Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
213 words
A linear actuator for an axially movable stem of a valve, comprising, a tubular housing having one end portion fixedly connectable to the valve in surrounding relation to the valve stem and another end portion defining a first seal bore; a rod-like actuator inserted in said housing and having one end attachable to the valve stem and the other end slidably and sealingly engaging said seal bore; a main piston secured to said actuator; said tubular housing defining a first cylindrical chamber cooperable with the periphery of said main piston; means for supplying fluid pressure to said first cylindrical chamber to urge said main piston axially relative to said tubular housing to shift the valve stem; said tubular housing defining a second cylindrical chamber surrounding a medial portion of said actuator; resilient means mounted in said second cylindrical chamber opposing said fluid pressure induced movement of said actuator; said housing further defining a second seal bore interconnecting said first and second cylindrical chambers; a non-compressible liquid filling said second cylindrical chamber; and an auxiliary piston slidably and sealably mounted in said second seal bore, thereby accommodating temperature expansion of said non-compressible liquid in said second cylindrical chamber and permitting axial movements of said actuator without changing the volume of said second cylindrical chamber.
Claim 2
Dependent Claim
213 words
A linear actuator for an axially movable stem of a valve, comprising, a tubular housing having one end portion fixedly connectable to the valve in surrounding relation to the valve stem and another end portion defining a first seal bore; a rod-like actuator inserted in said housing and having one end attachable to the valve stem and the other end slidably and sealingly engaging said seal bore; a main piston secured to said actuator; said tubular housing defining a first cylindrical chamber cooperable with the periphery of said main piston; means for supplying fluid pressure to said first cylindrical chamber to urge said main piston axially relative to said tubular housing to shift the valve stem; said tubular housing defining a second cylindrical chamber surrounding a medial portion of said actuator; resilient means mounted in said second cylindrical chamber opposing said fluid pressure induced movement of said actuator; said housing further defining a second seal bore interconnecting said first and second cylindrical chambers; a non-compressible liquid filling said second cylindrical chamber; and an auxiliary piston slidably and sealably mounted in said second seal bore, thereby accommodating temperature expansion of said non-compressible liquid in said second cylindrical chamber and permitting axial movements of said actuator without changing the volume of said second cylindrical chamber.
Claim 3
Dependent Claim
19 words
An actuator in accordance with claim 1 wherein said resilient means comprises an axially extending stack of Belleville springs.
Claim 4
Dependent Claim
69 words
An actuator in accordance with claim 1 wherein said auxiliary piston is abuttable with said main piston when no substantial fluid pressure exists in said first cylindrical chamber, plus means for introducing a pressured fluid in said second cylindrical chamber to cause said auxiliary piston to axially shift said main piston and actuator in the absence of sufficient fluid pressure in said first cylindrical chamber to effect such shifting.
Claim 5
Dependent Claim
25 words
An actuator in accordance with claim 3 wherein said resilient means comprises an axially extending stack of Belleville springs mounted in said second cylindrical chamber.
Claim 6
Dependent Claim
21 words
An actuator in accordance with claim 1 further comprising means for dampening the fluid pressure produced movement of said rod-like actuator.
Claim 7
Dependent Claim
67 words
An actuator in accordance with claim 1 wherein said auxiliary piston defines an annular dampening chamber communicating with said second cylindrical chamber; and an enlarged diameter portion on said rod-like actuator movable into said dampening chamber when said main piston is actuated to cause a flow of fluid out of said dampening chamber through a constricted annulus defined between said dampening chamber wall and said enlarged-diameter portion.
Claim 8
Dependent Claim
231 words
A linear actuator for an axially movable valve stem projecting out of a valve housing, comprising, in combination, a tubular housing attachable at one end to the valve housing in concentric relation to the valve stem; said tubular housing defining in axially spaced sequence from said one end: (1) a first cylindrical chamber; (2) a first reduced-diameter, axially extending seal bore in fluid communication with said first cylindrical chamber; (3) a second cylindrical chamber in fluid communication with said first seal bore; and (4) a second reduced-diameter, axially extending seal bore communicating with said second cylindrical chamber; a rod-like actuator concentrically mounted in said tubular housing and having its inner end portion attachable to the valve stem and its outer end portion slidably and sealably cooperating with said second seal bore; an annular main piston secured to the inner medial portion of said actuator and slidably and sealably cooperating with the said first cylindrical chamber; means for supplying fluid pressure to the outer face of said annular piston to axially shift said actuator toward the valve housing; an auxiliary annular piston slidably and sealably mounted between said first seal bore and the adjacent portions of said actuator, thereby fluid isolating said first and second cylindrical chambers; said second cylindrical chamber being filled with a non-compressible liquid, whereby said auxiliary piston is shiftable by temperature-induced expansion or contraction of said non-compressible liquid.
Claim 9
Dependent Claim
231 words
A linear actuator for an axially movable valve stem projecting out of a valve housing, comprising, in combination, a tubular housing attachable at one end to the valve housing in concentric relation to the valve stem; said tubular housing defining in axially spaced sequence from said one end: (1) a first cylindrical chamber; (2) a first reduced-diameter, axially extending seal bore in fluid communication with said first cylindrical chamber; (3) a second cylindrical chamber in fluid communication with said first seal bore; and (4) a second reduced-diameter, axially extending seal bore communicating with said second cylindrical chamber; a rod-like actuator concentrically mounted in said tubular housing and having its inner end portion attachable to the valve stem and its outer end portion slidably and sealably cooperating with said second seal bore; an annular main piston secured to the inner medial portion of said actuator and slidably and sealably cooperating with the said first cylindrical chamber; means for supplying fluid pressure to the outer face of said annular piston to axially shift said actuator toward the valve housing; an auxiliary annular piston slidably and sealably mounted between said first seal bore and the adjacent portions of said actuator, thereby fluid isolating said first and second cylindrical chambers; said second cylindrical chamber being filled with a non-compressible liquid, whereby said auxiliary piston is shiftable by temperature-induced expansion or contraction of said non-compressible liquid.
Claim 10
Dependent Claim
31 words
The apparatus of claim 7 further comprising an annular compressible spring mounted in said second cylindrical chamber between said actuator and said tubular housing to oppose inward movement of said actuator.
Claim 11
Dependent Claim
20 words
An actuator in accordance with claim 8 wherein said annular compressible spring comprises an axially extending stack of Belleville springs.
Claim 12
Dependent Claim
69 words
An actuator in accordance with claim 7 wherein said auxiliary piston is abuttable with said main piston when no substantial fluid pressure exists in said first cylindrical chamber, plus means for introducing a pressured fluid in said second cylindrical chamber to cause said auxiliary piston to axially shift said main piston and actuator in the absence of sufficient fluid pressure in said first cylindrical chamber to effect such shifting.
Claim 13
Dependent Claim
21 words
An actuator in accordance with claim 7 further comprising means for dampening the fluid pressure produced movement of said rod-like actuator.
Claim 14
Dependent Claim
68 words
An actuator in accordance with claim 7 wherein said auxiliary piston defines an annular dampening chamber communicating with said second cylindrical chamber; and an enlarged diameter portion on said rod-like actuator movable into said dampening chamber when said main piston is actuated to cause a flow of fluid out of said dampening chamber through a constricted annulus defined between said dampening chamber wall and said enlarged diameter portion.