GB686969A - Improvements in centrifugal servo-motors especially for braking systems - Google Patents

Abstract

686,969. Brake servomotors. PIGANEAU, G. P. Nov. 13, 1951 [March 5, 1951], No. 26555/51. Class 103 (i). A centrifugally-operated servomotor, particularly suitable for operating vehicle brakes, of the type comprising two axially-spaced plates 14 and 16 of which the plate 14 is fixed axially and rotatable by a pulley 6 from a running part of the vehicle, and the plate 16 is movable axially by the action of blocks 19 moved radially by centrifugal action in guides or ribs 17 on the inner side of plates 14 and 16, is characterized in that an adjustment stop such as the screw 34, is provided whereby the axial movement of plate 16 to operate hydraulic cylinders and pistons 30, 31 connected for instance to wheel brakes, is limited. By this means the power exerted by the servomotor device for a fixed driving speed may be varied to suit operational requirements, i.e. according to whether the vehicle is lightly or heavily loaded. As shown in Fig. 1, the plate 16 acting through a thrust bearing on a support disc 23 has a spindle 26 upon which the adjustment screw 34 acts, the spindle 26 being guided in the casing 28. Fig. 3 shows an arrangement whereby the adjustment screw 34 may be adjusted remotely by a hand wheel 43 geared to a pointer 47 that gives an indication on a graduated scale. The device is driven in known manner, as shown in Fig. 2, by tilting about a spindle 3 by a pedal 10 into engagement with a driving pulley 8. The driven pulley may be in two halves 6 expanded against springs 7 to provide a variable speed ratio according to the depth of engagement by driving pulley 8.