US3072763A

US3072763A - Spring actuated contact opening and closing mechanism

Info

Publication number: US3072763A
Application number: US8856A
Authority: US
Inventors: Jr Edwin C Goodwin
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1960-02-15
Filing date: 1960-02-15
Publication date: 1963-01-08
Anticipated expiration: 1980-01-08

Description

4 Sheets-Sheet 1 E. C. GOODWIN, JR

SPRING ACTUATED CONTACT OPENING AND CLOSING MECHANISM Jan. s, 1963 l Filed Feb. l5, 1960 Jan. 8, 1963 E' C' GOODW'N JR 3,072,763

SPRING ACTUATED CONTACT OPENING AND CLOSING MECHANISM Filed Feb. l5, 1960 4 Sheets-Sheet 2 JM/umbri dw/IM Q. Spad/MMM JA.

:7l/M FA' @www Jan. 8, 1963 E' C- GOODWIN JR 3,072,763

SPRING ACTUATED CONTACT OPENING AND CLOSING MECHANISM Filed Feb. l5, 1960 4 Sheets-Sheet 5 Jan. 8, 1963 E. c. GOODWIN, JR

SPRING ACTUATED CONTACT OPENING AND CLOSING MECHANISM Filed Feb. 15, 1960 4 Sheets-Sheet 4 United States Patent Oilce ,3,072,763 Patented Jan. 8, 1963 3,072,763 SPRING ACTUATED CONTACT PENING AND CLOSNG MECHANISM Edwin C. Goodwin, Jr., Canton, Mass., assigner to Allis- Chalmers Manufacturing Company, Milwaukee, Wis. Filed Feb. 15, 1960, Ser. No. 8,356 7 Claims. (Cl. 200-92) This invention relates to a circuit breaker structure and more particularly to a new and improved mechanism for opening and closing its contacts.

Heretofore circuit breakers of the type disclosed have been electrically closed by means of `solenoids or high torque motors which require a supply of electrical energy throughout'the closing cycle. A failure of the electrical energy source results in the circuit breaker failing to start to close or failing to complete the closing stroke after it had been initiated, depending on the time of failure. In failing to close the arcing contacts the circuit breaker cannot be placed in service and the continuity of the electrical system it protectsl cannot be restored. By failing to complete a closing contact operation the circuit breaker not only cannot restore the circuit it protects but in addition severe damage to the circuit breaker may occur by a partial closing operation.

In accordance with the invention claimed a new and improved circuit breaker structure is provided whose actuating mechanism is independent of a sustained electrical source during a Contact closing operation and can store energy for long periods of time. When this stored energy is released it closes the contacts quickly and positively. This mechanism comprises a load means for closing a pair of contacts upon bias thereof, a load means for opening the contacts upon bias thereof and a triggering means for the opening means to separate the contacts. The closing Contact means is connected to the opening means for biasing the opening means upon closure of the contacts.

It is, therefore, one object of this invention to provide a new and improved contact controlling mechanism for a circuit breaker structure.

Another object of this invention is to provide a new y and improved contact controlling mechanism for circuit breakers which is not dependent on sustained electrical energy.

A further object of this invention is to provide a new andimproved contact controlling mechanism which can store energy for closing and opening a pair of cooperating arcing contacts for long periods of time by means of charged springs.

A still further object of this invention is to provide a new and improved circuit breaker Contact controlling mechanism which is simple, dependable and easily maintained.

Objects and advantages other than those set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

FIG. l is a vertical cross sectional View partly in elevation of a circuit breaker structure taken along the line I--I of FIG. 2 utilizing a transmission mechanism employing the present invention and showing the contact closing and opening springs in their biased and unbiased positions, respectively;

FIG. 2 is a partial front elevational view of the circuit breaker structure shown in FIG. l;

FIG. 3 is an enlarged partial View of the circuit breaker racking and arcing contact controlling mechanism shown in FIG. 2 in the arcing contact controlling position;

FIG. 4 is an enlarged partial View similar to FIG. 3 showing the circuit breaker and arcing contact controlling mechanism in the racking position;

FIG. S is a View similar to FIG. l showing the circuit breaker contacts in closed position and the contact closd ing and opening springs in their unbiased and biased positions, respectively; and

FIG. 6 is a diagrammatical view similar to FIG. 5 showing the contact controlling mechanism in the trip free position.

Referring more particularly to the drawing by characters of reference FIGS. l-S illustrate a circuit breaker 10 utilizing an integrated transmission mechanism 11 for selectively actuating a circuit breaker racking mechanism 12 and an arcing contact controlling mechanism 13. The transmission mechanism 11 comprises a pinion-or driving shaft 14 having iixedly mounted thereon a iirst gear or sprocket 15 and a second gear or pinion 16. Shaft 14 is rotated by means of a suitable electric motor 17 or by means of a manually rotatable handle 18. Rotation of handle 18 delivers energy through shaft 19, Worm 20 and worm gear 21 into shaft 22 to chain sprocket 23. A flexible drive chain 24 connecting

sprockets

23 and 15 causes rotation of driving shaft 14 in the same manner as does motor 17.

This manually integrated and actuating mechanism comprising shaft 19 and worm 20 is supported in such a manner that worm is maintained in continuous engagement with worm gear 21 which is supported by but not permanently attached to shaft 22. To shaft 22 are fastened

pins

25, 26, 27, 28 and 29. Pin 28 engages a slot 30 in hub 31 of worm gear 21 at all times while pins 25 and Z9 may be caused to engage a slot 32 in hub 33 of sprocket 23 and a slot 34 in a hub 35 of rotatably mounted racking crank 36 by displacing shaft 22 to the left and right respectively as shown in FIGS. 3 and 4.

Displacement of shaft 22 is effected by movement of a selector lever 4t) acting through a pin 41 and a block k42. Block 42 is supported by but not attached to shaft 22 and pin 41 extends from block 42 into a loose fitting aperture in lever 40. Block 42 is contained between

pins

26 and 27 on shaft 22. In the position shown in FIG. 2 handle 18 is inoperative as far as conveying motion to driving shaft 14 since shaft 22 is disengaged from sprocket 23. In the manual driving position lever 40 is moved from the position shown in FIG. 2 to the left as shown in FIG. 3 so that shaft 22 and sprocket 23 are interconnected. During the time that handle 18 is rotated to drive shaft 14 the shaft of the electric motor 17 is also rotated because they are directly connected together. Further, during the time that motor 17 is driving shaft 14, sprocket 23 and chain 24 are also driven although at this time lever 40 has disconnected shaft 19 from shaft 14.

Rotation of driving shaft 14 and gear 16 by chain 24 causes rotation of a gear 45 which is in meshing engagement therewith and, for` example, may be rotatably mounted on a bearing pin or shaft 46. Gear 4S is provided with a driving pin 47 positioned to engage with a corresponding pin 48 on an eccentric 4?. Eccentric 49 is supported by shaft 46 for rotation thereon. Rotation of gear 45 engages pin 47 on gear 45 with pin 4S on eccent-ric 49 and revolves eccentric 49 clockwise as shown in FIG. l about its fixed center, which is the center of shaft 46, vdri-ving a connecting rod 5@ to the right. Connecting rod 5t) is iixedly mounted on a housing 51 supported by eccentric 49 and rotatably movable therewith during at least a part of the cycle of rotation of eccentric 49, ias well known in the art.

The motion of connecting rod Si) to the right compresses a pair of load springs (stored energy devices) 52 and S3 as shown in FIGS. 1 and 2 that function as a unit through link mechanism 54 and bar 55. At the instant that springs '52 and 53 are fully charged, latch roll 556 affixed to housing 51 engages a prop latch 57, thus holding the fully charged springs latched and ready to be discharged to perform a useful function,'for example,

aeration closing the movable cooperating arcing contacts '7o and 71 of a circuit breaker. The prop latch 57 may be released by a solenoid mechanism 6@ which upon movement of its armature rod 61 to the right as shown in l actuates prop latch 57 through a lever 62 and shaft 62 torotate it clockwise releasing latch roll 56, housing 51 and connecting rod Sti to rotate under the force of

springs

52 and 53. Once the stored energy or

load springs

52 and 53 have been released the springs can again be recharged automatically by moto-r 17 or handle 18 as explained above.

To prevent overloading of the spring charging system when latch roll 56 engagesV prop latch v57, gear 45 which is driven by the driving shaft 14 is shaped to discngage from gear 16 on shaft 14 at the fully charged position of the

stored energy springs

52 and 53. This disengagement is accomplished by the removal of a segment of the teeth from the periphery of the gear. Flexible teeth 63 (shown in FIG. l) are provided at the end of the open segment to facilitate reengagement of the gears 16 and at the beginning of each cycle of meshing engagement. As pin 4S on eccentric 49 is moved clockwise to the left as shown in FIG. l when connecting rod is released for utilizing the stored energy of

springs

52 and 53, gear 45 becomes free to rotate and is caused to reengage with gear 16 yand driving shaft 1 4 by a spring 64 Iattached to a bias lever 65 which acts against a pin 66 fixed to gear 45.

The flexible teeth 63 are detachably mounted along only a porti-on of a second part of the periphery of gear 45 by means of bolts 67 which may threadly engage with suitable openings along the periphery of the gear structure. Teeth 63 are shown as formed of overlapping met-allic strip material of resilient properties which are so arranged as to have spaced tooth gear edges. The span of flexible teeth are arranged in the open segment of the tooth periphery of gear 45 adjacent one end of the normal gear teeth 68 of gear 45. Gear teeth 68 arranged along a rst part of the periphery of gear 45 have solid tooth segments while teeth 63 are flexible so as to yield if necessary upon engagement with the teeth on pinion or gear 16 or upon initial movement of shaft 14 to automatically position gears 16 and 45 in proper meshing engagement at the sta-rt of each driving cycle of shaft 14. This arrangement of flexible teeth Iat .the beginning part of a span of teeth provides unimpeded reengagement of the charging motor pinion gear 16 with the charging mechanism for

springs

52 and 53 immediately after each energy releasing action of the prop latch mechanism 57.

As shown in FIG. 5 the arcing contact mechanism including the pair of cooperating contacts 70 and '71 are in the contact closed position before the stored energy springs 52 and 53 are charged by the electric motor 17.

Springs

52 and 53 are connected to the arcing contacts by means of a bell crank 72 pivotally mounted Iat 73 to the frame of the circuit breaker. One end of bell crank 72 is pivotally connected by pin '74 to link mechanism 54 and by a pin 75 to link 76. Link '76 is pivotally connected at 69 to a rotatable closing cam 77 which acts agaisnt toggle roll 78 moving a toggle link-age comprising toggle arms 79 and 80 to the right as `shown in FIG. 5 about a releasable center point S1 to close the arciug contacts. When the arcing contacts are in their closed position the toggle is arranged in an -overcenter position in the usual manner. The closing cam 77 will remain in its upper position reached when forcing the toggle linkage to its overcenter position until the closing springs 52 and 53 are recharged. Recharging of the closing springs 52 and 53 will rotate bell crank 72 in the counterclockwise direction to the position shown in FIG. 1 thereby drawing the closing cam '77 down to the position for another arcing contact closing operation.

The opening and closing of the arcing contacts by the toggle linkage comprising the toggle arms 79 and 80 cause rotation of a lever arm which is connected at Opening (tripping) of the circuit breaker contacts 70 l and 71 from the position shown in FIG. 5 to the position shown in FIG. 1 is accomplished by the release of trip latch 94. Trip latch 94 is held in the position shown in FIG. 5 by a trip shaft 95. Shaft 95l has a given contour such that in one position it holds trip latch 94 in a given position and when rotated to another position releases the latch. Trip shaft 95 is rotated counterclockwise by action of a shunt or overcurrent trip device 96 or a manual trip device 97. This rotation of the trip shaft 95 permits trip latch 94 to rotate counterclockwise about its fixed center 98 by the load bias of toggle latch 99. Thus, toggle latch 99 is released and permitted to rotate clockwise about center 100 under the bias of spring 93. Releasably restrained center 81 is now free to rotate with the toggle latch 99 permitting the force of spring load 93 to move crank or lever arm 90y clockwise to collapse the toggle formed by toggle arms 79 and 80 to the position shown in FIG. 1. The rotation of arm 90 and movement of a link 102, connecting toggle arm 79 and arm 90 to the movable arcing contact 70, to the left, opens the circuit breaker contacts. The resetting sequence of the trip latch 94, toggle latch arm 90, and toggle linkage comprising toggle arms 79 and 80 is dependent on the position of the stored energy springs 52 and 53. With the

springs

52 and 53 charged, the latches and toggle mechanism will immediately be reset by the bias of spring 101 as shown in FIG. 1. With the

springs

52 and 53 discharged, the closing cam 77 will hold the toggle mechanism trip free as shown in FIG. 6 until the charging sequence is started at which time the closing cam will be withdrawn permitting the toggles and latches to reset.

FIG. 6 shows the mechanism in the trip free position. When latches 94 and 99 are released, center 81 is not restrained as in the normal closing operation, but is released to pivot about center 100. Thus, when closing energy is delivered to the toggle linkage through the closing cam 77, the toggle latch arm 99 rotates clockwise about the new center 100 permitting the closing cam 77 to go through its complete cycle without moving link 102, and the breaker contacts therefore will not close. This action can take place during any part of the closing stroke, causing movable contact 70 to immediately return to the open position even though the stored energy springs 52 and 53 are acting to close the mechanism.

When the circuit breaker is mounted in or removed from a cubicle 8S the circuit breaker is racked in and out by the racking mechanism 12. Racking mechanism 12 comprises a pair of pivotally mounted racking cranks 82 (one of which is shown in FIG. 1) each provided with a slot 83 at one end thereof for engaging with fixed pins 86, one of which is shown in FIG. 2 attached to the side of cubicle 8S. Cranks 82 are fixed to a driven shaft 84 and are rotated by an arm 35 also xed to shaft 84. Arm S5 is actuated by racking crank 36 through racking links 57. Racking crank 36 is rotatably mounted on shaft 22.

In order to actuate the racking mechanism 12 the selector lever 40 is moved to the packing position shown in FIG. 4. In this position shaft 22 is moved to the right and pin 29 engages with slot 34 of hub 35 of arm 36. Upon rotation of shaft 22, arm 36 is rotated to actuate cranks 82 to rack the breaker in or remove it from the cubicle.

In accordance with the structure described and shown in the drawings with the selector lever in the neutral or vertical position, a suitable control switch 105 energizes the electric motor 17 whenever the stored energy springs 52 and 53 are in their discharged or extended position, then motor 17 rotates shaft 14 and gears 16 and 45. Rotation of gear 45 engages pin 47 with pin 48 on eccentric 49 which revolves eccentric 49 clockwise about shaft 46 ldriving the connecting rod 5t] to the right. The motion of the connecting rod 50 tothe right compresses springs 52 and 53. At the instant springs 52 and 53 are fully charged, latch roll 56 aflixed to connecting rod housing 51 engages prop latch 57 thus holding the fully charged springs latched and ready to be discharged to close the breaker by release of prop latch 57 by the solenoid mechanism 60. Once the stored energy springs 52 and 53 have been released and the breaker closed, they are again recharged automatically by the motor drive unit, thereby providing a standby supply of stored energy, if the selector lever 40 is in the neutral position.

Manual charging of the stored energy springs 52 and 53 is accomplished by moving the selector lever 40 to the charge position shown in FIG. 3 and rotating handle 18 counterclockwise to engage shaft 22 through pin 25 to sprocket 23. This action now makes the handle an integral part of the charging scheme. Rotation of handle 18 delivers energy through shaft 19, worm 20 and worm gear 21 into Shaft 22 and to chain sprocket 23. A flexible drive chain 24 connecting sprocket 23 and sprocket or gear 15 causes rotation of pinion 16 in the same manner as motor 17. The remainder of the sequence for charging and discharging

springs

52 and 53 is the same as above described under the motor energized sequence of this structure.

Manual release of the stored energy springs 52 and 53 to close the arcing contacts 70 and 71 is accomplished by depressing mechanical closing button 90' which rotates prop latch 57 in .the same manner as solenoid mechanism 60. Once released and the breaker contacts closed the

springs

52 and 53 may be again recharged manually as previously described.

To rack the circuit breaker structure into its energized position in the cubicle the selector lever 40 is placed in the neutral position and the breaker is moved into the cubicle until the slots in the racking cranks 82 engage with fixed pins 86 attached to the sides of the cubicle. To reach the racking position in the cubicle the bias of

springs

52 and 53 must be released and certain stops or interlocks in the cubicle overcome in a predetermined manner. .Once these interlocks are overcome in given positions in the cubicle the breaker contacts can be closed or opened. The breaker racking action occurs by rotating cranks 82 which are fixed to shaft 84 and are rotated by arm 85. Arm 8S is actuated by shaft 22 through racking crank 36 and links 87.

Although but one embodiment of the present invention has been illustrated and described, it will. be apparent to those skilled in the art that Various changes and modifications may be made therein Without departing from the spirit of the invention or from the scope of the appended claims.

Having now particularly described and ascertained the nature of my said invention and the manner in which it is to be performed, I declare that what I claim is:

1. A circuit breaker structure comprising in combination a pair of cooperating movable arcing contacts, spring means for closing said arcing contacts upon bias thereof, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing said opening spring means during closing of said arcing contacts, rotary shaft means for biasing said closing spring means, and means for triggering said opening spring means to open said arcing contacts.

`2. A circuit breaker structure comprising in combina- Y 6 tion a pair of cooperating movable arcing contacts, spring means for closing said arcing contacts upon bias thereof, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing ksaid opening spring means during the release of the bias of said closing spring means, means for biasing said closing spring means comprising a rotary driven shaft and a mechanism for converting the motion of said driven ,shaft in linear motion for biasing said closing means, and means for triggering said opening spring means to open said arcing contacts.

3. A circuit breaker structure comprising in combination a pair of cooperating movable arcing contacts, spring means for closing said arcing contacts upon bias thereof, means for biasing said closing means comprising a rotary driven shaft and a mechanism for converting the motion of said driven shaft in linear motion for biasing said closing means, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing said opening spring means during closing of said arcing contacts, and means for triggering said opening spring means to open said arcing contacts.

4. A circuit breaker structure comprising in combination a pair of cooperating movable arcing contacts, spring means for 4closing said arcing contacts upon bias thereof, means for biasing said closing means comprising a first driving shaft, a second shaft, a first gear fastened on said driving shaft, a second gear mounted on said second shaft, said rst and second gears being in meshing engagement, said second gear upon rotation thereof biasing said closing means, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing said opening spring means upon closing of said arcing contacts, and means for triggering said opening spring means to open said arcing contacts.

5. A circuit breaker structure comprising in combination a pair of cooperating movable arcing contacts, spring means for closing said arcing contacts upon bias thereof, means for biasing said closing means comprising a first driving shaft, a second shaft, a rst gear fastened on said driving shaft, a seond gear mounted on said second shaft, said first and second gears being in meshing engagement during at least a part of their rotation, said second gear upon rotation thereof biasing said closing means, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing said opening spring means upon closing of said arcing contacts, and means for triggering said opening spring means to open said arcing contacts.

6, A circuit breaker structure comprising in combination a pair of cooperating movable arcing contacts, spring means for closing said arcing contacts upon bias thereof, means for biasing said closing means comprising a iirst driving shaft, a second shaft, a rst gear fastened on said driving shaft, a second gear mounted on said second shaft, said first and second gears being in meshing engagement during at least a part of their rotation, said second gear being provided with a gear track of a given length, said second gear upon rotation thereof biasing said closing means, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing said opening spring means upon closing of said arcing contacts, and means for triggering said opening spring means to open said arcing contacts.

7. A circuit breaker structure comprising in combination a pair of cooperating movable arcing contacts, spring means for closing said arcing contacts upon bias thereof, means for biasing said closing means comprising a first driving shaft, an electric motor connected to said driving shaft for rotation thereof, means for selectively energizing said motor, a second shaft, a first gear fastened on said 7 `driving shaft, a second gear mounted on said second shaft, said rst and second gears being in meshing engagement during at least Ya part of their rotation, said second gear being provided with a gear track of a given length, said second gear upon rotation thereof biasing said closing means, spring means for opening said arcing contacts upon bias thereof, said closing spring means being connected to said opening spring means for biasing said tacts, and means for triggeringsaid opening spring means to open said arcing contacts.

References Cited in the file of this patent opening spring means upon closing of said arcing con- 10 2,909,629

UNITED STATES PATENTS Rea Apr. 12, 1932 Thumim Dec. 5, 1933 Nette Apr. 17, 1934 Lingal etal June 30, 1953 McCloud Oct. 20, 1959

Claims

1. A CIRCUIT BREAKER STRUCTURE COMPRISING IN COMBINATION A PAIR OF COOPERATING MOVABLE ARCHING CONTACTS, SPRING MEANS FOR CLOSING SAID ARCING CONTACTS UPON BIAS THEREOF, SPRING MEANS FOR OPENING SAID ARCING CONTACTS UPON BIAS THEREOF, SAID CLOSING SPRING MEANS BEING CONNECTED TO SAID OPENING SPRING MEANS FOR BIASING SAID OPENING SPRING MEANS DURING CLOSING OF SAID ARCING CONTACTS, ROTARY SHAFT MEANS FOR BIASING SAID CLOSING SPRING MEANS, AND MEANS