| 摘要 |
829,891. Hydraulic shock absorbers. CANADAIR Ltd. Nov. 20, 1957 [June 25, 1957], No. 36166/57. Class 108(3) [Also in Groups XXXI and XXXIII] An articulated vehicle (see Group XXXI) comprises two or more units 5, 6 connected by a ball joint 7 about which relative roll and pitch is controlled by a system 8 of shock absorbers 24 connected to the units in V formation by ball joints at 27 and 28. Each shock absorber 24 is a cylinder 29 containing hydraulic fluid, closed at its open ends by blocks 33 and moving over a piston head 32 on a rod 31. The head 32 has two transverse ports 40 and 41 'and two check valves 42 and 43 that control the flow of fluid between the cylinder bore one either side of the piston head 32 and a control chamber 34 bored axially in the rod 31. The chamber 34 moves over a control needle 35 in the form of a double piston 35a and 35b connected by a tapered mid-section 36, 37, 38. When the vehicle is on level ground the piston 32 is at the centre of its travel and is central with respect to the control needle 35. Movement of the piston in either direction causes a flow of fluid from one side of the head 32 to the other through the ports and valves 40 to 43. At the same time the increasing diameter, due to taper, of the control needle where it passes under the ports 40 and 41 causes a rapid build up of resistance to the motion, which is finally checked completely when either of the piston portions 35a or 35b seals the ports. |
