Abstract:
A self-latching hinge mechanism ( 14 ) and apparatus ( 10 ) for applications where access to a pole mounted device is required. The hinge comprises a top section ( 28 ) with a cantilevered tail piece ( 38 ) which extends beyond a pivot ( 36 ) connected at the top ( 40 ) of a lower section ( 30 ). A latch consists of an encircling slide ( 32 ) which binds the tail piece ( 38 ) to the lower part of the pivot section ( 30 ) when in the lowered, locked position and allows the top section piece ( 28 ) to rotate relative to the lower section ( 30 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit under 35 U.S.C. § 119(e) of U.S. provisional application Ser. No. 60/498,057 filed Aug. 27, 2003. The aforementioned provisional application is incorporated by reference in its entirety. 

   FIELD OF THE INVENTION 
   The present invention relates generally to a hinge and more particularly, a self-latching pipe hinge mechanism. The present invention will be described herein primarily by way of reference to devices which may be used to support hanging bird feeders, hanging plants, or the like, where the load must be supported at some distance from the ground for security or visibility while retaining accessibility for replenishment or maintenance and will be described herein primarily in reference thereto. However, it will be recognized that the present invention may be employed in connection with all manner of support structures for hanging or suspending objects above a surface. Other uses include but are not limited to flag poles, volleyball, basketball, or other net supports or poles, utility or decorative light poles, awnings, umbrellas, sun shades, outriggers, and the like. 
   BACKGROUND OF THE INVENTION 
   There are numerous ways to mount a bird feeder. There seem to be two prevalent pole-based solutions. The feeder-on-top where the feeding device is mounted at the top of a fixed pole and the hanging feeder where the feeder is suspended from a bracket or the top of an offset section that loops vertically around the feeder to maintain the center of gravity of the feeder over the base of the pole. The lower end of both of these is either embedded in the ground or fastened to a building or some sort of base. These and most of the other existing pole based solutions and accessories seem to adequately address the issues of security and visibility. Security and visibility, up to some degree, improve as a function of height. Accessibility varies inversely with height. Stepladders are necessary for refilling higher pole mounted bird feeders with the exception of the types that separate in the middle so that the top section can be lifted out of the bottom section allowing the feeder to be lowered for replenishment. This arrangement severely limits the size and weight of the feeder that can deployed in many cases and therefore shortens the time between necessary refills. Older or more frail individuals might have difficulty lifting or not be able to lift some of the larger, longer lasting feeders into place when full and therefore might have to refill more often or forego refilling entirely in cold or inclement weather. 
   Accordingly, the present invention contemplates a new and improved pipe hinge, and bird feeder apparatus and method incorporating the same, which overcome the above-referenced problems and others. 
   SUMMARY OF THE INVENTION 
   The tilting/tipping bird feeder pole incorporating the pipe-hinge slide lock technology provides the possibility for many individuals who might otherwise be severely limited, to potentially utilize larger heavier feeders that accommodate more birds and hold more food, providing longer periods between refills. The tilt-pole/pipe-hinge in accordance with the present invention is preferably a heavy duty assembly fabricated from steel pipe instead of lighter tubing as are most other types of bird feeder poles. In a preferred aspect, the pole is designed to be shipped in three sections and easily assembled in the field with readily available tools. The three sections consist of a top section bent to form a vertical loop around the bird feeder so that the feeder hangs directly above the base of the pole for balance, a center section which is the pipe-hinge and slide lock, and a bottom or base section, preferably made from a larger diameter pipe for additional strength. In an especially preferred embodiment, the base section is terminated at the bottom with a pointed plug designed to make driving the base pipe into the ground easier and more importantly to force the displaced earth to compact around the base section instead of filling the pipe thus making the surrounding earth firmer and the base section more stable in the ground. 
   The operation of the pole is intended to be easy even in the case where the operator might be small or frail or the bird feeder might be large and heavy. Such an operator might be able to lift the slide latch with one hand and lower the pole and empty feeder with the other to the point where the slide latch is captive above the pivot point and then lower the pole and feeder to the ground with both hands. Such an operator might then, after filling the feeder, be able to raise the feeder to the upright position with both hands and the full pushing strength of the body without the need to manually operate the gravity activated slide latch. The tailpiece of the upper hinge section keeps the operator from possibly encountering a situation wherein because of the mass of the upper pole section and the full feeder, the pole top might tend to pass the vertical and continue back to the down position on the other side before the slide latch can drop into the down or locked position. Still further benefits and advantages of the present invention will become apparent to those skilled in the art upon a reading and understanding of the preferred embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings, wherein like reference numerals refer to like or analogous components throughout the several views, are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention. 
       FIG. 1  is a side view of the bird feeder application of the pipe-hinge slide lock in the upright or locked position. 
       FIG. 2  is a side view of the bird feeder application of the pipe-hinge slide lock in the unlocked rotated or down position. 
       FIG. 3  is a detail view of the pipe-hinge slide lock assembly. 
       FIGS. 4–6  are fragmentary views of a device according to the present invention illustrating optional means for assisting a user in raising the pole to the upright position. 
       FIG. 7  is a fragmentary cross-sectional view of a preferred pivot joint employing a solid plug and pivot bushing. 
       FIG. 8  is a fragmentary cross-sectional view of an embodiment employing pointed plug to facilitate embedding the lower end of the pole device in the ground. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the  FIGS. 1–3 , an exemplary embodiment of a bird feeder pole/plant hanger pole apparatus  10  embodying the pipe-hinge slide lock of the present invention consists of three sections, namely, a top section  12 , a middle section  14 , and a base section  16 . The top section  12 , in the depicted embodiment, may be fabricated from steel pipe and is fitted at the end of the upper extremity with a hook  18  for supporting a hanging bird feeder  20  or other object to be suspended, such as planter or the like. The hook  18  is preferably fabricated from steel although other materials are contemplated. 
   The top section  12  is bent in such a fashion as to provide a clearance or opening  22  for receiving the bird feeder  20  (for the sake of brevity, the item to be suspended will be described herein primarily by way of reference to the preferred embodiment wherein the hanging item is a bird feeder; however it will be recognized that this discussion is equally applicable to any other item to be suspended). This clearance or opening  22  preferably suspends the bird feeder  20  in a position which is generally centered over the lower and middle sections  14  and  16  to afford balance and support. 
   In the depicted embodiment, the device  10 , distal end  24  of the bottom pole section  16  may be driven into the ground  26  or other surface, although other means for securing or anchoring the base section  16  to the surface  26  are contemplated. The bottom portion  16  is preferably fabricated from a larger diameter steel pipe for additional strength and to displace a larger volume of earth when driven into the ground  26 . In this preferred embodiment, additional stability may be provided from compaction of the earth  26  surrounding the embedded portion of the base section  16 . 
   The base section  16  is open at the top to receive the bottom section of the pipe-hinge slide lock assembly and, in the depicted embodiment, is terminated at the distal end  24  with a pointed, e.g., conical, plug  26 . As best seen in  FIG. 8 , the pointed plug  26  is designed to make driving the base pipe into the ground easier and to force the displaced earth to compact around the base section, instead of filling the distal pipe end  24  with earth, thus making the surrounding earth firmer and the base section more stable in the ground  26 . It will be recognized that other methods of embedding or securing the base section to the ground, floor, or other surface are also contemplated. 
   The middle section, or pipe-hinge slide lock assembly,  14  is best seen in  FIG. 3 , and consists of three main pieces, namely, a hinge top or cantilever section  28 , a hinge bottom portion  30 , and a sliding latch or sleeve  32 . The hinge top section may be fabricated, for example, from steel pipe and, in the depicted embodiment, is adapted to receive the top section  12  telescopically therewithin. The hinge top section  28  may be of the same diameter as pole bottom or base section  16 . The hinge top section  28  and the top section  12  may be secured in fixed telescoping relation via a bolt or retention pin  34 , e.g., passing through aligned holes formed in the respective members  12  and  28 . 
   As described above, the middle section top portion  28  is open at the top to receive the bottom end of the smaller diameter pole top section  12 . Approximately centrally located along the length of the hinge top section  28  is a hinge or pivot pin  36 , which is preferably welded or otherwise permanently secured in place. The pin  36  engages an opening in the top portion of the hinge bottom section  30 . An optional bearing may be provided as described in detail below. Thus, in operation, the top portion  28  forms the movable part of a rotating pivot point about the hinge/pin  36 . 
   The hinge top section  28  further includes a cantilevered tail section  38  extends past the pivot pin or hinge point  36 . The cantilevered tail section  38  is preferably integrally formed with the hinge top section  28  and, in the depicted embodiment, is formed by removing approximately one-half of the circumference of the pipe material forming the hinge top section  28  that extends beyond the pivot point  36 . Thus, in the depicted embodiment, the tail section  38  is approximately semicircular in cross-sectional shape. The hinge bottom section  30  is preferably slightly smaller in diameter than the hinge top section  28  so as to enable the hinge bottom section to fit within the tail section  38  when the hinge top portion  28  is moved into the upright position (see  FIG. 1 ). For example, the outer diameter of the bottom hinge section  30  may be roughly equal to the inner diameter of the hinge top section  28 . The hinge bottom portion  30  and the top pole section  12  may be of the same diameter. Likewise, the hinge top section  28  and the bottom pole section  16  may be of the same diameter. A portion of the hinge bottom portion  30  thus fits within and against the inward facing portion of the tail piece  38  when the hinge top and bottom portion members are coaxially aligned, i.e., when the hinge is in its upright position. 
   The pipe hinge portion  14  is held in an upright position by the annular slide latch piece  32  which is adapted to circumscribe the top pipe hinge section  28  when the pole is in the tilted or down position and is slidably moved in the axial direction to secure the tail section  38  against the hinge bottom section when the pole  10  is in the upright operational position. In this manner, the slide lock piece  32  keeps the hinge top section  28 , and thus the pole top section  12 , coaxially aligned with the hinge bottom section  30  and the pole bottom or base section  16 . The hinge bottom section  30  may be fabricated from steel pipe and may be the same diameter as the pole top section  12  to allow it to fit the inside diameter of the hinge top section  28  and to be received into the upper end of the pole bottom or base section  16 . In the depicted embodiment, the hinge bottom section  30  and the base section  16  are secured in fixed telescoping relation via a bolt or retention pin  34 , e.g., passing through aligned holes formed in the respective members  16  and  30 . In the depicted embodiment, the upper end  40  of the hinge bottom section  30  is rounded or angled to provide clearance for the inner circumference of the hinge top section  28  as the pivot joint rotates. 
   The hinge or pivot pin  36  may be provided via a number of means. For example, in a embodiment illustrated in  FIG. 7 , the top end  40  of the hinge bottom section  30  may be fitted with a plug  50 , such as a steel plug which is drilled to accept the pivot pin  36  from the hinge top section  28  through a transversely extending opening  52 . Preferably the opening  52  is sized to accept a bearing  54 , e.g., formed of bronze or other metal or metal alloy. The bearing  54  includes a through bore  56  receiving the pin  36  therethrough, e.g., for wear improvement and/or to keep rust from immobilizing the pivot point. The plug in the top end  40  of the hinge bottom section  30  is machined to a rounded and/or angled profile  58  so as to provide clearance for the inner circumference  60  of the hinge top section  28  as the pivot joint rotates. The bottom of the hinge bottom section  30  is received into the top of the pole bottom or base section  12  as described above. 
   The sliding latch member  32  consists of a peripheral sleeve, such as a short section of pipe, such as steel pipe. The sliding latch  32  has an inside diameter which is larger than the outside diameter of the hinge top section  28  (and the pole bottom or base section  16  when like sized pipe is used in accordance with the depicted embodiment) such that it can slide freely along the length of the pipe-hinge  14  in order to lock or unlock the assembly. The slide piece movement is restricted by a protrusion or stop at each end of the pipe hinge slide lock assembly  14 , which may advantageously be the retaining pins, or more preferably bolts  34  or the like that are used to secure the top pole section  12  to the hinge top section  28  and the bottom pole section  16  to the bottom hinge section  30 . In the depicted preferred embodiment, the bolts or pins  34  serve to fasten the ends of the pipe-hinge slide lock assembly  14  to the respective pole top section  12  and pole bottom section  16 , although separate dedicated stop members are also contemplated. 
   In operation, when the slide  32  is lifted and the two sections  28  and  30  move away from coaxial alignment, it is no longer possible for the slide  32  to return to the locked position until the two sections  28  and  30  are coaxially re-aligned, e.g., by lifting the top pole section  12  to the upright position. This feature allows the possibility that an operator having once lifted the latch to lower a pole connected to the pipe-hinge mechanism might then be afforded the use of both hands to raise the pole again. In the preferred, vertical application depicted, the slide  32  automatically moves to the locked position by the force of gravity when the two hinge sections achieve coaxial alignment. This embodiment may be adapted for use in a non-vertical application by employing a spring attached to the sleeve  32  which biases the sleeve toward the locked position. To unlock the hinge, the sleeve  32  is moved against the bias of the spring and the top hinge section is moved out of axial alignment with the bottom hinge section  30 . When the top hinge section  28  is moved back into axial alignment with the bottom hinge section  30 , the spring urges the sleeve back to the locked position. In the preferred embodiment, the pole sections  12  and  16  and the hinge sections  28  and  30  are formed from round pipe, preferably steel or other metal or metal alloy. However, the device could be fabricated from a number of different materials exhibiting a diversity of cross-sectional shapes, including rectangular, polygonal, or other geometric cross-sectional shapes. 
   With reference now to  FIG. 4 , an alternative embodiment is shown having an optional counterweight or counterbalance  42 , provided on the tail section  38  to further assist a user in moving the upper section between the lowered and upright positions. In the depicted embodiment, the counterweight  42  is shown somewhat schematically and may take any desired geometric configuration. Also, in the depicted embodiment, the counterweight  42  is shown attached directly to the tailpiece  38 . Alternatively, however, a boom or extension (not shown) may be provided to increase the distance between the counterweight  42  and the pivot point  36 . Likewise, the counterweight  42  and/or the distance between the counterweight  42  and the pivot point  36  may be made variable. 
   Alternatively, as shown in  FIG. 5 , or in addition to the counterweight  42  as shown in  FIG. 6 , a counterweight or other energy storage device  44  could be provided within the base pole section  16  and coupled to a movable portion of the device, preferably the tail piece  38 , via a cable or other mechanical linkage  46 . In the depicted embodiment, the cable  46  cable is illustrated passing through an opening  48  in the lower hinge section  30 . In operation, as the top pole portion  12  is pivoted and lowered to a tilted position, potential energy is stored by the energy storage device  44  to assist the user when returning the pole to the upright position. 
   For example, in the case of a counterweight  44 , energy is stored as the weight is lifted to a higher position. Alternatively, the energy storage device  44  may be a spring, such as a helical spring, preferably contained within the tubular portion  16  and coupled to a movable portion of the unit  10 . For example, by securing the cable/coupler  46  to a first end of the spring and securing the opposite end within the pole base  16 , energy may be stored as increased spring tension when the top section  12  is pivoted to a lowered position. This increased spring tension serves to bias the pole section  12  back toward the upright position, thereby storing energy to assist the user in returning the pole to its upright position. Other devices are contemplated for use as the optional energy storage device  44  for assisting the user in returning the upper pole section  12  to its upright position, such as an air piston and cylinder assembly, or the like. 
   Also, combinations of such energy storage devices may be employed. For example, in  FIG. 6 , an external counterweight  42  as described above is employed in conjunction with an internally mounted energy storage device  44  as described above. 
   The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. For example, the middle hinge section  14  need not be separable from the top and bottom pole sections  12  and  16 , respectively. Thus, one or both of the upper hinge section  28  and lower hinge section  30  may be integrally formed with the respective top and base pole section  12  and  16 . In one embodiment, the pole top section  12  is integrally formed with hinge cantilever section  28 , and the pole base section  16  is separately attachable to lower hinge pivot section  30 . In another alternative embodiment, the pole top section  12  is separately attachable to the hinge cantilever section  28 , and the pole base section  16  is integrally formed with the lower pipe hinge pivot section  30 . In yet another alternative embodiment, the pole top section  12  is integrally formed with the hinge cantilever section  28 , and the pole base section  16  is integrally formed with the lower hinge section  30 . Also, it will be recognized that the cantilever and pivot sections  28  and  30  may be reversed from the depicted preferred embodiment such that the cantilever hinge section  28  is retained within or integrally formed with the base pole portion  16  and the lower hinge pivot section  30  engages or is integrally formed with the pole top section  12 . Also, the depicted preferred embodiment illustrates the various sections fastened in affixed telescopic relation using a bolt or pin passing through aligned holes. However, other fastener types may also be employed, such as complimentary threaded section ends, mating flanges, clamping rings, and the like. It is intended that the invention be construed as including these and other modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.