US1974306A - Electromagnetically-controlled circuit controller - Google Patents

Description

Sept. 18, 1934. w T RAY 1,974,306

ELECTROIAGNBTICALLY CONTROLLED CIRCUIT CONTROLLER Filed March 16. 1933 2 Sheets-Sheet l Inventor:

William T Gray. by MW His Attorney.

2 Sheets-Sheet 2 WI III1' IIA I I V I l/ I W. T. GRAY ELECTROIAQNETICALLY CONTROLLED CIRCUIT CONTROLLER Filed larch 16. 1933 a 1; H a T QSQQS a v V Sept. 18, 1934.

Inventor-z William T. Gray. by W His Attorney.

Patented Sept. 18, 1934 UNITED STATES ELECTROMAGNETICALLY-CONTROLLED CIRCUIT CONTROLLER W'illiam Train Gray, Altrincham, England, assignor to General Electric Company, a corporation of New York Application March 16, 1933, Serial No. 661,141 In Great Britain March 17, 1932 6 Claims.

My invention relates to electromagneticallycontrolled circuit controllers commonly called unit switches or unit contactors of the kind adapted to be opened or closed by means of compressed air or other operating fluid, and has for an object the provision of simple, inexpensive, and reliable unit switches, which can be readily assembled together in groups.

The compressed air or operating fluid which is supplied to the pneumatically operated cylinders of the respective unit switches is controlled by electromagnetically-0perated valves energized from a suitable circuit under the control of a master controller. These switches are commonly arranged in groups, each switch or contactor being clamped to a metal support, as a steel bar for example. The air valve is biased to a closed position by means of a spring and is opened against this bias by the armature of a solenoid. This armature also controls the operation of the exhaust valve for the cylinder and is arranged so that when the solenoid is energized a cylinder is opened to the compressed air supply and when the solenoid is deenergized the cylinder is opened to exhaust. Compressed air is supplied at a sufficient pressure to insure that the main contacts are closed with considerable effort.

In accordance with the present invention, the conduit for supplying the compressed air or other operating fluid to the switch is provided in the metal supporting member on which each unit switch is mounted, thereby eliminating the use of a separate mounting bar. The switch units are secured to the metal supporting member by means of bolts passed therethrough, which bolts are drilled to allow the passage of the operating fluid from the conduit to the operating cylinder of the switch units. Furthermore, the armature of the electromagnetic valve controlling the flow of compressed air to the cylinder is attached to the center of a thin diaphragm which is slightly larger in diameter than the armature. By mounting the armature in this fashion, it is located centrally in the valve body and serves to insure a uniform air gap between its periphery and the valve body, whereby the friction which is developed by armatures of the sliding type is avoided.

For a more complete understanding of my invention, reference should now be had to the drawings, Fig. 1 of which shows in sectional elevation a unit switch of the electromagnetically-controlled, pneumatically-operated type constructed in accordance with the present invention; Fig. 2 is a front elevation of the switch shown in Fig. 1 and Fig. 3 is a rear elevation of the switch shown in Fig. 1.

Referring to the drawings, I have shown my invention in one form as applied to one switch of a group of switches which can be readily assembled together on a metal supporting member 10. In Fig. 1 it will be observed that the switch 11 includes a cast iron cylinder 12 in which there is arranged a single-acting, pneumaticallyoperated piston 13. The piston is secured at the lower end of a piston rod 14, the upper end of which is connected by an insulating member 15 to the movable contact 16 of the switch, This movable contact 16 is associated with a fixed contact 17 and is connected by a flexible lead 18 to a terminal 19. The fixed contact 1 is connected to the terminal 20 by means of low-out coils 24. The piston 13 is biased by means of a spring towards the open position of the contactor and is moved to close the contactor by compressed air admitted to the cylinder 12 through a conduit 26. The compressed air is supplied at sufficient pressure to insure that the main contacts 16 and 1'7 are closed with a considerable pressure. The contacts 16 and 17 are located in an arc chute 28 of fireproof material. The blow-out coils 24 on each side of the chute are connected between the upper terminal 20 and the fixed contact 17. The are chute 28 is located between two horizontal guides 29 and 30 and is secured in position by balls 31 and 32 carried on spring arms 33 and 34, respectively, which balls are arranged to be spring biased in notches in the lower and upper sides, respectively, of the chute. The movable member 36 of the interlock contacts 37 is attached to the piston 14.

The supply of compressed air to the cylinder 12 is controlled by an electromagnetically-operated valve 41. The valve includes an operating coil 42 disposed within a cylindrical casing 43, which coil can be energized to move an armature 44. The armature rests on the upper end of a spindle 45 which extends through the center of the coil 42 to control the operation of a compressed-air admission valve and also an exhaust valve for the cylinder 12. It will be observed that compressed air is supplied to the valve 21 through a conduit 4'7 and that the valve 48 is disposed at the end of this conduit. The valve 48 is biased to the closed position by a spring 49 in addition to the biasing force normally exerted by the compressed air. The valve 48 is connected by a thin spindle 50 to the spindle 45. The lower end of the spindle 45 carries an exhaust valve 52 which is arranged to close the outlet to the conduit 26 when the valve 48 opens this conduit to the compressed air and to open the conduit 26 to exhaust when the valve 48 is closed. The armature 44 is connected by means of a rivet 55 to the center of a thin phosphor bronze diaphragm 56 which is slightly larger in diameter than the armature 44. The thin phosphor bronze diaphragm is located in a recess 58 provided in the upper end of the casing 43. By means of this construction, the armature 44 is provided with a uniform air gap between its periphery and the operating coil and the friction which is obtained with armatures of the sliding type is avoided. Consequently, a greater voltage operating range is obtained and the construction of the valve is thereby rendered less expensive.

The supporting bar on which the unit switches are mounted is hollow in construction and serves as a conduit for supplying the compressed air, thus obviating the use of a separate air conduit. The switch units are each tightly secured to the bar by means of a bolt passing through the bar and into screw-threaded engagement with the switch frame as shown in Fig. 1. It will be understood that each bolt is drilled to provide a connecting passageway from the air supply channel 62 to the conduits of each switch. Thus, for example, the bolt 60 is drilled to provide a passageway 61 extending from the air supply conduit or channel 62 to the conduit 47 leading to the switch operating cylinder. A gasket 64 is interposed between the supporting member 10 and the switch to prevent the escape of air.

The fixed contact 17, the terminal therefor and the terminal 19 for the movable contact, the blowout coils, #4, the chute 28 and the guides 29 and 30 therefor are all secured to and supported by a pair of side plates 66 and 67 of molded insulation material. These sideplates are attached to the cast iron cylinder 12 by means of the bolts 69, '70 and 71. This construction permits of considerable reduction in the width of each switch. The cost of the switch may also be reduced by the employment of extruded sections for certain parts.

For example, the upper securing elemenu '72 is of tained between points of different potential.

extruded'section and is secured to the upper ends of the molded plates 66 and 67 by the bolts 73 and 74. The terminals 19 and 20, the bracket 51 for the fixed. contact 17, and the member 72 are respectively mounted between bosses, 75, 76, 77, and

78, respectively, provided on the inner side of the plate 66 and a corresponding set of bosses on the inner side of the plate 67. This arrangement permits adequate creepage distances to be of;-

T e blow-out coils 24 and the brackets '79 and for the guides 29 and 30 are also secured by bolts 81 and 84, inclusive, between bosses on the inner sides of the plates 66 and 67.

If at any time one of the unit switches: should. become defective, it is only necessary to unscrew the connecting bolt, as for example the bolt 60:, to remove the defective sWitclL. In case a second switch is notv immediately available, the remainder of the switches in the group can be operated. .by inserting a bolt in the place of the one removed, which bolt is not provided with apassageway. Thus, for example, I have shown in Fig. 3 the bolt 60 serving to hold the switch It to the supporting member 10, while a bolt 86 is arranged to seal the opening in. the bar lflprovided for a second unit switch,

While I have shown a particular embodiment of my invention, it will be understood,- of. course, that 'I' do not wish to be limited thereto since many modifications may be made, and-I therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. Means for mounting unit switches of the electromagnetically controlled, pneumaticallyoperated type comprising a switchsupp"orting 'member provided with a conduit for supplying compressed air to the switch, and a connecting bolt for bolting each switch to said member, said bolt being provided with a passageway for conducting the compressed air from said conduit to said switch.

2. The combination of an electromagneticallycontrolled, pneumatically operated electric switch, of mounting means for said switch comprisinga hollow supporting bar, a bolt for connecting said switch to said bar, said bolt being drilled to allow the passage of an operating fluid from said bar to said switch.

3. A switch comprising a fixed contact and a movable contact, a cylinder, a piston movable within said cylinder and connected to said movable contact for operating said movable contact from one position to another, switch supporting means provided with a passageway for supplying compressed air to said cylinder, a bolt for securing said switch tosaid supporting means, said bolt being drilled to provide a passageway for the flow of compressed air from said supporting means to said cylinder.

4-. electromagnetically -controlled, pneumatically-operated electric switch including a cylinder, a switchmperating piston arranged within said cylinder, a hollow switch-supporting bar, a bolt for securing said switch to said bar, said bolt being provided with a passageway extendingv from the portion of the bolt intermediate the sides of said bar to the inner end of the bolt, and a conduit extending from the inner end of said bolt to said cylinder for conducting the supply of compressed air from said supporting bar to said cylinder.

5. An electromagnetica'llycontrolled, pneumatically-operated electric switch including a frame for the switch, a movable contact, a piston" arranged to move within a cylinder for operating said movable contact, said frame being provided with a conduit, a valve interposed in said conduit for controlling the supply of compressed air to said' piston, and means for supplying compressed air to said valve comprising a hollow switchsupporting bar, a bolt extending through said bar and having a passageway formed therein to provide for the flow of compressed air from said bar to said valve, and means for controlling the energiza-tion of said valve for admitting compressed air' to said cylinder.

6. The combination of a pneumaticallyoperatedelectric switch having a' switch-operating' piston arranged for movement in a cylinder, a frame for supporting said cylinder, a normallyclosed valve for controlling the supply of compressed air to said cylinder, means for electrically operating said valve comprising a magnet winding, a diaphragm, a member of magnetic material secured to said diaphragm in cooperative relation with said winding, an operating 135- member extending from the mid-portion of said diaphragm to said' valve so that the energization of said coil attracts said magnetizable member to open said valve, said frame being provided with conduits one of which leads from one side 14th of said valve to said cylinder and the other ofwhich leads from the other side of saidvalve, means for supplying compressed air to said other conduit comprising a switch-supporting. member having a compressed air passageway formed 145 therein, and a bolt for securing said member to said frame, said bolt being drilled to complete a passageway for the flow of compressed air from said; member to said'other conduit.

TRAIN GRAY.

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