US3610852A - Pressure contact switch - Google Patents

Pressure contact switch Download PDF

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Publication number
US3610852A
US3610852A US56360A US3610852DA US3610852A US 3610852 A US3610852 A US 3610852A US 56360 A US56360 A US 56360A US 3610852D A US3610852D A US 3610852DA US 3610852 A US3610852 A US 3610852A
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US
United States
Prior art keywords
slide
piston
pressure
contact
locking
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
US56360A
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English (en)
Inventor
Daniel Lejeune
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.)
Compagnie Generale des Etablissements Michelin SCA
Original Assignee
Compagnie Generale des Etablissements Michelin SCA
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Publication date
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Publication of US3610852A publication Critical patent/US3610852A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K15/00—Check valves
    • F16K15/20—Check valves specially designed for inflatable bodies, e.g. tyres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L17/00—Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies
    • 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

Definitions

  • a pressure contact switch for monitoring the inflation pressure of tires comprises a piston subjected on one side to the pressure of the air in the tire and on the other side [54] Z%? N SWITCH to the force of an opposing calibrated spring.
  • a rod coaxial rawmg with the piston is formed with an inclined cam surface to push [52] US.
  • the rod 200/ 83 J, 340/58 is also formed with a guide and stop for a locking slide capable [51] Int. Cl 1101b /24 of sliding in a second bore having an axis perpendicular to that [501' Field of Search ZOO/61.25, of the first bore.
  • the two slides are urged at all times by 82 D, 83 J 340/58 springs in directions towards the intersection of the two bores.
  • This invention relates to pressure contact switches: i.e., devices that monitor the pressure of a fluid in a sealed enclosure and effect the closing and/or opening of an electrical circuit when the pressure drops below and/or rises above predetermined values. It relates more particularly to novel and highly effective pressure contact switches intended to monitor the inflation pressure of tires.
  • a first condition that should be satisfied is to effect a closing of the electrical circuit that is both rapid and irreversible as soon as the release pressure has been reached and as long as an acceptable pressure is not reestablished.
  • Most of the known devices are of progressive, continuous and reversible operation, resulting in the risk of the fonnation of sparks by the approach to each other of contact pieces as a result of accidental slight variations in pressure.
  • a second condition to be satisfied is to achieve completely automatic action, not requiring any outside intervention to return the pressure contact switch into operating condition after release, other than the reinflation of the tire.
  • Theengagement pressure must be definitely different from the release pressure and independent of it.
  • a third condition to be satisfied is to make the device invulnerable to any excess pressure. This condition is not satisfied in apparatus containing bimetallic strips or flexible interrupters which are always liable of suffering permanent deformation.
  • a fourth condition to be satisfied is the miniaturizing of the device.
  • This miniaturizing is necessary not only in order to take into account the small amount of space available to house a pressure contact switch on an automobile wheel but also for operating reasons.
  • the apparatus must operate both on a stationary vehicle and on a vehicle traveling at high speed, and do so with the same preadjusted release pressure. It is therefore advisable that the pressure contact switch be composed of parts that are at the same time very light, very small and subject to very small displacements, in order to reduce to a minimum friction and the influence of centrifugal force and other forces of inertia.
  • a fifth condition to be satisfied is simplicity of construction, on the one hand, and of operation, on the other hand. This is important not only for reasons of economy-anything which is unnecessarily complex is unnecessarily costly-but also for reasons of utilization, particularly ease of adjustment of the release pressure and ease of positioning with due consideration of the external forces that are to be neutralized.
  • An object of the present invention is to remedy the shortcomings of conventional pressure contact switches and to provide a pressure contact switch that satisfies all of the conditions noted above.
  • the pressure contact switch in accordance with the invention comprises a piston subjected on one side to the pressure of the fluid to be monitored and on the other side to the pressure of a calibrated opposing spring.
  • the switch is characterized in that it further comprises, connected to the piston, a coaxial rod shaped in such a manner as to form, on the one hand, a cam means to push a contacting slide capable of sliding in a first bore and, on the other hand, a guide and a stop for a locking slide capable of sliding in a second bore the axis of which is perpendicular to that of the first bore, the two slides being pushed permanently by springs in the direction towards the intersection of the axes of the two bores.
  • the operation of the device is very simple.
  • the piston moves and, driving along the profiled rod, permits the latter, by means of the inclined cocking surface or cam, to push back the contacting slide, which permits the locking slide to extend into the space common to the two perpendicular bores and to block the contacting slide.
  • the pressure of the fluid drops so that the forces exerted on the piston by the fluid becomes less than that exerted on the piston by the calibrated spring, a movement in the opposite direction of the piston and of the profiled rod commences.
  • the locking slide is carried along and as soon as it emerges from the space common to the two bores, causes a sudden unblocking of the contact slide and the sudden closing of the electrical circuit.
  • the device in question can easily be miniaturized, the different parts having dimensions of the order of a centimeter or millimeter and the displacements of parts being of the order of a millimeter or even of a tenth of a millimeter.
  • FIGS. 1 and 2 are sections through a pressure contact switch in accordance with the invention along a plane contain ing the two axes X-X and Y-Y' of the two bores, FIG. 1 showing the apparatus in the open position of the circuit and FIG. 2 in closed position.
  • the figures show a pressure contact switch I screwed by means of a thread 2 on a connection 3 the end of which intended to be connected to a source of inflation fluid (not shown) is closed by a cap 4. At the opposite end this connection has a nut 5 by means of which the pressure contact switch is connected to the valve of the tire (not shown).
  • the pressure contact switch has a housing 10 of electrically nonconductive material that has the general shape of a body of revolution around the axis X-X' having a cylindrical lateral appendage of axis Y-Y'. Bore holes of different diameters are formed about axes X-X' and YY'.
  • a piston 11 which slides in the bore 12.
  • a diaphragm 13 is hermetically fastened on the piston by a crimped washer 14. This diaphragm, whose periphery is compressed between a washer l5 and a shoulder 16 of the connection 3, assures tightness and makes it possible to transmit to the piston 11 the force due to the pressure prevailing in the connection 3.
  • the piston 11 is subjected to the opposing action of a calibrated spring 36 housed in the bore 17 and resting against a shoulder 18 of the housing and the groove 19 of the piston.
  • a rod 20 which comprises, in succession, a threaded end 21 for membly to the piston 11, a cylindrical portion 22, a shoulder or abutment means 23, a cylindrical-conical inclined cam surface 24 and finally, at its end, a slot 25 to permit screwing by means of a screwdriver.
  • This screwing makes it possible to adjust the pressure at which the pressure contact switch operates.
  • the rod 20 bears on the housing via the bore 26 which is closed by a protective cap 27.
  • a locking slide 30 which abuts the shoulder 23 and is held away from the piston 11 by a spring 31 resting against a shoulder 32, on the slide 30 and a shoulder 33 on the piston 11.
  • the diameter of this slide is less than the diameter of the bore 34 provided in the housing 10.
  • the housing 10 also contains a metal contacting slide 40 housed in a bore 41 of axis- Y-Y' perpendicular to the axis X-X.
  • the contacting slide 40 has a protruding point 44 formed, for instance, of an embedded ball capable of bearing against a portion of the cylindrical-conical inclined cam surface 24.
  • the slide is hollowed in the form of a cup and has a collar 42 capable of coming into contact with a metal washer 45.
  • the slide 40 is pushed in the direction of the rod 20 by a spring 46.
  • the bore 47 which forms an extension of the bore 41 is closed by a metal cap 50 connected by a thread 51 to the housing 10. This cap 50 is of cup shape and comes into contact with the metal washer 45.
  • the thimble 52 has two metal faces 66 and 67 on either side of an insulating layer 68. Each metal face of the thimble 52 is connected by a conductive wire (not shown) to an input terminal of an electrical assembly (also not shown) intended to transmit or process the signal given by the pressure contact. In this way, the driver of an automotive vehicle can be alerted to the fact of low air pressure in a tire of the vehicle.
  • the release pressure that is to say, the pressure at which the locking slide 30 moves away to permit passage of the contactor 40.
  • the stroke of the rod 20 may be limited to l or 2 mm., thus considerably reducing the friction to be overcome, Furthennore, the different parts of this pressure contact switch can be very small, the housing 10 not exceeding 1 to 2 cm. in its largest dimension.
  • the release pressure can be defined with great precision (defined within 0.05 bar) and remains constant for a very wide range of speed of the vehicle, even when the pressure contact switch is fastened to the valve of the tire, that is to say, near the rim, where centrifugal forces are greatest.
  • connection 3 there are provided in the connection 3 on opposite sides of the orifice 70 (FIG. 1) two diaphragm valves 71A and 718.
  • Each of these diaphragm valves comprises a moving part 72 which, depending on its position with respect to its support 73, partially closes or completely frees the passage for the air.
  • the two valves 71A and 71B are arranged in opposition so that whatever the direction of flow of the air, one of them is full open, while the other forms a restricted air passage.
  • the valve 71A located between the orifice 70 and the nut for attachment to the valve of the tire has the function during the inflation of the tire of slowing down the entrance of air. This makes it possible to increase the action of the air on the membrane 13 and tofacilitate the movement of the inclined cocking surface 24. The result is that one can cock the pressure contact switch by using a source of air of lower pressure.
  • the flap 718 located between the orifice 70 and the valve cap 4 has the function of slowing down the emergence of air when the apparatus is connected to a pressure gauge in order to measure the inflation pressure.
  • a pressure gauge in order to measure the inflation pressure.
  • a pressure contact switch for monitoring the pressure of a fluid comprising a movable piston, means transmitting to the piston a force due to a pressure of a fluid to be monitored, an opposing calibrated spring bearing on the piston and urging the piston in a direction opposite to the direction in which the piston is urged by the monitored fluid under pressure, rod means connected to the piston and movable therewith, the rod means being formed with a cam surface and abutment means, a contact slide movable between an alarm position and a standby position, biasing means urging the contact slide towards the alarm position locking slide means moving between a locking position wherein it holds the contact slide in the standby position and a retracted position wherein it permits the contact slide to drop into the alann position, and biasing means urging the locking slide means towards the locking position, the abutment means being engageable with the locking slide means, whereby the cam surface moves the contact slide away from the alarm position and the locking slide means holds the contact slide in the standby position so long as the pressure of the
  • a pressure contact switch according to claim I further comprising a housing formed with two bores having mutually perpendicular axes, the contact slide being movable in one of the bores and the locking slide means being movable in the other, and the biasing means for the contact slide and the biasing means for the locking slide means respectively urging the contact slide and the locking slide means towards the intersection of the two bores.
  • a pressure contact switch according to claim 1 further comprising at least one valve means limiting the rate of flow of fluid acting on the piston.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Measuring Fluid Pressure (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
US56360A 1969-07-21 1970-07-20 Pressure contact switch Expired - Lifetime US3610852A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR6924849A FR2053872A5 (enrdf_load_stackoverflow) 1969-07-21 1969-07-21

Publications (1)

Publication Number Publication Date
US3610852A true US3610852A (en) 1971-10-05

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ID=9037807

Family Applications (1)

Application Number Title Priority Date Filing Date
US56360A Expired - Lifetime US3610852A (en) 1969-07-21 1970-07-20 Pressure contact switch

Country Status (9)

Country Link
US (1) US3610852A (enrdf_load_stackoverflow)
JP (1) JPS4920130B1 (enrdf_load_stackoverflow)
BE (1) BE752642A (enrdf_load_stackoverflow)
ES (1) ES382011A1 (enrdf_load_stackoverflow)
FR (1) FR2053872A5 (enrdf_load_stackoverflow)
GB (1) GB1321873A (enrdf_load_stackoverflow)
LU (1) LU61370A1 (enrdf_load_stackoverflow)
NL (1) NL145090B (enrdf_load_stackoverflow)
SE (1) SE355259B (enrdf_load_stackoverflow)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3872268A (en) * 1973-01-10 1975-03-18 Kanto Seiki Co Tire pressure detecting switch
US4317971A (en) * 1980-05-27 1982-03-02 Rk Industries Adjustable pressure and vacuum limit switch valve
US7161476B2 (en) 2000-07-26 2007-01-09 Bridgestone Firestone North American Tire, Llc Electronic tire management system
US8266465B2 (en) 2000-07-26 2012-09-11 Bridgestone Americas Tire Operation, LLC System for conserving battery life in a battery operated device
WO2017071457A1 (zh) * 2015-10-26 2017-05-04 佛山市美的清湖净水设备有限公司 逆止高压开关及具有其的净水器
CN109334066A (zh) * 2018-11-23 2019-02-15 天津赛象科技股份有限公司 带有缩回检测装置的钢丝圈预置器
EP3984787A4 (en) * 2019-06-11 2023-07-05 Hamaton Automotive Technology Co., Ltd. MULTIFUNCTIONAL EXTERNAL INFLATION VALVE AND ASSEMBLY PROCEDURE FOR AN INFLATION VALVE
CN119340146A (zh) * 2024-12-23 2025-01-21 沈阳华德海泰电器有限公司 紧凑型三工位双断口隔离接地开关

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2638888A1 (fr) * 1988-11-09 1990-05-11 Crouzet Sa Dispositif perfectionne de commutation electrique
CN112192998A (zh) * 2020-10-22 2021-01-08 青岛科技大学 一种智能胎压调节系统

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2296411A (en) * 1941-03-15 1942-09-22 John W Wills Fluid pressure indicator
US3536874A (en) * 1966-10-12 1970-10-27 Weatherhead Co Dual braking system safety device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2296411A (en) * 1941-03-15 1942-09-22 John W Wills Fluid pressure indicator
US3536874A (en) * 1966-10-12 1970-10-27 Weatherhead Co Dual braking system safety device

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3872268A (en) * 1973-01-10 1975-03-18 Kanto Seiki Co Tire pressure detecting switch
US4317971A (en) * 1980-05-27 1982-03-02 Rk Industries Adjustable pressure and vacuum limit switch valve
US7161476B2 (en) 2000-07-26 2007-01-09 Bridgestone Firestone North American Tire, Llc Electronic tire management system
US8151127B2 (en) 2000-07-26 2012-04-03 Bridgestone Americas Tire Operations, Llc System for conserving battery life in a battery operated device
US8266465B2 (en) 2000-07-26 2012-09-11 Bridgestone Americas Tire Operation, LLC System for conserving battery life in a battery operated device
WO2017071457A1 (zh) * 2015-10-26 2017-05-04 佛山市美的清湖净水设备有限公司 逆止高压开关及具有其的净水器
CN109334066A (zh) * 2018-11-23 2019-02-15 天津赛象科技股份有限公司 带有缩回检测装置的钢丝圈预置器
CN109334066B (zh) * 2018-11-23 2023-11-28 天津赛象科技股份有限公司 带有缩回检测装置的钢丝圈预置器
EP3984787A4 (en) * 2019-06-11 2023-07-05 Hamaton Automotive Technology Co., Ltd. MULTIFUNCTIONAL EXTERNAL INFLATION VALVE AND ASSEMBLY PROCEDURE FOR AN INFLATION VALVE
CN119340146A (zh) * 2024-12-23 2025-01-21 沈阳华德海泰电器有限公司 紧凑型三工位双断口隔离接地开关

Also Published As

Publication number Publication date
ES382011A1 (es) 1972-10-16
FR2053872A5 (enrdf_load_stackoverflow) 1971-04-16
NL145090B (nl) 1975-02-17
NL7010379A (enrdf_load_stackoverflow) 1971-01-25
DE2035456B2 (de) 1972-07-20
JPS4920130B1 (enrdf_load_stackoverflow) 1974-05-22
LU61370A1 (enrdf_load_stackoverflow) 1971-07-13
GB1321873A (en) 1973-07-04
BE752642A (fr) 1970-12-29
DE2035456A1 (de) 1971-02-04
SE355259B (enrdf_load_stackoverflow) 1973-04-09

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