CA1234854A - Electromagnet for electric switching device - Google Patents

Electromagnet for electric switching device

Info

Publication number
CA1234854A
CA1234854A CA000477585A CA477585A CA1234854A CA 1234854 A CA1234854 A CA 1234854A CA 000477585 A CA000477585 A CA 000477585A CA 477585 A CA477585 A CA 477585A CA 1234854 A CA1234854 A CA 1234854A
Authority
CA
Canada
Prior art keywords
armature
electromagnet
core
outer legs
recess
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
Application number
CA000477585A
Other languages
French (fr)
Inventor
Helmut Lemmer
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.)
Square D Starkstrom GmbH
Original Assignee
Square D Starkstrom GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from EP84112847A external-priority patent/EP0160121B1/en
Application filed by Square D Starkstrom GmbH filed Critical Square D Starkstrom GmbH
Application granted granted Critical
Publication of CA1234854A publication Critical patent/CA1234854A/en
Expired legal-status Critical Current

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  • Electromagnets (AREA)
  • Details Of Connecting Devices For Male And Female Coupling (AREA)
  • Coupling Device And Connection With Printed Circuit (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE

In an electromagnet for an electric switch, particularly safety switch, an armature and a magnetic core are each formed of a pack of laminations connected to each other by rivets. The laminations of the armature and the magnetic core are equally shaped and formed so that the pack of laminations of the armature matches the pack of laminations of the core in assembly.

:

Description

1~4854 ¦¦ ~he present invention relates to a~ electromagn~t ~or ¦ an electric switching device, particularly safety switch or circuit breaker, which includes a movahle ar~ature and a magnetic core.
Armatures and magnetic cores of -the electromagnets of ! safety switches are formed of laminations assembled into packs and connected to each other by rivets.
~lectromagnets of the ~oregoing type are usually utilized in mass production for switching devices of various types. Various switching devices require, depending on their structure, size and output, different electromagnets. However efforts have been made to standardize such electroma~nets.
The manufacture of electromagnets for electric switches is usually very expensive because special cutting tools or punching tools are required for making armatures, on the one hand, and Magnetic cores, on the other hand. Furthermore, huge storage spaces are required for storing tools for making electromagnets of various sizes and constructions. Furthermore, rivets utilized for holding laminations in a pack have been differently positioned for the armature and the magnetic core so that different riveting stations have been reguired for manufacturing armatures and magnetic cores.

,~, 11 12~485~

It is an object of the present invention to provide an improved electromagnet for electric switches, particularly safety switches.
It is another object of this invention to provide an electromagnet which is easy to manufacture automatically and which is inexpensive to make.
These and other objects of the invention are attained by an electromagnet for an electromagnetic switching device, particularly safety switch, comprising a magnetic core and a ~ovable armature, said core and said armature being each formed of a plurality of superposed laminations assemhled into a pack and connected to each other by rivets, said core and said armature being each assembled of evenly-shaped laminations.
Due to the invention, instead of conventional four cutting or punching tools and respective machines, only two cutting or punching tools are re~uired.
If the electromagnet is utilized for alternating current the armature and the core each may include two outer legs and one central leg, each outer leg being formed with a widened portion extending towards the central leg, at least the widened portion of one outer leg having an end face formed with grooves for receiving therein a short circuit ring.
If the electromagnet is utilized for direct current, one of the outer legs may have at its free end an oblique surface which merges into a flat end face, the other of the 3~L~354 outer le~s having a free end fo~led with another ohlique sur:Eace and with a ~lat stop surface, said another obli~e surface and the stop surface fit said first mentioned o~lique surface and said end face, respectively when the armature i~
laid over the magnetic core, said central leg having a further oblique surface such that an air gap results between the further oblique surface of the central leg of the core and the further oblique surface of the central leg of the armature when the latter and the core are in assembly.
Each pack may be provided with holes for said rivets, and positions of said holes and said rivets in each pack may be selected so that these positions be the same for all armatures and ~agnetic core of electromagnets operated with alternating current or with direct current. A further advantage of this invention resides in the fact that instead o~ four riveting tools or riveting ~achines, required in conventional method of manufacture o~ electromagnets, only a single rivetin~ tool or riveting machine is now re~uired.
The laminations may be punched out to have a profile so that a mechanical after treatment of said laminations would be oMitted.
The central leg may have two trapezoidal projections having outer inclined surfaces and an intermediate inclined surface which form said ~urther oblique surface, the sum of the lengths of said outer inclined surfaces heing equal to the 1234~354 length of said intermediate inclined surface.
One of said outer legs may have at said end a trapezoidal recess defined by two symmetrically extendiny oblique surfaces, and another of said outer legs may have at the end thereof a trapezoidal projection which matches said recess.
One of said outer legs may have at said recess two end faces and another of said outer leys may have at said projection two stop surfaces.
The novel features which are considered as charac-teristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with addi-tional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

1~3485~

l Fig. 1 is a front view of an alternating current i magnetic core;
Fig. 2 is a front view of an electromagnet in which the armature and the magnetic core have the same construction;
Fig. 3 is a side view of the electromagnet o~ F'ig. 2;
Fig. 4 is a front view of an alternating current magnetic core of another embodiment;
Fig. 5 is a top plan view of Fig. 4;
Fig. 6 is a front view of a direct current magnetic core;
Fig. 7 i5 a side view of Fig. 6;
Fig. 8 is a front view of an electromagnet for direct current, in which the armature and magnetic core are similarly formed in accordance with Fig. 6;
Fig. 9 is a front view of a drill template for the armature and the core to be used for alternating current magnets and direct current magnets as well;
Fig. 10 is a front view of yet another embodiment of an alternating current magnetic core;
Fig. 11 is a front view of an electromagnet in which the armature and the core are ali~e and ~ormed in accordance with Fig. 10;
Fig. 12 is a side view of Fig. 10;
Fig, 13 is a front view of still further modification of a direct current core or armature; and ! -6-~ 8~ 1 Fig. 14 is a front view of a further embodiment of an electroma~netic for direct current.

, .~

34~35~L

I Referring now to the drawings in detail, and first to ¦ Figs. 1-3 thereof, these figures illustrate an electromagnet for ¦
alternating current, in which a magnetic core 1 and an armature 14 are fully identical. This is clearly seen from Fig. 2. mhe magnetic core 1 and armature 14 accordingl~ each has three legs
2, 3 and 4 extended outwardly from the base and keing parallel to each other. The core 1 and armature 14 each is comprised of a package of superposed laminations 15. The thickness of the package can vary, however the same cutting tools and riveting tools can be used to produce the core or the armature. Lamina-tions 15 are connected to each other in a pack by means of rivets 5, 6, 7, 8 and 9; it is therefore important that the positions of holes for rivets and correspondingly, of rivets for the armature and the core be selected at the same places.
Grooves 10 and 11 are punched in the leg 2. A short-circuit ring 12 is inserted into grooves 10 and 11. Fig. 2 clearly illustrates by the position of the short-circuit ring 12 that magnetic core 1 and armature 14 of the same shape are pivotable relative to each other.
A recess 13 serves, in case of the magnetic core, for connecting the core with a housing of a switching device or any other stationary element whereas, in case of an armature, this recess serves for connecting to a movable member of the switching device. As seen from Fig. 2 an air gap remain ¦ between two middle legs 3 of magnetic core 1 and armature 14.

~''.'' .

1~3A~854 ~ith reference to Eigs. 4 and 5, which show a further embodiment of the electromagnet for a circuit breaker, it will be seen that in this embodiment the structure of the core and the armature substantially coincides with that of Figs. 1-3, Portions of the structural components in Figs. 4 and 5, similar to those of Figs. 1-3, are denoted by like reference numerals.
The armature and the magnetic core each also has thr~e leys 2,
3 and 4. Outer legs 2 and 4 have each an inwardly projecting widened portion 17, 18. Grooves 19 and 20 are forrned in a lower end face of widened portion 18. Grooves 19 and 20 receive a non-shown short-circuit ring similar to the embodi~ent of Figs~ 1-3. Instead of recess 13 an opening 21 is punched in the pack of laminations of the armature and the core, opening 21 extending n~rmally to the plane of the drawing. Opening 21 receives a connecting ~in or any other suita~le connecting element.
Figs. 6 through 8 show yet another embodiment of the electromagnet in which the structures of the core and the armature are identical. The magnetic core or the armature is designated by re~erence nurneral 28. Each includes three 1egs 2, 3 and 4. An inclinecl surface 22 i~ provided on the outer leg 2. Surface 22 merges into a s~all horizontal end face 23.
Another inclined surface 25, merging into a hori~ontal stop ;
25, is provided on another outer leg 4. As shown in Fig. 8, inclined surfaces 22 and 24, as well as end faces 21 and, : :

~g-~2~3~8~5~ 1 stops 25, are shaped and dimensioned such that in assembly the armature fits the magnetic core. As seen from Fig. 8 both elements are pivotable one relative to another hy 180 once about a horizontal axis and once about a vertical axis, The middle leg 3 also has an inclined surface 26 which is punched out during manufacturing of laminations. Inclined surface 26 is formed such that an air gap 27 remains between respective surfaces 26 of the armature and the magnetic core when the f latter are in superimposed position.
Fig. 9 shows the template with the positions of holes for rivets as well as of rivets so selected that they can be the same for all armatures and magnetic cores of alternating current magnets and direct current magnets. In Fig. 9 the alternating current core and the direct current core are positioned one on the other. The alternating current core corresponds to that of the embodiment of Figs. 4 and 5. The direct current magnetic core in Fig. 9 corresponds to that of Fig. 6. Inasmuch as the armature and the magnetic core have the same structure the same positions of openings for rivets for all armatures and cores result so that only a single riveting tool or a single riveting ~achine is required for producing said openings~
Figs. 10 through 12 depict yet another embodiment in which the direct current core or armature is denoted by reference numeral 29. ~he armature or magnetic core has three l -10-I

1234~i4 legs 30, 31 and 32 which are substantially longer when a lar~e coil is re~uired. Inclined surfaces 33 and 37 and the end face 34 and stop 36 are formed in the same fashion as si~ilar surfaces in Fig. 6. In the same manner the middle leg 31 has an inclined surface 35. An air gap 3~ is for~ed between opposing inclined surfaces 35 when the armature and magnetic core are in assembled position as shown in Fig. 12.
Advantageously, laminations or sheets 15 are punched ~ out into a whole profile so that a mechanical aftertreatment, particularly of opposing surfaces of the armature and the core, could be omitted.
Fiq. 13 shows a further embodiment of the armature or the magnetic core for direct current electromagnets, in which similar reference numerals are utili7ed for the components mentioned in connection with the previously described embodiments. In this embodiment the r;liddle leg 3 has two triangular or trapezoidal projections 45 and 46, which are dimensioned so that the sum of the lengths of the outer inclined surfaces 40 and 41 of these projections is equal to the length of an intermediate inclined surface 39. Inclined surfaces 39, 40 and 41 preferably extend at an angle 20 relative to the direction of movement of the armature, but always at an acute angle. In this fashion a very large effective magnetic surface in comparison with the size of the armature or the core results, which is particularly 1234~54 - !

advantageous with three-dimensional small direct current circuit breakers. ~ small stop 42 is provided on the middle leg 3 laterally of projection 45. The trapezoidal shape of each projection ~5, 46 results in ~lat horizontal end faces A3 and 44. The entire shape of middle leg 3 with the above described surfaces ensures that during the assem~ly of the armature with the magnetic core a small uniform air gap will result between the respective opposing sur~aces. Due to such structure of the middle leg 3 it is obtained that a pulling or magnetic force of the electromagnet would act precisely in the ~iddle axis, that is in the direction of movement of the armature. Thereby the armature during its stroke would be provided with a satisfactory central guidance and friction of the movable parts, particularly the armature relative to walls or guidin~ surfaces, w~uld be reduced to minimal value. Both outer legs 2 and 4 have trapezoidal projections 47 and 51 with respective inclined surfaces 48 and 63 and horiYontal end faces 50. Inclined surfaces 48 and 63 extend at an an~le of preferably 20 to the direction of movement of the armature.
Stops 49 and 64 are respectively provided laterally of projections 47 and 51.
Fig. 14 illustrates yet a further embodiment of the direct current electromagnet with the identically shaped armature and magnetic core. he middle leg of the armature or core is shaped si~ilarly to that of Fig. 13 so that this 1~3485~

embodiment has the same advantages as the structure o~ Fig. 13.
Projection 58 here is somewhat triangular while projection 59 is of trapezoidal shape. ~ stop 60 is provided laterally of projection 58 and a small end face 61 is ~ormed on projection 58. A zigza~-shaped air gap 42 results between the respective opposing surfaces of the armature and the core in assembly.
In Fig. 14 this air gap is shown enlarged; in other words the armature and the core are not in their end position but are rather spaced from each other.
In the embodiment of Fig. 14, a trapezoidal recess 52 is provided in one outer leg of the armature or the core.
This recess has two symmetrically inclined surfaces 65 and 66.
Another outer leg of the armature or the core has in turn a trapezoidally-shaped projection 55 which fits into recess 52 of the opposite leg of the armature or the core, respectively.
Inclined surfaces 65 and 66 of recess 52 and the respective surfaces of projections 55 advantageously extend at an acute angle, preferably 20 to the direction of movement of the armature. Laterally of projection 55 are stop surfaces 56 and 57 while laterally of recess 52 small end faces 53 and 54 are formed. Since the above described oblique surfaces on outer legs 2 and A are symmetrically shaped no force components in the direction transversal to the direction of movement of the armature would act in the region of the outer legs in case of large effective magnetic surfaces so that a central guidance ~L234854 of the armature would ~e improved but friction would be reduced.
~he armature and the magnetic core have in the exemplified embodiment three legs. However, it is unde~-standable that the invention is applicahle to electromagnets having armatures and cores with two legs.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of electromagnets for electric switches differing from the types described above~
While the invention has been illustrated and described as embodied in an electromagnet for an electric switch, it is not intended to be limite~ to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without ~urther analysis, the foregoing will so ~ully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended clai~s.

.J_JL`_ l Il I

Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. An electromagnet for an electromagnetic switching device, particularly safety switch, utilized for direct current and comprising a magnetic core and a movable armature, said core and said armature being each formed of a plurality of superposed laminations assembled into a pack and connected to each other by rivets, said core and said armature being each assembled of evenly shaped laminations, said armature and said core each having two outer legs and one central leg, one of the outer legs having a free end and being formed with an oblique surface which merges into a flat end face, the other of the other legs having a free end formed with another oblique surface and with a flat stop surface, said another oblique surface and the stop surface fitting said first mentioned oblique surface and said end face, respectively, when the armature is laid over the magnetic core, said central leg having a further oblique surface such that an air gap results between the further oblique surface of the central leg of the core and the further oblique surface of the central leg of the armature when the latter and the core are in assembly.
2. The electromagnet as defined in claim 1, wherein each pack is provided with holes for said rivets, and wherein holes for said position of said holes and said rivets in each pack are selected so that these positions are the same for all armatures and magnetic cores of electromagnets operated with direct current.
3. The electromagnet as defined in claim 1, wherein said laminations are punched out to have a profile so that a mechanical aftertreatment of said laminations is omitted.
4. The electromagnet as defined in claim 1, wherein said central leg has two trapezoidal projections having outer inclined surfaces and an intermediate inclined surface which form said further oblique surface, the sum of the lengths of said outer inclined surfaces being equal to the length of said intermediate inclined surface.
5. The electromagnet as defined in claim 4, wherein one of said outer legs has at said end a trapezoidal recess defined by two symmetrically extending oblique surfaces and another of said outer legs has at the end thereof a trapezoidal projection which matches said recess.
6. The electromagnet as defined in claim 5, wherein one of said outer legs has at said recess two end faces and another of said outer legs has at said projection two stop surfaces.
7. The electromagnet as defined in claim 3, wherein said central leg has two trapezoidal projections having outer inclined surfaces and an intermediate inclined surface which form said further oblique surface, the sum of the lengths of said outer inclined surfaces being equal to the length of said intermediate inclined surface.
8. The electromagnet as defined in claim 7, wherein one of said outer legs has at said end a trapezoidal recess defined by two symmetrically extending oblique surfaces and another of said outer legs has at the end thereof a trapezoidal projection which matches said recess.
9. The electromagnet as defined in claim 8, wherein one of said outer legs has at said recess two end faces and another of said outer legs has at said projection two stop surfaces.
CA000477585A 1984-03-31 1985-03-27 Electromagnet for electric switching device Expired CA1234854A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP84103594.2 1984-03-31
EP84103594 1984-03-31
EP84112847A EP0160121B1 (en) 1984-03-31 1984-10-25 Electromagnet for electrical switching devices, particularly for contactors
EP84112847.3 1984-10-25

Publications (1)

Publication Number Publication Date
CA1234854A true CA1234854A (en) 1988-04-05

Family

ID=26091597

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000477585A Expired CA1234854A (en) 1984-03-31 1985-03-27 Electromagnet for electric switching device

Country Status (7)

Country Link
AU (1) AU567652B2 (en)
BR (1) BR8501405A (en)
CA (1) CA1234854A (en)
DK (1) DK129985A (en)
ES (1) ES295895Y (en)
MX (1) MX157603A (en)
NO (1) NO851303L (en)

Also Published As

Publication number Publication date
MX157603A (en) 1988-12-02
ES295895U (en) 1987-06-16
AU567652B2 (en) 1987-11-26
NO851303L (en) 1985-10-01
BR8501405A (en) 1985-11-26
ES295895Y (en) 1987-12-16
DK129985D0 (en) 1985-03-22
DK129985A (en) 1985-10-01
AU3952185A (en) 1985-10-03

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