US3651437A - Electromagnetic contactor - Google Patents

Abstract

A small type electromagnetic contactor including a pivot-less carrier for a movable core adapted for stable magnetic coupling to a fixed core and to easy-assembly structure. The movable core substantially of rectangular body and having a reverse U-shaped section has at the lower end of both legs a lateral inward and outward extension so as to provide a downward groove in the body of substantial T-shape. The carrier includes an upward projection of a substantially complementary shape to the T-shaped groove of the core, and the core is resiliently mounted on the carrier projection. The carrier holds in its body a plurality of resiliently movable contacts. Fixed contacts to oppose these movable contacts are arranged in arrays within an insulating box separated from each other by walls of the box. An insulating lock means is mounted on the fixed contacts to lock them in a fixed position.

Description

United States Patent Kiyoshi 51 Mar. 21, 1972 [54] ELECTROMAGNETIC CONTACTOR [72] Inventor: Yamada Kiyoshi, Kadoma, Japan [73] Assignee: Matsushita Electric Works, Ltd., Osaka,

'Japan [22] Filed: Mar. 19, 1971 211 Appl. No.: 125,950

Primary Examiner-Harold Broome Attorney-Pierce, Schefi'ler & Parker [57] ABSTRACT A small type electromagnetic contactor including a pivot-less carrier for a movable core adapted for stable magnetic coupling to a fixed core and to easy-assembly structure. The movable core substantially of rectangular body and having a reverse U-shaped section has at the lower end of both legs a lateral inward and outward extension so as to provide a downward groove in the body of substantial T-shape. The carrier includes an upward projection of a substantially complementary shape to the T-shaped groove of the core, and the core is resiliently mounted on the carrier projection. The carrier holds in its body ,a plurality of resiliently movable contacts. Fixed contacts to oppose these movable contacts are arranged in arrays within an insulating box separated from each other by walls of the box. An insulating lock means is mounted on the fixed contacts to lock them in a fixed position.

4 Claims, 5 Drawing Figures PATENTEDHARZI I972 SHEET 2 BF 4 n m I I n v r V w 27 ELECTROMAGNETIC CONTACTOR This invention relates to electromagnetic contactors of small type.

There have already been suggested electromagnetic contactors of such structure that a plurality of opening and closing elements respectively comprising movable contacts and fixed contacts arecontained in a plurality of opening and closing chambers, which elements are opened and closed by means of an operating lever or a carrier coupled to an electromagnet. In those electromagnetic contactors of the type referred to, there have been involved various defects in that contact between the opening and closing elements becomes unstable due to such reasons as the fixed contacts are loosened after repeated vibrations, level difference at contacting position is caused to occur due to dimensional error so that proper contacting clearance cannot be obtained, or the like. Further, the conventional operating lever has been of such type that its respective ends are engaged with the movable core and then pivoted. In such type, however, there have been involved such defects that the engaging section of the lever has had to occupy a large percentage of the whole volume, the pivoting has required a suitable jig, the wear in the structure has been so great that its life has been short and so on. The present invention has been suggested to remove such defects as above.

A principal object of the present invention is, therefore, to provide an electromagnetic contactor of a small type and yet has a high performance and which is easy to manufacture.

Another object of the present invention is to provide an electromagnetic contactor having a movable core which is adapted to be of lightweight, long life and low noise type and is formed in a unique shape.

A further object of the present invention is to provide an electromagnetic contactor in which the engagement of the operating lever for opening and closing contacts -with the movable core is not of the pivot type so that the same is easy and rapid and the core is prevented from being inclined so as to carry out stable operation.

Afurther object of the present invention is to provide an electromagnetic contactor in which any loosening at coupling sections between respective parts due to mechanical vibrations of fixed contacts at the time of contact opening and closing or shocks at the time of connecting external terminals thereto is prevented from occurring.

It is a still further object of the present invention to provide an electromagnetic contactorof the type that the fixed contacts can be arranged in an array at predetermined positions.

The present invention shall be explained in detail with reference to accompanying drawings, in which:

FIG. 1 is a side elevation of the electromagnetic contactor according to the present invention. 7

FIG. 2 is a cross section substantially at the center of the contactor shown in FIG. 1.

FIG. 3 is a perspective exploded view of respective parts except covering case of the contactor of the present invention.

FIG. 4 is a perspective view showing bottom side of coil block of the contactor of the invention.

FIG. 5 is a fragmentary vertical section taken along line V- V in FIG. 2 showing the structure of the contactor.

While the present invention will be set forth with reference to the particular embodiment as illustrated, it is not the intention to limit the invention to such particular embodiment, but rather to include all possible modifications, alternatives and equivalent arrangements within the scope of the appended claims.

Referring now to the drawings, 1 is an E-shape fixed core, 1 is a coil block,'and 3 isa coil'bobbin which is engaged in recessed sections of said E-shape fixed core 2. At the bottom surface of said coil bobbin, there is provided a guide wall 4 (FIG. 4), which in turn is provided with semicircular stubs 5 at both opposed endwise sides. 6 is an auxiliary core, which has an aperture 7 at the central raised part and recesses 8 at both longitudinal endwise edges of the aperture 7. 2 is a moving core, which comprises a substantially U-shaped body part 10 having at its respective legs 11 lateral extensions 12 so as to form a substantially T-shaped load-engaging groove 13. For the material of the moving core}, a rod shaped metal having high magnetic characteristics may be cut to form the core, or a sintered alloy material may be used. 12 is a, carrier made of an electrically insulating material and provided with an engaging projection 14 substantially of T-shape in section and dimensioned so as to be relatively smaller than said load-engaging groove 13 of the moving core 9. The upper surface of said engaging projection 14 is formed to have a wavy recess 15. The carrier 19 is further provided on its upper surface with a pair of receptacles 17 for coil springs 16. In the main body of the carrier 12, there are provided a plurality of openings 18, in each of which a moving contact 20 is inserted, which is urged upward by means of a coil spring 21 inserted between lower surface of the contact 20 and lower edge of the opening 18. 22 is a pair of fixed contacts, which are respectively arranged so as to oppose each of contact points of the moving contact 20.

Since the carrier L2 in the illustrated embodiment is shown to have four openings 18, a total of four moving contacts 20 are arranged in the carrier 12 and four pairs of the fixed contacts 22 are coupled with these moving contacts 20. In FIG. 3 only one of the moving contacts 20 and a single pair of the fixed contacts 22 are illustrated for the purpose of simplicity.

The above mentioned fixed contacts 22 are installed in a switch box 23 made of an insulating material such as a synthetic resin. 24 is a longitudinally extending space or chamber, which is provided with a plurality of switching chambers 25 arranged at both sides of the chamber 24 and open at the center, respectively. 26 are grooves made in each of the walls 31 defining the switching chambers 25 and in alignment with each other so as to connect the respective chambers 25 on each side of the chamber 24. Each of the aforementioned pair of fixed contacts 22 is received in each of said switching chambers 25. Lower end 27 of each of the pair of fixed contacts 22 is extended through the bottom section of the box 23 so as to extend outwardly to form terminals arranged in parallel relation to each other. 28 is a pair of insulating lock plates, each of which is provided at its lower edge with downwardly projecting parts 29 and recessed parts 30.

The projecting parts 29 extend between the adjacent walls 31 and the recessed parts 30 engage the bottoms of the grooves 26. The lock plates 28 are respectively thus inserted in the grooves 26 in the respective sides of the space chamber 24. The walls 31 are further provided respectively at their inner end portions with Y-shaped guide sections 32, which engage triangular projections 33 provided on both side surfaces of the carrier 12. 34 is a V-shaped plate spring, which is inserted in the space between the U-shaped load-engaging groove 13 of moving core 2 and the V-shaped recess 15 of the carrier 12 and is adaptedto prevent undesirable chattering of the moving core 2 when the same is engaged with the carrier 12 as detailed later. 35 shown at the top in FIG. 3 is an arcuate plate spring to be inserted between the top of the fixed core I and upper wall of a metal case 36 to enclose the above structure (FIG. 2).

In assembling the electromagnetic contactor of the present invention as set forth above, the coil is nested between the side leg 38 and center legs 39 of the -shaped core 1 and the auxiliary core 6 is then butted against the lower faces of the coil & and the side legs 38 of the core 1. At this time, the lower end guide wall 4 of the coil bobbin 3 is engaged in the aperture 7 of the auxiliary core 6 and, at the same time, the semicircular stubs 5 of the bobbin 3 are received in the recesses 8 of the core 6. Then, the engaging projection 14 provided above the carrier 19 is inserted longitudinally into the load-engaging groove 13 of the moving core B. At this time, inner edges of the lateral extensions 12 of the core 2 engage grooves 40 of the projection 14 and the V-shaped plate spring 34 is interposed between the top surface of the groove 13 in the core and the upper surface of the projection 14 so as to rest in the V-shaped recess 15. The moving contacts 20 are respectively inserted in each of the openings 18 of the carrier together with the coil springs 21 respectively interposed between central lower surface of the contact 20 and lower edge of the opening 18. The carrier 12 together with the moving core 2 and the moving contacts 20 as noted above is then inserted in the chamber 24 in the switching box 23. Then, the side wall projections 33 of the carrier 12 are engaged respectively in the guide sections 32 provided dii'the walls 31 in the box 23. The fixed contacts 22 are respectively installed in the switching chambers 25 with their lower ends 27 inserted in slitlike holes provided in the bottom of these chambers 25. The insulating lock plate 28 is bridged across and over respective walls 31 so that the recessed parts 30 will be engaged in the array of the slots 26 and the projecting parts 29 will butt against head section of each of the fixed contacts 22 so as to lock the contacts 22 in their fixed position. Further, the coil springs 16 are placed in receptacles l7 therefor on the carrier H, and the assembly of the E-shaped core 1, coil 1 and auxiliary core 6 is placed on the outer periphery of the switching box 23, whereby the springs 16 are pressed downwardly by the lower surface of the core 6 and, thus, the carrier '12 is urged downwardly against the bottom of 24. Thus, it will be appreciated that the moving core 2, as well as the moving contacts 20, are urged to rest in their normal nonoperative position. The auxiliary core 6 is provided at its periphery with a plurality of recesses 43 and, on the other hand, the periphery of the box 23 is provided with a corresponding number of bosses 44 to engage in the recesses 43 when the core 6 is placed in position. The case 26 is placed over the assembly with an interposition of the plate spring 35 at the top position of the core 1, so as to urge the whole structure in the thus assembled position. By means of bent sections 37 urged into recessed sections 42 in the box at the lower edge of the case 36, the case is fixed to the box 23.

With the above arrangement, the present invention performs such various features as follows.

Since the moving core 2 of the electromagnetic contactor according to the present iiivention is formed to have a lateral extension 12 at each of the legs 11 of the substantially U- shaped body part so as to form the substantially T-shaped load engaging groove 13, the moving core may oppose the auxiliary core 6 with a sufficiently wide area of the lateral extensions 12 which are enclosed inside the central raised portion of the auxiliary core 6, so that the contactor can provide a higher output. In addition, the moving core 9 is adapted to hold the carrier 19 in the hollow section such as the U-shaped groove 13 and thus the moving core can be made to be of a light weight. Further, selecting the longitudinal length] of the moving core 2 (FIG. 3) to be of any desired value, it is possible to obtain a contactor having a moving core of suitable dimension for the required output.

In the electromagnetic contactor according to the present invention, further, the carrier 19 is provided at its top with the engaging projection 14 having the upwardly directed V- shaped recess 15, and the moving core 2 is formed to have the above mentioned groove 13 which engages said projection 14 so as to hold the latter therein, and the V-shaped plate spring 34 is enclosed in the space between upper inside surface of the groove 13 and the V-shaped recess 15. Because of this arrangement, the assembly work of the carrier and moving core is very easy. At the same time, the V-shaped plate spring 34 inserted between these two components serves to insure that the moving core is always subjected to the magnetic attraction at its proper and correct areas even when there occurs certain inclination of the core and carrier, so that the contactor will perform its operation without any trouble regardless of any fluctuation in positional relationship between them.

Further in the electromagnetic contactor according to the present invention, it is possible to minimize the size of the whole structure of the contactor and its assembly can be carried out very quickly while maintaining desired accuracy of mutual positional relationships between the respective component elements, since the E-shaped fixed core 1 and the switching box 23 arranged respectively above and below the auxiliary core 6 are mounted and fixed in the metal case 36 through the compression plate spring 35, while the coil block 2 bearing the E-shaped fixed core 1 is coupled to the auxiliary core 6 with the guide wall 4 at bottom surface of the bobbin 3 as engaged in the central aperture 7 of the core 6, and at the same time the auxiliary core 6 is positioned above the box 23 as its peripheral recesses 43 engage the bosses 44 of the box 23, as well as the above discussed engaging feature of the core 2 and the carrier 19, so that all the elements are assembled with each other without requiring any special fixing means.

The present invention is further featured in that, since the fixed contacts 22 are fixed to the bottom of the switching box 23 and the insulating lock plates 28 are inserted between upper part of these contacts 22 and the auxiliary core 6 covering the switching box 23, the fixed contacts 22 are locked by means of these plates 28 against upward movement due to mechanical shocks thereto when the movable contacts 20, resiliently secured in the carrier 19, are urged into contact with the fixed contacts 22 by the actuation of the electromagnetic means. The lock plates 28 are also effective in preventing any level difference from occurring between the various fixed contacts 22.

What is claimed is:

1. In the electromagnetic contactor, the combination comprising E-shaped fixed core having both side legs longer than a center leg, a coil block wound around said center leg of the E- shaped fixed core through a coil bobbin, a plate shape auxiliary core positioned in contact with said side legs of the fixed core and having an aperture at the positionopposing to said center leg, a moving core formed to have a substantially reverse U-shaped body part and lateral extensions at lower ends of both side legs of said body part, said moving core being freely engaged in the aperture of said auxiliary core and being opposed with its upper surface of the body part to lower end surface of the center leg of the fixed core, a carrier having a projection at the top for engaging inside the reverse U- shaped body part of the moving core and a plurality of openings at the lower part, a plurality of moving contacts respectively including movable contacts provided at the respective ends, each of said moving contacts being passed through each of said openings of the carrier and resiliently biased at the center against upper wall of the opening by means of a compression spring arranged at lower wall of the opening, a plurality pair of fixed contacts each having a contact to oppose to each contact of said moving contacts, a switching box for securing therein said pairs of fixed contacts and including a guide means for supporting slidably said carrier having the moving contacts, and a case enclosing the E- shaped fixed core and forming outer shell structure together with said box as coupled thereto.

2. An electromagnetic contactor according to claim 1, wherein the coupling position of said carrier to the moving core is provided with a space between the top of the engaging projection of the carrier and upper wall of the reverse U- shaped groove of the core and a compression spring is interposed in said space, thereby any inclined error of the core is absorbed.

3. An electromagnetic contactor according to claim 1, wherein said auxiliary core is provided at its outer periphery with a plurality .of recesses and at its inner periphery of the aperture with a plurality of guide recesses, said outer peripheral recesses are adapted to engage a plurality of bosses provided at upper opening peripheral edge of said switching box and said inner peripheral guide recesses are adapted to receive therein a plurality of projected stubs provided downwardly at the lower surface of said coil bobbin.

4. An electromagnetic contactor according to claim 1, wherein insulative locking means is interposed between said auxiliary core and upper surface of said fixed contacts fixed in said switching box.

1 m v w I CENMPICAEE (30am "BL-0N r 3: 5 D March 21, 1972 ITNQR C01 (3) KIYOSHI YAMADA '1 I: is certified that error appears in flaeabove-identificd patent and that said Letters Patent are hereby corrected as shown below The l'n'ventorr'sname is incorrectly giveffl It should be: D

- KIYOSHI YAMADA Sig ned aqdQ s q ale'd 20th day .o'f 'Jx g ne. 1972,-

E L) Attest: I I H I. l h I WARD MILET HERMRH ROBERT GQTT SC HALK fi zfiesting Offibe'ni Commigsippex of Patents r -wmrrwr f p m7. T Gain 1 All A. L .411 O2 LORLLA A.

Pazcn: No. 3,651,437 Dated March 1972 :..v-.-.:Qr z KIYOSHI YAMADA I: is certified that error appears in the above-identified parent :1 char. said Letters Patent are hereby corrected as shown below} The inventor. shame is incorrectly give nQ It should be: I

'.- KIYosHI YAMADA and thi R 9 (SEAL) 'Atcest: r EDWARD M.FLETQ}ER J.R. ROBERT QQ C Attescing O'ffiB'I'- 4 I s of Patents

Claims (4)

1. In the electromagnetic contactor, the combination comprising E-shaped fixed core having both side legs longer than a center leg, a coil block wound around said center leg of the E-shaped fixed core through a coil bobbin, a plate shape auxiliary core positioned in contact with said side legs of the fixed core and having an aperture at the position opposing to said center leg, a moving core formed to have a substantially reverse U-shAped body part and lateral extensions at lower ends of both side legs of said body part, said moving core being freely engaged in the aperture of said auxiliary core and being opposed with its upper surface of the body part to lower end surface of the center leg of the fixed core, a carrier having a projection at the top for engaging inside the reverse U-shaped body part of the moving core and a plurality of openings at the lower part, a plurality of moving contacts respectively including movable contacts provided at the respective ends, each of said moving contacts being passed through each of said openings of the carrier and resiliently biased at the center against upper wall of the opening by means of a compression spring arranged at lower wall of the opening, a plurality pair of fixed contacts each having a contact to oppose to each contact of said moving contacts, a switching box for securing therein said pairs of fixed contacts and including a guide means for supporting slidably said carrier having the moving contacts, and a case enclosing the E-shaped fixed core and forming outer shell structure together with said box as coupled thereto.

2. An electromagnetic contactor according to claim 1, wherein the coupling position of said carrier to the moving core is provided with a space between the top of the engaging projection of the carrier and upper wall of the reverse U-shaped groove of the core and a compression spring is interposed in said space, thereby any inclined error of the core is absorbed.

3. An electromagnetic contactor according to claim 1, wherein said auxiliary core is provided at its outer periphery with a plurality of recesses and at its inner periphery of the aperture with a plurality of guide recesses, said outer peripheral recesses are adapted to engage a plurality of bosses provided at upper opening peripheral edge of said switching box and said inner peripheral guide recesses are adapted to receive therein a plurality of projected stubs provided downwardly at the lower surface of said coil bobbin.

4. An electromagnetic contactor according to claim 1, wherein insulative locking means is interposed between said auxiliary core and upper surface of said fixed contacts fixed in said switching box.

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