US1923312A - Switch - Google Patents

Description

Aug. 22, 1933. E. H. JACOBS SWITCH Filed March 31 1928 2 Sheets-Sheet 1 Wm WM E. H. JACOBS Aug. 22, 1933.

SWITCH 'Filed March 31, 1928 2 Sheets-Sheet 2 Patented Aug. 22, 1933 UNITED STATES swrron 'Ernest Jacobs, River Forest; 111., assignor to' Electrical Engineers Equipment 00., "Melrose Park, 111., a Corporation of Illinois I Application March 31, 1928." Serial"No. 266,157

9 Claims. -(Cl.:200- 48) My invention relates to electrical switches, more particularly the outdoor gang operated type such as are commonly employed for powerdisconnect purposes. While the. inventioniisiparticularly applicable to this service, it is.not-.intended to limit itto that use.

The preferred embodiment of this invention provides a switch of minimum structure, securing good contact when the switch is closed, easily operable to open or close, andwhichprovides a large separation of the contacts on. opening.

For. outdoor service the contacts .of .the switch must be protected against weatherconditions; and one of the conditions presenting the greatest difficulty is the accumulation of sleet on the contacts. It has been customary heretofore to house one or both of the contactsunder a shelter known as a sleet hood for the purpose of avoiding freeze ing of the contacts together so that theyv cannot be separatedwhen it is desired toopen the switch -ncl also to minimize the difficulties of closing the switch under conditions where sleet-would tend to accumulate on one or more parts. 1

According to the present invention I provide stationary floating contacts and a movable plungrigid contact, although it is within .my invention to reverse the relation of theseparts.

The preferred embodiment presents a minimum of material and labor in construction, resulting in a device of low cost but with. highly'satisfactci'y operating characteristics.

Now in order to acquaint those skilledinlth'e art with the manner of constructing andoperating the device embodying my inventionII shall describe in connection with'the accompanying drawings a specific embodimentof my.,invention.

In the drawings 1 .1 is a side elevational view'oi a sleet'hood crank switch shown in clos'ed position, with the dotted lines showing the open .position of .the parts.

Fig. 2 is an enlarged side elevational view'ot th stationary contacts withithe .side plate oi the sleet hood removed.

Fig. 3 is a horizontal section taken on the line 3--3 of Fig. 2 to illustratethe-construction of stationary contacts and the sleet ,hood, and Fig. d a section on 1ine'44 of Fig. 1.

Referring to Fig. 1, the common basemember 1, which is preferably achannel bariiin inverted position, supportsat its opposite ends stationary insulators 2 and 3. The stationaryinsulatorfl has its pedestal '4' mounted directly on'the inverted web of the channel bar 1, whereasthe insulator 2 has its pedestal 5 mounted upon a spacing block; 6 that i n turn'rests upon the frame member 1. a

'While in Fig. 1 the elements for a single phase only appear. it is to be understood that directly back .of theswitch shownin Fig.1 there ore placed two other identical units for a three phase line the channel bases 1 being-suitably connected together by 'a framework on which the .gang switch mounted. V

. Thecap 'l of insulator 3- contains a base and terminal member flbolted thereto. This base and terminal member 8 carries-a pivot lug 9- for receivinga pivotpin- 10. The base and terminal member 8 also provides a laterally extending arm 11 to which-there is connected a terminal lug 12 of the phase conductor 13. The phase conductor 13 is gripped tothe arm 11 mechanically as by 1 meansof .the U bolt l4. -The flattened part0! the terminal lug 12 is bolted tothearm member 11 as byrmeans. of the bolts -16with the ends I of two flexible ribbons 17 disposed betweenit-and said-arm 11. 7 V V .The stationary insulator 2- has a cap'member 18 which'supports a bracket member 19 thereupon. Thisbrack'et memberlQ is shown on-an enlarged scalein-Eig. 2. It has alaterally extending arm 20 to which by means of the U bolt- 21' the line phase conductor 22 ismechanically bolted. The line phase conductor is electrically connected to enterminal lug-23,. the flattened end of which extends upward at an angle as indicated at-24 parallel'to an angularly disposed portion 25 of the bracket member 19. Bolts 26 extend through the flattened part of theterminal lug at 24 and through the bracket portion 25, and these parts clamp between :them thelower ends of the flexible leads or. copper ribbons 2'7, 28 to make connection'between the (line conductor 22 and the stationary contacts 29 and 30 which are housed and mounted in the sleet hood 31 on top of the bracket 19. e i The sleet hood 31- comprisesa chamber substantially closed on all sides except that: which faces towards the other line. phase conductor 13. On this side it has an opening 33 provided wi'th tapered guiding surfaces'34 and35 and an overhanging porch and roof 36. Preferably the main part of the sleet'hood 31 is cast integralwith the bracket 19 with one side thereof left open to be closed by cover plate 37 held in place by the bolts 38 and '39. Contact members 29.1and '30 comprise stampings of sheet copper orbrass with flaring front 7 ends 40 and 41 lying immediately back oi the tapered inlet opening 33 in such a position as to receive readily and guide into place between them a contact member 42 which is preferably a solid copper cast bar- The forward end 43 of the bar 44 is suitably beveled and milled or ground off parallel so as to provide fiat surface contact with the flat central parts of the contacts 29, 30. The rear ends'of the contacts 29 and'30 are provided with laterally'extending flanges 45 and 46 formed by bending of the body of the sheet metal contacts 29 and 30 at right angles to the main fiat portions thereof. The upper ends of the copper ribbons 27 and 28 are clamped to the flanges 45 and 46 as by means of clamping plates 47, 48 and bolts 49, ,50. The contacts 29 and 30 have upwardly extending lugs 52 and downwardly extending lugs 53 pierced for passage therethrough of the supporting and guid ing bolts 38 and 39. The bolts 38 and 39 have coil springs 54 and 55 mounted thereupongthese springs being held under compression whereby the contact members 29 and 30 are forced towards each other by pressure exerted upon the ears or lugs 52 and 53. The bolts 38 and 39 are spaced far enough apart to permit the passage between them of the forward end 43 of the contact arm 44. The forward ends of the, contacts 29 and 30 are pressed towards each other by compression springs 56 and 57 mounted upon short studs 58 and 59. These springs 56 and 57 are under compression, and they force the contact members 29 and 30 towards each other so as to make good contact with the movable contact member 43.

It will be observed that the pressure of the springs is'applied to; the contacts 29 and 30 at three points'so thatthese contacts may have substantiallyuniversal motion of limited degree to adapt themselves to the sides of the movable contact member 43. Also due to'the pressure being applied at three points and the contacts held at two points against rockingup and down or moving back'and forth an inexpensive universal mounting with evenly applied pressure is secured. A relatively large' amount of sidewise motion or play is permissibledue to the fact that the springs are all under balanced compression so that lack of alinement angularly or'bodily even in considerable amount does not prevent the securing and maintaining of excellent contactbet'ween the stationary and movable contact members.

Due to the overhangingporch 36 of the hood 31 sleet is excluded and yet ample opportunity for the contacts to come into engagement is afforded.

The bar 44 is hinged at its rear end on a pin 61 which'pin is supported at opposite sides of the bar 44 on a pair of links 62. Instead of employing a pair of links a single link may be utilized for the reasonthat the bar 44 secures an independent guiding motion from a movable insulator-63 as will be described more at length later.

The bar 44 has laterally extending lugs 64 at each side and to each of these lugs there is bolted as by means of the bolt 65 the upper end of the corresponding copper flexible ribbon 17.

The lower. ends of they links 62 are hinged on the pin 10. It will be observed that the upper end of the link 62 rises aboutits center-10 as the switch is moved to the open position indicated in dotted lines.

. The rocking insulator. 63 has its pedestal 67 clamped by means of a suitable split clamp to thehollow squared shaft 68. -The hollow squared shaft 68 comprisesa piece of tubing rolled'linto square form, and it is supported in bearings 69 through the intermediary of journal blocks 70 which preferably are brass cylinders with suitable rectangular openings therethrough for receiving the squared shaft 68. The bearing pedestal 69 has a sleeve 71 of larger size than the brass cylinder 70, and it is adapted to receive Babbitt metal or the like. To prevent endwise shifting of the hollow square shaft collars may be clamped upon opposite sides of the bearing pedestal 69 to the said squared shaft.

' Squared shaft 68 in turn is connected as by a suitable split clamp with the operating arm '72, it having a suitable quadrant 73 at its outer end provided with a series of holes for the attachment of a pipe clevis 74 threaded and clamped upon the upper end of an operating pipe or rod 76.; This operating. rod '76 at its lower end is connected with an arm '77, and it in turn is pivoted as by means of pin '78 on an operating quadrant 79 supported on a pivot 80. Pivot 80 is a pin mountedin the bracket 81. The bracket 81 is provided with locking hole 82 adapted to register with a hole in the lug 83 formed on the operating quadrant 79. 'A suitable pin slotted at its end to receive a padlock may be passed through the registering hole in the bracket and arm to lock the switch in closed position.

' The quadrant 79 has another hole 84 adapted to register with the hole 82 for locking the switch in open position. I

A handle member 86 is connected to quadrant 79 for the purpose of throwing the switch to open or closed position.

The insulator 63 has a cap 87 on which there is bolted a bracket 88, this bracket being bifurcated at its upper end to embrace the sides of'the contact bar 44, a pivot pin 89 being passed through the upper end of the bracket and through the contact arm 44.

The free end of the contact bar 44 is controlled by the movement of the bracket 88 about the squared shaft 68 as a center, and it will be seen that within the limits of motion indicated between the full lines in Fig. 1 and the dotted linesrtherein the outer end 43 of the arm 44 moves from a substantially horizontal position to a position which is more nearly vertical. The relation of, the lengths of the arms 62, 44 and the effective length of the bracket 88 are essential to secure this action. It will be observed that the bifurcated bracket 88 is split down to substantially the base thereof so that the end 43 of the arm 44 passes Within said bracket 88 when the switch is in open position as indicated in dotted lines in Fig. 1.

By changing the length of the link 62 or the effective length from the pivot 89 to pivot 68 of the operating insulator the contact portion 43 may be plunged below horizontal position or above horizontal position, but I prefer substantially the relation of the parts shown in the drawings whereby the contact portion 43 enters the stationary contact jaws 29 and 30 in substantially horizontal position.

The stationary arcing horn 86 shaped somewhat like a reversed numeral 4 has its stem 8'? secured by clamp 88 to the bracket 19. This arcing horn 86 extends sufficiently far forward to permit themovable arcing horn 90, which is fastened at the side of the bracket member 88 as shown in Fig. 1, to maintain contact as long as is necessary to protect-the current carrying contacts from injury by-any arc which may be formed upon opening up the switch.

Since the contact arm 44 which is relatively wide and heavy-is closely guidedbe tween the two arms of the bracket -88on the pivot8 9, a sing-le controlling link 62'is sufiicient to govern the path of the rear end of said-arm. 7

It will be observed that in the iormshown the stationary contact is disposed "a substantial.

link 62 is less thanthe length 'of the operating.

link whichincludes; the' bracket 88. The-length of the arm 44 'from its pivot6l to its front operating portion 43-is about the same as the length of the-link 62,-"and the' effective length between pivots 89 and61 while greaterv than the distance between the pivot 89 and the end of. the'contact 43 is less than the length of any of the other links or distance between operating. pivots. The distance between the pivot'pin l0 and 'center of shaft 68 in the form shown" is approximately the same as thelength of the controlling arm 62. While I have explained these dimensions and proportions'in connection with the specific form shown, it is to' be understood that variations between theseproportions are permissible where variations in action may betolerated, all without departing from the essential features of my invention. I

'The quadrilateral comprising'the' link 44, -link 42, a line drawn from'the stationary pivot 10 to the stationary pivot 68, and a line fromthe pivot 68 to the'pivot '89 constitutes what isin this patent application referred to as'quadrilateral linkage. 'In this quadrilateral linkage the line drawn from'the stationary pivot 10' to the stationary pivot 68 constitutes ie/fourth link which is of course-always stationary while'the other three links are movable.

When the switch is in open position'the rocking insulator 63 leans back toward the insulator 3 so that'the arcing-horn together "with the stationary arcing horn 86 provides divergent members suitable for breaking anarc if the same should persist by the natural riseof the arcon the horns. 1 1 t The striking distance between the live parts of the switch when the switch isopen is unusually high. This is secured'firstxby" the backward tilt of the insulator 63 when'the'switch is' open' and also by the disposal of the 'sleethood and its contained contacts vertically aboveithe' level of the insulator cap 8'7 so that the torward projection of the sleet hood and the contactsfltherein does notcut down the striking distance. The folding back of the switch arm 44 as'shown in dotted lines removes any projecting parts from the movable member, thereby assistingiinisecuring this maximum opening when the parts are thrown to the open position. o

When the rocking insulator is actuated to close the switch, the forward end 43 of the contact arm 44 moves along a path 90 to its full closed position. It is to be noted that the contact making portion of the switch arm approaches the housing 31 from below the housing and enters the housing by a substantially horizontal movement. As a result it is possible to provide a housing such as is shown at 31 having a top portion which is closed and having an open side through which the contact making portion of the blade passes into the housing.- ."Ihe top of the housing overhangs the open side thereof thereby protectingthe contacts againstth'e entrance of moisture or other foreign material from above. 5 This would not be possible if the contact making portion 43 were to move into engagement withthe contactin the I housing from a direction above the housingl 'The portion of the curve 90, which curve repre sents thepath of motion of the free end'of the contact making arm 43, that extends from a point slightly in'advanceof the housing upto the point on the curve representing the full closed position of the switch very nearly'appreaches the arc of a circle having a center at the point indicated at 91'. This'point 91 is, as

is tobenoted, directlywertically below the'c'on tact making arm 43 when the same is in its closed position. Hence, in so far as the contact making orbreaking action is concerned, the contact making portion 43 moves as though the insulator 63 were pivoted atthe point'9l with the contact arm 43'rigid with'the insulator. This is -a desirable type of motion and my improved linkmechanism provides this type of motion in a mannerby far superiorto the manner of obtaining this motion by using a largerrocking insulator pivoted at 91.

Whenthe switch is in the open position it is to be noted that the contact arm 43 lies between the times of the bifurcated bracket 88. Due to the fact that this bracket embraces the sides of the contact making portion 43of'the'switch arm there'is appreciably less chance of this portion becoming heavily coated with ice or sleet during the time that the switch remains in its open position, with the result that the switch can always be actuated toestablish good electrical connections with the contact within the housing 31, afeature which would not be possible if one or theother of the contacts'were heavily coated withiceor sleet. i

As previously pointed out, thelength of the "portion of the-link 44bet ween' the pivot pin 61 and the pivot pin 89 is less than the distance between the pivot pin 61 and the pivotpin 10. This is .of considerable importance during the switch opening operation. When the switch is in the position shown in dotted'lines in Figure 1, the rocking insulator. has approached its limit of permissible movement. Should an additional pull be exerted upon theoperating pipe '76 tend ing to further rock the rocking insulator in a clockwise direction as seen in Figurel this insulatorwill move further a slight amount whereuponrthe links 62 and 44 will'coine into a posi: tion ofisubstantial alignment. This position will be reached after a very slight turningof the rockingfinsulator from the position. as shown in the drawings. :After the rocking insulator reaches this position it is not possible to further turn the same since the links 62 .and 44 will hold the rocking insulator against further moveinent in a clockwisedirection; This. is of considerable importance from several points of view. In the first place it prevents the actuation of the switch to such'an. extentthat the rocking insulator 63 or the bracket 88 mounted thereon will be jammed against the stationary insulator 3. Such action might crack one or the other or both of the two insulators. In addition, should the operating mechanism break when the switch is in its open position, or should it .be necessary to remove the operating rod or any portion thereof, the rock-- ing insulator would not fall against the stationary insulator. If the links 44 and 62 were of diflerent proportions so that the link 44 is longer than the link 62 then the link-work would not tend to limit the swing of the rocking insulator and under such conditions this insulator might swing or fall against the stationary insulator 3 and it would certainly render the reassemblage of the operating mechanism including the clevis 74 and the pipeor rod 76, or any of the lower operating parts that have been disassembled, more diflicult due to thefact that in the final assembly the operator would have to be supporting the rocking insulator as he is assembling the parts. This difllculty is aggravated by the fact that switches of the kind here contemplated are generally gang operated there being three or more such switchesmounted on a common shaft and it is the weight of all of these switches that would have to be supported by the operator in the flnal reassembly of the apparatus.

I claim: 7 1. In combination a bracket member having a base for mounting the same upon an insulator, a sloping side wall, a sleet hood mounted upon the upper end of the same, a pair of contact jaws mounted inthe sleet hood having flexible leads extending down into engagement with said sloping member, a terminal lug having a flattened portion clamped upon said flexible leads against said sloping member. i

2. In combination a bracket member having a base for mounting the same upon an insulator,

a sloping side wall, a sleet hood mountedupon the upper end of the same, a pair of contact jaws mounted in the sleet hood having flexible leads extending down into engagement with said sloping member, a terminal lug having a flattened portion clamped upon said flexible leads against said sloping member, a laterally extending strain arm, and clamping means for a line conductor on said strain arm, said terminal lug having a tubular socket in alinement with said clamping means.

3. In a switch, a bracket having a sloping clamping member, contacts mounted on the upper end of the bracket, and having flexible leads extending into, engagement with said sloping member, and a terminal member having a flattened portion engaging said flexible leads and clamped to the sloping member.

4. In an electric switch, the combination with a rocking insulator mounted on a fixed pivot,

means for rocking the insulator, a bifurcated bracket mounted on the insulator, a switch blade pivotally connected to said bracket betweenthe arms thereof to swing in the same plane as'the insulator, and link means for swinging the blade about its pivot upon the opening movement of the insulator into a position between its pivot and the insulator, the contacting end of the blade lying between the arms of the bracket, the blade being moved into a position such that the striking distance to the blade is approximately the same as the striking distance to'the bracket.

5. A disconnect switch comprising a supporting insulator, a contact mounted thereon, a rocking insulator mounted adjacent the first named insulator and rockable towards and away from the same, a bifurcated bracket mounted on the rocking insulator, a switch arm pivotally mounted on the bracket and closely guided between the arms thereof and including a contact making portion movable into and out of engagement with the contact upon movement of the rocking insulator, and means effective as the rocking insulator moves towards its switch open position to swing substantially the entire contact making portion of the switch arm into a position between the closely guiding arms of the bracket.

6. In an electric switch, in combination, a movable contact member including a contact making' portion, means for shielding the foremost portion of the sides of said contact making portion from sleet when the contact is in its switchopen position, said means comprising contact supporting means, and means for moving said contact making portion out of said shielding means when said contact member moves to its switch-closed position. I

'7. In an electric switch, in combination, a supporting base, a bifurcated link pivoted on said base, a contact member including a contact making portion pivoted on said link, said contact making portion being adapted to fit closely between the arms of said link, and means effective as said link and contact member move into their switch-open position to swing the foremost end of said contact making portion into a position between the arms ofsaid link.

8; In an electric switch, a movable contact making member including a contact making portion, a second contactmember with which said contact making portion engages in its switch closedposition, means for shielding said second contact member from sleet, means for supporting and shielding said contact making portion from sleet when said contact making portion is in its switch-open position, said last means including means shielding the contacting tip of the contact making portion, andmeans for moving said contact makingportion into sleet shielded relation with said supporting means when said contact making portion moves to its switch-open position. v

9. Inan electric disconnect switch, in combination, a stationary contact, a sleet hood enclosing the contact and having a side opening, the top .01 said hood overhanging the contact, a movable switch arm including a'contact making portion adapted to be plunged beneath the overhanging "top in a substantially horizontal direction into engagement with the contact'to close the switch,.and means for imparting said plunger movement to the switch arm, said means comprising a quadrilateral linkage including a part of the switcharm and a bifurcated link pivoted to, said switch arm, said switch arm and link being so arranged as to swing the foremost end of said contact making portion into sleet shielded position. between the arms of said link whensaid switch arm moves to its-switch-open position.

ERNEST H. JACOBS.

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