US3866696A — Method and apparatus for the control of a weight …

Claim 1

Independent Claim 116 words

In an apparatus adapted to be mounted on a vessel subjected to heave due to wave action, which apparatus includes a piston and hydraulic cylinder and co-acting pneumatic accumulator system for control of the pressure in the hydraulic cylinder, means for connecting a load to said piston, the improvement which comprises means adapted to pass liquid under pressure from a source of liquid to the accumulator system, during that portion only of the heave when the volume of the liquid in the accumulator tends to decrease, a reservoir, means for withdrawing liquid from the accumulator to said reservoir during that portion only of the heave when the volume of liquid in the accumulator tends to increase.

Claim 2

Dependent Claim 116 words

In an apparatus adapted to be mounted on a vessel subjected to heave due to wave action, which apparatus includes a piston and hydraulic cylinder and co-acting pneumatic accumulator system for control of the pressure in the hydraulic cylinder, means for connecting a load to said piston, the improvement which comprises means adapted to pass liquid under pressure from a source of liquid to the accumulator system, during that portion only of the heave when the volume of the liquid in the accumulator tends to decrease, a reservoir, means for withdrawing liquid from the accumulator to said reservoir during that portion only of the heave when the volume of liquid in the accumulator tends to increase.

Claim 3

Dependent Claim 50 words

In the apparatus of claim 1, control means for selectively opening communication betwEen the accumulator and said source and selectively closing communication between the accumulator and said reservoir when said first mentioned communication is opened and control means for opening said second mentioned communication and closing said first mentioned communication.

Claim 4

Dependent Claim 96 words

In the apparatus of claim 2 said control means comprising a signal means responsive to the force imposed in said cylinder on the piston during all portions of the heave, said signal means including means to generate a signal responsive to the forces on the said piston, means to generate a signal responsive to the forces predetermined to be maintained on the piston, means to generate an error signal responsive to the differences between said first and second mentioned signals and means to selectively open and selectively close the aforesaid communications responsive to said error signal.

Claim 5

Dependent Claim 93 words

In the apparatus of claim 1, means adapted to suspend the said cylinder from drilling lines, pipe connection between the cylinder and said accumulator, a gas connection to the accumulator connected to a source of gas under pressure, a pipe connection between said cylinder and said accumulator and said source, pipe connection between said accumulator and said reservoir, valves in each of said pipe connections, means to open and close the valves in one of said pipe connections and means to close and open the valve in the other of said pipe connections.

Claim 6

Dependent Claim 77 words

In the apparatus of claim 4 said means to open and close said valves, including means to sense the force on the piston in said cylinder, and said means to acting to open the valve in said pipe connection when the said force is substantially below a predetermined value and said means to open the valve on the pipe connection to said reservoir acting when the force exerted on said piston is substantially above said predetermined value.

Claim 7

Dependent Claim 96 words

In the apparatus of claim 5 said control means comprising a signal means responsive to the forces imposed on the piston in said cylinder, during all portions of the heave, said signal means including means to generate a signal responsive to the forces on the said piston, means to generate a signal responsive to the forces predetermined to be maintained on the piston, means to generate an error signal responsive to the differences between said first and second mentioned signals and means to selectively open and selectively close the aforesaid connection responsive to said error signal.

Claim 8

Dependent Claim 118 words

In combination with a drilling vessel, a derrick, drilling lines suspended from said derrick, a hydraulic cylinder suspended from said drilling lines, a piston in said cylinder, means to connect a load to said piston, pneumatic accumulator system for control of the pressure in the hydraulic cylinder, liquid reservoir, the improvement which comprises communication means adapted to pass liquid under pressure from the liquid reservoir to the accumulator system during that portion only of the heave when the volume of the liquid in the accumulator tends to decrease, and communication means for withdrawing liquid from the accumulator to said reservoir during that portion only of the heave when the volume of liquid in the accumulator tends to increase.

Claim 9

Dependent Claim 118 words

In combination with a drilling vessel, a derrick, drilling lines suspended from said derrick, a hydraulic cylinder suspended from said drilling lines, a piston in said cylinder, means to connect a load to said piston, pneumatic accumulator system for control of the pressure in the hydraulic cylinder, liquid reservoir, the improvement which comprises communication means adapted to pass liquid under pressure from the liquid reservoir to the accumulator system during that portion only of the heave when the volume of the liquid in the accumulator tends to decrease, and communication means for withdrawing liquid from the accumulator to said reservoir during that portion only of the heave when the volume of liquid in the accumulator tends to increase.

Claim 10

Dependent Claim 94 words

In the apparatus of claim 7, said communication means comprising a signal means responsive to the forces imposed on the piston in said cylinder, during all portions of the heave, said signal means including means to generate a signal responsive to the forces in said cylinder, means to generate a signal responsive to the pressure predetermined to be maintained in the cylinder, means to generate an error signal responsive to the differences between said first and second-mentioned signals and means to selectively open and selectively close the aforesaid communications responsive to said error signal.

Claim 11

Dependent Claim 78 words

In the apparatus of claim 8, means to suspend the said cylinder from the drilling lines, pipe connection between the cylinder at a point below the piston and said accumulator, a gas conNection between the accumulator adapted to be connected to a source of gas under pressure, a pipe connection between the cylinder and accumulator and said reservoir; valves in each of said pipe connections and means to close and open the valves in the said pipe connections.

Claim 12

Dependent Claim 85 words

In the apparatus of claim 9, said means to open and close said valves, including means to sense the force on the piston in said cylinder on said piston, and said means to open the valve in said pipe connection to the said source operative to open said valve when the said sorce is substantially below a predetermined value and means to open the valve on the pipe connection to said reservoir when the force exerted on said piston is substantially above said predetermined value.

Claim 13

Independent Claim 154 words

A method of controlling the spacial displacement of a piston rod which is mounted for vertical displacement on a vessel subject to wave action, a cylinder in which said piston is reciprocally mounted in said cylinder and in which said piston is subject to be loaded by a weight connected to said piston, which load is opposed by liquid under pressure in said cylinder under the said piston, communicated from a body of liquid under gas pressure, the steps of withdrawing liquid from said accumulator to the said body of liquid and to a body of liquid extraneous to the cylinder and accumulator maintained at a substantially lower pressure than the aforesaid gas pressure, when the volume in said cylinder under the piston is decreasing and adding liquid to said accumulator when the body of liquid in said cylinder is increasing whereby the liquid in said accumulator is maintained at a substantially constant volume.

Claim 14

Independent Claim 154 words

A method of controlling the spacial displacement of a piston rod which is mounted for vertical displacement on a vessel subject to wave action, a cylinder in which said piston is reciprocally mounted in said cylinder and in which said piston is subject to be loaded by a weight connected to said piston, which load is opposed by liquid under pressure in said cylinder under the said piston, communicated from a body of liquid under gas pressure, the steps of withdrawing liquid from said accumulator to the said body of liquid and to a body of liquid extraneous to the cylinder and accumulator maintained at a substantially lower pressure than the aforesaid gas pressure, when the volume in said cylinder under the piston is decreasing and adding liquid to said accumulator when the body of liquid in said cylinder is increasing whereby the liquid in said accumulator is maintained at a substantially constant volume.

Claim 15

Dependent Claim 39 words

The method of claim 11, the step of advancing the piston spacially downward during each portion of the heave cycle and withdrawing from said accumulator to an extraneous point a quantity of liquid responsive to the said spacial advance.

Claim 16

Dependent Claim 27 words

In the process of claim 12, said withdrawal occurring only during that portion of the heave when the volume under the piston in the cylinder is decreasing.

Claim 17

Dependent Claim 40 words

In the process of claim 13, said liquid introduction into the accumulator of liquid being in quantity less than the quantity withdrawn, said introduction occurring only during that portion of the heave when said volume in said cylinder is increasing.

Claim 18

Independent Claim 111 words

A method of drilling in submarine environment from a vessel subject to heave as a result of wave action which comprises suspending a drill string connected to a drill bit from a cylinder and piston, mounted on drilling lines suspended in a drill derrick, maintaining said piston under pressure from a pneumatic accumulator connected to said cylinder, advancing said drill string into the earth, continuously removing from said cylinder and accumulator during the period of said heave a volume of fluid displaced from said cylinder by the advance of said drill string into the earth while maintaining a substantially constant pressure in said cylinder during said advance and during said heave.

Claim 19

Independent Claim 111 words

A method of drilling in submarine environment from a vessel subject to heave as a result of wave action which comprises suspending a drill string connected to a drill bit from a cylinder and piston, mounted on drilling lines suspended in a drill derrick, maintaining said piston under pressure from a pneumatic accumulator connected to said cylinder, advancing said drill string into the earth, continuously removing from said cylinder and accumulator during the period of said heave a volume of fluid displaced from said cylinder by the advance of said drill string into the earth while maintaining a substantially constant pressure in said cylinder during said advance and during said heave.

Claim 20

Dependent Claim 127 words

In the method of claim 15, said maintenance of substantially constant pressure comprising withdrawing liquid from the cylinder to a body of liquid under gas pressure in said accumulator during that portion of the heave when the volume of said cylinder under the piston is decreasing due to the heave and transferring liquid from the said body of liquid to the cylinder when the volume in the cylinder under the piston is increasing and withdrawing from said cylinder and body of liquid, a volume of liquid during each portion of said heave substantially equivalent to the volume of liquid displaced in said cylinder by the said advance, the volume of liquid in said cylinder and said body decreasing with time while maintaining the said pressure substantially constant.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-02-17	1978-08-19	1979-02-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-02-17	1982-08-19	1983-02-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-02-17	1986-08-19	1987-02-18	$7700.00	Window Closed / Lapsed

Method and apparatus for the control of a weight suspended from a floating vessel

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