GB1567001A

GB1567001A - Cat ports

Info

Publication number: GB1567001A
Application number: GB3368475A
Authority: GB
Original assignee: DUNLOP S
Current assignee: DUNLOP S
Priority date: 1976-12-23
Filing date: 1976-12-23
Publication date: 1980-05-08

Description

(54) IMPROVEMENTS RELATING TO CAT PORTS (71) We, JAMES KERR DUNLOP and SHEILA ROSINA DUNLOP, both British Subjects trading as JAMES KERR DUNLOP DESIGN CONSULTANTS of 48., Finchfield Road, Wolverhampton, West Midlands, do hereby declare this invention to be described in the following statement: This invention is concerned with improvements relating to cat ports. The term "cat port" has been used herein as relating to entrances of the kind fitted to houses to cnable a small animal such as a cat to gain access to the house as and when it desires.

Existing cat ports are generally of the kind comprising a door pivotally mounted in an opening which is of a size sufficient to allow passage therethrough of the small animal. The opening may be provided in an exterior wall of the house, but is more often provided in a main exterior door, such as the back kitchen door, and will be described hereinafter in that venue for simplicity.

The door is usually mounted for movement about a horizontal pivot axis extending through an upper part of the opening, parallel to the plane of the main door, in a manner such that the door will drop under its own weight into a generally vertical disposition to close the opening, but such that it can be moved, by pressure applied to a lower part thereof, in either direction to allow the cat to pass to and from the kitchen.

Whereas it is normal to provide a manual iy operated lock on such a cat port, to be effective the cat port must be capable of being opened by the small animal as and when it pleases. Unfortunately, it is not uncommon for neighbouring cats, particularly strays, to learn to use a cat port, and to follow a cat through the port into the kitchen. This can have undesirable consequences.

This invention provides a cat port comprising an opening, a door pivotally mounted in the opening, and a catch mechanism, the catch mechanism being movable from an operative condition, in which a latch member thereof restricts opening movement of the door in at least one direction, to an inoperative condition in which said latch member does not so restrict such opening movement of the door, the catch mechanism being normally urged to its operative condition, and being adapted to be rendered inoperative in consequence of the positioning of an operator in the opening.

The operator is conveniently provided by a device which may be worn around the neck of the cat to whom passage through the port is intended to be permitted. The catch mechanism may be rendered inoperative, in consequence of such positioning of the operator, by mechanical means: thus the latch member may be attached to an arm pivotally mounted on a horizontal pivot in a base of the port, said arm being counterbalanced to an extent such that the latch member, when the mechanism is at rest, adopts a latching position, and the operator may be provided by a small magnet. On entrance of the cat into the opening the juxtaposition of the operator with part of the catch mechanism may cause the catch mechanism to be moved to its inoperative condition.

The cat may then press against the door, and cause the door to open in the normal way. Advantageously, means is provided to ensure that, subsequent to the cat passing from the cat port, the latch member retains the door in its closed position.

Preferably the said one direction in which the latch member restricts opening movement of the door is inwardly of the house, movement of the door in the opposite direction, allowing the cat to leave the house, being unrestricted.

The magnetic interaction between the operator and the catch mechanism is conveniently effected by fully counterbalancing the latch member with a permanentlymagnetic responder, and by the provision, as operator, of a permanent magnet. Conveniently, the operator is freely suspended from the collar of the cat, such that when the cat partly enters the opening, the operator will adopt an orientation commensurate with its attraction with the responder, the upward forces on the responder altering the stability of the catch mechanism and causing the latch member to adopt its non-latching position.

Since the distance between the responder and the operator may be made quite small (i.e. in the order of 1 or 2 inches or less) the strength of the magnet required for the operator may be quite small, since the strength of the magnet providing the responder may be comparatively large.

However, if desired, the operator may be passive, i.e. in the form of a material of high magnetic permeability and low or zero remanence, such as soft iron.

Alternatively, the catch mechanism may be rendered inoperative in consequence of the positioning of an operator in the opening, by an electric control device. Thus, a battery-operated control device may comprise a circuit which includes a switch (for example a butterfly switch), which is normally open, and the operator similarly provided by a small magnet. The butterfly switch will preferably be so located that, on entrance of the cat into the opening, the juxtaposition of the operator with the butterfly switch will cause the switch to close, in consequence of which the control device renders the catch mechanism inoperative for a specific limited period of time (e.g. 1 to 2 seconds), whereupon the catch mechanism returns to its operative position, to reengage and hold the door closed as it falls behind the cat. The butterfly switch will return to its open condition as the cat passes through the opening, and in this way power drain on the battery may be retained very low.

Alternatively, where electric power derived from a mains supply is available (e.g., from a bell transformer) other forms of control device may be utilised.

For example, the operator may be in the form of a metal dog-tag worn around the cat's neck, conveniently being of soft metal such as iron. A coil may be looped around the opening, and the control circuit may cause the coil to be continuously energised, and comprise means for detecting the change of inductance in the coil as will occur in consequence of the positioning of the operator in the opening.

There will now be given a detailed description, to be read with reference to the drawings, of a cat port which is a preferred embodiment of this invention. It is to be understood that this embodiment has been selected to illustrate this invention by way of example.

In the drawings accompanying the provisional specification: Figure 1 is a vertical sectional view of the cat port which is the preferred embodiment of this invention; Figure 2 is a perspective view of said cat port; Figure 3 is a view similar to that shown in Figure 2; a base cover having been removed to show catch mechanism of the cat port; Figure 4 is a schematic side sectional view of the catch mechanism in an operative condition; Figure 5 is a view similar to that shown in Figure 4 with the catch mechanism in its inoperative condition; and Figure 6 is a front elevation of a frame of the cat port.

The cat port which is the preferred embodiment of this invention is adapted to be mounted in an opening 4 of a main door 2, and comprises a frame 6 comprising a generally circumferentially-extending wall 8 adapted to be seated against a surface of the door bounding the opening 4, and a radiallyextending flange 10 defining an aperture 12 of the cat port.

The frame 6 is moulded from plastics material, and the flange 10 is provided with screw holes whereby the frame may be secured to the door 2 on the inner side thereof; on the outside of the door 2, an annular flange 14 will be secured to the door around the wall 8, to provide a neat finish to the cat port.

Mounted within the aperture 12, for movement about a horizontal pivot 18 lying generally parallel to the plane of the main door 2 is a cat door 16, conveniently moulded from a translucent material, or a transparent material such as "Perspex" (Registered Trade Mark). The pivot 18 being located in an upper part of the aperture 12 whereby the door 16 will swing, under its own weight, into a vertical position (shown in Figure 1) in which the door 16 closes the aperture 12.

Secured to the inner side of wall 8, one either side of a central, lowermost portion thereof, are two base parts 20,20 bounding an enclosure 22. Located within the enclosure 22 is catch mechanism of the cat port, said catch mechanism comprising an arm 24 mounted on a horizontal pivot 25 extending widthwise of the aperture 12, a latch member 26 upstanding from one end of the arm 24, and a responder 28 mounted on the other end of the arm. The weight and positioning of the latch member and responder are such that the latch member is overbalanced, and, at rest, projects through an opening 32 provided in a base cover 30 (see Figure 4), the latch member 26 thus adopting a latching position, corresponding to an operative condition of the catch mechanism.

The responder 28 is provided by a permanent magnet, whose polarity is disposed generally vertically: thus, the responder is adapted to be magnetically attracted in a generally upward direction by the passage, across the base cover 30, of an appropriate Iy-polarised permanent magnet, or a body of soft iron.

The extent of overbalancing of the latch member 26 by the responder 28 is minimal, and thus a small degree of upwardlydirected magnetic force on the responder 28 may be sufficient to cause the arm 24 to move anti-clockwise about its pivot 25, lowering the latch member 26 into a nonlatching position (as shown in Figure 5) causing the catch mechanism to be rendered inoperative.

The cat port which is the preferred embodiment of this invention is adapted for use in conjunction with an operator adapted to be supported by a collar worn by the cat, and which is capable of being magnetically attracted towards the responder 28.

The operator may be in the form of a bar magnet, suspended at a central point to allow, on partial entry of the cat into the aperture 12, said bar magnet to be orientated into a direction in which it is attracted towards the responder 28. On subsequent movement of the latch member into its non-latching position, the cat may press against the lower part of the door 16, causing said door to move in a clockwise direction about the pivot 18, allowing the cat to pass through the aperture 12 and into the house. Immediately subsequently, the door 16 moves in an anti-clockwlse direction under its own weight towards its closed position, the door engaging a cam surface 27 of the latch member 26 to cause the latch member to be momentarily moved to its non-latching position, the latch member subsequently returning to its latching position behind the door 16 (see Figure 1).

Alternative to the operator being provided by a bar magnet, the operator may be provided by a bar of soft iron, which will be attracted by the responder 28, similarly causing the pivot arm 24 to be moved anti-clockwise about the pivot 25. This has the advantage that the cat is not obliged to wear a perpanent magnet, which might have the disadvantage of attracting small pieces of iron and the like.

Alternative to the catch mechanism being moved to its inoperative position by simple mechanical means, a control circuit may be used, comprising e.g. an amplifying device of the kind wherein, on positioning of an operator in the opening, magnetic interaction between the operator and a responder of the catch mechanism causes the catch mechanism to be rendered inoperative through an intermediate stage of amplification; thus, the operator may be in the form of a very weak magnet and the responder may be in the form of a magnetic switch caused to close by the proximity of the operator to cause the latch member to be moved to its non-latching position by energisation of a solenoid or the like. Alternatively, a coil may surround the opening of the cat port, and the control circuit may release the catch mechanism by detecting change in the inductance in the coil.

WHAT WE CLAIM IS: 1. A cat port comprising an opening, a door pivotally mounted in the opening, and a catch mechanism, the catch mechanism being movable from an operative condition, in which a latch member thereof restricts opening movement of the door in at least one direction, to an inoperative condition in which said latch member does not so restrict such opening movement of the door, the catch mechanism being normally urged to its operative condition, and being adapted to be rendered inoperative in consequence of the positioning of an operator in the opening.

2. A cat port according to Claim 1 wherein the catch mechanism is rendered inoperative by mechanical means.

3. A cat port according to Claim 2 wherein the operator is in the form of a magnet, and the latch member is moved to permit opening of the door in consequence of magnetic attraction between the operator and part of the catch mechanism.

4. A cat port according to Claim 1 wherein movement of the catch mechanism from its operative condition to its inoperative condition is controlled by an electrically-operated control circuit.

5. A cat port according to Claim 4 wherein the control circuit comprises a normally-open switch which is moved to a closed condition, in consequence of the positioning of the operator in the opening, closure of said switch causing energisation of a solenoid, which causes the latch member to move to permit opening movement of the door.

6. A cat port according to Claim 5 wherein the control circuit is closed by the inter-position of a magnetic operator in the opening.

7. A cat port according to any one of claims 4, 5 and 6 wherein the control circuit is or is adapted to be battery-operated.

8. A cat port according to Claim 4 wherein the control circuit is adapted to be operated by electrical power derived from a mains circuit.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. an opening 32 provided in a base cover 30 (see Figure 4), the latch member 26 thus adopting a latching position, corresponding to an operative condition of the catch mechanism. The responder 28 is provided by a permanent magnet, whose polarity is disposed generally vertically: thus, the responder is adapted to be magnetically attracted in a generally upward direction by the passage, across the base cover 30, of an appropriate Iy-polarised permanent magnet, or a body of soft iron. The extent of overbalancing of the latch member 26 by the responder 28 is minimal, and thus a small degree of upwardlydirected magnetic force on the responder 28 may be sufficient to cause the arm 24 to move anti-clockwise about its pivot 25, lowering the latch member 26 into a nonlatching position (as shown in Figure 5) causing the catch mechanism to be rendered inoperative. The cat port which is the preferred embodiment of this invention is adapted for use in conjunction with an operator adapted to be supported by a collar worn by the cat, and which is capable of being magnetically attracted towards the responder 28. The operator may be in the form of a bar magnet, suspended at a central point to allow, on partial entry of the cat into the aperture 12, said bar magnet to be orientated into a direction in which it is attracted towards the responder 28. On subsequent movement of the latch member into its non-latching position, the cat may press against the lower part of the door 16, causing said door to move in a clockwise direction about the pivot 18, allowing the cat to pass through the aperture 12 and into the house. Immediately subsequently, the door 16 moves in an anti-clockwlse direction under its own weight towards its closed position, the door engaging a cam surface 27 of the latch member 26 to cause the latch member to be momentarily moved to its non-latching position, the latch member subsequently returning to its latching position behind the door 16 (see Figure 1). Alternative to the operator being provided by a bar magnet, the operator may be provided by a bar of soft iron, which will be attracted by the responder 28, similarly causing the pivot arm 24 to be moved anti-clockwise about the pivot 25. This has the advantage that the cat is not obliged to wear a perpanent magnet, which might have the disadvantage of attracting small pieces of iron and the like. Alternative to the catch mechanism being moved to its inoperative position by simple mechanical means, a control circuit may be used, comprising e.g. an amplifying device of the kind wherein, on positioning of an operator in the opening, magnetic interaction between the operator and a responder of the catch mechanism causes the catch mechanism to be rendered inoperative through an intermediate stage of amplification; thus, the operator may be in the form of a very weak magnet and the responder may be in the form of a magnetic switch caused to close by the proximity of the operator to cause the latch member to be moved to its non-latching position by energisation of a solenoid or the like. Alternatively, a coil may surround the opening of the cat port, and the control circuit may release the catch mechanism by detecting change in the inductance in the coil. WHAT WE CLAIM IS:

1. A cat port comprising an opening, a door pivotally mounted in the opening, and a catch mechanism, the catch mechanism being movable from an operative condition, in which a latch member thereof restricts opening movement of the door in at least one direction, to an inoperative condition in which said latch member does not so restrict such opening movement of the door, the catch mechanism being normally urged to its operative condition, and being adapted to be rendered inoperative in consequence of the positioning of an operator in the opening.

9. A cat port according to one of claims

4 and 8 comprising an inductance loop extending around the opening, the catch mechanism being rendered inoperative in consequence of the positioning of the operator in the opening, by detection by the control circuit of a change in the inductance of said loop.

10. A cat port constructed and arranged substantially as hereinbefore described in reference to the drawings accompanying the provisional specification.