US3038052A - Circuit interrupting device - Google Patents

Description

June 5, 1962 o. FROLAND CIRCUIT INTERRUPTING DEVICE Filed July 15,' 1960 5 Sheets-Sheet l IBY `lune 5, 1962 Filed July l5, 1960 O. FROLAND CIRCUIT INTERRUPTING DEVICE 5 Sheetsj-Sheet .2

INVENTOR. 514;/ 5mm/a BY M UM ,/frai/VIX June 5, 1962 o. FROLAND CIRCUIT INTERRUPTINC DEVICE 5 Sheets-Sheet 3 Filed July 13, 1960 HW i@ INVENTOR.

dmv Qa/wa 'BY ,/rfllA/fn United States Patent O 3,038,052 CIRCUIT INTERRUPTING DEVICE Olav Froland, Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee, Wis., a corporation of Delaware Filed July 13, 1960, Ser. No. 42,702 8 Claims. (Cl. 200-146) This invention relates to circuit interrupting devices and, more particularly, to load break disconnecting switches.

Load break disconnecting switches generally comprise a disconnect switch Ihaving a circuit interrupter in elec* trical parallelism with its main disconnect contacts and which is adapted to interrupt the circuit after the main switch has been opened. This eliminates the tendency Afor an arc to be struck between the stationary contact jaw and the movable switch blade, should the switch be opened under load. The circuit interrupter usually cornprises fixed and movable contacts disposed in arc extinguishing structure and means for separating said contacts after the disconnect switch has been opened.

XIt is an object of the invention to provide a load break disconnect switch which cannot be accidentally or inadvertently opened without moving its operating lever from one extreme position to another.

Another object of the invention is to provide a load break disconnect switch wherein the circuit interrupter cannot be reclosed until after the main switch contacts are closed so that said circuit interrupter is not required to carry heavy inrush currents.

A further object of the invention is to provide a disconnect switch of the type in which the switch blade is adapted to swing into and out of cooperating relation with stationary contacts and to be rotated about its longitudinal axis to bring oppositely disposed contact surfaces into and out of high pressure engagement with stationary contacts wherein swinging movement is prevented during a switch opening oper-ation, until the desired degree of rotation has been attained. A still further object is to provide such ldisconnect switches with means for preventing rotation of the switch blade during a closing operation until the desired degree of swinging movement toward closed position has been achieved.

These and other objects and advantages of the invention will become more apparent from the detailed description of the invention taken with the accompanying drawings in which:

FIG. l is a side elevational View, with parts broken away, of `the load break disconnecting switch accor-ding to the instant invention in its closed position;

FIG. 2 is a top plan view, partly in section, of the load break disconnect switch shown in FIG. l;

FIG. 3 is a rear elevational view of the preferred embodiment of the invention;

lFIG. 4 is a view taken along lines 4--4 of FIG. 3, with parts broken away;

FIG. 5 is a perspective view of a portion of 4the device; and

fFIG. 6 is a side elevational view of the device with its main contacts and interrupting contacts open.

, Referring to FIGS. 1 and 2 in particular, the preferred embodiment of the invention is shown to include an air 3,038,052 Patented June 5, 1962 ice disconnect switch designated geenrally by the reference numeral 10 and a load interrupting device 11. The disconnect switch 10 includes a switch blade 12 rotatably mounted in a blade guide assembly 14 which, in turn, is pivotally mounted between a pair of frame members 15 secured to a conductive base plate 16 which is aixed to the upper end of a rst porcelain bushing 17. A stationary contact jaw 18 is mounted atop a second porcelain bushing 20 and is engageable by the iiattened, beaver-tal contact portion 22 of switch blade 12 when the latter is moved into its closed position.

The blade guide assembly 14 includes a bearing sleeve 24 in which switch blade 12 is journalled for rotation `and which is in turn pivotally mounted on frame members 15 by a U-shaped bracket 25 and hinge pins 26. An inverted Ushaped operating handle 27 is provided with `a pull ring 30 and a pair of depending legs 28 which are pivotally mounted at their lower ends to the sides of bearing sleeve 24. A collar 34 is suitably aixed to switch blade 10 at a point adjacent the right hand end of bearing sleeve 24, as viewed in FIG. l, and has a pair of integral, parallel, spaced-apart driving arms 35 and 36 which extend downwardly at an oblique angle and which embrace an operating arm 38 extending integrally from the `frontmost leg 28 of operating handle 27. It can be seen that the pivoting of the operating handle 27 in a counterclockwise direction from its position shown by full lines in FIG. 1 to its phantom position will cause operating ar-m 38 to engage the upper driving arm 36 and thereby force the switch blade 12 to rotate in bearing sleeve 24.

The stationary contact jaw 18 comprises two pairs of parallel contact lingers y40 axed at their lower ends to a conductive base plate 42 which is secured to the upper end of bushing 20. In addition, a second contact jaw 44 is provided at the hinged end of switch blade 12 and comprises pairs of parallel contact lingers 46 which are affixed at their lower ends to conductive base plate 16. The current path through the disconnect switch is, therefore, from conductive base plate 42, through contact jaw 18, switch blade 12, contact jaw y44 land conductive base plate 16. It will be appreciated by those skilled in the art that base plates 42 and 16 are each provided with terminal clamps (not shown) suitable for connection to line conductors (not shown). Switch blade 12 also carries a movable auxiliary contact 50 which cooperatively engages a pair of parallel, vertically disposed, stationary, auxiliary contacts 52 which are axed at their lower ends to conductive base plate 42.

Switch blade 12 is supported in its closed position by a bracket 53 extending intgerally upward from base plate 42. In addition, a Y-shaped guide bracket 54 is secured to the base plate 16 and has a pair of guide arms 55 and 56' which engage the underside of switch blade 12 on the opposite sides of its pivotal axis.

When the switch blade 12 is in its closed position as shown in FIGS. 1 and 2 the beaver-tailed contact portion 22 will be lying in a substantially horizontal plane so that its edges will .be in high pressure engagement with the contact lingers 40. As a result of the engagement between switch blade 12 and guide arm 55, pivotal movement of the former in a counterclockwise direction, as viewed in FIG. 1, is prevented when contact portion 22 is in this position. It will be recalled however that when operating -handle 27 is moved from its full to its phantom position in FIG. l, operating arm 38 will engage the upper driving arm 36 to rotate the contact portion 22 of switch blade 12 into an oblique plane so that its edges are out of engagement with the contact lingers '401. This position of switch blade 12 is shown by the full lines in FIG. 5.

'In order to allow pivotal movement of the switch blade 12 after the rotation of contact portion 22 out of its engaged position, a rectangular slot 58 is formed at the hinged end of switch blade 12 and extends diametrically across and through its opposite sides. When the contact portion 22 is in its unrotated position, as seen in FIGS. l and 3, the slot 58 lies in a plane extending generally laterally of the rear guide arm 55. However, rotation of switch blade 12 in the manner described above moves slot 58 into registry with arm 55 as shown in FIG. 5, whereupon the switch blade will be free for pivotal movement to its position shown in FIG. 6 upon the exertion of further force upon operating handle 27. It can be seen, too, that because slot 58 slides over arm 55 when switch blade 12 is pivoted, contact portion 22 is maintained in its rotated position until the switch blade 12 is returned to its initial or unpivoted position between contact fingers 40.

The circuit interrupter 11 is located adjacent the disconnect switch and includes a tubular housing `60 having st-ationary contacts 62 disposed near its contact jaw end and a movable contact rod `64 coaxially disposed for longitudinal movement relative to said stationary contacts. The outer shell of tubular housing 60 is composed of any suitable insulating material such as Bakelite and its interior comprises a plurality of annular rings 66 composed of an arcquenching-gas evolving material such as fibre. A conductive end cap 68 is secured to the contact jaw end of tube I60 and carries the lstationary contacts 62 on its inner surface and an auxiliary contact rod 70 coaxially axed to its outer surface.

A metallic mounting frame 72 threadably receives the other end of tubular housing 60 for supporting it adjacent switch blade 12 and includes a body portion 74 and a pair of integral, septagonally shaped support plates 76, one of which is afxed to the U-shaped bracket 25 of disconnect switch 10. lIn this manner, the switch blade 12 and the circuit interrupter 11 are rigidly affixed for unitary pivotal movement as the disconnect switch 10 is opened and closed.

As seen in FIGS. 2, 3 and 4r, the outer end of the movable contact rod 64 threadably engages an H-shaped operating block 78 which is slidably mounted between support plates 76 by means of a pair of parallel rails 80 affixed to the inner side of each of Vsupport plates 76 and which are disposed :between and for sliding engagement by the upper and lower arms of 82 and 83, respectively, of guide block `78. A pair of apertured ears 84 extend laterally from each side of guide block 78 and between arms S2 and 83 for receiving one end of a pair of opening springs 86 whose other ends are axed to a cross rod 87 extending between support plates 76 near its left hand end as viewed in FIG. 2. It will be apparent that springs 86 urge guide block 78 and contact rod 64 toward the left and their open positions. Referring specifically to FIGS. l and 4, this movement of operating block 78 and contact rod 64 toward their open positions is normally prevented by a latch 88 which is pivotally mounted on one of the side plates 76 by a pin 89 and which is urged toward engagement with operating block 78 by a torsion spring 90.

The current path through the circuit interrupter 11 provides a parallel circuit around the disconnect switch 10 and is from the conductive base plate 42; through the pair of parallel, vvertically extending, auxiliary contact rods 91; by-pass rod 70; conductive end cap `68; stationary contact 62; movable contact rod 64; current interchange springs 97 disposed in annular recess 94 which surrounds contact rod 64; metallic mounting frame 72; and through the lframe members 15 to the conductive base plate 16.

It will be recalled that when operating handle 27 is pivoted from its full position to its phantom position in FIG. l, switch blade 12 is rotated so that slot 58 is in registry with the guide arm of stop member '54 and also the contact portion 22 of switch blade 12 is rotated out of high pressure engagement with the contact lingers 40. As seen in FIG. 4, a resetting arm 96 is pivotally mounted between the upper corners of plates 76 and is connected by a link 98 to the operating handle 27 When operating handle 27 is in its unpivoted position shown by full lines in FIG. 4 a roller 99 carried by the lower end of resetting arm 96 engages the rear of operating block 78. Pivotal movement of operating handle 27 in the manner above described moves resetting arm 96 to its phantom position in FIG. 4 through the agency of link 98. It will also be recalled that when operating handle 27 is in this rotated position slot 58 will be in registry with stop member 55 so that switch blade 12 will be free for rotation away from contact fingers 40. As the switch blade 12 is pivoted away from contact fingers 40, torsion spring 90 will hold the tip of latch 88 in engagement with the operating block 78 so that the circuit interrupter contacts remain closed. Thestationary auxiliary contacts 91 of circuit interrupter 11 are longer than the auxiliary contact 52 of disconnect switch 10 so that after the switch blade 12 and the circuit interrupter 11 have pivoted to a point where the contact rod 50 has moved out of engagement with the contacts 52, the contact rod will still be in engagement with the contacts 91 so Ithat the auxiliary current path through the circuit interrupter 11 remains intact. Upon continued pivoted movement, however, a trip arm 100 extending transversely from latch member 88 will engage the hooked head 101 of 4a trip member 102 pivotally mounted by pin 104 to the frame member 1S adjacent circuit interrupter 11. This engagement will momentarily arrest further rotation of latch member 88. As a result, further pivotal movement of the assembly will move operating block 78 out of engagement with latch 88 so that it will be free for movement toward its open position until it is arrested by stop members 106 affixed to the ends of guide rails 80. Thus, contact rod 64 will be moved out of engagement with stationary contact 62 so that the circuit through interrupter 11 will be opened. Further pivotal movement of switch blade 12 will then move Contact rod 70 out of engagement with the stationary contacts 91.

This continued pivotal movement of switch blade 12 will also cause torsion spring to overcome leaf spring 103 which engages the other end of trip member 102'. As a result, trip member 102 is forced to move from its full to its phantom position in FIG. 6 whereupon latch member 88 will be free to return to its unpivoted position under the inuence of torsion spring 90.

When it is desired to reclose the device, switch arm 12 is pivoted to a point wherein contact rod 50 engages the stationary auxiliary contacts 52 thereby re-establishing the circuit through disconnect switch `10. Although contact rod 70 will have engaged stationary contacts 91, no current will ilow through interrupter 11 because contact rod 64 is still in its open position. Movement of switch blade 12 will continue until `stop 53 is engaged. Upon this event, the operating handle 27, reset arm 96, link 98 and operating block 78 will be in their phantom position shown in FIG. 4. Pivotal movement of operating handle 27 Ifrom its phantom to its full position in FIG. 4 will pivot reset larm 96 in a clockwise direction whereby the engagement of roller 99 with operating block 78 will move the latter toward the left until it is returned to its closed position whereupon it will be re-engaged by latch 88. In this manner the circuit interrupter 11 is reset.

It can be seen, therefore, that the return of operating handle 27 to its original position resets Ithe circuit interrunter 11 as well as forces beaver-tail contact portion 22 of switch blade 12 into high pressure engagement with the contact fingers 40.

While only a single embodiment of the invention is shown and described, other embodiments and modifications will become apparent to those skilled in the art once the inventive concept is known. It is intended, therefore, to cover in the appended claims all embodiments that fall within the true spirit tof the invention.v

I claim:

1. A disconnect switch including stationary contact means and switch blade means rotatable about a longitudinal axis between first -and second angular positions and pivotal about an axis lying in a plane substantially normal to said longitudinal axis, means for rotating said switch blade means between'its first and second angular positions, first stop means mounted on said switch blade, second stop means lying in an interfering relation relative to said first stop means when said switch blade means is in its first angular position to prevent pivotal movement thereof, rotation of said switch blade means to its second angular position being operative to move said first stop means out of an interfering relation relative to said second stop means so that switch blade means lmay be pivoted.

2. A disconnect switch including stationary contact means and switch blade means rotatable about a longitudinal axis between first and second angular positions and pivotal about an -axis lying in a plane substantially normal to said longitudinal axis, stop means lying in the `pivotal path of a portion of said switch blade means when said switch blade means is in its rst angular position whereby pivotal movement thereof is prevented, means 'for rotating said switch blade to its second angular position to move said portion to a position wherein it has an engagement free path relative to said stop means upon pivotal movement of said switch Iblade means.

3. A disconnect switch including stationary contact means and switch blade means rotatable about a longitudinal axis between first and second angular positions and pivotal about an axis lying in a plane substantially normal to said longitudinal axis, stop means lying in the pivotal path of a portion of said switch blade means when said switch blade means is in its first `angular position whereby pivotal movement thereof is prevented, means for rotating said switch blade to its second angular position, recess means formed in said switch blade means and movable into registry with said stop means upon the rotation of said switch blade means to its second angular position so that said switch blade is free for pivotal movement.

4. A disconnect switch including first and second spaced apart bushings, a stationary contact jaw mounted on said first bushing, a switch blade mounted on said second bushing `for rotation about a longitudinal axis and between first and second angular positions and yfor pivotal movement about an axis lying in a plane substantially normal to said longitudinal axis, stop means mounted on said second bushing adjacent said switch blade and in the path of its pivotal movement, whereby pivotal movement of said switch blade is prevented when it is in its ffirst angular position, means `for rotating said switch blade to its second angular position, recess means formed in said switch blade means and movable into registry with said stop means upon rotation of said switch blade to its second angular position so that said switch blade is tree for pivotal movement wherein said slot passes over said stop means.

5. A disconnect switch including first and second spaced apart insulating bushings, a stationary contact jaw mounted on said first bushing, a switch blade mounted on said second bushing for rotation about a longitudinal axis and between first and second angular positions and for pivotal movement about an axis lying in a plane substantially normal to said longitudinal axis, said switch blade having contact means on one end which is in high pressure engagement with said contact jaw when said switch blade is in its first angular position and which moves out of said high pressure engagement when said switch blade is rotated to its second angular positon, stop means mounted on said second bushing adjacent a portion of said switch blade and in the path of said pivotal movement, whereby pivotal movement of said switch blade is prevented when it is in its first angular position, means for rotating said switch blade to its second angular position, a slot yformed in said portion of the switch blade means and movable into registry with said sto-p means upon rot-ation of said switch blade to its second angular position so that said switch blade is free for pivotal movement wherein said slot passes over said stop means.

6. A disconnect switch including first and second spaced apart bushings, a stationary contact jaw mounted on said first bushing, a switch blade mounted on said second bushing for rotation about a longitudinal axis and between first and second angular positions and for pivotal movement about an axis lying in a plane substantially normal to said longitudinal axis, said switch blade having contact means on one end which is in high pressure engagement with said contact jaw when said switch blade is in its first angular position and which moves out of said high pressure engagement when said switch blade is rotated to its second angular position, stop means mounted on said second bushing below said switch blade and adjacent its other end, said stop means extending toward said switch blade and positioned to be engaged thereby upon pivotal movement, whereby pivotal movement of said switch blade is prevented when it is in its iirst angular position, means for rotating said switch blade to its second angular position, a slot formed in said switch blade means on its other end and extending in a generally lateral direction relative to said stop means when said switch blade is in its first angular position, said slot being movable into registry with said stop means upon rotation of said switch blade to its second angular position so that said switch blade is free for pivotal movement wherein said slot passes over said stop means.

7. The combination of a disconnect switch and a load interrupter, said disconnect switch including stationary contact means and switch blade means rotatable about a longitudinal axis between first and second angular positions and pivotal about an axis lying in a plane substantially normal to said longitudinal axis and into and out of engagement with said stationary contact means, interference means for preventing pivotal movement of said switch blade when it is in its first angular position, said interference means being inoperative to prevent such pivotal movement when said switch blade is in its second angula-r position, operating means for rotating said switch blade means into its second angular position, said load interrupter including fixed and movable contact means, latch means for holding said circuit interrupter in closed position, trip means operable after said switch blade means has pvoted out of engagement with said stationary contact means to release said movable contact means, a reset arm pivotally mounted on said switch blade means and connected to said operating means for moving said movable contact into its latched position when said switch blade is rotated into its first angular position and movable away from said movable contact means when said switch blade is rotated to its second angular position.

8. The combination of a disconnect switch and a load interrupter, said disconnect switch including stationary contact means and switch blade means rotatable about a longitudinal axis between first and second angular' positions and pivotal about an axis lying in a plane substantially normal to said longitudinal axis and into and out of engagement with said stationary contact means, stop means lying in the pivotal path of a portion of said switch blade means when the same is in its first angular position whereby pivotal movement thereof is prevented, operating means for rotating said switch blade means into its sec- V ond angular position, recess means formed in said switch 6 blade means and movable into registry With said stop means upon the rotation of said switch blade means to its second angular position to allow pivotal movement thereof, said load interrupter including fixed and movable Contact means, latch means for holding said circuit interrupter in closed position, trip means operable after said switch blade means has pivoted out of engagement with said stationary contact means to release said movable contact means, a reset arm pivotally mounted on said switch blade means and connected to said operating means for moving said movable contact into its latched position S when said switch blade is rotated into its rst angular position and movable away from said movable contact means when said switch blade is rotated to its second angular position.

References Cited in the file of this patent UNITED STATES PATENTS 1,807,030 Edmonds May 26, 19,31 2,249,662 Matthews July 15, 1941 2,575,707 Gilliland et al Nov. 20, 1951 2,676,216 Zeth Apr. 20, 1954

Images