FR2479457A1 - PROBE FOR THE CONTROL OF LIQUIDS - Google Patents

Abstract

A.SONDE FOR THE CONTROL OF LIQUIDS. B. SOUND CHARACTERIZED IN THAT IT INCLUDES A CASE WITH AT LEAST ONE PIERCING, AN ELECTRODE WRAPPED WITH A SOFT INSULATING AND FLEXIBLE TUBE AND IN THAT FLEXIBLE PADDING RINGS 10, 11 ARE ARRANGED BETWEEN THE SEALING SHOULDERS 3 , 5 AND THE SOFT INSULATING TUBE 6. C. THE INVENTION RELATES TO A PROBE FOR THE CONTROL OF LIQUIDS.

Description

1 * - 2479457

  The invention relates to a probe for the control of liquids, provided with a casing having at least

  a positioning bore and at least one electrode

  It is composed of a flexible flexible insulating tube, the electrode and the loop each comprising two sections of different diameters.

  as well as an axial sealing shoulder covering the space-

  corresponding to this difference in diameter, the electrode with its tubular casing passing longitudinally through the pergage, and the flexible insulating tube being sealed tightly

  between the two sealing shoulders.

  An essential advantage of probes of this kind (US Pat. No. 3,339,411) is that they can use as insulating jacket for the electrode a material

  in the usual flexible tube on the market; because we have the possibility

  to make insulating envelopes particularly

  economic in any length necessary.

  However, it has been found that insulating flexible tubes, especially when they consist of a

  flexible material made of plastic material, for example

  trafluoroethylene, crack, in the embedding zone between the sealing shoulders, in case of changes

  frequent tempering. We are then assured neither of an isola-

  impeccable electrode against the probe housing, or a tightness between these two

elements.

  The present invention aims to achieve

  be a probe - of the type indicated in the preamble - thanks to which, even during temperature changes, the necessary electrical insulation as well as the tightness between the electrode

  and the probe housing are always assured.

  To this end, the invention relates to a probe for the control of liquids which is characterized in that

  flexible packing rings are arranged between the shoulder-

  sealing elements and the flexible insulating tube.

  Thanks to the coating of the flexible tube between the flexible packing rings in the embedding zone,

  the thermal expansion and retraction of this tube

  Temperature changes can be made sufficiently, so that excessive plastic stresses are not exerted on the insulating flexible tube. Consequently

  the tightness of this tube is no longer threatened by changes in

temperatures.

  / We will indicate in the following modes of

  advantageous embodiment of the invention.

  This is how the packing rings

  may consist of a material

  the same thermal expansion as the insulating flexible tube. In this way, relative displacements of expansion between the flexible insulating tube and the packing rings at the location of the common contact surfaces are avoided. As a result, the flexible tube, which is sensitive

  to the tensions of material, undergoes only very weak.

  The packing rings may even be advantageously constituted by the same material as the

flexible insulating tube.

  The invention will be better understood using

  of the following description and the accompanying drawing

  an exemplary embodiment of the invention.

  - The single figure of this drawing is a sectional view along the probe according to the invention, by a plane passing through its axis, showing the insertion mode of the rings.

packing.

  In a probe housing 1 is provided a positioning bore 2 having a larger diameter section and a smaller diameter section. The difference in diameter between these two sections is covered by an axial sealing shoulder 3 of conical shape. In the bore 2 is housed a rod-shaped electrode 4 which, in accordance with the bore 2, also comprises a larger diameter section and a smaller diameter section as well.

  that, connecting these two sections together, a shoulder of

  axial slenderness 5, of conical shape also.

  An insulating flexible tube 6, flexible,

  polytetrafluoroethylene material, wraps the electro-

  of 4 at least for part of its length. Under the action of a spring 7 as well as via a clamping nut 8 and an electrically insulating pressure ring 9, the flexible tube 6 is sealed in the

  area of the two sealing shoulders 3, 5.

  Between the sealing shoulder 3 and the

'2479457

  insulating flexible tube 6 as well as between the latter and the sealing shoulder 5, in both cases a ring of

  flexible packing 10, 11 made of polytetrafluoroethylene. The étan-

  pressure resistance, between the boltier 1 of the probe and the electrode 49 is ensured accordingly via

  two packing rings 10, 11 and the flexible tube 6.

  The packing rings 10, 11 can

  without difficulty being dimensioned to any thickness.

  On the other hand, the flexible insulating tube has a relatively thin wall, among others, to enable it to be introduced by one of its ends, without any problem, into the diameter of the longer section.

thin electrode.

  Thanks to the flexible packing rings

  , 11 the necessary conditions are established to ensure

  and sufficiently free retraction and retraction of the flexible tube 6 in the embedding zone, only critical, during temperature changes. The differences that occur in the thermal expansion of the flexible tube 6 and the casing 1 of the probe or the electrode 4 are compensated by the rings 10, 11 dimensioned accordingly, under these conditions it does not occur at the inside the tube 6 high voltages that could lead to cracks in the material; we are therefore always assured of impeccable sealing and perfect electrical insulation between the

housing 1 and the electrode 4.

Claims (3)

  1.- Probe for the control of liquids,   provided with a casing having at least one position drilling   and at least one electrode wrapped with a flexible insulating flexible tube, the electrode and the bore each having two sections of different diameters and an axial sealing shoulder covering the spacing corresponding to this difference in diameter, the electrode with its jacket-tube passing longitudinally through the bore, and the flexible insulating tube being sealed between the two sealing shoulders, characterized in that flexible packing rings (10, 11) are arranged between the sealing shoulders (3, 5) and the flexible insulating tube (6). 2. Probe according to claim 1, characterized in that the packing rings (10, 11) consist of a material having substantially the same   specific thermal expansion as the flexible insulating tube (6).   3.- Probe according to one or the other   1 and 2, characterized in that the rings of   packing (10, 11) are made of the same material as the flexible insulating tube (6).