US 7,621,241 B2 · Hydraulic-pressure actuated locking mechanism and method

Abstract

A mechanism and method is provided for preventing instantaneous unlatching of a driving and a driven member upon an accidental drop in the hydraulic-holding pressure. One embodiment of the mechanism includes a housing having an inlet port connectable to a substantially sustained high pressure fluid source; and a configured locking pin axially displaceable to an engaged position with respect to the inlet port in response to high pressure fluid entrapped in the housing. The locking pin is spring-biasingly axially displaceable to a disengaged position when the pressure is low. The axial displacement of the locking pin sufficiently overlaps the inlet port to form a variable orifice so that the rate of exhausting of entrapped fluid is variable. In another embodiment, the entrapped fluid is slowly exhausted until a seal length is reduced to zero by the retraction of the locking pin. In another embodiment, latching and unlatching is controlled by pressure pulses. In the latched state, contact between positively-engaged parts negates the need for sustained high fluid pressures.

Claims11

Dependent claims

A hydraulic pressure actuated locking mechanism receiving pressurized fluid from a fluid source, comprising:

a housing including a housing wall defining an inner cavity for receiving a locking pin;
said locking pin being slidably disposed within said inner cavity, movable between a discrete retracted and a discrete extended position;
said locking pin including a cylindrical body having an axial surface and a cylindrical surface;
a mechanical lock system within the locking pin for moving said locking pin between said discrete retracted position and said discrete extended position;
wherein said mechanical lock system includes a first cam member constrained for axial motion within said mechanical lock system;
wherein said mechanical lock system includes a second cam member constrained for axial-rotational motion within said mechanical lock system;
a spring placed within said inner cavity so as to bias said locking pin to said discrete retracted position;
a backplate connected to said housing wall so as to form a chamber between said locking pin and said backplate;
and
wherein said locking pin is axially displaced and held at said discrete extended position by sufficient fluid pressure within said chamber.

7 more elements

A method of locking comprising:

forming a housing including a housing wall defining an inner cavity for receiving a locking pin;
disposing a locking pin slidably within said inner cavity, said locking pin being movable between a retracted position and an extended position through a mechanical lock system within the locking pin;
placing a spring within said inner cavity so as to bias said locking pin to said retracted position;
connecting a backplate to said housing wall so as to form a chamber between said locking pin and said backplate;
receiving pressurized fluid in said chamber from a fluid source, wherein a pressure pulse is formed by said fluid pressure in said chamber rising to a sufficiently high value from a sufficiently low value;
applying said pressure pulse to axially displace a first cam member within said mechanical lock system in order to axially displace and rotate a second cam member;
and
selectively engaging at least one indent on said first cam member with a corresponding prong on a second cam member within said mechanical lock system, thereby converting said axial motion of said first cam member into said axial-rotational motion of said second cam member.

5 more elements

A hydraulic pressure actuated locking mechanism receiving pressurized fluid from a fluid source, comprising:

a housing including a housing wall defining an inner cavity for receiving a locking pin;
said locking pin being slidably disposed within said inner cavity;
a spring placed within said inner cavity so as to bias said locking pin to a retracted position;
a backplate connected to said housing wall so as to form a chamber between said locking pin and said backplate;
wherein said locking pin is axially displaced and held at an extended position by sufficient fluid pressure within said chamber;
a mechanical lock system within the locking pin for moving said locking pin between said retracted position and said extended position, the mechanical lock system including a lock cover;
wherein said mechanical lock system includes a first cam member constrained for axial motion within said lock cover;
and
wherein said mechanical lock system includes a second cam member constrained for axial-rotational motion within said lock cover.

6 more elements

Dependencies are inferred from the claim text.

Hydraulic-pressure actuated locking mechanism and method

Life of this patent

Hydraulic-pressure actuated locking mechanism and method

Life of this patent

Abstract

Claims11