US1040455A - Electric-switch contact. - Google Patents

Description

Witnesses L. L. TATUM. ELECTRIC SWITCH CONTACT.` APPLIATION FILED AUG. 27, 1907.

Patend 0c.8,1912.

` Contacts, of which the following isa full,

great, the oil film which occurs between the recesses formed in the contact faces, the oil -secured between the contact faces, whereby UNITED STATES PATENT @il llhl.

LEWIS L. TATUM, 0F MILWAUKEE, WISCONSIN, .ASSIGNOR TO THE CUTLER-HAMMER MFG. CO., 0F MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

To all Iwhom, it may concern:

Be it known that I, LEWIS 'L. TATUM, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented-new and'- useful Improvements in Electric-Switch clear, concise, and exact description, reference being had to the accompanying drawf in forming a part of lthis specification.

y invention relates to improvements in electric switches and particularly to contacts for such switches. It applies particu larly to switches in which the contacts are immersed in oil.

Heretofore the faces of the switch have been smooth 'and when the contacts werey brought into engagement, a thin film of oil, remained between the same, thereby causing' a high resista-nce contact. Due to this fact arcs formed which burned the contacts andy caused them to deteriorate. One of the objects of my invention is to, form the contacts of a switch'in 'such a manner that when the contacts are moved into'l engagement the oil film will be practicallyf eliminated.

In accordance with the preferred form of my invention, I vprovide recesses in the contact -face of at least one of the contacts. Due to this construction when the contacts are brought into engagement the oil which may be between the contacting faces. is squeezed or rubbed from between the faces and into the recesses, thereby eliminating the oil film, which has previously existed between the contacts.

When the contact faces are made smooth as has been previously done, owing to the fact that the crea of the contact faces is so contact faces could not be squeezed or rubbed out. By my construction, duc to the Hlm which tends to form between the contact portions or contact faces of the contacts may be readily squeezed or rubbed into the recesses. Accordingly a close engagement is the current will be carried better than in the old form of contact, and arcs will be eliminated during the engagement of the contacts.

For the purpose of disclosing my invcntion, I have illustrated in the accompany- .ing drawing, one embodiment thereof.

Specification o! Letters Patent.

Application led August 27,

rnrenteaoee. s, 1ere. 1907. Serial No. 390,399.

cordance with my invention, the oil easing of said switch beingf shown in Section. Fig. f2 is an underside view of the stationary arcmg contact, and Fig. 3 is a plan view of the moving arcing contact.

Although .I have illustrated in the accompanying n rawing for the purpose of disclosing my invention, one use of the same, it will be undeistood that the invention may be applied in various other capacities'.

ln the electromagnetic switch illustrated, .l preferably provide an alternatinw current magnet having a frame 1, in whidli is'supported the usual electro-magnetic Winding 2. This frame is supported upon a cover or head 3 having upwardly extending lugs 4, by which it is adapted to be attached to any suitable base.

The switch parts are all mounted beneath the cover or head 3, upon 'an insulating block 5 which depends from the cover or head 3, and is secured thereto by vsuitable bolts 6. The movable member of thebwitch is mounted upon a stationary terminal member 7 secured to the insulating block 5b a bolt 8, and having a suitable terminal socliet 9 provided with screws 10, into which is adapted to tit the end ot' one of the conductors. The movable member of the switch comprises a main contacter brush 11, an auxiliary contact 'l2 and an arcinplr contact 13. rlhe main Contact is slightly flexible so that, when it engages the stationary contact member of the switch, it will rub over the contact plate, and is preferably made of laminations or leaves Jfastened in a cup 14.

The auxiliary contact is preferably mounted upon a flexible or spring arm l5, and takes the form of a .roller 16 adapted to make u rolling engagement with the cont-act plate.

The arcing Contact 1,3 is preferably pivotedV upon a spring arm 1 8 which, when the switch is open rests against a stop or plate 19,Which prevents the arcing contact from coming into engagement lwith the auxiliary contact. The main contact ll, the arm 15, the plate lll, and the arm 18 are preferably carried upon an arm 20, pivoted upon the support.

7, and are clamped iu position upon said pivotcd arm by means of a nut 2l. In order that the arm lll may be relieved of. carrying current which would tend to deteriorate the Sti titl

spring thereof, lt provide e 14 and the arcing contact 3 3, and which is adapted to carry the current. The pivoted arm 2O is provided with an upwardly extending member gilt, adapted to pass through a central opening 5t cut in the oloclt 5, and be pivotally connected to a link 23, which at its opposite end is pivotally connected with the core Q4 of the solenoid 2. Thus when ythe solenoid winding is energized, the arm. 20 will be raised and will carry with it the various movable contacts of the sa/itcl'in Ylhe Ystationary contact of the switch cornprises a stationary Contact plate 25, having a terminal socket 26 similar to the terminal socket 9, and provided with a removable arcing Contact plate This arcirig eontact plate is preferably secured in position by 'means of a clamp 27, and is adapted to be engaged by the arc-.ing contact i3.

lThe various contacts are all inclosed in an oil casing 28, which is secured to the casing head 3 by suitable screws Q9 which are con- `nected to the casing and extend through the head, nuts 3# being; provided on the screws to maintain the casing in position. The casingl is lled with oil whereby all of the contacts operate in an oil bath.

lt has been found that, where switch contact's which operate in oil have the faces there of comparatively smooth, an oil lihn forms between the faces, thereby causing a high resistance Contact and tending to form arcs which burn and cause the deterioration of .the contacts. l have therefore provided the 'arcing' contact 13 and the arcing Contact plate 26a With recesses or slots 3l, which extenddiagonally across the faces oit the members, whereby as the two members en gage, the film oioil may be readily pressed into these recesses, permitting a clean contact to be made. ln practice, l prefer to have the grooves in one contact so disposed that they will intersect the grooves iii the other contact, and have so villustrated the same.

While l have described the recesses as being formed in the arcing contacts it will be understood that like recesses may he fieaible com doctor 5,22, which extends ,hetween'the cup' i meeste two Contact members Wherever Whether they form termed :in desired, irrespective of areing or rhein contacts.

Having thus described l claim. as new and desire ters Patent, is:

l. A pair of coperatingswitch contacts each havinga rigidcontact face with a plurality et grooves therein, the grooves in one Contact extending angularly to the grooves in the other contact.

2. A pair of cooperating switch contact-s each 'provided with rigid contact tace having a plurality of diagonally disposed grooves, the grooves in one Contact being disposed to intersect the grooves in the other Contact.

3. laan oil vimmersed switch, cooperating switch contacts, the engaging face oi' one of said contacts comprising a plurality of substantially parallel rigid ribs spaced to forni open ended channels for conveying the oil away from lthe engaging-faces of said contacts when brought together 4i. Av pair of cooperating switch contacts the engaging surface of each Contact com` prising a plurality 'of rigid uninterrupted ribs spaced from one another throughout their entire length, the ribs of one contact extending at an angle to the ribs oit the other contact.

5, in an oil immersed switch, cooperating contacts, one ot' said contacts having one or more grooves therein for conveying theoil away trom the engaging faces of said contacts when the switch is operated,

t3.- ln an 4oil immersed switch, co fontacts each provided with a rigi contact face having,- one or` more grooves formed therein for conveying the oil away from. the

my invention, what to secure by Leterating engaging faces o saidv contacts when the switch is operated.

ln Witness whereof, scribed my naine in the presence of two Witnessest Lewis L. 'rs'roit l have hereunto sub-

Images