US1485192A - Electric switch - Google Patents

Description

Feb. 26 1924. 1,485,192

w. L. KUBACH ELECTRIC SWIT'CH FiledAug. 29. 1922 Flgl.

I \A/illi am L. Kubach Patented Feb. 26, 1924.

UNITED STATES 1,485,192 PATENT OFFICE.

WILLIAM L. KUBACH, OF CLEVELAND, OHIO, ASSIGNOB TO GENERAL EIiECTRIC COM- PANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application filed August 29, 1922. Serial No. 584,952.

To all 107107)), it n'uz concern:

Be it known that I, V ILLIAM L. KUnAoH,

a citizen of the United States, residing at leveland, in the county of Cuyahoga, State of Ohio, have invented certain new and use tut Improvements in Electric Switches, of

which the following is a specification.

My invention relates to electric switches, and an object of my invention is to provide an improved and simple construction and arrangement of the circuit controllingme1n her of an electric switch such that arcing at the main contacts of the switch is substantially eliminated and such that a positive wiping action at both the main and auxiliary contacts is insured.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

l igure 1. is a front elevation of an electric switch embodying my invention, the switch being shown in circuit closed position; Fig. 2 is a side elevation, with parts broken, away. of the embodiment of my invention shown in Fig. 1, the switch being shown in circuit closed position; F 3 is a view similar to Fig. 2 with the switch shown tripped to circuit open position Fig. .4. is a side view partly in elevation and partly in section with parts broken away illustrating the operating mechanism of the switch shown in Fig. 1 in circuit closed position, and Fig. 5 is a view similar to Fig. 3 illustrating the parts of the switch in dit- "iterent positions during switch closing op eration.

In the several figures of the accompanying drawing, I have illustrated an electric switch embodying my invention in the form of a circuit breaker comprising suitable cireuit controlling means, such as a movable member 1 which may be a substantially rigid member and which is adapted to carry electric current and arranged to be operated to control primary and secondary contacts 2 and. 3, respectively. and to be controlled when in circuit closed positionv by any suitable electroresponsive tripping means such as an elcctro-magnet 4 having a movable armature or plunger arranged to actuate a tripping member 5. For the purpose of supporting the various parts of the circuit breaker, any suitable means such as a base 6 of insulating material may be used. The primary contact 2 is associated with a main terminal or stud 7 secured to the base 6 and the circuit controlling member 1 is connected intermediate the ends thereof by any suitable electric current conducting means,

such as a flexible conductor or 'pig tail 8, to another main terminal stud 9. The secondary contact 3, which may be a carbon contact is associated with an auxiliary ter minal or stud 10 secured to the base 6 and connected by any suitable electric current conducting means, such as a lead 11, to the main terminal 7. The secondary contact 3 is consequently in a circuit across the terminals 7 and 9, that is to say in shunt with the circuit controlled by the circuit breaker. One end 2 of the circuit controlling member 1. is arranged to engage the contact 2, and

the other end is provided with a carbon contact 3 arranged to engage the contact 3.

In order that the circuit controlling membcr may be movable, it may be mounted on a support or block 12 secured over intervening insulation 13 to a rodor shaft 14 by any suitable means such as a clamping member 15. The shaft 1st is rotatably mounted in suitable supports or brackets 16 and 17 secured to the base 6 and may be of rectangular cross-section as shown, one end being rounded for hearing in the bracket 16. The bracket 17 may comprise a bifurcated portion including arms 18 and the other end of the shaft 1 1 may be square and set in suitable bushings 19 journaled in the arms 18. The bushings 19 may be provided with collars and be securcdtothe shaft 14 to prevent endwise movement thereot. For biasing the circuit controlling member 1 to circuit open position, suitable biasing means such as a spring 20 secured to the bracket 16 and to any other suitable point with respect to the shaft 14 such as the end of a crank or pin 21 secured thereto may be provided. The bracket 17 may, for compactness and simplicity of structure, alsobe constructed and arranged to form apart of the magnetic circuit of the electromagnet 4. For this purpose the bracket 17 may be made of magnetic material or comprise a portion of magnetic material, for example the rear or part adjacent the base 6, in the form of a yoke in which the energizing winding of the electromagnet 4 is mounted, the lower portion of the yoke being split as at 17 to permit of clamping the plunger guide sleeve therein. lhe eleclromagnet a has a pole piece 2 secured in a hole in the bracket 17 and the triooine" member actuated by the 1 L r x plunger or the cicctromagnet 4- moves through a, hole in the pole piece 23. Unitable m ans for preventing damage to the electromagnet l by arcs formed upon the opening of contacts 3'. such as an arc barrier 2% is provided.

In order to provide for the opening and closing of" the primary and secondary contacts 2, 2 and 3. 3 respectively in the proper sequence and also to provide a wiping action of the contacts, the circuit controlling; memher 1 is mounted for movement relative y to the block 12 and therefore to the shat 1i; since the block 12 is rigidly secured to the shaft 1%. For this mov nient. the block 12 may be provided with suitable xtensions such as bolts and 2b "hich the circuit controlling member is slidably mounted and suitable biasing means such as springs 2'? and 28 which may be mounted on opposite sides of the circui controlling member 1 on the bolts 25 and respectively. are provided for biasing; one end ot the circuit controlling member 1 away From and the other end towards the 1-? l2. he bolts 25 and 26 thus serve to carry the cii cuit con trolling member 1 and to permit movement thereof relatively to the blocl 12. Move controlling ilo ment of one end 01"? the circm member 1 away from the l lock 12 und action of the spring" 27 is limited by a stop such as the head or the bolt the spring; 27 being between the member 1 and the block 12. while movement or" the other end toward the block 12 under the action of spring 28 is limited by the block 12. the spring); 28 being; between the member 1 and a stop such as the head of the bolt 96. Qince the springs 27 and 28 are on opposite sides of the contact controllin; member 1 and are both under compression in the circuit closed position or this member. they tend to turn the member 1 ountei -lockwise or in a direction opposite to the direction in which the shaft 14 is biased. to turn by the spring 20. spring 28 holding memb-r 1 or contact 3- against contact 3 and springs 27 and 2S tending to turn block 12 clockwise. Consequently. the springs 27 and 2S assist the spring: 90 in moving the circuit controllingm rober 1 to circuit open position at contact 2 since the forces exerted by the springs 27 and QR on the circuit controlling; member 1 are directed towards the contacts 2 and 3 respectively and therefore tend to cause the block 12 to turn clockwise.

For actuating the circuit controlling member 1. there may we mounted on the shaft 14 suitable means such as a crank 29 which for simplicity in construction is preferably mounted on the square end of the shaft 1 1 r the between the arms o l the bracket 17 'l'hc bushings 19 are preferably made long enough to have their inner ends abut the sides o l the rank so as to hold the sane: on the shaft 1% in a definite position which may be suliistantially midway of the bracket arms 18. For limiting; the movement (it the circuit controlling member 1, in circuit openin; direction, suitable means may be provided such a a stop or pin 30 ext-ending between the bracket arms 18 in thepath of movement of the crank 29. The shaft lland the crank 29 therefore comprise means adapted to be operated to actuate the circuit controlling member 1.

For operating the actuating means. 1 provide an operating mechanism which may comprise an operating member or lei'cr having a plurality of arms 31. and which may be pivotally mounted at an intermediate point thereof on the bracket 17 between the arms 18 thereof. The lever arm 32 may be provided with a handle Eli: oil insulating material and is preferably made longer than the lever arm to obtain the mechanical ad *antage thereby atiordcd. Movement of the operating member is limited in both directions by a stop such as a pin extending between the liu'aclzet arms 18 in the path of movement in one direction of lever arm and in the path of movement in the opposite direction of lever arm 31.

For establishing a trip tree operatinp connection with the switch actuating means. I provide pivotallv associaten at 36 with the lever arm 31 of the operating member. a latching member 37 which may comprise a bifurcated portion arranged to straddle the crank 29 and carrying a :atch such as a roller 38 arranged to engage a notch or shoulder in the upper portion of the crank and a relatively heavy tail portion ll) exidin l. when the switch is closed. in the lh oi movement of the tripping member 5 the clcctroresponsive device 1. see Fiji. 1. The latching menmer 37 therefore performs a double function. in that it. acts as a latch and also as one of the links of a toggle comprising itself and lever arm 31 ot the opera; 1 member. This toggle may be arra iged to be overset in the circuit closed position of the switch. the toggle bein r restrained trom collapsing; by the stop against which the lever arm 32 abuts. see Fig. 4. Vith this construction and arrangement of parts. it is obvious that the switch is automatic or trip tree from the handle since there is no fixed or permanent connection between the toggle and the switch actuating means. that is to say between the latching member 37 and the c 'ank 29. In other words the latching member 37 being releasable from the crank 29 independendly of the operating member, the switch cannot wit-WW be held closed on an abnormal circuit condition event-hough the lever 32 or handle 3:1 has a downward force exerted thereon.

Although I have shown only a single pole circuit breaker, that is to say only one circuit controlling member 1, itis obvious that my invention is applicable to a construction embodying a double pole circuit breaker, that is to say a circuit breaker embodying two circuit controlling members 1, one in each side of the circuit to be controlled. For this construction, it is merely necessary to increase the length of the shaft 14. and mount thereon between the brackets 16 and 17 another circuit controlling member in the same manner as the one shown.

For the'operation of an electric switch constructed in accordance with my invention, it will be assumed that the parts are in the circuit closed position as shownin Figs. 1, 2 and 4. In'this position, the catch 38 of the latching member 37 is in engagement with the notch or shoulder of the crank 29 and the toggle comprising the latching member 37 and the lever arm 31 of the operating member is overset and restrained by the stop 35 against which the lever arm 32 of the operating member abuts. The circuit controlling member 1 is there fore held in circuit closed position at the primary and secondary contacts 2, 2 and 3, 3, respectively, against the bias of the springs 20, 27 and 28, the circuit controlling member 1 being against the springs 27 and 28 which are in compression, see Fig. 2. If now the electromagnet 4 is energized a predetermined amount, either in response to an abnormal circuit condition or otherwise, the plunger thereof will be attracted and the trippingmember 5 raisedto strike the tail portion 39 ofthe latching member 37 a sharp blow which releases the catch 33 ot the latching member 37 from the notch in the crank 29, and the shaft 14 under the bias of springs 20, 27 and 28 is caused to turn in a direction to carry the circuit controlling member 1 to circuit open position as shown in Fig. 3. The latching member 37 is shown in Fig. 3 with its center of gravity over its pivotal center 36 and at rest against the operating member as this is the position it usually assumes when tripped. This is, however, immaterial as far as my invention is concerned as the latching member 37 may not always be struck hard enough by the tripping member 5 to throw it over its pivotal center. In this case, it will fall back towards the crank 29 with the catch 38 resting on the rear or cam-shaped portion of the crank 29. The c 'ank 29 comes to rest against the stop 30 in the full open position of the switch. It will be noted that there is substantially no movement of the operating member as the lever arm 32 thereof remains against the stop 35 and is inherently biased against this stop by the weight of the overhanging lever arm 32 and the handle 34;. During the circuit opening movement, the circuit controlling member 1 under the action of springs 27 and 23 is caused to move relatively to the block 12 and in the opposite direction thereto, and the circuit is first interrupted at the primary contact and subsequently at the secondary contact 3. he spring 27 holds the circuit. controlling member 1 against contact 2 and the spring 28 holds it against the secondary contact l Vhen the shaft 14 has turned sufiiciently tor the circuit con trolling member 1 to abut the head of the bolt 25, further movement of the shaft 1 1 interrupts the circuit at 2. 2', but the spring 28 still continues to bias the circuit controlling member 1 with bolt as a fulcrum, that is to say to hold contact 3 against contact 3. In this way the circuit controlling member 1 is caused to move relatively to the block 12 and contact 3 to roll or slide over contact 3 until the circuit controlling member 1 abuts the lower edge of the block 12. Movement of the circuit controlling member relatively to the shaft 14 then ceases and further movement of the shaft 14 under the bias of spring 20 separates the arcing contacts 3, 3'.

It is, of course, obvious that the switch may be opened independently of any elec troresponsive means by giving the lever arm 32 or handle 34 a sharp blow upwards smficient to move the toggle 31, 37 to an underset or unstable position. Also the plunger of the electromagnet 4 may be provided with an extension button to be operated manually as is well known to the art, for manually releasing the latching member 37. I

To close the switch, the latching member 37 must first be reset in latching position in order to reestablish the toggle connection between the operating mechanism and the actuating means. In order to accomplish this, the operating member is turned counter-clockwise referring to Figs. 3 and 5, that is to say the lever 32 is turned upwardly from the position shown in Fig. 3 to the position shown in full lines in Fig. 5. The latching member 37 is thereby caused to turn over its pivotal center whereupon it falls toward the crank 29, the catch. dropping into the notch in a position to engage the shoulder thereof upon clockwise movement of the operating member. If the latching member is not raised to the position shown in Fig. 3 when tripped, the catch 38 will rest on the rear or cam shaped portion of'the crank 29 and upward movement of the lever arm 32 will draw the catch 38 outward over the cam shaped surface of the crank 29 until the catch "falls into the notched portion thereof. The operating member is now turned clockwise with reference to Fig. 5 or lever arm 32 downwards. This causes the catch to engage the shouldered or notched portion of the crank 29 as shown in the full line position Fig. 5. As the operating memb r is turned clockwise, the contact 3 abuts the contact 3, see Fig. 4 dotted line position. Further movement of the operating member causes movement of the circuit controlling member relatively to the shaft 14; for, inasmuch as the contact 3 is against the contact 3, the circuit controlling member is first caused to move away from the lower edge of block 1:2 thereby placing the spring 28 in compression. At the same time, the angular movement of the bolts 25 and 26 causes the circuit controlling member to move downward and the con tact 3 to roll or slide over the contact 3. hen the circuit controlling member strikes contact 2, the upper end of the member is moved towards block 12 putting the spring 27 in compression. The remainder of the movement of the operating member compresses both springs 21' and 28 and sets the toggle 31, 37. Due to the continued angular movement of the bolts 25 and 26 the upper end 2 of the circuit controlling member is caused to slide down over contact 2 with a wiping action as also does contact 3 on contact 3. The primary and secondary contacts 2 and 3 respectively are therefore opened and closed in the proper sequence to substantially eliminate arcing at the primary contacts and the wiping action at the contacts ensures the best condition for a low resistance contact.

Although I have shown and described my invention in considerable detail, I do not wish to be limited to the specific details thereof, as shown and described, but may use such modifications, substitutions, or equivalents thereof. as are embraced within the spirit of my invention.

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

1. In an electric switch. actuating means biased for movement in circuit opening direction, a circuit controlling member mounted on said actuating means and biased for movement relatively thereto in a direction opposite to the movement of said actuating means, and a plurality of contacts arranged on opposite sides of said circuit controlling member adjacent the ends thereof and adapted to be engaged thereby, the construc tion and arrangement of parts being such that upon movement of said actuating means in circuit closing direction said circuit controlling member is caused to engage one of said contacts with a wiping action and then to move relatively to said actuating means in a direction opposite to the direction of movement of said actuating means and subsequently to engage another of said contacts with a wiping action.

2. An electric switch comprising actuating means biased to circuit opening position, a circuit controlling member mounted there on for movement relatively thereto, one end. of said member being biased towards and the other end away from said actuating means, and primary and secondary cont-acts arranged adjacent the ends of said member and adapted to he engaged thereby, said secondary contact being arranged adjacent the end of said member biased towards said actuating means and on the same side of the member as the actuating means. and said primary contact being arranged adjacent the other end of said member and on the other side thereof, the construction and arrangement of parts being such that upon movement of said member to circuit open position said secondary contact is disengaged subsequently to said primary contact and upon movement of said member to circuit closed position each of said contacts is engaged thereby with a wiping action, the engagement of the primary contact being subsequent to the engagement of the secondary contact.

3. An electric switch comprising actuating means biased to circuit opening position, a circuit controlling member mounted thereon for movement relatively thereto, one end of said member being biased towards and the other end away from said actuating means, and a plurality of contacts arranged on opposite sides of said member adjacent the ends thereof and adapted to be engaged thereby, the contact adjacent the end of the member biased towards the actuating means being situated on the same side of the member as the actuating means and the contact adjacent the other end of said member being situated on the opposite side thereof. the construction and arrangement of parts being such that upon movement of said member to circuit open position said first contact is disengaged subsequently to said second contact.

4. An electric switch comprising a shaft biased to turn in one direction, means for turning the shaft in the opposite direction, supporting means mounted on said shaft, a substantially rigid circuit controlling member slidably mounted on said supporting means and biased for movement thereon relatively to said shaft, and a plurality of substantially fixed contacts arranged on opposite sides of said circuit controlling member adjacent the ends thereof, the construction and arrangement of parts being such that upon movement of said shaft in a direction opposite that in which it is biased said member engages one of said contacts subsequently to the other thereof whereby the member is caused to move against the bias thereof rela tively to said. shaft and in a direction opposite the movement thereof and to engage said contacts With a wiping action and such that upon movement of said shaft in the direction in which it is biased the member disengages said contacts in the reverse order to which they are engaged whereby the member is caused by its bias to move relatively to said shaft in a direction opposite the movement thereof.

5. In an electric switch of the class de* scribed, the combination with a pivoted supporting member, a conducting switch member mounted on said supporting member, stationary contacts located near the ends of said con ductingmember and on opposite sides thereof whereby upon rotation of said supporting member said conducting member engages said stationary contacts, and means for yieldingly supporting said conducting memher on said supportin member comprising a pair of springs, one floated on each side of the. pivot about which said supporting member turns arranged to bias said conducting member toward the adjacent contact mem- 26 bars.

6. In an electric switch of the class de scribed, a pivotally mounted contact supporting block, a conducting member carried by said block and movable relatively thereto, fixed contact members located on opposite sides of said conducting member adjacent the ends thereof, spring means for biasing one end of said conducting member away from said block and the other end of said conducting member'toward said block, said fixed contact members being so located with respect to the ends of'said conducting member that upon pivotal movement of said block the end of said conducting member biased toward said block engages the adjacent fixed contact before the other end of said conducting member engages the other fixed contact, whereby upon turther pivotal movement of said block said spring means permits said conducting member yieldingly to engage said contacts.

In witness whereof I have hereunto set my hand this 24 day of August, 1922.

WILLIAM L. KUBACH.

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