US2711460A - Support structure for gas blast circuit breaker - Google Patents

Description

June 1955 v. 1. TILLI EIAL SUPPORT STRUCTURE FOR GAS BLAST CIRCUIT BREAKER 2 Sheets-Sheet 1 Filed Feb. 5, 1952 Inventors: Vincent L.TiHi Milton L.

Heintz, by Them Attorney June 21, 1955 v. L. TILL] ET AL 2,711,460

SUPPORT STRUCTURE FOR GAS BLAST CIRCUIT BREAKER Filed Feb. 5, 1952 2 Sheets-Sheet 2 Vincent L.T'| Hi, Milton L.Heintz, by MW Their Attorney.

United States Patent Office 2,711 ,469 Patented June 21, 1955 SUPPGRT STRUCTURE FOR GAS BLAST CIRCUIT BREAKER Vincent L. Tilli, Philadelphia, and Milton L. Heintz, Broomall, Pa., assignoi's to General Electric Company, a corporation of New York Application February 5, 1952, Serial No. 269,962

4 Claims. (Cl. 200-148) This invention relates to support structure for gas blast circuit breakers and, more particularly, to an improved arrangement for supporting a circuit breaker, its operating mechanism, and its air receiver, which structure is compact in construction and organized for maximum reliability of operation.

The invention in one form as applied to a gas blast circuit breaker comprises a rigid support structure including a pair of spaced-apart parallel support frames each having an opening therein, these openings being aligned for receiving with clearance therethrough a cylindrical fluid pressure tank which is suspended with limited resilience from the support frames, thereby permitting the tank to breathe without affecting the efiiciency of associated operating shafts and moving parts. The breaker together with its operating mechanism is mounted on or from the rigid support structure.

In gas blast circuit breakers it is common practice to utilize an air receiver for storing air or gas under pressure. Changes in ambient temperature, in the pressure in the tank, and other factors may cause the contour of the tank to change.

An object of this invention is to provide an improved support structure for a gas blast circuit breaker, its operating mechanism, and its air receiver which structure makes it possible for the receiver to expand or contract without materially interfering with the normal disposition of the breaker and its operating mechanism or with the valve operating mechanism used to control blasts of fluid to the breaker contacts.

The invention will be better understood from the following description taken in conjunction with the accompanying drawings in which Fig. 1 is a side view of a gas blast circuit breaker embodying the invention; Fig. 2 is a front veiw of the circuit interrupter shown in Fig. 1; Fig. 3 is an enlarged view of a portion of the blast valve operating mechanism; Fig. 4 is an enlarged view in section of a resilient support bracket which is secured both to the support frame structure and to the air tank for suspending the tank semi-rigidly in position; and Fig. 5 is a view of a portion of the trip-free linkage by means of which closing motion is imparted to the circuit breaker contacts during which the opening-spring devices are charged with energy.

'Jith reference to Figs. 1 and 2, the horizontal upper and lower metal angle bars 1 and 2 and the short and long vertical angle bars 3 and 4 form a pair of end supports. As is shown in Fig. 2, horizontal angle ties 5, 6, and 7 are interconnected between the long vertical corner angle-irons 4, while corresponding upper and lower horizontal tie pieces are interconnected between the short vertical corner angles 3. In addition, intermediate horizontal tie angles 8 and 9 are interconnected between the long vertical corner angle-irons 4. A diagonal angle strut 10 is used to brace the vertical corner angle 4 as is best seen in Fig. 1.

Mounted upon the basic supporting framework described above is a plurality of interrupting units generally designated by the numeral 11, an air receiver or tank generally designated by the numeral 12, and a solenoid operating mechanism generally designated by the numeral 13.

Each interrupting unit of the triple pole circuit breaker comprises a fixed contact 14 and a movable sickle-type contact 15 which is pivotally mounted at 16 to the terminal member 17 which in turn is secured about the mid portion of the insulating vertical blast conduit 18 which latter directs pressure fluid to each interrupting unit from the common tank 12. Contacts 14 and 15 are disposed within an arc chute structure 19 which is supported by a pair of spaced insulating cross arms 20 which in turn are braced by the insulating diagonal struts 21; these arms and struts being bolted to the basic framework at the horizontal tie angles 6 and 8 respectively. Mounted on a platform supported by the cross arms is an insulator 22 which in turn supports a resistor 23. One terminal of the resistor 23 is connected by means of conductor 24 to the fixed contact 14 and, by means of another conductor 25, the other terminal of resistor 23 is connected to a probe electrode 26 which terminates adjacent the movable contact 15 within the body of the arc chute 19. Resistor 23 functions to limit the magnitude of the are current and to preclude restrike in known manner during an interrupting operation as is set forth in United States Patent 2,284,842 to D. C. Prince et al. which is assigned to the assignee of this invention.

Secured to the transverse welded foundation channels of the basic supporting framework are a pair of support frames 27 and 28 which are bolted to these channels by the bolts 29 so as to be rigidly mounted thereon. In accordance with a feature of the invention, the air receiver or tank 12 is slung within the clearance openings 30 formed in the paired supporting frames 27 and 23 and is secured therein by the curved steel plate semi-rigid support brackets 31 which preferably are welded to the frame and to the air receiver. Preferably these brackets 31 are arranged in pairs with the brackets of each pair being diametrically disposed relative to tank 12. The details of the arrangement of the brackets 31 relative to the frame 27 and the receiver 12 are shown in Fig. 4, in section. As is obvious from Fig. 4, support frame 27, (and 28) constitutes a central plate web surrounded by a peripheral flange portion 32.

Mounted on top of the tank 12 are the three blast valves 33 each of which is arranged to control the flow of arc-extinguishing pressure fluid from the air receiver 12 through its associated insulating conduit 18.

As is obvious from Fig. l, the air receiver 12 is provided with an access opening which is normally sealed by a conventional cover 34. For purposes of isolating the tank 12 from its source of air under pressure as from a compressor or master tank, a valve 35, which is preferably of the non-return type, is provided.

The operating mechanism 13 supplies the actuating force for closing the contacts of the breaker and also, at the same time, for charging the springs for subsequently opening the breaker coincident with the opening of the blast valves. This mechanism as shown in the drawings incorporates a solenoid winding 36 having a reciprocable armature 37 therein. In the unenergized state, the armature 37 rests on cross pieces 38 which are affixed to downwardly extending support rods 39. Solenoid 36 and its armature 37 are disposed within an en circling magnetic structure 40 which is in turn supported upon appropriate vertical members of the basic supporting frame structure.

Energization of solenoid 36 by suitable circuit control means known in the art imparts upward motion to the armature 37 which in turn imparts closing movement to the circuit breaker. The operating linkage 42 interposed between the motive mechanism 13 and the breaker is shown in Fig. from which it will be seen that the armature 37 is provided with a plunger 4-1 which is arranged to drive the linkage 42 upwardly in such a manner as to impart counterclockwise rotation to the output crank 43 of the mechanism about its pivot 44. Crank 43 comprises a pair of rigidly interconnected arms 43a and 43b extending from opposite sides of pivot 44. In Fig. 5 the output crank 43 is shown as having been rotated counterclockwise about its pivot 44 into breaker-closed position, the armature 37 and plunger 4-1 having returned to their normally-withdrawn position due to the usual deenergization of the solenoid winding 36 when the breaker is in closed position. Pivot 44 comprises a square-sectioned shaft which is journally supported in the parallel vertically disposed support plates 45" as best seen in Fig. 2; and having outward extensions therefrom for accommodating the pair of overhung cranks of the opening spring devices thereon which will be described later.

Pivotally connected to the left hand end of the output crank 43 as viewed in Fig. 1 is a connecting rod 46 pivoted at 47 to a switch crank 48 which in turn is pivoted at 49 to an insulating operating rod 56 which is connected to the movable sickle-type contact 15 at 51. The switch crank 48 is rotatable about a fixed center 52 which takes the form of a long square-sectioned shaft extending across the three phases of the breaker for simultaneous operation thereof; it being understood that there are three two-armed bell cranks 58, one for each phase, as indicated in Fig. 2. Thus, having closed the breaker as depicted in the drawings, it will be appreciated that permitting clockwise rotation of output crank 43 about its fulcrum 44 (due, for example, to tripping of the linkage 42), under the opening action of biasing means yet to be described, imparts upward motoin to rod 46 and counterclockwise rotation to the three switch cranks 48 about their common shaft 52, thereby rotating the three contacts 15 about their pivots 16 to cause an opening operation of the breaker.

The linkage 42 comprises a guide link 53 which is mounted for rotation about a fixed pivot 54-, a first toggle link 55 and a second toggle link 56. Toggle link 55 is pivotally connected with guide link 53 at 57 and toggle links 55 and 56 are pivotally connected at their knee-joint by pin 53, the output crank or lever 43 being pivotally connected at its right hand end to the toggle link 56 at 59. A tripping roller 61 is provided at the pivot 57 and, in holding engagement therewith in the breakerclosed position is a trip latch 62. A closing roller 63 is supported on the toggle-knee pivot pin 58 for engagement by the solenoid plunger 41 during its energized upward closing stroke; and the roller also being engaged by the spring biased prop latch 64, which is pivotally mounted at 65, for holding this trip-free toggle linkage in the closed, or cocked, position. Thus, with the parts in the breaker-closed position shown in Fig. 5, tripping of the latch 62 due to counterclockwise rotation of its trip shaft 66 results in a collapse of the linkage mechanism to the left, thereby freeing the output crank 43 to rotate clockwise about its center of rotation 44 under the bias of the opening means thereby opening the breaker. The opening device of the operating mechanism comprises a spring 67 which is mounted within each of a pair of cylindrical enclosures 68 which are pivoted at 69 to the operating mechanism structure, each spring 67 being disposed about a rod 70 and being arranged to exert a downward force on the piston-like disc 71 aflixed to the lower end of the rod 70. Thus, when the breaker is tripped, springs 67 rotate the crank 43 in a clockwise direction, the extreme motion thereof being limited when the couplings 72 engage the resilient buffers 73. It will be readily understood that these opening spring devices are compressed and charged with energy when counterclockwise rotation is imparted to the output crank 43 so as to close the breaker contacts when the closing solenoid 36 is energized.

Controlled opening of the contacts 15 is obtained by means of the spring-dashpot devices 75. These dashpot devices 75, one per phase, are provided with a piston whose rod 76 is connected to the short arm of the switch crank 48 at the crosshead pin 47. Fluid-flow control means are provided for the devices which effectively regulate the contact opening movement of the contacts 15 so as to permit a fast initial opening movement followed by a slower movement thereof so as to prevent rebound of the contacts. In addition kickoff springs, not shown, for producing the fast initial contact separation may be incorporated within devices 75 to supplement the breaker opening action of the follow-up springs 67 promast valves to impart opening movement thereto against th action of the valve-closing springs 80. The normal position of valve operating shaft 77 and parts associa ed therewith is determined by the stop crank 81 whch is secured to the valve operating shaft 77 and wl Lh, through an appropriate adjusting screw, abuttingly es with the stationary stop member 82 so as to allow the proper slight working clearance, with valves closed, between the valve tappet cranks 78 and the ends of valve spindles 79.

Clockwise rotation of valve operating shaft 77 as viewed in Fig. l is imparted through crank arm 33 and connecting rod 84 from the bell crank 85 which constitutes a member of a latchable valve operating linkage and is pivoted at 86 to the associated fixed structure. it will be understood that clockwise rotation of crank 85 results in releasing simultaneous blasts in the three phases when the main operating shaft 52 is rotated counterclockwise during an opening or tripping operation of the breaker. The details of the abovementioned blast valve latchable operating linkage are best shown in Fig. 3. As there shown, a cam-like member 66 is affixed to the main operating shaft 52, this member com prising a cam surface 60a and a driving abutment 87 which is adapted to engage a corresponding abutment 38 projecting from a pivoted latch member 89. This latch is mounted between the spaced arms of a carrier memher 9?; which can swing with a parallel motion with respect to the fixed supporting bracket 91 by virtue of the guide links 92 which parallel the lower portion of the bell crank 35. Bracket 91 comprises an appropriately shaped plate which may be welded to the tank side adjacent the tank supporting frame 27, as indicated in Fig. 2, and altords support for the fixed pivots 93 and 94 for the operating linkage. The latch 39 is resiliently coupled to the bridging portion 95 of the carrier l by virtue of the tie bolt 96 passing through the latchs extension ?7; the compression spring 98 biasing the latch 52 and carrier 99 apart to the limit determined by the bolt 96. This limit is such that, when the mechanism 13 is tripped to open the breaker with the consequent counterclockwise rotation of the main shaft 52, the cam abutment 87 will immediately engage the latch abutment 3%, thereby driving the parallel linkage generally downward about the fixed pivots 93 and 94. This downward drive upon the linkage causes clockwise rotation of the crank 85 which results in clockwise rotation of the valve operating shaft 77 which in turn results in simultaneous opening of the three blast valves. Continued rotation of cam member 64) causes its abutment 87 automatically to ride oif the abutment 38 so that the parallel linkage is unlatched, reverses its motion, and resets to its initial position under the action of the valve springs so that the blast valves reclose prior to the termination of the breaker opening stroke.

Conversely, closing of the breaker by means of solenoid as and its armature 37 produces clockwise rotation of the main-shaft 52 and of the cam-like member 6! whereupon the cam surface dda encounters the latch abutment Since the latch 39 is yieldably mounted relative to the carrier Ml, it is merely momentarily depressed by cam surface pile and finally, due to the spring 98, reassurnes its initial latching relationship with respect to the cam 65 i. e., as indicated in Pig. 3 with a slight clearance distance existing between the latching abutments S8 and 87.

it will be observed that the bearings 99 for the main operating shaft 52, and the bearings idd for the valve operating shaft '77, are mounted on and securely bolted to the peripheral flanges 32 of the pair of supporting frames 27 and 2 3 which, as already pointed out, are rigidly mounted upon the basic frame structure of the apparatus.

Because the air tank 12 is connected to and supported from these frames only through the semi-rigid curved lugs 31, it follows that any breathing of the tank, or slight distortion thereof due to varying or transitory pressure differences, is not communicated to these bearings such as might impair the mechanical efiiciency of the breaker moving parts.

While We have described a particular embodiment of our invention, we do not wish to be limited thereto and intend in the appended claims to cover all such changes and modifications as fall Within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric circuit breaker comprising support structure including a pair of rigidly mounted frames disposed in spaced substantially parallel relationship, each of said frames having an opening therethrough, the openings being aligned with each other, a plurality of interrupting units mounted from said structure, each of said units including a pair of separable contacts, an air receiver disposed within said openings and having clearance space relative thereto, a plurality of semi-rigid support bracket; afiixed to each of said frames and to said receiver for supporting said receiver in position, a separate conduit leading from said receive to each pair of said contacts, a valve in each of said conduits for controlling the flow of fluid therethrough, a valve operating shaft rotatably mounted on said frames and operably related with all of said valves, and means for imparting rotary motion to said valve operating shaft to cause operation of said valves.

2. An electric circuit breaker comprising support structure including a pair of frames disposed in spaced substantially parallel relationship, each of said frames having an opening therethrough, the openngs being aligned with each other, a plurality of interrupting units mounted on said structure, an air receiver disposed Within said lurality of semi-rigi support brackets attuned to eac of said frames, said brackets being arranged in pa' 3 with the brackets of each pair secured to said receiver at diametrically disposed positions thereon for supporting said receiver in position, a separate conduit leading from said receiver to each of said interrrupt 1g units, a valve in each of said conduits for controlling the flow of fluid therethrough, a valve operating shaft rotatably mounted on said frames and operably related with all of said valves, and means for imparting rotary motion to said valve o crating shaft to cause operation of said valves.

3. An electric circuit breaker comprising support structure including a pair of frames disposed in spaced substantially parallel relationship, each of said frames having on opening therethrough, the openings being aligned with each other, a plurality of interrupting units mounton said structure, each of said units including a pair separable contacts, an air receiver disposed within s .id openings, a plurality of semi-rigid support brackets attired to each of said frames, said brackets being arranged in pairs with the brackets of each pair secured to said receiver at diametrically disposed positions thereon for supporting said receiver in position, a separate conduit leading from said receiver to each pair of said contacts, a valve in each of said conduits for controlling the flow of fluid therethrough, a valve operating shaft rotatably mounted on said frames and operably related with all of said valves, a main operating shaft :1 on said frames, said main shaft being operably ed with said contacts and with said valve operating shaft, and means mounted on said support structure for imparting operating motion to said main operating shaft.

4. An electric circuit breaker comprising support structure including a pair of frames disposed in spaced substantially parallel relationship, each of said frames having an opening therethrough, the openings being aligned with each other, a plurality of interrupting units mounted on said structure, each of said units including a pair of separable contacts, an air receiver disposed within said openings, a plurality of semi-rigid support brackets affixcd to each of said frames, said brackets being arranged in pairs with the brackets of each pair secured to said receiver at diametrically disposed positions thereon for supporting said receiver in position, a separate conduit leading from said receiver to each pair of said contacts, a valve in each of said conduits for controlling the fiow of fluid therethrough, a rotatable operating shaft mounted on said frames and operably related with each of said valves and pairs of contacts, and means for imparting rotary motion to said operating shaft to cause operation of said valves and contacts.

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References in the tile of this patent UNETED STATES PATENTS 2,232,154 Bakken May 5, 1942 2,342,809 Ludwig et al. Feb. 29, 1944 2,444,765 Boisseau et a1. luly 6, 1948 2,473,892 Ludwig et al. June 21, 1949

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