US2287499A - Jumpering device - Google Patents

Description

June 23, 1942.

2 Sheets-Sheet 1 S. R. SMITH, JR

JUMPERING DEVICE Filed March 20, 1941 m J m Mm m 53w won/Z v A haw s n m H S Jun '23, 1942. s. R. SMITH. an

JUMPERING DEVICE Filed March 20, 1941 2 Sheets-Sheet 2 Inventor: Sidngeg R Smith Jn,

His Attorney.

Patented June 23, 1942 J UMPERING DEVICE Sidney R. Smith, Jr., Pittsfield, Mass, assignor to General Electric Company, a corporation of New York Application March 20, 19-11, Serial No. 334,375

14 Claims.

The present invention relates to electric circuit interrupting apparatus such as fuse cutouts,

line sectionalizing switches, and the like, and more particularly to improvements in jumpering devices for such apparatus.

A common form of electric circuit interrupting apparatus known as a reclosing cutout consists essentially of an insulating housing having a pair of spaced line terminals and a removable door upon the inner side of which is mounted a pair of fuses. The cutout also includes a mechanism whereby the second fuse is inserted automatically into the circuit following the blowing of the first fuse as upon the occurrence of a temporary fault. It is desirable that the blown fuse be replaced by a new one before another fault results in a service interruption by the blowing of the second fuse. In renewing the blown fuse it is the general practice to make a jumper connection across the line leads whereupon the door of the cutout may be removed without interrupting the load current.

It is an object of the present invention to provide a new and improved maintenance device for effecting a jumper connection across the line terminals of a cut-out or the like apparatus which device is easy and safe to manipulate.

It is a further object of the present invention to provide a jumpering device which is light in weight, comprises a relatively few parts and which may be manufactured at a relatively low cost.

It is a further object of the invention to provide an improved maintenance device which may be employed for servicing sectionalizing switches, reclosing fuse cut-outs and like forms of interrupting devices.

In accordance with one form of the invention an insulating handle is provided with a pair of laterally extending and relatively movable prong contacts. The prong contacts are electrically interconnected and adapted for insertion into suitable openings through a side wall of a switch or cutout casing and into engagement with the line terminals therein. The spacing of the prong contacts is adjusted by meansincluding the handle and in such a manner that the jumper connection is maintained firmly between the line terminals during the servicing operation of the switch device.

Further objects and advantages of the invention will appear from the following description and the claims appended thereto taken in connection with the accompanying drawings.

In the drawings, Fig. 1 is a front elevation partly in section of an electric switch device the line terminals of which are interconnected by a jumpering device constructed in accordance with one form of the present invention; Fig. 2 is an enlarged longitudinal cross-sectional view of the jumpering device shown in Fig. 1; Fig. 3 is a longitudinal cross-sectional view of a jumpering device constructed in accordance with a second modification; Fig. 4 is another sectional view illustrating a still further modification of the invention; Fig. 5 is a view taken on line 5-5 of Fig. 4; and Fig. 6 is a view partly in section showing a particular operating position of the jumpering device of Fig. 4.

Referring to Fig. 1, an electric circuit interrupting device is shown comprising an insulating casing I0 having a pair of space line terminals II and 12 mounted therein and electrically connected to the line leads I 3 and I4, respectively. Normally closing the open front of the casing is a removable door i5 upon the inner side of which is mounted a circuit interruting unit, not shown, for interconnecting the line terminal II and i2 and which, for example, may comprise a pair of fusible elements and an automatic reclosing mechanism.

For bridging the line terminals l i and [2 of the circuit interrupting device so that the cover l5 may be removed for replacement of a blown fuse or other servicing operation without interrupting the circuit, I provide a jumpering device generally indicated at I 6. This device is provided with a pair of electrically interconnected contact prongs which are adapted for insertion into openings l3 and 20, respectively, in a side wall of the cutout casing l0 and for engagement with the adjacent spaced line terminals H and I2, respectively.

In the embodiment of the invention illustrated in Fig. 2, the jumpering device comprises a round, longitudinal handle 25 of a suitable insulating material such as wood, having a pair of spaced, relatively movable metal prong contacts 25 and 21 mounted on one end thereof and extending laterally with respect thereto. One contact 26 is formed integrally with the cylindrical portion 28 of substantially the same diameter as the handle 25, the portion 28 being provided with a ferrule 29 for cooperatively fitting over the reduced end portion 3| of the handle 25 and which is secured thereto by means of a through rivet 32. The upper contact 2'! is formed integrally with a cylindrical portion 33 which is also of substantially the same diameter as the round handle 25 and is arranged within the upper end of the insulating tube 34. The insulating tube 34 may be of any suitable material such as fiber and extends concentrically downwardly over the round handle 25, the inner diameter of the tube being just slightly greater than the outer diameter of the handle 25 50 that the tube 36 may be moved freely longitudinally over the handle. The tube 34 is provided with a longitudinal slot 35 along one side at the upper end thereof of a width substantially equal to the thickness of the prong contacts 255 and 21, and through which the contacts extend and are thereby maintained in an aligned relation.

The contacts 26 and 27 are electrically interconnected such as, for example, by the flexible conductor 31 the opposite ends of which may be soldered or swaged into the sleeve portions 38 and 38 of the contacts 26 and H, respectively. The contacts are biased apart by means of a compression spring 4| arranged within the tube 34 and engaging the facing surfaces of the cylindrical portions 23 and 33 of the two contacts. A stop pin 42' is arranged across the upper end of the tube 34 above the cylindrical portion 33 of the upper contact and suitably secured as by peening over the opposite ends thereof.

A rubber bumper 43 secured in a cooperating hole in the lower contact portion 28 is arranged between the lower end of the slot 35 of tube 34 and the lower contact 26.

The jumpering device described may be operated by holding the handle at an angle with respect to the side of the cutout casing and inserting the upper contact into the upper hole 19 in the cutout casing. Then by pushing up on the lower end of the handle 25, the spacing between the two contacts may be adjusted, the lower contact brought into a position adjacent the lower cutout casing hole and inserted therein. After insertion of the jumper contacts into the openings of the cutout casing and release of the handle 25, the compression spring M will force the contact prongs apart into a wedging engagement with the line contacts and effectively secure the jumpering device in position while the cutout is being serviced. It will be observed that the contact prongs 28 and 21 are angularly disposed with respect to the longitudinal axis of the handle and divergently with respect to each other so that upon insertion of the contacts into the casing openings 19 and 20 of the circuit interrupter, the opposite sloping surfaces of the prongs will engage with the inner corners 14 and 55 of the casing openings so that under the force of the spring 4| the ends of the contact prongs will tend to be forced with a wedging action against the line terminals H and I2 of the circuit interrupter.

In the modification illustrated in Fig. 3, the jumpering device comprises a longitudinal insulating handle 50 upon the upper end of which is mounted the spaced and relatively movable prong contacts 5| and 52 which, as in the previous modification, extend laterally from one side of the handle. The contact 52 is formed integrally with a hollow cylindrical member 53 which extends coaxially from the end of the handle 59. The upper contact 5! is formed integrally with a cylindrical portion 54 which is axially movable within the cylindrical member a longitudinal slot 55 being provided in the upper end of the cylinder 53 through which the contact 5! extends in alignment with the contact 52. The cylindrical portion 5 3 of the upper contact 5| is cooperatively threaded upon the:

screw 53 the opposite end 57 of which is fixedly secured in the upper end of the handle 58 as by means of a through rivet 58. Arranged around the screw 56 and within the cylinder 53 between the lower surface of the upper contact portion 54 and the upper surface of the sleeve 59, which is fixed in the lower end of the cylinder 53 as by pins 69, is a compression spring 6| biasing the contacts 5! and 52 apart and biasing sleeve 53 against the upper end surface of handle 5G. An insulating sleeve 62 is slid over the cylinder 53, having a slot 63 coinciding with the cylinder slot at its upper end and a slit 64 between the lower end and the opening 85 for the contact 52.

In operating this device, the separation of the contacts 5i and 52 is first adjusted to the distance between the openings in the cutout casing by turning the handle 5%] while holding the cylindrical portion 53 stationary as by insertion of the lower prong 52 into the corresponding cutout casing opening. The upper contact prong is then inserted into the upper opening in the side of the cutout casing and the handle 50 is rotated in the proper direction so as to move the contacts 5'! and 52 relatively toward each other. It will be observed that the ends of the contacts are bent toward each other by a slight angle so that when the contacts are moved together, the facing sloping surfaces thereof will engage with the inner edges of the casing openings, to force the ends of the contact prongs with a wedging action against the adjacent surfaces of the line terminals. In this manner not only is a good contact assured between the line terminals but also the jumpering device is securely held in position while the circuit interrupter is being serviced.

In the further modification of the invention illustrated in Figs. 4 to 6, inclusive, a more compact device is provided which has in place of a long operating handle, a relatively small insulating cover by which the device may be operated. In this device, the jumper connection element is also pivotally mounted within the cover so that it may be snapped into the side openings of the cutout box by a pressure exerted laterally of the device. The device is held in place by means of a suitable spring and an over-center arrangement of the pivotal supporting linkage. The insulating cover H may be of any suitable molded insulating material and has an operating handle 12 and an open side is opposite the handle 12. For eifecting a jumper connection between the line terminals H and [2 of the cutout ill, a jumpering element M is arranged within the casing H comprising essentially a pair of contact prongs l5 and 18 having their ends bent towards each other and which are interconnected by a flexible conductor H. The upper prong I5 is formed integrally with a ferrule 78 mounted upon the end of an insulating tube 79. The lower contact prong 16 is formed integrally with a metal sleeve 8i) slidably arranged over the lower end of the tube 19. The upper end of the conductor H is conductively connected to the ferrule 18 in a suitable manner by means of the nut 8!, while the lower end is connected to the metal sleeve 80 by means of the leaf spring clasp 82. The ferrule 78 is provided with a downwardly extending portion 83 the lower end of which is pivotally connected by means of a pair of links 84 to the arms of the U-shaped support 85. The support 85 is in turn secured to the rear wall of the casing H as by a screw 86. Outward movement of the upper end of the jumper element 14' is limited by means of stops 8'! formed on the ends of the support arms and which are adapted to be engaged by the links 84 in the extended position of the jumper element as shown in Fig. 6. The lower end of the jumper element is mounted upon the outer end of a curved blade spring 88, the opposite end of which is secured as by a screw 89 to the rear wall of the insulating casing H. The outer portion of the spring 88 is suitably notched for cooperatively receiving the metal sleeve 88, and the ends of the spring extend through slots formed between pairs of bosses 9| provided on diametrically opposite sides of the sleeve 80. The spring 88 is so shaped that the ends thereof extending through the slots between the bosses 9| bias the jumper element 14 in the clockwise direction with regard to the cover H to an outwardly projecting position as indicated in Fig. 6. In this position of the jumpering element, the contact prongs 15 and 16 spread somewhat farther apart than in the collapsed condition of the device and preferably to the extent that their ends are spaced a distance substantially equal to the spacing between the openings l9 and 2D in the side of the cutout I0. After the ends of the contact prongs l5 and have been inserted through the side openings in the cutout box, the cover H is then pushed toward the cutout box to the position as shown in Fig. 4, by which operation the contact prongs l5 and Hi will be drawn together. In this operation the jumper element 14 will pivot about the end of the spring 88 and the lower pivot of the links 84 will be moved over-center with regard to the upper pivot thereof and the supporting point on the end of the spring 88. This pivoting movement of the device within the cover will be accompanied by a downward movement of the tube 13 within the sleeve 80 against the bias of the blade spring 88 and, hence also, a movement of the contact prongs 15 and 16 toward each other. The inwardly sloping facing surfaces of the ends of the contact prongs will engage with the inner edges of the openings [9 and 20 whereby, as in the preceding modification, the contact prongs will be forced with a wedging action against the line terminals H and I2 of the cutout. Upon movement of the lower pivot of the links 84 past the overcenter position, to thatshown in Fig. 4, the upward bias of the blade spring 88 will act to hold the jumpering device firmly in the position shown. A stop formed by shoulder 93 on the upper end of portion 83 is adapted to engage with the lower edge of the bracket arms 85 to limit the movement of the jumper element 74 towards the rear wall of the cover as th links 84 are snapped past their overcenter position. By simply pulling out on the handle 12 and rocking the lower pivot of the links 84 past the overcenter position against the bias of the spring 88, the contact prongs will again be spread apart enabling the withdrawal of the jumpering device from the cutout box.

An additional advantage of the last described modification of the invention is that the flexible conductor Tl may be replaced by a conventional type of fuse link of a low rated capacity for in\ terrupting small load currents. The device may therefore be used as an auxiliary circuit interrupting means and when so equipped and attached to the side of a cutout box in the manner shown, the regular door with the attached fuses may be withdrawn from the cutout to transfer the load current to the small fuse link to the jumper device. The latter fuse link will be melted and the resultant arc will be immediately interrupted by expulsion action. It will be observed that the cover H is open at the bottom end so that the arc gases may be discharged freely from the lower end of the expulsion tube.

Having described my invention in what I consider to represent preferred embodiments thereof, I desire to have it understood that the specific forms shown are merely illustrative and that the invention may be carried out by other means.

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

1. A jumpering device for interconnecting a pair of terminals of an electrical device comprising an insulating handle, a pair of spaced relatively movable contacts mounted on said handle, means electrically interconnecting said contacts, and means including said handle for moving one of said contacts relative to the other.

2. A jumpering device for interconnecting a pair of terminals of an electrical device comprising an insulating handle, a pair of spaced relatively movable contact prongs mounted on said handle and extending laterally with respect thereto at one end thereof, means electrically interconnecting said contact prongs, and means including said handle for moving one of said contact prongs relative to the other.

3. A jumpering device for interconnecting a pair of terminals of an electrical device comprising a longitudinal insulated handle, a pair of spaced laterally extending contacts mounted on one end of said handle, one of said contacts being movable longitudinally with respect to said handle, means for maintaining said movable contact in alignment with the other of said contacts, and means including said handle for shifting said movable contact relative to the other.

4. A jumpering device for interconnecting a pair of terminals of an electrical device comprising a longitudinal insulating handle, a pair of spaced relatively movable contacts having angularly disposed prongs extending laterally of said handle and mounted on one end thereof, spring means arranged between said contacts for biasing said contacts apart, means including an insulating sleeve around said handle for engaging said movable contacts and forcing said contacts together.

5. A jumpering device for interconnecting a pair of terminals of an electrical device comprising a longitudinal insulating handle, a pair of spaced relatively movable contacts extending laterally from one end of said handle, guide means for maintaining said contacts in a prede termined alignment, and means including said guide means for moving one of said contacts relative to the other.

6. A jumpering device for interconnecting a pair of terminals of an electrical device comprising a longitudinal insulating handle, a pair of spaced relatively movable contacts mounted on one end of said handle and extending laterally with respect thereto, means for maintaining said contacts in alignment, a screw secured to said handle and cooperatively threaded into one of said contacts whereby the separation between said contacts may be adjusted by rotational movement of said handle.

'7. In combination with an electric circuit interrupting device including an insulating casing having a pair of spaced line terminals mounted therein and openings in said casing adjacent said terminals, a jumpering device having a pair of spaced contact prongs, means electrically interconnecting said contact prongs, an insulating support for said contact prongs, said contact prongs being relatively movable on'said support with respect to each other, means on said support for adjusting the spacing between said contact prongs, said contact prongs being of a length sufficientto engage said spaced line terminals throughsaiol casing openings.

8. In combination with an electric circuit interrupting device including an insulating casing having a pair of spaced line terminals mounted therein and openings in said casing adjacent said terminals, an auxiliary electric device having a pair of spaced terminals, means electrically interconnecting said spaced terminals, an insulating support for said spaced'terminals, means including said'support for adjusting the separation between said spaced terminals, said terminals being anguiarly disposed with respect to each other and to said support, said terminals being adapted for insertion into said casing openings, said terminals being furthermore adapted to engage with portions of said sing adjacent said openings whereby adjustment of said su port will force said spaced terminals into wedging contact with said spaced line terminals.

9. In combination with an electric circuit interrupting device including an insulating casing having a pair of spaced line terminals mounted therein and openings in said casing adjacent said line terminals, an auxiliary electric device having a pair of spaced contact prongs, an insulating support for said contact rongs, means electrically interconnecting said contact prongs, one of said contact prongs being movable with respect to the other, said contact prongs being an gularly disposed with respect to each other and with respect to said support, said contact prongs being adapted for insertion into'said casing openings and to engage with portions of said casing in said openings whereby movement of said prongs relative to each other by actuation of said support will force said contacts into engagement with said spaced line terminals.

10. A jumper device for attachment to a cutout or like apparatus having a pair of spaced terminals adjacent openings through a wall of an insulating housing therefor, said device comprising an insulating cover, a pair of contact prongs for insertion through said openings into engagement with said terminals, a support for said contact prongs, said contact prongs being relatively movable with respect to each other on. said support, and means for adjusting said contact prongs to secure said device to said housing.

11. A jumper device for attachment to a cutout or like apparatus having a pair of spaced terminals adjacent openings through a wall of an insulating housing therefor, said device comprising an insulating handle, a pair of contact prongs for insertion through said openings into engagement with said terminals, said contact prongs being mounted for movement relative toward each other on said handle, the ends of said contact prongs being bent at an angle with respect to each other, means for effecting movement of said contact prongs relative to each other following insertion thereof through said openings, the sloping surfaces of the ends of said contact prongs engaging with the inner corners of said housing Wall whereby said contact prongs are forced with a wedging action against said spaced terminals.

12. A jumper device for attachment to a cutout or like apparatus having a pair of spaced ter minals adjacent openings through a wall of an insulating housing therefor, said device comprising an insulating cover, a pair of contact prongs for insertion through said openings into engagement with said terminals, a support for said contact prongs, said contact prongs being relatively slidable toward each other on said support, springmeans normally biasing said support away from said cover, an overcen'ter linkage securing one end of said support to said cover, said 5 ring means and said linkage being so arranged whereby said device is held attached to said housing when said contact prongs are inserted through said openings and said cover portion toward said housing.

13. A jumper device for attachment toa cutout or like apparatus having a pair of spaced terminals adjacent openings through a wall of an insulating housing therefor, said device comprising an insulating cover, a pair of contact prongs for insertion through said openings into engagement with said terminals, a flexible conductor connecting said pair of contact prongs, a support for said contact prongs, said contact prongs be ing relatively movable toward each other on said support, means for mounting said support in said cover whereby said device is held attached to said housing when said contact prongs are inserted through said openings and said cover pushed toward said housing.

14. A jumper device for attachment to a cutout or like apparatus having a pair of spaced terminals adjacent openings through a Wall of an insulating housing therefor, said device comprising an insulating cover, a pair of contact prongs for insertion through said openings into engagement with said terminals, a flexible conductor connecting said contact prongs, a support for said contact prongs, said contact prongs being relatively slidable toward each other on said support, overcenter linkage means mevably supporting one of said contact prongs 011 said cover, spring means pivotally supporting the other of said contact prongs upon said cover, said spring means normally biasing said contact support away from said .cover said spring means and said linkage being furthermore so arranged whereby said device is held attached to said housing when said contact prongs are inserted through said openings and said cover pushed toward said housing.

SIDNEY R. SMITH, JR.

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