Damper device for railway vehicle automatic couplings

Claim 1

A damper device for an automatic coupling Of a railway vehicle comprising a cylinder for containing hydraulic liquid, a piston slidably mounted in said cylinder and dividing said cylinder into a first chamber and a second chamber, said piston having a passage therethrough interconnecting said first and second chambers, a flow regulating element fixed in said first chamber and extending into said passage, said piston having a stem extending axially outwardly of said cylinder, a terminal force receiving plate secured to the end of said stem and resilient means disposed intermediate said terminal force receiving plate and said cylinder, and means for compensating changes in the combined volume of said first and second chambers upon movement of the piston and stem within said cylinder, said compensating means comprising wall means defining an annular auxiliary chamber surrounding said cylinder for containing hydraulic fluid and a gas, first and second conduit means extending between said auxiliary chamber and said first chamber, first valve means associated with said first conduit for permitting the unrestricted flow of hydraulic fluid from said auxiliary chamber to said first chamber but totally preventing the flow from said first chamber to said auxiliary chamber and a second valve means associated with said second conduit having calibrated spring means which permits restricted flow of hydraulic fluid from said first chamber to said auxiliary chamber but prevents flow from said auxiliary chamber to said first chamber.