GB1514913A - Vibrators - Google Patents

Abstract

1514913 Fluid-operated vibrator E FENTON 1 Sept 1975 [30 May 1974 13 June 1974] 23923/74 and 26186/74 Heading F1M In a piston-cylinder fluid vibrator of the type where the piston 42 co-operates with inlet and exhaust ports 47, 49 in the cylinder 43 to supply pressurized fluid alternately to each of the two cylinder chambers defined by the piston to cause the piston to oscillate, the exhaust ports 49 are in communication with an expansion chamber comprising an axially extending cylindrical bore 30 in the wall of the vibrator, and this chamber communicates with a fluid outlet 34 extending radially from the wall. The expansion chamber enables the pressure differential between the cylinder chambers to be more rapidly established. The inlet ports 47 are in communication with a reservoir chamber 46 supplied from a fluid source along pipe 48. The piston 42 has two circumferential grooves 44 which communicate via axial grooves 45 with the cylinder chambers, and are brought into communication with the inlet ports 47 as the piston oscillates. In the position shown the piston closes off both inlet and both outlet ports. If the piston is moving to the left, fluid is supplied to the left hand chamber and exhausted from the right hand chamber to the expansion chamber 30 and outlet pipe 34. The piston therefore rebounds to the right causing fluid to be supplied to the right hand chamber and exhausted from the left hand chamber. In the embodiment of Fig. 2 (not shown), there is no reservoir chamber supplying the inlet ports and the fluid supply pipe (14) communicates directly with a single circumferential groove (13) in the piston. This groove communicates (depending on piston position) with one of the two inlet ports, which communicate with the cylinder chambers (19, 20) via axial passages (15) in the cylinder wall. The exhaust ports (17) communicate with an expansion chamber (16). These vibrators provide a rapid deceleration of the piston at the ends of its stroke, resulting in a more rounded (approximately sinusoidal) waveform for the vibration than is usual. The vibrator is used to vibrate a bowl feeder.