Abstract: A swimming pool cleaner has a body which defines a liquid inlet and an outlet which is connected via a hose to a source of suction. A throat between the inlet and the outlet defines a region of reduced cross-sectional area, causing a zone of low pressure as liquid flows through the throat. A valve element in the form of a cylindrical shuttle is located in a bore which intersects the throat, and which can move into the throat to block it intermittently. An auxiliary suction passage connects the rear of the bore to the outlet, so that suction is applied to both ends of the shuttle, causing it to reciprocate in the bore, periodically obstructing the flow of liquid through the throat. This causes the cleaner to move across the submerged surface. The design of the cleaner makes it resistant to jamming due to objects being trapped between the valve element and the throat.

Abstract: This invention relates to a pool skimmer which is adapted to remove floating fractions, such as floating debris, from the surface of water. The pool surface skimmer of the invention comprises a housing within which a strainer separates a high level inlet from a low level outlet. The inlet is adapted to float below the surface of the water by means of two or more flotation chambers defining, between them, one or more intake ports each closable by means of a gate which is adapted to allow the ingress of water from the surface of the pool upon withdrawal of water from the outlet of the housing. The strainer is complemental, in outline shape, to the inlet cavity at the water surface and the gates are located closely adjacent the housing wall defining the inlet cavity of the apparatus. It is therefore possible, by removal of the strainer, to clear the entire water surface of the inlet cavity for removal or reclamation of the floating fraction separated in this manner.

Abstract: This invention relates to a motor vehicle immobilizing device which is adapted to disable the drive train of the motor vehicle under the control of known remotely controllable locking means adapted releasably to lock an actuator member constituted by a transmission gear selector lever (74) in a predetermined position when the lever is moved to that position. the predetermined position of the lever (74) coincides with the position of a gear selection which disables the vehicle drive train. This could be achieved by disengaging the gear box, that is by selecting the "neutral" position of the transmission or, in automatic gear boxes, by selecting the "park" position of the transmission, or in all types of gearboxes, by selecting the "reverse" position of the transmission. The object in each case is essentially to make it difficult, if not impossible, to drive the vehicle away in any normal manner.