Line tensioning system

Claim 2

A line tensioning system, comprising: powered drum means engaging the line at opposite ends thereof for alternately spooling and unspooling the line; fluid actuated fixed displacement means connected with at least one of said drum means for applying a force to said one drum means, so as to exert tensioning effort upon the line when unspooled therefrom; and variable displacement means in fluid communication with said fixed displacement means for supplying fluid to and receiving fluid from said fixed displacement means and for maintaining a constant fluid pressure differential between the pressure of said fluid supplied to said fixed displacement means and said fluid received from said fixed displacement means in spite of fluctuations in the pressure of the fluid either received from or supplied to said fixed displacement means, whereby a uniform tensioning effort is exerted on said line during spooling and unspooling by said one drum means.

Claim 3

A line tensioning system as defined in claim 1, including a second fixed displacement means for applying a force to the other of said drum means so as to exert tensioning effort upon the line when unspooled therefrom, said variable displacement means further being operable for supplying fluid to and receiving fluid from said second fixed displacement means and for maintaining a constant fluid pressure differential between the pressure of the fluid supplied to said second fixed displacement means and the pressure of the fluid received from said second fixed displacement means in spite of fluctuations in the pressure of the fluid either received from or supplied to said fixed displacement means occurring during said spooling and unspooling operation, whereby a uniform tensioning effort is exerted on said line during spooling and unspooling by said other drum means.

Claim 4

A line tensioning system comprising: powered drum means engaging the line at opposite ends thereof for alternately spooling and unspooling the lines; and a first fluid actuated fixed displacement means connected with at least one of said drum means for applying a force to said one drum means, so as to exert tensioning effort upon the line when unspooled therefrom; and a second fluid actuated fixed displacement means for applying a force to another of said drum means so as to exert a tensioning effort upon the line when unspooled therefrom; and a variable displacement means for supplying fluid to and receiving fluid from said first and second fixed displacement means for controlling the amount of fluid displaced by said first and second fixed displacement means as the line is unspooled from either drum means, to thereby control the tensioning effort exerted.

Claim 5

A line tensioning system comprising: powered drum means engaging the line at opposite ends thereof for alternately spooling and unspooling the lines; and a first fluid actuated fixed displacement means connected with at least one of said drum means for applying a force to said one drum means, so as to exert tensioning effort upon the line when unspooled therefrom; and a second fluid actuated fixed displacement means for applying a force to another of said drum means so as to exert a tensioning effort upon the line when unspooled therefrom; and a variable displacement means for supplying fluid to and receiving fluid from said first and second fixed displacement means for controlling the amount of fluid displaced by said first and second fixed displacement means as the line is unspooled from either drum means, to thereby control the tensioning effort exerted.

Claim 6

A combination line tensioning and regenerative braking system, comprising a. a first and second winding means for winding and unwinding a line extending therebetween such that as the line is wound onto one winding means it simultaneously is unwound from the other winding means; b. power means for alternately driving said first and second winding means; c. fluid actuated fixed displacement means connected with at least one of said winding means for applying braking effort to said one winding means, so as to exert tensioning effort upon the line as it is unwound therefrom; d. fluid regenerative braking means for converting energy produced by braking the one winding means into energy for supplementing driving force applied to the other winding means by said power means, said fluid regenerative braking means comprising variable displacement means operatively connected with said power means, fluid circuit means interconnecting said fixed and variable displacement means, said variable displacement means being operable for maintaining a pre-selected fluid pressure withing said fluid circuit means such that preselected braking effort is maintained on said one winding means, to thereby control line tension, and further being operable for converting excess fluid pressure in said fluid circuit means into energy which is returned to said power means for supplementing driving force applied to the other winding means.

Claim 7

A combination line tensioning and regenerative braking system, comprising a. a first and second winding means for winding and unwinding a line extending therebetween such that as the line is wound onto one winding means it simultaneously is unwound from the other winding means; b. power means for alternately driving said first and second winding means; c. fluid actuated fixed displacement means connected with at least one of said winding means for applying braking effort to said one winding means, so as to exert tensioning effort upon the line as it is unwound therefrom; d. fluid regenerative braking means for converting energy produced by braking the one winding means into energy for supplementing driving force applied to the other winding means by said power means, said fluid regenerative braking means comprising variable displacement means operatively connected with said power means, fluid circuit means interconnecting said fixed and variable displacement means, said variable displacement means being operable for maintaining a pre-selected fluid pressure withing said fluid circuit means such that preselected braking effort is maintained on said one winding means, to thereby control line tension, and further being operable for converting excess fluid pressure in said fluid circuit means into energy which is returned to said power means for supplementing driving force applied to the other winding means.

Claim 8

The line tensioning system as defined in claim 4, wherein said variable displacement means controls the direction and quantity of fluid flow in said fluid circuit means in response to the fluid pressure differential across said fixed displacement means.

Claim 9

A line tensioning system as defined in claim 5, wherein said variable displacement means includes differential operator means responsive to said fluid pressure differential for controlling the quantity and direction of fluid displaced by said variable displacement means, so as to maintain a pre-selected fluid pressure differential across said fixed displacement means.

Claim 10

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction, and variable displacement hydraulic actuator means in fluid communication with said fixed displacement hydraulic actuator means for conveying fluid to and receiving fluid from said fixed displacement means and for maintaining a preselected constant pressure differential between the pressure of the fluid conveyed to and the pressure of the fluid received from said fixed hydraulic actuator means during said winding and unwinding operation, whereby a uniform tensioning effort is exerted by said fixed displacement hydraulic actuator means.

Claim 11

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction, and variable displacement hydraulic actuator means in fluid communication with said fixed displacement hydraulic actuator means for conveying fluid to and receiving fluid from said fixed displacement means and for maintaining a preselected constant pressure differential between the pressure of the fluid conveyed to and the pressure of the fluid received from said fixed hydraulic actuator means during said winding and unwinding operation, whereby a uniform tensioning effort is exerted by said fixed displacement hydraulic actuator means.

Claim 12

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; and means for maintaining fluid pressure upon said fixed displacement hydraulic actuator means to thereby exert tensioning effort upon the line when the other winding device is stationary; and variable displacement hydraulic actuator means in fluid communication with said fixed displacement hydraulic actuator means for controlling the amount of hydraulic fluid displaced by said fixed displacement hydraulic actuator means, to thereby control the tensioning effort exerted by said fixed displacement hydraulic actuator means.

Claim 13

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; and means for maintaining fluid pressure upon said fixed displacement hydraulic actuator means to thereby exert tensioning effort upon the line when the other winding device is stationary; and variable displacement hydraulic actuator means in fluid communication with said fixed displacement hydraulic actuator means for controlling the amount of hydraulic fluid displaced by said fixed displacement hydraulic actuator means, to thereby control the tensioning effort exerted by said fixed displacement hydraulic actuator means.

Claim 14

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; and variable displacement hydraulic actuator means in fluid communication with said fixed displacement hydraulic actuator means for controlling the amount of hydraulic fluid displaced by said fixed displacement hydraulic actuator means, and for selectively increasing and decreasing the tensioning effort exerted by said fixed displacement hydraulic actuator means.

Claim 15

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; and variable displacement hydraulic actuator means in fluid communication with said fixed displacement hydraulic actuator means for controlling the amount of hydraulic fluid displaced by said fixed displacement hydraulic actuator means, and for selectively increasing and decreasing the tensioning effort exerted by said fixed displacement hydraulic actuator means.

Claim 16

A line tensioning system comprising: powered drum means engaging the line at opposite ends thereof for alternately spooling and unspooling the line; fluid actuated fixed displacement means connected with at least one of said drum means for applying a force to said one drum means, so as to exert tensioning effort upon the line when unspooled therefrom; and variable displacement means supplying fluid to and receiving fluid from said fixed displacement means for controlling tensioning effort exerted, said variable displacement means including a variable displacement pump motor in fluid communication with said fixed displacement means, and differential operator means for controlling the quantity and direction of fluid supplied to and received from said fixed displacement means by said variable displacement pump motor.

Claim 17

A line tensioning system comprising: powered drum means engaging the line at opposite ends thereof for alternately spooling and unspooling the line; fluid actuated fixed displacement means connected with at least one of said drum means for applying a force to said one drum means, so as to exert tensioning effort upon the line when unspooled therefrom; and variable displacement means supplying fluid to and receiving fluid from said fixed displacement means for controlling tensioning effort exerted, said variable displacement means including a variable displacement pump motor in fluid communication with said fixed displacement means, and differential operator means for controlling the quantity and direction of fluid supplied to and received from said fixed displacement means by said variable displacement pump motor.

Claim 18

A line tensioning system as defined in claim 10 wherein said variable displacement pump motor is driven by a constant speed prime mover.

Claim 19

A line tensioning system as defined in claim 10 wherein said fixed displacement means includes first and second fluid ports communicating with said variable displacement pump motor, and wherein said differential operator means includes first pressure actuated cylinder means responsive to the pressure differential between said first and second fluid ports for controlling the direction of displacement of said variable displacement pump motor.

Claim 20

A line tensioning system as defined in claim 12 further including force varying means for varying the amount of force applied to said one drum means.

Claim 21

A line tensioning system as defined in claim 13, wherein said force varying means includes second pressure actuated cylinder means controlling the pressure differential between said first and second ports, and control pressure supply means for actuating said second cylinder means to maintain a preselected differential between said first and second fluid ports.

Claim 22

A line tensioning system as defined in claim 14, wherein said control pressure supply means includes a source of pressurized control fluid, and manually controlled valve means connecting said source of pressurized control fluid with said second cylinder means for selectively varying the pressure supplied to said second cylinder means.

Claim 23

A line tensioning system as defined in claim 10, further including pressurized working fluid means for supplying working fluid at a constant pressure to said fixed displacement means and to said variable displacement means.

Claim 24

A line tensioning system as defined in claim 16, wherein said system further includes a check valve means for preventing reverse flow of fluid from said fixed displacement means to said pressurized working fluid means.

Claim 25

A line tensioning system as defined in claim 16, wherein said pressurized working fluid means includes a fixed displacement pump and a constant speed prime mover.

Claim 26

A line tensioning system as defined in claim 16, wherein said fixed displacement means includes first and second fixed displacement ports and said variable displacement means includes first and second variable displacement ports, and further including working fluid conduit means for interconnecting said fixed and variable displacement means with said pressurized working fluid means, said working fluid conduit means including a fluid pressure sump, a first conduit section connecting said first fixed displacement port with said fluid pressure sump, a second conduit section connecting said first variable displacement port with said pressurized working fluid means and a third conduit section connecting said second fixed displacement port with said second variable displacement port.

Claim 27

A line tensioning system as defined in claim 19, wherein said working fluid conduit means includes a heat exchanger and a discharge pressure and flow control means connected in said first conduit section for regulating the pressure in said first conduit section and for regulating the flow of fluid through said heat exchanger.

Claim 28

A line tensioning system as defined in claim 20, wherein said working fluid conduit means further includes a fourth conduit section connected with said second conduit section, said fourth conduit section including a first branch connected with said third conduit section, and further including a check valve means for permitting working fluid to pass in one direction from said fourth into either said first or third conduit section.

Claim 29

A line tensioning system as defined in claim 21, wherein said check valve means includes first and second valves positioned within said first and second branches, respectively, of said fourth conduit section.

Claim 30

A line tensioning system as defined in claim 22, wherein said pressurized working fluid means includes a pilot operated relief valve connected with said second conduit section for maintaining the working fluid at a constant pressure.

Claim 31

A line tensioning system as defined in claim 10, further comprising second fluid actuacted fixed displacement means for applying a force to the other of said drum means, so as to exert tensioning effort upon the line when unspooled therefrom, power means alternately driving said drum means, said power means being operatively connected with said variable displacement means to form a power regenerative braking system in which energy produced by braking either of the drum means is converted into power for supplementing the driving force applied by said power means for driving the other drum means, said power regenerative braking system including a circuit loop between the first-mentioned and second fixed displacement means, said first-mentioned fixed displacement means including first and second fixed displacement ports through which the fluid displaced thereby is passed, said second fixed displacement means including third and fourth fixed displacement ports through which the fluid displaced thereby is passed, said first and third fixed displacement ports being in fluid communication with each other and said second and fourth fixed displacement ports being in fluid communication with each other to form said circuit loop; said variable displacement means being in fluid communication with said circuit loop for supplying fluid to and receiving fluid from said loop for controlling the tensioning effort exerted.

Claim 32

A line tensioning system as defined in claim 24, further including pressurized working fluid means for supplying working fluid at a constant pressure to said first-mentioned and second fixed displacement means and to said variable displacement means, and wherein said variable displacement means includes a variable displacement pump motor in fluid communication with said pressurized working fluid means and said first and third fixed displacement ports, said pump motor being operatively connected with said power means, and differential operator means for varying the direction and quantity of displacement of said variable displacement pump motor in response to the pressure differential between said first and third ports and said second and fourth ports.

Claim 33

A line tensioning system as defined in claim 25, further including force varying means for varying the amount of force applied to said drum means.

Claim 34

A line tensioning system as defined in claim 26, wherein said differential operator means includes an operator cylinder and piston mounted within said cylinder, said operator piston being connected with said variable displacement pump motor for varying the displacement thereof, said operator piston being subjected on opposing sides thereof to the fluid pressure in said first and third ports and said second and fourth ports, respectively, and wherein said force varying means includes a control cylinder, a control piston mounted for travel within said control cylinder and connected with said operator piston, and control pressure supply means connected with said control cylinder for applying a selectable pressure to said control cylinder to thereby apply a selectable pressure to said operator piston, whereby the pre-selected pressure differential maintained between said first and third ports and said second and fourth ports may be varied.

Claim 35

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: power means for alternately applying driving force to the winding devices; fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; and variable displacement hydraulic actuator means responsive to the tensioning effort exerted by said fixed displacement hydraulic actuator means for controlling the tensioning effort exerted, said variable displacement hydraulic actuator means being operatively connected with said power means such that tensioning effort exerted when the line is wound upon the other winding device supplements driving force applied to the other winding device.

Claim 36

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: power means for alternately applying driving force to the winding devices; fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; and variable displacement hydraulic actuator means responsive to the tensioning effort exerted by said fixed displacement hydraulic actuator means for controlling the tensioning effort exerted, said variable displacement hydraulic actuator means being operatively connected with said power means such that tensioning effort exerted when the line is wound upon the other winding device supplements driving force applied to the other winding device.

Claim 37

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: first fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; second fixed displacement hydraulic actuator means connected with the other winding device to exert tensioning effort upon the line as it is wound upon the one winding device and thereby moved in the reverse direction; and variable displacement hydraulic actuator means responsive to the tensioning effort exerted by said first and second fixed displacement hydraulic actuator means for controlling the tensioning effort exerted.

Claim 38

A line tensioning system for tensioning a line extending between two winding devices between which the line is moved in one direction and then in a reverse direction as it is wound upon and unwound from one and then the other winding device, comprising: first fixed displacement hydraulic actuator means connected with one of the winding devices to exert tensioning effort upon the line as it is wound upon the other winding device and thereby moved in the one direction; second fixed displacement hydraulic actuator means connected with the other winding device to exert tensioning effort upon the line as it is wound upon the one winding device and thereby moved in the reverse direction; and variable displacement hydraulic actuator means responsive to the tensioning effort exerted by said first and second fixed displacement hydraulic actuator means for controlling the tensioning effort exerted.

Claim 39

The tensioning system of claim 29 further comprising conduit means hydraulically interconnecting the first-mentioned and second fixed displacement hydraulic actuator means, said conduit means having first and second sections between which a fluid pressure differential is established during operation of the first-mentioned and second fixed displacement means, said variable displacement hydraulic actuator means being responsive to said fluid pressure differential.