Field of Invention

The present invention relates to an animal access door, more particularly a pet security doors, typically found on exterior doors in domestic dwellings.

Background of Invention

Pets, in particular cats, have long been allowed to more or less freely enter and exit the homes of their owners, in order that for example they can keep the hours they want, visit the outside to attend to their ablutions and generally lead a less restrained and more carefree existence. In past times this meant an open door. Nowadays more specific means are available to prevent undesirable people or animals entering the owners' homes.

Prior Art

Nowadays to permit the entry and exit of for example cats, many doors are perforated with a hanging flap, typically made from a synthetic plastics material, and hinged at its top, known commonly as a 'cat flap' although models for other animals are possible such as dogs.

Such a cat flap swings generally in two directions to permit an animal to enter and/or exit through an otherwise closed and locked door. Existing cat flaps allow security to the owner, as they are, by virtue of their small size, unlikely to permit the ingress of humans, undesirable or otherwise. The cat flap is typically held in place and hinged to a surrounding moulding, which corresponds to a hole cut in the door at an animal's height.

This moulding or frame often has a facility for an animal's owner to prevent swinging movement of the flap, and therefore the access point created by the cat flap. This can be is used to prevent access in one or both directions when required. This may be as simple as a thumb lock that is pushed across to block movement of the flap.

Such a facility or mechanism allows an animal's owner to prevent movement of the animal in one or both directions as required. For instance the owner may wish the animal to stay indoors for a certain period, say overnight, and/or additionally may wish to prevent other animals entering their premises during the night.

The applicant's previous UK Patent Application GB-A-2 381 180 (Chamberlain) discloses an animal access system comprising an access door, sensor means and operates in conjunction with a sub-dermal implant; the system being such that in use the implant identity device is detected by the sensor so as to permit access to an authorised animal only.

The invention described in the Applicant's aforementioned UK Patent Application allows the animal's owner to regulate the movement through the door of specified animals as well as at specified times. Animals not specified by the owner for entry may be blocked from access through the cat flap, or access door. The reasons for such a facility range from the concern over other animals entering the owner's home, through theft of the owner's or pet's food to bullying and intimidation of the owner's pet.

An example of another animal access system is described in US Patent Application 2007/0227462 (Huff), which discloses a window for a gate having a transparent viewing area and a border area for inclusion in a fence or gate. The window is intended to prevent children from poking their fingers through the window.

In US Patent US 7 284 502 (Dotter) a decorative surround for a pet access door is described. The decorative door panel is arranged to cover the frame of an animal access door by sliding into groves in the surround. Although the owners of animals may control events, for example the opening of the flap or door to the exterior of a house, the animal itself does not always have knowledge of what awaits it on the other side and this has sometimes caused the animal trauma. For example if an aggressive or dominant animal awaits it, for example in order to intimidate it, an animal might inadvertently venture out of a house and be confronted by a larger or aggressive animal which may give rise to trauma.

The present invention arose in an attempt to overcome this problem and seeks to provide an improved pet security or animal access door.

Summary of the Invention

According to a first aspect of the invention there is provided an animal access door for use between a first space and a second space, the door in use having a portion enabling vision when viewing from the first space to the second space and adapted to inhibit vision when viewing from the second space to the first space.

Ideally the first space is an interior of a dwelling and the second space is the exterior of a dwelling, such as a porch or garden.

In a preferred embodiment the door includes a hinged flap and the flap is set into a frame. Ideally the frame has a recess with a larger entry point and exit from an interior to an exterior of a building. The recess may be in the access door or the frame.

Alternative embodiments may be provided which are supplied separate from the access door, for example for fitting to the door or elsewhere.

In another embodiment a pet is able to view from the interior of a house to the exterior - and is provided with a good view of what is outside of the door. This is achieved as a result of an obscuring means that is placed intermediate the eye of a viewing animal, located within the house and the portion enabling vision.

The obscuring means may be a fish-eye or peep hole permitting one way viewing or it may be a portion of transparent material with a half-silvered surface.

In another preferred embodiment the side from which vision is permissible (that is the side on the interior of the door or building) may be fitted with a one-way mirror or a privacy film that prevents or inhibits vision from the exterior to the interior of the door.

In a yet further embodiment a smoked or coloured transparent material may be used so as to reduce the amount of light inside the building thereby creating a naturally darker or shaded region so as to inhibit the view from a relatively bright outside environment to the darker interior.

The means used of enabling vision through the door in one direction whilst inhibiting, reducing or denying vision in the other in some embodiments may comprise uni-directional glass, Perspex (Trade Mark), a synthetic rubber compound or plastics material. Such materials include one or more mirrored surface(s) on one direction of access or one side of a transparent door, which enables darkened vision through the door from the outside in.

In alternate embodiments the door may be slatted with the slats angled down towards the non-enabled side (exterior of a building). In a yet further embodiment the door may be constructed of a switchable privacy glass of plastics material, wherein the door may be adjustable to user requirements.

A tinted door functions by suppressing the penetration of visible light by the glass itself, whereby the privacy of the first or interior space is attained.

In a further alternative embodiment the glass or transparent medium may be switchable from a viewing (transparent) state to a non-viewing (opaque) or reflective state, such as by way of an electrically operated medium whose opacity can be varied by an electric field.

Preferably the reflectivity and/or transparency of the portion enabling vision is switchable from the viewing (transparent) state to the non-viewing (opaque) or reflective state which is achieved in dependence upon receipt of a signal indicative of the identity of the animal. Thus for example a radio frequency identity (RFID) tag, implanted sub-dermally in the animal, emits a signal which, if corresponding to an authorised animal, permits access as well as switching the transparency of the window or viewing panel.

The switching can be achieved using a liquid crystal device (LCD), a polariser or a photovoltaic layer, whose optical properties vary in dependence upon an applied electric field. In an alternative arrangement the aforementioned slatted shutters may be displaced from a closed state to a relatively open state thereby defining a transparent portion permitting vision therethrough. In this configuration the slatted portions are ideally enclosed in a transparent protective housing.

An arrangement that reduces vision in one or both directions also helps decrease heat transfer. This may be useful in doors facing direct sunlight or in situations where the door is situate in a porch area prone to colder conditions or overheating, or is exposed to prevailing weather conditions, and behind which the animal is confined.

The transparent portion may be constructed of corrugated plastics, alone or in combination with a tint or other means of obscuring vision, such as an intermediate level of opacity or a specific colour.

In further embodiments a so-called fish-eye wide-angle or convex lens may be used to afford maximum vision from the interior to the exterior of the building. Such an optical arrangement allows a wider field of view from the interior and little visibility from the exterior of a building. This optical arrangement may be set into the door, or set into a location proximate to the door. A support frame may provide space for situating such a lens such that it remains stable and easy for an animal to use. One example of such a lens is a Fresnel lens which is cheap to manufacture and may be formed from synthetic plastics material or glass, the former being he preferred cheaper alternative

The lens may combine with an electronic means of obtaining and relaying images from the exterior of the door to the area. In such a combination an animal who has become accustomed to watch the area on a screen or display, so as to check before exiting the pet access door. Such an arrangement may be used in combination with a motion sensor so as to automatically display anything that is present outside the pet access door. The electronic means of obtaining and relaying images from the exterior of the door ideally comprises a camera, which ay e an infra red camera.

A motion sensor may be situated in the second space allowing it to activate when animals or motion is detected in the area. In addition a motion sensor may be situated in the first space, to activate when an animal or motion is detected, allowing an animal to look through the area for instance by illuminating a screen. In the alternative a motion senor may be activated by motion in one of both of the spaces.

In further embodiments, motion sensors may be provided to activate lighting in the second (exterior) space.

In a particularly preferred embodiment a displaceable flap is formed from a plastics material with a mirrored side on the exterior and gradated ridges forming a convex surface. In this manner the flap enables a wider angled vision of the exterior of the door whilst preventing an animal on the exterior of the door from obtaining sight of the interior. In addition the door prevents unwanted observers such as thieves from looking through the door. Different sizes and styles may be available of the transparent portion, in line with different sizes and styles of the door, so as to have the same appearance as, for example, glass doors.

Preferred embodiments of the invention will now be described, by way of example only, and with reference to the Figures in which:

Brief Description of the Figures

Figure 1 shows a side perspective view of an embodiment of the device in use;

Figure 2a shows a view experienced by the cat of the device in use;

Figure 2b shows a view experienced by the cat, corresponding to the view in Figure 2a;

Figure 2c is a diagrammatical section of one example of the animal access door, its component parts and a screen in a transparent state;

Figure 2d is a diagrammatical section of the animal access door and a screen in a reflective state;

Figure 3 shows a front elevation of a transparent portion, which is in the form of a Fresnel lens, of an alternative embodiment to that shown in Figure 1 ; and

Figure 4 shows an overall view of an alternative embodiment of an animal access door, which may be incorporated with the embodiment included as part of a system, and shows a display within the house and an imager outside the house.

Detailed Description of Figures W

Referring to Figures 1 and 2, there is shown an embodiment of an animal access door 1 having a transparent portion 2, enabling vision from one (interior) space 3, such as a kitchen, to a second (exterior) space 4, such as a garden or patio, whilst inhibiting vision in the reverse direction (4 to 3). The door 1 includes a hanging flap 6 secured in a frame 7 at a convenient height for animals 10 to enter.

The unwanted animal (here pictured as an angry dog 20) in the exterior space 4 is unable to see through the transparent portion 2 of the door 1 ; instead seeing a reflection of itself (Figure 2b) in a one-way mirror or smoked glass disposed in the hanging flap 6.

The mirrored or one-way surface of the transparent portion 2, defines the majority of the flap 6 to the exterior of the door 1. This means that a potentially hostile animal 20, in the exterior space 4, cannot see into the interior space 3 and so will be confused by its own reflection into thinking there is no door 1 , and hence will not wait for the pet (pictured as a cat 10) to exit.

As shown in Figure 2a, the mirrored surface of the transparent portion 2, has advantages in that it provides a surface that inhibits vision through the door 1 from the exterior 4 to the interior 3 whilst enabling vision from the interior through the door 1. This is emphasised in Figure 2b, which shows the view from the outside.

However, for other priorities, a tinted enabling portion may be preferred, relying instead on the relative light levels from exterior 4 to interior 3, which will predicate that vision is inhibited from exterior 4 to interior 3, particularly during the more busy daylight hours.

Optionally there may be provided a solar powered illumination source (not shown) to help illuminate the exterior space 4 in order to promote the inhibition of vision from the exterior 4 to the interior 3. The embodiment of the door 1 shown in Figures 2a, 2b and 2c has a sensor, such as a microchip scanner 9 which reads an implanted radio frequency ('RFID') microchip, of the type that are commonly implanted in domestic animals. The scanner 9 allows for permitted animals 10 to have their microchip details and identifications stored in the microchip scanner 9, whereby the microchip scanner 9 scans the animal and determines, by way of a microprocessor 28, whether the animal is authorised and if so, permits access through the door by sending a signal to a solenoid (not shown) thereby permitting flap 6 to open so granting access to the animal, which is typically a cat. An audible sound, such as a peep, may accompany the releasing of the solenoid so indicating to the cat that the flap 6 is open and so access into the house (interior space) 3 may be gained.

Referring to Figures 2b, 2c and 2d, there is shown a further embodiment of the security door 1 which includes a microprocessor controlled, switchable panel 40. Panel 40 includes a liquid crystal material that is sandwiched between first and second transparent protective layers 42 and 44. A transparent window 46 is provided for strength. The transparent window 46 may comprise a lens or other optical device for modifying an image as viewed from one side or the other.

When an authorised cat is detected, the microprocessor sends two signals: a first releases the flap 6, (that is suspended on a pivot 33) for example by way of a solenoid (as mentioned above); and a second signal applies an electric field to a liquid crystal device (LCD) or activates another enabling mechanism, such as a shutter opening system (not shown). Alternatively the opening system includes a switchable polariser, or other conductive layer such as, indium tin oxide (ITO), which is activated may be used. What is notable is that the portion enabling vision varies its transparency or reflectivity, thereby permitting the animal to view only in one direction through the window or viewing panel in a similar manner to a one-way mirror.

Figure 4 shows an overall view of an alternative embodiment of an animal access door, which may be incorporated with the embodiment included as part of a system or may be used as a stand-alone warning system alerting an owner or their pet to the presence of an undesired animal. Figure 4 shows an active display 50 within the house and an imaging device 60 outside the house. Optionally an animal access door 1 used between a first space 3 and a second space 4, the door 1 in use having a portion 2 enabling vision when viewing from the first space 3 to the second space 4 and adapted to inhibit vision when viewing from the second space 4 to the first space 3.

Figure 4 shows a portion 2 enabling one way vision, fitted in the door 1 , wherein the portion 2 may be supplied and/or fitted separately to the door 1. In this embodiment the portion is a convex lens and provides a wide view of the exterior space 4 for the animal 10 to survey before it commits to use of the door 1. Alternatively, or in addition to the aforementioned convex lens a switchable screen (of the type shown in Figures 2c and 2d may be incorporated in the door.

The embodiment shown in Figure 4 further includes a microchip scanner 90, a timer 80, connected to a microprocessor 28 and an image or motion sensor 60, such as a pixellated infra red (PIR) device or solid state imager (charge coupled device (CCD) or like arrangement) for detecting the approach of animals.

The image or motion sensor 60 relays a signal to microprocessor 28 which in turn activates a driver circuit (not shown) that switches a liquid crystal material, polariser or other like material (whose optical characteristics vary as a result of an electro-magnetic field) so as to render the portion enabling vision transparent or opaque.

Optionally a light 100 is activated in the dark by the approach of an animal and this permits the pet 10, viewing form inside, to see through the one-way door 1 and/or to assist a viewer inside the house to see the animal by way of a camera, as described below. As well as motion sensors, negative stimuli may be provided by the microchip scanner 9 when it detects an animal 20 that is not permitted to access the door 1.

In the event of an approach by an unauthorised animal, whose presence may be detected by imager or motion detector 60 and/or by an RFID detector, an audible alarm (not shown) may be triggered to alert this to the cat (or owner) inside the dwelling. Alternatively, or in addition to this, a display presents an image of what is viewed by the video camera 60, which may be positioned so that the pet 10 as well as its owner (not shown) may view what is outside the door. Optionally an audible alarm may sound when the presence of something moving is detected. Upon hearing the alarm, the cat is alerted to this fact and on approaching the door is confident that the unauthorised animal cannot see it.

In further embodiments, the RFID sensor or microchip scanner 9 may provide illumination, for example by way of an externally located light source 100, after sensing an unauthorised animal 20.

Figure 3 shows a detailed construction of an example of a flap 6, including transparent portion 2, wherein the transparent portion is constructed with a series of concentric lenses forming varying depth of ridges. The eccentricity of the ellipses and the varying depths of ridges that define the lenses help form a type of lens, known as a Fresnel lens.

A Fresnel lens allows the owner of the animal 10 a wider view of the exterior space 4 from the interior 2 and may be combined with other means of obscuring and inhibiting vision from exterior 4 to interior 3. In this way animal 10 may be secure that no threatening or aggressive animal 20 is on the other side of the door 1 or in the environs.

The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of invention. With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, is to include variations in size, materials, shape, form, function and manner of operation, assembly and use, and all are deemed readily apparent to one skilled in the art, and all equivalent relationships to those illustrated in the drawings, and described in the specification, are intended to be encompassed by the present invention.

It is also understood that supply of the transparent portion (together with requisite fittings) suitable for retro-fitting to existing pet access doors, is within the scope of the invention, so as to render them suitable for use as a pet access door that enables viewing from a first side of the door to a second side of the door and inhibiting viewing from the second side of the door to the first side of the door.

Therefore, the foregoing are considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.