FR2538556A1 - Clip-on ammeter with magnetic circuit opened by a linear movement - Google Patents

Abstract

The magnetic circuit of the instrument, housed in a casing 12, consists of two components 1 and 2. Component 2 is fixed to the casing while component 1 is capable of being given a linear displacement with respect to component 1 so as to open the circuit. The opposite plane faces 3,4; 5,6 of the components 1 and 2 are formed by oblique planar sections intended to come into intimate contact when the magnetic circuit is closed.

Description

The present invention is in the field of pliers

  electric current measurement with magnetic circuit,

  also signed under the name "ampèrermetri- clips

  ques ", which allow you to analyze or measure the

  teristics of electric currents flowing in

  cable or busbar type conductors.

  We know different types of measuring clamps of this kind, for example in the French patent N O

  2,315,696, the Applicant has described a type of pliers which, -

  unlike those of the prior art, in which the magnetic circuit elements are limited in their own movement to the oscillation necessary to ensure a

  good range of magnetic seals, presents an agency-

  in which one or both elements of the magnetic circuit

  tick can during the clamping operation of the conduc-

  electric tor take an infinite number of positions

  its between two extreme positions for a portion of the cir-

  cooked This arrangement with multiple swivel combinations

  gives this device great ease in going to grip

  rer of electrical conductors of difficult or very access

  surrounded by other conductors, bulkheads and the like

  However, pliers of this type do not always give

  days satisfaction that when the joint clamp

  tion is placed around the cable, the dimension ex-

2 2538556

  of the assembly increases, and on the other hand, when the clamp is biased, a reaction occurs

  of the conductor surrounded by the clamp against the ac-

  tion of the spring, therefore of the closing direction of the clamp, which does not ensure an excess M Ient locking

  (or blockage) of the magnetic circuit.

  Furthermore, pliers are known, the cir-

  magnetic baking consists of a fixed part in a general U shape and a mobile part also in a general U shape in opposite direction, whose end faces

  come into close contact under the action of elastic means

  ques, the circuit can be opened manually by means

  a pull tab attached to the movable part so that

  be the lateral penetration of a cable inside the circuit

  baked magnetic Although this new clamp device

  presents some improvement over the available

  sitives of the prior art, approaching the ideal model

  magnetic circuit "horseshoe-air gap", it does not

  no less certain disadvantages especially

  level of guiding precision of the linear moving part

  and planing of extreme surfaces which do not have

  generally did not have close enough contact

  surfaces to avoid loss of magnetic flux.

  An object of the present invention is to

  read an electric current measurement clamp with a magnetic circuit opening by linear movement, which obviates all the aforementioned drawbacks of amperometric clamps

of the prior art.

  A second object of the present invention is to provide a measuring clamp with a very new design

  at the faces of the magnetic circuit, intended to

  in close contact in the closed circuit position.

  Yet another object of the present invention is to provide a clamp for measuring electrical current to

  magnetic circuit opening by linear movement and

3,

  before being easily inserted at the level of available casings

  placed in places difficult to access and / or surrounded by other elements which prevent the easy introduction of ammeter clamps of the prior art, The electric current measuring clamp with magnetic circuit opening by movement linear according to the invention, comprises a magnetic circuit mounted on an insulating housing made up of two elements, one of which is

  fixed while the other is likely to be moved se-

  lon a linear movement with respect to the fixed element of

  so as to open the circuit laterally, this measuring clamp

  sour comprising components of the ma-

  genetics including planar oblique sections of which

  the respective slope angle is determined so that the

  said flat faces come into close contact when

closing of the magnetic circuit.

  In a preferred embodiment of the invention,

  vention, the two components of the magnetic circuit

  tick consist respectively of two sensitive bars

  clearly parallel to each other and comprising respective

  vement at their ends of the bent areas ending in the oblique planar faces of connection of the magnetic circuit; the moving element moves with a certain

  lateral play inside a solid guide sleeve

  re of the clamp frame; the moving element of the magnetic circuit

  tick is guided inside the guide sleeve by guide spacers; the movable element is soilicity in the closed position of the magnetic circuit by elastic means, while maneuvering means are provided to allow to exert a force opposite to that of the elastic means and thus to open the circuit; adjustment means are provided for, in cooperation with the lateral play of the movable element: inside the sleeve, adjust the linear displacement of the movable element in order to

  make the closest possible contact between the fac-

  these end of the bent areas, thus obtaining an iron-

  effective measurement of the magnetic circuit of the clamp; the two contiguous elements of the magnetic circuit carry 253855 d 4, each one a winding, the respective windings being coupled

serial.

  Other features and benefits of the pin-

  this ammeter according to the invention will appear on reading

  ture of the following description of an embodiment

  not limiting, with reference to the accompanying drawings, in which: FIG. 1 is a side elevation view

  partially in section of the -lin- current clamp

  vention, taken from the long side of the shoemaker, the latter being removed and the magnetic circuit closed; Figure 2 is a partially cutaway view of the pliers of Figure lprise of the small c Sté bootmaker;

  Figure 3 is a view of the amperometric clamp

  as analogous to that of figure 1 but with its circuit

magnetic open -

  The current clamp of the invention comprises

  a magnetic circuit consisting of a mobile element 1 my-

  sliding tee inside the housing 12 of the current clamp and guided by means of guide spacers

  12 a, 12 b and a fixed element 2 secured to the housing 12.

  Elements 1 and 2 are substantially the same length, are either of rectangular shape or of revolution,

  and are arranged substantially parallel to each other

  tre In the respective end zones of elements 1 and 2, bent zones 7 are provided respectively,

  8; 9, l O 0, respectively having at their ends li-

  bres of the plane faces 3, 4; 5, 6, obliquely directed

  relative to the cross section of the bent areas respectively

  tives at suitable slope angles so that when the magnetic circuit is closed, as shown in FIG. 1, the oblique faces of the bent zones come

in close contact.

  The magnetic circuit 1, 2 is closed

  seized by elastic means, for example a spring

  compression 13, which urges the movable element 1 in posi-

  closing by taking support on the one hand on the area

  angled 8 and on the other hand for the underside of the bot-

  , tier 12 The magnetic circuit is opened, for example by means of a pull tab 14, secured to the movable element 1 and capable of moving against

  the action of the spring 13 in a light 15 formed longitu-

  '' in a wall 11 of the housing 12, in which

  element 1 slides This light 15 having a long

  sufficient heat to allow proper opening

  of the magnetic circuit, as shown in Figure 3.

  During the unlocking movement of the magnetic circuit, the movement of the mobile element 1 is limited by the lower lip of the slot 15, against which abuts

the pull tab 14.

  The mobile 1 and fixed 2 elements of the am-

  each carry a winding, the respective windings -S 16 a, 16 b being connected in series, the conductor

  16 c connecting them being provided long enough to allow

  be for element 1 to carry out its sliding movement

  opening without hindrance or breaking the circuit Each bo-

  hoeing 16 a, 16 b is also connected to respective terminals

  ves 18 a, 18 b provided on the underside of the boot 12 Oblique bearing faces 3, 4; 5, 6 have relatively small slope angles relative to the cross section of the corresponding bent zones 7, 8; 9, so as to obtain a breakdown of the forces of

  recall of the elastic means 13, very favorable to the effi-

  efficiency of closing the magnetic circuit.

  Adjustment means 17 are also provided which cooperate laterally with the movable element 1 and the guide stops 12 a, 12 b inside the housing,

  so as to allow adjustment or compensation for variations

  machining of the constituent elements 1, 2 of the magnetic circuit, as well as imperfections which may result from

  the use of the current clamp at the end of a circle

  tain fqncti Qnment These adjustment means are

  advantageously constituted by a needle screw 17, vis-

  placed in a threaded through hole in a wall 11 of the

  chon 12 and coming into contact with a side wall of the movable element 1, so as to orient the movable element 1 along a preferred linear path allowing close contacting of the junction faces 3, 5 and 4,6

of the magnetic circuit.

  The current clamp of the present invention can be used in the following manner: first, open the magnetic circuit by

  applying a force on the operating means 14

  citing the movable element 1 in the direction of opening of the magnetic circuit, against the action of the means

  elastic return 13, thus defining in the cir-

  baked magnetic a side opening for the passage of

  conductor crossed by a current which we want to determine

  the electrical characteristics, after which we relate

  che the force applied to the operating means 14 and the magnetic circuit closes under the action of elastic return means 13 which urge the movable element 1 in the locked position of the magnetic circuit against

  the fixed element 2 We can then proceed to the determin-

tions desired.

  It is clear that the external crowding,

  minimizes elements or branches 1, 2 of the magnetic circuit allows a better approach of the conductors

  to measure as well as the slide of element 1 per-

  opens a side window through which the conduc-

  can be easily introduced inside the

  magnetic circuit which will close by self-translation

  blocking under the action of elastic return means 13. It will be readily understood that the needle screw 17 serves on the one hand as a reaction point for applying the faces 3 and 4 of the movable circuit element 1 against the corresponding faces 5 and 6 of the fixed circuit element 2 under the effect of the force decomposition of the spring 13 and on the other hand of means for adjusting the respective height of the mobile circuit element relative to

  the fixed circuit element, the movable element having

  dance to go up higher when the screw 17 is loose-

  This provision allows not only to have a

7 2538556

  good bearing force of the oblique faces against each other but also to make the bearing faces coincide exactly between them and thus to avoid losses of magnetic flux at the level of the external faces of the elements of the magnetic circuit, For reasons ease of use during opening, it will be understood that it is preferable that the -section of the magnetic circuit in its outer branch (faces 3 and 5) must be as close as possible to the upper bent part of the mobile circuit element, and preferably just at the elbow

7 of the movable element 1.

  The invention is in no way limited to the form

  described above, but that it includes all

  are modifications within the reach of ordinary skill in the art

from the same basic principle.

8.

Claims (1)

CLAIMS 1 Electric current measuring clamp with magnetic circuit opening by linear movement, in which the magnetic circuit housed in a housing consists of two elements, one of which is fixed to said housing, while the other is capable of being moved in a linear movement relative to the first element so as to open the circuit, characterized in that the facing planar faces (3, 4; 5, 6) of the elements (1, 2) constituting of the magnetic circuit are formed by oblique sections coming into close contact when the magnetic circuit is closed. 2, measuring clamp according to claim 1, characterized in that the elements (1, 2) consist of two substantially parallel bars, having respectively bent areas (7, 8; 9, 10) each ending with the corresponding oblique flat connection face (3, 4; 5, 6) of the magnetic circuit. 3 measuring clamp according to claim 1, characterized in that the movable element (1) moves linearly while remaining substantially parallel to the fixed element (2), 4 measuring clamp according to the Claim 1, characterized in that the movable element (1) moves, with a certain lateral clearance limited by guide stops (12 a, 12 b) inside the boot (12). Measuring clamp 'according to any one of Claims 1 to 4, characterized in that the mobile element (1) is biased in the closed position of the magnetic circuit by elastic return means (13) and that means de-jpnceuyxe (14) are provided to exert a force opposite to that of the elastic meansg to allow the lateral opening of the magnetic circuit, 6 Measuring clamp according to one of Claims 1 to 5, characterized in that adjustment means (17) are provided to come in cooperation with the movable element (1) inside the case (12) to adjust the q. linear movement of the movable element (1). 7 measuring clamp according to one of claims   1 to 6, characterized in that the two elements (1, 2) constitute   of the magnetic circuit are shaped to receive   see a winding. 8 Forceps of mes ure according to claim 5,   characterized by the fact that the elastic means of   pel of the movable element (1) in the closed position of the magnetic circuit are constituted by a spring   compression taking support on the one hand on the lower zone   re (8) of the movable element and on the other hand on the face bottom of the boot maker (12).   g Measuring clamp according to claim 5, characterized in that the means for operating the mobile element (1) consist of a pull tab (14)   moving in a light (15) provided on a side face   housing rale (12) o Measuring clamp according to any one of   Claims 2 to 9, characterized in that the cross-section of   the upper range of the magnetic circuit is provided up to   te at the upper elbow (7) of the movable element.