US2203863A - Electric switch - Google Patents

Description

June 11, 1940. F, FARRELL 2,203,863

, ELECTRIC SWITCH Filed April 28, 1937 2 Sheets-Sheet 1 ornelj.

June ll, 1940. F, FARRELL 2,203,863

ELECTRIC SWITCH Filed April 28, 1937 2 Sheets-Sheet 2 Wed Effe/ Patented June 1l, 1940 PATENT OFFICE ELECTRIC SWITCH Fred Farrell, Elmwood Park, Ill., assigner to Electrical Engineers Equipment Company, a

corporation of Illinois Application April Z8, 1937, Serial No. 139,405

1? Claims.

The present invention relates to electric switches of the type wherein the contacts have a substantially rectilinear movement into and out oi their circuit closing positions. A switch of this type is disclosed in my prior United States Patent No. 1,918,901, granted July 18, 1933. The present invention is an improvement upon the invention disclosed in said prior patent.

The principal object of the present invention is to provide a switch of the type mentioned with certain modied electric connections and with modifications in structure which suit .it to additional conditions of service. Another object is to provide a switch which shall be eflicient and sat- 3 isfactory in operation while being at the same time simple in construction and economical to manufacture.

In carrying out my invention I preferably provide a switch structure wherein the cooperating contacts are located along a rectilinear axis and one of said contacts, at least, is movable along said axis into its different operative positions. Preferably, too, the contacts, or some of them, are located within insulating members which ordinarily partake of the relative movements ci the switch contacts. These members preferably take the' iorm of insulating tubes arranged in telescopic relation to each other. Novel toggle mechanism also serves to lock movable parts of the switch, which are adapted to occupy an elevated position, so that they cannot drop and thus accidentally close circuit as might occur were the locking toggle not provided. Preferably, too, the movable switch element is reciprocative along guides which are insulated, or composed of insulating material. By the use of such insulatingr guides, the dimensions of the switch for any given capacity may be considerably reduced over those forms wherein such insulation is not provided and air alone is relied upon as the dielectric.

The switch may be made up in any number of units by simply associating the units side by side upon a suitable frame.

The switch disclosed herein is especially useful a disconnect switch. However, it need not bc limited to that service.

. The switch of the present invention is particularly useful in power systems in which it is adapted to carry heavy currents. It may be employed as a disconnect or isolator for breaking the continuity ci the electrical circuit. In conjunction therewith the line which is disconnected from power may be grounded. The arrangement is such as to give substantially complete weather protection and yet give a visual indication of the open position when the operating connecting plunger is moved into engagement with the grounding contact and vice versa, when the plunger is in circuit closing position. Obviously, for indoor use the overlapping of the insulators with the sleeve need not be employed as weather protection is not necessary.

By changing the connections of the various contacts, the connecting plunger may be employed to ground either one of two lines or to ground them simultaneously if desired. The switch may also be employed to make a changeover of the line from one source of current to another without interruption or the transfer may be made with interruption of one line in advance of transfer to the other. Similarly, the two lines may be connected simultaneously or separately to `a common supply connection.

One of the most important practical advantages of the present switch is the ability to make any of the above connections in a compact device which require-s a minimum of space. This switch can be installed in situations which would not allow the installation of other forms of switches. It can be mounted -directly in the run of the conductors and upon a grounded or insulated support. It will go into spaces and operate satisfactorily where no other form of switch can be used.

In addition to its compactness, it is substantially completely weatherproof.

An important operating characteristic resides in the use of a self-locking toggle for holding the contacts in the normal `current conducting position. As will be described later, the preferred form of main contacts which are employed for continuously conducting heavy current when the switch is closed and hence should have minimum resistance, are of the type which are held in engagement under pressure which exerts a resilient reaction against the operating mechanism. This permits of a certain tolerance in the difference in position oi the movable contacts relative to the stationary contacts and a certain permissible inequality between the contact-s of either group, so that all three may be brought into 'contact and held resiliently in engagement even though they are slightly out of adjustment relative to the other group or even relative to each other. By the use of the toggle arrangement, these spring pressed contacts are held and locked iirmly together, giving a reliable contact which requires minimum attention.

The various features and advantages of the invention will be more fully understood upon reference to the following detailed description taken in connection with the accompanying drawings wherein preferred embodiments of the invention suited to single-phase and multi-phase circuits are shown.

In said drawings, Fig. 1 is a side elevation of a single-phase switch unit constructed and arranged in accordance with the present invention. Fig. 2 is a central vertical section through the same, the section being taken on a plane indicated by the line 2-2 of Fig. l. Fig. 3 is a front elevation of three units mounted upon a single frame with suitable actuating mechanism thus providing a switch for a three-phase circuit. Fig. 4 is a central vertical section, similar to the central portion of Fig. 2, illustrating a modified construction wherein the intervening reciprocating contact bridges the circuit between the associated contacts when moving from one eXtreme position to the other. Fig. 5 is a similar section of the upper portion of a further modified structure. And Fig. 6 is a central vertical section through the lowermost contact mounted upon the frame with a suitable intervening insulator, this structure being a modication of the lowermost structure of Fig. 1. Throughout these views like characters refer to like parts.

Referring to said drawings in detail, and at first more particularly to the single-phase structure of Figs. l and 2, ID designates an upper insulating member which takes the form of a socket or tube having an open lower end. This tubular member I0 cooperates with an interme diate insulating member II which also is preferably tubular in form. In turn the member II cooperates with a lower insulating tube I2. These tubes all have a common longitudinal axis, as will be apparent from a consideration of Fig. 2. Within these tubes, respectively, are an upper electric contact I3, an intermediate electric contact I4, and a lower electric contact I5. Below the contact I5 is an additional electric contact I6. These contacts are all in axial alignment. The three principal contacts of the switch are the contacts I3, I4 and IE. The contact I5 is auxiliary and is such as to provide connection with the intermediate contact I4, as will be apparent from the description hereinafter given. Between the contacts I5 and I6 and surrounding the space occupied or to be occupied by the contact I4, is an insulating tube I1. Ordinarily the tubes I0, EI .and I2 are composed of porcelain while the tube I1 is composed of Bakelite or other suitable insulating material.

The three tubes IQ, II and I2 are mounted, respectively, in three frame members i3, I9 and 23. The insulating tube I1 is secured, as will be more fully pointed out hereinafter, to the lower end of the contact i5. As shown, the lower end of the tube I1 closely approaches the upper end of the Contact I. The contact I6 is in turn mounted upon a frame member 2l. The frame members I8, 2D and 2% are relatively Xed while the frame member I9 carrying the intermediate insulating member II is movable. As clearly shown, the tubular insulating members I S, II and I2 are in telescopic relation to each other, the upper member I5 being of largest diameter, the intermediate member II or" intermediate diameter, and the lower member I2 of smallest diameter. These tubes, as clearly shown, are aligned and in their telescopic operation the intermediate tube II passes into the upper tube II! and the lower tube I2 passes into the intermediate tube II. The reciprocating parts are made smooth and provided with sufficient clearance to prevent their engaging with each other when moved as described. The non-overlapping parts of the tubes have their outer surfaces preferably corrugated or otherwise formed so as to provide a superficial surface of greater length in order to increase the resistance to creepage losses of current over the surface of the tubes as is well known in the electric insulator art. As clearly shown, the insulating member I0 has the outer corrugated surface 23 and the tube I2 has a similar outer corrugated surface 24. In the former case the corrugations are al1 above the frame I8 and in the latter case they are all below the frame 20. The intermediate tube II does not have an outer corrugated surface but the latter is smooth so as to readily pass upward into the upper tube I0.

The main frame which carries the frame members I8, 20 and 2I, includes, for the single-phase structure, two end frames 25 which are provided with upper flanges 21, lower flanges 28 and rear fianges 29. The latter are provided with bosses 3D in which are openings 3I for the passage of retaining bolts or other means for securing the frame against a vertical wall or like support.

Extending between the end frames 25 and at the top of the same, are transverse frame members 32 located one at the front and the other at the back of the end frames. The members 32 preferably take the form of angle irons and are secured to the upper flanges 21 of the end frames by suitable bolts 33 and nuts 34, the bolts passing through apertures provided in the associated fianges. Similarly, the lower fianges 28 of the end frames are provided with frame members 35. Again, these members take the form of angle irons and. one is located at the forward edge of the frames and the other toward the rear. In this instance, suitable bolts 35 and associated nuts 31, the bolts passing through the flanges of the associated members, secure the parts together. The lower portion of the frame is provided by rods 38 which depend from the frame members 35 and support the structure which carries the lower Contact frame member 2I. The upper ends of the rods 38, of which there are four, are secured to fianges of the frame members 35, preferably by passing the same through apertures in the flanges and securing them in place by suitable nuts 39. At the lower end of the rods 38 there are end frame members 40 cooperating with the member 2I. The latter in the embodiment illustrated is a plate. The members 4U preferably are angle irons. These angle irons 40 are connected to the plate 2 I, in the embodiment illustrated, by passing the rods 38 through apertures in the plate 2I and registering apertures in the horizontal flanges of the angle irons 40 and then securing the same in final position by tightening up the nuts 42 upon the rods. In this way a support is provided for the lower contact I6.

The insulating tube I0 may be secured within the frame member I8 in any suitable way. In the present instance this frame member has an opening through it which loosely fits over the outside of the tube I0 below the corrugations 23. When the tube is properly positioned in the frame i8, a filling of cement 5I serves to bind the parts together and hold the tube Xed within the frame I8 and in proper alignment with the axis of the structure. The tube I I is similarly secured to the intermediate frame IS by a similar filling 52. The frame I9 has a ring portion 53 which fits loosely over the exterior of the tube II and is secured by the cement. The ring 53 is provided with lateral horizontal portions 54 which lie in a common plane and overlap portions of two transverse frame members 55, one located at the front of the structure and the other at the rear. These members 55 are preferably angle irons and the flat portions 54 or theirame IS overlie the horizontal flanges of the angle irons and the parts are' secured 'together' by suitable bolts 56 and nuts 51. As pointed out more fully hereinafter the frame member I9 and the associated members 55 constitute a movable frame for raising and lowering the intermediate insulating tube I I and the parts fixed to it. In like manner the lower insu lating member I2 is secured by suitable cement 58 to a ring 5B forming part of the frame member 20. As clearly shown the insulating tubes are carefully aligned so that they may be telescoped by a simple to and fro movement of the central or intermediate frame and tube.

Each tubo of the three mentioned has an elec-n tric contact associated with it and the parts are constructed so that the contacts may be secured to the respective insulating members. Thus in the case of the tube lli the tube has a transverse portion Bil which in the present instance constitutes the end of the tube. This end 60 is apertured for the passage o1 the contact I3. A suitable cement filling I secures the contact in place when the parts are properly assembled. Thus in the case of the contact I3 there is a shank 62 and. a head The head is adapted to engage the inner face of the end Bil of the insulating tube II! and a nurJ @Il screwed upon the outer threaded end of the shank S2 is used to clamp the Contact to the head. Ordinarily a suitable washer 55 is located between the nuts 64 and the adjacent head il@ and a similar washer 66 is located between the head (5S and the inner wall of the end Fill. It will be clear that when the parts are assembled and the nut Fill screwed down tight then the contact will be properly placed. The outer end oi the shank E2 also carries a nut 61. Between the nuts il and @4I the apertured end of a wire terminal t8 may be located. When the nut el is screwed down tight then the terminal is properly held in place and is in good electrical engagement with the contact I3.

When it comes to the intermediate contact I4 secured to the tube li, then an inward project ing ring 'ill formed upon the inside of the tube I I cooperates witli a head ll which forms the head of the intermediate contact U.. The head 'Il is provided with a ring i2* which is adapted toy lie above the insulating ring ld. A nut 'i3 screwed on the lower portion of the head 'II cooperates with the other parts in securing the head to the insulating member. In this case intervening '.14 and 'l5 are used to cushion the contacts between the metal iiange 'I2 and the metal nut T3 in their action upon the intervening porcelain iiange lil. At this point it may be noted that the head ii is apertured and the aperture is threaded for the reception of the rod which oonstitutes the main element oi the contact I4.

When it to the lowermost contact I6 the same is hold in place by nuts 'i6 which are threaded upon the exterior' of the contact and engaged with the frame plate 2i on the one hand and with terminal conductor bar l'l on the other hand. By tightening up the nuts 'it firm contact is made between the parts and current passing into the tubular contact i5 will pass to the other metal parts associated with it and particularly to the bar 71. As will be apparent later this terminal may be differently mounted. As here mounted it is in permanent mechanical and electrical engagement with the lower end of the frame of the switch. In some instances it may be desirable to insulate this contact as will be pointed out later.

t may be noted also that the upper end of the insulating tube II might be shaped somewhat differently. A modification in this respect is also referred to later on. In the structure before us in the later modified structure the action of the intermediate tube- II and the contact I4 which it carries when cooperating with the contact I3 and the tube Ill is that of a plug and socket. The lower elements constitute the plug and the other elements the socket.

When. it comes to the form of the contacts which are carried within the different insulators, different contact arrangements may be employed.

In the present instance there are cooperating ele- 'l ments on the head of the upper contact I3 and the head oi the intermediate contact I4 and the latter which is in the form of a solid rod cooperates with a tubular Contact at its lower end. In my aforesaid Patent No. 1,918,901 this arrangement is employed and this might obviously be used in the present case with slight modications in structure to adapt the central tubular contact to the solid end contacts. But considering the structure disclosed in the form` ci the invention now under consideration it will be seen that the upper contact I3 has upon its head t3 two rows of spring iingers, an inner row 'I8 and an outer row la. These fingers are preferably provided by cutting away the head 23 on. its under side so as to provide concentric spaces and then slitting resulting projections by longitudinal cuts so as to give the several lingers as shown and described. These fingers are also preferably curved so as to provide a bell-mouthed. approach. A coiled outer spring 8i! extends around the outer lingers '13 and tends to force them inward. A coiled. expanding spring 8| extends helically around within the space behind the lingers 'I8 and engages the surfaces oi these iingers and by its action tends to force them outward. The spring pressed fingers '58, 19, however, are sufficiently stiff, while yet laterally yielding, to provide the requisite space between them for the entrance oi a cooperating ring B2 located upon the head 'll ol the intermediate contact I4.

The ring 32 is in.` cross` section shaped with outer and inner curved surfaces somewhat re*- semblng the curves of a gear tooth. This ring, by reason oi the curvature of its surfaces, readily enters into the space between the Fingers i8 and I9 to make contact.

It will be apparent that when the intermediate contact Ul is in its uppermost position goed elec trical connection will be made between the heads 63 and 'Il through the cooperating ring g2 and the associated contact fingers "f8 and '59. When he contact lil is moved downward. then the circuit between the contacts I3 and ifi will be opened and any arc which may be formed between the contacts will be in a chamber formed inside of the tube IEl and bounded beneath by the receding insulating tube l i Such a chamber will have access to the outside air through a .narrow passage 3 formed between the tubes la and I l. This passage materially assists in extinguishing any arc as pointed out in my aforesaid patent.

When the contact I4 is moved to its lowermost position its lower end will pass into the tubular Contact iii. This contact like the others is coinposed of copper or other good electric conducting material. .In order to make closey engagement with the end ol the rod of contact I4 the upper ends ol the tube IIS are slitted so as to provide yielding fingers 84. These iingers are pressed inward by coiled springs positioned in suitable depressions on the outer surfaces of the iingers 84 and acting thereupon the same as the coiled spring Sli upon the associated iingers '|9. Obviously when the intermediate Contact I4 is in its lowcrmost position it will make circuit only with 'ie lowcrmost contact i5 and the auxiliary contact Coming now to the additional contact I wc have a feature which distinguished the present invention from the prior art. This contact is also made up in the form of a tube having its upper end slitted so as to provide a series of spring 1ingers 90. These lingers are, like the 'lingers 'I9 and 84, spring pressed inward so as to provide good electrical contact with the rod of the intermediate contact Id. The coiled springs 9| which rest in depressions formed on the outer surfaces oi" the ngers 93 serve to bring about this good electrical contact, the operation being the same as in the case of the previously mentioned springs 80 and 85. The tubular contact I5 is located Within the insulating tube I2 and is coaxial with the same and with. the contact III. rEhe tube I2 is provided with an inner ring 92 which extends a short dis-- tance in from the wall oi the tube. Cooperating with this ring is a flange 93 extending outward from the tubular contact I5. Between the ring 92 and flange 93 is a piece of rubber or like insulation 94 which serves to take up unevenness when the parts are drawn together to keep them in position. The accomplishment of this result is brought about by a nut 95 which is threaded onto the exterior of the tubular contact I5 near its lower end. Suitable cushioning material 96 between the upper face of the nuts 95 and the lower end of the insulating tube I2 takes care of unevenness in the parts which are drawn together. When the contact I5 is dropped into the open end of the tube I2 the flanges 92 and 93 come into action and the contact is brought to a stop in its proper location in the tube. Then when the nut 95 is applied it will rmly press against the lower end of the tube I2 and thus secure the tubular contact I5 in place within the insulating tube I2.

It now remains to connect up the contact I5 with a suitable outside terminal. This may be done in different ways. In the present instance a bar 9i is apertured so as to pass over the lower .l end of the tube I5 and this bar is pressed upward into iirm engagement with the nut 95 by means of a nut 98. When this is accomplished the bar 91 is in goed electrical contact with the contact member I5. As shown, the bar 9'I may be connected with any suitable conductor, such as the conductor 99.

In this connection it may be noted that the insulating tube i'l, which forms in a way an extension of the tube I2, is interiorly threaded so as to be screwed upon the lower end of the tubular contact I5. In this way the space between the lower end of the contact I5 and the upper end of the contact IG is practically surrounded by an insulating material.

With the construction described it will be clear that the rod of the intermediate conductor I4 is always in engagement with the Contact I5 and hence with the terminal bar 91. Thus the switch structure is provided with three terminal contacts, viz., the contacts I3, I5 (by way of 9T) and I6. Obviously a switch of this structure may be variously connected. Indeed, there are so many possibilities in this connection that it seems needless to point out any particular ones. In some instances the contacts I3 and I6 may be connected to sources of electrical energy and the contact I5 may be connected with devices which are to be supplied from either of said sources, at one time from one and at another time from another. Again, the contacts normally in use during the active operation of the apparatus may be contacts I3 and I5 while the contacts I6 may be one connected to ground. In such case the breaking of circuit between the contacts I3 and I4 may be accompanied by connecting certain of the apparatus through contacts I 5 and These are merely suggestive uses.

In order to guide the intermediate tube II and its contained contact I4 in a truly rectilinear path I preferably provide guide rods |00 which are fixed in the frame of the switch. These rods are parallel to each other and to the axis upon which the several switch contacts are located. In the present instance each rod |00 extends between a flange IOI formed on the associated end member and the upper Iiange 2'I of said end member. Suitable retaining nuts |02 and |03 threaded upon the lower end of the rod serve to firmly secure the rod |00 to the flange IOI. A head or nut |04 at the opposite end of the rod |09 bears downward upon the flange 2`| of the end member and serves to hold that end of the rod in place. Before the rod is put into place in the structure an insulating tube |05 is slipped over the same. This sleeve or tube bears at its upper end against the under surface of the ange 2'I and toward the lower' end of the rod |00 has bearing against it a nut |96 which is threaded upon the rod and when turned up tight forces the tube |05 up against the flange 27 and thus iirmly holds the tube in place upon the rod. A lock nut I0'I may be used upon the rod to maintain the insulating tube in its position. On the outside of the insulating tube the sleeve |08 of the reciprocating frame I9 travels. This sleeve is secured to or forms part of the structure of the movable frame.

As shown there are two guide rods |00 with their insulating coverings |05 and there are likewise two cooperating sleeves |08. As a result of this construction the intermediate Contact I4 is given proper reciprocations.

It will be seen that the reciprocations thus given to the intermediate portion of the switch will be in a right line. Thus contacts I3 and I4 will readily intert when making and breaking circuit and likewise the lower end of the contact Il'. and contact I6 will readily telescope when circuit is to be made or broken at that point. Of course, at all points in the travel of the intermediate contact I4, the latter will be in electrical engagement with contact I5.

For the purpose of actuating the intermediate frame I9 and its associated parts, certain toggle mechanism is employed. As shown, the intermediate frame I9 has at its ends upturned flanges III and these provide supports for laterally projecting pins I I2 which serve as pivot pins for toggle member I3. As clearly shown, the members I|3 in each instance are apertured near their upper ends for the passage of the pivot pins II2. Each toggle member I I3 at its lower end is apertured for the passage of a pin I I5. This is also a pivot pin and unites the lower end of the link |I3 to the upper end of the toggle member IIS which is in the case of both toggles mounted upon a I6 to ground.

shaft ||1 suitably journaled at its ends in bearings formed in the end members 25. When the parts are in the position shown in Fig. 1 the toggle is just beyond dead center and the toggle member II3 engages a stop II8 upon the adjacent flange III of the reciprocating frame I9.

It will be seen that when the toggle is in this beyond-center position and in engagement with the stop II8 the frame I9 is held up with contacts I 3 and M closed. Because of the position of the toggles at this time these contacts are located in engagement and it is obvious from the inspection of the toggles that the same is true. Because of this locking of the contacts by the toggles any Workman having to do With the installation or the operation of the switch at any time can at once determine its electrical condition and therefore is in no danger of injury by reason of having to do With apparatus which he thought was in one condition when it was in fact in a diierent condition.

The toggle mechanism may be operated in diiferent ways and may be variously controlled but since such forms no part of the present invention it will be needless to point out any mechanism of this kind. Suiiice it to say that the end of the shaft III is squared as shown at ||9 so as to receive the socket of a crank which may be used to throw the switch manually. In practice additional precautions may be taken and if desired the actuating arm of the switch may be locked as indicated in my prior Patent No. 1,918,901.

As previously stated a number of units such as described may be used according to the requirements of the circuit. It is only necessary to place the elements side by side upon suitable frame Work to build up a switch of any desired number of units. By Way of illustration I have shown in Fig. 3 a switch of the same construction as that heretofore described but diiering only in that three of the units are mounted in the frame structure. Thus a three-phase switch is produced. When the number ci units is increased then of course certain elements of the structure must be modified. Thus with the three units the upper insulating tubes III have their frames I8 secured to the front and rear frame members 32a.. Since the frame must be longer in order to accommodate three insulators IB it is necessary to replace the former frame members 32 by the longer frame members 32a.. Similarly, the intermediate frame members 55 are replaced by the longer frame members 55a. Again, the frame members 35 associated with the insulating tubes I2 give way to the longer members 35a. Similarly the members 40 are replaced by the members 40a and the shaft III is replaced by the longer shaft II'Ia. In other respects the switch is practically the same and by reason of the full description heretofore given it seems unnecessary to go into the description of the three-phase switch with any greater particularity.

Obviously the circuit arrangement heretofore described may be variously modified in addition to the modification suggested by my prior Patent No, 1,918,901. Thus in certain switch structures it may be desirable to cause the extreme contacts to be brought into electrical communication with each other during the operation of passing from one extreme electrical condition to another. A Circuit arrangement to accomplish this result is indicated in Fig. 4. As there shown the upper insulating tube IU isassociated with the modied insulating tube IIa and a modified insulating tube I2a. The tube I'I also gives way to a tube |10; of slightly larger diameter. This increase of diameter is necessary because of the projection of the contact IIia of greater length than the contact I6 into the interior of the tube I'Ia. The several tubes I Il, Ila, I2@ and I 'la are mounted practically as the corresponding parts IIB, II, I2 and Il, respectively, heretofore described. In this arrangement the contacts i3d, Illa and IBa diiier from the corresponding contacts I3, I4 and I6, respectively. The contact I5 remains the same.

The arrangement shown in Fig. 4 merely has the dimensions changed over the previous form oi the invention in order to insure that the contact Ist-a when moving from its uppermost position to its lowermost position will bridge contacts lila and Ia. The contact |40. is shown in Fig, 4 in full lines. T'he position so shown is the uppermost position of the contact Illa, and its limits are designated a, a. Likewise the limits of the contact Ilia in its intermediate or bridging position are shown by the dash lines b, o. Likewise the limits of the same contact in its lowermost position are shown by the dot and dash lines c, c.

The contact i3d is tubular in form. It has the same shank 62 as is present in the contact I3 but its contacting end is tubular and slitted so as to provide a number of fingers |20 held in spring pressing condition by the outside coiled springs IZI. The shank is held in position in the end 6I! of the member I0 through the action of the nut 6d and an additional nut |22 Which takes the place of the head 63 of the former construction. By tightening up the nuts 6l and |22 against the intervening cushions 65 and 6B the terminal contact I3 may be held rmly in place. Obviously it is in alignment with the axis of the switch and in position to have its fingers |20 engaged by the upper end of the reciprocating contact Illa.

The Contact Illa is in this instance a rod of suitable conducting material which has enlargement |23 at a point near its upper end, which enlargement is threaded exteriorly for the reception of a nut |24. This nut cooperates with a nut |25 and suitable intervening cushions 14, 'I5 to secure the contact Ida to the tube IIa. The nuts |24 and |25 act upon the ange 'I0 on the inner side of the tube IIa just as in the case of the preferred embodiment more fully described heretofore. In this instance the tube IIa is secured to the reciprocating frame in the same manner as heretofore described.

When it comes to the insulating tube |2ct we have the same flange 92 as before and the same ange 93 upon the tubular contact I5 cooperates with the same nut to secure the parts together. Again, there are cushions 514 and 96 located and operating as in the previous case. In this instance too the same conducting bar 91 isheld in contact with the nut 95 by a nut 98. The tubular insulating extension Via is also threaded onto the outside of the Contact I5 as was the tube I'I in the prior construction. The tube Ila. is, however, of larger interior diameter since it must accommodate the tubular contact I Sia with its contact fingers 84a and their exterior coiled springs 85. The tubular contact IIa is secured to the frame parts just as the contacts I6 heretofore considered.

As previously indicated the intermediate tubular insulating member II need not be made in the form shown in the earlier figures of the drawings but may be modiiied so that the contact which it carries will extend beyond the end of the insulating tube instead of terminating at a point inward from its end as illustrated in Fig. l. Such a modication oi this portion of the structure is illustrated in Fig. 5. As there shown the insulating tube |U and |2 are the same as heretofore described. The intermediate tube, however, is modified as shown. The petticoat of' the insulator ||b terminates at its upper end in an inwardly extending iiange |26 which cooperates with the nuts |24 and |25 in rmly securing the tubular insulator ||b to the intermediate contact |4b. The contact |41) is in general the saine as the contact |4a but is shorter. It has an enlarged portion |23 that is threaded on its outer surface for the reception of the nut |24. The contact |4b, however, is made of a length suited to the requirements of the upper contact |3b.

As clearly shown the upper contact |313 has a shank 62 with associated nuts 54 and |22 which with intervening cushions 65 and 66 cooperate in the same way as the corresponding parts in Fig. 4 in securing the contact |3b to the insulator I0. The contact |3b is provided at its lower end with a series of fingers |21 similar to the fingers |20 of Fig. 4 and these fingers are pressed inward by a coiled spring |28 which rests in depressions on the outer faces of the iingers. The fingers |27 are also curved outward and downward so as to provide a bell-mouth opening for the upper end of the intermediate contact |413.

With this construction the contact |4b with its insulator Hb is somewhat more plug-like in appearance than the intermediate contacts of the other figures. The action, however, when the parts are moved to and fro, is the same in making and breaking circuit as before described, except that with the insulating member ||b providing a short annular passage |29 to atmosphere, the chamber in which the circuit is broken is more quickly opened directly to atmosphere through a wide opening. In the earlier figures the petticoats of the two insulators overlap to such an extent that considerable movement is required before the narrow outlet passage 83 is ineffective. The relation between the tubular insulators ||b and |2, however, continues about as it does between the corresponding parts in the other iigures.

Turning now to a consideration of the lowermost contact it will be noted that the same may be mounted in an insulator and have a connection which is separate and distinct from the frame of the switch. Such a contact is illustrated in Fig. 6. There the contact designated |6b is made up of a tubular portion |34 and a headed stem |35. The insulator itself designated |36 is composed of porcelain or other suitable insulating material and is secured to the lower frame members 2| and 1'1 by suitable cement |31 interposed between the interior of the walls of the opening in the metal pieces 2| and 11 and the outer wall of the insulator just above the corrugations |38. The manner of attaching the insulator |36 to its frame is the same as that employed in attaching the insulator I0 to its frame. As shown the insulator |36 has a head |39 which is apertured for the passage of the shank |35 of the contact |61). The shank is threaded and secured in place by the nut |40. The upper end of the shank has a shoulder |41 which cooperates with the nut |40 in securing the contactin place in the insulator". The nut |42 is used to hold an intervening terminal |43. When the nut |42 is screwed down tight upon the shank |35 the terminal |43 is iirmly held in place and connection is established with the tubular portion |34 of the contact IGb.

The interior of the lower tubular portion |34 of the contact |6b is threaded upon the upper end headed portion |44. The downward movement of the tube |34 upon the head |44 is limited by a shoulder |45 upon a tube |34 engaging the upper edge of the head |44. The upper end of the tube has flaring ngers |46 made up as heretofore described and these are held in place by coiled tension springs |41 bearing suitable recesses in the outer surfaces oi the ngers |46. It will be noted that where the lower contact is insulated as shown in Fig, 6 the frame will be free from connection with this contact.

When considering the several contacts in the different forms it will be noted that these contacts are positioned along a linear axis. It will also be noted that although this axis is vertical in the drawings the switch itself may be positioned in various ways in all of which the axis would not be vertical but would occupy some other relation to the horizon. For convenience in designating the various contacts, and particularly in the claims, the contact |3 and those corresponding to it may be called first contact, the contact I4 and those corresponding to it, the second contact. The contact I6 and those corresponding to it, the third Contact, and the contact I5, and those corresponding to it, an electric terminal. forms shown is in constant electrical engagement with the second contact but obviously the latter might be interrupted by non-conducting portions for certain purposes necessitated by the particular circuits for which the switch was used. In such case the terminal I5 might be out of circuit when engaging such insulating portions and would be if such portions were extensive enough to wholly insulate the terminal l5.

From the modications indicated it will be apparent that changes may be made in the vari- A contact having an insulated line terminal comprising means for clamping and supporting the end of a line conductor, a stationary intermediate insulated line terminal, a stationary insulated lower contact, rigid supporting insulators for said line terminals, an axially movable elongated rodlike conductor in constant slidable electrical engagement with said intermediate terminal and adapted to engage selectively either of said contacts, a tubular insulator connected to said movable conductor and telescoping with said supporting insulators to render the switch weatherproof, means for guiding said elongated conductor independently of the contacts, a movable rocking shaft for reciprocating .said elongated conductor, a rigid arm connected to said shaft and a link for connecting the arm and the tubular insulator, said arm and link forming a toggle when the conductor is moved into engagement with the upper contact to lock the conductor and said upper contact together.

The latter in all the 2. In a heavy amperage high tension disconnect switch, a pair of spaced aligned contacts insulated from ground, a plunger movable into and out of engagement with said contacts one at a time, a stationary sleeve contact embracing said plunger, said sleeve having line terminal for making connection between the plunger and a line conductor, insulating sleeves for the plunger and the sleeve contact and guiding means insulated from but mechanically rigid with the plung. er for guiding the plunger independently of the insulating sleeves.

3. In a high tension switch of' the class described, a metallic frame member provided with an upper a lower and an intermediate shelf, an inverted cup shaped insulator rigidly mounted on the upper shelf and opening downwardly ben low the shelf, a stationary contact in cup and having a line terminal supported by the cup above the shelf, said contact facing the open end of the cup, an insulating sleeve mounted in said intermediate shelf and extending partly above and partly below the same, a condo ting plunger disposed in said sleeve, a second line terminal supported on said insulating sleeve, means lor maintaining electrical connection between said second line terminal and said plunger, an insulating sleeve fastened to said plunger, last named sleeve telescoping internally with the cup shaped insulators and externally with said first named sleeve, and a contact supported on said lower shelf and being engageable by said plunger when the same is moved downwardly.

4. The switch of claim 3 wherein a stationary metallic contact sleeve embracing said. plunger is mounted on said insulating sleeve to maintain connection between said plunger and said intermediate terminal.

5. In a high tension switch, a frame having a pair of shelf members one above the other, an open ended insulating sleeve mounted on the upper shelf' and extending through the saine, an axially movable plunger reciprocable in said insulating sleeve, a metallic sleeve mounted on the lower end of said insulating sleeve and projecting up within said insulating sleeve, said metallic sleeve having spring iingers slidably engaging said plunger, a terminal connected to said metallic sleeve, a contact mounted on said lower shelf, said latter contact being engageable by said plunger.

6. The switch of claim 5 with a tubular .insulating sleeve carried by the lower end of the metallic sleeve and extending to a point adjacent the contact on said lower shelf.

7. The switch of claim 5 with a telescopic insulator mounted on the plunger and cooperat ing with the insulating sleeve, means secured to said telescopic insulator and guided on the frame for operating said plunger..

8. In a switch, a frame member having an upper shelf, an intermediate shelf and a lower shelf, an insulated stationary Contact mounted on the upper shelf and having a line terminal, a tubular telescopic contact mounted on the intermediate shelf and having a line terminal, a lower stationary contact mounted on the lower shelf, a rodlike telescopic contact slidalole endwise in the tubular contact and engageabie with the insulated contact and with the lower contact, a movable slide insulated from but mechanically connected to the rodlike contact and guided on the frame member, and means for shifting the slide to move the telescopic rodlike contact to engage and disengage at least one of the stationary contacts.

9. The combination of claim 8 wherein the rodlike contact and one of the stationary contacts are held in. engagement under yielding re silient pressure, and said means comprises a toggie for locking the said contacts together.

l0. In a switch of the class described, a main frame having a piurality of horizontal shelves, a hollow insulator mounted in the top shelf, said insulator opening downwardly and containing a contact element, a tubular insulator mounted in the next lower shelf in line with the iirst insulator and containing Contact sleeve, a rodlike contact element extending through said contact sleeve and in continuous electrical engagement therewith and adapted to be thrust into resilient engagement with said contact element, a tubular insulating sleeve telescoping with said hollow insulator and said tubular insulator and being anchored to the rodlike contact element, a movable frame having a vertical rectilinear guido mounted on the two upper shelves of the main frame, said movable frame being anchored to the tubular insulating sleeve, a cross shaft mounted on the second shelf adjacent the tubular insulator, a metallic arm rigid with the cross shaft, a link pivotally connected to the arm and to the movable frame, said link permitting lthe swinging metallic arm to shift the movable frame on said guide, said link and said arm cooperating to form a locking toggle extending in a generally vertical direction when the rodlike contact is forced into engagement with the contact element,

l1. In a switch of the class described, a main frame having a plurality of horizontal shelves, a hollow insulator mounted in the top shelf, said insulator opening downwardly and containing a contact element, a tubular insulator mounted in the next lower shelf in line with the first insulator and containing a Contact sleeve, a` rodlike contact element extending through said contact sleeve and in continuous electrical engagement therewith and adapted to be thrust into resilient engagement with said Contact element, a tubulai` insulating sleeve telescoping with said hollow insulator and said tubular insulator and being anchored to the rodlike contact element, a movable frame having a vertical rectilinear guide mounted on the two upper shelves of the main frame, said movable frame being anchored to the tubular insulating sleeve, across shaft mounted on the second shelf adjacent the tubular insulator, a metallic arm rigid with the cross shaft, a link pivotally connected to the arm and to the movable frame, said link permitting the swinging metallic arm to shift the movable frame on said guide, said link and said arm cooperating to form a locking toggle extending in a generally vertical direction when the rodlike contact is forced into engagement with the contact element, a bottom shelf, and a contact adapted to be engaged by said rodlike contact element when said metallic arm is swung downwardly to disconnect the rodlike element from the contact element.

12. An outdoor Weather-protected switch for switching primary electric power circuits, comprising a metallic mounting frame for supportn ing the operating parts, said frame providing three shelves horizontally extending and vertically aligned, a hollow inverted cuplike insulator supported in the topmcst shelf and containing a Contact element within the cup and a connected terminal element outside the cup, an

insulating sleeve mounted in the second shelf in alignment with the rst insulator, a sleeve contact supported within said insulating sleeve and having a terminal external of and carried on the sleeve, a stationary contact mounted on the lowermost shelf in alignment with the sleeve Contact, a rodlike plunger element slidably mounted in the sleeve contact to make contact continuously therewith and having Contact elements at its opposite ends for engaging the Contact element and stationary Contact, one at a time, movable means connected to the plunger` for shifting the same, said means including an intermediate insulating sleeve adapted to tele scope with the cuplike insulator and the insulating sleeve and an auxiliary frame, guiding rods having their ends mounted in said two upper shelves, and guide sleeves lying within the oonlines of the auxiliary frame for guiding the rodlike Contact independently of the sleeve Contact, said guide rods lying adjacent the sides of the intermediate insulating sleeve and being covered with insulation to avoid reducing the striking distance by the presence of the rods.

13. In combination, a metallic frame 32 having three shelves i3, 20, 2l, an inverted cup insulator l stationarily mounted in the top shelf I8, a

main switch Contact i3 therein, a stationary sleeve insulator l2 mounted in the second shelf 20, a movable sleeve insulator ll telescoping inside the cup insulator l and outside the stationary sleeve insulator I2 to provide v/ater-shed ding exterior, a rodlike Contact member 14 fixedly mounted in the movable sleeve insulator Il, a pair of guide rods i connecting the top I8 and second shelf 2G, a movable frame 25 carrying the movable sleeve l l, said latter frame having guides 138 on said guide rods 5%, a tubular sleeve and terminal member I5 anchored on the lower end of the stationary sleeve insulator l2, said last named member l5 comprising a tubular Contact portion Sl lying inside the stationary sleeve insulator 2 and in slidable Contact with the rodlike contact i4, an external line terminal 91' and a downwardly projecting tubular extension, a stationary contact EG engageable by the lower end of the rodlike Contact member ld, said last named Contact I6 being mounted on the lower shelf 2l, and a sleeve of insulation l1 coupled to said tubular extension and forming a continuation of the stationary sleeve insulator l2 for housing the rodlike Contact i4 and forming a Water shed for said stationary Contact i6.

FRED FARRELL.

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