Abstract: An air temperature control device for the air intake of an internal combustion engine comprises a thermo-responsive actuator which is, in use, disposed to respond to the air temperature in said intake system, a first valve means operably connected to the actuator for progressive movement in a first chamber provided with air inlet and/or outlet ports between two positions, in the first of which positions a first bleed passage from the chamber is closed and in the second of which positions said first bleed passage is open permitting the passage of air to or from said ports from a second chamber provided with an air inlet which is connected in use to a vacuum motor operable to adjust the relative proportions of ambient and pre-heated air admitted to the intake system, and a second valve means to close said bleed passage and also operable to close a second bleed passage between said second chamber and a third chamber having a port which is connected (in use) to a vacuum source constituted by the air intake manifo

Abstract: A self-cleansing air cleaner comprising an air blast nozzle which is driven at constant speed through a path including at least two filter sections includes means responsive to each air blast to temporarily halt the nozzle during at least part of the duration of the blast, and to thereafter re-synchronize the nozzle movement with that of the constant speed drive.

Abstract: A rubber or elastomer gravity dump valve for an air cleaner is provided with an internal bracing strut to control the compliance of the valve discharge lips. The strut extends across the valve at or adjacent to the point of lip initiation.