| 摘要 |
1,194,369. Vibratory screen. A. AHLSTROM OSAKEYHTIO, KARHULA BRUK. 24 Oct., 1967 [25 Oct., 1966], No. 48317/67. Heading B2H. A free vibratory screening apparatus, comprising a screen 3 forming part of a screen box supported 'by springs 6 and carrying a motor 1, is vibrated by means of at least two unbalanced weights which are drivingly connected to the motor 1. The centre of gravity of the unbalanced weights 2 and the centre of gravity of the motor 1 lie horizontally off centre with respect to a line passing through the centre of the screen. The mass centre of gravity G of the apparatus lies horizontally between the point of action of the vibratory force F produced by the unbalanced weights 2 and the line passing through the centre of the screen. The sum of the moments of the forces resulting from the springs 6 about the mass centre of gravity G is equal to the moment of the vibratory force F about the mass centre of gravity G, i.e. # q x b = F x a. The motor 1 and weights 2 are connected by members 8 to the screen box. A protective hood 4 has a side ventilation aperture 5 adjacent the motor 1. |
