1. A method for adapting stiffness in a variable stiffness actuator comprising:
providing a variable stiffness actuator comprising:
a member configured to transmit motion; and
a fluidic circuit connected to said member, a control fluid circulating within said fluidic circuit,
wherein said fluidic circuit comprises a supply and distribution unit of said control fluid having a reservoir of said control fluid and a pumping unit, and
wherein said supply and distribution unit comprises two distribution lines of said control fluid, said distribution lines being connected with hydraulic pipes to said member such that an increase or decrease in pressure of said control fluid activates said member to transmit said motion;
providing said control fluid comprising a first fluid and a second fluid separate from each other and in proportions according to a predefined ratio; and
adapting a stiffness of said actuator by adapting said pressure of said control fluid into said two distribution lines.
2. The method according to the claim 1, wherein the step of providing said control fluid comprises providing said first fluid as a compressible fluid and said second fluid as an incompressible fluid, and wherein the step of adapting a stiffness of said actuator comprises adapting pressures of said first and second fluids, said first and second fluids being nonmixable.
3. The method according to the claim 1, wherein the step of providing said control fluid comprises providing said first fluid and said second fluid as gases, and wherein the step of adapting a stiffness of said actuator comprises adapting pressures of said first and second gases.
4. The method according to claim 1, further comprising the step of changing pressure of delivery and pressure of return in said two distribution lines in order to keep constant a difference between said pressure of delivery and said pressure of return.
5. The method according to claim 4, further comprising the step of controlling pressures in said two distribution lines with at least one pressure sensor.
6. The method according to claim 4, wherein the step of adapting said pressure of said control fluid is performed in real time.
7. A variable stiffness actuator comprising:
a member configured to transmit motion; and,
a fluidic circuit connected to said member, a control fluid circulating within said fluidic circuit,
wherein said fluidic circuit comprises a supply and distribution unit of said control fluid having a reservoir of said control fluid and a pumping unit,
wherein said supply and distribution unit comprises two distribution lines of said control fluid, said distribution lines being connected with hydraulic pipes to said member such that an increase or decrease in pressure of said control fluid activates said member to transmit said motion, and
wherein said control fluid comprises a first fluid and a second fluid separate from each other and in proportions according to a predefined ratio.
8. The variable stiffness actuator according to claim 7, wherein such first fluid is a compressible fluid and said second fluid is an incompressible fluid (31), said first and second fluids being nonmixable.
9. The variable stiffness actuator according to claim 7, wherein said first fluid and said second fluid are nonmixable gases.
10. The variable stiffness actuator according to claim 7, further comprising a system configured to vary an absolute value of pressure into said two distribution lines, said two distribution lines comprising a distribution line of delivery in a distribution line of return, a difference in pressure between a pressure of said control fluid in said distribution line of delivery and in said distribution line of return being constant.
11. The variable stiffness actuator according to claim 7, wherein said control fluid is a biphasic fluid comprising an incompressible phase of liquid type liquid and a compressible phase gaseous type.
12. The variable stiffness actuator according to claim 7, wherein said first fluid is contained into a closed and sealed container comprised into said two distribution lines, said closed and sealed container being made from an elastically deformable material
13. The variable stiffness actuator according to claim 7, wherein said fluidic circuit comprises at least two accumulators positioned respectively along said two distribution lines, each of said accumulators comprising a first room and a second room, said first room being connected to said fluidic circuit and being filled with said second fluid, said second room being filled with said first fluid, at least said second room being made of an elastically deformable material.
14. The variable stiffness actuator according to claim 13, wherein said two rooms are separated with a diaphragm made of an elastically deformable material.
15. The variable stiffness actuator according to claim 13, further comprising at least one pressure sensor, said pressure sensor being configured to measure pressure into said two rooms.
16. The variable stiffness actuator according to claim 7,
wherein said actuator comprises a double acting hydraulic cylinder,
wherein said two distribution lines are connected respectively to two chambers of said hydraulic circuit within said hydraulic circuit, said chambers being separated by a piston that delivers and returns said control fluid into said two chambers, and
wherein said piston is said member configured to transmit motion.
17. The variable stiffness actuator according to claim 7, wherein said actuator is a rotational hydraulic actuator.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A drilling mast transport skid comprising:
a frame positionable on a transport trailer;
a forward hydraulically actuated slider and a rear hydraulically actuated slider, located on the frame;
the sliders independently movable in substantially perpendicular relationship to the frame;
a vertically extendable elevator attached to the rear slider;
a carriage movably located between the frame and the forward slider for translating the forward slider along the length of the frame; and,
wherein a mast section of a drilling rig may be positioned on the sliders, such that controlled movement of the sliders, the elevator and the carriage can be used to position the mast section for connection to another structure.
2. The drilling mast transport skid according to claim 1, further comprising:
a slide pad located on an upper surface of at least one of the sliders; and,
the slide pad permitting relative movement between the mast section and the slider when articulating the slider.
3. The drilling mast transport skid according to claim 1, further comprising:
a vertically extendable elevator attached to each side of the rearward slider; and,
each elevator being independently movable between a raised and lowered position.
4. The drilling mast transport skid according to claim 1, further comprising:
a roller set between the carriage and the frame to provide a rolling relationship between the carriage and the frame;
a motor connected to the carriage;
a pinion gear connected to the motor;
a rack gear mounted lengthwise on the frame, the rack gear engaging the pinion gear; and,
wherein operation of the motor causes movement of the forward slider lengthwise along the frame.