US1725106A

US1725106A - Electric switch

Info

Publication number: US1725106A
Application number: US141722A
Authority: US
Inventors: William M Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 1926-10-15
Filing date: 1926-10-15
Publication date: 1929-08-20
Anticipated expiration: 1946-08-20

Description

Aug. 20, 1929. w, SCOTT 1,725,106

ELECTRIC SWITCH Filed Oct. 15, 1926 4 Sheets-Sheet 1 Will/am MScoff A TTORNEY I Aug. 20, 1929. w. M. SCOTT I ELECTRIC SWITCH Filed Oct. 15, 1926. 4 Sheets-Sheet FIG 2 INVENTOR I/Wl/iamM Scoff B ATTORNEY Aug. 20, 1929. w. M. SCOTT ELECTRIC SWITCH Filed Oct. 15, 1.926 4 Sheets-Sheet 3 58 FIG. 3

H n w INVEN TOR VVi/Ifam MScoff A TTORNEY Aug.20, 1929. I WMS OTT 1,725,106

ELECTRIC SWITCH Filed Oct. 15, 1926 4 Sheets-Sheet 4 INVENTOR \M/liam MSco/f Y AMA @142 .v A TTORNE UNITED STATES PATENT OFFICE.

WILLIAM M. SCOTT, OF TREDYFFRIN TOWNSHIP, CHESTER COUNTY, PENNSYLVANIA.

ELECTRIC SXVITCH.

Application filed October 15, 1926.

My invention relates to electric switches or circuit breakers.

In accordance with my invention, in response to partial or complete de-energization of an elect-ro-magnct, as, for example, an underload or non-voltage magnet, any suitable switch tripping mechanism is actuated by the electro-magnet armature as it moves from normal to abnormal position under the mflu ence of suitable biasing mechanism, as a helical spring, the armature thereafter returning to normal posit-ion prior to operation of the tripping mechanism to reset the switch in circuit-closing position.

Further in accordance with my invention, the aforesaid electric switch or circuit breaker comprises a movable contact member and a winding or electro-magnet connected across the circuit to be controlled, the armature of the electro-magnet being biased to coacting position with respect to its winding for controlling departure of the movable contact member from circuitclosing position, and for controlling the aforesaid electro-magnet there is utilized a switch connected across the circuit to be controlled, which switch, with the circuit breaker in open or abnormal position, is closed prior to the application of a force to the armature tending to move the same from normal position with respect to its winding.

My invention resides in the features and details of construction of the character heroinafter described and claimed.

For an illustration of one of the forms my invention may take, reference is to be had to the accompanying drawings in which:

Fig. 1 is a side elevational View of an electric switch constructed in accordance with my invention and shown in circuitclosing position.

Fig. 2 is a front clevational view of the structure shown in F ig. 1.

Fig. 3 is an enlarged plan view of the electro-magnet armature and the mechanism associated therewith.

Fig. 41 is a side elevational view of the structure shown in Fig. 3.

Fig. 5 is side elevational view of the structure shown in Fig. 4 butwith the parts in another position.

, Fig. 6 is an end elevational View of the latch. tripper.

Serial No. 141,722.

Fig. 7 is a schematic View illustrating one form of circuit connection which may be utilized with the circuit breaker described herein.

Referring to the drawings, a base 1 of slate, marble, or other suitable insulating material, has secured thereon the main terminal blocks 2 and 3 with which electrical communication is afforded through the heavy current conducting studs 4. Adapted to bridge and electrically connect the terminal blocks 2 and 3, and thus close the circuit, is the movable contact member 5 which is preferably a laminated bridging member and as such, particularly when very heavy currents are carried thereby, is a stiff spring which is more or less compressed when in the circuit closing position shown in Fig. 1.. member 5 is secured upon the arm 6 pivoted to the housing 7 at S. The intermediate metallic shunt contact 9 and the movable shunt carbon contact 10 are also carried by the pivoted arm 6, and engage respectively the stationary metallic shunt contact 11 and the stationary shunt carbon contact- 12. Vhen the member 5 separates from the

main terminal blocks

2 and 3, the current is shunted through these shunt contacts which open in succession, the final are taking place between the

carbon contacts

10 and 12.

The operators lever 13 having a hand grip 14 is pivoted at 15 to the housing 7. Pivoted to the inner end of the operators lever 13 at 16 is a link 17, to whose other end there is pivoted at 18 a pair of spaced links 19. To the other end of links 19, at 20, is pivoted the arm 6. Pivoted at 18, independently of the

links

17 and 19, are the links or levers 21 pivoted at their inner ends at 22 to the housing 7. The link 17, which may be considered as bifurcated or having two side arms, is provided with a surface 17A adapted to engage the surface 13A on the operators lever 13 as shown in Fig. 1., the engagement of these surfaces preventing the over travel of the toggle comprising the links 13 and 17, the end pivots being 15 and 18. and the intermediate pivot is 167 Upon the lever 13 is provided a buffer 23 adapted to be engaged bv the link 19 to cushion the same and attached parts when the circuit breaker reaches full open circuit position. 1' second toggle iscomj'irised of the li'iilt' 21 and 19, the end ji i 't ts being 22 The movable contact and 20, and the intermediate pivot is 18. As shown in Fig. 1, the pivot 20 does not reach the imaginary straight line joining the centers of the pivots 22 and 18 but approaches so close thereto that a toggle action occurs.

Qne or more springs S is or are connected at one end to the pivoted arm 6 and at its other end to the pivot 16 forming ajomt between the toggle links 13 and 17. lVith the parts in the position shown in Fig. 1 the spring S is under tension. When the parts are in open circuit position,=the switchor circuit breaker may be closed by grasping the handle 14 and rotating. the operators lever 13 in a clockwise direction about the pivot 15. In so doing, the closing force is transmitted from the link-13 through the link 17 to the pivot 18 which rotates the pair of levers or links 21 in a counter-clockwise direction about pivot 22. This rotation of links 21 is accompanied by a transmission of force from the said links through the links 19 to the pivot 20 causing a counter-clockwise rotation of the arm 6 about its pivot 8, thus bringing the bridging member 5 closer and closer to the ter

minal blocks

2 and 3. VJ hen the stiif spring contact 57 engages the

main contacts

2 and 3, it strongly opposes further movement. due to its spring characteristics. When this first contact position is reached, the toggles are almost in the position shown in Fig. 1, that is, both toggles are nearly straightened out so'that they are exerting nearly their maximum force in directions determined'by im aginary straight lines joining theirend pivotsr That is to say, the toggle 13, 17 is exerting almost its maximum force upwardly on the pivot18, as viewed in Fig. 1'; and the toggle 19, 21is exerting almost its maximum force toward the left on pivot 20 and, therefore, upon the contact member 5. A further movement of the operators lever 13 is, as before stated, resisted by the spring of the member 5. But the toggles arenow in the position where they are capable of exerting their practically great est thrusts and, in consequence, an operator is enabled by the further movement of the lever 13 to bring the contact member 5 firmly and securelyinto engagement with the

terminal blocks

2 and 3 by slightly deflecting and bending the still spring 5. The parts have now attained the position shown in Fig. 1 and 'are'restrained or latched in that position by the dog or latch member 24 pivoted loosely on the pivot 16 and thrusting at its lower left hand end 25, Fig. 1, against the roller 26, pivoted to the housing on pin 27. The latch 24 is thus under compression and prevents the collapse of the toggles and the opening of the switch or circuit breaker.

Mounted on the basal adjacent one side of the mechanism described above, Fig. 2, is a winding'28 having a core 29 disposed therewithin. Coacting with winding 28 and core 29 are the pole pieces 30 having pole tips 30*. Extending upwardly from .each side of the left hand pole piece 30, as viewed in Figs. 1, 4 and 5, is a plate 31, Fig. 2, said plates receiving a pin or member 32 on which is pivoted the armature 33 from which rises, adjacent its free end, the projection 34 to which is secured one end of a helical spring 35 or the like, whose other end is suitably secured to a stop member 36 whose legs 37 are pivoted on the pin 32. Movable with and preferably formed integrally with

member

36, 37 is an arm 38 in whose lateral extremity 39 is secured a pin 40 adapted to extend through a slot 41 in a link 42. In the other end of link 42 is mounted a pin 43 which extends through a spacing collar 44 and is connected to a member 45 mounted on and movable with link 21.

Pivoted to the pin 27 are the lugs 46 of a dog or latch tripper 46, Fig. 2, herein shown as comprising a lateral arm or member 47 and a tripping member 48. As illus trated in Fig. 2, arm 47 is disposed in part in the path of movement of armature 33 while member 48 normally is in position to engage the latch 24. Pivoted at 49 on the arms 50 extending laterally from base 1 is a conductive member or link 51 whose end removed from pivot 49 is provided with a slot 52 through which passes the reduced end 53 of a rod 53 mounted on and movable with the member 54 secured to the movable contact member 5 and formed of suitable insulating material. Secured to and extending laterally from the base 1- are the

members

55 and 56 formed at their ends with contact members 57 spaced apart a distance corresponding with the width of link 51. In the example shown, the

members

55 and 56 are formed-of suitable conductive material and are directly in electrical communication with their respective contact members 57.

Apparatus of the character herein described is especially adapted for use as a nowoltage control device. As one example of a system with which the herein described apparatusmay be associated, there is indicated in Fig. 7 the line conductors L and L traversed by current from any suitable source, not shown. Connected in se ries with the terminal blocks 2, 3 and across the line L, L is any suitable load herein shown as a motor M. Likewise connected across the line is the coil 28, the contact members 57 being included in this circuit.

The operation is as follows:

During continuance of a voltage across the line of sufiicient magnitude to maintain coil 28 at'a degree of energization holding armature 33 in contact [with the pole tips 30 against the retractive force of spring 35, the parts remain in circuit closing position, as shown in F ig. 1; that is, with the contact member 5 closed upon the terminal blocks 2 and 3.

However, should the voltage across the line drop sufficiently, spring 35 overbalances the magnetic attraction of coil 28 and withdraws armature 33 from pole tips 30*, the armature at its free end engaging lateral arm 47 on latch tripper 46 to rotatethe same in counterclockwise direction, Fig. 1, whereby trip member 48 slightly moves the dog or latch member 24 in a clockwise direction, Fig. 1. This allows the bridge 5 and springs S to collapse the toggles and the circuit breaker parts fly to open circuit position. \Vhile moving to open circuit position, link 42 moves downwardly, Fig. 1, and arm 38 and stop member 36 move in a clockwise direction about point 32, Figs. 1 and 4, whereby the tension of spring 35 is relaxed and, as the circuit breaker parts reach open position, the armature 33 under the influence of gravity moves to normal position upon its pole tips 30, Fig. 5.

\Vhen the parts moved to abnormal or open circuit position as aforesaid, link 51 was rotated in a clockwise direction, Fig. 1, and withdrawn from between the contact members 57, thereby opening the circuit through the coil 28.

With the parts thus in open circuit position, lever 13 may be actuated and, as contact member 5 closely approaches the terminal blocks 2 and 3, the conductive link 51 passes into engagement with contact members 57, thereby closing the circuit through coil 28. Closure of the circuit through coil 28 is thus effected as link 42 is moving upwardly, Figs. 1 and 4. However, due to the lost motion arrangement comprising the pin 40 and slot 41, upward movement of arm 38 does not'occur until after the circuitthrough coil 28 has been closed as stated above. After the circuit through said coil 28 is closed, arm 38 is moved upwardly and stop member 36 is rotated in a counterclockwise direction, Fig. 1 and 4, until link 42 reaches the upward limit of its travel at which time the end of stop member 36 engages base 1. Inthis manner, spring 35 is placed under tension, subsequent, however, to energization of coil 28. Accordingly, if the voltage across the line is of sullicient magnitude to overbalance the retractive force of spring 35, the circuit breaker will remain in circuit closing position. If such is not the case, spring 35 will immediately move armature 33 upwardly to trip the breaker.

\Vhat I claim is:

1. The combination with an electric switch comprising a movable contact member and means for restraining said member in normal position, of an electro-magnet and its armature, means biasing said armature from normal position with respect toits electro-magnet for releasing said rest-raining means to move said contact member to abnormal position, and means for disabling said biasing means by the time said contact member has reached abnormal position.

2. The combination with an electric switch comprising a movable contact member and means for restraining said member in normal position, of an electro-magnet and its armature, means biasing said armature from normal position with respect to its electro-magnet for releasing said restraining means to move'said contact member to abnormal position, and means for disabling said biasing means while said contact member is moving toward abnormal position.

3. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit closing position, means responsive to an abnormal circut condition controlling departure of said member from circuit closing position comprising an electro-magnet having'an armature biased toward normal position with respect to its elcctro-magnet, means for moving said armature from normal position with respect to its electro-magnet, and means for disabling said last-named means before initiation of movement of said contact toward normal position. a

4. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit closing position, means responsive to an abnormal circuit condition controlling departure of said member from circuit closing position comprising an electro-magnet having an armature biased under the influence of gravity toward normal position with respect to its electro-magnet, means for moving said armature from normal position with respect to its electro-magnet, and means for disabling said last-named means before initiation of movemcnt of said contact toward normal position.

5. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for re straining said member in circuitclosing position, means responsive to an abnormal circuit conditon controlling departure of said member from circuit closing position comprising an electro-magnet having an armature biased toward normal position wit-h respect to its electro-magnet, a spring for moving said armature from normal position with respect to its electro-magnet, and means for disabling said spring by the time said contact member has reached abnormal position.

6. The combination with an electric switch comprising a movable contact member and a circuit controlled there-by, of means for restraining said member in circuit closing position, means responsive to occurrence of predetermined drop in voltage across said circuit controlling departure of said member from circuit closing position comprising a winding connected across said circuit and having an armature biased toward normal position with respect to its winding, means for moving said armature from normal position with respect to its winding, and means for disabling said last-named means before initiation of movement of said contact toward normal position.

7. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit closing position, means responsive to occurrence of pre-' determined drop in voltage across said circuit, controlling departure of said member from circuit closing position comprising a winding having an armature biased under the influence of gravity toward normal position with respect to its electro-magnet, means for moving said armature from normal position withrespect to its winding, and means for disabling said-last-named means while said member is moving toward abnormal position.

8. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit closing position, means responsive to an abnormal circuit condition for moving said member to abnormal position comprising an electromagnet having an armature biased toward normal position with respect to its electromagnet, a'second switch controlling the circuit of said electro-magnet, and means for opening said switch and disabling said lastnamed means during movement of said contact toward abnormal position.

- 9. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit closing'position, electro-magnetic means responsive to an abnormal circuit condition comprising an armature controlling departure of said member from circuit closing position, means for moving said armature from normal position with respect to its electro-magnet upon occurrence of said abnormal condition, and means controlled by said restraining means for disabling said last-named means during movement of said contact member from normal position.

10. In an electric switch, a movable contact member, means for restraining the same in normal position, a movable member for actuating said restraining means, an electro-magnet, an armature for actuating said movable member biased into co-acting relation with respect to said electro-magnet, a spring biasing said armature in reverse direction, and means actuated through the agency of said contact membeer for decreasing the tension of said spring during movement ofcontact member from normal position.

11. Thecombination with an electric switch comprising amovable contact member and means for restraining said contact member in normal position, of an electro-magnet having an armature normally biased into engagement therewith, a member movable in response to movement of said switch to abnormal position, a spring secured to said second-named member and'armature, and means'co-acting with said armature for effecting movement of said switch to abnormal position.

12. The combination with an electric switch comprising a movable contact member and means for restraining said contact member in normal position, of an electro-magnet having a pivoted armature normally biased into engagement therewith, a pivoted member movable in response to movement of said switch 'to abnormal position, a spring connected at its ends to the free ends of said second-named member and armature, and means co-actingwith said armature for efi ecting movement of said switch to abnormal position.

. 13. In. an electric switch, a movablecontact member, means for restraining the same in normal position, a movable member for actuating said restraining means, an electromagnet, a second switchactuated by said restraining means for controlling said electromagnet, an armature for actuating said movable member biased into (Io-acting relation with respect to said electro-magnet, a spring biasing said armature in reverse direction, and means comprising a lost motion device connected to said restraining means and controlled thereby for changing the tension of said spring during movement of said contact member. p

, 14. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit-closing position, means for releasing said 'restraining means upon occurrence of an abnormal condition in'said circuit comprising an electro-magnet and an armature normallyrbiased toward said magnet, resilient means urging said armature in opposite direction and controlled by the position of said contact member, a second switch cooperating with said contact member for controlling the circuit of said electro-magnet, said second switch being moved to closed position during closing movement of said contact member, and means disabling said resilient means until said second switch has reached its closed position.

15. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of means for restraining said member in circuit-closing position, means responsive to abnor mal circuit condition for moving said member to abnormal position comprising an electro-magnet having an armature biased toward normal position with respect to its electro-magnet, a second switch controlling the circuit of said electro-magnet, means for opening said switch and disabling said lastnamed means during movement of said contact toward abnormal position, and lost-motion means for permitting closure of said switch prior to energization of said means for biasing the armature to abnormal position.

16. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of restraining means for maintaining said contact member in normal position, electro-magnetic means for releasing said restraining means comprising an armature normally attracted towards its magnet, resilient means acting on said armature and opposing the normal attraction of said magnet when said contact member is in normal position, and means for maintaining said resilient opposing means ineffective from the time said contact member is moving towards abnormal position until the same is in close proximity to its normal position.

17. The combination with an electric switch comprising a movable contact member and a circuit controlled thereby, of restraining means for maintaining said contact member in normal position, means for releasing said restraining means upon occurrence of an abnormal condition in said circuit comprising an electro-magnet and an armature normally attracted thereto, means normally urging said armature in opposite direction, a second switch operated by said contact member for controlling the circuit of said electro-magnet, and means for rendering said last-named means ineffective while said second switch is in open position.

WILLIAM M. SCOTT.