US2637795A

US2637795A - Temporary load switch

Info

Publication number: US2637795A
Application number: US235640A
Authority: US
Inventors: Hubbard David Charles
Original assignee: AB Chance Co
Current assignee: AB Chance Co
Priority date: 1951-07-07
Filing date: 1951-07-07
Publication date: 1953-05-05
Anticipated expiration: 1970-05-05

Description

May 5, 1953 D. c. HUBBARD 2,637,795-

' TEMPORARY LOAD SWITCH Filed July '7, 1951 3 Sheets-Sheet l May 5 1953 m. c. HUBBARD 2,637,795

TEMPORARY LOAD SWITCH Filed July 7, 1951 s sheets-sheet 2 IN V EN TOR.

May 5, 1953 y D. c. HUBBARD 2,637,795

TEMPORARY LOAD SWITCH Filed July '7, 1951 :s sheets-sheet 5 Patented May 5, 1953 TEMPORARY LOAD SWITCH David Charles Hubbard, Centralia, Mo., assigner to A. B. Chance Company, Centralia, Mo., a corporation of Missouri Application July 7, 1951, Serial No. 235,640

(Cl. ZOO- 146) 4 Claims.

The present invention relates to temporary Aload switches, and is particularly concerned with the provision of an improved switching device for linemen, which will permit them to make either a connection or a disconnection to an energized ,circuit at a time when there is a possibility oi current iiow through the junction.

One of the objects of the invention the provision of a switching device intended for tem- Vporary installation which can be used for intergrupting the iiow of current and for initiating flow of current by connection to an already energized circuit.

According to the present practice, when it is necessary to make a connection to or disconnccm tion lfrom an energized line under conditions which may involve initiating the flow of current or disrupting the flow of current, operators have had a choice of three alternatives according to the prior art.

1. The operator may open switches or circuit `breakers ahead of the connection point where the Work is to be done and so stop the i'low of current at that point. The objection to this procedure is that lthe switches or circuit breakers to be opened may be at a distance, and a loss of time is involved in the switching operation as well as a loss of revenue and of customer .good lwill during the interruption oi the circuit.

Therev is also -a safety hazard involved, depending upon the proper coordination of all personnel and upon the proper choice of switches `and choice of switching time.

2. The second alternative consists in breaking or disconnecting the connectors by hot line methods alone, involving the use of tools carried by long insulating poles. The objections to this method are that they may involve pitting and :burning of the conductor and the connector, there is a possibility of establishing a long arc when effecting a disconnect and this arcy due to wind or other factors, may strike grounded .equipment or carry over to another energized conductor, with resultant power failure and possible severe damage and injury lto personnel.

3. The third Yalternative consists in the installation of disconnect switches at each point where equipment is installed and at each point Where there are branch feeders. This is `objectionable because of the increased cost of distribution construction and increased maintenance cost.

All of the foregoing objections may be elimif nated by the use of the present temporary load switch, which may be installed temporarily at any point where it is desired to effect a connec- 2 tion or a disconnection to an energized line under possible current flow conditions without going to the expense of permanent disconect switches, without danger of establishing long arcs, and without pitting o r burning the conductors or connectors.

Another object of Vthe invention is the provision of an improved load switch which may be used to break the circuit inside an insulated tube which coniines the arc and gases to the inside of the tube, and to established discharge ports that permit the exhaust of the gases in `directions that are safe for the operator.

Another object of the invention ,is the provision of an improved temporary load switch which includes means for eiecting a connection through a fuse whenever that is deemed advisable, so that if a fau-lt still exists on the line the fuse will blow ,and protect the line and other equipment.

Another object of the invention is the provision of an improved temporary load switch construction which includes a minimum number of parts, which is simple in construction, sturdy, and capable of being used over and over again for interrupting or establishing heavy currents under conditions which involve maximum safety because of the operations all being performed at the same location.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the drawings, of which there are three sheets, accompanying the specification,

Fig. l is a side elevational view partially broken away to reduce the length of the drawing, showing a temporary load switch embodying the invention;

Fig. 2 is a fragmentary sectional view taken on the plane of the line 2-2 of Fig. l, looking in the direction of the arrows;

Fig. 3 is a fragmentary side elevational view of the lower ejector arm fixture in partial section with vthe switch blade omitted;

Fig. 4 is a top plan view of the cable ejector;

Fig. 5 is an enlarged fragmentary view similar to the lower end of Fig. l, showing the details of vattachment of the cable to the cable ejector lever;

Fig. 6 is a fragmentary side elevational view taken on the plane of the lline i-l of Fig. 1, showing the construction of the upper cable sup,- porting Xture which also carries a fixed blade Contact;

Fig. 7 is a similar fragmentary sectional view taken on the plane of the line l--i through the same part of the mechanism as 6, showing the internal construction of the cable gripping lever;

Fig. 8 is a view in perspective of the blast deflector which is used in Figs. 6 and 7;

Fig. 9 is a view in perspective of the fixed contact for engaging the switch blade;

Fig. 10 is a fragmentary sectional view taken on the plane of the line Ill-itl of Fig. '7, looking in the direction of the arrows;

Fig. l1 is a fragmentary sectional View similar to Fig. 5, showing an alternative mode of securement for the lower end of the cable;

Fig. l2 is a fragmentary sectional view taken on the plane of the line i2-l2 of Fig. l, looking in the direction of the arrows, showing the details of attachment of the upper fixture to a standard tap clamp at the connector aperture;

Fig. 13 is a fragmentary sectional view taken on the plane of the line iii-i3 of Fig. l, looking in the direction of the arrows;

Fig. 14 is a fragmentary sectional view taken on the plane of the line Ill-I4 of Fig. 3, showing an alternative assembly in which a connector bolt is employed;

Fig. 15 is a fragmentary sectional. View taken on the plane of the line lE-i of Fig. l, looking in the direction of the arrows.

Referring to Fig. l, the present temporary load switch is preferably provided with a tap clamp connector 26B for connection to the transmission line conductor. Such tap clamps are frequently used for temporary connections and various types of tap clamps may be employed.

For example, the tap clamp may have an upper xed jaw member 2i and a lower movable jaw member 22. The upper fixed jaw member 2i may have a flat body ange 23 provided with a relatively large circular aperture 24 for receiving a clamp stick or the headed pin which is carried by the end of a disconnect stick.

The body ange 23 carries the laterally projecting flanges 25, 26, which form parts of a V- shaped groove for engagement above a line conductor 2, these flanges projecting from both sides of the flat body 23 to provide an elongated groove engaging the conductor.

The upper xed jaw 2i customarily has a pointed beak 28, the lower guiding surface 29 of which guides the clamp over a conductor, and the body 23 supports a lower forwardly projecting arm 34, having a threaded bore 3l for receiving the threaded shank 32 of an eye bolt 33.

Eye bolt 33 has a ring or eye structure 34 at its lower end for engagement with a clamp stick, but in some embodiments of the invention the bolt 33 may be provided with a long insulated wooden handle permanently replacing the clamp stick.

The movable jaw 22 has a partially circular or V-groove 35 opposing the upper groove 36, and may be mounted for rotation upon the upper end 3l of the eye bolt 33, so that the eye bolt may rotate on the jaw 3l.

The lower jaw 22 is guided in its sliding movement by guide flanges 3B engaging the opposite sides of a guide rib 39. I prefer to use a standard tap clamp, the body of which is provided with a circular through bore 44, surrounded by a conical depression 4i, for receiving the usual apertured connector bolt.

In order that the eye bolt 33 or its wooden handle may extend laterally in an accessible manner and so that the temporary load switch may extend downwardly to be actuated by means of a downward pull, the upper fixture 42 of the temporary load switch is preferably provided with a diagonally turned supporting lug 43 at its upper end. This supporting lug 43 may be generally hexagonal in cross section.

While lug 43 is generally hexagonal, it is so shaped on its under side that it has a V-shaped ridge fitting in the grooves of the tap clamp body. Lug 43 supports an integral lateral screw bolt extension 44 with a threaded end 45 for receiving a nut 46.

The integral screw bolt extension 44 replaces the usual apertured connector bolt in the aperture 40, and the hexagonal lug 43 rests against the groove 47 in the connector portion of the body 23, which grooves are usually employed for engaging the conductor.

The nut 4G engages the ilat thrust surface 48 on the other side of the connector body and draws the lug 43 tightly against the body of the tap clamp. Thus the present temporary load switch is adapted to utilize any standard type tap clamp meeting these specications because it can be attached to the tap clamp in place of the usual connector bolt.

The upper fixture 42 for the ltemporary load switch comprises a cast metal member having a cylindrical body portion 49, Fig. l0, at its left side, which portion is provided with a cylindrical bore il for receiving a reduced cylindrical portion 5i of the insulating fiber tube 52. The tube is secured in this bore against the upper end 53 of the bore by one or more transverse metal pins 54 riveted in place and traversing the junction between the tube and the wall of the bore.

The cylindrical portion of the fixture 42 carries a pair of laterally projecting pivot flanges 55, 56, at the lower end of the tubular portion, these pivot flanges having through bores 5l serving as bearings for a screw bolt 58.

Screw bolt 53 is prevented from turning by a squared portion 59 on its shank and by the bore 571 being complementary in shape. The screw bolt 58 also carries a blast guard El), shown in perspective in Fig. 8.

The blast guard is a substantially U-shaped sheet metal member formed with relatively square corners, and having a pair of attaching flanges El, 62 provided with the squared aperture 63 in one and the round aperture 64 in the other. The squared aperture S3 fits the squared shank 59 on the bolt 58, aiding in holding the guard with its curved groove 55 tightly against the side of the tube 52, to which it is complementary.

The attaching flanges 5I, 62 of the blast guard @il are carried by the lower at body 66, which covers the lower end of the fixture 42 between the pivot anges 55 and 56, and prevents any downward blast of escaping gases resulting from the arc. Use of the guard also eliminates the necessity for trying to machine the parts about the flanges 55, 56 in such manner as to prevent escape of gases.

The bolt 58 also supports a fixed contact 67, forming part of a knife blade switch, the blade of which is indicated at G8 in Fig. 1. This xed contact comprises a strip of suitable resilient sheet metal of high conducting qualities, such as a copper alloy, which has a at attaching portion 69 at its left end in Fig. 9, provided with a squared aperture 'l0 for the squared portion 59 of bolt 58.

The Width `of the fixed contact flange 69 is preferably such that its lower edge 1| strikes the insideof the bottom yoke 66 of'the guard 60. Thus the squared aperture and engagement with the guard assure the fixed contact 61 being held against rotation.

Attaching flange S9 or xed contact 61 is pref.- erably curved outwardly at 12 and provided with a partially cylindrical portion 13, bringing its nat 'engaging portion 14 generally parallel to the side of the xture body 42. The fiat portion 14 is resiliently urged toward the fixture 42 by the curved part 13, and is initially spaced a distance less than the thickness of the blade E8, so that blade 68 will be tightly engaged between fixed Acontact 61 and the cylindrical part 49 of the fixture.

The fixed contact is also bent outwardly at `15, having a diverging blade guiding part `i6 to insure vthe blade passingl into the groove 11. Fixture 42 carries an integral blade stop 49a 0n its cylindrical portion 49, thus preventing the blade |38 from hammering against clip 61, which would gradually open and lose its gripping action. The fixture 42 is closed above the tube 52 by an upper wall `1.8, which forms part of a clamp lever hous.- ing 19.

'The bolt 5 8 pivotally supports a spring pressed .clamp lever `80. This clamp lever comprises a cast metal member having flat sides ,81, 32, itting between the anges 5,5, 56, and provided with a circular bore 83, serving as a bearing on bolt 58.

The bolt 58 then passes through the following parts, beginning at the top of Fig. l;

First the bolt passes through flange 62 of the f.

the guard ange 6|, after which it is provided The washer may be with a washer and a nut 84. a spring lock washer.

Clamp lever 80 has a lower substantially cylindrical hub portion 85 about the bore 83, and has an upwardly extending arm 86 carrying a laterally extending arcuate clamping lug v81. The arcuate clamping lug 81 preferably has its 4for- `ward end -provided with a convex surface 88 terminating in a point S9, where the maximum clamping pressure is exerted.

vCurved surface 88 and point v89 are adapted to engage a twisted multiple strand conductor cable 90, to press it against the inner plane surface 9|, inside the housing 19, against which the table 90 is clamped.

The pivot anges and 56 of the xture 42 are .extended upwardly to an arcuate top wall 9 2, which ,extends to the right in Fig. 7, and is .also arcuate on the inside at 93 to permit movement cf lever 80.

Arcuate top wall S2 has an abrupt shoulder 94, spaced from and behind the lever 80 at the right .0.f Fig, 7, Vfor limiting the movement of the lever a clockwise direction. The top wall also includes a slightly lower portion 95, with a downwardly extending end wall 95, having a slanting surface -91 for retaining one end of a helical compression spring 9,8. The other end of this compression spring, which is loosely wound, is seated upon an integral lug 99, carried by the rear edge V,|00 `of` the clamp lever 80.

I'he clamp lever 80 also carries an outwardly extending actuating arm |0|, Fig. '7, which ex- ,tends out between the side walls |02 of the housing 1,9, and is formed with an upwardly turned end |03 to provide a hook recess y|04 for 6 engagement with a clamp stick or disconnect stick.

The full line position of clam-ping lever 80.-in Fig. '7, is that which it assumes when it is .clamping a conductor cable 90, and the dot-ted line position is that to which it is moved by a clamp Stick or disconnect stickv by exerting a downward pull on the arm 10| to release the cable 90.

The insulating tube 52 has a cylindrical bore |05, and is made of the multiple layer insulating fiber of which fuse tubes are usually constructed. It is open at its lower end |06 for discharge oi gases, and the clamp lever housing 19 also preferably has a lateral opening or window |01, Fig. 6, located to expose the clamped end of the cable and the clamping end portion 88 of the clamp lever 80.

This Window opening is bordered by outwardly beveled wall portions |08 and may be rectangular in shape, projecting laterally from the iixture 42 by means of a three-sided wall |09 to direct escaping gases laterally of the fixture and tube.

The window also permits the cable to be seen after it has been inserted into the clamping position so that the operator can see it as he clamps it to check its clamped condition.

The tube 52 carries a lower electrically .conducting fixture ||0, Fig. 1, preferably spaced slightly from the lower end |08, due to the 1depending arm IH of the fixture H0.

Lower fixture may comprise a .cast metal member formed with a substantially cylindrical body I2, having a cylindrical b-ore H3, Fig. 2, of sufficient size to receive the insulating tube 52.

The fixture is secured on the insulating tube by a transverse riveted pin H4, so located at one side of the cylindrical portion` ||2 that the pin intersects the tube 52 as it passes through the nxture to prevent removal of the fixture from the tube or to prevent relative rotation.

Cylindrical body I |2 preferably has a laterally projecting lug l5, the upper surface i6 of which serves as a stop for the switch blade 58 when it has been moved to the open-'line position of Fig.

Cylindrical body I l2 lalso supports the laterally projecting connector portion ||1, Fig. 2, which has a partially conical bore IIS vand a pairof aligned V-grooves H9. The connector portion ||1 has a flat surface |29, surrounding the circular bore |2|, which ordinarily receives an apertured connector bolt |22.

Such a connector bolt |22 has a transverse aperture |23 at its upper end for receiving a conductor |2, which is clamped against the `V- grooves |59 by pulling the shank 225 inward by means of a nut |26. The connector bolt is .employed as shown in Fig. 14 when it is desired to attach a juncture wire to the connector ||1.

Figs. 2 and 3 show an alternative assembly in Vwhich a specialstud bolt |21 is employed. This bolt has a cylindrical body |28 yand a narrow circular head |29 for receiving the ta-p clamp of a fused tapper. A fused tapper is used whenever it is desired to include a fuse in the circuit by means of the special stud'bolt |21.

In some embodiments of vthe invention the special stud |21, including only a head |29, may be cast as ran integral part of the xture H0, eliminating the connector I1, and extending outward toward the right i-n Fig. l parallel to switch blade G8.

Stud bolt |21 also has a cylindrical shank |30 which passes through the connector portion 1, and it has a pair of `laterally projecting integral lugs 3| which are clamped in the grooves ||5 by -nut |32. `'I'hus the special stud bolt |21 may be xedly clamped in the connector part of. the lower fixture and usedforv attaching a fused .tapper to interpose a fuse in the circuit.

- The multiple strand, flexible cable 90, which is employed is usually preferably not provided with a fuse and it may be used over and over again except for such end portions as may become Yburned and may be cut off.

` `.The lower conducting xture H also has a rlaterally projecting arm |33, comprising a relatively flat web. |34, bordered by laterally projecting upperand lower reinforcing iianges |35, |36. The arm |33 supports a substantially cylindrical hub |31, with a cylindrical bore |98 forming a bearing for a switch blade pintle |39, coinprising a screw bolt. kThe arm |33 preferably has an offset at |40, adjacent the hub |31, so that the thrust surface 414| vof hub |31 may be located substantially in `the plane of the same side of the upper fixture 42, lso that the switch blade may best effect connection between the upper and lower xtures.

Switch blade `6B may consist of an elongated rectangular sectioncopper bar which is provided intermediate its ends, but closer to the lower end -with a through bore |42 forreceiving the screw bolt |39. f Screw bolt |39 passes through the hub |31 and blade 68, and is provided with a nut and with one or more spring clamp washers |43 on each side of the blade and fixture to establish a tight .electrical connection -between blade |38 and xture H0 at all times, and to hold the blade -frictionally in any position to which it may be moved.

The length of the blade 58 is sufficient so that it extends from the lower fixture Iii) longitudinally of the tube 52 into engagement with and beyond the fixed contact 51. The blade G extends downwardly below the screw bolt |39 sufciently to mount a cast metal ring fixture |44 andcarries a similar ring fixture |45 adiacent its upper end but spaced from the xed contact B1.

Each ring fixture |44, |45 is fixedly secured to blade 68 on the same side as the other in the same way except that the rings extend in opposite directions. Thus the ring |44 extends to the left to effect a closing of the switch blade '58 by a down pull, while ring |45 extends to the right to `permit an opening pull to be exerted on the upper end of the blade.

The switch blade BB is now adapted to establish a connection from the upper conducting fixture42 to the lower conducting fixture |63 which is in -parallel with the braided cable 90. Thus the switch may be used to close the circuit when the temporary load switch is used with an empty tube, or it may be used preliminary to the opening of the circuit by means of the release of the braided cable 90. The laterally projecting arm |33 of the lower fixture l0 has a diagonally Iand downwardly lex tending portion |50. This portion consists also of a pair of webs |5|, |52, with reinforcing ribs |53, |54. The ribs |53, |54 merge into a thick end portion |55 of the arm |50, which is -provided with a through bore |56 for receiving a screw bolt |51.

yejector arm |59.

Screw lbolt |51,.has a cylindrical shank which slidably and rotatably engages a slot |58 in an The screw bolt |51 has. alreduced threaded portion which is threadedinto the bore |55, leaving the enlarged portion which flts the slot |58 of predetermined length,`.tting the width of the ejector lever |59.

A washer |60 on the screw bolt |51 aids in guiding the ejector arm |59, which must slide freely and also pivot freely. The lower end of the thickened portion |55 may beformedwith serrations, such as a ridge IGI, at the juncture of two diagonal surfaces |52, |53. These surfaces are `for clamping the braided cable 90.. l

The spring is initially tensioned so that it draws the ejector lever |59 up against the end of the tube 52, and also tends to pivot the ejectoi` lever in a clockwise direction when the bOlt|51 is in the lower end of slot |58.

Ejector lever |59 also has a laterally extending linger |13 at its right end, with an upwardly 'con- Vex portion |14 for receiving the stranded cable 90 as it is bent backward and upward upon emerging from the tube 52.

The mode of installation of the stranded cable 90 is as follows:

One end of the cable is inserted in the bottom |06 of tube 52, andthe cable has sucie'n't Stiffness to be pushed into the tube until it 'appears at the window |01. The clamping lever is retracted from the adjacent inner surface ofthe fixture by pushing down on' the actuating enelv |0| so that the cable may beV pushed up under the end of lever 80.

The lever is permitted to be forced against the cable, as shown in Fig. 1, by means of its spring. The upper end of cable is thus secured in the upper conducting fixture 42 and the cable is then passed under the curved portion |14 of the ejector lever |59 and pulled taut until the end ofthe ejector lever strikes the end of the tube. y

The cable is then passed upward over the top of the clamping ridges |1|, |12 of the ejector lever, behind the web |64 and under the ridge |6|. At this time these clamping surfaces may be separated by pushing down lon the tail |69 and upon releasing the tail |59 with the cable held illlt, thte cable is 1clamped with the ejector lever ,so ensl'oned hat it tends o out of the'tube. t draw the cable l The circuit may be broken at any timefby pulllng down on the actuating arm |0| of the clamplng lever 80, releasing the upper end of the cable whereupon the cable is pulled out of the tube to brar the circuit in the tube.

e resulting arc and gases are dischar A of the bottom of the tube and laterallygic`1 iczjllll window |01, extinguishing the arc without danger Liegt-he operatorf1 who is preferably located at some 1 ance an w o manipulate th' clamp stick. s 1s devlce ;W 1.th a

In another modified form of the invention; shownin Fig. ll, theejector lever is of the simple pivoted type without the slot or clamping surfaces, but having a thumb screw connector on the end of the bolt icl, under which the cable is clamped.

The cable being clamped at the center of rotation of the ejector lever, there is practically no sliding movement of the cable on the end portion |14 of the lever, and 'a minimum amount of fric# tion so that the ejector lever may pull out the cable yas quickly as possible. The specific mode of releasing the cable and breaking a circuit has been previously described, and the following is a description of the mode of manipulation of the temporary load switch for safely breaking circuits under load or for conricting circuits under load.

Whenever a circuit is to be disconnected under load, the following steps should be taken.'

1. A flexible, braided conductor should vbe installed in the tube and clamped above and be lower under tension as described..

2. The switch blade t3 should be closed into engagement with the clip or fired contact ,67.

3; A temporary jumper conductor should be connected to the terminal connector 43.

4. The permanent connection from line to equipment which is to be broken and removed, is now by-passed by connecting the tap clamp 2U to one side of this connection and connecting the temporary jumper to the other side of this permarient connection, using hot line tools.

5. The Toy-passed permanent connection. is now disconnected with hot line tools, butthe load is temporarily carried through this temporary load switch.

6. A disconnect pole is inserted in the ring 45 and the blade 58 is opened by means of a down'-V ward p ull until it engages stop IIS. The entire load now passes through the braided cable conductor 9i).

7. vUsing the same disconnect stick, the stick is applied to the actuating arm mi of the clamp-ing lever Si); and a light downward pull releases the upper end of the cable Bil. This breaks the circuit safely within the tube 52.

8; The temporary load switch is now removed by removing the clamp 2li and by disconnecting the by-passing jumper.

In brief, the permanent connection has been s disconnected without hazard by by-'passing it with this temporary load switch, then disconnecting it' while theload carried' by the switch, then-opening the blade of the switch and breaking the'circuit at the cablev inside the tube.

Vvhen an energized circuit is to be connected to anotherline'or equipment under conditions which nfay involve the flow of current, the temporary load switch may also be employed. This may occur whenever it is necessary to make a connection'v directly to a transformer or to a bank of transformers to which a load was previously attached: or a feeder may similarly be reconnected through this switch after storm damage or whenever an unknown consumer load is still present o`r"1' the circuit.

Such a load makes it hazardous to connect a feeder directly to an energia/edl line by means of clamps because the application of a clamp to the linemay not'be accomplished without some rattling about of the clamp on the line, which results in'arcing, burning andl pitting of the clamp and the conductor.

The mode ofl manipulationof the tool' to con;

I0 n ect to an energized line under load is as follows:

1. The switch blade 68 is moved to the open position against the stop lit. The flexible braided cable 9c is omitted and the tube is empty.

2. A temporary jumper is attached to the lower fixture lic at its connector.

3. The temporary jumper is connected to the feeder transformer or other equipment.

4. Using a conventional hot line tool the tap clamp 26 is then attached to the energized circuit.

5. The blade t8 is closed by means of a disconnect stick, pulling down on the ring Idil. The short lever arm of the ring 144 and the resisting friction of the blade give the blade a snap action in closing. The new circuit has now been energized under load.

6. A permanent connection for the new circuit or equipment is now installed with hot line tools, by-passing the temporary load switch.

'7; The temporary switch and temporary jumper are now removed.

Wherever there may be a fault still existing on the line, it may be desirable to provide fuse protection in series with the temporary switch. This can be done by using the special stud |21 in the lower connector I Il, vand by hanging a fused tapper on this stud so that the temporary jumper can be attached to the lower end of the fused tapper.

The circuit, when closed by the blade $3, now passes through a fused tapper as well as the temporary load switch. If a fault still exists on the line the fused tapper will blow, cutting out the circuit and preventing damage to the other equipment.

1t will thus be observed that I have invented an improved temporary load switch which permits the disconnection of high voltage circuits under load under safe conditions at any point where it is desirable to eifect a disconnection.

It is also capable of being used in connecting circuits where there may be a possible load, without hazard, and it may also be used to connect circuits where a fault still exists by including a fused tapper in the circuit.

vVhile I have illustrated a preferred embodiment of my invention, many modications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

l. A' temporary loadbreak switch comprising. an insulating tube provided at its lower end with a metal fixture fixedly secured on said at a point spaced from its end, said fixture being provided on one side with a conhector for attachment to a conductor and eX- tending in the opposite direction and downwardly toward the end of the tube, a pivot pin carried by downward end of said fixture, and said fixture presenting a downwardly ridged surface, and an ejector lever provided with a slot pivotal and sliding movement on said pivot pin, said ejector' lever presenting an upwardly grooved surface opposite said ridged surace for clamping the end of a cable, and saidl ejector lever extending to a point adjacent the open lower end of said tube' and having a laterally projecting arm engaging above said cable, spring means engaging said ejector lever on its side opposite to the tube and tensioning said ejector lever so that it its end adjacent said tube tends to pull the cable out of said tube, and said spring also urging said ejector lever to clamp the end of said cable, a second xture carried by the` upper end of said tube, said second xture comprising a tubular metal member secured to said tube, and having a ilat arcuate extension projecting laterally, said arcuate extension having a pair of parallel walls supporting a pintle member at the center of its arc, and said pintle pivotally supporting a radially extending lever having an arcuate clamping extension projecting above the end of said tube, and having an outwardlj7 projecting actuating end curving upwardly, a compression spring in said arcuate extension urging said lever into clamping engagement with the side wall of said upper fixture, and a cable in said tube, having its upper end clamped against Said side wall by said lever and its lower end subjected to tension by said ejector lever.

2. A temporary load break switch comprising an insulating tube provided at its lower end with a metal xture fixedly secured on said tube at a point spaced from its end, said 'iixture being provided on one side with a connector for attachment to a conductor and extending in the opposite direction and downwardly toward the end of the tube, a pivot pin carried by the downward end of said fixture, and said 'fixture presenting a downwardly ridged surface, and an ejector lever provided with a slot for pivotal and sliding movement on said pivot pin, said ejector lever presenting an upwardly grooved surface opposite said ridged surface for clamping the end of a cable, and said ejector lever extending to a point adjacent the open lower end of i said tube and having a laterally projecting arm engaging above said cable, spring means engaging said ejector lever on its side opposite to the tube and tensioning said ejector lever so that its end adjacent said tube tends to pull the cable out of said tube, and said spring also urging said ejector lever to clamp the end of said cable, a second fixture carried by the upper end of said tube, said second fixture comprising a tubular metal member secured to said tube, and having a flat arcuate extension projecting laterally, said arcuate extension having a pair of parallel walls supporting a pintle member at the center of its arc, and said pintle pivotally supporting a radially extending lever having an arcuate clamping extension projecting above the end of said tube, and having an outwardly projecting actuating end curving upwardly, a compression spring in said arcuate extension urging said lever into clamping engagement with the side wall of said upper xture, and a cable in said tube, having its upper end clamped against said side wall by said lever and its lower end subjected to tension by said ejector lever, the said latter pintle also supporting a substantially U shaped blast guard, the yoke of which extends below said pintle and below said lever to prevent the downward blast of gases past said lever.

`3. A temporary load break switch comprising an insulating tube provided at its lower end with a metal fixture fixedly secured on said tube at a point spaced from its end, said fixture being provided on one side with a connector for attachment to a conductor and extending in the opposite direction and downwardly toward the end of the tube, a pivot pin carried by the fis downward end of said xture, and said fixture presenting a downwardly ridged surface, and an ejector lever provided with a slot for pivotal and sliding movement on said pivot pin, said ejector lever presenting an upwardly grooved surface opposite said ridged surface for clamping the end of a cable, and said ejector lever extending to a point adjacent the operi lower end of said tube and having a laterally projecting arm engaging above said cable, spring means engaging said ejector lever on its side opposite to the tube and tensioning said ejector lever so that its end adjacent said tube tends to pull the cable out of said tube, and said spring also urging said ejector lever to clamp the end of said cable, a second iixture carried by the upper end of said tube, said second fixture comprising a tubular metal member secured to said tube, and having a at arcuate extension projecting laterally, said arcuate extension having a pair of parallel Walls supporting a pintle member at the center of its arc, and said pintle pivotally supporting a radially extending lever-.having an arcuate clamping extension projecting -above the end of said tube, and having an outwardly projecting actuating end curving upwardly, a compression spring in said arcuate extension urging said lever into clamping engagement with the side walll of said upper ixture, and a cable in said tube, having its upper end clamped against said side wall by said lever and its lower end subjected to tension by Said ejector lever, the said latter pintle also supporting a substantially U shaped blast guard, the yoke of which extends below said pintle and below said lever to prevent the downward blast of gases past said lever, the said pintle comprising a screw bolt and nut, and said screw bolt also clamping the attaching end of a resilient spring and contact which extends about said xture close to the side thereof and is provided with an outwardly flaring end for guiding a switch blade, and a switch blade pivoted on said lower xture and frictionally held against rotation by a clamping bolt, the said switch blade engaging said upper contact and swinging downwardly for disengagement.

4. A temporary load break switch comprising an insulating tube provided at its lower end with a metal xture fixedly secured on said tube at a point spaced from its end, said fixture being provided on one side with a connector for attachment to a conductor and extending in the opposite direction and downwardly toward the end of the tube, a pivot pin carried by the downward end of said fixture, and said fixture presenting a downwardly ridged surface, and an ejector lever provided with a slot for pivotal and sliding movement on said pivot pin, said ejector lever presenting an upwardly grooved surface opposite said ridged surface for clamping the end of a cable, and said ejector lever extending to a point adjacent the open lower end of said tube and having a laterally projecting arm engaging above said cable, spring means engag-` ing said ejector lever on its side opposite to the tube and tensioning said ejector lever so that its end adjacent said tube tends to pull the cable out of said tube, and said spring also urging said ejector lever to clamp the end of said cable, a second fixture carried by the upper end of said tube, said second iixture comprising a tubular metal member secured to said tube, and having a iiat arcuate extension projecting laterally, said arcuate extension having a pair of parallel walls supporting a pintle member at the center of its arc, and said pintle pivotally supporting a radially extending lever having an arcuate clamping extension projecting above the end of said tube, and having an outwardly projecting actuating end curving upwardly, a compression spring in said arcuate extension urging said lever into clamping engagement with the side wall of said upper iixture, and a cable in said tube, having its upper end clamped against said side wall by said lever and its lower end subjected to tension by said ejector lever, the said latter pintle also supporting a substantially U shaped blast guard, the yoke of which extends below said pintle and below said lever to prevent the downward blast of gases past said lever, the said pintle comprising a screw bolt and nut, and said screw bolt also clamping the attaching end of a resilient spring and contact which extends about said fixture close to the side thereof and is provided with an outwardly flaring end for guiding a switch blade, and a switch blade pivoted on said lower iixture and frictionally held against rotation by a. clamping bolt, the said switch blade engaging said upper contact and swinging downwardly for disengagement, said switch blade extending downwardly past its pivot and being provided with a ring xedly secured thereto, and projecting backwardly from said tube and lower fixture for actuating said blade with a snap action.

DAVID CHARLES HUBBARD.

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