US2823280A - Electric switch device - Google Patents

Description

H. DAVIES ELECTRIC SWITCH DEVICE Feb. 11, 1958 2 Sheets-Sheet 1 Filed Sept. 15, 1954 Feb. 11, 1958 H. DAVIES 2,823,230

ELECTRIC SWITCH DEVICE Filed Sept. 15, 1954 2 Sheets-Sheet 2 United States Patent ELECTRIC SWITCH DEVICE Howard Davies, Yeadon, Pa. Application September 15, 1954, Serial No. 456,146

Claims. (Cl. 200-87) This invention relates to electric switch devices and more particularly to switch devices of the type employing an electroinagnet and an associated armature to effect and maintain engagement of the switch contacts by energization of an eiectromagnet. Such switch devices are generally used for remote control operations, as where it is desired to start and stop a motor from a remote location.

In some instances, it is required that provision be made in the immediate vicinity of the control load for manual opening of the load circuit directly by the manual opening of switch contacts in said circuit. The purpose of this is to enable positive and assured opening of the load circuit in an emergency. Merely providing for opening the energizing circuit of the electromagnet does not suffice to meet this requirement, as the main switch contacts may stick and may not open in response to deenergizing of the electromagnet.

In the past the above requirement has been met by providing a second switch in the load circuit in series with the main switch, this second switch being manually operable and most often in a separate enclosure but sometimes being in the same box or casing with the main control switch. This has necessitated substantial additional cost and it is generally objectionable from the standpoint of the user.

These prior devices are in the form of combination units wherein there are two separate mechanisms, the manual switch with its set of contacts, and the magnetic switch with its set of contacts, an assembly which is complicated. unduly heavy and expensive to manufacture and service.

One object of the present invention is to provide an assembly wherein the foregoing disadvantages of magnetic switches have been overcome.

Another object of the invention is to provide a switch device in which provision is made for manually and directly opening the same contacts'which are normally controlled by the electromagnet, thereby eliminating the need for a second switch and the substantial additional cost incident thereto.

Another object is to provide a switch mechanism, wherein a single switch element is selectively operable magnetically and manually as a disabling switch.

Another object is to provide a novel arrangement in association with a magnetic switch whereby a live circuit, normally closed by the magnetic switch can be opened by mechanically opening said switch irrespective of the energizing circuit of the magnetic switch.

Another object is to provide a dual control for a switch in a live line whereby magnetic and manual operating means function independently upon the same switch control element.

A further object is to provide a novel magnetic switch control embodying an armature carrying a relatively slidable switch element in association with means for attaching and detaching the element from the armature whereby in attached relation the armature and the element move together to close the switch and when in detached relation 2,823,280 Patented Feb. 11, 1958 the element is free to' drop by gravity or by manual pull to open the live circuit.

A still further object is to provide an auxiliary switch in association with a magnetic switch whereby the energizing circuit for the magnet unit canbe manually controlled.

Other objects and features of the invention will be apparent from the following detailed description with reference to the accompanying drawings in which:

Fig. l is a vertical elevational view, partly in section, of a circuit control switch mechanism embodying one form of the present invention and showing the switch in open position;

Fig. 2 is a view taken substantially on line 2-2 of Fig. 1;

Fig. 3 is a view taken substantially on line 3-3 of Fig. 1;

Fig. 4 is a fragmentary vertical elevational view, partly in section, showing the switch and associated parts in circuit closing position;

Fig. 5 is a view similar to Fig. 4 but showing the parts in open circuit relation;

Fig. 6 is a view in perspective showing the relation of the contact bar with the core; and,

Fig. 7 is an exploded view of the contact bar and the toggle.

Referring more particularly to the drawings, the switch device shown is generally of conventional form and itcomprises a box or casing 10 which is adapted to be mounted in a vertical position on a suitable support such as a wall or panel-board, and which serves to house the switch structure. A rear mounting plate 11 is secured to the rear wall'of the casing 10 and serves to support the entire switch structure. A pair of angle members 12 and 13 are secured to plate 11 andare bridged by a supporting plate 14 secured to the angle members 12 and 13. The plate 14 serves to support the structure 15 which is formed by insulating material and which serves to mount the stationary terminals and switch contacts. This structure is conventional and, for the'purpose of the present application, it suflices merely to note that there are front and rear terminal members 16' and 17, and associated front and rear stationary contacts 18' and 19. Also of conventional form is' the movable contactor assembly which comprises a carriage member 20 formed of insulating material and bridge contactor members21 resiliently carried by springs 22. In Fig. l and Fig. 2, the switch. is opened and the bridge contactors 21 are out of engagement with the stationary contacts 18 and 19. Upward movement of the carriage member 20 brings the bridge contactor member 21 into engagement with the stationary contacts IS-and 19,- and thesprings 22 effect firm engagement of the contacts.

For controlling the aforesaid switch assembly, the carriage 20 is attached to-the upper end of a vertically disposed reciprocable arm 23 arranged, according to the present invention, to be actuated by a dual means'which, in one instance, is electromagnetic, and in the other instance is manual. In the first instance the arm 23 becomes an attached part of a vertically movable magnetic armature 24 operated by an associated electromagnet 25, and in the second instance the arm 23 is detached from the armature for movement relative thereto, either by gravity or by manual operation. The movable assembly comprising the carriage member 20, the contact members carried thereby, and the armature 24 is biased gravitationally to the position shown in Figs. 1 and 2. Energization of the electromagnet 25 causes upward movement of the vertically movable assembly and effects engagement of the bridge contactor member 21 with the stationary contacts 18 and 19. It will be understood that the terminals 16' and 17 are connected to the load circuit being controlled, so that the bridgmg of the stationary contacts 18 and 19 efiects closure of the load circuit which normally remains closed until the'electromagnet 25 is deenergized for remote control purposes. The energizing circuit for the electromagnet 25 extends to the remote control location at which a swltch is provided to close the energizing circuit for the electromagnet.

The 'electromagnet 25 comprises an inverted U-shaped magnetic field structure 39, formed of laminati'ons of magnetic material, and a coil 42 within the inverted structure 39. The coil 42 is included in the usual energlzlng circuit as will be understood. The associated armature 24 is of novel construction in that it includes as a detachable part thereof the switch arm 23, and a core 43 having a vertical longitudinally disposed slot 44 through which the arm 23 passes. The core 43 is formed of magnetic laminations comprising a body portion extending within the coil 42 and a lower transverse head 45 juxtaposed to the pole extensions 46 of the field structure.39 The arm 23 is preferably in the form of a thin strip having a length to project at its lower end below the core head 45, while its upper end portion traverses an opening 47 provided in the top of the U- shaped field structure 39.

In order to transmit the axial movement of the armature 24 to the switch arm 23, to close the live circuit, the lower end of the arm 23 is apertured to receive a pivot 48 for a slotted latch 49 which straddles the end of the arm 23 .and provides a bifurcated arcuate face to bear against the under-side of the core head 45, where a shoulder 50 on the latch 49 is seated upon the bridge piece 51 of a yoke-52. This yoke 52 is of U-shape and straddles the armature head '45 with its ends fastened thereto by studs 53 or other fastening means, so that with the shoulder 50 seated on the yoke bridge upward movement of the armature by the energized magnet causes the arm 23 to follow the armature and close the switch circuit.

As a means to release the arm 23 from the armature to manually open the switch circuit, the latch 49 has a lradially disposed downwardly opening slot 54 of a w dth and depth to permit free entrance of the yoke bridge piece when the latch has been turned manually to with draw its shoulder as a support for the arm 23, and in consequence the switch element and its parts are free to drop by gravity to open the live circuit. A coil spring 55 is stretched between the latch 49 and the armature 24 to restore the shoulder to its normal position on the yoke after manual release of the latch. I

For manually operating the latch 49, it is formed with a laterally projecting finger 56 having an upper cam face 57 disposed in the path of a rock arm 58 carried by a rock shaft 59 which is journalled on the wall of the box and extends to the outside of the box where it terminates in a handle 60. A fixed bracket 61 coacts with the handle 60 by providing a handle receiving notch 62 indicating an on circuit condition and a second handle receiving notch 63 indicating an o circuit condition. These two positions respectively correspond to attached and detached relations of the a m 23 to the armature 24.

From the foregoing it will be seen that the operation of the device is as follows: When the control handle 60 is'in the on position, that is notch 62 (see Fig. 1) and with the magnet circuit deenergized, the switch will be open and the latch 49 is in position to ride upwardly with the armature, so that, when the energizing circuit for the magnet is closed, the switch arm 23 and the armature will move upwardly together to thereby close the switch contacts of the live circuit. Now with the handle 60 still in the on position, the energizing circuit of the magnet can be opened whereupon the switch arm 23 and the armature 24 are free to drop by gravity to open the live circuit. This release to gravity is aided by the push of he. G

tact springs 22. The operation thus far is that of a usual magnetic switch.

Now by shifting the handle 60 to its 0 position in notch 63, the rock-shaft 59 turns the rock-arm 58 against the cam face of the latch finger 56 and swings the latch 49 counterclockwise as seen in Fig. 1 to bring the slot 54 into alinement with the bridge of the yoke 52, whereupon the arm 23 and the movable contact assembly are free to drop regardless of whether or not the electromagnet remains energized. Y

It should be noted that even if the switch contacts should stick, they will be forcibly opened by the manual operation. Again considering the handle 60 in its on" position, with the switch'closed due to the energized electromagnet and the latch connection between the arm 23 and the armature, when the handle 60 is moved to off position, the engagement of the rock-arm 58 with the 3 latch finger 56 causes a downward pull on the arm 23 and thus forcibly opens the switch.

Although the switch may be opened manually regardless of whether or not the electromagnet remains energized, it is preferred to provide means for deenergizing the electromagnet in response to the manual operation.

For this purpose an auxiliary two pole switch 64 is pro= vided, as shown in Figs. 1 and 3, This switch is mounted on the inner face of the box 10 and comprises a sta tionary body of insulating material and a shiftable rod 65 also of insulating material. The stationary body is provided with terminals 66 for the reception of supply conductors and is also provided with terminals 67 for connection to the coil 42. Associated with the terminals 66 are fixed contacts 6 8 which are engaged by contacts 69 carried by movable contact bridges 70 as shown in Fig. 3. Similarly, the fixed contacts 71 of the terminals 67 are engaged by contacts 72 also carried by the contact bridges 70. These movable contacts are mounted on the rod 65 and are normally held in engagement with the corresponding fixed contacts by the lever 74 secured to shaft 59 and substantially coplanar with the rockarm 58. As the rock-arm 58 pivots downwardly, the lever 74 likewise moves downwardly to the position shown in dot and dash lines in Fig. 3, thus permitting with the rod 65.

It should be noted that the auxiliary switch 64 is opened by small movement of lever 74 before the rock-arm 58 has moved sufiiciently to actuate latch 49. Thus, as the manual handle 60 is moved from its on position the auxiliary switch 64 first opens to deenergize the electromagnet and the main switch may open of its own accord by gravity. However, continued movement of rock-aim 58 will insure opening of the main switch in the event that the auxiliary switch should fail to open or in the event that the main switch contacts should stick.

While a particular embodiment of the invention has been illustrated and described, it will be understood that the invention is not limited thereto, but contemplates such other embodiments or modifications as may occur to those skilled in the art.

I claim:

1. In an electric switch device, stationary contacts, other contacts movable upwardly and downwardly into and out of engagement with said stationary contacts, a stationary electromagnet below said contacts, a magnetic armature movable upwardly and downwardly upon energization and de-energization of said electromagnet, said armature having a slot extending vertically therethrough, an arm extending through said slot and having its upper end connected to said movable contacts, releasable means efiecting an operating connection between the lower end of said arm and the lower part of said armature, whereby energization of said electromagnet effects engagement of said contacts and normally maintains them engaged until such time as said electromagnet is de-energized, and manually-operable means for actuating said releasable means to interrupt the operating connection between said arm and said armature, whereby to efiect disengagement of said contacts independently of said electromagnet.

2. An electric switch device according to claim 1, wherein said releasable means comprises a spring-biased latch element pivotally connected to the lower end of said arm, and a yoke connected to the lower part of said armature and normally engaged by said element, and wherein said manually-operable means includes an actuating element engageable with said latch element to disengage it from said yoke and to exert downward force on said arm to effect positive disengagement of said contacts.

3. In an electric switch device, stationary contacts, other contacts movable into and out of engagement with said stationary contacts, a stationary electro-magnet winding, a magnetic armature associated with said winding and movable toward and away from the stationary contacts upon energization and de-energization of said coil, an arm having a direction of motion parallel to the armature and connected to the movable contacts, releasable means for effecting an operating connection between the arm and the armature, whereby energization of said coil causes the arm and armature to move as a unit in the same direction to effect engagement of said contacts and normally maintain them engaged until such time as said coil is deenergized, and a manually operable means for actuating said releasable means to interrupt the operating connection between said arm and said armature, whereby to effect disengagement of said contacts independently of said electromagnet.

4. The switch device of claim 1 in which the arm having a motion parallel to that of the armature is slidably supported on the armature.

5. In an electric switch, stationary contacts, other switch contacts movable into and out of engagement with said stationary contacts, electrically operable actuating means for said movable contacts, said actuating means comprising a stationary electromagnet and a movable magnetic armature, releasable means for effecting an operating connection between said movable contacts and said armature, said electromagnet being efiective upon energization to actuate said armature to effect engagement of said contacts and to normally maintain them engaged until such time as said electromagnet is de-energized, manually operable means actuatable at will to actuate said releasable means so as to interrupt the operating connection between said movable contacts and said armature whereby to effect disengagement of said contacts independently of said electrically operable actuating means, and an auxiliary switch in circuit with said electromagnet and operable by said manually operable means.

References Cited in the file of this patent UNITED STATES PATENTS 1,354,897 Divo Oct. 5, 1920 1,582,987 Hart May 4, 1926 1,643,415 Moore Sept. 27, 1927 1,647,632 Jacobs Nov. 1, 1927 2,013,013 Van Valkenburg Sept. 3, 1935 2,449,221 Hammerly Sept. 14, 1948

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