US2897323A - Switch means - Google Patents

Description

July 28, 1959 F. J. KRASE ETAL SWITCH MEANS Filed May 22. 1958 United States Patent Ofitice 2,897,323 Patented July 28, 1959 SWITCH MEANS Fred John Krase and Edward K. Olendzki, Chicago, 111

assignors to H. K. Porter Company (Delaware), Chrcago, Ill., a corporation of Delaware Application May 22, 1958, Serial No. 737,168

7 Claims. (Cl. 200-146) The present invention relates to high tension electric switch gear, and particularly, to improvements in switch assemblies of the type comprising a disconnect switch and an interrupter switch associated with the disconnect switch for actuation by the blade thereof. The invention constitutes, especially, an improvement on the disclosure of the co-pending application of Nicholas Polgov and Glen R. Runke, Serial No. 679,201, filed August 20, 1957.

In the said co-pending application of Polgov and Runke, there is disclosed a high tension switch assembly including a disconnecting switch having a switch blade that is adapted to be swung in an are for movement into and out of the stationary contact of the switch and that is also rotatable about its own axis to eifect high pressure engagement with the contact. Mounted adjacent the stationary contact of the disconnecting switch is an interrupting switch having an actuator arm disposed in the path of arcuate movement of the disconnecting switch blade for effecting actuation of the interrupter as a consequence of and in predetermined relation to the switch opening and closing movements of the disconnecting switch blade. Such assembly is highly advantageous in that it positively assures interruption of current flow and closing of the circuit without the occurrence of external arcing.

However, the described assembly sufiers the disadvantage that some external sparking occurs between the disconnect switch blade and the actuator arm of the interrupter due to the difiiculty of maintaining continuous commutation between these two relatively rotating parts. Such external sparking, while not critical in an electrical sense, is objectionable and detracts from the otherwise exemplary functioning of the switch assembly.

The object of the present invention is to provide means for mitigating external arcing or sparking in switch gear of the character described.

More particular, it is an object of the present invention to provide means interposed between the disconnect switch blade and the arm of the interrupter which affords continuous commutation between relatively rotatable parts and eliminates external sparking.

Another object of the invention is the provision of means of the character described in the form of improved arcing horn means for the disconnect switch.

A further object of the invention is the provision, in the assembly of an interrupter switch and a disconnect switch, of a non-rotatable arcing horn for the disconnect switch blade, said horn engaging but having no rotary movement relative to the actuator of the interrupter switch to mitigate sparking therebetween, and having a journal connection with the disconnect switch blade affording continuous commutation between the two to mitigate sparking therebetween.

A still further object of the invention is the provision of an improved arcing horn for the stationary contact of the disconnect switch and improved means on the actuator of the interrupter switch cooperable with the areing horn on the disconnect switch blade for positively retaining the same against rotary movement, thereby further to insure against the occurrence of external sparkmg.

Other objects and advantages of the present invention will become apparent in the following detailed description of a preferred embodiment of the invention.

Now, in order to acquaint those skilled in the art with the manner of making and using our improved anti-sparking means, we shall describe, in connection with the accompanying drawings, a preferred embodiment of our invention and a preferred manner of making and using the same.

In the drawings:

Figure 1 is a side elevation of a switch assembly comprised of a disconnecting switch and an interrupting switch equipped with the improved anti-spark horn means of our invention, the assembly being illustrated in its closed position in solid lines and in several positions of movement in dotted lines;

Figure 2 is an end elevation of the switch assembly, the view being taken from the right-hand end of Figure 1;

Figure 3 is a fragmentary view, on an enlarged scale of the improved arcing horn means provided according to our invention on the disconnect switch blade;

Figure 4 is a fragmentary view illustrating a modified manner of mounting the horn on the blade;

Figure 5 is an end elevation of the improved arcing horn means provided according to our invention on the stationary contact of the disconnect switch; and

Figure 6 is a cross-sectional View of the improved contact assembly provided according to our invention on the actuator arm of the interrupter.

With reference to Figures 1 and 2, we have illustrated :a switch assembly comprised of a disconnecting switch D and an interrupting switch I. The disconnect switch D is of the type shown and described in the patent to Fjellstedt et al. No. 2,527,924. The switch comprises, generally, a base (not shown) carrying three insulators 12, 14 and 16, the outboard ones of which are stationary and carry terminal lugs 18 and 20 and the center one of which is rotatable. The right-hand insulator 12 carries the stationary contact 22 of the switch and the left-hand insulator carries the frame 24 of the switch operating mechanism. This mechanism includes a blade guide or supporting part 26 pivotally mounted on the frame 24, a blade carriage 28 rotatable in the guide, and a crank arm 30 secured to the upper end of the rotatable insulator 14, the arm 30 and carriage 28 being rotatably connected at 32 along an axis extending at an angle of approximately 45 to the axis of the insulator 14. The switch blade, which is indicated :at 34, is secured adjacent one end in the carriage 28 and extends therefrom to the stationary contact 22, the blade at its outer end being flattened in the form of a beaver tail for purposes of high pressure engagement in the contact. As is conventional, the blade 34 and the contact 22 carry cooperable arcing horns 36 and 38, respectively. However, the particular form of these horns, as illustrated and later described, forms part of the present invention.

To eifect operation of the disconnect switch, the insulator 14 is rotated about its own axis to impart movement to the switch blade 34. Upon initial rotation of the insulator the blade 34 is subjected primarily to rotation around its own axis to relieve its high pressure engagement in the contact 22, whereafter the blade, while continuing to rotate, is swung in an arc of approximately about the pivot axis of the guide or supporting part 26 to a substantially vertical switch open position. During such movement, the insulator 14 is rotated in an are somewhat greater than 90 and the blade is both rotated about its own axis 90 and swung in an arc of approximately 90. Upon reverse rotation of the insulator, the blade is returned to its switch closed position in reverse order.

The interrupt-er .I is disclosed in detail in the aforesaid co-pending application of P-olgov and Runke. Generally, it comprises a column mounted in an upright position on the stationary contact of the disconnecting switch, the column forming an interrupting chamber and adjacent its upper end including an actuating mechanism having an external oscillatable actuator arm 40 adapted to be engaged-and moved in response to movement of the blade 34 of the disconnect switch whereby interruption of current flow and disconnection of the circuit may be effected simply by operating the disconnect switch. In particular, as shown in Figure 1, the path 'of arcuate movement of the blade arcing horn 36 intersects at .two points the path of oscillation of the free end of the arm 40. During opening movement of the switch blade 34, the horn 36 engages the arm 40 whereupon the circuit normally completed through the blade 34 and contact 22 is completed from the blade through the interrupter to the terminal 18. As movement of the blade toward its open position continues, the actuator arm 40 is rotated in the upward direction until the blade 34 is sufliciently separated from the contact 22 to prevent striking of an arc therebetween. At approximately this point, the interrupter is actuated to break the circuit. Thereafter, -due to the differences in length and relative location of the pivot axes of the blade 34 and arm 40, the actuator arm 40 is released from the born 36 as the blade 34 continues to move toward full open position. The arm 40 is then returned automatically to a predetermined position in the arcuate path of movement of the horn 36.

To reclcse the circuit, the disconnect switch is operated to move the blade 34 toward closed position. During closing movement, the horn 36 on the blade again engages the actuator arm 40 of the interrupter to move the same downwardly. As the blade 34 approaches the contact 22, the interrupter is actuated to remake the previously described circuit. The born 36 remains in contact with the actuator arm 40 until the horn 38 is reengaged, whereafter the arm '40 maybe released for automatic return to the position shown in Figure 1, the circuit then being completed directly through the blade 34 and contact 22.

As will be appreciated from the above brief description, the construction and cooperation of the two switches D and I is such that no external arcing'is intended to occur upon either opening or closing of the switches. It is intended that such arcing as may occur will take place within the interior of the interrupting chamber of the switch 1. However, it has been found that whena conventional arcing horn is provided on the disconnect switch blade 34, the relative rotation between the horn and the arm 40 of the interrupter results in the occurrence of external sparking, which is objectionable.

To overcome this disadvantage, 'we provide improved means, preferably in the form of improved arcing horns for the disconnect switch and an improved contact assembly for the arm 40 of the interrupter, which mitigate against and etfectively eliminate external sparking or arcing in switch assemblies of the character illustrated.

In particular, we provide an improved arcing horn 36 for the 'disconnectingswitch blade .34 comprising an elongate conductive rod having a body portion '52 generally parallleling the switch blade 34 and an end portion 54 projecting beyond the .end of the blade 34. At its inner end, the body portion "52 of the rod is fixedly attached, as by nuts 56, tothe non-rotatable but arcuately movable supporting ,part or guide-26 for theswitch blade, whereby the rod is held against rotation yet is =arcuately movable with the :blade. The outer :end ,portion 54 of the "rod is preferably of generally rectangular configuration and includes a pair of parts or sides 58 and 60 paralleling the blade 34 and spaced respectively above and below the axis of the blade. The two parts or sides 58 and 60 are joined at their outer ends by a transverse part 62, and the terminal portion of the rod is bent into axial alignment with and extends toward the outer end of the blade 34. At its outer .end, as shown in Figure 3, the blade 34 .is provided with a pair of brackets 64 including spaced portions extending transversely of the blade between which a bearing 66 is fixedly mounted, the axis of the bearing coinciding with the axis of the blade. The bearing '66 receives for relative rotation therein the terminal end of the horn-forming rod, thereby to support the rod, electrically connect the rod to the blade, and effectively journal the same on the blade. Alternatively, the bearing 66 could be disposed within the blade and the terminal end of the rod could be extended through the beaver tail end portion of the blade and journalled in the bearing as illustrated in Figure 4.

By virtue of its mounting, the improved blade arcing horn of our invention will mitigate external sparking at or adjacent the blade, since its point or points of current exchange with the blade are within the interior of the bearing 66 and within the interior of the supporting part 26, both of which provide bearing surfaces affording good commutation between the respective pairs of relatively rotatable parts. Moreover, the horn is held against rotation 'by the supporting part 26 and is therefore adapted to engage the actuator arm 40 of the interrupter I without occurrence of appreciable relative rotation therebetween, whereby our improved arcing horn also mitigates external sparking at this point of current exchange. Accordingly, the blade horn alone may suflice in many instances to prevent external arcing or sparking.

However, there must of necessity be sliding engagement between the blade born 36 and the contact horn 38 and between the blade horn and the actuator arm 40 of the interrupter. Also, due to the length of rod necessary to extend to the supporting part or blade guide '26, the blade born 36 will be subject to some side sway, resulting in further relative movement between the blade horn and the elements engaged thereby. These relative movements, while slight, may result in the occurrence of a small degree of sparking.

To afford complete mitigation against external sparking, we provide an improved contact horn 33 and an improved contact-assembly, indicated generally at 7%, on the free end of the actuator arm 40 of the interrupter, which horn and assembly cooperate with the blade horn 36 in such manner as toeliminate entirely the occurrence of external sparking. Also by virtue of these improved means, any disadvantages that would otherwise result from side sway or flexing of the blade born 36 are eliminated, thereby to accommodate formation of our improved blade horn in a highly economical manner from lighter stock than would otherwise be required.

'Our improvedcontact horn 38, as shown in Figures 1, 2 and 5, is preferably comprised of an integral rod of conductive metal bent to a generally U-shape, the bight portion 72 of which is bent into a generally horizontal positionjand clamped by suitable means to the terminal pad -1'8on'whichthejaws of the stationary contact 22 aremounted. The two legs 74 and 76 of the rod are inclined upwardly and outwardly relative to the contact structure to a point beyond the end of the disconnect switch blade '34 and approximately intermediate the length of theend portion 54 of the blade horn 36. These inclined portions 'of the legs 74 and 76 also converge toward the axis of the switch blade, and at the said point merge with vertical portions of the respective legs. The vertical portions of the legs are disposed closely adjacent one another in parallel relation to receive therebetween the parts -or sides 58 and 60 of the end portion 54 of the blade born. The converging portions of the legs 74 and 76 serve as a resilient mounting for the vertical portions of the legs and are so bent that said vertical portions are normally biased to a position in which the spacing therebetween is less than the diameter of the rod forming the blade horn, whereby the contact horn resiliently and frictionally engages the parts 58 and 60 of the blade horn. To facilitate entry of the blade horn between the legs of the contact horn, the upper ends of the legs of the contact horn are flared outwardly, as shown in Figure 5.

In use, the cooperating portions of the two horns mitigate against external sparking upon relative sliding movement thereof and prevent the occurrence of relative rotation therebetween. Specifically, the space between the vertical portions of the contact horn 38 is aligned with the axis of the blade 34. The terminal part of the blade horn 36 is journalled on the axis of the blade 34 and the portions 58 and 60 thereof which engage between the spaced portions of the horn 38 are offset from the said journal axis. Accordingly, the said spaced portions retain the blade horn against rotation, thereby to afiord optimum mitigration against sparking between the two horns.

The contact assembly 70 provided on the interrupter actuating arm 40 similarly provides spaced portions for the frictional and resilient reception therebetween of the parts 58, 6t and 62 of the blade horn 36, thereby to perform the same function as outlined above and mitigate against sparking between the blade horn and the arm 40.

Referring to Figures 2 and 6, the preferred embodiment of the contact assembly 70 is illustrated as comprising a stub shaft 8%) projecting horizontally from the free end of the arm 40, a pair of opposed cup washers or contact bells 82 and 84 slidably mounted on the shaft, a spacing ring 86 between the bells, a pair of springs 88 and 98 on the shaft for biasing the bells 82 and 84 toward one another, and a retaining nut 32 threaded on the free end of the shaft. The spacing ring 86 is of a thickness less than the diameter of the rod forming the blade born 36 and the curvature of the cups or bells 82 and 84 facilitates entry therebetween of the blade born to force the bells apart, the space between the bells being aligned vertically with the space between the legs 74 and 76 of the contact horn and the axis of the blade 34 whereby the bells, in cooperation with the parts 58 and 60 of the blade horn, retain the blade horn against rotation relative thereto,

The remaining feature of our improved means for preventing external sparking in switch gear of the character described :is that the spacing between the parts 58 and 60 of the blade horn 36 is greater than the distance between the spaced portions of the contact horn 38 and the contact assembly 7% when the two switches are in their closed positions, thus to insure a mechanically complete electrically conductive path through the disconnect switch or the two switches at all times prior to interruption of the circuit within the interrupter upon opening of the switches, and at all times subsequent to remaking the circuit within the interrupter upon closing of the switches.

In use of the apparatus illustrated and described, the electric circuit is normally completed through the blade 34 and stationary contact 22 of the disconnecting switch. Upon initial rotation of the insulator 14, high pressure engagement between the blade and contact is relieved. As the beaver tail end of the blade separates from the jaws of the contact 22, the electric circuit is completed through the blade 34 and the horns 36 and 38. During rotary movement of the blade, the horn 36 is retained against rotation by the supporting part or blade guide 26 and by the horn 38. As the blade moves arcuately upward, the part 58 of the horn 36 moves out of the horn 38, and the part 60 remains within the contact horn until the part 58 seats firmly between the contact bells 82 and 84 of the assembly '70. This assembly also holds the born 36 against rotation, thereby to prevent sparking. Subsequently, the horn 36 separates from the horn 38, whereupon the electric circuit is completed through the blade 34, the born 36, the assembly 70, the arm 40 and the interrupter I, without occurrence of any arcing or sparking between the horns 36 and 38. During continued upward movement of the blade 34, the part 58 of the horn 36 swings the arm 40 upwardly until the part 60 of the horn is suficiently separated from the horn 38 to assure that an arc will not strike between the two horns. The interrupter is then actuated to open the circuit, without occurrence of external arcing or sparking, whereafter the parts 58 and 62 of the horn 36 slide through the bells 82 and 34 and release the arm 40 for movement back into the path of arcuate movement of the horn 36, the blade 34 and born 36 continuing their arcuate movement to a substantially vertical, full open position.

Upon closing movement of the switch blade 34, the part 60 of the born 36 is moved into the space between the bells 82 and 84. This occurs without sparking, since the interrupter is then in open circuit position. As the blade 34 continues its downward movement, the bells retain the horn 36 against rotation as the part 60 of the horn swings the arm 40 downwardly to actuate the interrupter, whereupon the circuit is remade within the interior of the interrupter without occurrence of external arcing, the circuit then being completed through the interrupter, the arm 40, the contact assembly 70, the horn 36, and the blade 34. Subsequently, the parts 69 and 62 of the born 36 slide through the bells 82 and 84 until the part 60 re-engages between the legs 74 and 76 of the horn 38, again without sparking, thus to complete the circuit through the disconnect switch blade and the horns. Thereafter, the arm 40 is released for return to its initial position and the blade 34 continues to its fully closed position, the engagement of the horns 36 and 38 preventing the occurrence of external sparking or arcing during this portion of blade movement. Finally, the blade is rotated into high pressure engagement with the contact 22 to complete the circuit closing operation.

Thus, it is apparent that the improved means of the invention affords optimum mitigation of external sparking and appreciably enhances the operation of the switch assembly. The means employed are economical and do not in any way detract from the appearance or functioning of the switches. Accordingly, the objects of the invention have been shown to be attained in a convenient, practical and economical manner.

While we have described what we regard to be the preferred embodiment of our invention, it will be appreciated that various changes, rearrangements and modifications may be made therein, and that less than all of the apparatus of the preferred embodiment of our invention may be satisfactorily employed for the purposes stated, without departing from the scope of the invention as defined by the appended claims.

We claim:

1. In the combination of a disconnect switch having a rotatable and arcuately movable switch blade and an arcuately movable supporting part, and an interrupter switch having an actuator arm actuated in response to arcuate movement of the disconnect switch blade, the improvement comprising interrupter actuating means fixed to the said supporting part and arcuately movable with the blade for non-rotary engagement with the actuator arm of the interrupter switch.

2. In the combination of a disconnect switch having a rotatable and arcuately movable switch blade and an arcuately movable supporting part, and an interrupter switch having an actuator arm actuated in response to arcuate movement of the disconnect switch blade, the improvement comprising an elongate arcing horn for the switch blade, said horn being fixed to said supporting part at one end and being journalled on the outer end portion of said blade at its other end for arcuate movement with the blade and for non-rotary engagement with the actuator arm of the interrupter switch to mitigate external sparking.

3. In a switch assembly comprised of a disconnecting switch having a stationary contact and a rotatable and swingable blade movable into and out of the stationary contact, and an interrupting switch having an actuator to be moved in response to the swinging movement of the disconnecting switch blade, the improvement comprising an arcing horn journalled on the disconnecting switch blade, an arcing horn on the stationary contact of the disconnecting switch, and a contact assembly on the actuator of the interrupting switch, said stationary contact horn and said contact assembly including means for frictionally gripping said blade horn to retain said blade horn against rotation relative thereto, said blade horn actuating the interrupting switch.

4. In a switch assembly comprised of a disconnecting switch having a stationary contact and -a rotatable and swingable blade movable into and out of the stationary contact, and an interrupting switch having an actuator to be moved in response to the swinging movement of the disconnecting switch blade, the improvement comprising an arcing hom journalled on the disconnecting switch blade, an arcing horn on the stationary contact of the disconnecting switch, and a contact assembly on the actuator of the interrupting switch, said stationary contact horn and said contact assembly having spaced portions for frictional reception therebeween of said blade horn to retain said blade horn against rotation relative thereto,

said blade horn actuating the interrupting switch and ineluding a portion extending transversely of said blade 2 cooperable with said spaced portions and of a length greater than that necessary to span the distance between the two sets of said spaced portions in the closed position of the switches.

5. In a switch assembly comprised of a disconnecting switch having a stationary contact and a rotatable and swingable blade movable into and out of the stationary .contact, and an interrupting switch having an actuator to be moved in response to the swinging movement of the disconnecting switch blade, the improvement comprising an arcing horn journalled on the disconnecting switch blade, an arcing horn on the stationary contact of the disconnecting switch, and a contact assembly on the actuator of the interrupting switch, said stationary contact horn and said contact assembly having spaced portions and a swingable supporting part in which the blade is including spaced portions for frictionally receiving said blade horn therebetween, and a contact assembly on the free end of the actuator of the interrupting switch, said assembly including spaced portions aligned with the said spaced portions of said stationary arcing horn for frictionally receiving said blade horn therebetween during opening and closing movements of the disconnecting switch blade, whereby said blade horn has non-rotary engagement with the said actuator to actuate the interrupting switch without occurrence of external sparking.

7. In a switch assembly comprised of a disconnecting switch having a stationary contact, a rotatable and swingable .blade movable into and out of the stationary contact and a swingable supporting part in which the blade is .journalled, and an interrupting switch having an actuator to be moved in response to movement of the disconnecting switch blade, the improvement comprising an elongate arcing horn having a body portion generally paralleling the blade of the disconnecting switch and an end portion of generally rectangular configuration, said horn being fixed to the said supporting part at the inner end of said body portion, said end portion projecting beyond the endof the disconnecting switch blade and being journalled at its terminal end on the outer end portion of the blade coaxially therewith, said end portion including parts spaced from and generally paralleling the disconnecting switch blade above and below the axis thereof, an arcing horn on the stationary contact of the disconnecting switch engaging at least the lower one of said parts of said blade horn in the closed position of the switch, said stationary arcing horn including spaced portions for frictionally receiving the said lower part of said blade horn therebetween, and a contact assembly on the free end of the actuator of the interrupting switch, said assembly including spaced portions aligned with said spaced portions of said stationary arcing horn for frictionally receiving therebetween the upper one of said parts of said blade horn during opening movement of the disconnecting switch blade and for frictionally receiving therebetween the lower one of said parts of said blade horn during closing movement of the disconnecting switch blade, whereby said blade horn has non-rotary engagement with said actuator to actuate the interrupting switch without occurrence of external sparking, the distance between said parts of said blade horn being greater than the distance between said stationary horn and said contact assembly in the closed positions of the switches.

References Cited in the file of this patent UNITED STATES PATENTS 2,697,153 Owens et a1 Dec. 14, 1954

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