US2949516A

US2949516A - Reposition terminals for circuit breaker base extension

Info

Publication number: US2949516A
Application number: US623883A
Authority: US
Inventors: Edmunds William Harold
Original assignee: ITE Circuit Breaker Co
Current assignee: ITE Circuit Breaker Co
Priority date: 1956-11-23
Filing date: 1956-11-23
Publication date: 1960-08-16
Anticipated expiration: 1977-08-16

Description

Aug. 16, 1960 REPOS Filed NOV. 23, 1956 W. H. EDMUNDS ITION TERMINALS FOR CIRCUIT BREAKER BASE EXTENSION 4 Sheets-Sheet l Arman 6% Aug. 16, 1960 w. H. EDMUNDS REPOSITION TERMINALS FOR CIRCUIT BREAKER BASE EXTENSION 4 Sheets-Sheet 2 Filed Nov. 23, 1956 Aug. 16, 1960 Filed NOV. 23, 1956 W H. EDMUNDS REIPOSI'I'ION TERMINALS FOR CIRCUIT BREAKER BASE EXTENSION 4 Sheets-Sheet 3 I DJ gamma vs A frat V 76 1 1960 w H. EDMUNDS 2,949,516

REPOSITION TERMINALS FOR CIRCUIT BREAKER BASE EXTENSION Filed Nov. 23, 1956 4 Sheets-Sheet 4 ll 36 ll 33 w 70 76 W WM ,zwza Mm W W BY M I W United States Patent REPOSITION TERMINALS FOR CIRCUIT BREAKER BASE EXTENSION William Harold Edmunds, Havertown, 'Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Nov. 23, 1956, Ser. No. 623,833

Claims. (Cl. 200-114) My invention relates to a circuit interrupter of the type shown in my copending applications Serial No. 461,378, filed October 11, 1954, and Serial No. 622,042, filed November 16, 1956, wherein a current limiting device and series connected circuit breaker are electrically and mechanically coordinated and is more specifically related to a terminal construction for the above noted type of device wherein its terminals have the same positioning as the terminals of the standard circuit breaker.

The combination of a series connected circuit breaker and current limiting device has been set forth in my copending application Serial No. 461,378, above noted, and a construction wherein the current limiters and circuit breaker are placed inindividual housings which are removably connected to one another is set forth in copending applications Serial No. 472,969, filed December -3, 1954, now Patent No. 2,888,535, and Serial No. 622,042, above noted.

In essence, this combination allows the use of a circuit breaker having a lower interrupting rating than the short circuit capacity of the circuit breaker wherein the circuit breaker is provided with thermal trip units for opening a circuit after prolon ed overloads and an instantaneous trip unit for opening the circuit under relatively low fault values. When a strong fault appears or a fault which exceeds a predetermined cross-over point, the series connected current limiting fuse operates to interrupt the circuit rather than the circuit breaker which may not be large enough to interrupt this fault value. v

As well as being electrically coordinated as seen above, the two devices are also mechanically coordinated in that operation of the current limiting fuse of any phase (when operating in a multiphase system) will automatically trip the circuit breaker contacts of each phase.

As set forth in the above noted application Serial No. 622,042, the base of a standard circuit breaker may be extended and provided with disconnect contacts so that current limiting devices may be mounted in series with the circuit breaker by disconnect contact engagement between a circuit breaker trip unit disconnect contact and the additional contact attached to the base. Hence, the terminals of the combined interrupter will be the original circuit breaker terminal on the circuit breaker side away from the base while the second terminal will be aligned with the disconnect contact added to the base extension of the circuit breaker. Thus the distance between the first and second current interrupter terminals is now greater than the distance between the original terminals of the circuit breaker and it will be impossible to mount this adapted current interrupter in a switchboard having terminal distances which are given'by the terminal spacing of the standard circuit breaker device.

That is to say, the switchboard terminals which could be of the plug-in type having protruding studs extending from their mounting blocks are spaced from one another so that the spacing distance exactly corresponds to the terminal spacing of the standard type circuit breaker. When, however, a base extension is utilized for mounting the current limiting devices at the end of the circuit breaker as set forth in application Serial No. 622,042 the terminal spacing of the current interrupter is increased and it would therefore require a new panel board construction wherein the terminal spacing is increased accordingly.

The principle of my invention is to construct a base extension which could be an added member or could be an integral part of the circuit breaker base for a circuit breaker wherein the disconnect contact of the extension is electrically connected to a second disconnect contact on the bottom of the circuit breaker base which is in registering alignment with the original circuit breaker trip unit terminal. Thus in my novel construction, the terminal spacing of a circuit breaker which is electrically and mechanically coordinated with a current limiting device will be exactly the same as that of the circuit breaker itself. Hence in an existing installation, it is now only necessary to remove the standard type of circuit breaker and replace it with the current interrupting device set forth in application Serial No. 622,042 without disturbing the bus or cable connections in the back of the switchboard.

Accordingly, a primary object of my invention is to construct the base extension of a combined circuit breaker and current limiting device so that the terminal spacing will be the same as the terminal spacing of the circuit breaker itself.

Another object of my invention is to provide a novel construction wherein standard types of circuit breakers and circuit breakers adapted to be coordinated with current limiting fuses are interchangeably connected to a given panel board.

These and other objects of my invention will become apparent from the following description taken in connection with the drawings in which Figures 1 and 1A are perspective views showing a circuit interrupting device comprising a circuit breaker contained within a first housing and a current limiting device contained within a second and removable housing.

Figure 2 is an exploded perspective view of the current limiting device and housing of Figure 1.

Figure 3 shows a cross-sectional view through one phase of Figure 1.

Figure 4 shows a fragmentary top view of Figure 3 where a pin is inserted in the interlock rod to defeat the interlock.

Figure 5 is a second embodiment of my novel invention.

Figure 6 is an enlarged view in cross-section of the base construction of Figure 4-.

Referring first to Figure 1, a circuit breaker housing 20 has an extension 21 connectible to one end thereof by means of screws such as

screws

24 and 25 which pass through openings 28 and 29 respectively, which fasten into cooperating openings in circuit breaker housing 20.

if desired, extension 21 could be an integral part of the circuit breaker base as is shown in Figure 1A.

In this application, therefore, the extended base is intended to mean either an extra component added to a base or an extension which is an integral partof the base.

Contained with circuitv breaker housing 20 is an 'operating mechanism of any desired type such as that shown in my U.S. Patent No. "2,574,093 which is operable by operating handle 30 for operating a pair of contacts for each phase of the circuit breaker. Each of the pairs of contacts of each phase is then terminated on one side by

disconnect contacts

31, 32 and a contact 33, which cannot be seen in Figure ljrespectively.

The extension -21 provides additional

disconnect contacts

34, 35 and 36 which cooperate with

contacts

31, 32 and 33 respectively for connecting a current limiting device in series with each of the circuit breaker phases.

Each of

disconnect contacts

31 and 36 are of the tulip clip type such as that described in copending application Serial No. 536,586, filed September 26, 1955, and assigned to the assignee of the instant invention, which are constructed to receive a stud in electrical and mechanical engagement.

However, disconnect contacts 31 through 36 could be of any desired type.

Current limiting devices for cooperating with each of the circuit breaker phases are housed within housing 37. Figure 2 more specifically shows these current limiting devices as fuses 38, 39 and 40 which are provided with disconnect studs 41-42, 4344, 45-46 respectively. As seen in Figure 1, fuse 40 is connected to its corresponding phase by connection of

disconnects

41 and 42, and

disconnects

36 and 33 respectively. In a similar manner, disconnects 43, 44 and 45, 46 of Figure 2 will,

cooperate with

disconnects

35, 32 and 34, 31 respectively of Figure 1.

Fuses 38, 39 and 40 are maintained in housing 37 by retaining plate 47 which is fastened to housing 37 by screws 48 and 49 as seen in Figure 2 and described in copending application Serial No. 582,552, filed May 3, 1956, now Patent No. 2,905,791 and the assembled housing is connected to the circuit breaker housing by

screws

50 and 51 which pass through

apertures

52 and 53 respectively and into tapped openings 54 and 55 of extension 21 as seen in Figure 1.

As may be seen in the above noted copending application Serial No. 472,969 each ot fuses 38, 39 and 40 are provided with a striker pin such as striker pin 85 of fuse 40 which is ejected from the fuse upon operation thereof. The striker pins are positioned to pass through a cooperating aperture in its respective disconnect, such as aperture 56 of disconnect 42 which cooperates with striker pin 85.

An auxiliary tripper bar 57 is pivotally mounted within housing 37 as seen in Figures 1 and 2 and as best seen in Figure 2, tripper bar 57 as extensions 58, 59 and 60 thereon which are positioned to be engaged by the striker pins of fuses 38, 39 and 40 respectively upon operation thereof.

A further extension 61 is fastened to auxiliary tripper bar 57 which, as will be seen hereinafter, is biased into operative engagement with the tripper bar of the circuit breaker by biasing spring 61a.

Figure 3 shows a cross sectional view of the assembled components of Figure 1 when taken through the phase including fuse 40.

As seen in Figure 3 which shows screw 24 fastened to circuit breaker housing 20, a tulip clip type contact 62 is electrically connected to contact 36 and is fastened within housing 21 in any desired manner. Clearly, a set of disconnects similar to disconnect 62 will be provided for each of

disconnects

34 and 35.

The circuit breaker is provided with a similar set of disconnects such as disconnect contact 63 wherein disconnects 62 and 63 cooperate for plug in engagement with

studs

64 and 65 respectively of

mounting blocks

66 and 67 which may be fastened within a switch board. Clearly, each of the other phases will be provided with similar sets of disconnects for cooperating with corresponding mounting blocks.

As an alternative, Figure 3 shows that a straight terminal 68 could be brought out as seen in dotted lines where connection to the current interrupting device is made at lead connecting means 69.

The current path of the phase shown in Figure 3 ineludes stud 65, circuit breaker tulip clip 63, stationary contact 70, movable contact of contact arm 71, a pigtail (not shown) which connects contact arm 71 to conductor 72, heater 73, coil 74, conductor 75, tulip clip 33, stud 42, fuse 40, stud 41, tulip clip 36, tulip clip 62, and stud 64.

Coil 74 has a pivotally mounted armature 76 and a plunger 77 associated therewith, these components comprising the magnetic trip unit. Heater 73 has bimetal 78 and adjusting screw 79 associated therewith, these components comprising the thermal-trip unit.

A tripper bar 80 is then seen in Figure 3 as having member 81 fastened thereto which carries adjusting screw 79 in cooperating alignment with bimetal 78 and is itself aligned with plunger 77.

Member 81 has one end thereof protruding into slot 82 of trip rod 83 and is rotatable in a counterclockwise direction within slot 82.

The operating mechanism 84 has a latch member 85 connected thereto and constructed to be latched by tripper bar 80. When tripper bar 80 is rotated in a counterclockwise direction, however, latch member 85 will be unlatched to allow mechanism 84 to disengage the circuit breaker cooperating contacts of each phase since mechanism 84 is constructed to be common to each phase.

In the event of a prolonged overload, heater 73 will cause bimetal 78 to deflect into engagement with screw 79 to cause counterclockwise rotation of tripper bar 80 and tripping of the circuit breaker contacts.

Under fault conditions, coil 74 will create a strong magnetic field to cause armature 76 to drive plunger 77 into engagement with member 81, thus rotating bar 80 counterclockwise to effect instantaneous tripping of the circuit breaker contacts.

Figure 3 further shows the striker pin 85' of fuse 40 as being positioned in registry with aperture 56in disconnect 42 and extension 60 of auxiliary tripper bar 57 (see Figure 2).

When fuse 40 is operated (on faults above a predetermined value), striker pin 85' is ejected into engagement with extension 60 to rotate auxiliary tripper bar 57 (Figure 2) clockwise against the biasing force of spring 61a. This rotation will then remove extension 61 from trip 85a of trip rod 83 and allow biasing spring 86 to drive trip rod 83 to the left and rotate tripper bar 80 counterclockwise for tripping the circuit breaker contacts.

Thus, upon operation of one of the current limiting fuses such as fuse 40, the circuit breaker contacts will be disengaged to prevent single phasing and to disconnect the circuit.

It is important to note that the same action would be obtained if the fuse housing 37 were disconnected from the circuit breaker housing 20. That is, extension 61 of tripper 'bar 57 would be removed from tip 85a of link 83 to allow subsequent rotation of tripper bar 80.

Hence, in this construction wherein the fuse housing 37 is connected at the end of circuit breaker housing 20, the circuit breaker cooperating contacts will be disengaged responsive either to operation of any of the fuses or to removal of the fuse housing.

In the case of Figure 3, it is seen that the spacing between

switchboard mounting blocks

66 and 67 and their

studs

64 and 65 respectively is determined by the relative spacing between

terminals

62 and 63. If the circuit breaker 20 were a standard circuit breaker and did not include the extended base 21, however, the terminal spacing would be given by terminals 63 and a terminal which would be in registry with circuit breaker disconnect contact 33. Thus, in adding the base extension 21 and its disconnect contact 36 to circuit breaker 20, the terminal spacing of the device is increased over that of the circuit breaker itself. Hence, if the circuit breaker 20 of Figure 3 had been previously mounted in a switchboard by disconnects such as 63 and a disconnect in registry with disconmeet 33, the panel board would have (to be considerably altered in order to accommodate the increased terminal spacing.

Figure 4 specifically illustrates my novel invention and the manner in which my novel invention

allowsthe connecting blocks

66 and 67 and their

corresponding studs

64 and 65 respectively to be connectible to either a standard circuit breaker or to a circuit breaker having a base extension for mounting fuse devices as shown in Figure3.

It is to be noted that in the following description; the use of tulip type disconnects is set forth for illustrative purposes. However, my novel invention would be applicable with the use of any type of terminal construction.

In the case of Figure 4, it is seen that disconnect 36 which is fastened to the extended base 21 has a current conducting member 90 connected to tulip clip 62 which is now offset to be in registry with terminal 33.

Figure 5 which is a bottom view of Figure 4 shows that the tulip clip type disconnects 91 and 92 for the other two phases of the three phase device of Figure 4 are offset in a manner similar to that shown for terminal 62 and are connected to their

corresponding disconnects

35 and 34 re-' speetively by connecting

members

93 and 94 respectively. Clearly, terminals 91 and 92 will be in registering relationship or coaxial relationship with respect to the circuit breaker trip unit disconnects which may be seen as

disconnects

32 and 31 respectively in Figure l.

The manner in which connecting member 90 is supported within the base extension 21 may be best seen in Figure 6 which shows a fragmentary cross-sectional view along the lines 66 of Figure 5.

Thus, Figure 6 shows the jumper 90 as being maintained against the current carrying bushing 95 by means of bolt 96 which is in threaded engagement with stud 97. Stud 97 as shown in Figure 6 is engageable with tulip clip 36. Hence, the threaded engagement between bolt 96 and stud 97 maintains a portion of jumper 90 in both electrical engagement with stud 97 and mechanical engagement with housing 21. Further mechanical support for jumper 90 may be obtained by screw means 98 which is threaded into housing 21.

Jumper 90 is terminated by a stud 99 which is in registry with stud 100 which has circuit breaker trip unit disconnect 33 attached thereto, stud 100 being connected to conductor 75 which, as seen in Figure 3, is connected to the trip mechanism of the circuit breaker.

Stud 99 then has the tulip clip type disconnect 62 secured thereto by the garter spring 101 in the manner set I forth in the Us. Patent 2,805,294 issued to W. H. Ed-

munds entitled Mounting Block for Circuit Breaker and the other end of disconnect 62 is adapted to receive a stud connecting means such as stud 64 of Figure 4 of the mounting block 66.

It is now clear with reference to Figures 4, 5 and 6 that the combined circuit breaker and current limiter will have the same terminal spacing as does a standard circuit breaker since these terminals are in registry with the standard circuit breaker terminal positions. Thus, as seen in Figure 4, the same switchboard construction which includes mounting

blocks

66 and 67 may be used to mount either standard circuit breakers or circuit breakers co ordinated with current limiting devices mounted on an extended base of the circuit breaker.

Although I have here described preferred embodiments of my novel invention, many modifications and variations will now be apparent to those skilled in the art. I prefer therefore to be limited not by the specific disclosure herein, but only by the appended claims.

I claim:

1. In combination; a circuit breaker having an extended base and a terminal; said circuit breaker having a pair of cooperable contacts movable between an engaged and a disengaged position, and a disconnect contact; said disconnect contact being in registry with a circuit breaker terminal position; said extended base carrying a disconnect contact; said circuit breaker disconnect contact and said extended base disconnect contact being constructed to electrically connect a current limiting device in series with said pair of cooperating contacts when corresponding disconnect contacts of said current limiting device engage said circuit breaker and base disconnect contacts; said terminal being electrically connected to said extended base disconnect contact and positioned in registry with said circuit breaker disconnect contact.

-' 2. In combination; a circuit breaker having an extended base anda terminal; said circuit breaker having a pair of cooperable contacts movable between an engaged and a disengaged position, trip mechanism for mechanically coordinating said circuit breaker with a current limiting device, and a disconnect contact; said disconnect contact being in registry with a circuit breaker terminal position; said extended base carrying a disconnect contact; said circuit breaker disconnect contact and said extended base disconnect contact being constructed to electrically connect a current limiting device in series with said pair of cooperating contacts when corresponding disconnect contacts of said current limiting device engage said circuit breaker and extended base disconnect contacts; said termi nal being electrically connected to said base disconnect contact and positioned in registry with said circuit breaker disconnect contact; panel boards being adapted for plugin arrangement with said circuit breaker alone being cooperable with said current interrupter having the same terminal position.

3. In combination; a circuit breaker having an extended base and a terminal; said circuit breaker having a pair of cooperable contacts movable between an engaged and a disengaged position and a disconnect contact; said circuit breaker having a first and second terminal position at either end thereof; said first terminal position being at the end of said circuit breaker opposite said extended base end; said extended base carrying a disconnect contact; said circuit breaker disconnect contact and said extended base disconnect contact being constructed to electrically connect a current limiting device in series with said pair of cooperating contacts when corresponding disconnect contacts of said current limiting device engage said circuit breaker and extended base disconnect contacts; said terminal being electrically connected to said base disconnect contact and positioned in registry with said circuit breaker second terminal position.

4. In combination; a multiphase circuit breaker having an extended base and a terminal for each phase; each phase of said circuit breaker having a pair of cooperable contacts movable between an engaged and a disengaged position, and a disconnect contact; each of said disconnect contacts being in registry with corresponding circuit breaker terminal positions; said extended base carrying a disconnect contact for each phase of said multiphase circuit breaker; each of said circuit breaker disconnect contacts and said extended base disconnect contacts being constructed to electrically connect a current limiting device in series with corresponding pairs of cooperating contacts when corresponding disconnect contacts of said current limiting device engage said circuit breaker and extended base disconnect contacts; each of said terminals for each phase being electrically connected to a corresponding base disconnect contact and positioned in registry with a corresponding circuit breaker disconnect contact.

5. In combination; a circuit breaker having an extended base and a terminal; said circuit breaker having a pair of cooperable contacts movable between an engaged and a disengaged position, and a disconnect contact; said disconnect contact being in registry with a circuit breaker terminal position; said extended base carrying a disconnect contact; said circuit breaker disconnect contact and said extended base disconnect contact being constructed to electrically connect a fusible device in series with said pair of cooperating contacts when corresponding disconnect contacts of said fusible device engage said circuit breaker and extended base disconnect contacts; said termi- References Cited in the file of this patent UNITED STATES PATENTS Auel et al Nov. 1, 1910 Van Valkenburg July 3, 1917 Wyrnan Oct. 13, 1925 10 Milano Oct. 2, 1928 Benjamin Feb. 5, 1929 8 Corbett Mar. 2, 1937 Schmidt Feb. 27, 1940 Linde May 27, 1941 Dannenberg Sept. 28, 1943 Cataldo et a1. May 13, 1947 Dannenberg June 14, 1949 Spiro July 12, 1949 Kozacka May 28, 1957 Swain et a1. July 23, 1957 FOREIGN PATENTS Great Britain Apr. 25, 1935