a plan view of the invention, 
       FIG. 2  is a cut away plan view of the invention in its engaged position and showing the self locking latch engaged, 
       FIG. 3  is a perspective view of the invention, 
       FIG. 4  is an elevation view of the invention in its closed position and used in conjunction with poles for a wading staff, 
       FIG. 5  is an elevation view of the invention in its engaged position and used in conjunction with poles for a wading staff, 
       FIG. 6  is cross sectional view of the connection between the self locking latch and the first hinge portion. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the Figures and more specifically  FIG. 1  and  FIG. 3 , the invention  10  consists of essentially three parts, a first hinge portion  12 , a second hinge portion  14  and a self locking latch  16 . Each hinge portion has a main body portion and a connecting portion containing lobes designed to connect the two hinge portions. The first hinge portion  12  has a main body portion  18  and a connecting portion  20  with two lobes  26  and  54 . The second hinge portion  14  has a main body portion  22  and a connecting portion  24  with a single lobe  28 . The main body portions of the hinge portions are design to allow the hinge portions to be engaged with poles or other devices. In  FIG. 1 , the main body portion  18  of first hinge portion  12  is disposed in pole  30  while the main body portion  22  of second hinge portion  14  is disposed in pole  32 . The invention  10  can be made in a variety of geometric shapes so that it can be connected with variety of different shaped poles or devices requiring the invention  10 . The preferred embodiment of the invention  10  is to have the main body portions of the hinges cylindrical in shape so that they may be accepted into a hollow cylindrical pole device. 
   The lobes  28 ,  26  and  54  extend from the bottom of their respective connecting portions and are designed to engage each other. The single lobe  28  is designed to be disposed between the two lobes  26  and  54 . Each lobe has a hole and when the invention  10  is assembled all three holes of the lobes are axially aligned with each other. A single pin  56  is disposed within the three holes of the lobes thereby providing a means to connect the lobes and thus connect the hinge portions. The pin and lobe connection provides a means to allow the hinge portions to be pivotally joined and allow for the hinge portions to engage and disengage. The lobes protrude from the base of their respective connecting portions and therefore are offset from the main center axis of the hinge portions. In the preferred embodiment the lobes are offset a sufficient distance so as to allow the hinge portions to pivot in a full 180-degree orientation from being parallel to each other to being axially aligned end to end.  FIG. 4  and  FIG. 5  illustrates the full movement of the invention  10  from its disengaged, or closed, position to its engaged, or open, position, with only the handle  48  of the wading staff  52  preventing the hinge portions from being in perfect parallel orientation. The handle  48  may alternatively be designed to allow for perfect parallel alignment of the poles. 
   The self locking latch  16  is the part of the invention  10  that locks the two hinge portions together end to end so that a strong connection is made. At the bottom of one end of the self locking latch  16  is a connecting lobe  34  designed to engage a recess  36  in the main portion  22  of the second hinge portion  14 . The preferred embodiment is to have the connecting lobe  34  in a 90-degree orientation with the main portion of the self locking latch  16 . At the opposite end of the self locking latch  16  is a press tab  38  that is disposed on the top of the self locking latch  16 . A recess  40  is disposed on the bottom of the self locking latch  16  and directly opposite the press tab  38 . The recess  40  is designed to accept a spring  42  which itself is disposed within the main body portion  18  of the first hinge portion  12  (see  FIG. 2 ). The spring  42  is disposed between the main body portion  18  and the recess  40  and provides a means for keeping the self locking latch  16  engaged in the recess  36 , and thus the invention  10  engaged. The spring  42  also provides a means to release the self locking latch  16  from the recess  36 . 
   On each side of the self locking latch  16  are two pivot lobes  44  and  64  designed to engage a single lobe  66  protruding up from the top part of the connecting portion  20  (See  FIG. 6 ). A hole is disposed in all three lobes in such a manner that when the three holes are axially aligned the self locking latch  16  is in place in relation to the first hinge portion  12 . A pin  46  is placed in holes of the lobes  44 ,  64  and  66  so that the self locking latch  16  can be connected to the first hinge portion  12  and which provides a means for the self locking latch  16  to move pivotally on top of the first hinge portion  12 . This connection in conjunction with the spring  42  allows the self locking latch  16  to be engaged and be disengaged from recess  36 . 
   The invention  10  can be easily assembled, by placing the main portions of the hinges into the devices to be connected. In  FIG. 4  and  FIG. 5  the invention is used in conjunction with a collapsible wading staff  52 . The invention  10  is disposed within the two poles  30  and  32  of the wading staff  52 . A handle  48  is at the top of the wading staff  52  and provides a means to lock the two poles together when folded. A rubber shoe  50  is at the base of the wading staff  52 . A metal pivot  62 , preferably steel, can be inserted into the rubber shoe  50  to prevent excessive wear on the shoe.  FIG. 4  displays the invention  10  in its closed position for easy storage and/or transportation.  FIG. 5  displays the invention  10  in its open or engaged position. 
   In the example of the wading staff  52 , engaging and disengaging the invention  10  is easy and can be accomplished with one hand. To engage the invention  10  and thus open up the wading staff  52 , one need only hold on to pole  30 , preferably near the handle  48 , separate the pole  32  from the pole  30  with one&#39;s fingers and then let gravity or other force allow the pole  32  to drop down to its closed position. In its closed position the two poles will be axially aligned with each other in an end-to-end orientation. To disengage the invention  10  one need only to push down on the press tab  38  thereby depressing the spring  42  causing the self locking latch  16  to pivot on pin  46  resulting in the connecting lobe  34  exiting the recess  36  sufficiently so that the invention  10  is disengaged. The two poles  30  and  32  can be folded back to the closed position. To accomplish this with one hand one need only raise the wading staff  52  off the ground a sufficient distance such that gravity will allow the pole  32  to release from its axial orientation with pole  30  and return to it closed position, parallel or nearly parallel, to pole  32 . 
   In the preferred embodiment the spring  42  is designed to be sufficiently depressed to allow the connecting lobe  34  to exit the recess  36  a sufficient distance so that the connecting portion  24  does not hinder the connecting lobe&#39;s  34  ability to release from the second hinge portion  14 . For ease of operation, the bottom surface of the connecting lobe  34  is rounded. Also, the leading edge of the connecting portion  24  is rounded off a sufficient amount so as to aid in allowing the connecting lobe  34  to “roll” over the connecting portion  24  to the recess  36 . Although this arrangement is not necessary as in the preferred embodiment the spring  42  can be pressed sufficiently enough to allow the connecting lobe  34  to pass over the connecting portion  24  without interference, the invention  10  is designed in this manner just in case a user for some reason does not fully depress the spring  42  sufficiently and thus needs the rounded surfaces of the connecting lobe  34  and connecting portion  24  to aid in the engagement of the invention  10 . Once the connecting lobe  34  is disposed in recess  36  and the hinge portions are axially aligned end-to-end and the invention  10  is engaged. The spring  42  maintains a constant vertical pressure on the self-locking latch  16  and therefore keeps the connecting lobe  34  in the recess  36 . All the tolerances on all the parts of the invention  10  are sufficiently tight and a secure connection is made locking the hinge portions in place. The invention  10  is designed so that it can be engaged and disengaged with the minimal of force placed on the press tab  38 . 
   The self locking latch  16  has two flanges  58  and  60  that protrude out of the side of the self-locking latch  16 . The flanges  58  and  60  are designed to provide a stop for the self-locking latch  16 . When the self-locking hinge  16  is engaged, the flanges  58  and  60  rest on the top part of the connecting portion  20 . The combination of the flanges  58  and  60  resting, or stopping, on the top part of the connecting portion  20  and the pressure created by the spring  42  maintain the self-locking latch  16  in a secure position and prevents the self-locking latch  16  from moving while the engaged invention  10  is in use. 
   The invention can be made from any strong material, for example metal or plastic, with the preferred embodiment being machined aluminum. The parts are simple in design and can be made using standard machining techniques.