Friction-welded hydraulic actuator

Claim 2

A hydraulic actuator of the kind in which a piston head on a piston rod reciprocates within a cylinder between end members at opposite ends of the cylinder and comprising, a friction weld between the cylinder and one of the end members and including a bead of flash projecting radially inwardly into the interior of the cylinder, and flash-accommodating means on the piston head for permitting the piston head to move axially within the cylinder into abutment with the end wall without engaging the inwardly projecting bead of flash, whereby the actuator can be assembled and operated without the need to remove the internal flash formed by the friction weld.

Claim 3

The invention defined in claim 1 wherein the flash-accommodating means include an annular groove in the outer periphery of the surface of the piston head facing the friction welded end member.

Claim 4

The invention defined in claim 1 wherein the flash-accommodating means include an axially extending projection on the central part of the surface of the piston head facing the friction-welded member.

Claim 5

A hydraulic actuator assembly as set forth in claim 1 and further including a recessed portion in the center of the piston head where the piston rod is welded to the piston head, said recessed portion forming a trap for weld flash produced by the friction weld.

Claim 6

A hydraulic actuator assembly as set forth in claim 1 and further including a friction weld between the piston head and piston rod, a recessed portion on the center of the piston head where the piston rod is welded to the piston head, said recessed portion forming a trap for weld flash produced by the friction weld.

Claim 7

A hydraulic actuator assembly as set forth in claim 1 including a friction weld between the piston head and piston rod, and wherein the piston rod is steel and the piston head is formed of cast iron and has a steel insert integrally cast in the center thereof where the piston rod is friction welded thereto.

Claim 8

A hydraulic actuator aSsembly as set forth in claim 1 and further including a central bore formed through the piston head, a portion of said piston rod extending into a first end of the piston head bore, stop means formed between the piston rod and piston head to limit the extension of the piston rod into the piston head bore, and a plug member having a portion extending into a second end of the bore and friction welded to the piston rod to maintain the piston head in a fixed position on the piston rod.

Claim 9

A hydraulic actuator which is entirely assembled by friction welding comprising, a cylinder, a first end member friction welded to a first end of the cylinder and having a centrally located hole to receive a piston rod, a second end member friction welded to a second end of the cylinder, each of said end member friction welds having beads of flash projecting inwardly into the interior of the cylinder, a piston assembly reciprocably mounted in said cylinder, said piston assembly comprising a piston head friction welded to a piston rod, and flash-accommodating means on the piston head for permitting the piston head to move axially within the cylinder into abutment with the end walls without engaging the inwardly projecting beads of flash, whereby the actuator can be assembled and operated without the need to remove the internal flash formed by the friction welds.

Claim 10

A hydraulic actuator which is entirely assembled by friction welding comprising, a cylinder, a first end member friction welded to a first end of the cylinder and having a centrally located hole to receive a piston rod, a second end member friction welded to a second end of the cylinder, each of said end member friction welds having beads of flash projecting inwardly into the interior of the cylinder, a piston assembly reciprocably mounted in said cylinder, said piston assembly comprising a piston head friction welded to a piston rod, and flash-accommodating means on the piston head for permitting the piston head to move axially within the cylinder into abutment with the end walls without engaging the inwardly projecting beads of flash, whereby the actuator can be assembled and operated without the need to remove the internal flash formed by the friction welds.

Claim 11

A hydraulic actuator as set forth in claim 8 and further comprising a central bore formed through the piston head, a portion of said piston rod extending into a first end of the piston head bore, stop means formed between the piston rod and piston head to limit the extension of the piston rod into the piston head bore, and a plug member having a portion extending into a second end of the bore and friction welded to the piston rod to maintain the piston head in a fixed position on the piston rod.

Claim 12

A hydraulic actuator as set forth in claim 9 wherein the flash-accommodating means include an annular groove formed on the outer extremity of the first end face of the piston head.

Claim 13

A hydraulic actuator as set forth in claim 8 wherein the piston rod is steel and the piston head is formed of cast iron and has a steel insert integrally cast in the center thereof where the piston rod is friction welded thereto.

Claim 14

A hydraulic actuator as set forth in claim 8 wherein the flash-aaccommodating means include an annular groove formed on the outer extremity of each end face of the piston head.

Claim 15

A hydraulic actuator as set forth in claim 8 and further including a recessed portion in the center of the piston head where the piston rod is friction welded to the piston head, said recessed portion forming a trap for weld flash produced by the friction weld.

Claim 16

A hydraulic actuator as set forth in claim 13 herein the flash-accommodating means include an annular groove formed on the outer extremity of each face of the piston head.

Claim 17

A hydraulic actuator as set forth in claim 13 wherein the piston rod is steel and the piston head is formed of cast iron and has a steel insert integrally cast in the center thereof where the piston rod is friction welded thereto.

Claim 18

A hydraulic actuator as set forth in claim 15 wherein the flash-accommodating means include an annular groove formed on the outer extremity of each face of the piston head.

Claim 21

A method of making a hydraulic actuator as set forth in claim 17 including forming an annular groove on the outer extremity of each face of the piston head.

Claim 22

A method of making a hydraulic actuator as set forth in claim 17 including forming a recessed portion in the center of the piston head where the piston rod is welded to the piston head, said recessed portion forming a trap for weld flash produced by the friction weld.

Claim 23

A method of making a hydraulic actuator as set forth in claim 19 including forming an annular groove on the outer extremity of each face of the piston head.

Claim 24

A method of making a hydraulic actuator as set forth in claim 17 wherein the piston rod is steel and the piston head is formed of cast iron and has a steel insert integrally cast in the center thereof where the piston rod is friction welded thereto.

Claim 25

A method of making a hydraulic actuator as set forth in claim 21 including forming an annular groove on the outer extremity of each face of the piston head.

Claim 26

A method of making a hydraulic actuator as set forth in claim 21 including forming a recessed portion in the center of the piston head where the piston rod is welded to the piston head, said recessed portion forming a trap for weld flash produced by the friction weld.

Claim 27

A method of making a hydraulic actuator as set forth in claim 23 including forming an annular groove on the outer extremity of each face of the piston head.

Claim 28

A method of making a hydraulic actuator as set forth in claim 17 including forming a central bore in the center of the piston head, inserting a portion of the piston rod into a first end of the piston head bore, forming a stop means between the piston rod and piston head to limit the extension of the piston rod into the piston head bore, and friction welding a plug member extending into a second end of the bore to the piston rod to maintain the piston head in a fixed position on the piston rod.

Claim 29

A method of making a hydraulic actuator as set forth in claim 25 including forming an annular groove on the outer extremity of the first end face of the piston head.