US1631012A - Switch - Google Patents

Description

May 31;, 1927. 1,631,012

N. J. CONRAD SWITCH Filed DEC 12. 1-925 '8 Sheets-Sheet l s Sheets-Sheet M m R I CWM J a .N

mm NW QM qffivarzfcr I Nz'c/volas J Conrad a Sheets-Sheet 5 ay N. J. CONRAD SWITCH Filed Dec. I2, 1925 May 1927- ,N. J. CONRAD SWITCH Filed Dec. 12, 192

8 Sheets-Sheet May 31, 1927.. 1,631,012

N; J. CONRAD SWITCH Filed Dec. 12, 1925 8 Sheets-Sheet 6 lV/C770Zc15 J Conrac/ MiG/p 1331012 Mal, 1927' :N. .J. CONRAD SWITCH- Filed Dec. 12, 1925 8 Sheets-Sheet 8 2 wgw Patented May 31, 1927.

UNITED STATES PATENT OFFICE.

NICHOLAS J. CONRAD, O! CHICAGO, ILLINOIS, ASSIGNOR TO SCHWEI'IZEB & OONBAD, OI CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SWITCH.

Application filed December 12, 1925. Serial No. 74,930.

My invention relates to switches, and more articularly of the class which is employ for interrupting current flow in open air. While the particular embodiment which I have elected is an air break switch, it is to be understood that the invention is not limited to air break switches, but may be employed for breaking the circuit in other media than air.

The particular feature of importance in the present invention is the employment of an electric fuse, preferably of hi h current rupturing capacity as a means or suppressing the are which would otherwise be formed at the main switch contacts by separation of such contacts.

I am aware that a fuse of this character has been employed in a similar situation for suppressing the are which would otherwise be drawn at the main switch contacts, as shown, for example, in the patent to Schweitzer No. 1,211,967, of January 9, 191?, in which the main contacts of the switch are shunted by a fuse of high current interrupting capacity either at the instant when the contacts are separated or shortly thereafter, as shown in said patent.

According to the present invention, the switching contacts are separated by a motion which first tends to draw an are between them and which thereafter shunts the arc with the fuse for a period suflicient to establish a circuit through the fuse and to suppress the are at the main contacts, and then the main contacts continue their separating movement to include a further break between them and between one of those contacts and the fuse contact or terminal.

The spacing of the auxiliary fuse contact may be suitably controlled and the inductance and resistance of the fuse circuit may be so proportioned as to secure a suitembodiment which-I have shown, there are a stationary switch contact anda movable switch contact and a movable fuse contact. The movable switch contact leaves the stationary switch contact, throwing the fuse into the circuit across the arc and then the .fuse contact is moved to separate the fuse have also shown in the second embodiment certain improvements in switches relating to the locking means therefor, the quick break mechanism therefor, the contact mechanism therefor, and other features which will be apparent from the detailed description.

Now, in order to acquaint those skilled in the art with the manner of contstructing REISSUED and operating a device embodying my invention, I shall describe in connection with the accompanying drawings two specific embodiments of the invention.

In the drawings,

Fig. 1 is a side elevational view of a switch embodying my present invention;

Fig. 2 is a diagram of connections and mode of operation of the same;

Fig. 2 is a diagram of connections and mode of operation of a modified form of switch;

Fig. 3 is a top plan view of the switch shown in Fig. 1;

Fig. 4 is a fragmentary elevational view partly in section, showing the operating crank for moving the movable switch" contact;

Fig. 5 is a side elevational' view partly in section, showing the operating mechanism for changing the fuses 1n the magazine for successive operations of the switch;

Fig. 6 is a fragmentary sectional view taken on the line 66 of Fig. 5, showing the means for moving the selector contact of the fuse magazine;

Fig. 7 is a similar fragmentary section taken on the line 77 of F1 5;

Fi 8 is a plan view 0 the stationary switc contact showing one of the movable 'aws for embracing the end of the switch lade, and associated parts;

Fig. 9 is a top plan view of the operating crank shown in ig. 4;

Fig. 10 is a fragmentary view showing the quick throw spring connection in the operatin rod for operating one or more of the switc es of this character;

Fig. 11 is a side elevational view of a modified form of switch;

Fig. 12 is a like view of the same showing the switch in partly open position;

"Fig. 13 is a top plan view of the switch;

Fig. 14 is a rear side elevational view of the switch shown in Fig. 11;

Fig. 15 is an end elevation of the switch as viewed from the left end of Fig. 14;

Fig. 16 is a cross sectional view taken through the horizontal axis of the rear end of theswitch;

Fig. 17 is a fragmentary sectional view taken on the line 1717 of Fig. 16;

Fig. 18 is a section through the switch taken online 18-18 of Fig. 13; and

Fi 19 is a fragmentary view of a contact.

for t e switch bar bearing the fuse for use in a modified embodiment of the switch shown in Fi 11 to 14, inclusive. v

Re erring now to the form of switch shown in Fi s. 1 to 10, inclusive, a base member 20 rovi es a support for two stationary insuators 21 and 22 and a rotating or oscillating insulator 23 adapted to be rocked on its own vertical shaft. A bridge bar or frame 24 is connected to the top of the insulator 22, being rigidly secured thereto, and is connected to the top of insulator 23 by a suitable journal bearing 25, shown in Fig. 4, which conmeets the to of the rocking insulator 23 with the crank disc 26 bearing crank pin 27. This crank pin 27 is connected to a pitman or connecting rod 28, which in turn is connected b a suitable bracket arm to each of the side inks 30 which are pivoted upon the ivot bearing arms 31. These arms or Brackets are formed as an inte ral part of the frame 24. A second pair 0 links 32, 32

, is pivoted on the bearings 33, 33, which bearings are also formed on the frame memher 24. The links 32 are shorter than the links 30. Both sets of links 30 and 32 are pivoted at their forward ends to the switch arm 34, the outer end of which comprises a blade or contact portion 35. .Thisblade orcontact portion 35 runs back to the pivots 36 and 37, there being sidebraces 38, 38 secured at their forward ends, as indicated at 39, to the main blade member 35, and con-. nected at their rear ends to the pivots 36 and 37 with suitable counter balancing springs 40 .mounted on the pivot rod 36 tending to throw the switch into the dotted line position, as shown in Fig. 1.

The side braces 38 are connected at their ends to the central bar 34 by brackets 41, so that the switch is braced laterally. The pairs of links 30 and 32areconnected together by a post, as indicated at 42 and 43, to brace'the operating mechanism of the switch. It will now be seen that the stationary frame 24, the links 30 and 32, and the connected arm 34, comprise a means consisting of four members pivotally connected to each other in a closed figure, for moving the switch contact 35 by a plunging motion from the open position as shown in dotted lines in Fig. 1, to the closed position as shown in full lines.

The movable switch arm 34 carries a air of arcing fingers 45, 45 anchored at' t eir ends by clamps 46 to the switch bar 34 and having their free ends formed into loops, as-

indieated at 47 in Fig. 1, these arcing fingers lying upon opposite sides of a stationary arcing finger 48 mounted upon the top plate 49 through the medium of an integral racket 50. These arcing fingers 45 are preferably steel rods which lie upon opposite sides of the stationary arcing finger 48.

The stationary contact is mounted in a housing 51 having a flared guiding opening 52 for guiding the movable contact member 35 into engagement with the jaws 53, 53. These jaws 53, 53 are connected by flexible braided conductors 54, 54 to the terminal block 55, this terminal block 55 having a pair of supporting ears 56, 56 by which it is mounted upon the base 57 of the housing 51. The terminal block 55' also has a rearwardl extending lug or bolting terminal 58 whic may be connected directly or indirectl with the series conductor 59, as shown in *ig. 5. The contact clip 53 is connected to the flexible conductor 54 by means of a stud 60 which is secured in this contact member 53 and passes through the flexible conductor 54. A'clamping nut 61 is threaded on the stud 6O andit 'draws the flexible conductor 54 against the contact 53. At its outer end where the contact member is flared, the flexible conductor 54 is connected to the clip by means of the machine screw 62. The stud 60 serves in addition to clamping the flexible conductor 54 to the contact 53, the purpose of guiding the contact 53' upon the outer end of the spring 63. The spring 63 passes loosely over the end of the stud 60 and then has a cotter pin 64 extending through theend of the stud to keep the spring in place. 0 r

In order to guide the contact clip 53 in line with the spring 63, I provide studs 65 which are secured in the contact clip 53 and extend through the flexible conductor 54 loosely through holes in the spring 63 to guide the contact clip 53 and yet to permit sufiicient free motion of the clip 53 to per- Init it to adjust itself to the face of "the contact 35 forming the end of the switch blade", I t U o t The "spring 631's secured at its re'ar end tothe terminal post 55, the spring thereby "f'ser'ving as a cantilever spring. The s ring maybe made upjfof 'several leaves 0 dif fer'ent lengths, asfor example, the additionalleavestiti and 67as shown inFig. 8,

all having their rcar'ends clamped under the clip 8 and' sccure d to the post or terglsingle set of springs on each side, the springs may?fbe f double fon each"side, that is, ar- *'ranged one above tl'iefother.

, The operation ofithe switch thus far described willfbei apparent. \Vhcn the movable insulators; is rotated on its jjo iirnal'25' the c ank pin; 27 being shown i n fliig iiieves the rod 28 pivot on,. t h e bracket 31Q'and"com ')elling movement bf the linksf82 "@(1'534, whereby the movable contact 35' is withdrawn from the.CQI tact ,.clips,53through a motion which terminatestheposition of these parts, as shown in dotted lines in Fig. 1. The arcing fingers 47 leave the arcing contact 48 after the main contact 35 has left'the contact clips 53, so that any are which may be drawn by the switch in opening will be sustained by the auxiliary non-current carrying contact instead of the main contacts 35, Q

So farthe operation of the switch is no different from the operation of other switches of this class with respect to the interruption of current flow.

I have provided an auxiliary contact which lies in the path of the arcing contacts 47 after they leave the stationary contacts 48, and so disposed with respect to the travel of the main contact that after the main contacts are openand an arc is drawn at the contacts 47, 48, further movement of the switch towards its fully open position will bring the auxiliary contacts 47 into engagement with the auxiliary contact 70, this auxiliary contact 70 being so spaced that further opening movement of the switch will not tend to permit re-establishment of an are at the main stationary contacts 53, 48. Preferably, the auxiliary contact 70 comprises a short tubular section of metal mounted upon an iron rod 71, the ends of which are secured to a suitable bracket member 72 mounted upon an insulator 73, the base of which is supported upon a bracket 74 mounted on top of the main stationary insulator 21.

The frame or bracket 72 is open at 1ts center to receive the arcing contact or. horn member 75, which extends diagonally upwardly from the bracket 72 for the purpose of forming a horn gap interrupter in case of failure of thecswitch to function in normal operation. a

The bracket 72 is connected in turn to a rearwardly extending frame member 76 which supports the fuse magazine frame 77 at its rear end. The bracket member 74, which is mounted upon thestationary insulater 21, supports aframe member 78 which .is in the shapeof a U., Across the terminals of the U there is connected a bar 79 of insulatingmaterial, and upon this bar .of insulating material there areclamped the con-. tact 111c1nbers.80,-8l and.82,.the contact members in turn being connected to fuse clips 83. 84 and 85, respectively. lhe,fusefranie .77 also has fuse clips 86, .87 and 88 corresponding to the fuse clips83, 84and85 at the lower end, and between these pairs of fuse. clips I mount the enclosed .carbon tetrachloride fuses now fwell known in the market. "Any other equivalent fuse, or fuse ofhiglifinterruptingcapacity, might be e m-' ployed instead. .These; fuses; are preferably offlthe type disclosed infmy, co-pendingapjplication, Serial" No. 631,268 filed ,April, 11, v1923. .These fuses are mounted infuseclips ofthe type also disclosed in said co-pending.

application. These fuse clips are characterized by the employment of wire bails 92 which serve to "compress the spring blades against the sides of the ferrules of the fuses and to hold the fuses against accidental re- I moval from the-fuse clips. The fuses which I have described have caps which may be blown from the end thereof and such ends are the upper ends of the fuses, and in this case the fuses are directed upwardly and to the rear ofthe switch so that severe blowing of any one of the fuses will not affect connected to the auxiliary fuse contact 70,

and at the lower ends the fuses are all connected to separate contacts 83, 84 and 85. These contacts are selected by a selector arm 94, the selector arm 94 being secured on a shaft 95 in the bracket member 74 which is hollow, and whichserves in addition to its function of supporting the insulator 73 and the U shapedv frame member78, as a housing for the pawl and ratchet mechanism for shifting the selector arm 94.

The shaft 95' has a ratchet wheel 96 secured upon the inner end thereof and this ratchet wheel 96 is adapted to be engaged by an operating pawl 97, which operating pawl is mounted upon the rocking lever 98.

The lever 98 inturn is pivoted to the push -rod 99, which push rod is guided through the terminal or clamping lug 55 of the stationary contact mechanism. The push rod 99 is adapted to be engaged by the end of the contact when the switch is closed for shifting the selector arm 94 from one of the fuse contacts to another fuse contact through the operation of the pawl and ratchet mechanism. The pawl 97 is guided in a suitable guideway 100, shown in Figs. 6 and 7, and is urged into contact with the ratchet wheel 96 by means of the spring 101. The ratchet wheel 96 is held against return motion by the spring pressed detent 102, which is ada ted to offer a predetermined degree of resistance to backward motion of the ratchet wheel 96 but to yield under excessive pressure to permit the selector arm 94 to be returned to its initial or inoperative position out of contact with members 80, 81 and 82, shown in dotted lines in Fig. 6.

The function of the spring pressed detent 102 is to prevent normal retrograde motion of the ratchet wheel 96 under the action of the pawl 97 when it returns to catch the next tooth. However, when it is desired to reset the mechanism by providing fresh fuses, the arm 94 must be moved back to the initial position and the yielding character of the awl 102 permits of this action by forci ly pulling the selector arm 94 from its advanced position to its initial position.

The operation of the mechanism thus far described is as follows Assuming that the selector arm 94 is in its initial position, as indicated by the lower most dotted line position in Fig. 6, the rock ing insulator 23 is operated to swing its eccentric so as to plunge the movable contact member 35 forward into engagement with the stationar contact 53. The two divergent arcing ngers 47 are guided upon the stationary arcing contact 48, so as to assist in guiding the contact 35 into place between the contact clips 53. As the switch is closed, the arcing fingers 47 may engage the contact 70, but since the selector arm 94 is in initial position where none of the fuses are in circuit, the fuse will not be operated and the switch will be closed normally. As the movable contact 35 is brought into position, it operates the push rod 99 and moves the swinging lever 98 to operate the pawl 97 to pull the ratchet wheel 96 one step forward. It is to be noted that the swinging lever 98 is normally urged by a spring 103 into advanced position, so that when the movable switch contact 35 plunges between the contact 53 the pawl 97, being in engagement with a tooth of the ratchet wheel, is able to advance the same one step to bring the selector arm 94 from one position to the next position. As the switch is thus closed the selector arm 94 is brought from the zero or initial position'to the first position for in- As the switch moves to open position the contact is first interrupted at the main contact, then at the arcing contacts 48, 47, and thereafter the arcing contacts 47 engage the auxiliary contact 70, which is connected to one of the fuses after the switch has so far opened that there is no reestablishment of the are at either the cont- act 35 or 48.

It is preferable that some means be provided for insuring a continued rapid motion of the movable elements of the switch after a starting operation-is initiated. This is to insure that after the arcing contacts 47 have been brought into engagement with the auxiliary contact 70, that further motion of the switch will be rapid and uninterrupted, so that there will be no tendenc to re-establish the are after the circuit as once been made through the auxiliar fuse circuit.

In Fig. 2 'I have provi ed a diagram of connections which illustrates the mode of operation of the switch shown in Fig. 1. The switch blade member is indicated at 104 and when it is" closed it makes contact normally with the stationary contacts 53, leading directly to the third conductor 59. Upon opening movement, the switch member 104 is first sufiiciently moved from .the stationary contact 53 to tend to destroy reformation of an are between said members 104 and 53 and then the switch member 104 is brought into contact with the auxiliary contact 70 and through one of the fuses 89, 90 or 91, as determined by the selector member 94.

Obviously a single fuse may be employed and after each operation of the switch the fuse may be changed. I have illustrated the fuse magazine and the lurality of fuses merely to indicate that the operation of the switch is not dependent upon renewing the fuse for each operation of the switch.

Since the fuse has a high current interrupting capacit it will interru t the flow of current quic ly with very little arcing and it is, therefore, necessary to separate the main contacts a distance great enough to prevent immediate reformation of the arc, the opening of the switch of my in- .vention being accompanied by very little arcing. The continued movement of the switch after switching in the fuse breaks the fuse circuit as well as the switch circuit itself, so that even if a fuse should fail to operate, the switch will properly open the circuit.

. of a capacity relatively great so that they be set to blow at 100 amperes.

will not be called upon to break the circuit unless the flow of current is of a char-' acter which would be difiicult to break at the air contact. For example, the fuses may Normal opening of the switch with normal load below 100 amperes would be easily performed by the switch operating as an air break switch. If the switch were opened on short circuit or excessive flow of current due to some other cause, in addition to the air break occurrin at the main contact, the liquid quenche break in the fuse being in series with the main contact would assist in interrupting the flow of current even if the same were of a relatively high character.

The proper sequence of events may be secured by suitable spacing of thefuse contact 70 and the provision of suitable resistance and reactance in the fuse circuit. Since this is in circuit only so long as the fuse is subject to current flow, no apprecias is clear from the diagram of Fig. 2.

These two interrupting elements, namely,

.the automatic liquid quenched fuse and the air break switch operate simultaneously and in series with each other, so that there is obtained the effect of multiple breaks, one

of which breaks at least is liquid quenched.

It will also be apparent to those skilled in the art that the relation of the movable and stationary contacts may be reversed, if desired. For example, in Fig. 2*, I have indicated a stationary contact 10'? adapted to be engaged by a switch blade 106 which normally carries the current flow and which,

has attached to it an auxiliary blade 108 with an insulating section carrying a fuse 109, which may be of the same character as I- have previously described, namely, a carbon tetrachloride fuse.

The two blades ,106 and 108 are in this case connected together so that when the blade'106 moves away from the contact 107 during normal opening of the switch, an arc may form between said contact 107 and the switch blade 106, but continued motion of the switch blade 106 carries the blade 108 into contact with the stationary contact 107, thereby extinguishing the arc"be-' tween contact 107 and switch blade 106 and directing the current. flow through the fuse 109, the blade 108 continuing in its motion to draw away from the contact 107, so that the two breaks, namely, the air break and the liquid quenched break are in series with recoil may be employed, for example, in

the vertical operating rod by which one or more switches of the character shown in Fig. l are operated in unison as, for example, three switches in a three phase system, the rod may be formed in two sections 110 and 111 with a spring cage and catch member 112 mounted on the section 110, this cage having a circular shoulder 113 which is caught by a swinging pawl 114 fixed on a suitable abutment 115. The lower section of the rod has a spring controlled plunger 116 secured to the upper end thereof. Between the plunger 116 and the bottom of the cage 112 there is confined a compression spring 117 which normally holds the sections 110 and 111 of the operating rod together in unison. The plunger 116 has a trip member 118 projectin out through a slot in the case 112 and this trip finger 118 is adapted to engage a co-operat-' ing trip member 119 on the upper end of the pawl 114. As a result, the rod section 111 may be drawn down putting the spring 117 under compression while the rod section 110 to which the switch mechanism proper is connected remains stationary. This action is carried to a point where the spring is compressed almost to its limit and then. the trip 118 engages the nose of the pawl at 119, throwing the pawl 114 out of engagement with the shoulder 113 and thereby releasing the upper rod section 110 to permit the recoil of the spring 117 to throw the switch to completely open position.

Obviously, a quick break. mechanism of this character may be employed on each individual switch in the case of separate or individually operated switches, but where "there are gang switches the quick throw I shall now refer 'to the second embodicontact having the main switch blade 125 'of the spring 132 pivoted thereupon. The insulator 122 bears the split contact 124 for engaging wlth the free end of the blade 125.

A pair of guiding and locking horns 126 are mounted adjacent the split contact 124 for guiding the main switch blade 125 into contact with its co-operating split contact 124.

The arcing contact 126, 126 has at each side, that is, at each horn, a shoulder member 127 which extends towards the hinge contact 123 for the purpose of holding the auxiliary or quick break blade 128, which is pivoted to the main blade 125.

The auxiliary or quick break blade 128 is hinged at its rear end on the screw 129 to the swinging loop 130 which is pivoted upon the main blade 125 adjacent its rear end. The auxiliary blade 128 is connected electrically to the main blade 125 by a flexible copper braided strap 131 and mechanically the two blades are connected together throu h the spring 132, one end of which is looped about the pin 133 upon each side of the arcing blade 128 and the central part of which spring extends over the top of the main blade 125, as indicated at 134, this art being held in a notch in the blade 125v y means of the screw 135 and there being helical coils as indicated at 136 upon each side of the main blade 125. The structure ermits pivoting of the arcing blade 128 a out the screw 129 and also ermits endwise motionof the blade 128, the loop 130 serving as a guide for the same. This endwise movement of the blade 129 is desirable when the switch is closed to permit the pin 137 to slide along the tapered edge of the catch or detent 127 and then to be rojected under the shoulder of the same. he-main blade 125 has an operating'eye 138 pivoted on across pin 139, this operating eye having a hook extension 140 beyond the pivot 139 with a suitable notch 141 for engaging a pin 142 which is mounted crosswise 1n the arcing blade 128. A pair of stop pins 143 and 144 limit the motion of the eye and its connected hook .member 140. A spring 145, which is coiled about the pin 139, normally urges the hook 'member 140 in a clockwise direction as viewed in Fig. 11, to cause the slot 141 to catch the pin 142.

. The operation of the switch thus far described is as follows:.

Assuming that the switch is in closed position as viewed in Fig. 11, the main-blade 125 is pivoted on the hinge contact 123 and is embraced by the split contact 124; This main blade also lies between the arcing and guiding horns 126. The arcing1 as its pin 137 caught under t e shoulder 127 and ,the forward end of this blade is engaged by a contact spring 146, this contact spring being riveted at its upper end, as inblade 128 dicated at 147 to the arcin horn 126 upon each side of the auxiliary b lade 128. Since the auxiliar blade 128 is locked by the de tent 127 an to the auxiliary blade 128 through the hook member 140 and pin 142, it will be seen that the switch is thereby locked in closed position.

If, now, the operator wishes to open the switch, the operating hook is inserted in the eye 138 and the eye is moved to the left as viewed in Fig. 11, thereby releasing the hook member 140 from the pin 142. Thereupon, the main blade 125 may be moved out of the split contact 124, as indicated in dotted lines in Fig. 11, the arcing blade or quick break blade 128 remaining in contact through the springs 146 and' the arcing horns 126, because of the pin 137 which is still retained under the shoulder 127. Continued motion of the main blade withdraws the pin 137 from the shoulder 127 when the switch has moved toa position which is substantially open. It will be observed that the tendency of the spring 132 is to expand "and keep. the pin 137 under the shoulder 127.

As soon as the pin leaves contact with the' shoulder 127, the spring 132 swings the arcing blade 128 in a counter clockwise direction up into its normal position where the pin 142 is caught by the hook 140, as is illustrated in the dotted line position shown in Fig. 12. a l

The switch break mechanism which I have described is novel per se, and so is the lock which I have described. These mechanisms are combined, however, with the carbon tetrachloride fuse of the character previously described for the purpose of causing the actual .break or the greater part thereof to occur within the fuse while the main parts of the switch are separating. In the present case an auxiliary fuse carrying blade 148 is hinged to the main blade 125, as will be clear.

from Fig. 13.

Referring to seen that I have disposed adjacent one side of the mainrblade 125 the base or le 150 of a bracket member 149, and u on t e other side a-plate 151 which is rivete to the blade. Plate 151 forms one le bracket shown at 152 in Fig. 13, the opposite leg 153 of which extends outside of the outer leg of the bracket 149. The bracket 149 has its other leg 154 adjacent the leg 153 of the bracket 152, so that said bracket 149 is confined between the blade 125 on one side and the opposite leg of the bracket 153 on the other, with the shaft or pivot pin 155 extending through all of these parts and being pinned, as indicated at 156, to the plate 151 of bracket 152. The bracket 149 has an extension 157 th which is bolted the fuse carrying blade 148, this blade being a strip of fibre or other suitable insulating material since the main blade is locked Figs. 13; 1c and 17, a will be 115 of a U-shapedand having clamped at itsforward end a bracket member 158 which has a forwardly extending contact member 159, preferably formed of apiece of rolled copper for ex tending the bracket 158 forward to engage the U shaped flat spring 160. The bracket member 158 in addition to being bolted to the insulating blade 148 has a laterally extending portion 161 which bears the fuse clip 162 for engaging the ferrule 163 of the fuse 164. The opposite ferrule 165 of the fuse 164 is mounted in a fuse clip 166 which in turn is mounted upon a laterally extending arm 167 integral with the bracket member 149.

The. extension 157 on the bracket 149 has an integral stop finger 168 reaching under the main switch blade 125, the hinge pin 155 having a helical spring 169 coiled about the same and having its-ends anchored in the bracket members 152 and 149, respectively, tending to hold the auxiliary blade 148 away from the main blade 125, that is, tending to move the auxiliary blade 148 with its fuse 164 in a clockwise direction with res ct to the main blade 125, as viewed in ig. 11. 'The flat loop spring 160 is inelectrical connection with the split contact 124 and connected to one side of the line. This spring 160 has its one side 171 connected to one side of the U shaped bracket 173, as shown in Fig. 14. The opposite side 174 serves as a stop for the free end of the spring 160. The latter arm 174 of bracket 173 is notched or slotted to receive the end of the contact member 159 and to hold the same against lateral displacement. The arm 175 of the sprin 160 engages the end of the contact 159 an holds 1t in contact electricall and mechanically until the main blade with its arcing contact have been moved a suflicient distance to prevent re-establishment of the are at the main contact after blowing of the fuse 164. The continued motion of the main switch blade then opens the auxiliary blade 148 with its fuse. I The operation of the switch will now be apparent. When the main blade 125 is opened. the arcing blade 128 lin rs in contact with the arcing horns 126 and the spring 146 until the blade has reached a osition where there is no danger of re-esta lishing the arc, whereupon the arcin or quick break blade 128 is snapped upward y by the spring 132, throwing the fuse 164 into the circuit, and continued movement of the main blade causes the auxiliary blade 148 with its coniliary blade 148, are so arranged with re spect to the bracket member 152 that after the main blade has reached a predetermined iliary blade until after the switch is closed.

If desired, a small ampere capacity fuse may be inserted on the mounting on the auxiliary blade when the switch is open, and employed as a test fuse to indicate that current will flow when the switch is closed. This is an important feature of the invention, particularly for installations where the switch is not to be closed under conditions where current will flow upon such closing. If the fuse blows it furnishes in such installations an indication that the switch should not be closed.

In the modification which I have above described, namely, where the fuse is mounted upon the auxiliary blade, the fuse is connected back in parallel with the main blade 125 upon closing of the switch, so that closing of the switch may be caused while the fuse is thus shunted and without danger of blowing the same.

It will be apparent from the foregoing that I have provided in both forms a pair of main contacts which normally carry the current and which are adapted to be separated for breaking the current flow, the first result of which is to switch in a fuse of high current interrupting capacity, the circuit through which is then broken by an air break secured by further opening movement of the main switch blade.

While inthe constructions shown in Figs. 11 to 18 the fuse is thrown immediately into circuit when the arcing blade or quick break blade 128 opens, it will be apparent that the fuse contact 159 may be brought into engagement with the pair of opposed spring contact 180, shown in Fig. 19 which may replace spring 160 and bracket 173, after the quick break of the main blade has started to open the circuit.

Normally, in the switch shown in Fig. 11, the quick break releases when the main blade is substantially at 45 position towards its fully open position. The fuse blade begins to open substantially at the time that the quick break blade releases. The fuse blade travels with the main blade for substantially the rest of the movement of the main blade after about the first 45.

I do not intend to be limited to the details shown and described.

capacity across the break between said con-,

tactsand thereafter continuing the movement of the movable contact to separate it further from the stationary contact and to disengage it from the fuse.

3. The-method of interrupting current flow which comprises conducting the current flow through a pair of relatively separable contacts, separating said contacts to draw an arc, brid ing the arcwith a current interrupting rupting capacity, then further separating said contacts and simultaneously disengaging said circuit interrupting means.

4. In combination, a pair of relatively movable switch contacts a fuse having a fuse contact at one terminal and having the other terminal connected permanently to one of said switch contacts, means for sepa rating said switch contacts by a relatively continuous movement, the separation of said switch contacts first throwing the fuse .in circuit and then by continuous movement disconnectin the fuse contact.

5. In combination, a pair of switch contacts, means for separating said contacts over a' definite path, a fuse connected permanently to one of said contacts and having "a contact lying at a definite point of said -path of separation to be engaged by and thereafter disconnected from one of said switch contacts.

' 6. In combination, a pair of relatively separable main switch contacts, means for separating said contacts by a substantially continuous movement, a fuse adapted to be connected across said contacts upon the separation thereof, and means for separating said fuse at one end from both of said contacts.

7. In combination, two switch contacts, a fuse having one end connected to one of the switch contacts, means to connect the other end of the fuse to the other switch contact when the switch starts to open, and

means for moving one of said switch contacts relative to the other to open the switch I and to cause the fuse to be disconnected.

'8. In combination, a pair of switch contacts, means for moving one of the switch contacts relative to the other, a fuse adapted evice of relatively high inter-.

to be connected across said switch contacts when they start to open for interrupting the current flow, said movable switch contact being adapted to have motion to separate the contacts after the current flow is interrupted at said fuse.

9. In combination, a stationary switch contact, a movable switch contact, said movable switch contact having an arcing finger for-taking the are between the stationary contact and the movable switch contact when the switch is open, an auxiliary stationary contact adapted to be engaged by the arcing contact after the main contacts are open, and a fuse connected between the auxiliary contact and the. main stationary contact, said arcing finger being moved away from the auxiliary contact by the opening movement of the switch.

10. In combination, a switch having a stationary contact member, a movable memher having a co-operating movable contact, an arcing finger, and means for moving the movable member to a predetermined open position, an auxiliary contact adapted to be engaged by the arcing finger when theswitch has moved to partially open position,

and a fuse of high current interrupting capacity connected between the auxiliary contact and the main stationary contact.

11. In combination, a switch comprisin a stationary contact member, a movable switchmember having a contactand an arcing finger, an auxiliary contact and an upwardly extending horn connected thereto, said movable member being'adapted to move we predetermined open position so that the arcing finger and the movable member will form a co-operating horn for extinguishing an are between said members, and an automatic liquid quenched circuit breaking member connected between the auxiliary contact and the main stationary contact.

12. In combination, a switch comprising a.

stationary contact, a movable contact, and'an .auxlllary stationary contact connected to the maln stationary contact, and an automatlc liquid quenched circuit breaker in said connection, said auxiliary contact being enga ed by the movable contact after the same as moved when the movable .contact is in a position sufliciently remote from the main stationary contact to prevent re-establishment of an arc therewith.

13. In combination, a stationary contact, a movable switch member normally engaging said stationary contact, means for moving the movable switch contact, a fuse, means for connecting the fuse between the movable switch contact and the stationary switch contact when the movable switch contact is in partly open position, and means for 14. In combination, a switch comprising I stationary contact, a movable contact, a plurality of fuses, an auxiliary contact adapted to be engaged by the movable contact when the switch is open, and means governed by operation of the switch for selectively connecting the fuses in circuit with said auxiliary contact.

15. In combination, a switch comprising a, stationary contact member, a movable contact member, an auxiliary contact member, a plurality of fuses adapted to be connected between the auxiliary contact and the main stationary contact, means for selectively connecting said fuses, said means being governed by operation of the main switch.

.16. .In combination, a switch having a stationary contact member, a movable contact member, an auxiliary contact member, a pinrality of fuses, and means controlled by operation of the movable switch member for connecting the fuses successively between the auxiliary contact member and one of said main switch members.

17. The method of interrupting the flow of a current through a pair of contacts which comprises separating the contacts, connecting a fuse of relatively high interrupting capacity in series in the circuit by continued separation of the contacts, and thereafter further separating the contacts and breaking the circuit through the fuse.

18. The method of interrupting the flow of a current through a palr of contacts which comprises separating the contacts, connecting a fuse of relatively high interrupting capacity in series in the circuit during continued separation of the contacts, and thereafter further separating the contacts and breaking the circuit through the fuse,

the several steps mentioned taking place as a continuous operation.

19. The method of interrupting the flow of a current through a pair of contacts which comprises separating the contacts, connecting a fuse of relatively high interrupting capacityin series in the circuit during continued separation of the contacts, and thereafter further separating the contacts and breaking the circuit through the fuse, the several steps mentioned taking place as a continuous operation and there bemg relative movement between one of the contacts and the fuse for disconnecting the fuse from the circuit.

20. In combination, a switch contact, a fuse connected at one end to said contact, a fuse contact connected to the other end of the fuse, and a second switch contact, there being relative movement between the contacts for opening and closing the switch contacts, said second contact upon opening thereof being moved successively out of operative relation to the first switch contact, into operative relation to the fuse contact to introduce the fuse into the circuit, andv then out of operative relation to the fuse contact. A

21. In combination, two switch contacts having relative movement, a fuse connected connected from the circuit 'by continued opening of the contacts.

In witness whereof, I hereunto subscribe my name this 10th day of December, 1925.

NICHOLAS ooNRAn-

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