GB658193A - Improvements relating to combined fluid pressure operated jacks and shock absorbers - Google Patents

Abstract

658,193. Pneumatic single-stroke apparatus. ELECTRO-HYDRAULICS, Ltd., and PERDUE, J. June 11, 1948, No. 15859. [Class 8(ii)] [Also in Groups XXIX and XXXII] A combined jack and shock absorber comprises two tele scopic cylinders sliding one within the other, the inner cylinder forming a hollow piston rod of a piston work ing in the outer cylinder and the inner cylinder containing a piston and a hollow pistor rod, the outer cylinder form ing the jack and the inner cylinder forming the shock absorber or vice versa anc the jack including only a single piston. In Fig. 1 a piston 7 of a jack has a hollow piston rod 6 which en closes and forms the cylinder of an oleo-pneumatic shock absorber. The jack pistor can be moved to the right by fluid pressure supplied to a connection 3. To retract the jack fluid pressure may be supplied to the other side of the piston or as shown the space D may be used as an air space for the shock absorber. The spaces A and C are filled with oil and the space B and if desired also the space D are filled with air supplied at a connection 20. The shock absorber comprises a piston 8 carrying a closure member 17 having orifices 18, 19 therein one of which is preferably valved. During compression of the shock absorber the air is compressed by a free piston 16 operated by the oil in the spaces A, C. Internal locks could be fitted in the jack for the extended and the closed positions. In Fig. 2 a shock absorber piston 31 has a hollow piston rod 32 forming a jack cylinder and enclosing a jack piston 39. The shock absorber piston carries an extension 33 and piston 35. The extension slides in a diaphragm 34 fixed in a cylinder. Apertures 37, 38 are formed in the diaphragm and piston 35 some or all of which may be valved. Oil is contained in the spaces A, B, B<SP>1</SP> and air in the space C or spaces C, D or if desired the space E may form an additional air space of the shock absorber. The jack is extended by supplying fluid to a connection 42. Appropriate means may be provided to lock the jack in the ex tended and or closed position. It is.stated that the shock absorber could be of any other known type for example the liquid spring type. The jack may be closed by either (a) supply of fluid pressure near the base of part 32, Fig. 2 (b) letting the external load close the jack (c) inserting a spring in the space D or (d) connect space B as shown and let the common air spring close the jack.