Not Applicable.
Not Applicable.
1. Field of Invention
The invention relates to a hinge for a pet door. More specifically, this invention relates to a flexible hinge adapted to resist damage or breakage resulting from undesirable forces applied to the hinge during the normal course of operation.
2. Description of the Related Art
Conventional pet doors have a movable flap residing within a frame. Soft flap pet doors take advantage of the flexibility of the flap to allow ingress and egress, such as that shown and described by Davlantes in U.S. Pat. No. 4,408,416. Hard flap pet doors must use a hinge mechanism to allow for movement of the flap. There are many basic hinge mechanisms commonly employed. One example of a common hinge mechanism is the molding of the shaft and the hinge tube as part of the flap and the frame, such as that shown and described by Green, in U.S. Pat. No. 4,776,133. Another example, is the use of a cam resting on a shelf, such as that shown and described in by Marsh, et al., in U.S. Pat. No. 6,385,909, or a cam resisted by a biasing member such as that shown and described by Pennock in U.S. Pat. No. 3,978,616. In yet another example, the flap and the frame may be connected by conventional hinges, such as that shown and described by Peterson in U.S. Pat. No. 5,581,940.
Each of the hard flap pet doors share the common concern of the hinge mechanism being subjected to potentially damaging forces, for example, the over-rotation of the flap. If the flap is pushed beyond the rotational limits afforded by the hinge mechanism, some portion of the rigid structure is forced to give. This can result in the breakage of the flap or the frame and/or the destruction of the hinge mechanism including but not limited the breakage of the shafts or the hinge tubes, the separation of the hinge from the flap or the frame, the breakage of the cam member, or merely the deformation of the hinge mechanism outside of tolerances resulting in unreliable performance. The same potential for damage often results from the physical construction of the pet door. When the hard flap rotates until it is contact with the top of the frame member, the pivot point is moved from the hinge mechanism to the point of contact between the frame and the flap. This results in lateral (i.e., non-rotational) forces, which a conventional hinge is not designed to accommodate, being applied to the hinge.
A hinge for use in a pet door is shown and described. The hinge mechanism includes a shaft is received by a shock-absorbing bearing. The bearing is received by a sleeve. The bearing rotates within the sleeve to allow pivoting of the flap. In the event of undesirable forces being applied to the hinge mechanism, a deformable and resilient material forming the core of the bearing flexes to prevent damage to or destruction of the hinge mechanism or the pet door.
The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which:
A pet door hinge adapted to tolerate undesirable and potentially-damaging forces occurring within the normal course of operation of the pet door is shown in the figures and described herein. The general construction of a pet door is well known to those skilled in the art and, therefore, are not described in detail herein. Specifically, frames, flaps, closure mechanisms, locking mechanisms, and other common features are deemed to be within the purview of one of ordinary skill in the art. The pet door hinge described herein allows the movement of the flap and provides shock-absorption in the event that undesirable forces, such as lateral or excessive rotational forces, are applied to the hinge mechanism. It will be understood by those skilled in the art that the pet door hinge described herein can be used in various pet doors without departing from the scope and spirit of the present invention.
The void defined by the outer ring 306 is substantially filled with a cushion 308 that is generally secured to the outer ring 306. The cushion 308 is fabricated from a polymeric material that is resilient and deformable, for example, rubber polyisoprene. In one embodiment, the cushion 308 defines a plurality of through-openings that provide room for the deformation of the cushion 308 in the event of the undesirable forces on the hinge 100. The shape, size, number, and position of the through-openings is selected to provide the desired amount of deformation. In an alternate embodiment, the material from which the cushion 308 is fabricated exhibits sufficient compressability to provide the desired deformation without the use of through-openings. Those skilled in the art will recognize other materials which could be used without departing from the scope and spirit of the present invention including closed or open cell foam.
The cushion 308 allow defines an opening adapted to receive the shaft 300. The shaft 300 is generally shaped so as not to rotate within the cushion 308 opening in the presence of normal operating forces required to move the flap 102. Typically, any geometric shape having corners tends to resist rotation, for example the substantially square-shaped shaft illustrated in the Figures. Although generally deformable, the cushion 308 is fabricated from a material that does not deform under the normal operating forces required to move the flap 102, i.e., while the bearing freely rotates. In the most basic embodiment, the engagement of the shaft 300 and the cushion 308 is in the fashion of a mortise-and-tenon. Other embodiments incorporate additional features such as those illustrated in the Figures.
A further refinement visible in
Herein, the shaft 300 has been shown and described as part of the door flap 102 and the sleeve 310 has been shown and described as part of the door frame 104. It will be understood by those skilled in the art that relative placement of the shaft 300 and the sleeve 310 can be reversed without departing from the scope and spirit of the present invention.
A pet door hinge adapted to tolerate undesirable and potentially damaging forces applied during normal operation of the pet door has been shown and described. The hinge mechanism incorporates a bearing have a core formed from a resilient, deformable polymeric material forming the core of the bearing. The core gives under pressure in order to prevent damage to or destruction of the hinge mechanism or the pet door. Those skilled in the art will recognize the geometric shapes and relative dimensions described herein are exemplary and represent easily moldable parts. Other shapes and dimensions could be used without departing from the scope and spirit of the present invention.
While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.