Hydraulic piston-cylinder device having means for permitting limited reciprocating motion

Claim 2

In combination: a pair of pivotally interconnected parts movable angularly with respect to each other and having an atrest position, a hydraulic piston-cylinder device connected to and between said parts for moving them relative to each other and comprising a cylinder having a bore wherein a piston is slidably movable, said piston and cylinder having at least one at-rest position relative to each other corresponding to the at-rest position of said parts; hydraulic means including a pump for supplying hydraulic fluid to said bore on either side of said piston to effect relative movement between said pair of parts, said hydraulic means further comprising a reservoir; and means for permitting limited reciprocating movement between said piston and cylinder in response to relative movement of said parts about their at-rest position, said means comprising passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said zone being of a length greater than the axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connected to said reservoir.

Claim 3

A combination according to claim 1 wherein said passage means comprises a pair of interconnected ports longitudinally spaced apart from each other with respect to said cylinder and with the spacing between said ports defining the length of said zone.

Claim 4

A combination according to claim 2 wherein said ports are provided in said cylinder and communicate with said cylinder bore and are interconnected by a passage located externally of said cylinder bore.

Claim 5

A combination according to claim 2 wherein each of said ports takes the form of at least one space between the wall of said cylinder bore and said piston and are interconnected by a passage in the form of a space between the wall of said cylinder bore and said piston.

Claim 6

A combination according to claim 4 wherein said passage takes the form of at least one longitudinal groove formed in the bore of said cylinder.

Claim 7

A combination according to claim 4 wherein said passage takes the form of annular widening formed in the bore of said cylinder.

Claim 8

A combination according to claim 4 wherein said passage takes the form of at least one helical groove formed in the bore of said cylinder.

Claim 9

A combination according to claim 2 including a piston rod having a pair of spaced apart stops, said piston being slidably movable on said rod between said stops; and wherein each of said ports is located adjacent a stop and takes the form of a space between said piston rod and said piston.

Claim 10

A combination according to claim 8 wherein said ports are interconnected by a passage formed in the surface of said piston rod.

Claim 11

A combination according to claim 9 wherein said passage takes the form of at least one longitudinal groove.

Claim 12

A combination according to claim 9 wherein said passage takes the form of at least one helical groove.

Claim 13

In combination: a pair of pivotally interconnected parts movable angularly with respect to each other and having an at-rest position, said parts being adapted for limited relative movement from said at-rest position, a hydraulic double-acting piston-cylinder device connected to and between said parts for moving them relative to each other and comprising a cylinder having a bore wherein a piston is slidably movable, said piston and cylinder having at least one at-rest position relative to each other corresponding to the at-rest position of said parts; hydraulic means including a pump for supplying hydraulic fluid to said bore oN either side of said piston to effect relative movement between said pair of parts and normally preventing relative movement between said piston and cylinder from said at-rest position in response to movement of said parts, said hydraulic means further comprising a reservoir; and means for permitting limited reciprocating movement between said piston and cylinder in response to limited relative movement of said parts about their at-rest position, said means comprising passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said passage means comprising a pair of interconnected ports longitudinally spaced apart from each other with respect to said cylinder and with the spacing between said ports defining the length of said zone, said length being greater than axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connected to said reservoir.

Claim 14

In combination: a pair of pivotally interconnected parts movable angularly with respect to each other and having an at-rest position, said parts being adapted for limited relative movement from said at-rest position, a hydraulic double-acting piston-cylinder device connected to and between said parts for moving them relative to each other and comprising a cylinder having a bore wherein a piston is slidably movable, said piston and cylinder having at least one at-rest position relative to each other corresponding to the at-rest position of said parts; hydraulic means including a pump for supplying hydraulic fluid to said bore oN either side of said piston to effect relative movement between said pair of parts and normally preventing relative movement between said piston and cylinder from said at-rest position in response to movement of said parts, said hydraulic means further comprising a reservoir; and means for permitting limited reciprocating movement between said piston and cylinder in response to limited relative movement of said parts about their at-rest position, said means comprising passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said passage means comprising a pair of interconnected ports longitudinally spaced apart from each other with respect to said cylinder and with the spacing between said ports defining the length of said zone, said length being greater than axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connected to said reservoir.

Claim 15

In a hydraulic piston-cylinder device for use with hydraulic means including a pump and a reservoir: a cylinder having a bore and a piston slidably mounted in said bore, said cylinder having fluid ports on either side of said piston, said piston having at least one at-rest position with respect to said cylinder; and means for permitting limited relative reciprocating movement between said piston and said cylinder about said at-rest position, said means comprising hydraulic fluid passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said zone being of a length greater than the axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connectable to said reservoir.

Claim 16

In a hydraulic piston-cylinder device for use with hydraulic means including a pump and a reservoir: a cylinder having a bore and a piston slidably mounted in said bore, said cylinder having fluid ports on either side of said piston, said piston having at least one at-rest position with respect to said cylinder; and means for permitting limited relative reciprocating movement between said piston and said cylinder about said at-rest position, said means comprising hydraulic fluid passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said zone being of a length greater than the axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connectable to said reservoir.

Claim 17

A combination according to claim 13 wherein said passage means comprises a pair of interconnected ports longitudinally spaced apart from each other with respect to said cylinder and with the spacing between said ports defining the length of said zone.

Claim 18

A combination according to claim 14 wherein said ports are provided in said cylinder and communicate with said cylinder bore and are interconnected by a passage located externally of said cylinder bore.

Claim 19

A combination according to claim 14 wherein each of said ports takes the form of at least one space between the wall of said cylinder bore and said piston and are interconnected by a passage in the form of a space between the wall of said cylinder bore and piston.

Claim 20

A combination according to claim 16 wherein said passage takes the form of at least one longitudinal groove formed in the bore of said cylinder.

Claim 21

A combination according to claim 16 wherein said passage takes the form of an annular widening formed in the bore of said cylinder.

Claim 22

A combination according to claim 16 wherein said passage takes the form of at least one helical groove formed in the bore of said cylinder.

Claim 23

A combination according to claim 14 including a piston rod having a pair of spaced apart stops, said piston being slidably movable on said rod between said stops; and wherein each of said ports is located adjacent a stop and takes the form of a space between said piston rod and said piston.

Claim 24

A combination according to claim 20 wherein said ports are interconnected by a passage formed in the surface of said piston rod.

Claim 25

A combination according to claim 21 wherein said passage takes the form of at least one longitudinal groove.

Claim 26

A combination according to claim 21 wherein said passage takes the form of at least one helical groove.

Claim 27

In a truck having a chassis and a cab pivotably mounted thereon and tiltable angularly between an over-the-road position and a tilted position: a resilient suspension system mounted between said chassis and cab for normally maintaining said cab in an at-rest position with respect to said chassis but permitting limited relative bouncing movement between said cab and chassis; a hydraulic piston-cylinder device pivotally connected to and between said chassis and cab for tilting said cab between its said positions, said device comprising a cylinder having a bore and a piston slidably movable therein, said piston having at least an at-rest position with respect to said cylinder corresponding to the at-rest position of said cab; hydraulic means including a pump for supplying hydraulic fluid to said bore on either side of said piston to effect relative tilting movement between said cab and chassis, said hydraulic means normally preventing relative movement between said piston and cylinder from said at-rest position in response to relative movement between said cab and chassis, said hydraulic means further comprising a reservoir; and means for permitting limited reciprocating movement between said piston and said cylinder in response to relative movement between said cab and said chassis about their at-rest positions, said means comprising passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said zone being of a length greater than the axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connected to said reservoir.

Claim 28

In a truck having a chassis and a cab pivotably mounted thereon and tiltable angularly between an over-the-road position and a tilted position: a resilient suspension system mounted between said chassis and cab for normally maintaining said cab in an at-rest position with respect to said chassis but permitting limited relative bouncing movement between said cab and chassis; a hydraulic piston-cylinder device pivotally connected to and between said chassis and cab for tilting said cab between its said positions, said device comprising a cylinder having a bore and a piston slidably movable therein, said piston having at least an at-rest position with respect to said cylinder corresponding to the at-rest position of said cab; hydraulic means including a pump for supplying hydraulic fluid to said bore on either side of said piston to effect relative tilting movement between said cab and chassis, said hydraulic means normally preventing relative movement between said piston and cylinder from said at-rest position in response to relative movement between said cab and chassis, said hydraulic means further comprising a reservoir; and means for permitting limited reciprocating movement between said piston and said cylinder in response to relative movement between said cab and said chassis about their at-rest positions, said means comprising passage means affording communication between opposite sides of said piston in a zone which includes said at-rest position of said piston and cylinder, said zone being of a length greater than the axial length of said piston to allow for lost motion movement of said piston in opposite directions, said passage means permitting fluid flow in opposite directions therethrough and said passage means being connected to said reservoir.

Claim 29

A combination according to claim 24 wherein said passage means comprises a pair of interconnected ports longitudinally spaced apart from each other with respect to said cylinder and with the spacing between said ports defining the length of said zone.

Claim 30

A combination according to claim 25 wherein said ports are provided in said cylinder and communicate with said cylinder bore and are interconnected by a passage located externally of said cylinder bore.

Claim 31

A combination according to claim 25 wherein each of said ports takes the form of at least one space between the wall of said cylinder bore and said piston and are interconnected by a passage in the form of a space between the wall of said cylinder bore and said piston.

Claim 32

A combination according to claim 27 wherein said passage takes the form of at least one longitudinal groove formed in the bore of said cylinder.

Claim 33

A combination according to claim 27 wherein said passage takes the form of an annular widening formed in the bore of said cylinder.

Claim 34

A combination according to claim 27 wherein said passage takes the form of at least one helical groove formed in the bore of said cylinder.

Claim 35

A combination according to claim 25 including a piston rod having a pair of spaced apart stops, said piston being slidably movable on said rod between said stops; and wherein each of said ports is located adjacent a stop and takes the form of a space between said piston rod and said piston.

Claim 36

A combination according to claim 31 wherein said ports are interconnected by a passage formed in the surface of said piston rod.

Claim 37

A combination according to claim 32 wherein said passage takes the form of at least one longitudinal groove.

Claim 38

A combination according to claim 32 wherein said passage takes the form of at least one helical groove.