GB664770A - Improvements in hydraulic shock absorbers - Google Patents

Abstract

664,770. Hydraulic shock - absorbers. WOODHEAD - MONROE, Ltd., and ONIONS, J. W. May 17, 1950 [March 30, 1949], No. 8681/49. Class 108(iii) In a direct-acting hydraulic shock absorber, the valve of a valve-controlled auxiliary or byepass port within the hollow piston rod is adapted to be operated by an electro-magnet, which is carried by the piston rod and is adapted to be energized by connection to an electric circuit and remote operating switch. In the construction shown in Fig. 1 (Comp.), an inverted cup-shaped valve 50 controls flow between ports 58 and 59 in an extension 57 of the piston rod 53. The ports 58 open into the cylinder space above the piston (not shown), while the port 59 leads via a non- return valve 60 to the cylinder space below the piston. Within the piston rod 53 is a soft iron core 54 surrounded by a solenoid 54a the leads of which (not shown) extend through the end cap and securing ring of the shock absorber, and are connected with a suitable electrical circuit which includes a switch operable by the driver. The solenoid is retained by a bronze gland 56. The valve 50 may be downwardly loaded by a light spring (not shown). In operation the passages 59, 58 (when the solenoid 55 is energized to raise the valve 50 )provide a byepass flow on extension of the shock absorber additional to the normal damping action of a conventional valve assembly of the piston. In the construction shown in Fig. 1 (Prov.) a needle valve 13 controls flow between ports 14 and 15 leading between the upper and lower faces of the piston (not shown). The valve 13 is slidably mounted in a bronze bush 22 and has a soft iron head which co-operates with an electromagnet 12. The latter is supported by a flexible waxed ring 20 and a bronze sleeve 19. In the construction shown in Figs. 4, 5 flow between upper ,and lower faces of the piston is controlled by a rotary valve, Fig. 5 comprising a spindle 30 within the hollow piston rod 31 having an arcuate port 37 which cooperates with ports 36 opening above the piston. The port 37 is connected at 38 with a concentric port 39 which opens via a non-return ball valve, below the piston. The upper end of the spindle 30 carries a plurality of radially-disposed electromagnets 35 which function in the manner of a cogging motor. By the operation of a driver-controlled switch the spindle 30 may be rotated to connect selectively one or more of the ports 36 with the port 37.