Abstract: A dispenser device (10) for dispensing liquid detergent concentrate or cleaning agent into a washing zone of a washing appliance during a phase of a washing cycle. The washing appliance has a water pump (6) to provide the normal functions associated with washing cycles. Water pressure from the pump is utilised to squeeze or eject a predetermined quantity of concentrate from a container (28) into the washing zone at a desired phase of the washing process. In one adaptation, a container for the concentrate is in the form of a flexible bag (28) including an outlet nozzle (32) sealed until first placed in a receptacle (11) for use. In use, the nozzle (32) protrudes through an opening in a closure (12) of the receptacle into the washing zone. Via a second opening in the receptacle a small volume of water under pressure from the pump is directed under the timed control of a valve (26) at the required phase of the washing cycle into the closed receptacle.

Abstract: A heat exchange assembly having a primary heat exchange element (20) intercommunicating with secondary heat exchange element (24) both housed in an enclosure (12). Hot combustion products from burner (28) are forced by fan (19) through the primary and secondary heat exchange elements in turn to an exhaust (31) whilst air to be heated is induced by fan (14) through enclosure (12). The flow direction of hot combustion products and their temperature drop along their flow path when considered with the flow direction of air being heated and delivered from outlet (16) of enclosure (12), ensures heat exchange characterized predominantly as counter-current and hence optimally efficient in consideration of the compact dimensions of the enclosure (12).

Abstract: A solar energy conversion apparatus which includes a reflective parabolic trough which tracks the sun the control means therefor being such that the trough rotates about a north-south axis alternately to east and west extreme positions until the driving motor is disabled by equal irradiation of a pair of phototransistors. The phototransistors are aligned relative to the axis of the trough such that they are equally irradiated when the sun's rays are concentrated on a heat transfer tube extending along the axis of the trough. The apparatus has a flexible disc drive member to mechanically couple the trough to the drive motor. The heat transfer conduit is of relatively small capacity and a two-phase flow therein is utilized so as to conserve energy.

Abstract: A solar energy conversion apparatus which includes a reflective parabolic trough which tracks the sun the control means therefor being such that the trough rotates about a north-south axis alternately to east and west extreme positions until the driving motor is disabled by equal irradiation of a pair of phototransistors. The phototransistors are aligned relative to the axis of the trough such that they are equally irradiated when the sun's rays are concentrated on a heat transfer tube extending along the axis of the trough. The apparatus has a flexible disc drive member to mechanically couple the trough to the drive motor. The heat transfer conduit is of relatively small capacity and a two-phase flow therein is utilized so as to conserve energy.

Abstract: An instantaneous hot water heater having a coiled heat exchanger (4) through which water to be heated passes. A fuel supply assembly (22) is provided for supplying air and gas to the interior of the exchanger for combustion in such a way that combustion occurs as a series of rapidly occuring pulses at a rate of typically 50 to 100 ignitions per second. There is considerable turbulence in the combustion products whereby good heat exchange takes place enabling very efficient operation.

Abstract: This specification discloses a reflective trough structure suitable for use in solar energy collecting apparatus. The trough structure comprises an initially flat sheet of aluminium which is resiliently deformed into engagement with concave ribs so that the sheet assumes a parabolic configuration without any need to work the surface of the aluminium sheet which would tend to degrade the reflective properties of the sheet.

Abstract: The invention provides solar conversion apparatus comprising concentrating means for concentrating solar energy onto at least one surface of a heat transfer conduit, tracking means for causing the concentrating means to track the sun, the tracking means including radiation sensitive elements which are operable on differential thermal expansion thereof to generate tracking control signals and an electric motor for moving said concentrating means, said motor being responsive to said control signals, tracking movement thus being initiated by thermal radiation but is arrested by optical radiation which is of short response time.

Abstract: A cover for a swimming pool is disclosed comprising first and second layers of plastics material joined together at join zones, to define a plurality of spaces therebetween the spaces being inflated or inflatable, whereby the cover floats when placed on the surface of a pool with the second layer lowermost, at least the second layer being distended away from the join zones and having downwardly projecting crests which in use contact the surface of the pool and the join zones are located above the surface of the pool and wherein drainage holes are formed through the first and second layers at the join zones to provide fluid communication paths from the upper side of the cover to the air space defined between adjacent crests in the second layer and the surface of the pool whereby rainwater drains effectively into the air spaces so defined and then into the pool.

Abstract: Solar tracking apparatus is disclosed which utilizes received solar energy to effect tracking movements, the apparatus comprising focussing means, mounting means mounting the focussing means for tracking movements of the sun, drive means including heat expansible members movable with the focussing means, the heat expansible members being disposed relative to the focussing means so as to receive different amounts of solar radiation from the focussing means when the focussing means is misaligned with the sun so as to produce a differential expansion therein, the drive means being operable on differential expansion of said heat expansible members to cause movement of the focussing means in a direction towards realignment with the sun.