Abstract: A fluid seal for use between two relatively rotatable members and including a body section to be secured to one member or its support, and a circular lip projecting from the body for sealing engagement about or around a surface of the other member. The lip is defined by two angularly arranged surfaces which meet at a common edge to form a sealing edge of the lip, and a pumping configuration is provided on one of those surfaces. A feature of the invention is the provision of discontinuities around the lip edge so that relatively small discrete passages provide a communication between the two sides of the lip whereby fluid can be returned through the seal under the influence of the pumping configuration. The discontinuities can be formed by projections on the lip edge which are depressed to create the communication passages through distortion of the lip, or they may be recesses or gaps preformed in the lip edge.

Abstract: A fuel injection control apparatus of the kind in which an auxiliary throttle air flow monitor responds to flow of air through an air passage, and by that response influences switching means for the injectors such that the injector on-time is determined by the flow monitor. It is a feature of the apparatus that a control element is arranged to intrude into the air passage to form a restriction to flow of air and thereby influence the flow monitor position, and to also provide a stop which is engageable by the flow monitor to determine a minimum flow position of that monitor. The control element position is regulated by a device which responds to changes in engine temperature so that the control element intrusion is at a maximum under cold conditions and is at a minimum or is non-existent at normal operating temperature of the engine.

Abstract: Traversing mechanism for use in any type of machine in which part of the machine is required to reciprocate between two predetermined limits of travel. The mechanism includes a carriage which is attachable to that machine part, and an endless belt which, in operation, is continuously driven in one direction and has two parallel runs located on opposite sides of the carriage. A rotatable coupling wheel is mounted on the carriage and has an odd number of radially projecting lobes arranged around its periphery so that in one rotational position of the wheel one lobe engages one run of the belt, and in another rotational position of the wheel another lobe engages the other run of the belt. The arrangement is such that in each rotational position of the wheel there is only one lobe in full engagement with the belt.