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US 4,233,000 AGranted
Variable ratio intensifier
AssigneeHalliburton Company
InventorBruce M. Cox
Life of this patent
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AssigneeHalliburton Company
InventorBruce M. Cox
Estimating the term…
An improved differential pressure hydraulic pressure convertor whose ratio of output pressure to input pressure may be easily varied comprising a valve housing, a pump housing having a cylindrical bore therethrough, a power cylinder including a differential piston located between the valve housing and the pump housing, a piston assembly detachably secured to the differential piston of the power assembly and, optionally, a sleeve installed in the cylindrical bore in the pump housing slidably receiving the piston of the piston assembly.
An improved hydraulic pressure convertor including a body having an inlet and an outlet, a motor assemblage carried by the body and including a power cylinder and a differential driving piston reciprocable therein, a pumping assemblage, means connecting the differential driving piston to the pumping assemblage, a first conduit in continuous communication at one end with the inlet and with the power cylinder at the side of the differential driving piston to which fluid pressure is to be applied for driving the differential driving piston on its power stroke, a second conduit continuously in communication at one end with the power cylinder at the opposite side of the differential driving piston, each of said conduits having a valving port spaced from its said one end, a valve operative in a first operating position in which it blocks the valving port of the first conduit and concurrently connects the valving port of the second conduit with the outlet and operative in a second operating position in which it effects communication of said ports with each other and concurrently stops communication of the second port with the outlet, lost motion connecting means connecting the valve to the differential piston so as to effect actuation of the valve toward said first operating position past a predetermined center position as the differential piston is moved a predetermined distance on its power stroke and to effect actuation of the valve toward said second operating position past said center position as the differential piston is moved a predetermined distance on its return stroke, and over-center spring means connected to the valve and operative when the valve is actuated past said center position in directions toward said first and second operating positions, respectively, to drive the valve with a snap action to the one of the said first and second operating positions toward which the valve was being actuated as it passed said center position, wherein the improvement comprises:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Drawings are temporarily unavailable. Open the PDF at USPTO
With single cylinder, double-acting piston: one side of the double-acting piston being always under the influence of the liquid under pressure
Joints and connections: including spaced, diverse connections
Positive-displacement engines driven by liquids
Technical subjects covered by former us classification
Term ended 17 Apr 1998 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to an improved differential pressure hydraulic power convertor. More specifically, the present invention relates to an improved differential pressure hydraulic power convertor having interchangeable piston assemblies and sleeves to easily vary the ratio of the output fluid pressure to the input fluid pressure of the convertor.
The prior art discloses hydraulic pressure convertors employing differential pistons which, on the power stroke, operate a pump which delivers fluid under pressure at a higher pressure than the line pressure supplied from a pressurized source. In these prior art devices, valve means connect the power cylinder at both sides continuously to the fluid pressure source and alternately connect the cylinder at opposite sides of the piston to each other. Such prior art devices are exemplified in U.S. Pat. Nos. 2,749,886 and 3,589,839. Typically, in these devices, the piston is driven on its power stroke by the differential in total pressure on its opposite sides and is driven on its return stroke by full line pressure applied to one side while the other side is vented to exhaust pressure.
However, these prior art devices do not use the potential of the line pressure to the best advantage, do not operate to effect as rapid a return as desirable of the differential piston after completion of its power stroke, do not provide a regenerative circuit for the transfer of fluid pressure from the power side of the differential piston to the opposite side of the piston during the return stroke, and cannot be easily converted from one ratio to another desired ratio of output fluid pressure to the input fluid pressure.
The foregoing advantages and the preferred embodiments of the invention will be better understood from the following specification taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a view of a prior art differential pressure hydraulic power convertor.
FIG. 2 is a cross-sectional view along line 2--2 of the prior art differential pressure hydraulic power convertor shown in FIG. 1.
Referring to FIG. 1 of the drawings, a typical prior art differential pressure hydraulic convertor is shown. The convertor comprises a body 1 composed of a valve housing 2, a pump housing 3, and a power cylinder 4 therebetween and communicating therewith. The valve housing 2 may be formed of a main body portion 5 closed at its outer end by a cover 6 in sealed relation thereto.
Referring to FIG. 2, mounted within the cylinder 4 for reciprocation axially thereof is a differential piston 8 having a stem 9 at the end adjacent the pump housing 3 and having a stem 10 at its opposite end. The valve housing 2 has an internal bore 11 coaxial with, and connected at its inner end to the adjacent end of, the cylinder 4. At the opposite end of the bore 11 and in communication therewith is a valving cavity 12 in which valve means, later to be described, are provided for controlling reciprocation of the piston 8 and regenerative circuitry. At the opposite end of the cylinder 4 from the valve housing 2, the body is provided with a bore 14, coaxial with the cylinder 4, in which the stem 9 is received.
The stem 10 fits the bore 11 with the normal operating clearance sufficient to guide the piston 8 in an axial path. The stem 10 is provided with a circumferential groove 15 in which an O-ring 16 is disposed for effecting a seal to prevent the escape of pressurized fluid from the cylinder 4 into the cavity 12.