US3761958A - Pressure switch - Google Patents

Pressure switch Download PDF

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Publication number
US3761958A
US3761958A US00332728A US3761958DA US3761958A US 3761958 A US3761958 A US 3761958A US 00332728 A US00332728 A US 00332728A US 3761958D A US3761958D A US 3761958DA US 3761958 A US3761958 A US 3761958A
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US
United States
Prior art keywords
pressure chamber
yoke
pressure switch
switch according
magnetro
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
US00332728A
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English (en)
Inventor
S Nishira
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.)
Denki Onkyo Co Ltd
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Denki Onkyo Co Ltd
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Filing date
Publication date
Application filed by Denki Onkyo Co Ltd filed Critical Denki Onkyo Co Ltd
Application granted granted Critical
Publication of US3761958A publication Critical patent/US3761958A/en
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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/56—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function the record carrier having reserve loop, e.g. to minimise inertia during acceleration measuring or control in connection therewith
    • G11B15/58—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function the record carrier having reserve loop, e.g. to minimise inertia during acceleration measuring or control in connection therewith with vacuum column
    • 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
    • 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
    • H01H35/2621—Means for adjustment of "ON" or "OFF" operating pressure by varying the bias on the pressure sensitive element the bias being magnetic

Definitions

  • a pressure switch comprising a housing having an internal cavity which is divided into a high pressure [52] 338/36 73/398 2; chamber and a low pressure chamber by a flexible dia- 51 1 Cl H0 phragm, a moving yoke which forms part of a magnetic 1 T 1c 3/ path and moves in accordance with a motion of the said [58] Field of Search 338/32 R.
  • the present invention relates to a pressure switch which operates with a pressure difference of a flowing substance such as, for example, a gas.
  • the present invention provides a contactless pressure switch free from the said disadvantages.
  • the pressure switch in accordance with the present invention comprises a housing made of a non-magnetic material having an internal cavity, a flexible diaphragm which divides the said internal cavity into a high pressure chamber and a low pressure chamber and moves so as to vary the capacities of the two chambers relatively in accordance with a difference in pressures of the said both chambers, a high pressure side port provided at the said housing to lead to the said high pres sure chamber, a low pressure side port provided at the housing to lead to the said low pressure chamber, a non-magnetic moving member provided at one side of the said flexible diaphragm, for example, the side facing the low pressure chamber so that the said moving member moves in accordance with movement of the said flexible diaphragm, guides provided on the said housing to guide the said moving member, a magnetic path containing a moving yoke made of a magnetic material which is fixed on the said moving member, a galvano-magnetro effect device such as, for example, a magnetro-resistance
  • FIG. la is a cross sectional plan view of the pressure switch of the present invention.
  • FIG. lb is a cross sectional front view of the said switch, 1
  • FIG. 2 is a circuit diagram showing an embodiment of a switching circuit to be employed in the pressure switch in accordance with the present invention.
  • FIG. 3 is a partly magnified sectional view of the pressure switch as seen along line 1-1 in FIG. la,
  • FIG. 4 is a rough plan view illustrating another embodiment of the magnetic path to be employed in the pressure switch in accordance with the present invention.
  • FIG. 5 is a cross sectional view illustrating another embodiment of the pressure switch of the present invention.
  • FIG. 6 is a sketch showing an application example of the pressure switch of the present invention.
  • FIGS. la to 1b there is shown an embodiment of the pressure switch in accordance with the present invention.
  • Housing 1 is made up by fitting non-magnetic disc type cover 12 to open end 11b of non-magnetic cylindrical body 11 having bottom 11a and has internal cavity 13.
  • the housing is also provided with low pressure side port 14 at its bottom 11a and disc cover 12 is provided with high pressure side port 15.
  • Stepped part llc is provided on the internal circumferential surface of cylindrical body 11, and O ring 2 made of an elastic material such as, for example, a rubber and periphery 3a of disc type flexible diaphragm 3 made of an flexible material such as, for example, rubber are held between the said stepped part and disc cover 12.
  • the said O ring is depressed by a plurality of bolts 4 fixing disc cover 12 on the said cylindrical body to maintain cavity 13 air-tight.
  • the said flexible diaphragm air-tightly divides cavity 13 into high pressure chamber 13a leading to high pressure side port 15 and low pressure chamber 13b leading to low pressure side port 14 and is designed to be deflected in accordance with a varying difference in pressures in high pressure chamber 13a and low pressure chamber 13b, thus varying the capacities of both chambers.
  • Moving member 5 made of a non-magnetic material is attached to one surface 3b facing the low pressure chamber of flexible diaphragm 3.
  • Moving member 5 is constructed so that it moves in accordance with movement of flexible diaphragm 3 while being guided by guides 16 provided on housing Guides 16 are comprised of a pair of grooves 16a and 16a which are provided on the internal surface of the said cylindrical body to opposed each other in parallel to the axial direction of the cylindrical body and both ends 5a and 5a of moving member 5 are slidably fitted into the said grooves respectively. Moreover, projected center part 5b of moving member 5 is contacted with the said surface 3b of flexible diaphragm 3.
  • a resetting means such as, for example, coil spring 6 which pushes up the said moving member toward high pressure chamber 13a, that is, provides a resetting force to cause flexible diaphragm 3 to be deflected toward high pressure chamber 13a is provided between moving member 5 and bottom 11a of cylindrical body 11.
  • Bar type moving yoke 7 made of a magnetic material and magnetized with N and S polarities at its both ends 7a, 7a is fixed on moving member so that the said moving yoke intersects at a right angle to the moving direction of moving member 5.
  • Fixed yoke 8 in combination with moving yoke 7 forms a magnetic path. It is made of a magnetic material in the U-shape and is fixed inside cylindrical body 11 so that its both ends 8a and 8a are opposed to both ends 7a and 7a of the said moving yoke.
  • a pair of galvano-magnetro effect devices 9 and 9' are arranged along the moving direction of moving yoke 7, that is, the moving direction of moving member 5, on the surface of one end 8a of fixed yoke 8 opposed to end 7a of the moving yoke.
  • the galvano-magnetro effect devices can be the semiconductor devices of which electrical characteristic varies in accordance with variation of the intensity of the magnetic field which acts on the devices.
  • the semiconductor devices can be the magnetro-resistance effect device or Hall effect device made of indium antimony or indium arsenic.
  • One galvano-magnetro effect device 9 is located at a position where it is opposed to moving yoke 7 when there is no difference in the pressures in high pressure chamber 130 and low pressure chamber 13b, and other galvano-magnetro effect device 9 at a position where it is opposed to moving yoke 7 when the moving yoke moves in accordance with the difference in the pressures in both chambers.
  • Printed circuit board is provided on a line extended from end part 8a of said fixed yoke 8 and switching circuit S is formed on this printed circuit board.
  • switching circuit S which performs switching operation according to the change in electrical characteristic according to variation of the intensity of the magnetic field which acts on galvano-magnetro effect devices 9 and 9'.
  • Resistor S2 and magnetro-resistance effect devices 9 and 9 are series-connected with power supply E across the positive and negative polarities, resistor S3 is connected across the connecting point between resistor S2 and the magnetro-resistance effect device and the negative polarity of power supply E, and the intermediate connecting point between both magnetro-resistance effect devices is connected to the base of transistor S1. Accordingly, the potential at the said intermediate connecting point is the potential at the base of transistor S1. Furthermore, the collector of transistor 81 is connected to the positive polarity of power supply E through collector resistor S4 and the emitter of the said transistor is connected to the negative polarity of power supply E. Output terminals S5 and S5 are provided at the collector and emitter.
  • moving yoke 7 is opposed to one galvano-magnetro effect device 9 when the pressures in high pressure chamber 13a and low pressure chamber 13b are equal and accordingly the magnetic flux is applied to device 9.
  • the magnetic flux is not applied to other galvano-magnetro effect device 9'. Accordingly, the internal resistance value of device 9 is large and that of device 9' is small.
  • the specified voltage is applied across both ends of the devices which are connected in series. Therefore, the base potential of transistor S1 is so low that transistor S1 is in the on-state and the potential at the collector is high. Thus, the voltage across both output terminals S5 and S5 is large.
  • the internal resistance of device 9' suddenly increases with application of the magnetic flux to the said device and the internal resistance of device 9 suddenly decreases without application of the magnetic flux to the said device. Accordingly, the potential at the intermediate connecting point between the said both devices rises to result in the rise of the potential at the base of transistor S1. With this potential rise, transistor S1 is in the on-state and the collector potential lowers, that is, the voltage across both output terminals S5 and S5 becomes low.
  • the said switching device thus performs the switching operation in response to the pressure difference between the high and low pressure chambers.
  • FIG. 4 there is shown a fixed yoke having a magnet.
  • moving yoke 7 and fixed yoke 8 form a magnetic path
  • moving yoke 7 need not always be magnetized
  • fixed yoke 8 can be comprised of magnet M and magnetic yoke pieces 81 and 81' extended from both poles N and S of the said magnet and moving yoke 7 can be made of a magnetic material which is not magnetized.
  • flexible diaphragm 3 provided with moving member 5 at surface 3c of the high pressure chamber side.
  • disc cover 12' is provided with low pressure side port 14 and bottom 11a of cylindrical body 11 is provided with high pressure side port 15.
  • Low pressure chamber 13b is formed between flexible diaphragm 3 and said disc cover 12' and high pressure chamber 13a between flexible diaphragm 3 and bottom 11a of the cylindrical body 11.
  • Low pressure side surface 3b of flexible diaphragm 3 is provided with dish-type support member 61 and coil spring 6 is arranged between the said support member and disc cover 12.
  • Moving member 5 provided at high pressure side surface 30 of flexible diaphragm 3 is fixed to support member 61 with screw 51 which passes through flexible diaphragm 3.
  • guides 16, moving yoke 7, fixed yoke 8 and galvano-magnetro effect devices 9 and 9' are constructed as shown in the embodiment of FIG. lb.
  • FIG. 6 there is shown an application of the pressure switch in accordance with the present invention.
  • Case C is designed so that opening C is formed to be open upwardly, exhaust port C is provided at the lower end and the air is exhausted by vacuum pump P through the said exhaust port. Furthermore, case C is provided with a plurality of detection ports C;, with specified intervals along a vertical direction. These detection ports C are respectively led to low pressure side ports 14 of pressure switches SW through air duct pipes Pl. High pres sure side port 15 of each pressure switch is opened in the atmosphere.
  • Extended part T between two reels R and R is inserted from opening C of case C, and when vacuum pump P is actuated, extended part T of the tape is pulled to the maximum to the lower part of case C. There occurs a difference of pressures in the spaces at both sides of the tape as the border.
  • the pressure in the upper side of the tape is equal to the atmospheric pressure and the pressure in the lower side is lower than the atmospheric pressure.
  • the pressure switches connected to the detection ports at the lower side of the tape operates with the difference of pressures in the high and low pressure chambers. On the contrary, the pressure switches connected to the detection ports at the upper side of the tape do not operate since there is no difference of pressures in the high and low pressure chambers.
  • the pressure switches operate in accordance with the lowering position of the tape and therefore the lowering position of the tape can be detected by the corresponding pressure switch. Accordingly, a fixed delivery allowance of the tape can be maintained at all times by controlling the rotation rate of tape feed reel R with actuation of the pressure switch.
  • the pressure switch in accordance with the present invention can be employed as the control switch for various pressureapplied system such as the air pressure control switch of machine tools. 1
  • the pressure switch has the following advantages as compared with the conventional switches.
  • the condition for the switching operation can be set as desired by setting the conditions of the switching circuit.
  • the pressure necessary for the switching operation can be freely selected by properly selecting the thickness of the flexible diaphragm and the material.
  • the operating point of the pressure switch can be I easily changed by setting the position of the galvanomagnetro effect device.
  • the pressure switch in accordance with the present invention finds a wide range of applications in many various fields.
  • a pressure switch comprising:
  • a housing made of a non-magnetic material having an internal cavity
  • b. a flexible diaphragm which divides said cavity into a high pressure chamber and low pressure chamber and causes the capacities of said both chambers to vary relatively
  • a low pressure side port which is provided in said housing so as to lead to said low pressure chamber
  • a moving member made of a non-magnetic material which is provided on one of high pressure and low pressure chamber side surfaces of said flexible diaphragm so that said moving member moves in accordance with displacement of said flexible diaphragm
  • a magnetic path comprised of a magnetic moving yoke which is fixed on said moving member
  • a switching circuit which is provided with a switching device and is connected to said galvanomagnetro effect device and performs the switching operation in accordance with actuation of said galvano-magnetro effect device, wherein the intensity of magnetic flux to be applied to said galvono-magnetro effect device through said magnetic path varies in accordance with movement of said moving yoke.
  • a pressure switch according to claim 1 wherein a printed circuit board is provided inside said housing and said printed circuit board is formed with said switching circuit.
  • a pressure switch according to claim 1, wherein said magnetic path is comprised of said moving yoke and a magnetic fixing yoke fixed inside said housing, the fixed yoke opposes to both end faces in parallel with the moving direction of the moving yoke, and one of the fixed yoke and moving yoke contains a magnet.
  • a pressure switch according to claim'l, wherein a resetting means is provided which depresses said flexible diaphragm so that said flexible diaphragm deflects towards said high pressure chamber when there is no difference of pressure between the high pressure chamber and the low pressure chamber and which has a resetting force against displacement of said flexible diaphragm causing the capacity of said high pressure chamber to increase.

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  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
US00332728A 1972-02-18 1973-02-15 Pressure switch Expired - Lifetime US3761958A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1972020167U JPS5128616Y2 (enrdf_load_stackoverflow) 1972-02-18 1972-02-18

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4006402A (en) * 1974-05-22 1977-02-01 Societe Internationale De Mecanique Industrielle, S.A. Device for remote transmitting pressure signals
WO1981000274A1 (en) * 1979-07-26 1981-02-05 Vapor Corp Contactless pressure sensitive switch
US4254395A (en) * 1979-12-26 1981-03-03 Robert Bosch Gmbh Electromechanical force converter for measuring gas pressure
US4340877A (en) * 1979-11-17 1982-07-20 Robert Bosch Gmbh Hall generator pressure transducer
FR2521815A1 (fr) * 1982-02-12 1983-08-19 Truetzschler & Co Manocontacteur electronique utilisable en particulier comme organe de mesure et de commande sensible aux variations de pression dans des machines textiles
US4658644A (en) * 1984-10-05 1987-04-21 Dieter Coesfeld Manometer device for continuous monitoring of the air pressure in vehicle tires
US4710744A (en) * 1985-04-08 1987-12-01 Honeywell Inc. Pressure transducer package
US4821011A (en) * 1986-03-24 1989-04-11 Aisin Seiki Kabushiki Kaisha Pressure sensor
US5024294A (en) * 1990-06-07 1991-06-18 Johnson Service Company Differential pressure transducer

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2515867A (en) * 1945-12-19 1950-07-18 Fuller Reginald Cyril Electrical means for operating fluid pressure indicating gauges and signaling devices
US3136970A (en) * 1963-01-18 1964-06-09 Int Resistance Co Pressure transducer
US3366909A (en) * 1965-05-31 1968-01-30 Siemens Ag Contact-free electrical signal device
US3571774A (en) * 1966-09-24 1971-03-23 Raimund Finsterholzl Elektrote Non-contacting electronic switch gear
US3681735A (en) * 1969-10-25 1972-08-01 Noboru Masuda Push-button type switching apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2515867A (en) * 1945-12-19 1950-07-18 Fuller Reginald Cyril Electrical means for operating fluid pressure indicating gauges and signaling devices
US3136970A (en) * 1963-01-18 1964-06-09 Int Resistance Co Pressure transducer
US3366909A (en) * 1965-05-31 1968-01-30 Siemens Ag Contact-free electrical signal device
US3571774A (en) * 1966-09-24 1971-03-23 Raimund Finsterholzl Elektrote Non-contacting electronic switch gear
US3681735A (en) * 1969-10-25 1972-08-01 Noboru Masuda Push-button type switching apparatus

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4006402A (en) * 1974-05-22 1977-02-01 Societe Internationale De Mecanique Industrielle, S.A. Device for remote transmitting pressure signals
WO1981000274A1 (en) * 1979-07-26 1981-02-05 Vapor Corp Contactless pressure sensitive switch
US4340877A (en) * 1979-11-17 1982-07-20 Robert Bosch Gmbh Hall generator pressure transducer
US4254395A (en) * 1979-12-26 1981-03-03 Robert Bosch Gmbh Electromechanical force converter for measuring gas pressure
FR2521815A1 (fr) * 1982-02-12 1983-08-19 Truetzschler & Co Manocontacteur electronique utilisable en particulier comme organe de mesure et de commande sensible aux variations de pression dans des machines textiles
DE3204881A1 (de) * 1982-02-12 1983-08-25 Trützschler GmbH & Co KG, 4050 Mönchengladbach Elektronischer druckschalter, insbesondere als messglied fuer die erfassung von druckschwankungen in textilmaschinen
US4562358A (en) * 1982-02-12 1985-12-31 Trutzschler Gmbh & Co. Kg Electronic pressure responsive switch
US4658644A (en) * 1984-10-05 1987-04-21 Dieter Coesfeld Manometer device for continuous monitoring of the air pressure in vehicle tires
US4710744A (en) * 1985-04-08 1987-12-01 Honeywell Inc. Pressure transducer package
US4821011A (en) * 1986-03-24 1989-04-11 Aisin Seiki Kabushiki Kaisha Pressure sensor
US5024294A (en) * 1990-06-07 1991-06-18 Johnson Service Company Differential pressure transducer

Also Published As

Publication number Publication date
JPS5128616Y2 (enrdf_load_stackoverflow) 1976-07-19
JPS4896457U (enrdf_load_stackoverflow) 1973-11-16

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