GB1298796A - Pneumatic vibrator - Google Patents

Abstract

1298796 Vibrators INSTITUT GORNOGO DELA SIBIRSKOGO OTDELENIA AKADEMII NAUK SSSR 16 Aug 1971 38386/71 Heading F2X [Also in Division B1] A pneumatic vibrator comprises a housing 1 in the form of a closed cylinder, an impact member 2 mounted for reciprocation within the housing, two impact-receiving members in the form of discs 19, 20 for imparting longitudinal and transverse vibrations to the housing, each mounted within the housing with radial and axial clearances by means of resilient suspension members 23, 24 secured to the end walls 21, 22 of the housing, and striking means in the form of projections 17, 18 disposed eccentrically on opposite end faces of the impact member 2 for delivering impacts on portions of the discs 19, 20 remote from the central axes of these discs. Compressed air is fed from a hose 30 to a supply passage 25 formed in the wall of the housing 1, from which it passes via an opening 27 in the housing and a system of axial passages 3 and 4, radial passages 5 and 6, tangential passages (only the outlets 15 and 16 of which are shown) and annular grooves 9, 10, 11 and 12 in the impact member 2 to one or other of the working spaces 13 and 14, the spent air being exhausted through openings 28 and 29 in the housing to an outlet passage 26, formed in the housing wall in a similar manner to the supply passage 25, and a hose 31 disposed around and spaced from the hose 30. The compressed air issuing from the outlets 15 and 16 of the tangential passages effects rotation of the impact member 2 about its central axis, whereby circular transverse vibrations of the housing 1 are obtained. In an alternative embodiment (Fig. 11, not shown), the impact member is reciprocably mounted on a hollow shaft which is divided internally by a profiled longitudinal partition to define supply and exhaust conduits which take the place of the passages in the housing wall of the first embodiment, resulting in a reduction in the weightof the vibrator and an increase in the amplitude of the transverse vibrations. In order to create a variable agitating force, 'to 'attain a low frequency of the transverse vibrations and to increase their amplitude, the centre of gravity of the impact member may be displaced relative to its axis of rotation, as by providing a hollow cavity in the impact member to one side of its axis of rotation. The amplitude may also be increased by mounting a one-way valve (Fig. 14, not shown) in the body of the impact member, which valve is adapted to open upon the pressure in one working space rising above the rated supply pressure. A protective cylinder may be mounted interiorly of the housing with resilient means, e.g. a corrugated leaf-spring, interposedbetween the cylinder and the housing so as to reduce the wear of the housing wall. In a further embodiment (Figs. 20 and 21, not shown) the impact-receiving discs and the end walls of the housing have conically tapering peripheral surfaces which engage one another at the time of impact, the longitudinal components of the impacts thus being partially used for imparting transverse vibrations to the housing. These impact-receiving discs might be connected to the end walls by spherical bearing means. In a still further embodiment (Fig. 19, not shown), the housing is divided into two chambers by an intermediate transverse wall, there being an impact member reciprocably mounted in each chamber and the intermediate wall supporting discs co-operating with the impact members for imparting vibrations to the housing.