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US3816685A - Pressure responsive device having improved means for calibration - Google Patents

Pressure responsive device having improved means for calibration Download PDF

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Publication number
US3816685A
US3816685A US00317905A US31790572A US3816685A US 3816685 A US3816685 A US 3816685A US 00317905 A US00317905 A US 00317905A US 31790572 A US31790572 A US 31790572A US 3816685 A US3816685 A US 3816685A
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US
United States
Prior art keywords
diaphragm
calibration
configuration
pressure
portions
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00317905A
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English (en)
Inventor
P Fiore
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Texas Instruments Inc
Original Assignee
Texas Instruments Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Texas Instruments Inc filed Critical Texas Instruments Inc
Priority to US00317905A priority Critical patent/US3816685A/en
Priority to GB4419873A priority patent/GB1449855A/en
Priority to IT52691/73A priority patent/IT994403B/it
Priority to NLAANVRAGE7313243,A priority patent/NL175116C/xx
Priority to JP11134373A priority patent/JPS576771B2/ja
Priority to DE2360609A priority patent/DE2360609C2/de
Priority to FR7345293A priority patent/FR2211715B1/fr
Application granted granted Critical
Publication of US3816685A publication Critical patent/US3816685A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H35/00—Switches operated by change of a physical condition
    • H01H35/24—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow
    • H01H35/34—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow actuated by diaphragm
    • H01H35/343—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow actuated by diaphragm by snap acting diaphragm
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H35/00—Switches operated by change of a physical condition
    • H01H35/24—Switches operated by change of fluid pressure, by fluid pressure waves, or by change of fluid flow
    • H01H35/26—Details
    • H01H35/2607—Means for adjustment of "ON" or "OFF" operating pressure
    • H01H35/2614—Means for adjustment of "ON" or "OFF" operating pressure by varying the bias on the pressure sensitive element

Definitions

  • a pressure responsive device comprises a first chamber having a port sealed from a second chamber by a pressure responsive snap acting diaphragm. At pressures above an actuation pressure the diaphragm snaps from a first configuration to a second opposite configuration causing a motion transfer pin to move and actuate an electrical switch. The diaphragm snaps back to the first configuration when pressure decreases to a deactuation pressure, different than the actuation pressure, thereby permitting deactuation of the switch.
  • a special diaphragm support is provided to enable calibration of both the actuation and the deactuation pressure independently of one another.
  • BACKGROUND OF THE INVENTION Devices are known for opening and closing an electrical circuit or an electrical switch in response to changes in values of pressure by admitting pressure to one side of a snap acting diaphragm causing it to snap from a first configuration to a second configuration at a predetermined value of pressure or actuation pressure and return at another value of pressure or deactuation pressure.
  • the difference between'these values of pressure is called the pressure differential of the diaphragm of the device.
  • the force required to deform the calibration-stop member is substantially greater than any forces to which the diaphragm will be subjected during operation as a pressure responsive device. While both of these approaches are effective a problem exists when it is desired to adjustboth the actuation and deactuation pressures. That is adjustment of the slope of the outer peripheral edge of the diaphragm tends to affect the position of the calibration-stop member and hence the deactuation pressure while adjustment of the calibration-stop member tends to affect the slope of the outer peripheral edge and hence the actuation pressure. Thus in order to obtain specific actuation, deactuation pressures it is frequently necessary for the person calibrating the device to cycle back and forth between the two adjustments and finally to make a judgment adjustment to obtain the required calibration.
  • the instant invention provides a special calibration-stop member having a portion used for adjustment of the actuation pressure, another portion used for adjustment of the deactuation pressure and means to isolate the two portions from each other.
  • the improved calibration stop member comprises a relatively rigid annular flange joined to a variable cone center portion by an isolation land and groove which serve as a stress concentrator.
  • an improved pressure responsive device in which the actuation and deactuation pressures can be independently adjusted.
  • Another provision is the provision of a pressure responsive device which is less' expensive to produce than prior art de-' vices having the same calibration tolerances, a device which can be readily produced on a high volume basis, one which can be easily calibrated by automated processes and one which is reliable and has a long usable life.
  • FIG. 1 is a front cross section taken through the center of a pressure responsive device made in accordance with the invention.
  • FIG. 2 is a front cross section taken through the center of an alternate calibration-stop member useful in the FIG. I embodiment.
  • numeral 10 represents a switch made in accordance with the invention.
  • a housing 12 receives a hub portion 14 which in turn slidingly receives a motion transfer pin 16 in a centrally located bore extending through the hub.
  • Hub 14 is joined to housing 12 by collar member 13 crimped thereto.
  • Members 18 and 20 extend through apertures in bottom wall 22 of housing 12 locking terminals 24, 26 as by staking in electrical connection therewith.
  • Member 18 has a portion 19 extending laterally therefrom into the switch cavity 28 which serves as a stationary contact.
  • Member 18 may be provided with a layer of material having especially high electrical conductivity characteristics such as copper or silver.
  • a movable contact arm 30 formed of an electrically conductive material having good spring characteristics such as beryllium nickel cantilever mounted to member 20 in any convenient manner by riveting at 32.
  • Contact 34 is mounted on the free distal end and is adapted to move into and out of engagement with portion 19 in response to the position of pin 16.
  • a snap acting disc 36 either monometallic or multimetallic is positioned adjacent an end of pin 16 and is adapted to change from the configuration shown in FIG. 1 to an over center configuration in which it biases pin 16 downwardly and with it movable arm 30 thereby opening the circuit through terminals 24, 26.
  • Disc 36 is supported on calibration member 38 and is sandwiched between member 38 and cover 40.
  • these members and collar 13 are sealed at their marginal periphery as by heliarc welding along their periphery as indicated at 42. It will be understood that other means may be employed to seal the diaphragm member from the pressure chamber as by clamping.
  • Port fitting 44 is provided with boss 46 which is received in a mating aperture in cover 40 and has a bore 48 therein for reception of pressure (or vacuum). Also shown is an adjusting screw 50 also having a longitudinally extending bore 52 and a spring seat 54 for reception of spring 56 which extends from the spring seat 54 to disc 36. Spring 56 and adjusting screw 50 are optional and may be used if it is desirable to narrow the pressure differential.
  • Housing 58 has an annular seat 60 which receives the outer peripheral portion 64 of cover 40, disc 38, member 38 and collar 13. Housing 58 is provided with apertures 66, 68 for reception therethrough of insulated wires 70, 72 which are connected respectively to terminals 24, 26 in any suitable manner as by crimping. Housing 58 is then back filled with suitable electrically a insulative material such as potting material 59.
  • Calibration-stop member 38 comprises a first annular outer portion 74, a second annular inner cone portion 76 and joined thereto by land 78 formed with a groove 80 therebetween which acts as an isolation means. Land 78 extends intermediate the bottom surface of outer portion 74 and the junction with inner portion 76. Bore 77 is provided in member 38 to permit pin 16 to pass therethrough.
  • Member 38 is formed of a material such as AISI type 304 Stainless Steel and is hydrogen annealed after forming to a Rockwell superficial hardness of (15-T) 73-90. This permits permanent deformation of member 38 as desired. It should be noted that for member 38 to function as intended no portion of 76 can be above the level of portion 74.
  • the device may be assembled by first forming a subassembly by welding together cover 40, diaphragm 36, calibration-stop member 38 and collar 13.
  • the actuation pressure rating can be adjusted by permanently deforming the outer periphery margin of member 38 by using an appropriate tool, until the slope of the outer peripheral margin of diaphragm 36 is such that the diaphragm snaps at the desired actuation pressure.
  • the deactuation pressure rating can be adjusted by introducing through cover 40 sufficient pressure to deform portion 76 of member 38 changing the angle of this conical portion to the desired amount when the diaphragm will snap back to its original configuration at the desired deactuation pressure.
  • portion 76 is such that a pressure substantially above any operating pressures to which the device will be subjected to in use as a switch is required to deform the portion. Due to the existence of groove 80 and land 78 the stresses created upon deformation of portion 76 are concentrated in land 78 and portion 74 is unaffected by this deformation. Thus each pressure setting can be carefully, accurately and independently adjusted.
  • Another advantage offered by use of the groove is that it standardizes the tangent line of contact between the dished portion of the diaphragm and calibration-stop member. Without the groove the tangent line could vary around the periphery of the diaphragm thereby affecting both pressure settings.
  • FIG. 2 shows an alternate calibration-stop member 82 comprising first outer annular portion 84 joined to second inner annular portion 86 by land 88 formed with isolation groove 90 therebetween. Aperture 92 is provided to permit pin 16 to pass therethrough. Member 82 is particularly useful when it is desirable to provide a narrower pressure differential since portion 86 is virtually on the same level as outer portion 84 prior to calibration-
  • a condition responsive device comprising a circular snap-acting diaphragm having a dished surface movable to and from first and second overcenter configurations;
  • calibration means including a member having first and second portions, and means separating the first and second portions so that the second portion can be deformed without affecting the first portion, the member positioned adjacent a surface of the diaphragm;
  • actuation means positioned adjacent the diaphragm and responsive thereto, the actuation means in contact with the diaphragm when the diaphragm is in the first configuration and out of contact with the diaphragm when the diaphragm is in the second configuration.
  • a device in which the first portion of the member is a relatively stiff annular flange, the second portion of the member is a relatively thin flange, and the means separating the two portions from each other includes an isolation groove defined in the member between the portions.
  • a condition responsive assembly comprising a generally circular diaphragm deformed into a dished shape to render it snap acting from a first configuration to a second opposite configuration upon the occurrence of the condition
  • a calibration-stop member comprising a first relatively rigid annular flange portion, the periphery of the diaphragm and the flange being generally coincident and attached to one another, the member having a second relatively flexible portion extending radially inwardly from the flange portion, and means separating the first and second portions so that the second portion can be deformed without affecting the first portion.
  • An assembly according to claim 4 further including a first chamber formed on the side of the diaphragm remote from the calibration stop-member, a port formed in the first chamber to permit ingress and egress of a fluid medium, and means mounted adjacent the diaphragm on the side of the diaphragm opposite the first chamber responsive to the snapping of the diaphragm from one configuration to the other upon the occurrence of a predetermined pressure in the first chamber.
  • the means responsive to the snapping of the diaphragm from one configuration to the other includes an electric switch comprising a base member having an open end, a stationary contact and a movable contact arm disposed in the base, the movable arm adapted to move into and out of engagement with the stationary contact, a hub having a bore extending therethrough closing the open end of the base, an aperture provided in the calibration-stop member and a motion transfer pin slidably received in the bore of the hub extending from the movable contact arm through the aperture in the calibration-stop member to a point adjacent the diaphragm so that in one configuration of the diaphragm the movable contact arm is separated from the stationary contact.
  • An assembly according to claim 6 in which two electrical leads extend from the electrical switch, a casing is disposed about the electrical switch and is provided with two apertures through which the leads extend, and electrically insulative potting material fills the space between the casing and the switch and leads.
  • An assembly according to claim 7 including a port fitting positioned in the port of the first chamber, the fitting having a threaded bore, a tubular threaded member adjustably positioned in the bore of the fitting and a coil spring extending between the tubular threaded member and the diaphragm.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
  • Measuring Fluid Pressure (AREA)
US00317905A 1972-12-26 1972-12-26 Pressure responsive device having improved means for calibration Expired - Lifetime US3816685A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US00317905A US3816685A (en) 1972-12-26 1972-12-26 Pressure responsive device having improved means for calibration
GB4419873A GB1449855A (en) 1972-12-26 1973-09-20 Condition responsive device having means for calibration
IT52691/73A IT994403B (it) 1972-12-26 1973-09-21 Perfezionamento negli interruttori sensibili alla pressione
NLAANVRAGE7313243,A NL175116C (nl) 1972-12-26 1973-09-26 Op druk reagerende elektrische schakelaar.
JP11134373A JPS576771B2 (it) 1972-12-26 1973-10-03
DE2360609A DE2360609C2 (de) 1972-12-26 1973-12-05 Auf Druckänderungen ansprechende Vorrichtung, insbesondere Druckschaltgerät
FR7345293A FR2211715B1 (it) 1972-12-26 1973-12-18

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00317905A US3816685A (en) 1972-12-26 1972-12-26 Pressure responsive device having improved means for calibration

Publications (1)

Publication Number Publication Date
US3816685A true US3816685A (en) 1974-06-11

Family

ID=23235766

Family Applications (1)

Application Number Title Priority Date Filing Date
US00317905A Expired - Lifetime US3816685A (en) 1972-12-26 1972-12-26 Pressure responsive device having improved means for calibration

Country Status (7)

Country Link
US (1) US3816685A (it)
JP (1) JPS576771B2 (it)
DE (1) DE2360609C2 (it)
FR (1) FR2211715B1 (it)
GB (1) GB1449855A (it)
IT (1) IT994403B (it)
NL (1) NL175116C (it)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4091249A (en) * 1976-10-06 1978-05-23 Emerson Electric Co. Pressure sensitive electrical switch having a snap element
US4169390A (en) * 1978-03-20 1979-10-02 Allen-Bradley Company Adjusting mechanism for a snap-acting Belleville washer
US4219710A (en) * 1976-04-15 1980-08-26 Stop Alert Corporation Pressure change responsive sensor and related vacuum operable switch assembly
US4243858A (en) * 1979-01-19 1981-01-06 Therm-O-Disc Incorporated Snap disc operated pressure switch
US4296287A (en) * 1979-11-23 1981-10-20 Texas Instruments Incorporated Weatherproofed condition responsive switch
US4633579A (en) * 1984-11-19 1987-01-06 Texas Instruments Incorporated Method for making a pressure responsive switch
US4667069A (en) * 1985-08-16 1987-05-19 Ranco Incorporated Multiple disc pressure responsive control device
AU579668B2 (en) * 1984-11-05 1988-12-01 Ranco Incorporated Pressure control device and method of making the same
US4851627A (en) * 1984-10-02 1989-07-25 Omron Tateisi Electronics Co. Compact pressure sensitive switch for use in detecting fluid pressure changes
US4939321A (en) * 1988-05-11 1990-07-03 Fuji Koji Manufacturing Co., Ltd. Pressure switch with laminated diaphragm
US4947674A (en) * 1988-09-07 1990-08-14 Commonwealth Edison Limit switch calibration system
US5198631A (en) * 1991-09-11 1993-03-30 General Electric Company Pressure responsive control device
US5304758A (en) * 1992-04-30 1994-04-19 Bendix Atlantic Inflator Company Temperature compensated low pressure switch for hybrid inflators
US5482439A (en) * 1995-01-09 1996-01-09 Chen; Chi-Wen Power breaker for a compressor for automobiles with a curved plug and wrinkled control disk
US5808255A (en) * 1996-07-22 1998-09-15 Texas Instruments Incorporated Fluid pressure responsive electric switch
US20100300863A1 (en) * 2007-05-29 2010-12-02 Norgren Gmbh Pressure switch with an integrated diaphragm and switch
CN101976632A (zh) * 2010-11-05 2011-02-16 如皋市易之生电子元件有限公司 一种膜片式微型压力开关
CN102683105A (zh) * 2011-02-04 2012-09-19 森萨塔科技公司 流体压力响应式电开关
CN105118732A (zh) * 2015-09-02 2015-12-02 上海埃而生电气有限公司 压力开关斜面防水结构

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2703283C2 (de) * 1976-02-03 1984-09-06 Smiths Industries Public Ltd. Co., London Druckempfindliches Diaphragma
GB2005474B (en) * 1977-09-29 1982-04-07 Texas Instruments Inc Condition responsive devices
JPS5811844U (ja) * 1981-07-17 1983-01-25 株式会社ボッシュオートモーティブ　システム 圧力スイツチ
EP0764960B1 (en) * 1995-09-19 2004-08-18 Texas Instruments Incorporated Fluid pressure responsive electric switch and method for assembling same
FR2810377B1 (fr) * 2000-06-14 2002-12-06 Lacroix Soc E Dispositif de commande a commutation brusque, et dispositif pyrotechnique de decoupe d'une verriere d'aeronef ou analogue comportant un tel dispositif de commande

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3378656A (en) * 1966-01-03 1968-04-16 Texas Instruments Inc Adjustment means for electrical switch
US3528455A (en) * 1966-11-16 1970-09-15 Robertshaw Controls Co Condition responsive parameter control means
US3584168A (en) * 1968-12-30 1971-06-08 Texas Instruments Inc Fluid pressure operated diaphragm switch with improved means and method for calibration
US3676620A (en) * 1970-11-18 1972-07-11 Edward E Modes Adjustable pressure responsive transducer
US3793885A (en) * 1972-09-05 1974-02-26 Rosemount Inc Diaphrgam construction for differential pressure transducer
FR2223581B1 (it) * 1973-03-30 1976-09-24 Schlumberger Compteurs

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4219710A (en) * 1976-04-15 1980-08-26 Stop Alert Corporation Pressure change responsive sensor and related vacuum operable switch assembly
US4091249A (en) * 1976-10-06 1978-05-23 Emerson Electric Co. Pressure sensitive electrical switch having a snap element
US4169390A (en) * 1978-03-20 1979-10-02 Allen-Bradley Company Adjusting mechanism for a snap-acting Belleville washer
US4243858A (en) * 1979-01-19 1981-01-06 Therm-O-Disc Incorporated Snap disc operated pressure switch
US4296287A (en) * 1979-11-23 1981-10-20 Texas Instruments Incorporated Weatherproofed condition responsive switch
US4851627A (en) * 1984-10-02 1989-07-25 Omron Tateisi Electronics Co. Compact pressure sensitive switch for use in detecting fluid pressure changes
AU579668B2 (en) * 1984-11-05 1988-12-01 Ranco Incorporated Pressure control device and method of making the same
US4633579A (en) * 1984-11-19 1987-01-06 Texas Instruments Incorporated Method for making a pressure responsive switch
US4667069A (en) * 1985-08-16 1987-05-19 Ranco Incorporated Multiple disc pressure responsive control device
US4939321A (en) * 1988-05-11 1990-07-03 Fuji Koji Manufacturing Co., Ltd. Pressure switch with laminated diaphragm
US4947674A (en) * 1988-09-07 1990-08-14 Commonwealth Edison Limit switch calibration system
US5300741A (en) * 1991-09-11 1994-04-05 General Electric Company Pressure responsive control device
US5198631A (en) * 1991-09-11 1993-03-30 General Electric Company Pressure responsive control device
US5524333A (en) * 1991-09-11 1996-06-11 General Electric Company Method of assembling a pressure responsive control device
US5304758A (en) * 1992-04-30 1994-04-19 Bendix Atlantic Inflator Company Temperature compensated low pressure switch for hybrid inflators
US5482439A (en) * 1995-01-09 1996-01-09 Chen; Chi-Wen Power breaker for a compressor for automobiles with a curved plug and wrinkled control disk
US5808255A (en) * 1996-07-22 1998-09-15 Texas Instruments Incorporated Fluid pressure responsive electric switch
US5870817A (en) * 1996-07-22 1999-02-16 Texas Instruments Incorporated Fluid pressure responsive electric switch and method for assembling same
US20100300863A1 (en) * 2007-05-29 2010-12-02 Norgren Gmbh Pressure switch with an integrated diaphragm and switch
US8173918B2 (en) * 2007-05-29 2012-05-08 Norgren Gmbh Pressure switch with an integrated diaphragm and switch
CN101976632A (zh) * 2010-11-05 2011-02-16 如皋市易之生电子元件有限公司 一种膜片式微型压力开关
CN102683105A (zh) * 2011-02-04 2012-09-19 森萨塔科技公司 流体压力响应式电开关
CN102683105B (zh) * 2011-02-04 2016-01-27 森萨塔科技公司 流体压力响应式电开关
CN105118732A (zh) * 2015-09-02 2015-12-02 上海埃而生电气有限公司 压力开关斜面防水结构

Also Published As

Publication number Publication date
DE2360609C2 (de) 1983-11-03
FR2211715B1 (it) 1976-11-19
IT994403B (it) 1975-10-20
NL175116B (nl) 1984-04-16
GB1449855A (en) 1976-09-15
NL175116C (nl) 1984-09-17
DE2360609A1 (de) 1974-06-27
FR2211715A1 (it) 1974-07-19
JPS576771B2 (it) 1982-02-06
NL7313243A (it) 1974-06-28
JPS4996275A (it) 1974-09-12

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