US3773991A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Snap action pressure responsive control device with single stroke make and break
Assignee: Siemens Energy and Automation Inc
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Filing: 1971-07-09
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Granted: 1973-11-20
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Expires: 1991-07-09
Abstract
Abstract The application discloses a pressure controlled switch which includes a plunger actuated by a fluid pressure responsive diaphragm. A pair of coil springs having different spring rates oppose the movement of the plunger caused by the diaphragm. The springs are dimensioned to exert different movement resisting forces over different portions of the length of travel of the plunger and in cooperation with a spring contact structure provide low pressure dropout values, high pressure cutout values and intermediate pressure cut-in values operating the switch.
Inventors
- 👤 I Krieger
- 👤 J Peluchiwski
- 👤 D Willcox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:53
CPC Classifications
H; H01; H01H; H01H35/00; H01H35/24; H01H35/26; H01H35/2607; H01H35/2614; H01H35/34
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
419 words
A pressure responsive device comprising a housing having an opening for permitting the entry of fluid into the housing, a movable diaphragm mounted in said housing dividing said housing into a first portion and a second portion receiving fluid entering through said opening, a stationary contact mounted on said housing in said first portion, a movable contact blade formed of spring material fixedly mounted at one end thereof to said housing within said first portion thereof with its free end extending toward said stationary contact and provided wiTh a movable contact at its free end, said movable contact having a center leg and a pair of outside legs, said outside legs bent so as to exert a force normally causing said center leg to be bowed in a direction away from said stationary contact, a plunger mounted in said first portion of said housing and having a first end and a second end, said first end of said plunger extending toward said diaphragm and bearing against said movable contact blade whereby movement of said diaphragm in response to variations of fluid pressure in said housing exerts a force on said plunger to cause it to move, a first spring mounted in said housing and extending between said second end of said plunger and a wall of said housing exerting a force of a first magnitude on said plunger over a first portion of its movement opposing the force exerted by said diaphragm, a second spring mounted in said housing and extending between said wall of said housing and said second end of said plunger exerting a force of a second and greater magnitude on said second end of said plunger over a second portion of its movement opposing the force exerted by said diaphragm, said first spring normally urging said movable contact blade away from said stationary contact, said diaphragm upon movement in response to the pressure of fluid entering through said opening causing said plunger and said movable contact blade to be moved against the force of said first spring and causing said movable contact to engage said stationary contact, further movement of said diaphragm in response to increased fluid pressure acting thereon causing said plunger to move further until its further movement is limited by the force exerted by said second spring and said center leg is bowed in the direction of said stationary contact to exert a force on the said free end of said movable contact to cause it to separate from said stationary contact.
Claim 2
Dependent Claim
419 words
A pressure responsive device comprising a housing having an opening for permitting the entry of fluid into the housing, a movable diaphragm mounted in said housing dividing said housing into a first portion and a second portion receiving fluid entering through said opening, a stationary contact mounted on said housing in said first portion, a movable contact blade formed of spring material fixedly mounted at one end thereof to said housing within said first portion thereof with its free end extending toward said stationary contact and provided wiTh a movable contact at its free end, said movable contact having a center leg and a pair of outside legs, said outside legs bent so as to exert a force normally causing said center leg to be bowed in a direction away from said stationary contact, a plunger mounted in said first portion of said housing and having a first end and a second end, said first end of said plunger extending toward said diaphragm and bearing against said movable contact blade whereby movement of said diaphragm in response to variations of fluid pressure in said housing exerts a force on said plunger to cause it to move, a first spring mounted in said housing and extending between said second end of said plunger and a wall of said housing exerting a force of a first magnitude on said plunger over a first portion of its movement opposing the force exerted by said diaphragm, a second spring mounted in said housing and extending between said wall of said housing and said second end of said plunger exerting a force of a second and greater magnitude on said second end of said plunger over a second portion of its movement opposing the force exerted by said diaphragm, said first spring normally urging said movable contact blade away from said stationary contact, said diaphragm upon movement in response to the pressure of fluid entering through said opening causing said plunger and said movable contact blade to be moved against the force of said first spring and causing said movable contact to engage said stationary contact, further movement of said diaphragm in response to increased fluid pressure acting thereon causing said plunger to move further until its further movement is limited by the force exerted by said second spring and said center leg is bowed in the direction of said stationary contact to exert a force on the said free end of said movable contact to cause it to separate from said stationary contact.
Claim 3
Dependent Claim
71 words
A pressure responsive device as set forth in claim 1 wherein said center leg is provided with an opening therein, said first end of said plunger passes through said center leg opening, and a sleeve axially movable on and encompassing said first end of said plunger on the side of said center leg facing said diaphragm and normally engaging said diaphragm to transmit motion of said diaphragm to said center leg.
Claim 4
Dependent Claim
56 words
A pressure responsive device as set forth in claim 2 wherein said first spring is constituted by a coil spring and has a first and relatively low spring rate and said second spring is constituted by a second coil spring having a second and relatively high spring rate and said second spring surrounds said first spring.
Claim 5
Dependent Claim
41 words
The pressure responsive device of claim 3 including an adjustable means comprising a disc having a first surface engaged by said springs and a second surface and a set screw threaded in said housing engaging said second surface of said disc.
Claim 6
Dependent Claim
56 words
The pressure responsive device of claim 4 including a reset switch comprising a movable switch arm electrically connected to said stationary contact, a fixed contact arm electrically connected to the fixed end of said movable contact blade and a reset button engageable with said movable switch arm to cause it to engage said fixed contact arm.
Claim 7
Dependent Claim
39 words
The pressure responsive device of claim 2 wherein said second end of said plunger is provided with a reduced diameter portion, said second spring encompasses said reduced diameter portion and said first spring is mounted above said second spring.
Claim 8
Dependent Claim
46 words
The pressure responsive device of claim 6 including a cap-shaped disc interposed between said first and second springs and wherein one end of said second spring bears against said cap-shaped disc and a set screw threaded in said housing engaging a surface of said cap-shaped disc.
Claim 9
Dependent Claim
56 words
The pressure responsive device of claim 7 including a reset switch comprising a movable switch arm electrically connected to said stationary contact, a fixed contact arm electrically connected to the fixed end of said movable contact blade and a rEset button engageable with said movable switch arm to cause it to engage said fixed contact arm.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |