US976654A - Electrical switch. - Google Patents

Description

J. D.`,H1LLIARD. ELECTRICAL SWITCH. APPLICATION FILED JULY l8,1907.

Patented Nov. 22, 1910.

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UNITED srariis PATNT onirica.

JOHN I). HILLIARD, 0F ALBANY, NEW'YRK.

ELECTRICAL SWITCH.

To all whom it may concern:

Be it known that I, JOHN D. HiLLiARD, a citizen of the United States, residing at -\.lbany, in the county of Albany and yState of Newv York, have invented certain new and useful y Improvements in Electrical Switches, of which the following isa specification, reference being had therein to the accompanying drawing.

My invention relates to switches for highpower circuits and especially to what are known as oil break switches, wherein the arc is rendered automatically self-extin- In switches of this type heretofore employed, the oil pot has had its interior divided into two separate chambersY with a passageway between them through which the movable terminal mustl pass to rengage the liXed terminal inone `of the chambers. Vhen the circuit is broken, pressure in this chamber due to the arc causes expulsion of the oil through the passageway, and as the movable terminal is withdrawn, the arc is not only constricted, but is finally destroyed by the oil jet.

The principal object of the present invention is to provide means tor absorbing the shock due to the initial formation of gases and consequent pressure on the walls of the chamber containing the fixed electrode, so as lto lessen the liabilityof rupturing the walls of the oil pot and consequent destruction of the switch. To this end I provide an oil pot with two chambers, one of which contains a fixed electrode and has walls expansible in response to the initial pressure generated within it. Stated in concrete terms of a single embodiment, the oil pot may have its interior divided into two cham' bers by means of a movable diaphragm or cup, which is the specific t'orm I sha-ll here in illustrate andudescribe.

Other forms based on the same principle will readily occur to those skilled in the art,

all of'which I wish to include within the scope of my present claims.A

My -invention is illustrated as to the speciic embodiment stated in the accompanyng `drawing wherein- *igure l is a section of a single unit, and

,Fig 2 is a similar section of a connected pair of units forming one poleof a complete switch. f-

YReferring to the drawing, and especially to\Fig. 1, A is the body of the oil pot vhav- Speccation of Letters Patent.

`complete interior lining o Patented Nov. 22, 1910.

. Application led July 26, 1907. Serial No. $185,720.

ing end caps a and a', the former provided with vents a2 and a central threaded opening as which receives the domed insulator e* around which a ring of Babbitt metal a5 is inserted. In the crown of the dome a small' ringe7 of Babbitt metal is inserted surrounding an insulating tube a at the upper end of which I locate a stuliing boX a8 through which and through the tube passes the movable Contact terminal T. Thecap a has a central opening in which is seated an insulator a9 carrying the fixed .terminal T which is provided with contact jaws or sockets t for the reception of the end of the movable terminal T.

The interior of the oil pot is divided into two chambers C and C by means of an inverted cup D, having cylindrical side walls of a diameter somewhat less than the Ainternal diameter of the oil pot, and a transverse bottom constituting a diaphragm d. This diaphragm is provided with a small Vent d', and a large central opening cl2 through which ashouldered insulator I is insertedso as to have its head within the cup, thus preventing its displacement by the pressure therein. This insulator may advantageously be made of porcelain set in a bushing of Babbitt metal and lined with a wooden or liber tube z' which protects the porcelain from injurious effects of the arc and is shouldered at its lower end as shown at z" to prevent its being blown through the insulator. The cup D is rovided with a tp insulation, and the cap a is internally insulated by'means vof a disk of similar material. The cup 1tself is preferably formed o f steel and normally rests by gravity in the .position shown in Fig. 1. l/Vhen pressure is generated in the chamber C, the cup rises through a predetermineddistance, until it meets the metal sto ring or liner al inserted from the top o the oil pot. By .properly placing this limiting stop,ithe travel of the cup may be regulated so as to give the exact mitral relief required and thereafter-.to maintain` the diaphragm D and insulation in fixed position, so that further relief from pressure in the chamber C can only be afforded by the'- continued ejection of oil therefrom the oil may be discharged. The cap a of each unit is omitted in this form and instead of the dome a4 I provide a guide for each movable contact consisting of an insulator ato supported in a bracket or bridge @41. These guides may be located in any convenient position. yThe movable contacts T-T are connected through the yoke T2 movable from-without the casing by means of a wooden operating rod R. As the operating mechanism forms vno part of the present invention, it will be understood that the form thereof shown is used for convenience only and that any suitable actuating means may be substituted. Y

The casing- A containing the operating yoke and inclosing the movable terminals is made high enough to permit the raising and lowering ofthe parts to open and close the switch without ever connecting the casing to any part of the circuit. By this means and by the proper use of insulators as shown, no exposed part of the switch is energized or alive at any time,vwhether it be open or closed. This is a matter of importance, as it insures the safety of the operators who have heretofore been exposed to imminent danger of injury or death by reason of the switch casings and oil pots being commonly connected directly to vone or the other of the circuit terminals.

The operation of this improved switch is as follows: The contact rod T being in the position shown in Fig. 1, the circuit is open. To close it the rod is directed down until its top reaches the socket t, the rod then eX- tending through the passageway in the tube i, and the cup D remaining in the position shown. In opening the switch, the rod T is drawn quickly upward. The instant the tip leaves the socket t, an arc is formed between the contacts in` the chamber C, and high pressure is created therein due to the arc gases. The volume and pressure of the gas depend upon the amount of energy broken, and whether the arc is broken in a space of greater or less capacity, or in other Words the law of gases holds true that pressure volume content. Vith an immovable diaphragm and no cushion space in the chamber, the pressure would be enormous because the volume of gas would be kept extremely small, having no chance to expand. By means of the central passageway z' in the diaphragm this pressure may be somewhat reduced because there is an opportunity for the oil to escapeand for the gas to expand. With the present arrangement, however, the cup rises as soon as pressure is generated, until it reaches the stop al".

The continued upward travel of the rod T draws the arc through the tube z' so that it becomes constricted therein. The oil rushing from the chamber C into the tube is con centrated into the path of the arc, rupturlng the latter either before or after ythe rod leaves the upper end of the tube, according to the conditions prevailing in the circuit.

It will be understood that while I have shown an opening d in the diaphragm, the amount of oil which is driven through this opening` when the arc is sprung. under pressure of the expanding gasesris an almost negligibleouantity and that practically all of the oil which is driven from the chamber is forced through the tube i to effect the breaking of the arc. This is an important feature in my device, heilig a distinct improvement over certain forms of oil switches in which there is a diaphragm having a large number of holes through which the oil escapes at the first rush of the expanding gases instead of being forced into a central tube where it can be utilized to break the arc. In Fig. l the cup D is shown as being spaced from the sides of the vessel A. This is for the purpose of illustration. In practice the cup would fit somewhat closelyto the inner sides of the larger vessel. y

IVhile I have shown the oil pot as provided with an insulator L4 in connection with the cap a, it will be apparent that as far as the operation of the switch itself is concerned it-would work equally well if the rod passed through the cap without any msulating means, the object of the insulator l being to prevent the outer surface of the pot from formingpart of a circuit and thereby endangering the operator.

The insulating piece ai in Fig. 2, might also be dispensed with and the rod T be -guided by the member an.

Other changes may suggest themselves to those skilled in the art, and I do not wish to be limited therefore to the specific construction herein described. The gist of my invention lies inproviding an oil switch of the general type shown with movable portions, walls, or partitions, forming an arc chamber which will `be automatically enlarged or expanded when under heavy pressure, to relieve the initial strain on the surrounding parts. This provision being made, I contemplate all such non-essential changes and modifications of design as fairly fall within the scope 0f the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Pat ent is:

l. In an electrical switch, a containing'vessel, movable means dividing the interior of said vessel into two chambers one of which is normally closed and constitutes a. pressure chamber, Vinsulating liquid in both chambers, and contact terminals arranged so as to be brought together in the pressure chamber and separated through an opening in said movable means, whereby initialpressure due to the arc is relieved but will subsequently act to destroy4 the arc.

2. In an electrical switch, a. fixed and a movable terminal, means forming a pressure chamber around said terminals when closed, said means having an opening in the path of the arc formed on breaking, and adapted to yield topressure in the chamber so as to enlarge the same upon the first formation of the arc and thereafter to restrain the pressure anddirect oil through the opening into the path of the arc whereby a large amount of energy may be interrupted without danger to the switch. y

3. ln an electrical switch, movable means forming` an expansible pressure chamber,

-terminal contacts adapted to be closed and opened therein, and insulating iuid in said chamber, said movable means having apassageway for the vmovable terminal within which the arc is constricted, and at the same time exposed to the pressure created by itself in the chamber.

4. In an electrical switch, fixed and movable elements forming a pressure chamber, a fixed terminal seated in said chamber, a cooperating movable terminal adapted to be inserted in and withdrawn from the cham- -ber in making and breaking thel circuit, a stop for limiting the travel of themovablel element, and means carried on said element to restrict the arc formed upon breaking and to direct the arc pressure in the chamber into the path of the arc to extinguish the same.

5. In an electrical switch, an oil pot containing oil, `a fixed terminal seated beneath the oil, a movable diaphragm dividing the interior of the pot into two chambers beneath the oil, said diaphragm provided with an insulated opening, and a movable terminal adapted to pass through said opening in engaging or disengaging the fixed terminal.

6. An oil switch comprising a containing pot of metal adapted to withstand high pressure, a fixed terminal seated in the bottom of said pot and insulated therefrom, oil partially filling the pot, an inverted metal cup within the pot above the fixed terminal, an insulating tube through the bottom of said cup, and a movable terminal passing through insulation in the top of the Oil pot and adapted to pass beneath the oil through said tube into the cup in closing, and the reverse in opening the switch.

7. An electrical switch comprising a steel oil pot, a fixed terminal seated in the bottom thereof but insulated therefrom, a'movable terminalentering the top of the pot but insulated therefrom, a movable inverted vented steel cup in the pot formingv a pressure vchamber about the fixed terminal, and an insulating bushing set in the bottom of said cu with its opening in line with the termina s, whereby pressure due to the are formed movement of the cup, the arc will be extinguished by the outrush of oil from said bushing, and the gases may escape from the cup and the oil return thereto.

S. An electrical switch comprising an oil pot containing oil, a fixed and a movable terminal, a movable diaphragm dividing the interior of the pot beneath the oil so as to iorm a pressure chamber for the terminals and having an opening for the passage ot' the movable terminal and a stop to limitthe movement of' said diaphragm, whereby the oil under pressure due to the arc gases will be directed against the arc to extinguish the same.

9. An electrical switch comprising a metal. oil pot, a yielding metal partition Vor diaphragm in the pot beneath the oil, fixed and movable terminals adapted to be separated in they pot at one side of and through the diaphragm, and means` to insulate said terminals and their connected parts from the pot and the diaphragm at all times whatever the condition ofthe switch.

10. An electrical switch comprising a pair of open-ended oil pots containing oil, a fixed contact in the bottom of each pot, a connected pair of movable contacts adapted to bridge the fixed contacts from one pot to the other, means in each pot for directing oil under pressure into the path of the arc to 'extinguish it, and means common to both pots for receiving the oil ejected therefrom and returning it thereto.

11. An electrical switch comprising an oil pot with rigid walls, a movable element adapted to rise under the influence of pressure in the pot and to fall by force of gravity, means for limiting the extent o" such rise and fall, a fixed terminal seated in the expansible chamber inclosed by the movable element, a movable terminal adapted to pass into and out of said chamber in closing and opening the circuit respectively, and means carried by said movable element to restrict the arc formed between the terminals uponv breaking, and to direct the arc created pressure in the chamber into the path of' the arc while restricted to extinguish the same.

12. An electrical switch comprising an 011.

` pot with rigid walls, oil in said pot, a fixed terminal seated beneath the oil, a movable terminal with suflicient travel to produce an attenuated arc on breaking, and a movable element in the oil pot forming a pressure chamber around the terminals when they are closed together, but lying in a plane intersecting the path of the aro between the terminals when they are separated, and adapted to direct oil underr pressure due to the arc into the path of the arc to extinguish the same. v I

13. An electrical switch comprising an oil pot having an opening, a fixed terminal within the pot, a Inova' e termlnal working through said opening, and an auxiliary oil receiving vessel surrounding the movable electrode and covering said opening so as to receive the oilejected therefrom and return it thereto.

M. An electrical switch comprising a pair of open-ended oil pots, a pair of fixed terminals therein, a pair of yoke connected movable terminals Working through the open ends of the pots, and an auxiliary oil vessel surrounding the movable terminals and covering the openings in both pots, so as to' receive oil ejected therefrom and return the same thereto.

15. An electrical switch comprising a pair of cylindrical oil pots set apart with their axes parallel and their upper ends open, a

pair of fixed terminals seated in the bottoms of-said pots, a pair of yoke connected movable terminals adapted to bridge across the fixed terminals through the open ends of the pots7 and a casing bridged across the upper ends of the pots, with openings in its bottom registering with the openings of the pots, said bottom being raised between the pots to insure drainage thereinto of oil ejected into the casingwhen the switch is opened.

In testimony whereof I affix my signature in presence of tWo Witnesses.

JOHN D. HILLIARD.

Witnesses:

y CHARLES E. PARSONS,

M. L. STEVER.

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