Patent GB-951094-A (GB)
Title: Method and apparatus for protecting railway vehicle loads
Inventor: PETERSON WILLIAM HARTIN
IPC: B61D45/00
Filed: 1960-09-26
Abstract: 951,094. Railway vehicle undercarriages; combined buffer and draw gear. PULLMAN Inc. Sept. 26, 1960, No. 33010/60. Headings B7L and B7T. [Also in Division F2] A railway freight carrying vehicle comprises a centre sill 51, Fig. 4, with fixed end bolsters 54 connected in known manner to bogie tracks, the ends of the bolsters being provided with rollers 62 engaging in channel side sills 52 of a load-carrying body underframe 50, the sills 52 being connected together by end cross-bearers 60 and centre cross-bearers 61, all of which are provided with openings to allow passage therethrough of the centre sill 51. The invention is characterized by a shock absorber 80, Fig. 7, disposed within the sill 51 and having followers 81, 82 engaged between pairs of lugs 83 secured to the centre sill and stop members 84 on the centre cross-bearers 61, each stop member being aligned with an associated pair of lugs and the shock absorber having a travel range of 18 1/2 inches to 40 inches. Normal buffing and draft forces are sustained by conventional coupler gears at the ends of the centre sill but collision impacts cause relative movement between the centre sill and the load-carrying underframe 50 to compress the shock absorber 80 and thus prevent damage to lading carried by the vehicle. The shock absorber is returned to its neutral position by springs. In another embodiment described with reference to Figs. 10 to 12 (not shown), the shock absorber is engaged between a sliding draft and buffing column and the vehicle underframe. When applied to a railway vehicle for transporting a road vehicle semi-trailer the shock absorber is engaged between the railway vehicle underframe and an elevated stand engageable with the front end of the semi-trailer as described with reference to Figs. 35 to 39 (not shown). The railway vehicle in this case is also provided with stanchions carrying adjustable rollers to engage the semi-trailer body to accommodate the sliding movement between the stand and the underframe. Referring to Figs. 13, 14 and 15, an hydraulic shock absorber comprises a cylinder 131 having a closure member 136 and a tubular piston-rod 133 having at one end a piston head 132 slidable in the cylinder. At the other end the piston-rod has a closure member 137. The piston rod 133 is slidable through a guide member 147 secured by snap rings 145, 146 in the cylinder and provided with apertures 167. The rod 133 also slides over a guide member 139 provided with apertures 165 and secured on a tapered metering pin 137a secured to the closure member 136. The pin 137 passes through an orifice 160 in the piston head 132, the movement of which, to the left in Fig. 15, is limited by a snap ring 144. Adjacent the piston head the piston rod is provided with apertures 164. Secured to the piston rod and the guide member 147 is a flexible impervious invaginating tubular member 134 and between the closure members 136 and 137 are springs 135 for urging the members against the lugs on the relatively movable parts of the vehicle. As the piston head is urged into the cylinder during heavy impacts, hydraulic liquid which fills the cylinder, tubular piston rod and the invaginating member, is passed from the right-hand side 162 of the cylinder through the orifice 160, the effective area of which continually decreases as the cross-section of the pin 137a gradually increases, into the rod 133, radially outwardly through the openings 164 into a turbulence chamber 166. The liquid displaced from the interior 138 of the piston rod passes through the openings 165, 164 and 167 into the flexible member 134 which stretches about 100% when inflated, the parts adopting the positions shown in Fig. 14. The springs 135 thereafter return the parts to the positions shown in Fig. 13, whereby the loadcarrying body is returned to its normal position on the vehicle underframe. In another embodiment of shock absorber described with reference to Figs. 31 to 33 (not shown), a friction tube secured to the vehicle underframe centre sill passes through pairs of hinged clamping members and the ends of the clamps remote from the hinged ends are connected to two parallel channel beams in turn connected to an hydraulic piston and cylinder. The ends of the friction tube are secured to the ends of a piston rod passing through another hydraulic cylinder parallel to the beams and provided with a central piston. This hydraulic cylinder increases in cross-section from each end towards the centre and the ends are connected by pipes to a ball-valve in turn connected to the firstmentioned cylinder. As the friction tube is moved under an impact, the central piston moves in one direction in the cylinder parallel to the beams and forces liquid from one end of that cylinder to one pipe and thus the cylinder and piston connected to the beams to thus clamp the friction tube with gradually increasing force. Liquid is prevented from returning to the other end of the cylinder parallel to the beams, by the ball valve. In a further embodiment described with reference to Figs. 40 and 41 (not shown), the viscosity of the oil circuit in a hydraulic shock absorber is variable by a magnetic device acting on pulverulent magnetizable particles in the oil, the magnetic device being controlled by the relative movements between the load-carrying member and the vehicle underframe. A still further embodiment of shock absorber is described with reference to Fig. 42 (not shown) and comprises friction shoes in the form of wedges carried by an impact receiving rod, the wedges being engageable with the interior of a cylinder when the wedges engage a central slidable weight on the rod. Specification 897,293 is referred to.