US1696570A - Oil switch - Google Patents

Description

Dec. 25, .1928.

J. D. HILLIARD OIL SWITCH Filed March 30. 1922 2 Sheets-Sheet 1 lnVen-tor: John D. Hillier-d,

His -t-lrorneg.

Dec. 25, 1928.

J. HILLIARD on; swrrdn Filed March 30. 1922 2 Sheets-Sheet 2 Inventor: John D. Hilliard,

His fl-b-borneg.

Patented Dec. .25, 1928.

UNITED STATES PATENT OFFICE.

JOHN D. HILLIABD, 0F S CHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

om swncn.

. C Application filed March 30, 1922. Serial No. 548,155.

chamber at the separation of the contacts] In patents to Hilliard & Parsons No. 1,009,- 748, and to Hewlett No. 1,039,395 apparatus is disclosed wherein circuits are broken under oil by the forcing apart of the contacts after an initial separation thereof, under the influence of pressure created by the vaporization and dissociation of the oil. The operation of the present invention is similar to that disclosed in the patents referred to and in certain respects the present invention may be said to constitutean improvement thereon.

A further object of the present invention is to provide a circuit breaker having contacts adapted to be separated beneath the surface of a liquid and wherein a rapid separation of the contacts is produced by the sion which occurs when the are is drawn in the liquid. By so causing a rapid separation of the contacts the duration of the arc is short and consequently a less quantity of gaseous material is formed. This diminishes the shock to which the switch is sub jectcd and therefore contributes materially to an increased circuit breaking capacity;

A further object is to facilitate the rapid separation of the contacts by forming the movable contact or contacts of light iuass and preferably causing the'same to be freed from all operating mechanism at the same time they are being separated by the forces of the explosion. In one form of my invention I disclose a contact which presents a large surface to the action of'the pressure created in order that the contacts may be separated with greater speed. My invention also contemplates the employment of an imcombined action of springs and the explo- .proved device b which the moving contact is decelerated a ter the'arc-is broken.

A further object is to provide a switch in which the circuit is broken by one pair of contacts designed for rapid separation as above described and in which the circuit is made by a separate pair of contacts designed for a rapid closing movement under the influence of suitable operating mechanism. It is advisable that the contacts employed in closing the circuit be of heavier and more rugged construction than those employed in opening the circuit and that the closing movement be made at high speed. This provision of separate pairs of contacts prevents the burning of the circuit breaking contacts which would ordinarily occur were they used to close the circuit. The switch may therefore be operated a great number of times before it is necessary to repair the contacts or make an inspection of same.

Gener'all the inspections will be limited to an examination of the circuit breaking contacts because the other contacts, being of heavier construction, will' deteriorate very slowly. To minimize the arcing at the circuit making contacts I preferably operate the same under oil or other insulating liquids. I also provide forthe separation of the circuit breaking contacts under oil or other insulating liquid which with the high speed of the contacts and pressure produced serves to hasten the extinction of the are.

In addition to the two pair of contacts above mentioned I preferably employ a third pair ofcontacts which are in parallel with the circuit breaking contacts and are constructed to carry the greater port-ion of the line current when the switch is closed. These contacts are likewiseoperable' under an insulating liquid and suitable operating mechanism is provided so as to insure a wide se aration of the same carrying fcontacts prior to any separation of the arcing contacts. p

A still further object ofmy invention is to provide an operating and interlocking mechanism for causing the several pairs of contacts to function in proper sequence.

Numerous other objects and advantages will appear from the following description taken in connection with the accompanying drawing wherein Fig. 1 is a side view partly in section and partly diagrammatic of a switch embodying my invention, and Fig. 2 is a detailed section showing a modified form of the current interrupting means.

Referring more particularly to Fig. 1, 10 represents the circuit making and breaking device which is adapted to be mounted upon a movable truck 11, and 12 represents generally the operating means for the device 10 which is adapted to be mounted upon a stationary support 13.

Referring to the circuit making and breaking device 10, this comprises thecurrent interrupting device 14, a circuit making device 18 and main current carrying switch 19. Stationary terminals 22 and 23 are adapted to cooperate with the main terminals 24 and 25 of the switch.

The current interrupting device 14 comprises a metal container 26 mounted upon an insulator 27, which container is adapted to be filled with oil or other liquid. Within the container 26 is a lower stationary contact 30 and an upper movable contact 31. The contact 30 is electrically connected with the container 26 while the contact 31 is adapted to operate through an insulating bushing 32 supported at the top of the container. The container 26 .is formed with a horizontal partition 33 provided with a central opening 34 through which the movable contact 31 is adapted to operate. A disc or projecting portion36 is secured to the movable electrode at a point above the insulator 32 and between this disc and the top of the insulator I arrange springs 37 and ,38 'whose function is to lift the movable electrode when the same is released by operation of a latch 40. The latch 40 is pivoted at 41' to a plate 42 mounted upon the insulator 32. Means is provided at 43 for forcing the movable contact 31 downwardly to close the contacts. An outlet passage is provided at 45 to permit escape of material from the container at the separation of the contacts 30- and 31. Forming a portion of the outlet passage is a chamber 46 adapted to be filled with gravel whose function is to prevent the throwing of oil, in case oil is used, and to cool the gases which are ejected to a point at which they may be expelled into the atmosphere without danger of ignition. r

Mounted upon the truck 11 is a container 50 adapted to be filled with oil to the level indicated by the dotted line and which has extending through the top thereof three stationary terminals 51, 52 and 53 suitably insulated from one another. The central terminal 52 is connected by means of a conductor to the metallic container 26 of the current interrupting device. The terminal 51 is connected to the main terminal 25 adapted to formcontact with the stationary terminal 23 and the terminal 53 is connected to the main terminal 24 which is adapted to form contact with the stationary terminal 22 as heretofore described. Secured to the central terminal 52 are switch contacts 55 and 56 which are movable relative to said terminal and are adapted to make contact respectively with terminal 51 and terminal 53. These contacts are controlled by operating rods 58 and 59 which are connected by detachable connection 60 to the operating rods 61 and 62 and extend upwardly through the support 13.

A lever 63 is pivoted at 64 to a conductor 65 which as shown forms an upward extension of the terminal 51. .The terminal 51 is electrically connected to the contact 31 by means of the lever 63 and flexible conductors 66 and 67. As a means for operating the latch 40 I provide a disc or lug 66' formed upon the operating rod 61 which is adapted to engage the end of the bell crank lever 68 pivoted at 69 to one end of the lever 63 and at 110 to one end of a link 75, the other end of which link is pivoted to the latch 40. It will be noted that upon lowering of the disc 66' the bell crank lever 68 will turn about its pivotal connection 69 with the lever 63, thereby causing the latch 40 to be withdrawn from the disc 36., In so lowering it will likewise be seen that the contact 55 will be separated from the terminal 51.

As a means for forcing the movable contact 31 of the circuit interrupting device 14 into contact with the lower contact 30 I provide a rod 43 which is formed at itslower end with a socket 70 and adapted to receive the upper end of the movable contact. This rod is operated by means of a bell crank lever 71 pivoted upon the brackets '72 which in turn are supported upon a member 13'. The movement of the bell crank lever 71 is also utilized to move the operating rod 61 for the contact 55 by means of an extension 73 adapted to press against the lower side of the disc 74 formed on the rod 61. It will thus be seen that as the rod 43 is moved downwardly to force the movable contact 31 into contact with stationary contact 30 that the extension 73 moving upwardly will lift the operating rods 61 and 53 and force the contact 55 of the main current carrying switch 19 into engagement with the terminal 51. Interposed between the disc 74 and the top of a supporting member 76 is a spring 77 whose function is to force the rods 61 and 58 downwardly to cause the movable (:Ontact 55 to be separated from the terminal 51. The operating rod 61 is adapted to be held in its uppermost position by means of a toggle 78 formed of a link 79 secured to load solenoid or magnet 106 to trip the toggle 78 and permit the rod 61 to move downward under the influence of spring 77.-

The bell crank lever 71 is adapted to be operated by means of a solenoid 82 having a core 83 adapted to be connected to the arm 84 of the bell' crank lever, A spring 85 secured at one end to the Support 72 and atthe other to the arm 73 is made to rotate the bell crank leverin a clockwise direction and thus acts in opposition to the solenoid 82.

The operating rod 62 for the contact .56 of the'circuit. making device 18 is adapted to be operated through a bell crank lever 86 by means of a solenoid 87. A toggle 88 is adapted to lock the opera-ting rod 62 in its raised position. This toggle comprises a link 89 pivoted to the support 13 and a bell crank lever 90 pivoted to the outer end ofthe'arm 91 of the bell crank lever 86. A solenoid 92 is provided with a core 93 which is adapted to be raised when the solenoid is energized to give a blow to-the outer end of the bell crank lex'er 90 to break the toggle 88 and permit the rod 62 to fall into its circuit opening position.

A controlling system for the operating means, above described, comprises a source of supply 91, manual switches 92 and 93'.

a switch 94 connected to the member 63 and opened by the raising of the contact 31, switch 96 operated by means of a lever 97 pivoted at 98 and connected at 99 to the rod 61 which is adapted to operate the same, a switch 100 likewise operated by the rod 61 and a switch 101 operated by the core 102 of the solenoid 87. The operating lever of the control switch 92 is connected to one side of the source 91 and is adapted to cooperate with contacts 103 and 104. Contact 103 is connected through the solenoid 82 and switch 101 to the opposite side of the source 91. Contact 104 is connected through a the interlocking switches 100 and 94 with the operating coil of the sol.cnoid 87. The manual switch 93' completes the circuit from one side of the source 91 through interlock 96 and the solenoid 92 to the opposite side of the source.

In operation assume all of the contacts in the main circuit, that is. the switches 14, 1S and 19, open and in order to close switches 14 and 19, the movable contact of.

upward pressure exerted against the disc .74 which is pinned to the rod 61 and also compresses the spring 77 land straightens the toggle 78.- This locks the contactsof switch 19 in closed position; A subsequent motion of the control switch 92' 'to central neutral position results'in'the' withdrawal of the core 83 of the'solenoid 82 by reason of the action of the spring 85. The rod 43 is in this manner raised clear-of theco'ntact rozl. 31 of the switch 14, so that upon a subsequent opening of the switch 14 the rod will be free to rise. The end of the arm 7 3 which engages the disc 74 on 'rod 61-movesdownwardly,-but as the rod '61 is locked in its upper portion by means of the toggle 78, it does not follow. the movement "ofthe arm 73 and the switch 19 therefore remains closed. To closeithe circuit through the breaker at the switch 18, the control lever of switch 92' is thrown from its neutralposition to the right, thus energizing the magnet 87 which, through the bell crank lever 86 raises the operating rod 62 and straightens the toggle 88, thereby closing the switch 15 and. locking the same inclosed position. After the closure of the switch 18, if a short circuit occurs upon the system, the overload magnet 106 is energized, thereby breaking the toggle 78 and causing the rod operating the switch 19 be forced downwardly by means of the spring 77. The operation of this rod serves to trip the latch 40 by engagement of the stop 66' with the bell crank 68. The springs 37 and 38 then acting upon the contact rod of the switch 14 raises the same rapidly, this raising being aided by the pressure generated by the are formed in the lower part of the oil vessel 26. The opening of'switches 14 and 19 automatically opens control switches 94 and 100 and closes control switch 96.

I have provided means which necessitates that the power circuit be closed at the switch 18 where the closing action can be made at high speed and under heavy pressure. If at the time of the operation, that is, with switches 14 and 19 opened and switch 18 closed, an attempt be made to close switches 14 and 19 by means of the control switch 92, no current will flow to the solenoid 82 by reason of the fact that the circuit to this solenoid is broken at the switch 101. In order, therefore, to close switches 14 and 19, it is necessary first to open switch 18, which is accomplished by closing control switch 93, thereby closing the circuit through the solenoid 92, the core of which-is moved upwardly to impart a blow to the bell crank lever 90 of the toggle 88 which permits the switch 18 to open and closes control switch 101. If by any chance when the switch 18 is open an in effectual attempt be made to close the switches 14 and 19 by moving switch 92 to the left the circuit through the solenoid 87,

cuit-s through switches 14 or 19 are open.

which effects the closing of switch 18, will be broken at the switch 94 or at the switch '100. It will, therefore, be impossible to close the switch at 18 if either of the parallel cir- If 14 alone were closed, the result of closing the switch 18 would be to throw the entire current through the contacts 30 which are not designed to carry the same. If the switch 19 alone were closed and the switch 18 were subsequently closed, a later short circuit current would be interrupted at the switch 19 which is not constructed to perform this function. If it is desired to open the circuit breaker manually suitable means may be provided for closing a circuit through the magnet 106 whereby the toggle 78 will be tripped and the switches 19 and 14 opened.

In Fig. 2 I have shown means for imparting to the movable contact of the circuit in terrupting switch a very high velocity under the influence of the pressure created at the separation of the contacts and also means whereby the movable contact may be quickly brought to rest after the archas been interrupted. For the former purpose I provide a disc or other enlargement 111 upon the contact 31 which is adapted to move within a cylindrical opening 112 formed in a partition 113 extending across container 2(3and dividing the same into a lower and an upper chamber. The function of the disc 111 is to offer to the action of the fluid under high pressure ,a large surface so that the contact 31 will be moved with a greater force. It is of course understood that the container 26 in the form shown in Fig. 2 should contain an insulating liquid preferably to the level indicated by a dotted line.

As a means for decelerating the electrode 31 I provide a dashpot 115 submerged in the oil in the container. This dashpot as shown is mounted on the lower end of the insulator 32 which is adapted to receive the enlargement 111 after it has traversed the distance between the opening 112 and the lower end of the dashpot. It is obvious that this dashpot may be embodied in a variety of forms. In the form illustrated I have shown it as a cupshaped member having a ings 117 'in the walls of the dashpot that the resistance offered to the passage of the enlargement 111 in the dashpot increases 1n proportion to the distance it has traversed from the lower end thereof. The mechanism shown by Fig. 2 for the final interruption of the circuit I have claimed in a divisional application, Serial No. 40,937, filed July 1, 1925.

It will be seen that by the structure above described I provide a self contained circuit breaking unit having but a single pair of current interrupting contacts. \Vhen employed on polyphase circuits one of these units will be employed in each phase of the circuit.

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

1. In a switch, the combination of a pair of cooperating contacts, a second pair of cooperating contacts arranged in series with said first pair, a third pair of cooperating contacts arranged in shunt to said first pair, resilient means tending to separate said latter contacts, latching means therefor, means effective successivelyto operate said first pair of contacts to open position and. to un latch said third pair of contacts for opening a circuit controlled by said switch and means independent of said first means elfective to operate said first and third pairs of contacts and subsequently said second pair of contacts to closed position for closing said circult.

2. A fluid break switch adapted for the control of a high powered circuit comprising a pair of relatively movable circuit opening contacts immersed in an insulating liquid, a pair.of relatively movable circuit closing contacts immersed in an insulating liquid and connected in series with said first contacts, independent contact. operating means comprising separate solenoids for each of said pairs of contacts and interlocking means for preventing the closing of the circuit closing contacts until after the closing of the circuit opening contacts and for preventing the separation of the circuit closing contacts until after separation of the circuit opening contacts.

3. An electric switch comprising relatively movable circuit closing contacts, relatively movable fluid break circuit opening contacts arranged in series therewith, means forming chambers for separately enclosing the respective opening and closing contacts, means for accelerating the opening movement of the opening contacts, separate latching means for retaining the opening and the closing contacts in closed circuit position, separate electromagnetic means for releasing the respective latching means, and a switch actuated by the opening. contacts for controlling the operation of the electromagnetic releasing means of the closing contacts whereby the circuit controlled by the switch is opened only by the opening eon tacts.

4. An electric switch comprising a pair of cooperating circuit opening contacts, a pair of cooperating circuit closing contacts arranged in series with said first pair, a third pair of cooperating auxiliary circuit open sponsive to a predetermined movement of mg contacts arranged in shunt with said said operating means for releasing said 10 first pair, a spring for accelerating the openlatch, said operating means being subseing movement of the auxiliary contacts, a quently operable to cause the opening of the latch for retaining the auxiliary contacts in closing contacts.

closed circifit position, switch operating In witness whereof, I have hereunto set means comprising a member arranged to my hand this 29th day of March, 1922. separate the opening contacts, means re- JOHN D. HILLIARD.

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