US2489070A - Knife blade or plug type electric switch - Google Patents

Description

Nov. 22, 1949 c. A. ANDERSON KNIFE BLADE OR PLUG TYPE ELECTRIC SWITCH 2 Sheets-Sheet 1 Filed July 18, 1946 jzzleizj arx Qarwza'e j /adm'saw c. A. ANDERSON 2,489,070

KNIFE BLADE OR PLUG TYPE ELECTRIC SWITCH 2 Sheets-Sheet 2 Nov; 22, 1949 Filed July 18, 1946 ,Jiawezzfor: yam/ 7506 fzzakrsozz/ Patented Nov. 22, 1949 UNITED STAT ES; PATENT OFFICE.

KNIFE BLADE OR. PLUG TYPE ELECTRIC SWITCH Clarence A. Anderson, San Diego, Calif.

ApplicationJuly: 18;. 1945,, Serial No. 684,576

7 Claims.

My invention, relates toelectric switches of the knife type and as illustrated. and described: comprises a single throw double: pole knife switch although the: invention is. readily adapted to. a single: pole.- switch.

The primary object of my inventionis, the provision of a switch in which the'connectin elements are placed under tension when the circuit is closed, thereby insuring a close and tight connection between all of the conducting parts of the switch with a minimum of resistance and less likelihood of arcing developing in the use of the switch.

Another and further object of my invention. is the provision of duplicate. contact means at one end of the knife forming the. connecting element between the. terminals of the. switch so that ifv for any reason one set of parts does not. function properly to insure the flow of electric current therethrough, the other connection will operate to provide this function.

Another and further object of my invention is the provision of a switch in which the various operating parts, being under tension in their closed position, as they are moved the surfaces are wiped clean and dirt cannot lodge between the contact points thereby causing an interrup-- tion in the-circuit or interfere with the free flow of electricity therethrough.

Another and further object of myinvention is the provision of a switch which in normal closed position is in dead center alignment; but upon the initial and very slight movement of" the switch lever to open position the switch lever is thrown off center, and due to the tension theswitch lever is automatically thrown clear of the connecting points thereby lessening the danger' of arcing which ofttimes results when these switches are opened and sometimes severely burns the operator of the switch.

These and other objects of my invention will be more fully and better understood by reference to the accompanying drawings and in which:

Figure 1 is a top plan view of my improved switch;

Figure 2 is a sectional viewon linev 22' of Figure, 1 showing the switch in closed position;

Figure 3 is an end elevational View of the. switch;

Figure 4 is a sectional view on line 2-2 of Figure 1 showing the switch in open position; and

Figure 5 is a cross-sectionalview on lines. 5-51 of Figure 1.

Referring now specifically to the drawings and. in which like reference characters refer. to-

extending outwardly therethrough within which screws l6, iii are mounted by means of which the usual electrical conductors such as wires; cables. or the like can be. connected;

Screws ii, ll are provided which have. their heads mounted. on the underside of the base In in a recess l8 and extend upward therethrough.

into the bases of each of the members. H and I2: andxprovidez means by whichthe members II. and I2 are firmly fixed. tothe base member l0:

Extending upward from the bases of each of\ the members H and I2 are. side members t9 ami 2a, which; converge inwardly towards each other; at their: outenor free ends and have knife members..2'.l,.2.l of a: connecting member pivotallymounted therein upon pins 22., 22 which have enlarged. heads 23' and: 24'; on each endthereof,

both the side contacts of the side members 1 9 and 20- with the knife 2! of the pins 22, 22 through the knife 21"- and the connections being fairly snug, although not sufiiciently tight to prevent the movement of the knife members 2|, 2-! upon the pins 22, 22 as a pivotal axis.

A nonconductor 25 is provided which connects the knife members 21, 2| and into which the ends of the knife blades 2!, 2i extend, each of these knife members 2|, 2! having semicircular conductors 26;, 26 mounted. therein transversely thereof'with their ends projecting outward. from the knife members 2'1, 2!. with flat faces which contact against the nonconductor member 25,. with bolts 2T, 2'! extending through the nonconductor 25" and. through the semi-circu1ar conductors 26,16, thereby connecting the member 25 firmly to the, ends ofthe members 2|, 21 whichextend into recesses 28, 28 formed in the. side of the nonconducting member 25. A handle 29 is secured by meansof a bolt as, to the nonconductor 25. by. means of which the switch is opened. and; closed. by the operator as may be desired.

Mountedin:v recesses 3L3! by means of screws 32,, 3-2. the: heads. of which are within the recess 65 I8 formedontheunderside. of the. base member.

l, are elongated flat spring base portions 33, 33 of stirrup shaped connecting members 34 and 35 in the opposite end of the base [B from the connecting members I l and I2 heretofore described. Each of these members 34 and 35 in addition to the base portions 33, 33 have inwardly converging side Walls with rollers 35, 36 mounted on the upper ends of each side wall of each member 34 and 35 by means of bolts 3'1, 37. these bolts having enlarged heads 38, 38 spaced apart from each other a slightly lesser distance than the thickness of the knife members 2!, 25, so that as the switch is closed the knife members spread the arms of each of the members 3 5 and 35 thereby insuring close contact with the sides of the knife members 2 1, 2| as is usual with switches of this type.

The base portions 33, 33 of the members 34 and 35 have flat spring elongated portions extending therefrom through the ends of which the bolts 32, 32 extend the point of attachment of the base portions 33, 33 to the member It) being offset with respect to the vertical plane through the members 34 and 35 and the axis of the rollers 35, 33. The outer periphery of the rollers 35, 33 extends into the path of travel of the outer periphery of the semicircular members 26, as the knife members 2i, 2! are placed in closed position so that as the switch is placed to final closed position the rollers 33, 3t rotate pushing the members 34 and slightly out of the vertical position (Figure 2) so that an electrical connection is made between the rollers 35, 33 of the members 26 secured in the ends of the blades 2|, thereby tending to push the arms 34 and 35 toward the arms II and I2 at the opposite end of the member, placing all of the connecting portions of the switch under tension.

Connecting ears 33, 39 having screws 43, 48 therein with the members 39, 39 being connected to the bases 33, 33 provide terminal means to which electrical wires or the like may be secured for electrical conducting purposes.

A stop block ii is mounted on the base member I3 against which the handle 29 rests when in closed position, in which position the centers of the blade members 2!. 2i and the handle 29, the axes of the bolts 22 and 37, 3'! together with the contact point of the members 25, 26 with the rollers 36 are all in alignment, or in eifect a dead center position in which position the switch will remain until force is exerted on the handle towards opening the switch, and then due to the force exerted through the spring base members 33, 33 the knife portions will be quickly thrown clear of the heads of the bolts 38, 38 and the members 23 thrown clear of the rollers 33, 36 thereby quickly and efiectively breaking the circuit and lessening the danger of arcin when these switches are used with high voltage circuits on switchboards and the like.

From the foregoing description it is believed that the operation of the switch will be readily and quickly understood in that the switch is put into position on a switchboard terminal box or the like and connected through the terminals with the proper wiring leading to the sections of electrical power on the one side and to the light circuit or the like on the other.

Upon the handle being pushed into closed position the blades 2], 2i frictionally engage between the heads 38, 38 on the bolts 31 normally securing contact. As the rollers 35, 36 engage the rounded surfaces of the members 26, 26 and the switch is closed members 34, 35 are canted slightly out of vertical position producing a slightly wiping action on the outer surfaces of the knives 2|, 2| and creating a lateral thrust towards the handle 29 on the knives 2|, 2i thereby placing the whole structure under tension and taking up any wear or looseness in any of the operating parts and insuring a tight connection for the operating parts of the switch. As these switches are used, the constant bringing together of these parts keeps the surfaces clean and no carbonizing can result and the operation of the switches is always certain.

When it is desired to open them, the handle is grasped by the operator and pulled out in the usual manner and as explained above, when the blades are in dead center position the switch automatically kicks out because of the tension thereby lessening the danger of arcing or burning of the operatior and making the switch easy and quick to operate.

While I have described more or less precisely the details of construction, I do not wish to be understood as limiting myself thereto, as I contemplate changes in form and the proportion of parts and the substitution of equivalents as circumstances may suggest or render expedient without departing from the spirit or scope of my invention.

What is claimed is:

1. An electric switch comprising in combination a non-electrical conductor base, a combined terminal and mounting for a movable connector, a movable connecting member pivotally mounted on said combined terminal and mounting, a second mounting and connector having a spring base mounted on said base having spaced contact portions and rollers movably mounted thereon, and a second connector mounted on the pivotally mounted connecting member adapted to engage the said rollers thereby placing the moving parts of the switch under tension.

2. An electric switch comprising in combination a non-electrical conducting base, a mounting for a connector mounted thereon, a connector movably positioned on said mounting, a second mounting member having spaced contact members thereon, rollers on said contact members, a spring member on which said second mounting member is positioned secured to said base and a contact member secured to said connector for engagement with the said rollers whereb a plurality of contacts is established with the connector and the mountings and connector are placed under tension.

.3. An electric switch comprising in combination a non-conductor base, a fixed terminal on said base, a connector pivotally mounted on said fixed terminal, a second terminal having a spring base portion, a stirrup shaped connecting link thereon having rollers at its free end, a member on the free end of the pivotall mounted connector for engagement with the periphery of the rollers on the stirrup shaped connector, and a handle on the pivotally mounted connector, the rollers on the stirrup shaped connector extending into the path of the member on the free end of the pivotally mounted connector whereby when the switch is closed the connecting members are placed under tension.

4. An electric switch comprising in combination a non-electrical base member, a connector mounted thereon, a pivotally mounted switch member on said connector, a second connector having spaced free ends mounted on a spring base on the said base member, rollers on the free ends of the said second connector, a handle secured to the free end of the switch member and '5 a connector secured to the said handle and to the free end of the switch member having a rounded outer surface adapted to engage the rollers on the second connector and place connecting parts under tension when the switch is closed.

5. An electric switch comprising in combination a non-electrical base member, a connector mounted thereon, a pivotally mounted switch member on said connector, a second connector having spaced free ends mounted on a spring base on the said base member, rollers on the free ends of the said second connector, a handle secured to the free end of the switch member and a connector secured to the said handle and to the free end of the switch member having a rounded outer surface adapted to engage the rollers on the second connector and place connecting parts under tension when the switch is closed, the centers of the mounting for the switch member, the rollers and the center of the rounded outer surface of the connector on the handle being in alignment When the switch is closed.

6. An electric switch comprising in combination a non-electrical base member, a connector mounted thereon, a pivotally mounted switch member on said connector, a second connector having spaced free ends mounted on a spring base on the said base member, rollers on the free ends of the said second connector, a handle secured to the free end of the switch member and a connector secured to the said handle and to the free end of the switch member having a rounded outer surface adapted to engage the rollers on the second connector and place connecting parts under tension when the switch is closed and a limit stop adapted to engage the handle portion of the switch member.

7. An electric switch comprising in combination a non-electrical base member, a connector mounted thereon, a pivotally mounted switch member on said connector, a second connector having spaced free ends mounted on a spring base on the said base member, rollers on the free ends of the said second connector, a handle secured to the free end of the switch member and a connector secured to the said handle and to the free end of the switch member having a rounded outer surface adapted to engage the rollers on the second connector and place connecting parts under tension when the switch is closed, the centers of the mounting for the switch member, the rollers and the center of the rounded outer surface of the connector on the handle being in alignment when the switch is closed and a limit stop adapted to engage the handle portion of the switch member.

CLARENCE A. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 477,374 Klein June 21, 1892 765,609 Badeau July 19, 1904 881,686 Hoadley Mar. 10, 1908 905,782 Barnum Dec. 1, 1908

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