Linear fluidic actuator
First Claim
1. A linear fluidic actuator comprising a tubular envelope closed at opposite ends and inflatable from a flat deflated condition to a certain maximum circular diameter, and a flexible inextensible tension means of fixed length carrying said tubular envelope in a position such that the longitudinal axis of the inflated envelope is transverse to the line of action of said tension means, whereas the diametral axis of the deflated envelope lies in a plane paralleling said line of action, one end of said tension means being fixed in position and the other end being movable linearly toward the fixed end responsively to inflation of the tubular envelope from a flat to a circular configuration.
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Abstract
The specification describes a linear fluidic actuator comprising a plurality of expansible tubes or tubular envelopes closed at opposite ends and coupled in a chain and arranged to have one end of the chain anchored while the other end is adapted to move and exert a tensile force upon inflation of one or more of the tubes, as by compressed air, into a circular diameter, in accordance with the degree of contraction of the chain of tubes. A variation of the actuator utilizes the contracting force of the chain of tubes to effect compression of one or more caged springs, the compressive force of which is illustratively shown and described as actuating a floating member to operate a valve device of the gate or plug type. Also disclosed are modifications utilizing a plurality of parallel-related chains of tubes and tubes expansible to different diameters for utilizing different inflating pressures.
51 Citations
14 Claims
- 1. A linear fluidic actuator comprising a tubular envelope closed at opposite ends and inflatable from a flat deflated condition to a certain maximum circular diameter, and a flexible inextensible tension means of fixed length carrying said tubular envelope in a position such that the longitudinal axis of the inflated envelope is transverse to the line of action of said tension means, whereas the diametral axis of the deflated envelope lies in a plane paralleling said line of action, one end of said tension means being fixed in position and the other end being movable linearly toward the fixed end responsively to inflation of the tubular envelope from a flat to a circular configuration.
- 5. A linear fluidic actuator comprising a plurality of tubular envelopes closed at opposite ends and inflatable individually and collectively with fluid under pressure from a flat deflated condition to a certain maximum cross sectional area circular in form, and flexible tension means of fixed length carrying said tubular envelopes serially in spaced parallel relation with the longitudinal axes of said envelopes being transverse to the line of action of said tension means, one end of said tension means being anchored in a fixed position and the other end being activated linearly toward said one end in accordance with the contraction of said tension means in consequence of inflation of said tubular envelopes toward a circular configuration.
- 8. A fluid pressure controlled operating device, comprising a pair of spaced abutments, one of which occupies a fixed position and the other of which is movable relative to said one abutment, coil spring means interposed under compression between said abutments and acting to bias said movable abutment away from the fixed abutment, and inflatable means comprising a plurality of end-closed tubes of elastomeric material arranged in a row in parallel relation and a sleeve of woven fabric surrounding each of said tubes to limit inflation thereof to a certain maximum circular cross-sectional area, said inflatable means being tautly stretched in flat deflated condition between said abutments in which condition it sustains the expansion force of said spring means and effective when inflated from a flat deflated condition to an inflated circular cross-section to exert a compression force on said spring means and a corresponding movement of said movable abutment toward said fixed abutment.
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10. A fluid pressure controlled operating device, comprising a pair of spaced abutments, one of which occupies a fixed position and the other of which is movable relative to said one abutment, coil spring means interposed under compression between said abutments and acting to bias said movable abutment away from the fixed abutment, inflatable means comprising a plurality of spaced rows of parallel tubes of elastomeric material, each tube having therearound a sleeve of woven fabric to limit inflation of the tube to a certain maximum circular area in cross section, and a pair of sheets of woven wire fabric means disposed at a right angle to said tubes supports and connects the tubes of each row tautly between said abutments, indivudual and collective inflation of corresponding tubes of each row simultaneously into circular cross-section creating a step-by-step contracting force active through said sheets of fabric means effective to overcome and compress said spring means.
- 11. A gate valve having a valve body, a gate valve element movable between a full open and a closed position, and an operating stem for said valve element projecting out of said body, wherein the improvement comprises an operator for said valve element comprising a pair of spaced abutments one of which is fixed relative to said valve body and the other of which is movable relative thereto to which said operating stem is secured, spring means compressed between the said pair of abutments and biasing said movable abutment and said stem to move said valve element to closed position, and tubular elastomeric means interposed between said fixed and movable abutments and inflatable from a flat deflated condition to a certain maximum circular cross-sectional area, said tubular elastomeric means having its longitudinal axis at a right angle to the line of action of said spring means, and tension means comprising a pair of inextensible sheets of fabric material secured together and supporting said tubular elastomeric means therebetween, said sheets having their opposite ends connected to said pair of abutments respectively, said tubular elastomeric means being effective when fully inflated to circular form to act through said tension means to shorten the linear distance between said abutments and thereby effect opening travel of said valve element in opposition to said spring means.
Specification