PET DOOR

The present invention relates to a pet door, and in particular to a pet door suitable for use by smaller animals such, as cats and/or larger animals such as dogs.

Pet doors are often fitted in the doors or walls of a building to allow a pet to enter or leave the building without the need for assistance by their owner.

One widely known type of pet door includes a vertically hanging door flap mounted in a support frame, the door flap being pivotably mounted about its upper edge in _. an aperture in the frame so that the door flap is free to pivot about a horizontal axis. It is known to provide such a pet door with a manually operable four-way lock. This lock can selectively be set by a user to one of four positions. In a first position the door flap is completely unlocked and is free to pivot in both rotational directions so as to permit both ingress and egress of the pet relative to the building. In a second position the door flap is completely locked against movement in both directions. In a third position the lock permits movement of the door flap in only one direction, for example to permit egress from, but not ingress into, the building, and in a fourth position the lock prevents movement of the door flap in the other direction, for example to prevent egress from but permit ingress into the building.

A typical four-way lock comprises a manually operable rotary element disposed on one side of the frame, which side is on the inside face of the pet door when the pet door is installed in the building. Radially outwardly extending peripheral parts are provided on the rotary member on both opposite sides of a central section which is aligned with the plane of the door flap when the door flap is closed. The rotary member can be rotated selectively around 360°, and at each of four cardinal directions, which are at 90° to each other, one, two or neither of the radially outwardly extending peripheral parts of the rotary member extend above a lower edge of the door flap and thereby selectively permit or prevent movement of the door flap in the respective direction.

Such a manually operable four-way lock for a pet door is inconvenient to use. The lock must be manually operated and so can only be set to a desired lock configuration by the user when the user is present. Also; the user needs to bend down to the pet door so as manually to operate the lock.

The above-described pet door is a "non-selective" pet door which permits any animal of suitable size to pass through the door when the door flap is unlocked in the respective opening direction as a result of the configuration of the four- way lock. It is also known to provide so-called "selective" pet doors which allow only specific pets through the door. Such selective pet doors include an additional lock mechanism which is only unlocked to allow the animal to pass through the pet door if the animal is carrying an appropriate key. Such selective pet doors can operate using a key worn by the pet which operates a latch in the frame which is unlatched when the correct key is in the vicinity of the frame. The key can operate using a magnetic field, or by emitting radiation such as infrared radiation or ultrasonic radiation.

It is known from GB-A-2334067 and US-A-6141911 to provide a selective pet door having a pair of electrically operate bolts that can be selectively operated to engage within respective sides of a door flap to lock the pet door. However, no four-way locking is disclosed, and so the pet door can not be configured to permit movement of the door flap in only one direction, for example to permit egress from, but not ingress into, the building.

Such selective pet doors are generally more complicated and expensive than nonselective pet doors and require the pet to carry an appropriate key.

The present invention aims to provide a pet door which at least partially addresses and solves the disadvantages of the known pet doors described above.

The present invention accordingly provides a pet door comprising a frame having an aperture, a door flap pivotally mounted in the aperture, at least one locking mechanism including an electrically operable actuator for selectively locking the door flap, and a

control unit which is adapted to operate the at least one locking mechanism, wherein the control unit is removably connected to the frame.

Preferably, the frame is provided with a cavity and the control unit is removably housed in the cavity.

Preferably, the control unit comprises a programmable timer for selectively operating the at least one electrically operable actuator.

Preferably, the control unit further comprises a display for displaying time and a plurality of manually operable controls for programming the control unit.

Preferably, the frame is configured whereby a portion of the frame conceals the manually operable controls when the control unit is connected to the frame.

Preferably, the control unit is programmable by operation of the manually operable controls when the control unit is remote from the frame, and the control unit adapted to control the first and second electrically operable actuators after the control unit has been connected to the frame.

Preferably, the control unit and the frame are respectively provided with complementary first and second electrical connectors which electrically connect the control unit to the at least one electrically operable actuator when the control unit is connected to the frame, and are separable to permit the control unit to be removed from the frame.

The pet door may further comprise detecting means to detect when the control unit is connected to the frame.

Preferably, the detecting means comprises a pair of third electrical connectors in the frame electrically connected together form a short-circuit loop therebetween and a pair of fourth electrical connectors in the control unit for connecting to the third electrical

connectors whereby the control unit can detect from the short circuit when the control unit is connected to the frame.

Preferably, the detecting means is adapted to cause the control unit to control the at least one electrically operable actuator thereby to move a respective locking member into a correct programmed locked or unlocked position for the current time when the control unit is connected to the frame.

Preferably, the control unit is adapted to detect a current state of the at least one electrically operable actuator.

Preferably, the control unit is adapted to set a time period during which at least one locking mechanism is selectively locked or unlocked.

Preferably, the control unit is adapted to provide a manual override whereby the at least one locking mechanism can be set to an unlocked configuration.

Preferably, the or each locking mechanism comprises a motor as the respective electrically operable actuator, a motor arm connected to an output shaft of the motor, a cam member connected to the motor arm and a reciprocable bolt connected to the cam.

Preferably, the reciprocable bolt is caused to reciprocate between locked and unlocked positions as a result of rotation of the motor shaft in respective opposite rotational directions.

Preferably, the frame includes a guideway in which the reciprocable bolt is received for sliding movement along the guideway.

Preferably, the at least one locking mechanism comprises a first locking mechanism and a second locking mechanism, the respective first and second locking mechanisms being located respectively to engage laterally opposite sides of the door flap when the door flap

is in the closed position within the aperture, selectively to permit or prevent opening of the door flap in a respective opening direction. .

Preferably, the first and second locking mechanisms each have a respective reciprocable locking end part that, in the locking position, is extended into the aperture to be received within a respective corresponding first or second recess provided at a peripheral edge of the door flap.

Preferably, each recess has an open face through which a respective locking end part, when in the locking position, may be slidingly received into the recess when the door flap swings from an open position to a closed position, and a closed face against which the extended locking end part bears when the door flap is in the closed position, the two open faces of the first and second recesses being on respective opposite sides of the door flap.

Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, in which:-

Figure 1 is a perspective front view of a pet door in accordance with an embodiment of the present invention;

Figure 2 is a perspective rear view of the pet door of Figure 1;

Figure 3 is a perspective front view of the pet door of Figure 1 with the control unit separated from the frame of the pet door;

Figure 4 is a perspective view showing the assembly of the electric actuators and associated locking mechanisms in a rear frame member of the pet door of Figure 1;

Figure 5 is a perspective view of a locking mechanism shown in Figure 4;

Figure 6 is an exploded perspective view of the pet door of Figure 1; and

Figure 7 is a schematic illustration of the control unit and of the electrical connections between the control unit and the electric actuators of the locking mechanisms.

Referring to Figures 1 to 6, a pet door 2 in accordance with an embodiment of the present invention comprises a frame 4 surrounding a central aperture 6 in which a door flap 8 is pivotally mounted. In the illustrated embodiment, the door flap 8 is transparent, being composed of a transparent plastics material such as polymethylmethacrylate or polycarbonate. The door flap 8 is fitted to the frame 4 about two hinge parts 10 extending along a horizontal hinge axis about which the door flap 8 can pivot in either rotational direction. As is known in the art, the frame 4 may be provided with, fittings, for example mountings 12 for screws, to enable the pet door 2 to be securely mounted to a door or a wall of a building.

A U-shaped flap 14 is coaxially mounted with the door flap 8 about the hinge axis on the front side of the pet door 2. When the door flap 8 is opened in an inwards direction, the peripheral edge 16 of the door flap 8 bears against an adjacent periphery 18 of the U- shaped flap 14 so that the U-shaped flap 14 is pivotally opened together with the door flap 8. After the door flap 8 has been released, it falls back under gravity about the hinge axis so as to return to a vertical closed orientation. The additional weight of the U- shaped flap 14 also returning to a vertical orientation ensures that the door flap 8 safely returns to a vertical orientation and thus a closed position. Magnets (not shown) may be provided to generate an attractive magnetic force between the lower edge 20 of the door flap 8 and the frame 4 to assist the door flap 8 being held in a vertical closed orientation, for example to prevent inadvertent opening as a result of gusts of wind. A sealing gasket 22 of generally U-shaped plan is formed around the aperture 6 and in registry beneath the U-shaped flap 14 so as to inhibit drafts of air from entering the building through the aperture 6 when the door flap 8 is closed. When the door flap 8 is opened in the opposite rotational direction, away from the U-shaped flap 14, the U-shaped flap 14 stays static in a vertical orientation. When the door flap 8 is released, it again returns under the action of gravity to a vertical closed orientation.

The door flap 8 in accordance with the present invention is provided with two locking mechanisms 24, 26, each locking mechanism 24, 26 being adapted to lock the door flap 8 against opening from the closed position in a respective rotational direction. Thus one locking mechanism 24 prevents egress from the building, and the other locking mechanism 26 prevents ingress into the building,- through the pet door 2.

Accordingly, as shown in detail in Figures 4 to 6, first and second locking mechanisms 24, 26 are located within the frame 4. The frame 4 is formed from a front frame part 28 and a rear frame part 30 that are assembled together and define therebetween a central chamber 32 in which the first and second locking mechanisms 24, 26 are disposed. Each locking mechanism 24, 26 comprises a respective electrical actuator 34, 36 in the form of an electric rotary motor. The motor 34 _> 36 is typically an inexpensive rotary motor having a high number of revolutions per minute, typically about 10,000 revolutions per minute under low load conditions, and with low torque.

Each motor 34, 36 has a motor shaft 38 extending from a housing 40 of the motor 34, 36. An L-shaped arm 42 is fitted to the motor shaft 38 at a particular rotational orientation. The L-shaped arm 42 includes a radially outwardly extending part 44, with respect to the axis of rotation of the motor shaft 38, which is provided at the free end 46 thereof with a hole 48. A cam link 50 is provided with comprises an elongate element 52 with two outwardly extending lugs 54, 56 each at a respective opposed end 58, 60 thereof. A first lug 54 is received in the hole 48 of the L-shaped arm 42 and a second lug 56 is received in a hole 62 provided in a lock bolt 64. The lock bolt 64 is slidably received for reciprocal movement in a guideway 66 formed in the rear frame part 30 of the frame 4. The lock bolt 64 has a locking end part 68 which is located at an end 70 of the guideway 66 which terminates at the aperture 6 of the frame 4.

When the respective motor 34, 36 is electrically driven, the motor 34, 36 being drivable selectively in either a first rotational direction or an opposite second rotational direction, this causes corresponding rotational movement of the L-shaped arm 42, which in turn, by operation of the cam link 50, causes selective reciprocal movement of the lock bolt 64 in either a forwards direction towards the door flap 8, to a locked position, or a reverse

direction away from the door flap 8, to an unlocked position. In this way, each locking mechanism 24, 26 can be Selectively moved, by control of the respective electric motor 34, 36, between a locked configuration and an unlocked configuration.

In the locked position, the respective lock bolt 64 engages the door flap 8 within the aperture 6 and prevents the door flap 8 from moving in a respective rotational direction about the hinge axis.

Each locking end part 68, in the locked configuration, is received within a respective corresponding recess 72 provided generally along the lower edge 20 of the door flap 8. Each recess 72 comprises a semi-oval shaped cut-out 74 molded into the peripheral edge 16 of the door flap 8. Each cut-out 74 accordingly has, extending in a respective direction orthogonal to the plane of the door flap 8, an open face 76, through which a respective locking end part 68, when in the locking position, may be slidingly received into the cut-out 74 when the door flap 8 swings from the open position to the closed position, and a rounded closed face 78, comprised in the peripheral edge 16 of the door flap 8, against which the extended locking end part 68 bears when the door flap 8 is in the closed position. The closed face 78 therefore acts as a stop when the respective locking end part 68 is extended, the stop preventing further rotational movement of the door flap 8 in one rotational direction.

The two open faces 76 of the cut-outs 74 are on respective opposite sides 80, 82 of the door flap 8. Accordingly, one cut-out 74 together with the respective associated locking mechanism 24, prevents the door flap 8 from moving in one rotational direction when in the locked position and the other cut-out 74 together with the other associated locking mechanism 26 prevents the door flap 8 from moving in the other rotational direction when in the locked position.

The provision of these two cut-outs 74 in the peripheral edge 16 of the door flap 8 permits the lock bolts 64 to be disposed and operated in a common central plane which also includes the door flap 8 when in the closed position and the hinge axis. This also provides that the portions of the door flap 8 defining the respective cut-outs 74 can act as

a cover for the respective exposed locking end parts 68, thereby reducing the possibility of dirt or other debris fouling the locking mechanisms 24, 26. The locking mechanisms 24, 26 are disposed at opposed bottom corners 84, 86 of the frame 4 so as to provide a central portion 88 of the lower edge 20 of the door flap 8, and the corresponding adjacent part of the frame 4 defining the aperture 6, which is absent of any portions of the locking mechanisms 24, 26. This additionally tends to reduce the possibility of the locking mechanisms 24, 26 being fouled with dirt or debris as a result of movement of a pet through the pet door 2. By providing the two locking mechanisms 24, 26 in opposite lower corners 84, 86 of the frame 4 of the pet door 2, this enables the locking mechanisms 24,26 to be incorporated into the frame 4 without making the frame 4 excessively bulky or large in dimensions.

At an upper edge 90 of the frame 4, a control unit 92 for operating the locking mechanisms 24, 26 is provided. The control unit 92 comprises a housing 94 which is detachably held in a cavity 96 provided at the upper edge 90 of the frame 4. hi Figure 1 the control unit 92 is received within the cavity 96, and in Figure 3 the control unit 92 is shown removed from the cavity 96, in an exploded manner.

The cavity 96 is provided with a top opening 98 and a side opening 100 which merge together to form a common opening 102 in the frame 4. The control unit 92 is inserted into and removed from the frame 4 through the top opening 98. The side opening 100 permits a user manually to engage the control unit 92 so as to push it upwardly through the top opening 98. The side opening 100 also exposes a display 104 provided in the control unit 92. The control unit 92 is also provided with a plurality of manually operable controls 106, typically push buttons, for controlling the operation of the locking mechanisms 24, 26. The manually operable controls 106 are operable when the control unit 92 is detached from the frame 4. In the assembled configuration, the upper front face 108 of the frame 4 on either side of the side opening 100 conceals the manually operable controls 106. Accordingly, in the assembled configuration, children cannot press the manually operable controls 106 and thereby adjust the settings of the locking mechanisms 24, 26 of the pet door 2. If desired, a child proof clip mechanism is

provided in the frame 4 to securely clip the control unit 92 within the frame 4 so that it cannot be removed by a child.

Referring to Figure 7, the control unit 92 will be described in greater detail. The control unit 92 includes a programmable timer for selectively controlling the locking and unlocking of the locking mechanisms 24, 26 so as to provide a four way locking system for the pet door 2. The control unit 92 also includes the display 104 which is adapted to display time and also other information concerning the setting and operation of the control unit 92. Thus the display 104 includes a clock and icons showing the various settings. The control unit 92 also includes an electrical power source, in the form of batteries, for driving the electrical rotary motors 34, 36 as well as powering the programmable timer and display 104.

The electric rotary motor 34, 36 of each respective locking mechanism 24, 26 is independently driven by the control unit 92. The control unit 92 is provided with plural first electrical connectors 110, in the embodiment six electrical connectors 110. Two of the first electrical connectors 112 are for connecting to the first electric rotary motor 34 via respective complementary second connectors 114 and wiring 116 in the frame 4 and a further two of the first electrical connectors 118 are for electrical connection to the second electric rotary motor 36 via respective complementary second connectors 120 and wiring 122 in the frame 4. The remaining two first electrical connectors 124 are electrically connected to respective complementary second connectors 126 and wiring 128 in the frame 4 thereby forming a closed electrical loop 130 provided within the frame 4 which short circuits the two first electrical connectors 124 together.

The electrical connections between the detachable control unit 92 and the circuitry in the frame 4 connecting to the electric rotary motors 34, 36 therefore comprise complementary first and second electrical connectors which are provided respectively on the control unit 92, in the form of a detachable module, and on the frame 4 within the cavity 96. When the control unit 92 is received within the cavity 96, the first and second electrical connectors are electrically connected together. The electrical connectors are configured so as to permit repeated insertion and detachment of the control unit 92

relative to the frame 4 while maintaining good, electrical contact. Suitable electrical contacts will be known to those skilled in the art. -

The closed electrical loop 130 is provided for the electrical connection so that the control unit 92 is able to detect whether or not the control unit 92 has been inserted into the frame 4 and thereby electrically connected to the two electric rotary motors 34, 36 It is then possible, as described hereiribelow, for the control unit 92 immediately to drive the respective electric rotary motors 34, 36 to the desired rotational orientation, and thereby lock or unlock the respective locking mechanism 24, 26, as set by the programmable timer within the control unit for the particular time that the control unit is inserted into the frame 4 after programming of the control unit 92.

The programmable timer within the control unit 92 permits each electric rotary motor 34, 36 to be driven to a respective rotational orientation, corresponding to a locked or unlocked configuration for the respective locking mechanism 24,26, at various selected times during a 24 hour period. Plural time events may be programmed. The two locks can be independently controlled, so as to provide a four way lock which (1) locks the pet door in both directions; (2) locks the pet door in one direction; (3) locks the pet door in the opposite direction; or (4) does not lock the pet door in either direction. For example, the first electric rotary motor 34, which is configured to control the first locking mechanism 24 which prevents egress from the building, may be programmed to open at 07.00 hours and close the locking mechanism at 22.00 hours. The second electric rotary motor 36 may be programmed to control the second locking mechanism 26, which controls ingress into the building, so as to be unlocked at 08.00 hours and locked at 21.00 hours. In this way, the pet door can be programmed so as to control pet movements by night and by day.

The control unit 92 may be provided with a manual override to suspend the programmed event (a change of lock status) occurring and permit the locking mechanisms 24,26 to be set to an open configuration so that the pet door 2 can be opened in both directions indefinitely until the manual mode is cancelled. The pet door 2 may be optionally

provided with a manually operated four-way lock, as described hereinbefore with respect to the known pet doors, to control pet movements manually if desired.

The preferred embodiment of the present invention therefore provides an automatic four- way locking pet door. Two locks are provided that are independently programmable automatically to lock and unlock the door flap with respect to a respective opening direction at preselected times. This provides a much more versatile and user-friendly pet door than known four-way locking pet doors which are manually operated.

The provision of a control unit in the pet door that is removable from the frame provides the advantage that the operation of the pet door can be preset without requiring the user to crouch down to the height of the pet door. Also, the control unit automatically detects when it has been inserted back into the frame and thereby in electrical communication with the motors and associated circuitry in the frame, so that the motors can immediately be set automatically to their desired configuration for the actual time that the control unit has been reinserted. This provides the advantage that no remote control data or signal transmitter/ receiver system, for example using an infrared signal or an ultrasound signal which are conventionally used for remote control devices, is required. The avoidance of such a remote control data or signal transmitter/ receiver system, by the provision of a simple electrical detecting system between the control unit and the pet door, significantly reduces the production cost of the programmable electrically locking pet door. Also, since the programmable electrically locking pet door is unable to function without the control unit having been inserted into the cavity in the frame, because the control unit electrically powers the motors of the one or more locking mechanisms, there is little chance of the control unit being inadvertently lost.

Furthermore, by providing the batteries as well as the control electronics within the control unit, only the electrical actuators and the associated electrical wiring thereto from the electrical connectors need to be provided in the frame of the pet door. This reduces the complexity of the construction and assembly of the pet door, and reduces manufacturing costs.

In the illustrated embodiment the pet door is a four-way locking pet door that includes two locking mechanisms, each independently controlled to lock the door flap against movement in a respective opening direction. However, in a further embodiment only one locking mechanism is provided, and this is adapted either to lock the door flap against movement in one opening direction or to act as a bolt that locks the door flap against movement in both opening directions simultaneously.

Further modifications to the pet door of the present invention will be apparent to those skilled in the art, and are encompassed within the scope of the invention defined in the appended claims.