FR2628888A1 - IMPROVED HIGH PRESSURE CONTACTOR - Google Patents

Abstract

The present invention relates to a pressure sensitive electrical contactor of the type comprising a contact module 100 provided with at least one movable electrical contact 150 and a control module 200 actuated by a pressurized fluid and provided with a return member which controls the movements of the moving contact. The movable contact is formed of an elastic blade 150 of electrically conductive material which also constitutes the return member of the control module 200.

Description

(FRENCH REPUBLIC) Publication no .: 2,628,888 {use only

  for NATIONAL INSTITUTE reproduction orders)

INDUSTRIAL PROPERTY

  D National registration number 88 03532 PARIS

) Int CI ': H 01 H 35/38.

@ A1 PATENT APPLICATION

  Filing date: March 18, 1988. (Applicant (s): JAEGER. - FR.

( Priority

Inventor (s): Georges Dumoulin.

  ) Date of public availability of the

  application: BOPI "Patents" n 38 of September 22, 1989.

  6 References to other national documents appearing

  rented: (t Holder (s): (Agent (s): Cabinet Regimbeau, Martin, Schrimpf,

Warcoin and Ahner.

  (Advanced high pressure switch.

  The present invention relates to an electrical contactor sensitive to pressure of the type comprising a module of, 3 ', t42 contact 100 provided with at least one movable electrical contact / 160 1 WC 1 il ,,, and a control module 200 operated by a fluid t. t;: under pressure and fitted with a return device which controls the "

  movements of the mobile contact. The mobile contact is formed. -

  of an elastic blade 150 of electrically conductive material | -

  which also constitutes the recall element of the module of 1.z, t / - <- .; 'order200. 12 1 12 130 t t50 132 oO 0: cO O0 O0 oe O D Sale of booklets at IMPRIMERIE NATIONALE. 27. rue de la Convention - 75732 PARIS CEDEX 15 l The present invention relates to the field of contactors

  pressure sensitive electrics.

  Many pressure sensitive electrical contactors have already been proposed. These essentially comprise a contact module provided with at least one movable electrical contact and a control module actuated by a pressurized fluid and provided with a return member which controls the movements of the movable contact. The control module generally comprises a membrane subjected to the compression to be checked, a coil return spring which biases the membrane against said pressure and transforms the pressure into displacement, and means associated with the membrane which act on the movable contact of the contact module, when the pressure to be checked exceeds a determined threshold. Conventional electrical contactors of the aforementioned type,

  sensitive to pressure, have already done great service.

  However, they have the following disadvantages.

  On the one hand, the conventional contactors hitherto proposed generally do not withstand pressures greater than 25 bars. Beyond

  from these pressures, the membrane is deteriorated.

  On the other hand, conventional high pressure contactors

  present a non-negligible size.

  The object of the present invention is to eliminate these drawbacks.

  come. The object of the present invention is in particular to propose an electrical contactor suitable for detecting pressures without damage.

  exceeding 100 bars, and tolerate overpressures of 650 bars minimum.

  These aims are achieved within the framework of the present invention by means of an electrical contactor sensitive to pressure of the type known per se comprising a contact module provided with at least one movable electrical contact and a control module actuated by a pressurized fluid. and provided with a return member which controls the movements of the movable contact, characterized according to the invention in that the movable contact is formed of an elastic blade of electrically conductive material which also constitutes the return member of the module ordered. The present invention finds particular, but not exclusively, application in the pressure control of the circuits of

  motor vehicle braking or suspensions.

  Other features, purposes and advantages of this

  invention will appear on reading the detailed description which will

  follow, and with reference to the appended FIG. 1 which represents a view in longitudinal axial section of an electrical contactor conforming to the

present invention.

  The body of the contactor illustrated in the appended figure is referenced 10. It has an axis of symmetry 11. The body 10 defines an internal chamber 12 capable of receiving the contact module 100 which will be

  defined in more detail below, and a control piston ridige 200.

  Room 12 is blind. It opens axially at a first end 13 of the body. However, a cylindrical bore 14 centered on the axis II is formed at the second end 15

  of the body 10 to connect the bottom of the chamber 12 to the outside.

  Bedroom 12 is storied. This means that it does not present

  not a constant section over its entire length.

  Basically, according to the illustration in the appended figure, the chamber 12 is delimited by two cylindrical portions 16, 17,

juxtaposed axially.

  The cylindrical portion 16 of a smaller diameter forms the bottom of the internal chamber 12. It is adjacent to the second end 15 of the body 10. The aforementioned bore 14 opens into this

portion 16.

  The front end 18 adjacent to the first end 13 of the body 10) of the second cylindrical portion 17 of larger diameter is tapped. It receives a ring 110 having a complementary external thread 111. The ring 110 serves to support a washer 120 placed inside the second portion 17 of the chamber 12. The washer 120 itself serves to support a sleeve 130 placed in the cylindrical portion 17, c ' that is to say between the washer 120 and the first portion

cylindrical 16.

  A strip 140 of electrically conductive material passes through the washer 120. The strip 140 extends parallel to the axis 11

  but is off-center with respect to it inside the chamber 12.

  The end 141 of the strip 140, the most internal to the chamber 12, carries

a contact pad 142.

  Preferably, the stud 142 is formed of a screw engaged by

  thread in the strip 140. The axis 143 of the screw 142 extends transversely

  dirty to the axis 11. The engagement by thread of the stud 142 in the strip 140 makes it possible to adjust the radial position of the stud 142. Preferably, the stud 142 is positioned on the strip 140 so

  that its radially innermost point 144 coincides with axis 11.

  The adjustment of the stud 142 on the strip 140 can be operated from the outside after assembly of the contactor, thanks to an opening 19

  formed in the side wall of the body 10, opposite the screw 142.

  An annular recess 20 is formed between the cylindrical portions 16 and 17. The recess 20 is directed towards the

  first end 13 of the body 10.

  The sleeve 130 defines an internal flaring 131 near the recess 20. The internal diameter of the channel 132 defined at the level of the internal flaring is less than the diameter of the first cylindrical portion 16. The internal flaring 131 defines an annular bearing 133 centered on axis 11 and directed towards the bottom of the

  chamber 12, that is to say towards the second end 15 of the body.

  An annular seal 134 rests against the seat

support 133.

  The piston 200 is engaged in the first cylindrical portion 16 of the chamber 12. The piston 200 is formed of a cylindrical body centered on the axis II and having a diameter substantially * equal, while being very slightly less, than the diameter of the first cylindrical portion 16 of the chamber 12. Thus the piston 200 is guided in translation parallel to the axis 11 in the chamber 12. The piston 200

  is provided, substantially at ml-length, with an annular groove 202.

  The latter receives an annular seal 204. The seal 204 preferably has a cross section in X. It rests against the cylindrical portion 16 of the chamber 12 and provides sealing between the piston 200 and the body 10. The piston 200 receives the pressure applied to bore 14 on its surface 206 transverse to axis 11 and directed towards the second

end 15 of the body.

  The pressure applied to bore 14 therefore tends to

  move the piston 200 towards the first end 13 of the body.

  However, the piston 200 is biased towards the. second end 15 of the body by a blade 150. This rests, on the one hand, by a first end 151 on the piston 200 and, on the other hand, by a

  second end 152 on the washer 120.

  More precisely still, preferably, the piston 200 is provided on its second face 208 transverse to the axis II and directed towards the first end 13 of the body, with a slot 209. This is oriented diametrically relative to the axis 11. It has a width substantially equal to the thickness of the blade 150 to receive freely

  the aforementioned end 151 thereof.

  Similarly, the washer 120 is provided on its face 121 directed towards the piston 200, with a slot 122 oriented diametrically relative to the axis 11 and designed to freely receive the second end 152 of

  the blade 150. Preferably, the blade 150 is slightly bent at rest.

  Its mean plane defined at mid-thickness of the ends 151, 152, is

  advantageously intersecting the axis I1.

  The blade 150 is made of an electrically conductive elastic material, with a thermoelastic temperature coefficient close to zero. The blade 150 can be formed for example of an alloy of nickel and chromium, such as the material sold under the name

  "DURINVAL" by METALIMPHY.

  If necessary, the blade 150 may be formed from a blistering blade. It will be noted on examining FIG. I that the contactor further comprises a cap 160 set on the first end 13 of the body 10. The cap 160 carries a connecting blade 161 connected

electrically with the strip 140.

  It will be noted that preferably the stud 142 fixed on the strip

  is placed substantially opposite the center of the blade 150.

  The two electrical contacts of the contact module 1-00 integrated into the contactor shown in the appended figure are formed one by the stud 142 associated with the strip 140, the other by the movable blade 150

  also serving as a reminder.

  The two contactor output terminals, on the other hand, are formed by the blade 161 carried by the cap 160, the other by the

body 10 of the contactor itself.

  A direct electrical connection is defined, for example, by welding or any other equivalent means between the output blade 161 and the

internal slat 140.

  The body 10 of the contactor must be made of an electrically conductive material, preferably metal. The electrical connection between the body 10 and the blade 150 is provided by the piston 200. This must therefore also be made of a material electrically

  conductive, preferably metal.

  On the other hand, a person skilled in the art will easily understand that the washer 120 must not electrically connect the strip 140 and the blade 150. For this, the washer 120 can be formed from electrically insulating material. Alternatively, the strip 140 can pass through the washer

without contact with it.

  The operation of the electrical contactor illustrated on the

attached figure is as follows.

  At rest, when no high pressure is applied to the bore 14, the blade 150 pushes the piston 200 against the bottom of the chamber 12, that is to say towards the second end 15 of the body 10. A first state of electrical connection is thus defined between the pad 142 and the

blade 150.

  According to the embodiment shown in FIG. 1 attached, the blade 150 rests against the stud 142 in the rest position,

  that is to say when no high pressure is applied to bore 14.

  When, on the other hand, the high pressure to be detected is applied to the face 206 of the piston via the bore 14, the piston 200 axially compresses the blade 50 which works in buckling. The deformation in the radial direction of the blade 150 modifies the state of connection between the stud 142 and the blade 150. It will in fact be noted that when the pressure applied to the bore 14 pushes the piston 200 towards the washer, the radius of curvature of the central curved part of the blade 150

tends to decrease.

  As appears on examining the appended figure, according to the illustrated embodiment, during the application of the pressure to be detected on the bore 14, the contact is interrupted between the stud 142 and the blade 150. Such a type contactor is generally called downward contactor, insofar as the electrical contact closes when the pressure applied to bore 14 is less than the pressure

threshold to detect.

  A reverse arrangement can be adopted in the context of the present invention, that is to say that the electrical contactor can constitute an upward contactor, having an electrical contact between the stud 142 and the blade 150 which closes when the pressure

  applied to the bore 14 is greater than the threshold pressure to be detected.

  To do this, simply reverse the curvature of the blade 150.

  In other words, to obtain a downward contact, the concavity of the blade 150 is directed towards the stud 142 as illustrated in FIG. 1. On the other hand to obtain an upward contact, the convexity

  of blade 150 must be directed towards stud 142.

  The nominal winding of the blade 150 which determines the restoring force exerted on the piston 200 can be controlled by axial adjustment of the ring 110 serving to support the washer 120. The pressure setting determining the change of state of the contactor is operated by axial adjustment of this ring 110, in combination with the adjustment in position of the stud 142 on the strip 140. In other words, the washer 120 which serves as a stop linked to the body 10 for the blade 150 is adjustable parallel to

  the direction of movement of the rigid piston.

  It will be noted that the seal 202 ensures the tightness of the contactor, that is to say between the piston 200 urged by the fluid under

  pressure and the body 10, in the normal operating range.

  In the event of overpressure, the piston 200 comes to rest against the annular seal 134 which has - the general shape of a flat washer transverse to the axis II and centered on it. Thus the seal 134 guarantees the tightness of the contactor whatever the pressure applied to the bore 14. Preferably, the seal 134 is glued against the bearing

support 133 of the sleeve 130.

  Of course the present invention is not limited to the particular embodiment which has just been described but extends to

  all variants according to its spirit.

Claims (13)

R E V E N D I C A T I O N S   1. Pressure-sensitive electrical contactor of the type comprising a contact module provided with at least one movable electrical contact and a control module actuated by a pressurized fluid and provided with a return member which controls the movements of the movable contact , characterized in that the movable contact is formed of an elastic blade (150) of electrically conductive material which constitutes   also the recall member of the control module (200).   2. Electric contactor according to claim 1, characterized in that the control module comprises a rigid piston (200) subjected, on the one hand, to the pressure to be checked and stressed,   on the other hand, by the elastic blade (150) serving as a return member.   3. Electrical contactor according to claim 2, characterized in that the rigid piston (200) is guided in translation in the body (10) of the contactor and that the mean plane of the elastic blade (150) extends parallel to the direction of translation of piston (200).   4. Electric contactor according to one of claims I to   3, characterized in that the elastic blade (150) is a blistering blade.   5. Electric contactor according to one of claims I to   4, characterized in that the elastic blade (150) bears, on the one hand, against a rigid piston (200) guided in translation in the body (10) of the contactor and subjected to the pressure to be detected, on the other hand hand, against a   stop (120) linked to the contactor body.   6. Electrical contactor according to claim 5, characterized in that the stop (120) linked to the body (10) de'contactor is adjustable parallel to the direction of movement of the rigid piston (200).   7. Electric contactor according to one of claims 1 to   6, characterized in that it comprises a body (10) defining an internal chamber (12) capable of receiving in translation a piston (200) subjected to the pressure to be detected, in which the internal chamber (12) is stepped to define a bearing surface (133) capable of limiting the movement of the piston (200) in the event of overpressure.   8. Electrical contactor according to claim 7, characterized in that an annular seal (134) is provided on the surface support (133).   9. Electric contactor according to one of claims 7 or   8 taken in combination with one of claims 5 or 6, characterized   by the fact that the bearing surface (133) is defined on a sleeve (130)   which rests against the stop (120) linked to the body (10) of the contactor.   10. Electric contactor according to one of claims 1 to   9, characterized in that the control module comprises a rigid piston (200) subjected to the pressure and that an annular seal (204) is provided   on the periphery of the piston (200).   11. Electric contactor according to claim 10, characterized in that the annular seal (204) provided on the periphery   piston (200) has a cross section in "X".   12. Contactor according to one of claims 1 to 11,   characterized in that the contact module (100) comprises the elastic blade (150) forming mobile electrical contact and a second strip (140) provided with a contact pad (142) placed substantially opposite the center of the elastic blade (150).   13. Electric contactor according to claim 12, characterized in that the contact pad (142) is adjustable transversely to the axis (11) of the body (10) of the contactor relative to the second coverslip (140). 119 143 11 140 142 200 132 O 161I 1415 134 VA 202 151 - 18 / II 152 121 1 301 200 PO2204 132 GB Co Co Co