US1509758A - Electric switch - Google Patents

Description

Sept. 23 1924.

1,509,758 H. J. H. HUBER ELECTRIC SWITCH Filed Aug. 30. 1920 2 Sheets-Sheet 1 In ventor: Herman J. H. Huber,

His flttorneg.

Sept. 23 1924. 1,509,758

H. J. H. HUBER ELECTRI C SWITCH Filed 30. 1920 2, sheets-shape a e 6 egazege e Fig.5.

9 a o /35 e gags a e a e e 9 Fig.4

Inventor; Herman J. H. Huber;

His flttorneg.

Patented Sept. 23),. 1924,

all H. HUBER, SGIIENEGTADY, NEW YORK, ASSIGNQR- 130 G.

THIG Bi CUHPO'RATION OF NEW YQRE.

Application filed August 30, 191M). Serial No. teases.

To all whom may canoe-2%:

fie it known that l, {AN al i. He son, a citizen of the United, States, residing at Schenectedy', in the county of Schenectady,

State of New York, have invented certain new and useful Improvements in Electric Switches, of whiclithe following is a speci-' iication.

My invention relates to electric switches, particularly to those switches having contacts separable in insnlating fluid and has for its object to provide an electric switch which is an improvement in many particulars, to be described more in detail hereinafter, in similar vswitches heretofore known 7 in the art.

The novel features which I believe to be characteristic of invention will V definitely indicated in the claims appended fill hereto, while the features of construction and mode of operation will be understood by reference to the following description taken in connection with the accompanying drawings which show the preferred embodimentsof my invention and in which:

Figs 1 s. side elevation oi a triple pole switch embodying my invention; Fig. Qshows the switch mechanism embodying my novel form of energy storing means; 39 and Figs. 3, 4, 5 and 6 are views of detailed portions of the switch structure.

lIn Fig. 1 my invention is shown embodied in a triple poleor three unit switch, each unit comprising relatively movable coopersting contacts 1 and 2 separable beneath the surface of oil or similar insulating fluid contained in a vessel or tank 3. The contacts for each unit are controlled by mechanisms operative through a common mechanism 4. Enclosing the mechanisms for each unit is a. cover structure 5 to which are secured the oil vessels 3.

The mechanism controlling the switch. contacts forleach unit comprises, as shown in 4 Fig. 2, an actuating'lever or arm 6, which is preferably of wood for purposes of lightness and insulation, secured in a clam member 7. "ikfttached to the end of mem r 6 is a reciprocating rod 8 carrying the movable contacts 2, as bestshown in Fig. 1. For moving the end of arm 6 in a straight line, I provide a parallelmotion mechanism comprisinguszaralleling links 9 and 10 and a guide 11 secured to paralleling link 10 and movable about the fixed point 12.

Links 9 and 10 are connected. at one end to member G or clamp 7 and at the other end to a lever 13 which is movable about a fixed pivot .14. An 15 is also carried by pivot 14 and may be integrsl with lever 15. These arms 15 for each unit are connected by rods 16 whereby simultaneous movement of the mechanisms takes place. These separate mechanisms are controlled from a common opersting mechanism 4 which may be of the solenoid operating type, as shownin Fig. 1, or may be of the hand operated type as desired. By a proper interchange oiparts of mechanism 4, the stroke or extent of movement of the end of levers G can be varied over a wide range.

As the switch mechanism is necessarily rugged and heavy for switches of lar e rupturing capacity, I provide means faci itating the operation of the switch mechanism. As one portion of this means, I provide a means ior counterbalancing the weight of the mechanism which consists of a resilient or energy storing member 17 secured at cne'end to a, fixed support on the switch and connected at the other end to a bell-crank lever 18. The bell-crank is connected by means of an adjustable rod 19 to an extension 200i guide link 11 through a lost motion connection. The mechanisms for each unit of the switch are rovided with this balancing means, as siown in Fig. 2. With the movement of the switch to circuit openin position, the rod 19 is pulled up and bel crank 18 rotated clockwise to store energy in the spring 17. Due to the lost motion connection between rod 19 and extension 20, the switch mechanism moves freely during the first part of its opening movement and onl' functions to store energy in spring 17 uring the last part of its 0 ening movement. Cooperating with the on of bell crank 18 is an adjustable stop 21 adapted to limit the movement ofbell crank 18 when the switch is moved to circuit closing position. In order that energy may be stored in the spring at the proper part of the switch opening movement, un or varying lengths of stroke, I provide means for changing the oint of connection between extension 20 a the end of rod 19 and also provide two or more oints for the connection of springj'l and llcrank 18. Stop 21 is made adjustable for this same purpose.' It is thus apparent that de- Gil iii

tilt

end of lever r the stroke oi the mechanism, this means can be adjusted so that the spring 17 is tensioned at the proper part of switch opening movement. The mechanism can also be adjusted so that sutlicient energy is stored in spring i? to exert a force in switch closing direction substantally equal to the weight of the mechanism. "When the mechanism is, theretore, moved in circuit closing direction, the energy stored in spring 1? is delivered through hell cranh l8 and rod 19 to link 11 and enables the mechanism' to be moved with a minimum of etlort. A comparatively small closing force is therefore sutficient to operate the switch. The lost motion connection between extension and rod 19 is utilized. as a means for cutting oh the effect ct spring l? at a definite point in the switch closing movement.

it some provision is not made to prevent it, the energy stored in. spring 17 will be exerted to effect a rebounding action when the switch mechanisin'reaches the end of its response to the movement of the mechanism to circuit opening position. to engage an oil dash-pot or similar buffing means, not shown, to absorb the energy of the opening movement. in circuit closing direction. the butter arm 23 is shaped to engage lever 22 near the end of its path of travel and move circuit opening movement. it overcome this.

effect by the use of the bell crank 18. in the closed position of the switch as indicated by 2, that arm of the bell crank which is attached to the rod 19 makes a sharp angle with the rod while the other arm is substantially perpendicular to thev line of pull of the spring 17. The result is that as the switch is moved to open position and the bell crank is rocked in a clockwise direction, the eiitective length of the first mentioned arm increases while the eftective length of the other arm decreases. The combined effect of these changes in effective lengths of the two lever arms of this bell crank is to substantially compensate for-the increased tension of the spring 17 as it is stretched with the result that the switch is moved to open circuit position the tension at rod it after the\lost motion vhas been taken up remains substantially uniform. A further result is that when the switch has reached its open position the effective length of the one arm oi the bell oranlr is approximately a maximum while the eti'ective length of the other arm the arm to which the spring is connected, is so short that the eiiect of the spring tension on the switch may be ignored.

and rebounding of the switch will be of tectiveiy prevented.

The second energy storing means which is a part of each mechanism is a means for preventing overtra'vel of the mechanism in circuit closing direction. The sudden cessation ot movement of the mechanism must not cause an undue strain due to inertia and for purpose 1 provide a lever 22 in the path of movement oi: buder arm 23' carried by lever The louder arm acts in the lever about its pivot and against the tension exerted by a spring 24. This movement of lever 22 serves to retard the movement oi the mechanism quickly and to pre vent any overtravel with consequent strains on the mechanism.

The energy storing means associated with switch mechanism is a means for accelerating the opening movement of the mechanism. For this purpose, 1 provide an energy storing means in comnoon to the whole switch mechanism, as best shown in Fig. 2. This means consists of the energy storing or spring member 25 whichis connected at one end to the wall of the enclosure for the last unit or pole of the triple pole switch shown in Fig. 1. and is connected at the other end to the rod 16. The movement of the switch mechanism to circuit closing position operates rod 16 so that energy isstored in spring 25. This energy is delivered to the switch mechanism during its initial opening" movement to accelerate the mechanism. A lost motion connection is provided between the spring 25' and rod 16 in order to provide a free initial movement of the mechanism in circuit closing direction before tension is exerted on spring 25. a

in switches oi the character described. it is often advantageous to give a visual indication of whether the switch is opened or closed, particularly in the "form of switch shown in Fig. l in which the switch presents the same externalappearance in both open and closed positions. For this purpose it use an indicating means of the semaphore type which consists, as shown in Fig. 3, of a pivotally supported signal member having two projecting arms 31 and 32 substantially at right angles. Upon one arm is stamped the word open and upon the other arm the word closed. The arms may also be appropriatelypainted to indicate at a distance whether the switch is open or closed. The member 30 is pivoted within the enclosure of the end unit of the switch and is operated from the link 13 of the parallel motion mechanism through the connecting rod 33 and links 34-.

in Fig. 4 is shown another improved construction of my switch. in this figure, l have shown a means for cooling the arc gases formed asthe contacts separate and preventing the ejection of heated particles into the air chamber above the oil. For

this purpose it provide a baffling; member 35 convenience in assembling, three such sections being shown in Fig. 4. My baffling member comprises two plates provided with openin'gs36 in alignment and between the plates 'is mounted a wire mesh screen so that the openings 36 are screened. This structure is shown in Fig. 5 which is a plan view of ,one of the end sections.

The end sections of the member are secured to a plate 37 at the top of the oil vessel 3 by struts 38 and are spaced apart from the plate and inclined to correspond to the inclination of the terminal members- 39. Openings are provided in the end sections through which the terminal members 39 extend and the sections of the battling member are adapted to surround the terminal members at the ground sleeve thus acting in no way to cut down the striking distance for the arc. The central section of the bafiiing member is carried by a removable central plate 40 co-operating with the plates 37. This section is removable with the plate 40 to provide an opening through which a man can get into the oil vessel to align or properly investigate the contact structure. The bafiling' member 35 supported by the struts forms a rigid member. Having theend sections inclined, only the lower half of the sections are submerged in the oil, the upper half of each end section and the middle section being normally just above the level of the oil. When the contacts separate and are gases are formed within the oil, the oil volume immediately expands andthe oil level rises quickly, submerging the whole bafiling-member. The rise in level of the oil is in the nature of a slap which exerts considerable pressure. The bafliing member is rigidly supported to withstand this slap of the o1l, by the struts 38 and as the end sections are inclined, the oil pressure is progressively delivered as the oil level rises. The passa e of gases through the openings 36 of baing member 35 causes the gases to be broken up and cooled sufliciently so that they do not ignite the gaseous mixture in the 'space above the oil. Due to the wire screen, no highly heated particles can be ejected into the chamber. When the oil level subsides, the small space above the oil and beneath the bafile 35 is so rich in gases that it is noninflammable, so that even should heated particles or hot gases come in contact with these gases, they will not explode. This bafliing means for cooling the arc gases formed as the contacts separate and preventing the ejection of heated particles into the, air chamber above the oil is claimed per se in my divisional application, Serial No. 551,265, filed April 10, 1922, for electric switches.

In Fig. 6 is shown the lower end of one of the terminal members 39 carrying the fixed contacts 1 which in the form shown comprises a pair of laminated contact fingers 41 to which are secured the guide fingers 42. Co-operating with the fixed contact fingers 41 are the movable contact members 2 wedge-shaped in configuration and carried at one end of the reciprocating rod 8. As the movable contact members 2 are moved into and out of engagement with the fixed contacts, it often occurs that due to slight changes in adjustment the wedge-shaped member as it moves into contact engaging position will strike one of the guide fingers 42 bending it over and causing considerable damage making a poor contact and throwing the mechanism out of order. This condition is effectively overcome by providing means for guiding the movable contacts into proper engagement with the fixed contacts and protecting the guide fingers 42. For this purpose cam members 43 are ivotally supported by shoulders 44 rigldly carried by extensions 45 supported by the terminal members 39. These cam members 43 are so located relatively to the ends of guide fingers 42' and loosely pivoted to shoulders 44 that should the wedge-shaped movable contact 2 move out of alignment, it will strike one of the cam fingers 43 and be guided into its Ipgoper path without impairing the guide gers 42.

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

1. In an electric switch, the combination with relatively movable cooperating contacts, of a mechanism controlling said contacts, means cooperating withfsaid mechanism to prevent overtravel of said mechanism in circuit closing direction, means for accelerating the movement of said mechanism in switch opening direction, and means exerting a force on said mechanism in switch closing direction substantially equal to the weight of said mechanism.

2. In an electric switch, the combination with relatively movable cooperating contacts, of a mechanism for controlling said contacts, means for exerting a force on said mechanism in switch closing direction substantially equal to the weight of said mechanecting the other end of said lever to said mechanism.

3. In an electric switch, the combination with relatively movable cooperating contacts, of a mechanism for controlling said contacts, a device in which energy is stored by the circuit opening movement of said mechanism, and means intermediate said device and said mechanism operative to revent rebounding of said mechanism w en reaching circuit opening position.

4. In an electric switch, the combination with relatively movable cooperating .contacts, of a mechanism for controlling sald contacts, a spring adapted to be tensioned in response to the circuit opening movement of said mechanism, a bell crank lever connected to said mechanism and to said spring arranged to exert a uniforimforce on said spring during the circuit opening movement, and means whereby the tensioning of said spring can be adjusted to exert a force in circuit closing direction substantially equal to the weight of said mechanism.

5. In an electric switch, the combination with relatively movable cooperating con tacts, of a mechanism for controlling said contacts adapted to operate with varying lengths of stroke, energy-storing means operative in response to the circuit opening movement of said mechanism to exert a force in the circuit closing direction substantially equal to the weight of said mechanism, means for preventing rebounding of said mechanism from the open circuit position, and means whereby the energy stored in said energy-storing means may be varied to correspond to the stroke of the mechamsmo weaves 6. In an electric switch, the combination -with relatively movable cooperating contact's, of a mechanism for controlling said contacts, including an operating arm, an energy-absorbing means, and a member carried-by said arm adapted to operatively engage said means to prevent overtravel of said arm when moving in the circuit closing direction, and a second means in which energy 'is stored during the latter part of the switch closing movement to accelerate the opening movement of the switch 7. In an electric switch, the combination with relatively movable cooperating contacts, of a mechanism for moving said contacts me straight line including a guide link, an extension to said link, an ener storing device, and a bell-crank adjusta y secured to said extension through a lost motion connection and connected to said energy-storing device operative in response to the final switch opening movement to store energy in said device and prevent rebounding of said contacts.

In witness whereof, I have hereunto set my hand this 20th day of Au t, 1920.

-ERMAN J. HUBER.

Images