GB475815A - Improvements in or relating to the actuation of hoods and opening tops of motor road vehicles - Google Patents

Abstract

475,815. Vehicle hoods and opening- tops. HAMILTON MOTORS (LONDON), Ltd., and THEED, W. D. L. May 25, 1936, No. 14794. [Class 108 (i)] In apparatus for actuating the hood or opening-top by means of one or more suctionoperated pneumatic servomotors means are provided whereby during the initial opening movement of the hood the force applied is comparatively great to cause a rapid initial opening movement which is checked by the servomotors during the final closing movement. The main hoop stick E at each side is provided with a quadrant E<1> gearing with a gear C<2> mounted on a cross shaft D. At one or both sides the gears C<2> are engaged by a rack C<1> on a piston rod C secured to a piston B mounted in a cylinder A. The ends of the cylinder A communicate, througt pipes F, G and expansion chambers F<1>, G<1>, with a valve casing H having ports H<1> ... H<4> therein, the port H<3> communicating through pipe K with the induction pipe K<1> of the engine. A valve L operable by a handle L<3> is provided and is adapted to put the ports H<1> and H<4> and H<2> and H3 respectively into communication as shown or the ports H<1> and H<3> and H<2> and H<4> respectively or to close all the ports. The port H<4> is provided with a needle valve J whereby the communication with the atmosphere is restricted. In operation and for lowering the hood the valve L is rocked to place ports H<1> and H<3> and H<2> and H<4> in communication respectively whereupon the vacuum above the piston B causes the latter to rise rapidly until the movement is damped by the depression caused on the other side of the piston after which movement takes place at a rate determined by admission of atmospheric pressure through the restricted port H<4>.