Abstract: A pet fountain comprises an upper bowl, a base including a lower bowl. The upper bowl can be secured to the base so that it is elevated above the level of the base. The lower bowl is sufficiently large to accommodate the upper bowl when the upper bowl is not secured to the base. The internal space of the lower bowl has at least one span that is slightly greater than the longest measurement across the upper bowl.

Abstract: A system of locating a moveable RFID transceiver, in which the moveable transceiver is capable of sending and receiving TOF (Time of fight) signals, and also includes battery powered base stations suitable for outdoor use, and capable of sending and receiving TOF signals. The system measures the signals to derive time of flight information between the moveable transceiver and the base stations and using this data to calculate the position of the moveable transceiver. The position of the base stations may be fixed using TOF signals before attempting location of the moveable RFID transceiver. The base stations may be solar powered, and can work with a base network of only 2 base stations.

Abstract: A self-cleaning assembly comprising an enclosed casing 1 with a movable piston 31 and filters 32,33 therein. The preferred assembly has a casing 1 with a dirty water inlet 5, a first outlet 6 for clean filtered water and a second outlet 7 for the removal of sludge from the casing. The filter assembly is constructed and arranged to provide, in its normal operating mode, a liquid flow path through the filter 32,33 in a first direction between the dirty water inlet 5 and the clean water outlet 6 and, in a cleaning mode, to provide a liquid flow path in a second direction between the dirty water inlet 5 and the sludge outlet 7. In the cleaning mode, the movable member 31 compresses the filters 32,33 during the liquid flow in the second direction and contaminant is released therefrom for removal from the filter assembly via the second outlet 7. In an alternative embodiment, the sludge outlet 7 is omitted and sludge is removed from the casing via the outlet 6.

Abstract: An electro-magnetically controlled pet door having a door (1) pivotally mounted in a door aperture (17) of a frame (2) and an electrically controlled catch mechanism normally preventing opening of the door in at least one direction that is released when a magnet (30) carried by an animal approaching the door is sensed by two or more reed switches (23,24) on or in the frame mounted and connected electrically in parallel. The switches (23,24) are disposed in an array extending circumferentially of said door aperture and have normally open contacts and magnetic biasing means (26,27) are associated with the reed switches and positioned laterally thereof to increase their sensitivity.

Abstract: A filtration unit e.g. for ponds comprises a housing divided into a radiation chamber (18) with a water inlet (20) and a filtration chamber (19) with water outlets (21,22). A weir (23) in the partition wall (17) between the chambers controls the water level in the radiation chamber (18). One or more UV tubes (25,26) are mounted in the radiation chamber (18) above the water level therein controlled by the weir (23). Preferably the housing has a cover which is in two parts a first (33) of which extends over the radiation chamber (18) and is secured by screws or the like so that it cannot be removed inadvertently, and the second (34) of which extends over the filtration chamber (19) and is hinged to give ready access to the filtration chamber (19).

Abstract: A filtration unit for an aquarium tank comprises a biological filter chamber which is cyclically exposed to air and water without the use of conventional syphon means. Alongside the chamber is a U-tube arrangement one branch of which communicates at its upper end with the upper region of the chamber. Compressed air is continuously admitted to the chamber, e.g. by bubbling up beneath its open bottom end. When the water in chamber drops to the level of the bend of the U-tube air in the chamber expells remaining water from the U-tube and is able to evacuate chamber, enabling it to refill with water.

Abstract: A device for dispensing e.g. food to domestic animals comprises a dish divided into sector-shaped compartments over which a removable cover rotates. The cover has an opening which registers with the compartments in sequence. The cover is rotated by a clock spring at intervals timed by a timer mechanism in turn driven by an electric motor. Cams of the timer mechanism sequentially displace one end of a cam follower or rocker lever so that its other end disengages a first abutment rotatable with the cover, permitting the spring to rotate the cover until a next abutment is engaged. The abutments opposed to the direction of rotation of the cover by the spring extend progressively further from the axis of rotation of the cover, or in an alternative arrangement are stepped in the direction of its rotational axis. Similarly the cams of the timer mechanism extend progressively further from its axis of rotation or are stepped in the direction of this axis.

Abstract: In a dispensing device for automatically feeding fish a base 11 has mounted on its upper surface 14 a drive member 23 constantly rotated by a small, highly geared battery powered stepping motor controlled by a quartz controlled electronic circuit mounted within the base. A ring 15 of compartments freely rotatable on the surface 14 within location ribs 16 of the base has on its inner periphery 18 spaced ribs 26 one of which will be engaged by a pawl 25 or 25' of the drive member 23 during each revolution of the drive member, whereby the ring 15 is periodically arcuately displaced. The compartments of the ring 15 are open at top and bottom and in their path is an aperture 20 through the base. The compartments of the ring 15 are brought successively into alignment with the aperture 20 so that fish food located in the compartments is discharged by gravity through the aperture 20.

Abstract: A pet door comprises a frame defining an aperture in which a flap is pivotally suspended so as to close the aperture when it hangs vertically. A pet such as a cat can push the flap either way to pass through the aperture when entering or leaving a house. Entry is controlled by a solenoid-operated catch which is energized when a magnet carried on a cat's collar enters the common detection zone of an array of reed switches disposed at the distal end of an extension of the bottom of the frame in spaced relation to the plane of the aperture.