GB664972A - Improvements relating to liquid spring shock absorbers - Google Patents

Abstract

664,972. Liquid spring devices. DOWTY EQUIPMENT, Ltd., and CUSSONS, R. C. Oct. 27, 1950 [July 28, 1949], No. 19892/49. Class 108(iii) In a liquidspring type shock absorber, which may be of the kind described in Specifications 560,047 and 560,048, a part of the liquidconfining structure of a single liquidfilled chamber is engaged by the plunger at a predetermined stage during a compression stroke to move the part relatively to the remainder of the liquidconfining structure whereby to increase the rate of liquid compression in the chamber during the remainder of the stroke. In the construction shown in Fig. 1, a hollow plunger 11 is slidable relative to a liquid-filled cylinder 14 which is rigid with an inner cylinder 15 having a communicating port 16 with the main cylinder 14. Glands 12, 13 of the type described in Specification 539,966, [Group XXXVI], retain liquid in the cylinder 14 and an axiallydisplaceable gland 17 retains liquid in the cylinder 15. The gland 17 has a stem 19 which is engageable with a boss 22 on the plunger, at a predetermined point in the compression stroke. In the construction described in Fig. 2 a sleeve 24 is engageable by the plunger 23 after a predetermined degree of its travel, the inner part of the sleeve then entering the cylinder 26 and thus increasing the rate of compression of the liquid therein. Glands 25, 27 are provided between the sleeve, and the cylinder and plunger. In a further construction, Fig. 3 (not shown), each end of a liquidfilled cylinder is glanded for the reception of a respective plunger. One plunger is of lesser diameter than the other and a shoulder on the former plunger engages the respective cylinder-end after a predetermind degree of plunger travel. Further compression of the shock absorber thus results in the cylinder being penetrated by the larger-diameter plunger with consequent increased rate of liquid compression. The plungers in each construction may be provided with heads having damping orifices. According to the Provisional Specification, the plunger of a construction similar to that shown in Fig. 2, may be hollow. A rod extends from the cylinder into the hollow plunger and carries a head slidable therein. The invention is particularly applicable to aircraft designed for deck take-off and for aircraft requiring increased wing incidence for take off.