US3652962A

US3652962A - Switching device with moving parts in the form of a cross

Info

Publication number: US3652962A
Application number: US74741A
Authority: US
Inventors: Roger G Preux
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-29
Filing date: 1970-09-23
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28
Also published as: DE2047070A1; FR2058828A5

Abstract

An electromagnetic switching device having a built-in unit consisting of a cross-shaped magnetic circuit element adapted to selectively cooperate with the poles of at least two magnetic circuits and having at least one contact element which may be driven by the magnetic circuit element towards one of two positions so as to selectively close at least two corresponding electrical circuits.

Description

United States Patent Preux Inventor: Roger G. Preux, 27, rue dEaubonne, St.

Gratien, France Sept. 23, 1970 Filed:

Appl. No.:

Foreign Application Priority Data [4 1 Mar.28,1972

Primary Examiner-Harold Broome Attorney-Waters, Roditi, Schwartz & Nissen Sept. 29, 1969 France ..6933124 ABSTRACT An electromagnetic switching device having a built-in unit US. Cl ..335/203, 335/180 7 consisting of a cross shaped magnetic circuit element adapted Int. Cl. I I to selectively cooperate the poles of at least [wo magnetic Field of Search Y circuits and having at least one contact element which may be 335/229, 234, 203 driven by the magnetic circuit element towards one of two positions so as to selectively close at least two corresponding m A electrical circuits.

6 Claims, 5 Drawing Figures 2.4 X 7 i 1 11 s 8 F 1mg 4' 5i; W l/ 4 :P 11 f z Y i T j/ 3 q; I 92:. 14-? 2 @61 10 B 4 j:- \z/ 44 4/ L l l l\ l PATENTED MAR 2 8 I972 SHEET 1 BF 2 SWITCHING DEVICE WITH MOVING PARTS IN THE FORM OF A CROSS The present invention concerns an electro-mechanic or electro-magnetic switching device with moving parts made up of several elements of different materials and forming a unit in the form of a cross.

Systems of electro-mechanic or electro-magnetic switching are known, such as relays in which the commutation is effected by means of moving parts pivoting around apivot mounted on a bearing. In these relays, the articulation on a level with the pivot must be carefully carried out so that the speed of switching is not excessively reduced by friction. But

in any case the effect of friction cannot be reduced beyond acertain limit. Such a relay is, then, at the same time relatively costly, clumsy and insufficiently rapid of function.

Relays are also known in which the moving parts are constituted essentially of a single element playing the roles of magnetic switching element and contact element. Now, a magnetic switching element must be constructed of a material best suited from the point of view of magnetism, permeability and retentivity, while a contact element must be essentially a good conductor, supple and elastic. In practice, the material constituting the single element is but imperfectly endowed with the set of qualities needed for the switching and for the contact.

The aim of the present invention is to remedy these disadvantages and, to do this, it has as object a switching device with moving parts distinguished in that the moving parts are constituted by a built in unit, freely placed, by at least one of its points and to the exclusion of pivots and hearings, on a support on which it rocks between two switching positions, the said unit comprising at least one magnetic circuit element capable of cooperating selectively with the poles of at least two magnetic circuits and at least one contact element driven by the magnetic element towards one of the two positions in order to close selectively at least two corresponding electrical circuits, the said elements forming together a unit in the form of a cross.

The advantage of such an arrangement is that it does away with the need of a spindle or a rotating pivot for the moving parts; indeed, when the magnetic element is attracted or repelled magnetically, the moving parts are limited in their movement towards the extreme positions only by their two elements appreciably orthogonal which ensure crossed guides. The movement of the moving parts is limited following two perpendicular axes, one relating to the contacts of the electric circuits and the other to the supports for the poles of the magnetic circuit. The absence of pivots results in a great simplification of the construction of the switching device and therefore a notable decrease in its cost price. n the other hand, because the moving parts are constituted of two elements each playing a well-defined role, it becomes possible to construct each of these elements in the material which is best suited to its function. For the magnetic element material will be chosen having the best properties from the point of view of magnetism, permeability and retentivity and for the contact element material which is supple, elastic and a good conductor of electricity.

Thanks to the switching device according to the invention, it becomes equally possible to use for the moving contact nonplated materials ensuring a longer life and a better quality of switching. The suppression of the pivots and bearings allows miniaturization of the moving parts and consequently an increase in the speed of switching. Moreover, the invention is applied to parts which rock, as much around one of their ends as around their centre of gravity or around an intermediate point. It applies also to every system of electro-mechanical or electro-magnetic switching and more especially to relays.

Advantageously, the unit of moving parts of elements of fixed contacts and poles are enclosed in an insulated case. So the switching can take place sheltered from external pollution.

According to one particular method of putting the invention into effect, the magnetic element rests on one extremity in a recess provided on a pole common to the two magnetic circuits whilst the other extremity is attracted alternatively towards the poles of the magnetic circuits, the contact element being driven by this movement, striking alternatively the fixed contacts housed in the insulated case.

Because of this arrangement the position of the moving parts is assured since it is limited, in one direction, by the support of the moving contact on the fixed contacts of the electric circuit and, in the perpendicular direction, by the support of the moving magnetic element on the housing and on the pole of the magnetic circuit. It will be noticed that a fault of position of the moving parts is allowed in the two directions because if there is slipping of the latter, the support of the contacts and the magnetic coupling remain nevertheless ensured in perfect conditions.

On the other hand, the movement of the moving parts following the first direction is determined by the equality of the reactions of the contacts exerted on the corresponding fixed contacts, which implies the equality of these reactions which guarantees identical contact pressures. A result of that is that the moving magnetic element is helped in its change of position by the couple produced by these contact reactions.

It is advantageous that the magnetic circuits are excited selectively by single or double coils fed by reversible direct current. It will be noted in any case that this method of excitation is not limiting.

According to another method of putting the invention into effect, the moving parts are capable of pivoting around the conjunction of the magnetic element and the contact element, the movement of the parts being limited in each switching position by two poles of the magnetic circuit and by two fixed contacts.

The switching device according to the invention is at the same time economical, of simple construction and of assured functioning.

In any case the invention will be better understood referring to the description made with regard to the accompanying drawings, given solely as an example and in no way limiting, and in which:

FIG. 1 is a plan view of a first method of effecting a relay according to the invention, the cover of the case having been removed.

FIG. 2 is a section following line IIII of FIG. 1.

FIG. 3 is a plan view of a second method of effecting a relay according to the invention.

FIG. 4 is a similar view of a third method of effecting the relay according to the invention and FIG. 5 is a perspective view of a fourth method of effecting the relay according to the invention.

FIGS. 1 and 2 represent a relay showing the bases and principles of the invention. The relay comprises essentially a builtin moving switching element, formed by the unit of a magnetic circuit moving element 1 and a supple element 2 consisting of a flexible blade or wire. At the ends of the blade 2 are built up the contact elements 3 and 4. The method of assembling these different elements is not restrictive; they can be fixed by soldering, brazing riveting, by adhesive or by the interplacirig of one or several conducting or insulating parts, the incorporation of several insulating pieces allows, with the help of a similar moving magnetic element, the switching of several separate circuits thanks to the multiplicity of supple elements and of contacts. There will also be seen in the figures a core 5 in which a housing 6 is fitted, having an appropriate shape and serving as articulation joint of the moving parts. A space or diametrical play will be provided dimensionally and axial play between the end of element 1 and the wall of the housing 6.

The magnetic circuit is made up of poles 7 and 8, coils'9 and 10, single or double according to the electrical function to be obtained, a magnet 11, opposite poles l2 and 13 and fixed contacts 14 and 15 for one position of the equipment, 16 and 17 for the other position. In certain cases of application or for reasons of sizing, the fixed contacts 14, l5, l6 and 17 are slightly supple or effected by blades; blade 2 can then be rigid.

As can be seen in FIG. )1, blade 2 is subjected to a reaction couple from the contacts 14 and 15, following the arrows f. This couple is balanced by the magnetic action F of pole 7 and by the reaction R of the support of the housing 6. The position of the moving parts is ensured, following an axis X identical with the axis of the magnet 11, thanks to the support of the blade 2 between the contacts 14 and 15, and following axis Y perpendicular to axis X, thanks to the support of the pole 7 and of the housing of the core 5.

The moving parts, the fixed contact elements and the poles which surround them are located inside an insulated case so that switching can be effected, sheltered from outside pollution. The insulated chamber is made up by the assembly of a piece 18 and two covers upper and lower 19 and 20 visible in FIG. 2. The method of assembling is not restrictive; they can be stuck, soldered, sealed, crimped or closed mechanically. The covers constitute the basic parts receiving the fixed contacts as well as

walls

21 and 22 limiting laterally the moving parts. As shown in FIG. 2, the fixed contacts are made up of elements built up by soldering on the output pins, which allows easy manufacture of the covers, without impairing the contacts, and which limits the contact materials to very small dimensions thus encouraging a reduction in construction costs.

When working, in the position represented in FIG. 1, the moving magnetic element 1 is coupled to the magnetic circuit made up of the pieces 1, 7, ll, 12 and the cores of the coils. If the coils 9 and 10 are actuated so as to polarise the extremity of pole 7 with a polarity identical to that produced by the magnet and opposed to that of the extremity of pole 8, element 1 will be repelled by pole 7 and attracted by pole 8; the relay will then have switched another circuit. This change of position can be produced, according to suitable dimensions, by the momentary or permanent action of the excitation. It is the method of bistable working assuring the memory of the excitations. In the case where a monostable working is desired, it would be well to suppress one of the couplings, for example element 12 or element 13 and to actuate the coils in an appropriate way.

Such a relay offers multiple advantages among which may be quoted notably:

The simplification of the construction of the relay particularly because of the absence of pivots and bearings; the moving parts, on the other hand, may or may not comprise seperate contacts 3 and 4;

The use for the magnetic element 1 of a material which is best and solely suited for the magnetic functions and its permeability; it is the same for the moving switching element which serves only the function of support and can consequently be chosen to fulfil best these conditions; in the same way, contacts 3 and 4 will be adapted to the sole function of switching;

The possibility of using for the moving contact non-plated materials, which leads to a longer life and better quality of switching;

The miniaturization of the moving parts and consequently the rapid movement of the parts between the two switching positions;

The natural balance of contact pressures in the switched circuit; the movement of the moving parts following axis X, for example, is determined by the equality of efforts on contacts 14 and H5;

The certainty of having a correct coupling of the magnetic pieces and identical contact pressures. A fault of position of contacts I4 and E5 is permitted by movement following axis X of the mobile part; in the same way a fault in position of pole 7 or of the housing 6 is permitted by movement of the moving parts following axis Y. This fault of position is transformed into a reciprocal slipping but the support of the contacts and the coupling remain assured;

The possibility of enclosing the contacts and the moving parts in an insulated case because of the small dimensions of the moving parts;

The simplification of construction of the supple contacts and The use of the reaction of the contact support as an additional force, at the time of change of position of the magnetic element 1; as soon as an opposition of field is produced by one of the windings, the magnetic element 1 switches and is helped in its change of position by the couple produced by the reactions f of the contacts.

The family of relays thus produced can work following different methods of excitation, according to the functional properties of the invention and the needs of industrialization.

FIG. 3 represents a second method of producing a relay constructed according to the principles of the invention. The relay comprises a ferrite rod 25,

opposite poles

26 and 27, a coil whose core 28 serves as articulation for the moving magnetic element 29 integral with a moving contact element. This latter rocks between fixed contacts 311, 32 and 33, 34 inside an insulated case 35.

FIG. 4 represents a lay-out in which the moving element in form of a cross is made up of a magnet or a ferrite rod 40 and a supple contact element. This part is capable of rocking between fixed

contacts

42, 44 and 43, 45. The extremities of the

cores

48 and 49 of

coils

46 and 67 make up the poles on which the magnetic element 410 rests.

FIG. 5 represents another method of production in which the mobile element in the form of a cross is made up of a moving magnetic element 60, a supple moving contact element 611 and a built-in element 62 serving, on the one hand, to polarise the magnetic element 60 by transmitting the field of the coils excitation 63, and on the other hand to ensure the articulation of all the parts in a hole 64 in the core of the coil 63. In this figure are found fixed poles made up of

ferrite rods

65, 66, 67 and 68 as well as fixed

contacts

69, 70, 71 and 72. A unit of contact and ferrite rod in the form of a cross could be fitted at each end of the coil. The number of contacts is then doubled and the pivot 64 suppressed.

Although the magnetic circuits of the last three methods of production are different from that of FIG. 1, the basic principles nevertheless remain, the properties and advantages of the invention are all retained.

Moreover it goes without saying that numerous modifications of detail can be used in the methods of production described, notably by substituting equivalent technical methods, without departing for all that from the outline of the invention. For example, the number of mobile elements, contacts, magnets, coils and magnetic circuits could be multiplied. The magnet could be replaced by ferrite rods or by exciting coils. Moreover, several insulated contacts could be associated on the moving elements. Lastly, moving parts in the fonn of a double cross or a T could be produced, but retaining the double guiding system according to the invention.

What I claim is:

1. An electrical switching device, comprising in combination, a magnetic element, a contact element, said two elements being assembled to form a built-in cross-shaped unit and being constituted from materials of different natures adapted to their respective magnetic and contact functions, a support for said unit, at least two magnetic poles having stationary contacts contacted by said element, at least two electrical circuits, the said cross-shaped unit being freely supported, by at least one of its points on said support so as to rock between two switching positions, said contact element in said positions being able to selectively close one of the said electrical circuits while said magnetic element selectively cooperates with one of the said magnetic poles.

2. Switching device according to claim 1, including a housing encompassing the magnetic element, a pair of magnetic circuits each of which terminates in a pole, whose polarity is induced by the excitation produced by a coil surrounding an element of each of the magnetic circuits, one extremity of the magnetic circuit being supported on a pole common to said circuits the second extremity of the magnetic element being attracted alternately towards one of the said poles, the contact element being driven by this movement so as to strike the stationary contacts.

3. Switching device according to claim 1, including a housing encompassing said magnetic element, an exciting coil, having a core, one extremity of the element supported on the end of the core, the other extremity of the magnetic element being capable of being selectively attracted by the magnetic poles, said poles being joined by a ferrite rod.

4. Switching device according to claim 3, characterized in that the magnetic circuits are selectively excited by single or double coils, actuated by reversible direct current.

5. Switching device according to claim 1, wherein said cross-shaped unit is capable of being pivoted about a point remote from its ends, such as a point in proximity to its center of gravity or around the point of conjunction of the magnetic and contact elements, the movement of the moving parts being limited, at each switching position, by two magnetic pieces and by two fixed contacts, according to two axes appreciably orthogonal.

6. Switching device according to claim 1, including an insulated case enclosing the unit of movable elements, fixed contact elements and poles.