Direct-acting hydraulic pneumatic device

Claim 2

A cushioning arrangement for a railway car having an underframe, a sliding sill movably carried by said underframe and adapted to carry a coupler at at least one of its ends, and a hydraulic cushioning unit interposed between said sliding sill and said underframe, said cushioning arrangement comprising a first cylinder having a longitudinally extending axis, a second cylinder having a longitudinally extending axis offset from but parallel to the axis of said first cylinder, said second cylinder having a smaller diameter than said first cylinder and being disposed at the lower peripheRy of said first cylinder for forming a reservoir at least in part by the volume between the outer periphery of said second cylinder and the inner periphery of said first cylinder, the larger portion of said reservoir volume being formed above a plane containing the axis of said second cylinder, head means forming closures for the opposite ends of said cylinders, said cushioning unit having a stepped opening formed at one end thereof in alignment with said second cylinder, said stepped opening being comprised of a larger diameter portion extending through said one end of said cushioning unit and a smaller diameter portion with a shoulder defined therebetween, a bushing inserted into said opening and removable therefrom, said bushing having an enlarged head engaged with said shoulder and a reduced portion extending into the bore of said second cylinder, removable restraining means cooperable with said bushing head for retaining said bushing within said opening, said bushing being removable from within said opening upon removal of said removable restraining means, a piston rod slidably supported by said bushing and extending into said second cylinder, a piston affixed to said piston rod and supported for reciprocation in said second cylinder, means for reciprocating said piston and said cylinders relative to each other upon relative sliding movement between said sliding sill and said underframe, and means for restricting the flow of fluid from said second cylinder upon said relative movement between said piston and said second cylinder, at least a portion of the fluid so displaced being delivered to said reservoir, the fluid displaced into said reservoir leaving a volume in said reservoir which volume is filled with a high-pressure compressed gas for exerting a restoring force upon said hydraulic cushioning arrangement, the gas being in direct contact with the fluid in the reservoir.

Claim 3

A cushioning arrangement as set forth in claim 1 wherein the means for restricting the fluid flow from the second cylinder comprises a plurality of orifices formed in said second cylinder and extending from said second cylinder into the reservoir.

Claim 4

A cushioning arrangement as set forth in claim 2 wherein at least certain of the restricted orifices extend in a substantially vertical direction for return of entrained gases from the fluid in the second cylinder to the reservoir.

Claim 5

A cushioning arrangement as set forth in claim 3 further including dowel pin means for aligning the second cylinder with respect to the cylinder head means for fixing the vertical orientation of the orifices.

Claim 6

A cushioning arrangement as set forth in claim 1 further including means for charging the reservoir with a compressed gas comprising first fluid passage means extending through one of the cylinder heads from the reservoir, second fluid passage means extending through said one cylinder head from the atmosphere and adapted to receive a fitting, a third passage intersecting said first and said second passages and having at least a portion of its length threaded, and a closure plug received in said threaded portion of said third passage and adapted to prevent fluid flow between said first and said second passages when said closure means is in one position and for permitting flow between said first and said second passages when said closure means is in a second position.

Claim 7

A cushioning arrangement as set forth in claim 1 wherein the larger diameter portion of the opening in the one end of the cushioning unit is formed in the respective cylinder head, the smaller diameter portion of the opening comprising the bore of the second cylinder, the shoulder being defined by the respective end of the second cylinder.

Claim 8

A cushioning arrangement as set forth in claim 6 further including a second bushing fixed to the piston rod and received within the bore of the second cylinder for supporting said piston rod as the piston traverses the bore of the second cylinder.

Claim 9

A cushioning unit comprising A first cylinder defining an internal cylinder bore, a second cylinder having an outer periphery of smaller diameter than the cylinder bore of said first cylinder and having a cylinder bore, said second cylinder being received within said first cylinder with the axes of the cylinder bores of said cylinders being disposed in parallel but offset relationship, the axis of said second cylinder bore being offset downwardly from the axis of said first cylinder bore, a first cylinder head having a first pilot portion received within and supporting one end of said first cylinder and a second pilot portion received within and supporting said second cylinder, a second cylinder head having a pilot portion received within and supporting the other end of said first cylinder, said second cylinder head being formed with a first bore receiving and supporting the other end of said second cylinder, said second cylinder head being formed with a second bore concentric to said first bore and larger in diameter than said first bore a piston rod extending into said cylinder bore of said second cylinder through said bores of said second cylinder head, a first bushing extending into said second cylinder bore and slidably supporting said piston rod, said first bushing having an enlarged headed portion received within the second bore of said second cylinder head, a seal received within said second bore of said second cylinder head and juxtaposed to said headed portion of said first bushing, a snapring received within said second bore of said second cylinder head for affixing said seal and said bushing axially relative to said cushioning unit, a piston carried by said piston rod within said second cylinder bore, a second bushing supported upon said piston rod adjacent said piston and slidably engaging said second cylinder bore for supporting the inner end of said piston rod, piston ring means carried by said and slidably engaging said second cylinder bore, a plurality of axially spaced orifices extending through said second cylinder from its cylinder bore to its outer periphery and opening into a reservoir volume formed between the outer surface of said second cylinder and said first cylinder bore, said second cylinder bore and at least a portion of said reservoir being adapted to contain a fluid which fluid is forced through said orifices upon relative movement of said piston rod and said cylinders, the remaining volume of said reservoir being adapted to contain a high-pressure gas, a return passage formed in said first cylinder head and extending from said reservoir to said second cylinder bore, and check valve means in said return passage for permitting return flow of fluid from said reservoir to said second cylinder bore while precluding flow from said second cylinder bore to said reservoir.

Claim 10

A cushioning unit comprising A first cylinder defining an internal cylinder bore, a second cylinder having an outer periphery of smaller diameter than the cylinder bore of said first cylinder and having a cylinder bore, said second cylinder being received within said first cylinder with the axes of the cylinder bores of said cylinders being disposed in parallel but offset relationship, the axis of said second cylinder bore being offset downwardly from the axis of said first cylinder bore, a first cylinder head having a first pilot portion received within and supporting one end of said first cylinder and a second pilot portion received within and supporting said second cylinder, a second cylinder head having a pilot portion received within and supporting the other end of said first cylinder, said second cylinder head being formed with a first bore receiving and supporting the other end of said second cylinder, said second cylinder head being formed with a second bore concentric to said first bore and larger in diameter than said first bore a piston rod extending into said cylinder bore of said second cylinder through said bores of said second cylinder head, a first bushing extending into said second cylinder bore and slidably supporting said piston rod, said first bushing having an enlarged headed portion received within the second bore of said second cylinder head, a seal received within said second bore of said second cylinder head and juxtaposed to said headed portion of said first bushing, a snapring received within said second bore of said second cylinder head for affixing said seal and said bushing axially relative to said cushioning unit, a piston carried by said piston rod within said second cylinder bore, a second bushing supported upon said piston rod adjacent said piston and slidably engaging said second cylinder bore for supporting the inner end of said piston rod, piston ring means carried by said and slidably engaging said second cylinder bore, a plurality of axially spaced orifices extending through said second cylinder from its cylinder bore to its outer periphery and opening into a reservoir volume formed between the outer surface of said second cylinder and said first cylinder bore, said second cylinder bore and at least a portion of said reservoir being adapted to contain a fluid which fluid is forced through said orifices upon relative movement of said piston rod and said cylinders, the remaining volume of said reservoir being adapted to contain a high-pressure gas, a return passage formed in said first cylinder head and extending from said reservoir to said second cylinder bore, and check valve means in said return passage for permitting return flow of fluid from said reservoir to said second cylinder bore while precluding flow from said second cylinder bore to said reservoir.