Patent Application
20080283513
Not Applicable
Not Applicable
1. Field of Invention
The present application relates to a heating pad for an animal. More specifically, the present application relates to a heating pad for use with an animal bed.
2. Description of the Related Art
Many house pets, especially dogs and cats, find a heated bed or blanket pleasing on which to lie. Thus, electric heating pads have been used for warming pet beds for some time. One problem that occurs when using a conventional heating pad is that a pet can fold or bunch-up the heating pad. Folding or bunching a heating pad increases the risk that the heating pad will overheat because the heating elements are then concentrated in a smaller area with more layers of insulation preventing the heat from escaping. While it is known to incorporate temperature limiting devices, such as a thermostat, into a heating pad in order to reduce the likelihood of overheating, such solutions are incomplete because of the uneven distribution of temperature within the heater elements, creating “hotspots.” Depending on the design and materials, heating pads which overheat are subject to failure resulting in damage to the components of the heating pad and risk of becoming a fire or electrical hazard.
The following patents and published applications are typical of the heating pads found in the prior art:
It is quite common for an animal to turn several times before lying down to shape the area. Generally, the prior art heating pads and heated pet beds are constructed using pliable materials which can be easily folded or bunched by an animal moving on or about the prior art heating pads thereby creating hotspots. Some of the prior art heating pads and heated pet beds use securing mechanisms to secure the edges in an attempt to prevent folding or bunching. An example of such is found in U.S. Pat. No. 6,237,531, issued to Peeples, et al. However, should the securing mechanism not be engaged or become disengaged, the heating pad or heated pet bed is then subject to folding or bunching and the resulting dangers of hotspots and overheating. U.S. Pat. No. 6,084,209, issued to Reusche, et al., describes a heated pet bed that prevents folding by forming a rigid outer casing having six sides in which the heating element is housed. However, the heated pet bed described by Reusche, et al., is not easily transportable and is less comfortable due to rigid housing.
A heating pad for use with animals, or pet heating pad, is summarized below without intending to limit the invention. The pet heating pad provides a pad with a cushioned exterior and a flexible but resilient interior that prevents overheating by maintaining or returning the pet heating pad to a flat profile. The pet heating pad heating system includes a heating element with temperature limitation controls for safe operation surrounded by layers of material selected for temperature control properties. The pet heating pad substantially reduces or eliminates the problems normally associated with heating pads such as hotspots, overheating, bunching, and folding while providing a pet with a physically and thermally comfortable surface upon which to rest.
Generally, the pet heating pad includes a heating element, one or more fixing layers, one or more cushioning/insulating layers, and one or more shaping layers, all arranged within a shell. Optionally, the pet heating pad also includes one or more thermal distribution layers. The function layers of the pet heating pad may be implemented in combination in a single physical layer or split into multiple layers to accommodate various design concerns.
At the core of the pet heating pad is a heating element. The heating element is heater wire restricting the flow of electricity and producing heat. The heater wire is arranged to fill a selected area of the pet heating pad with a selected separation between the parallel legs of the heating element and shaped to match the desired shape of the pet heating pad. The even distribution of the heater wire throughout the selected area provides an even temperature distribution. For safety, the heating element includes one or more thermostats, limiting the maximum temperature of the heating element, and fuses limiting the amount of current drawn through the heating element. The fixing layers have adhesive on the sides engaging the heating element. The adhesive secures the heating element to the fixing layer, which prevents the electrical components of the heating element, in particular the heating wire, from moving and bunching up and creating hotspots or an uneven temperature distribution. The thermal distribution layers are fabricated from a thermally-conductive material to further enhance the evenness of the temperature distribution by conducting but not storing heat when the thermally-conductive material is placed proximate to or in direct contact with the heating element. The cushioning layer is positioned above the heating element/fixing layer assembly such that the heating element does not make a pet resting on the pet heating pad uncomfortable, either physically and/or thermally. More specifically, the cushioning layer provides physical comfort for the pet by reducing or eliminating the perception of any hard or sharp components in the heating element and provides thermal comfort for the pet by sufficiently insulating the pet from the heating element to provide comfortable warmth over extended periods of time without the surface of the pet heating pad becoming uncomfortably warm. The pet heating pad also includes one or more resilient, semi-flexible support members that are substantially planar when at rest. The support members have sufficient rigidity to prevent folding or bunching of the pet heating pad while remaining sufficiently flexible to conform to the shape of the pet under normal usage by a pet or to be bent or rolled under intentional stress such as might be applied by the pet owner. By preventing the folding or bunching of the heating pad, the support member reduces or eliminates the risk of overheating or hot spots common to conventional heating pads. Further, the support members have sufficient elasticity or resilience to return to the substantially planar resting position when stress is removed. The shell defines the outer surface for the pet heating pad and encases the other layers. The shell is generally fabricated as a two-piece assembly with the two pieces being closed, joined, or sealed together.
The above-mentioned features will become more clearly understood from the following description read together with the drawings in which:
A heating pad for use with animals, or pet heating pad, is shown in the figures and described herein by the reference numeral 100. The pet heating pad provides a pad with a cushioned exterior and a flexible but resilient interior that prevents overheating by maintaining or returning the pet heating pad to a flat profile. The pet heating pad heating system includes a heating element with temperature limitation controls for safe operation surrounded by layers of material selected for temperature control properties. The result is a pet heating pad that substantially reduces or eliminates the problems normally associated with heating pads such as hotspots, overheating, bunching, and folding while providing a pet with a physically and thermally comfortable surface upon which to rest.
For safety, the heating element 102 includes one or more thermostats 106 and fuses 108 inline with the heating wire 104. The thermostats 106 limit the maximum temperature of the heating pad by interrupting current flow through the heating element 102 when a selected temperature is reached. The fuses 108 reduce or eliminate the risk of electrical shock by interrupting current flow through the heating element 102 if current in excess of the current rating of the fuse is drawn through the heating element 102. The heating element 102 is connected to a power cord 110. The power cord 110 delivers power to the heating element 102 from a power source (not shown). Typically, the power source is a transformer that rectifies and/or steps down an ac line voltage to a desired dc voltage suitable for driving the heating wire. In the illustrated embodiment, the heating element includes three heating wire segments connected by two thermostats to form a series heating circuit. Each end of the series heating circuit connects with one of end of the power cord and the fuse is placed inline between the at least one end of the power cord and one end of the series heating circuit. The illustrated power cord terminates with a connector 112 allowing removable attachment to a power source. One skilled in the art will recognize that the number of thermostats, fuses, and heater wire segments can vary without departing from the scope and spirit of the present invention.
On either side of the heating element 102 is a fixing layer 114a, 114b. At a minimum, the fixing layers 114a, 114b have a fixing mechanism such as an adhesive 200 on the sides engaging the heating element 102 and sealing the electrical components of the heating element 102 between the fixing layers 114a, 114b. The adhesive secures the heating element 102 to each of the fixing layers 114a, 114b preventing the electrical components of the heating element 102, in particular the heating wire 104, from moving and bunching up and creating hotspots or an uneven temperature distribution. In one embodiment, either the top fixing layer 114a or both fixing layers 114a, 114b are fabricated from a thermally-conductive material to further enhance the evenness of the temperature distribution, particularly when the thermally-conductive material is placed in direct contact with the heating element. Acceptable thermally-conductive materials include aluminum and other metal having good thermal conductivity. Generally, foils and films are used because the thin layer will distribute but not store much heat and will rapidly heat and cool. Providing the thermally-conductive material with a large surface area also provides rapid heating and cooling with minimal heat storage. In another embodiment, the adhesive layers are simply fabricated from any material suitable as carrier for an adhesive 200. Further, the fixing layer material(s) and the adhesive are selected for the ability to withstand the temperatures encountered due to proximity and/or engagement with the heating element 102. In the illustrated embodiment of
Next, a cushioning layer 116 is positioned above the heating element/fixing layers assembly such that the heating element 102 does not make a pet resting on the pet heating pad 100 uncomfortable physically and/or thermally. In one embodiment, the cushioning layer provides physical comfort for the pet by reducing or eliminating the perception of any hard or sharp components in the heating element 102. In another embodiment, the cushioning layer provides thermal comfort for the pet by sufficiently insulating the pet from the heating element to provide comfortable warmth over extended periods of time without the surface of the pet heating pad becoming uncomfortably warm. Materials suitable for accomplishing both purposes include a selected thickness of foam or cotton batting/wadding. One skilled in the art will recognize other materials suitable for meeting one or both of these comfort concerns.
The pet heating pad 100 also includes one or more resilient, semi-flexible support members 118a, 118b that are substantially planar when at rest. The support members 118a, 118b have sufficient rigidity to prevent folding or bunching of the pet heating pad while remaining sufficiently flexible to conform to the shape of the pet under normal usage by a pet or to be bent or rolled under intentional stress such as might be applied by the pet owner. By preventing the folding or bunching of the heating pad, the support member reduces or eliminates the risk of overheating or hot spots common to conventional heating pads. Further, the support members have sufficient elasticity or resilience to return to the substantially planar resting position when stress is removed. At a minimum, the support members resist bunching as a result of an applied lateral force. Less flexible support members resist folding or rolling of the pet heating pad 100 and require a greater and/or intentionally applied force to overcome the initial resistance to bending, torsion, or rolling. The mechanical properties and fabrication materials of each shaping layer 118a, 118b are individually selectable. In one embodiment having more than one shaping layer, the desired mechanical properties for the shaping layers to resist or prevent bending, rolling, torsion, or folding are specified by a set of overall mechanical response characteristics of the pet heating pad 100 and the shaping layers are selected such that, in combination, the overall mechanical response characteristics are met or exceeded. In such a case, none of the individual shaping layers would necessarily meet the desired overall mechanical response characteristics individually. However, the ability to rely on the combination of shaping layers permits the use of individual shaping layers that are more flexible, form-fitting, or comfortable to the pet. In one embodiment, the support members are fabricated from a polymeric or plastic material such as rigid vinyl or polyester.
Returning to
It should be noted that the embodiment illustrated in
The number and arrangement of layers within the pet heating pad 100 may vary without departing from the scope and spirit of the present invention. Further, the functions of two or more layers may be combined or the functions provided by a single layer may be distributed between two or more layers without departing from the scope and spirit of the present invention. By way of example, one alternate embodiment of the pet heating pad uses a single layer to provide the functionality of both the shaping layer and the fixing layer by adhering the heating element to a flexible, substantially rigid, and resilient layer. In another embodiment, the functions of the cushioning layer are accomplished using two different layers—one for thermal insulation and another for making the pet heating pad a soft resting place. In another embodiment, a cushioning layer is placed on both sides of the heating element. In another embodiment, the shaping layer is located between the cushioning layer and the heating element. In another embodiment, no layer having thermal conduction properties is used. These alternate embodiments are not intended to be exhaustive or otherwise limit the scope of the pet heating pad described herein.
For use with pet beds that do not have walls, the pet heating pad may include a securing mechanism that allows the pet heating pad to remain attached to and properly positioned in relation to the pet bed. One suitable attachment mechanism is one or more straps or tie-downs which are releasably secured around the pet bed using knots, snaps, clasps, buttons, buckles, binders, hooks-and-loops, and/or other similar mechanisms. In one embodiment, the straps or ties surround both the pet heating pad and the pet bed and loops or through openings are optionally used to guide or position the straps. In another embodiment, the straps or ties pass through loops or through-openings in the pet heating pad, which serve as tether points and are optionally reinforced, and, thus, only surround the pet bed. In another embodiment, both the pet heating pad and the pet bed have loops or through-openings that provide cooperating attachment points where the pet heating pad and the pet bed are secured together. Another suitable attachment mechanism uses a gripping fastener to secure the pet heating pad to the pet bed. Such fasteners include a hook-and-loop fastener, a clip, or a clamp releasably mating the pet heating pad to the pet bed. More permanent attachment mechanisms involve sewing, riveting, or adhering the pet heating pad and the pet bed together. Another suitable attachment mechanism provides a pocket or compartment, which may optionally be closed using zippers, snaps, buttons, etc., in either of the pet heating pad or the pet bed for receiving the other. Finally, one skilled in the art will recognize that the pet heating pad may be used without a pet bed or provided with sufficient cushioning to serve as a heated pet bed.
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 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 applicants general inventive concept.
