US1549679A - Electric switching apparatus - Google Patents

Description

Aug. 11 1925.

1.. c; NICHOLSON ELECTRIC SWITCHING APPARATUS Filed Sept. 19, 1921 5 Sheets-Sheet l glvwemtoz V a. W 3371 elf EH42 Aug. 11, 1925. 1,549,679

L. c. NICHOLSON ELECTRIC SWITCHING APPARATUS Filed se t. 19, 9 s Sheets-Skieet :5

Elvwemtoz in c .M 351;; a r tom y W W Aug 1 1, 1925.

7 1,549,679 L. C. NlCHOLSQN ELECTRI C SWI TCHING APPARATU 5 Filed Sept. 19, 1921 S Sheets-Sheet 4 I amvewtoz 4 WM 351 auto (M WWW Aug. 11, 1925. 1,549,679

L. c. NICHOLSON ELECTRIC SWITCHING APPARATUS Filed Sp't. 19, 1921 s Sheets-Sheet 5 Patented Aug-11, 1925.

UNITED STATES LLC YYD C. NICHOLSON, OF EDEN, NEW YORK.

ELECTRIC SWITCHING APPARATUS.

Application filed. September 19, 1921. Serial No. 501,737.

To all whom it may concern:

Be it known that I, LLoYn G. NIoHoLsow, a citizen of the Uni-tedStates, and a resident of Eden, in the county of Erie and State of New York, have invented certain new and useful Improvements in Electric, Switching Apparatus, of which'the following is a specification.

My invention relates to improvements in electric switching apparatus and is particularly adapted to the openings of alternating current high tension circuits such as those on which a voltage of 10,000 volts or over exists, although it may be used to advantage on lower voltage circuits carrying heavy currents. One object of the inven- .tion is to provide a switch which is extremely quick in action. When used to its fullest extent the invention will provide for the operation of the circuit breaker in less than one-twenty-fii'th of a second, when a short circuit occurs on the line, so that the short circuit may be eliminated without disturbing the operation of rotating synchronous machinery on the connected system.

My present invention is in some respects an improvement upon that described in my Patent No. 1,402,310, for electric switching apparatus, issued Jan. 3, 1922. The said.

patent covers a construction in which the use of oil in which'a circuit breaks is avoided whereby the possibility of theproduction of explosive vapors is done away with. In the invention covered by the said patent, as well as in the present invention a pair of switch contacts are caused to separate when the circuit is to be-opened, these contacts by their separation causing current to flow through a Vaporizable liquid so that the liquid is immediately vaporized with the result that the pressure exerted by the vapors produced causes a rapid further separation of the contacts.

An object of my present invention is to produce an extremely eiiective and comparatively simple device of the character indicated. Furtherv objects consist in the provision of improved details of construc tion and combinations of parts, all of which will more clearly appear from the detailed description given below taken in connection respectively on lines 2-2, and 3-3 of-Fig. 1

.Fig. 4 is an endelevation of the apparatus viewed in the direction of the arrows I 7 v I I Flg. 5 18 a vertical section taken on line 5 5 of Fig. 3 on an enlarged scale;

Fig. 6 represents a detail of construction shown on an enlarged scale;

Fig. 7 is a partial side elevation of a switch arm with connected parts;

Figs. 8, 9 and 10 are respectively side elevations of a piston rod and upper and lower members of the piston, disassembled; i

Fig. 11 is' a plan View of the lower piston member;

Fig. 12 is a side elevation of the contact member carried by the lower end of the piston rod;

Fig. 13 is an end elevation of the switch arm shown in Fig. 7 with the contact carried thereby; and

-Fig. .14 is an end elevation of a portion of the apparatus utilized in a multipole switch embodying a modifiedform of my invention, certain parts being shown in section. 1

Referring to the drawings, the switch, in the embodiment shown in Fig. 1 is preferably formed of two units ofwhich the one shown at the right contains what I term the gun in which the contact is broken in a vaporizable liquid as previously referred to, together with mechanism for causing the operation of the gun' and other parts while the unit at the left carries a switch blade and a stopping dash-pot and switch closing mechanism.

The unit shown at the right comprises a pair of channel irons 58 supported upon insulators 55, these insulators having metal caps cemented thereto with transversely extending. channel irons 63, 64, secured thereon and supporting the channels 58. The leftha-nd unit is shown as having a frame work formed of a pair of channels 57, which are supported by transverse channels 53, 54, carried by metal caps which are cemented on suitable insulators 55, the insulators of both the left and right hand units being shown as supported upon a suitable supporting frame 59.

Referring to the righthand unit, a casting 16 is shown as mounted upon the channels 58. What I term the gun barrel of the switch is mounted on this casting.

As shown, what I term the gun barrel takes the form of a cylinder 1 formed of a suitable insulating material such as fabric impregnated with a phenolic condensation product, this material being of high mechanical strength, water proof and a good insulator; As shown in Fig. 5, the cylinder 1 is mounted in andsupported by a short cylindrical member 8 screw-threaded on a portion of its periphery and screwed into position within a cylindrical member 9, the internal diameter of which is greater than that of the cylinder 1. Member 9 is formed with a bottom closure member 9- which may be bolted or otherwise secured on the casting 16.

The contact members which are to be separated when the circuit is to be broken are mounted within the cylinder or gun barrel 1. A iston head 4 is mounted on the stem 7 which extends o'utof the upper end ofthe cylinder 1, the contact member 5 being screwed on the lower end of stem 7. The lower contact is. provided by the upper end ofrod 6 which extends up througha suitable stufling box 11 in the bottom portion 9 of the cylindrical member 9, the upper end of rod 6 and the bottom of contact member 5 normally being pressed together to form a good electrical contact. A chamber 9 is provided by cylindrical member 9 into which water or other va orizable liquid may be supplied, the liquid extending up into the interior of cylinder 1 to a point above the plane in which the contact members 5 and 6 engage. When contact members 5 and 6 are separated from each' other the water within the cylinder 1 immediately acts as a conductor between said switch contact members and the current flowing through the wa ter causes it to be rapidly vaporized to steam, and the pressureof the steam causes the piston 4 and associated parts operating in cylinder 1 of the gun to be shot out'of the gun with great force and rapidity.

The operating solenoid 23 is mounted on the transversely extending channel 64, be-.

tween the two channels 58. The core 22 of solenoid 23 is connected by a link 20 to a' bell crank21 which is pivoted on pin 10 supported by brackets 10 extending upwardly from the cylinder member 9 of the gun barrel construction. A spiral spring 67 is coiled about an extension of pin 10, as

shown in Fig. 3, this spring being arranged to tend to hold core 22 and connected parts in the position shown in Fig. 5 and to return the same to such position after the core has been lowered. To produce this result one end of the spring may be secured to bracket 10 and the other endof the spring may be suitably secured to bell crank 24;, or to pin 10, the bell crank being? keyed to this pin.

The switch arm 2, as shown in Fig. 1, is pivoted adjacent to'one end as shown at 40, to the brackets42 of the unit shown at the left. Switch arm 2, which may take the form of an I beam, as shown, has the piston stem 7 secured thereto adjacent its opposite end. As shown (Figs. 5 and 8) the piston stem 7 may have a pair'of upwardly extending lugs 7 which are secured to the switch arm 2 by a pin 7, it being understood that current is adapted to flow from switch arm 2 through lugs 7 or, if desired, by a flexible connection from arm'2, to the piston stem 7 and thence to the switch contact 5 and rod 6 in contact therewith.

Switch arm 2 likewise carries an auxiliary contact 17 ,which preferably takes the form of spring fingers brazed to switch arm 2, as shown in Fig. 13. Two switchblades 19 are pivotally mounted at their lower ends on pin 10 and have contacts at their upper ends adapted to engage between the contacts 17.

A stirrup 21 is secured to switch blades 19- and is provided at its outer end with a cross member 21. A path for current from switch blade 2 is provided by contacts 17 and 19 in parallel with the path provided by the pistonstem 7 contact 5 and rod 6, it being noted that the external switch blade 19 may parallel the entire length of the gun barrel 1. The switch blades 19 and 17 are provided to carry the load current in excess of that which the contacts 5, 6, would carry.

11811 core 22 moves downwardly by reason of excess current flowing through solenoid 23, as will be described hereafter,

the lefthand member 18 of hell crank 24,

(Fig. 5) moves some distance to the right, referring to Fig. 5, and then strikes a sharp blow against the cross piece 21 of stirrup 21 so as to sharply disengage switch blades 19 from contacts 17 and break the circuit extending through members 17 and 19 at this point. A link 25 is pivotally secured at its upper end to a lug formed on bell crank 24, the lowerxend of link 25 being connected by a pin and slot connection with a lever 15 which is pivotally mounted at one end to the casting 16. The rodv 6 extends downwardly through the stufiing box 11 at the bottom of-cylinder member 9 of the gun barrel into a cylinder 14, which is supported beneath the bottom member 9 of cylin der 9 by any suitable means such as the supporting bolts 14?. A piston 12 is provided within cylinder 14 at the lower end of rod 6, a rod 13 extending downwardly from piston 12 and out throughan opening in the bottom of cylinder 14.

Lever 15 carries at its free end a collar 15 slidably mounted on rod 6 immediately above piston 12,- lever 15 operating throug a suitable slot. in cylinder 14. When solenoid 23 is actuated to draw down core 22,

10 the slot in link 25 permitsa certain amount of movement of this link without affecting lever 15, until after-the arm 18 of bell crank 24 has struck a hammer blow against cross piece 21 of stirrup 21 to break the contact between switch members 17 and 19 as described. Thereafter the upper end of the slot in link strikes against the pin 25 which is secured to lever 15 and is slidably mounted in the slot. This results in rod 6' 0 being pushed down 'a short distance to separate contact 5 from the upper end of the rod.

The separation of contacts 5 and 6 as.

stated above causes the immediate vaporiza- 25 tion of, the liquid in the gun barrel, as stated, and the-pressure of the: steam or gas formed, pressing upwardly on .iston 4 forces the piston rapidly out of the gun barrel. Rod

6 is also rapidly pushed downwards by the pressure of'steam or gas on its upper end, i to the end of its stroke. It will be noted that the function of lever 15 and collar 15- is merely to start the motion of rod 6 away from contact 5, the motion of rod 6 being,

completed by the steam or gas pressure.

The lower end of rod 13 WhlCl'l extends out of cylinder 14 is .secured to a link .30,

the other end of which is pivotally secured to a bracket 32 extending downwardly from '40 channel 64. A spring 31 is connected at one end. to the channel 63 of the frame of the normal positions. The piston 12 fits closely within cylinder 14, the cylinder acting as .a dash-pot todampen and absorb the kinetic energy of rod 6 and connected parts during the operation of the switch. A rubber bumper 27 is shown as mounted oncasting 16 to be contacted against by bell crank 24 on the downwa" Cl movementof core 22 to stop the moving L .lItS without injury.

The tension on spring? 67 maybe adjusted to prevent the normal oad current through solenoid 23 fro'rngoperatingthe switch, this spring being overcome when a current in excess of the current for which the spring is adjusted comes over the, line. p

66 The apparatus may be designed to provide for a still larger load current in which case latching means are provided toprevent any movement of the core 22 and associated parts until a 'current greater than that for which the latch operating device is'set comes over the line. Such a construction is shown inthe drawings in which, referring to Figs. 1, 3 and 5, it will be noted that link 25 is provided adjacent its upper end with a lug 25 under which the .upper end of a lever 26 normally engages so as to prevent any downward movement of link 25. pivoted at 26 to the casting16 and is provided with an outwardly extending tail piece 26 (Fig. 3). A solenoid 28 is mounted on the casting 16 beneath tail piece 26 and-is Lever 26 is provided with a .core 28 which is drawn upwardly into the solenoid when the latter is. energized, the upper end of this core then pressing against the under side of tailpiece 26 to push the upper end of lever26 out from under lug 25 so as to unlatch the core 22 of solenoid 23 and the connected parts. Solenoid 28, if used, is connected in series with solenoid 23. Solenoid 28 is relativelysmall and-is-capable of adjustment for practically any current so that it may be adshown as being provided with a glass water gauge 36, .The reservoir is connected by pipe 34 with the chamber within the cylindrical member 9 of the gun barrel. No mechanism is required for regulating the liquid level in the reservoir since the switch operates satisfactorily with a large variation of water level.

Switch blade 2, as stated above, is pivoted at 40 to the brackets 42, the switch blade being keyed to the rotatable pin or shaft 40. The brackets 42 extend upwardly from the top of a dash-pot cylinder '45, which is mounted on the frame members 57 of the lefthand unit as shown in Fig. 1. Brackets 42 are provided with guideways 61, as shpwn in Fig.2, in which a cross head 66 is slidably mounted. A piston rod 43 is secured near its upper end to cross head 66 and extends downwardly through a suitable gland in the cover of cylinder 45. A piston 44 is mounted on the lower end of rod 43, within cylinder 45, which latter is adapted to contain oil or other suitable liquid.

The top of the rod 43 is connected to switch blade 2 in such a manner that arm 2 will .be permitted a considerable pivotal movement, upon the breakin of circuit between contacts 5 and 6 int c .gun barrel,

.inder in before the dash-pot piston '44 is brought into motion. In the preferred form ofapparatus this connection is made by means of a bent link 39 which is pivotally connected at one end to the upper end of piston rod 43, referring to Fig. 6. The other end of link 39 ispivotally connected to switch blade 2 at a point comparatively close to pivot 40. Asshown in the drawings the switch blade 2 may be provided with a saddle 41 to which the end of link 39 may be pivoted.

In the operation of this mechanism the link 39 exerts a cam like action on piston rod 43. When contacts 5 .and 6 separate in the gun barrel the piston rod 7 and piston 4 will move entirely out of the un barrel 1 before thedash-pot piston 44 is rought into motion. The dash-pot, piston rod and cross head, which are comparatively heavy, are then given a gradual acceleration, because of theQcam like action of link 39 on piston rod 43. The dash-pot cylinder45 is shown as bored with different diameters at difi'erent points along itslength, so as tosecure approximatelyuniform pressure of the oil against piston 44 by varying the clearance between the piston and the, walls of the cylproportion to the speed of the piston. x

Preferably the piston 4'within the gun barrel 1 is so-formed as to provide a sort of safety valve so that in case of opening a circuit' carrying ,a very large current the excessive sudden steam pressure within the gun barrel will be relieved.-

In the preferred form of construction, as

indicated in Figs. 7 to 12 inclusive, the

pistoncomprises an upper part 4 having an upwardly extending sleeve portion 4 which.

is adapted to be slipped over the portion 7 of reduced diameter of the piston rod 7. A lower piston member 4 is then positioned beneath piston member 4 and the contact terminal 5 screwed into'position below that, on the screw-threaded reduced diameter portion '7 of piston rod 7. The spring 3 coiled around the piston rod above piston member 4, serves to press the latter tightly against the lower piston member 4. The lower piston member is providedwith radial slots 4' and the upper piston member 4 is provided with corresponding tongues which are adapted to" fit over the slots 4*. The piston member 4 is also preferably provided with a pair of openings 4- therethrough and the upper piston member 4 is provided with -a pair of guide pins 4 which are adapted to seat in openings 4, so as to align ber 4 directly over the slots 4*. With this arrangement the piston parts 4 and 4 ordinarily work as a-unit and prevent the escape of steam past the same, spring 3 being qulte strong. If, however, steam of excessive pressure is suddenly generated in the gun the tongues extending around mem-- barrel, the pistonmember 4 will be raised somewhat against the action of spring 3 so shape, as is indicated at 1 to facilitate the piston 'enteringthe same on the return of the parts after the actuation of the switch.- It will be noted that the piston 4, 4, is not rigidly connected to the piston stem and is arranged to have a slight swinging motion.

about its axis when it enters the gun barrel, to permit it entering the same without rub- .bing' the inside surface of the barrel.

A pair of levers 46 are fulcrumed intermediate their lengths at the upper ends of a pair of standards 47 which are in turn pivoted at their lower ends to casting 49 which is secured across the top of frame members 57 Levers 46 are pivotally connected .at their righthand ends, referring to Fig. 1, to the upper-end of the dash-pot piston 43. At the leftha-nd end of levers 46 the latter are pivotally connected to a pair of vertical members 48, the lower ends of which are attached to a casting 48 secured on top of the insulator 50 which latter has a pin 52 of magnetic material extending downwardly I therefrom within a direct current solenoid 51. I

When the switch is in its open position, in which the switch blade 2 is thrown upwardly, as shown in Fig.6, the pin 52, constituting the core of solenoid 51, is u and will, of course, be drawn down into so enoid 51 when the latter is energized-so as to pull down the lefthand end of levers 46 and raise the righthand end of the same which results in swinging switch blade 2 about its pivot 40 back into position to close the switch, the piston 7 entering the gun barreluntil contact 5 engages firmly against the upper end of rod 6. Thesolenoid 51 is aided in this movement by spring 65 which, as shown in Fig. 2, is wound about pivot pin 40 and is so connected to pin 40 and to the switch blade 2 as to tend to press the switch blade into its closed osition, shown in Fig. 1. Solenoid 51 may e energized by manual control, or automatically.

The operation of the parts has been made clear to a considerable extent in connection with the preceding description. When the normal load current is flowing, the line current flows from the terminal 71 on bracket 42, shown in Fig. 2, through a flexible connection to shaft 40 and thence through the switch blade 2. The current flows 1n one path from switch blade 2 through piston rod 7 contact 5, rods 6 and13, link 30 to the frame'members 32, 58 and 64, and thence through solenoid 23, one terminal of which is connected to a frame member 58, to the machine and thence through solenoid 23 to i the ter inal 23 When the latch operating solenoi 28 is used the latter may be connected in series in the path just described as by connecting the same between the sole-,

noid 23 and'the frame member 58.

I When an undesirable overload occurs on the line, as for example a short circuitdue to an insulator failure or an are on the line, the increase in current in solenoid 23 causes it to pull down its core and open the switch- 17 19, whereupon all of the current is caused to flow through the shunt path through contact members 5 and 6. As the, core 22 descends further collar 15 on lever 15 depresses rod 6 so that the upper end of rod 6 is separated from. contact 5. The current flowing across the gap between members 5 and 6 rapidly vaporizes the water within the gun barrel to form steam and the steam pressure immediately forces piston 4 and associated parts rapidly out of the'gun barrel and forces rod 6 downwardly, rapidly and completely breaking the line circuit.

Any arc tending to form between contacts 5;

and 6 is extinguished or prevented from forming due to the high pressure of the steam. Furthermore the fact that the con 1 tacts are separated with great speed and in the presence of water or in a semi-conducting medium tendsto prevent the formation of an arc. The switch blade 2 swingsupward rapidly without retardation until after the piston 7 has beenfthrown entirely out of the gun barrel after whichthe cam link 39 becomes effective to depress the dashpot piston 44 whereupon the moving parts of the dash-pot construction are gradually vbrou ht into motion, the kinetic energy of switc blade 2 being thus absorbed and this member brought to rest.

Thereupon, or as soon as solenoid 5-1 is energized, switch blade 2 is swungback into operative position, piston4 agam entering the gun barrel and contact 5 coming into engagement with the upper end of rod. 6

- which has been moved upwardly into operative position, as soon as the inertia of its downward movement has been overcome, by

spring, 31, while at the same time spring 67 serves to raise core 22 and bell crank 24 into operative position, the arm 18 ofbell crank 24 striking against the rear cross piece 21 of stirrup 21 to force switch blades 19 back into engagement with switch contacts 17..

The apparatus operates so rapidly that the circuit 1s opened and the overload or short circuit switched ofi the line before the rotating synchronous machinery on parallel connected systems will get out of step or lose its load. On the deenergizing of solenoid 28, when the circuit is broken between contact 17 and 19 latch lever 26 swings back into position to again engage beneath lug 25 when link 25 again rises to the position shown in Fig. 5.

' The same principles of operation may be carried out in connection with a multipole switch, as is indicated in Fi 14. As many switches as desired, such or example as three, may be employed, each of the same being similar to the switch mechanism which has been described. Each of these will be provided with a switch blade 2 pivotally mounted on a shaft 40 these elements corresponding to the switch blade 2 and the shaft 40 previously described. As is shown in Fig. 14 shafts 40 are extended towards each other in alignment and are connected together by suitable insulators 7 0. As is indicated in Fig. 14, shafts 40 may be provided with springs correspondmg to the spring 65 previously described, and all of 4 the other parts of each switch apparatus may be the same as those already described.

chanically connected together, the opening of the circuit in two phases would of course, serve to open the third phase at the same time.

In-connectio-n with the apparatus which has been descrlbed above it may be noted that the mechanical construction whereby the movement of the .piston 7 out of the gun barrel is permitted to take place without retardation, the movement of' the switch blade 2 carrying the piston 7 being thereafter gradually brought to rest with a gradual acceleration of the movin parts of the dash-pot, has been found partlcularly effective. In this mechanism a rapidly moving fbody, namely the switch blade 2, is

ivoted near one end and is brought to rest y connecting the comparatively heavy parts of the stopping mechanism to the swinging switch blade near its pivot point where its motion is comparatively slow.

It will also be noted that the present construction provides'an arrangement whereby separation between the contacts 5 and 6 is caused to take place rapidly by causing the rod 6 to move downwardly through a considerable distance, comparatively speaking,

while the upper Contact has only to move upwardly through a comparatively' short dis tance until it is clear of the gun barrel. This arran ement permits the piston to (extend parallel with the throughout the entire length of the latter.

into the gun barrel only a comparatively short distance when it is in its operative position. It will also be noted that the auxiliary contact blade 19 extends in un barrel substantially It will also be noted that the construction is comparatively simple as to all its parts and is positive in its operation.

It will be understood that many changes and modifications may be made without de-.

parting from the spirit and scope of the invention, the invention not being limited to the details shown and described, the scope of the invention being'indicated by the appended claims.

What I claim is I 1. In switching apparatus, the combina- 1 tion of a cylinder open at one end, a piston thereln having its stem extending trom said cylinder, a contact carried by said plston, a

therein having its stem extending from saidcylinder, a contact carried by said piston, a second contact normally in engagement with said first; contact, a pivoted arm'outside said cylinder having the upper end of said piston stem connected thereto and car ried thereby, said contacts being included in an electric circuit, said piston being adapted to be moved rapidly out of said cylinder upon separation of said contacts, a

dash-pot having a piston, and means positione-d to'be actuated by a point on said pivoted arm near the said dash-pot piston.

3. In switching apparatus, the combinapivot thereof to actuate tion of a cylinder open atone end, a pistonq therein having its stem extending from said cylinder, a contact carried by said piston, a second contact normally in engagement with said first contact, a pivoted arm outside said cylinder having the upper end of said piston stem connected thereto and carried thereby, said contacts being included in an electric circuit, said piston being adapted to be moved rapidly out of said cylinder upon separation of said contacts, a dash-pot hav- 1ng a piston, andmeans positioned to be actuated by said pivoted arm .to actuate Said dash-pot piston only after said first named piston has moved out of said-cylinder.

4. In switching apparatus, the combination of a cylinder open at one end, a piston therein having its stem extending from said cylinder, a contact carried by said piston, a second contact normally in engagement with said first contact, a pivoted arm outside said cylinder having the upp'er end of said piston stem connected'thereto and carried thereby, said contacts being included in an electric circuit, said piston being adapted to be moved rapidly out of said vcylinder upon separation of said contacts, a dash-pot havmg a piston, and a cam linkconnecting said dash-pot piston with a point on said pivoted arm adjacent the pivotthereof whereby ressure will be exerted .on said dash-pot piston in gradually increasing amount to actuate the same and thereby stop the movement of said ivoted arm.

5. n switching apparatus, the combination of a cylinder open at one end, a piston therein having its stem extending from said cylinder, a contact carried by said piston, a

second contact normally in engagement therewith, a pivoted arm outside said cylinder having the upper end of said piston stem connected thereto and carried thereby, said contacts being includedv in an electric cir cuit, said piston being adapted to be moved rapidly out of said cylinder upon -separa; tion of said contacts, an auxiliary switch' member carried by said arm, a movable switch member adapted to engage therewith, said switch members being included in a circuit, inlshunt with said first and second contacts, and meansfor moving said movable switch member out of engagementwith said auxiliary switch member.

6. In switching apparatus, the combination of a cylinder open at one end, a piston therein having its stem extending from said cylinder, a contact carried by said piston, a second contact normally in engagement therewith, a pivoted arm outside said cylinder having the upper end .of said piston stem connected thereto and carried thereby, said contacts and arm being included in an electric circuit, said piston being adapted to be moved rapidly out of said cylinder upon separation of said contacts, an auxiliary switch member carried by said arm, and a movable switch member adapted to engage therewith and to extend parallel to the entire length of said cylinder, said switch members being included in a circuit in shunt with said first and second contacts.

7. Inswitching apparatus, the combination of cooperating switch contact members, a piston connectedtooperate one of said members, a cylinder in which said piston and said members operate, a solenoid, a switch outside said cylinder in shunt relation to said contact members comprising a tact members, a bell crank connected to the core of said solenoid and adapted to strike pivoted contact arm and at contact engaged thereby, means for maintaining a vaporizable liquid about said first mentioned cons a blow upon said pivoted arm to open the switch, upon movement of said core, and means for thereafter, during movement of said core, separating said =first mentioned contact members.

8Q In switching apparatus, the combination of cooperating switch contact members, a piston connected to operate one of said members, a cylinder in which 'said piston and said members operate, a solenoid, a switch outside said'cylinder in shunt relation to said contact members comprising a pivoted contact arm having a cross piece se-' cured thereto and a contact engaged by said arm, means for maintaining a vaporizable liquid about said first mentioned contact members, a lever connected to the core of said solenoid adapted upon movement of said core to move a distance and then strike said cross piece to disengage said pivoted arm from the contact engaged thereby, and

means 'for thereafter, during movement of said coreyseparating said first mentioned contact members.

9. In switching apparatus, the combination of cooperating switch contact members, a piston connected to operate one of said members, a cylinder in whichsaid piston and said members operate, a solenoid, a switch outside said cylinder in shunt relation to said contact members comprising a pivoted contact arm and a contact engaged thereby, means for, maintaining a vapor1z able liquid about said first mentioned con tact members, a bell crank connected to the core of said solenoid and adapted to strike a blow upon'said pivoted'arm to open the switch upon movement of said core', and link and'lever connections between said bell crank and the second of said first mentioned contacts to thereafter, during movement of said core, move said second contact out of engagement with the first mentioned of said contacts.

10. In switching apparatus, the combination of cooperating switch contact members, a piston connected to operate one of said members. a cylinder in which said piston and members operate, a dash-pot in alignment with said cylinder, a rod'connecting the second of said contact members with the 4 thereof, and connections between. the mov-' piston of said dash-pot, means for maintaming a vaporlzable liquid about said contact members, electro-responsive means having a movable element, a lever extending into said dash pot and engaging-the piston able element of said electroresponsive means and said lever for moving the second of said contact members out-of engagement with the firstnpon movement of said movable element a piston connected to operate one of said .members, a cylinder in which said. piston and members operate, a dashpot 'in alignment with said cylinder, a rod connects ing the second of said contact members with the piston ofsaid dash-pot, means for maintaining a vaporizable liquid about said contact members, electroresponsive means adapted when the current therethrough ex cee-ds a predetermined value, to separate' said contact members, said parts being are ranged to then permit a comparatively long movement of said rod and second contactmember, and,a shorter movement of said piston and first contact member within said v cylinder under the pressure of the vapor generated upon the separation of said contacts.

12. In switching apparatus, the combina- Y tion of cooperating switch contact members. a piston connected to operate one of said members, a cylinder in which said piston and said members operate, a solenoid. a switch outsidesaid cylinderin shunt relation to said contact members comprisinga pivoted contact arm and a contact engaged thereby, a connectionjbetween the core of said solenoid and said pivoted contact: arm for disengaging the latter from its cooperating contact after said core has moved an appreciable distance. upon how of excesscurrent through said solenoid. and means, including a lost motion connection for causing movement of said first mentioned connection to separate said first mentioned con- I tacts after movement of said pivoted contact arm.

' '13. In switching apparatus, the combination of cooperating switch contact members, a piston connected to operate one of said members, acylin'der in which said piston and said members operate, a solenoid having a core, means operated by movement of said core for controlling the movement ele'ctroresponsibe means in circuit with said solenoid adapted to trip said latch means when a current greater than a predetermined of the other of said contact members, latch means for preventing movement of said core,

value flows therethrough, and means for maintaining a vaporizable liquid about said firstmentioned contact members.

Signed at Buffalo in the county of Erie and State of New York, this 15'th day of Sept. A. D. 1921.

. LLOYD o. monoLson.

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