Hydraulic actuator with mechanical lock and installation

An airplane, comprising:

• a fuselage and a pair of wings projecting laterally outwardly on opposite sides of the fuselage, each wing having an inboard main portion connected to the fuselage and an outboard tip portion which is movable between an in use position in which it is an outboard continuation of the inboard portion of the wing and a folded position in which it extends generally vertically upwardly from the inboard portion of the wing;
• and
• a hydraulic actuator for moving the outboard tip portion of the wing between its spread and folded positions, comprising:
• an elongated cylinder body including a sidewall and end walls together defining an interior space;
• a piston including a piston head within said interior space, said piston head dividing the interior space into two working chambers, one on each side of the piston head, each working chamber adapted to communicate with a hydraulic pressure source for moving said piston axially Within the cylinder body;
• and
• a releasable lock for locking the piston in position relative to the cylinder body, said releasable lock comprising:
• at least one radially extendible/retractable lock bolt carried by said piston head, said lock bolt being normally freed for retraction;
• a complementary lock-bolt cavity within the cylinder body, and
• a locking piston including a bolt block,
• wherein said actuator includes a lock position in which it is desired to lock the piston to the cylinder body, and wherein when the actuator is in such lock position, the lock bolt is extendible radially outwardly into the lock-bolt cavity, and the locking piston is movable axially of the actuator to place the bolt block radially inwardly of the lock bolt, to in such position block the lock bolt against a radial inward movement out from the lock-bolt cavity, the locking piston being axially movable by means of a pressure source separately controllable from the pressure source in communication with the two working chambers.

A hydraulic actuator, comprising:

• an elongated cylinder body including a sidewall and end walls together defining an interior space;
• a piston including a piston head within said interior space, said piston head dividing the interior space into two working chambers, one on each side of the piston head;
• and
• a releasable lock for locking the piston in position relative to the cylinder body, said releasable lock comprising:
• at least one radially extendible/retractable lock bolt carried by said piston head, said lock bolt being normally freed for retraction;
• a complementary lock-bolt cavity within the cylinder body, and
• a locking piston including a bolt block,
• wherein said actuator includes a lock position in which it is desired to lock the piston to the cylinder body, and wherein when the actuator is in such lock position, the lock bolt is extendible radially outwardly into the lock-bolt cavity, and the locking piston is movable axially of the actuator to place the bolt block radially inwardly of the lock bolt, to in such position block the lock bolt against a radial inward movement out from the lock-bolt cavity;
• and
• wherein the bolt block is an annular first end portion of the locking piston, wherein said piston head includes a complementary annular passageway confronting said bolt block, and wherein relative movement of the bolt block into said annular passageway moves the bolt block into its position radially inwardly of the lock bolt.

An airplane, comprising:

• a fuselage and a pair of wings projecting laterally outwardly on opposite sides of the fuselage, each wing having an inboard main portion connected to the fuselage and an outboard tip portion which is movable between an in use position in which it is an outboard continuation of the inboard portion of the wing and a folded position in which it extends generally vertically upwardly from the inboard portion of the wing;
• and
• a hydraulic actuator for moving the outboard tip portion of the wing between its spread and folded positions, comprising:
• an elongated cylinder body including a sidewall and end walls together defining an interior space;
• a piston including a piston head within said interior space, said piston head dividing the interior space into two working chambers, one on each side of the piston head;
• and
• a releasable lock for locking the piston in position relative to the cylinder body, said releasable lock comprising:
• at least one radially extendible/retractable lock bolt carried by said piston head, said lock bolt being normally freed for retraction;
• a complementary lock-bolt cavity within the cylinder body, and
• a locking piston including a bolt block,
• wherein said actuator includes a lock position in which it is desired to lock the piston to the cylinder body, and wherein when the actuator is in such lock position, the lock bolt is extendible radially outwardly into the lock-bolt cavity, and the locking piston is movable axially of the actuator to place the bolt block radially inwardly of the lock bolt, to in such position block the lock bolt against a radial inward movement out from the lock-bolt cavity;
• and
• wherein the bolt block is an annular first end portion of the locking piston, wherein said piston head includes a complementary annular passageway confronting said bolt block, and wherein relative movement of the bolt block into said annular passageway moves the bolt block into its position radially inwardly of the lock bolt.

A hydraulic actuator, comprising:

• an elongated cylinder body including a sidewall and end walls together defining an interior space;
• a piston including a piston head within said interior space, said piston head dividing the interior space into two working chambers, one on each side of the piston head;
• and
• a releasable lock for locking the piston in position relative to the cylinder body, said releasable lock comprising:
• at least one radially extendible/retractable lock bolt carried by said piston head, said lock bolt being normally freed for retraction;
• a complementary lock-bolt cavity within the cylinder body, and
• a locking piston including a bolt block,
• wherein said actuator includes a lock position in which it is desired to lock the piston to the cylinder body, and wherein when the actuator is in such lock position, the lock bolt is extendible radially outwardly into the lock-bolt cavity, and the locking piston is movable axially of the actuator to place the bolt block radially inwardly of the lock bolt, to in such position block the lock bolt against a radial inward movement out from the lock-bolt cavity;
• and
• wherein said cylinder body includes a shoulder, wherein said cylinder body includes a shoulder and wherein a portion of the piston head is substantially against said shoulder when the actuator is in a lock position, and wherein the lock bolt is substantially unloaded when the piston head is against such shoulder, enabling the bolt block to be retracted out from its position radially inwardly of the lock bolt when the lock bolt is unloaded.