Patent GB-458083-A (GB)
Title: Shock damper controls
IPC: B60G17/06
Filed: 1935-06-08
Abstract: 458,083. Controlling shock-absorbers. LESLIE, I. A., Highfield Lawn, Highfield Road. Derby. June 8, 1935, No. 16716. [Classes 108 (ii) and 108 (iii)] In a road vehicle suspension means, for I example mechanical or hydraulic, operated by front shock-absorbers or a part or parts moving therewith are provided which on a substantial displacement of the front wheels cause the rear shock-absorbers to be stiffened against rebound of the rear wheels. Fig. 2 shows a section of a valve device controlling flow of fluid from one compression chamber to another through a conduit in. a rear shockabsorber of the double-ended piston type, part of the conduit comprising a hole B and passage B<1>. Flow of fluid from hole B to passage B<1> raises by direct pressure a spring- pressed control valve B<2> seating in the hole B while flow in the opposite direction raises the valve by pressure on a sleeve B<4> slidable on the valve-stem and reacting against a diaphragm B<5> which is rigidly fixed on the stem and serves to damp oscillations of the valve by moving in an oil-filled chamber B<6>. The outer end of valve-spring B<3> bears against a cap C slidable in a chamber C<1> and normally engaging a shoulder C<2>. In order to increase the spring-pressure on the valve and therefore the resistance of the shockabsorber, the lower end of a lever D fixedly pivoted at D<1> is adapted to engage the cap while its upper end is connected by a link D<2> to the operating-arm of the front shockabsorber the link D<2> being slotted to engage a pin on the arm. Normal movements of the front wheels do not affect the link, but excessive movements cause the pin to engage the end of the slot and move the link, thus causing the lever D to depress the cap C momentarily and increase the resistance of the rear shock-absorber. In a modification, Fig. 3, the resistance of the rear shock-absorber is adapted to be maintained throughout its rebound movement by means of an hydraulic locking-member E against which the valvespring B<3> bears and which is formed with flats F, F<2> and is slidable in a chamber E<1> under the action of the lever D. The space above flat F<2> communicates through a hole F<3> with the shock absorber casing while the space below flat F communicates by a pipe F<1> with the rebound chamber of the shockabsorber so that after the member E has been moved by the lever D (as in the construction shown in Fig. 2) to compress the valve-spring B<3>, it is locked in position by the fluid-pressure in the space below flat F. In a further modification, Figs. 4, 5, the front shock-absorber A<1> is similar to one described in Specification 440,405 in which a rod G<2> is displaceable by a cam G<3> rigid with the operating arm A<3> 3 to increase the loading on the control valve G<4> in proportion to the extent of the rebound movement. -The hydraulic locking-member E, Fig. 5, on the rear shock-absorber A in this case carries a flange H between which and a fixed member E' a spring H<1> is arranged. On rebound movement of the front shockabsorber, when the fluid-pressure therein and in a conduit G leading to a chamber at the rear of the member E, reaches a predetermined value, the spring H<1> is overcome and the member E moved to increase the loading of the valve-spring B<3>. Leakage of liquid past the end of member E is prevented by packing J adapted to be forced outwardly by a piston J<1> under the pressure of fluid in the conduit G. The invention is also applicable to frictional shock-absorbers. The Provisional Specification describes also a construction in which excessive rebound movement of a front shock-absorber effects stiffening of a rear shock-absorber through electromagnetic means.