US2970192A - Electric switch - Google Patents

Description

Jam. 3l, WM R. P. BRuDGEs 2,970,192

ELECTRIC SWITCH Filed June 16, 1958 5 Sheets-Sheet l FIM 69- I 21 f3 I3 757 l 2% l f6? 22 227 fas fig /33 :laf/5 i0 153| I g 7. |f07 5: I

A ai;

fan. 3i, 1961 R. P. BRIDGE-:s

' ELECTRIC SWITCH 5 Sheets-Sheet Filed June 16, 1958 Jan. T3177, 1961 R. P. BRIDGES 2,970,192

ELECTRIC SWITCH Filed June 16, 1958 5 Sheets-Sheet 4 R. P. BRIDGES ELECTRIC swITcH Jan'. 31, 1961 5 Sheets-Sheet 5 Filed June 16, 1958 ELECTRIC SWITCH Ronald P. Bridges, Centraiia, Mo., assigner to A. B. `Chance Company, Centralia, Mo., a corporation of Missouri Filed June 16, 1958, Ser. No. 742,370

17 Claims. (Cl. Zim- 48) This invention relates to electric switches, and with regard to certain more specic features, to by-pass switches I nited States Patent useful in connection with circuits employing devices which from time to time, for repairs or the like are required to be disconnected from the circuits and electrically bypassed in a manner such that the service of the circuits may be maintained while the devices are disconnected. Such devices are, for example, grounded voltage regulators, requiring opening of their connections to ground when the switch is yopened and the by-pass connection established.

Among the several objects of the invention may be noted the provision of a by-pass switch of the class described having coplanar pivoted switch blades employing an improved linkage connecting them which is comparatively easy to operate; the provision of a switch of the class described having an improved by-pass switch component employing high-pressure contacts adapted to take high short-circuit 4current values without burning or liability of reopening under the magnetic forces involved with high currents; the provision of a switch of the class described in which said operating linkage is adapted for positive operation of the by-pass component as well as of other operating components; the provision of a switch of the class described having means for disconnecting grounded apparatus to be by-passed, such as a voltage regulator, without excessive arcing; and the provision of a switch of this class which is adapted to minimize leakage currents and which has improved strain insulators between its operating parts. Other objects and features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of which will be indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. l is a left side elevation of the switch in closed position, showing its application to a typical regulator by-pass circuit;

Fig. 2 is a right-side view of Fig. l;

Fig. 3 is an enlarged fragmentary cross section taken on line 3 3 o-f Fig. 2, showing the switch in said closed position;

Fig. 4 is a view similar to Fig. 3, showing the switch in an unlatched position of a irst latch;A

Fig. 5 is a view similar to Fig. 4, showing further advance of the switch toward open position wherein a seco-nd latch has opened;

Fig. 6 is a right side View of Fig. 2, showing the switch in an intermediate open position beyond the position shown in Fig. 5;

Fig. 7 is a view similar to Fig. 1, showing the switch in completely open position;

Figs. 8 andr 9 are oppositely viewed fragmentary trans- Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

The invention is an improvement upon constructions such as shown, for example, in U.S. Patent 2,824,916, dated February 25, 1958.

Referring now more particularly to the drawings, there is shown at numeral 1 a supporting bracket adapted to be bolted in position on a suitable support (not shown). Attached to the bracket 1 are insulator pins 3 on which are cemented insulators 5. Pad members 7 and 8 are cemented to the insulators, respectively.

B'olted to the upper pad member 7 is a conductor casting 9, the holding bolts being shown at 11. On its lower end it is formed as a bifurcated two-prong main switch contact 13. One prong is shown at 15, the other at 17, and the bifurcation at 19. At its upper end the conductor casting 9 is formed as a line terminal 21, having bolt holes 23 for accepting clamp parts (not shown) adapted electrically to connect one side of a line L to the switch.

Between its ends, the conductor casting 9 is formed as a cup 2.5, having large and small open ends. A plan of this cup and its contained parts is shown in Fig. 9. Bolted on curved pads 27 on its inside are opposite, kidney-shaped spring contact members 31, provided at their free inturned ends 33 with silver-button contacts 35. 'The inturned ends 33 are on a circle, thus placing contacts 35 on a circle. Within each contact member 31 is a kidney-shaped spring 37, the free ends 39 of which bias radially inward the free ends 33 of members 31 and their contacts 35. The holding bolts for the members 31 and 37 are shown at 41.

At the small open end of cup 25 is formed a shoulder 43, surrounded by a seat 45, adapted to support a tiange 47 on an insulating cup 49 composed, for example, of steatite. This steatite cup 49 has a hole 51 which slidably accepts a reduced extension 53 of a rod 55. Rod 55, including its extension 53, is composed of strong insulating material such as, for example, resin-impregnated glass fibres, or like strong insulating material.

Pinned to the rod 55 is a conductive spool 57, composed for example of copper, brass, bronze or the like. This spool has a central reduced portion 59 and end shoulders or anges 6.1 and 63. The pin connection is shown at I 67. A compression spring 65 is located in the space be tween the shouldered end 63 and the insulating extension 53. This spring reacts on the cup 49 and tends to bias the spool 57 out of the cup 25 into a position wherein the one shoulder 63 will be forced into tight engagement with the inwardly sprung contact buttons 35. When the spool is forced into position wherein the shoulder 63 is in the insulating cup 49, then contact is broken. The movement of the spool 57 is translatory, i.e., along a straight path established by the center line of the rod 55.

At numeral 69 is shown a horseshoe-shaped insulator composed, for example, of porcelain. This is provided (as shown in Fig. ll) with threaded sockets 71 for loosely receiving threaded studs 73 which are anchored by thermoplastic or thermosetting resin such as an epoxy resin inserted between the threads. Such resin prevents high local stresses. Fibre washers 241 are employed on the sides of the insulator 69 for the same purpose.

Nuts on one set of studs 73 hold the insulator 59 to the casting 9, and nuts on the other studs 73 hold conother at 137 at the end of the blade.

ductor casting 75 on the other margin of the horseshoeL insulator 69. Since the switch is ordinarily mounted in an upright position, as shown, the open end 73 of the horseshoe-shaped insulator 69 faces down. rIhus the insulator also operates as fa weather protective hood for the parts within it, including cup 25. The conductor member 75 is extended up to form a second line terminal 77, in which are openings '79 for the reception of clamp means (not shown) adapted to connect the other line wire of the circuit L.

Within the horseshoe insulator 69, the conductor casting 75 is provided with a second cup facing the cup 25. This cup is like the cup 25, as are also the contact parts contained therein, as will appear by comparing Figs. 8 and 9. To avoid circumlocution, such parts have been given the same numbers as the corresponding parts in cup 25, except that they have been primed, including the reference 25, referring to the second cup itself. It is to be noted, however, that there is no insulating cup such as 49 in the base of cup 25. This base is numbered 31, wherein is an opening 33 in which is an inwardly directed lug S projecting into a keyway S7 in the slidable insulating rod 55. When the rod 55 slides to the right, the shoulder 61 is adapted to engage the contact buttons 35', It will be apparent that holes 51 and 39 guide the translatory movement of the stepped rod 55, 53 and therefore the translatory movement of the spool 57.

On the outside of the cup bottom 31 the insulating rod 55 has pinned to it a member 39 which has a bridge portion 91 adapted to function as a catch. By its means, under conditions to be described, the assembly of the rod 55 and spool 57 may be forcibly pulled to the right, so as to place the shoulders 63 and 61 in tight springing engagement with the inwardly sprung contact buttons 35 and 35', respectively.

The conductor casting 75 is provided with a twopronged main switch contact 93, between the two prongs 95 and 97 of which is a bifurcation 99. The casting '75 is also formed with an ear 101, in which is anchored a crosspin 103 for purposes to appear.

Bolted to the lower pad member 3 is a conductor casting 1115 (see bolts 1117). This casting 1135 has a downwardly directed extension forming a terminal 1119 in which are openings 111 for attaching clamp means (not shown) to hold in engagement one side of a voltage regulator control line M. Bolted to the conductor member 105 is an insulator 113 (see bolts 115).

Bolted to the other side of the insulator 113 is a fourth conductor member 117 (see bolts 119). The casting 117 is also provided with line terminal 123, having openings 125 for receiving clamp means (not shown) for attaching the other side of the circuit M. It will be seen by reference to Fig. 1G that the insulator 113, like insulator 69, is provided with threaded openings 121 for loosely receiving the threaded bolts 115 or 119, as the case may be, a thermosetting or thermoplastic resin being employed as an anchor filler between the threads, for preventing any local stressing at the threads upon the porcelain of which the insulator 113 is composed. Here also fibre washers 243 are employed on both sides of the insulator for the same purpose.

Pivoted at 127 to a clevis 129 is a relatively long main switch blade or arm 131, formed by spaced side bars 133. These converge for some distance to a region at the free end of the blade, where they are parallel. One spacer in the converging part of the blade is shown at 135 and an- A third and ntermediate spacer is shown at 139, the details of which appear in Fig. 12. This spacer 139 is constituted by a bolt 141 passing through both sides 133 of the switch blade and through a tubular spacing pillar 143 between the parallel parts of the blades. Under the head of the bolt on the outside of one blade is a conical washer 145. Under a nut 147 at the other end of the bolt is a conical coil spring 148, reacting against the other blade 133. The

-bolt 141 is adapted to enter the bifurcation 99 in contact 93.

Pivoted at 149 to conductor casting 105 is a second and shorter main switch blade or arm 151, made up of two sides 153, which converge toward one another for some distance, as shown at 155, beyond which they are parallel. At their parallel ends they are joined by a spacer construction 157, which is the same as the spacer construction 139 already shown and described and therefore requiring no further written description. Parts of construction 157 corresponding to those of construction 139 are lettered the same, except that they are primed (see Fig. 12).

The parallel portions 153 of lthe short switch blade 151 carry a pivot 159 for a linked connection to a pivot 161 on the long blade 131. This connection includes a strain insulator 163, in the ends of which are anchored clevises and 157 for cooperation with the pins 159 and 161, respectively. Preferably, as shown, the centers of the pivots 127, 149, 159 and 161 are arranged on the corners of a parallelogram so that, as will be seen by consulting Figs. l and 7, a parallelogram type of motion is established between the switch blades 131 and 151. However, an exact parallelogram relationship is only preferable and not absolutely necessary, for any appropriate fourbar linkage arrangement is satisfactory. The term fourbar refers to parts 131, 151, 163 and the rigid parts connecting pivots 127 and 149.

When the switch is closed, the parallel-end portions of the short switch blade 151 engage the sides of the prong 15. The bolt 141 of spacer construction 157 enters the bifurcation 19, there being also some engagement of the ends of the blade with the other short prong 17. The springing action between the sides of the blade 151 effects springing electrical contact. Under these conditions, the parallel ends of the sides of the long blade 131 also engage the sides of the long prong 95, the spacer 139 entering the bifurcation 99, the resilient means associated with the spacer 139 pressing the sides of the blade against the sides of the prong 95. There is aiso some lateral engagement between adjacent side portions of the blade 131 with the short prong 17. Seating of the spacer pillar 143 in the bottom of the bifurcation 99 determines the switch-closed position.

At the end of the long switch blade 131, between the spacers 137 and 139, are provided several catch mechanisms associated with a prying lever, these being as follows (Figs. 3 5):

A long pivot pin 169 passes through both sides 133 of the long switch blade 131, for pivoting a rocker 171, located between the blade sides. This rocker has at its upper end an eye 173 with which the operating end of a linemans stick is cooperable. The lower end of the rocker 171 is provided with a lever 175, adapted for prying engagement with the end of the prong 97, which latter functions as a fulcrum. The rocker 171 carries a transverse stop finger 181 for limiting its rotation with respect to the sides 133 of the blade 131. it also carries a transverse lug 183 for engagement with the bifurcated camming end 185 of a catch finger 187 which is notched at 182. The finger 137 is pivoted at 189 between side members 133 of blade 131. After riding over cam 185, the lug 183 is adapted to engage in the notch 132. The opposite bifurcated end of the finger 187 is formed with a camming hook 191 adapted to cam over and hook on the opposite extending ends of pin 103.

At 177 is shown a second catch finger. This has a clevis portion 179 carried on pin 169 and iianking the sides of the rocker 171 but located between the opposite sides 133 of the switch blade 131. This catch finger 177 has a camming hook 193 for camming over and hooking the bridge portion 91 attached to the rod 55. Transverse lugs 195, extending from the hook 193, are adapted to engage the sides 133 of the blade 131. The finger 177 is also provided with an extension '1197, havnormas ing transverse lugs 199. These form additional stops engageable with the sides 133. A lug 201 on tinger 197 is engageable with lost motion by means of a lug 203 of lever I175. A tension spring 205 caught between holes in lugs on the finger 187 and the clevis portion 179 tends to rock both catch fingers 177 and 187 anti clockwise (Figs. 1-7) to initial positions. The lugs 199 determine the initial position of finger 177. Lugs 201i on finger 187, engageable with the sides of blade 131, determine the initial position of linger 187. Coil springs 297, anchored at the opposite respective ends of the stop finger 181 are wrapped around the ends of the pivot pin 169 and have their opposite ends anchored to the ends of a. crosspin 2119 which extends from the sides 133 of blade 131. These springs bias the rocker 171 anticlockwise (Figs. lv7 and 12).

Mechanical operation is as follows, starting with the position of parts shown in Fig. l. In this position, the switch is in what is herein referred to as the closed position, meaning the closed position of the main switch blades 131 and 151, wherein circuit M is connected in series with circuit L. In this position the by-pass switch conductor spool 57 is in open position relative to contacts 35 and 35 (see Fig. 3). At this time the hook 191 of finger 187 is behind the pin 103. The hook 193 of finger 177 is under the bridge 91 on the by-pass switch control rod 55. Spacing pillar `143: is seated in the bottom of the bifurcation 99.

In order to open the switch, the hooked end of a linemans stick is inserted into the eye 173 and the eye is pulled, as indicated by the adjacent dart. This causes the rocker 171 to rotate clockwise on pin 169. Lug 133 rides out of the notch 182, thus rotating finger 197 clockwise. This removes the hook 191 from behind the pin 103. At this time the switch blade 131 is drawn toward switch-opening position, as will be seen by comparing Figs. 3 and 4. During this interval, the hook 193 of finger 177 remains under the bridge 91 so that, with the aid of the spring 65, the rod 55 is moved to the right, thus positively forcing the shoulders 63 and 61 toward the contact buttons 35 and 35', respectively.

Further pulling on the eye 175 results in a prying action of the lever 175 on fulcrum 97, such as is illustrated in Fig. 4. As the lug 183 rides from the cam 1%, the finger 187 again assumes its anticlockwise position, ready to act as a latch upon the next closing operation when it occurs. The prying action functions not only to assist in swinging the blade 131 outward, but also takes up the lost motion between the lug 2113 on rocker 171 and the lug 2111 on linger 177 (see Fig. 4). Thus when the position of parts is reached shown in Fig. 5, the prying action has been substantially completed, the lugs 203 and 261 are engaged and further rotation of the rocker 171 causes the linger 177 to be rotated clockwise (Fig. 5). This removes the hook 19.3 from under the bridge 91. But this occurs only after substantial force has been exerted upon the rod 55 by the prying action of the lever `175 on bridge 91 during the time that hook 193 was engaged therewith. Thus before the hook 193 is released from bridge 91, the shoulders 63 and 61 have been forced into full tight engagement with the contacts 35 and 35. It will be understood that while the spring 65 aids in this action, it is the strong pull exerted by the prying action above described that moves the shoulders 63 and 61 into tight engagement with the strongly sprung contacts .35 and 35'. stood that the latter are strongly biased inward. In any event, at the time that the full stroke of the rod 55 has been accomplished. (Fig. 5), the lever 175 leaves the fulcrum 97 and the hook 193 leaves the bridge 91. Thereafter, further pull to the right on the eye 173 rotates the hook 193 clear of the bridge, allowing a fairly free opening swing of the switch blade 131 toward the full-open position (compare Figs. 5 and 7).

During the opening movement above described, the

1t will be under-` short switch blade 151, having the parallel-linkage connection with the long switch blade 131, also moves clockwise. The driving motion for this purpose is delivered from switch blade 131 to blade 151 through the insulated driving connecting link constituted by parts 163, 165, 167, compositely forming a drag link between blades 131 and 151.

Fig. 6 is a side View of the switch opposite to that of Figs. 1, 3, 4, 5 and 7. 1t illustrates an intermediate opening position in which a resilient arcing horn 211 is being sprung and wiped out of a conductive catch 213 (see also Fig. 13). Catch 213 forms a lateral extension from the contact 93, which is in conductive relation thereto (see attaching bolt 221). This catch has a bentover sloping portion 215, forming on its inside a pocket 217 for reception of the arcing horn 211, and on its outside forming a camming surface 219. The horn 211 is carried on blade 131, being anchored thereto at 227. In Fig. 6, the end of the arcing horn 211 is stressed by bending and about to snap out from the pocket 217, to be whipped against a resilient rubber pad 223. This pad is carried on a bracket 225, attached to the side of the long switch blade 131. The switch-opening position next succeeding that shown in Fig. 6 will result in the arcing horn being snapped to the dotted-line position shown in said Fig. 6. In further movements of the switch from the Fig. 6 to the Fig. 7 position, all electrical Contact is broken between the parts mounted on the upper insulator S and parts mounted on the lower insulator 5. But at this time an electrical by-pass connection has been established between the line terminals 21 and 77 by the conductive spool 57 in the contacts 35, 35. The open position of the switch, such. as shown in Fig. 7, is determined by contact between iiat end portions 237 on blade 151 contacting with ats 239 on casting 1115.

Reclosure of the switch is eiiected by placing the hooked end of the linemans stick in the eye 173 (Fig. 7) and pushing the switch toward the Fig. l position. During this closing movement, the end of the arcing horn 211 will ride down over outer cam surface 219, ultimately springing against the side of the member 213, thus forming a conductive engagement. lts position at this time is such that when the switch is subsequently reopened, it will move into the pocket 21.7 for snap-acting with.- drawal, as already described in connection with Fig. 6.

As the switch is further driven toward closed position, the end of the blade 151 will engage with the contact 13. Next the end of the blade 131 will engage the contact 93. When such resistance is met with as is associated with such contact, if not before, the rocker 171 will rotate anticlockwise on the pin 169. This will cause its lug 183 to engage cam 165, so as to throw the finger 187 aside, allowing lug 133 to come into position in the notch 182. This positions the finger 1817 so that its hook 191 is prepared to ride over the pin 163 in the finally closed position of the switch. But before this occurs, the hook 193 of finger 177 will have ridden over the bridge 91. Since the finger 177 at this time is free (with the exception of bias of the spring 205; lugs 201 and 293 separated), hook 193 rides resiliently over the bridge and intolatched engagement therewith. At this time the sides of the switch blade 131 contact the bridge 91. Upon further movement of the blade 131 toward switch-closed position, the rod 55 is forced to remove the shoulders 63 and 61 from the contacts 35 and 35', respectively, due to the driving connection between parts 91 and 177. This occurs against the return bias of spring 65. The openings 51 and 33 in parts 49 and 81 form straight-line guide means for the by-pass switch plug composed of parts 53, 55 and 57. Finally (as indicated in Fig. 3) the hook 191 rides over the pin 103 to effect a latching engagement therewith, thus holding the switch in closed position.

Electrical operation occurs as follows:

In the closed position of the switch, as shown in Figs.

i' l-3, the circuit from one side of line L is closed through casting 9, switch blade 151, casting 195, one side of line M, through winding 223E of voltage regulator 231, the other side of line M, casting 117, switch blade 131, casting 75' and to the o'her side of the line L. Circuit M is grounded at 235 through winding 233.

Upon initial opening movement of the switch, the terminals of the line L are electrically connected through castings 9 and 75. ri`his occurs through spool 57, which at this time has its shoulders 63- and 61 forced into er1- gagement with the contacts 35 and 35'. Then the circuits L and M are separated by movement of the switch arms 131 and 151 from the contacts 93 and 13. At this time (Fig. 6) there still remains an electrical connection from one side of line L to the regulator 231 as follows: casting 75, catch 213, arcing horn 211, part of switch blade 131, casting 117, one side of line M, winding 233 of regulator 231, and thence to the ground 235. As the switch is pulled further open through the Fig. 6 position, this circuit is broken with the snap action above described, which minimizes any arc. The egulator 231 is then completeiy disconnected but the opposite sides of circuit L have been connected together by what will hereinafter be referred to as the 1tay-pass switch constituted by the spool 57 and contacts 35, 35 and associated parts.

Upon reclosing the switch, the rst occurrence is to eect a reconnection between the arcing horn 211 and the catch 213. Next, switch blades 151 and 131 come into successive engagement with the contacts 13 and 93, respectively. Finally, the by- pass switch 57, 35, 35 is reopened, thus placing the circuit M in series with circuit L. At this time the arcing7 horn 211 is in such position on the side of catch 213 that when the switch is next reopened it will move into the pocket 217 for subsequent opening snap action.

Advantages of the invention are as follows:

The plug, plunger or bayonet type of by- pass switch 57, 35, 35', positioned perpendicularly to the current paths in line terminals 21 and 77 and adapted mechanically to be pulled into closed position when the switch blades 131 and 151 are pulled open, permits high contact pressures to be used between the contacts 35, 35 and the shoulders 63, 61, respectively. ri`hese high pressures minimize burning. Moreover, since the current path through the spool 57 is at right angles to the entering current paths in line terminals 21 and 77, there is only a small component, if any, of magnetic forces tending to reopen the by-pass switch. When a blade type of bypass switch is used in this location, there is a tendency to cause such a switch to reopen in response to the magnetic ield established by closing the switch. This matter is of substantial importance in the case of switches carrying high values of current with which are associated strong magnetic elds. Moreover, the inturned ends 33, 33' of the contact members 31, 31 are of a nature that inlflowing current of said inturned ends causes the opposite sides of the inturned portions to tend to spring apart under the magnetic ield thus established. This tends magnetically to drive the Contact buttons 35, 35 into strong engagement with the shoulders 63 and 61, respectively, as the by-pass switch is closed. However, this rad al magnetic effect is not in the axial direction along rod 55, which would tend to open the by-pass switch.

Another advantage of the invention is the construction wherein the switch blades 131 and 151 are separately pivoted and connected by link 163, 165, 167 for conjoint pivoted operation. This is advantageous over constructions wherein the two blades are rigidly related and carried on a single pivot. The present two-pivot construction olers less resistance to opening. Moreover, the prying action afforded by the lever 175 on fulcrum 97 provides a substantial mechanical advantage in starting opening operation of the switch blades 131, 151 from the contacts 93 and 13, respectively, in addition to providing the mechanical advantage for pulling the by- pass switch 57, 35, 35 into closed position. y

Another advantage lies in the insulating properties of the switch. Thus the steatite cup located between the open bottom of the conductive cup 25 and the spool 57 (in the open position of the latter) guards against leakage currents across the open by-pass switch when the main switch blades 131 and 151 are closed. The inverted horseshoe shape of the insulator 69 provides weather protection for the parts of the by-pass switch covered thereby. The resin inlling around the studs in insulators 69 and 113 reduces the effect of shock on the insulators. insulator 153 is ot the strain type and similar resin-inlled threaded connections are preferably used between it and the threaded parts of the clevis members and 167.

4In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. An electric switch comprising spaced rst and second pairs of conductive-members each insulated from the others, switch blades each of which is individually pivoted on and conductively connected with one of the second pair of conductive members, one blade lying over the other for substantially coplanar movements, insulating means operatively pivoted with and connecting said blades for conjoint operation therewith as a pinned linkage wherein the blades move relatively to one another when they pivot, main contacts on the first pair of insulated conductive members adapted to be engaged and disengaged by said switch blades respectively, a by-pass switch having means adapted electrically to disconnect and connect the members of said first pair of conductive members, actuating means between one of said blades and said by-pass switch means forming a driving connection adapted to open the by-pass switch means when the blades are moved toward closed position, and means adapted to force the by-pass switch means into position electrically connecting the members of said rst pair of conductive members when said blades are moved toward open position.

2. An electric switch comprising spaced first and second pairs of conductive members each insulated from the others, a pair of switch blades, each of which is individually pivoted on and conductively connected with a member of the second pair of conductive members, one blade lying over the other, insulating means operatively pivoted with and connecting said blades for conjoint operation as a pinned linkage wherein the blades are relatively movable, main contacts on the rst pair of insulated conductive members adapted to be engaged and disengaged by free end portions of said switch blades respectively, a by-pass switch having a slidable plug adapted electrically to disconnect and connect the members of said iirst pair of conductive members, means between one of said blades and said plug forming a driving connection adapted to open the by-pass switch when the blades are moved toward closed position, and means adapted to force the plug of said by-pass switch into position engaging the members of said first pair of conductive members when said blades are moved toward disconnecting position from said contacts.

3. An electric switch according to claim 2, including a straight-line guide means whereby the movement of the plug occurs substantially along a straight line.

4. An electric switch according to claim 3, including adjacent line terminal extensions from said rst pair of conductive means respectively, the straight-line opening and closing movement of the plug of said by-pass switch aar/oase @i being substantially transverse to the main current paths in said extensions.

5. An electric switch according to claim 4, wherein said switch includes contacts on said insulated conductive members respectively, which contacts comprise conductive members having inturned ends sprung in a direction transverse to the direction of movement of said plug, said ends adapted in response to current iiow therein to be magnetically forced toward the sides of said plug.

6. An electric switch comprising spaced first and second pairs of conductive members each insulated from the others, a pair of switch blades at least one of which is pivoted, said blades being adapted to move together into a switch-closing position in which one blade electrically connects members of the pairs and the other blade connects the other members of the pairs, said blades being movable into a switch-opening position in which said electrically connected members are disconnected, a plug-type by-pass switch having contacts connected to the conductive members of one of said pairs and having a contact plug means guided for sliding Itranslatory movement into and out of engagement with said contacts, said plug means being adapted to be pushed out of engagement with said contacts by at least one of said blades when the blades are moved into switch-closed positions thereof, latch means connecting said last-named blade with the plug means adapted to draw the plug into connected position with said contacts when said blades are moved to switch-open po-sitions, and means adapted to release said latch means when the plug engages its contacts and said blades continue their opening movements.

7. An electric switch according to claim 6, wherein both of said blades are pivoted for motion in substantially the same plane and are connected by an insulating drag link, one or said blades being shorter than the other and swingable under said slidable plug and the other blade being longer and having its end swingable adjacent the one end of said slidable plug in the region of said latch means between them.

8. An electric switch comprising spaced first and second pairs of conductive members forming line terminals, each of which members is insulated from all the others, switch blades pivoted and in conductive connection with the members respectively of the second pair of conductive members, an insulating driving link pivoted to and connecting said blades, main switch contacts on the irst pair of insulated conductive members adapted to be engaged and disengaged by Said pivoted switch blades respectively, a by-pass switch having by-pass contacts on said rst pair of conductive members respectively and having a plug mounted for translatory slidable movement adapted to disconnect and connect said by-pass contacts, said by-pass switch having an insulated operating member connected With the plug, releasable connecting means between one of said blades and said operating member forming a driving connection therewith and adapted to open the by-pass switch When the main blades are moved to a position connecting with said main switch contacts, said releasable connecting means being adapted to draw the plug of said by-pass switch into position electrically connecting the by-pass contacts when said blades are moved into disconnecting position from said main switch contacts, means adapted upon further opening movement of said blades to release said connecting means, and an insulator mechanically connecting the iirst pair of conductive members and forming a cover for the movable plug or" the by-pass switch.

9. An electric switch according to claim 8, wherein the contacts of said by-pass switch are located in conductive cups under the cover provided by said insulator.

10. An electric switch according to claim 9, wherein one of said cups has an opening adapted to accommodate outward movement of the plug when the by-pass switch is open, and including an insulating cup in the opening and surrounding the portions of said plug which l@ extend from said opening, whereby are minimized the leakage currents across the by-pass switch when it is open.

1l. An electric switch comprising spaced first and second pairs of conductive members forming line terminals, each of which members is insulated from all the others, switch blades pivoted and in conductive connection with the members respectively of the second pair of conductive members, an insulating driving link pivoted to and connecting said blades, main switch contacts on the first pair of insulated conductive members adapted to be engaged and disengaged by said pivoted switch blades respectively, a by-pass switch having by-pass contacts on said rst pair of conductive members respectively and having a plug mounted for translatory slidable movement adapted to disconnect and connect said by-pass contacts, said by-pass switch having an insulated operating member connected with the plug, releasable connecting means between one of said blades and said operating member forming a driving connection therewith and adapted to open the by-pass switch when the main blades are moved to a position connecting with said main switch contacts, said releasable connecting means being adapted to draw the plug of said by-pass switch into position electrically connecting the by-pass contacts when said blades are moved into disconnecting position from said main switch contacts, and means adapted upon further opening movement of said blades to release said connecting means, said by-pass contacts being arranged in radially movable circularly disposed groups around the axis of movement of the plug, and said plug being of spool form adapted to have endwise portions thereof move within said circularly disposed groups of contacts respectively.

12. An electric switch comprising spaced iirst and second pairs of conductive members each insulated from the other, a pair of switch blades, at least one of which is pivoted, said blades being adapted to move together into a switch-closing position in which one blade electrically connects members of the pairs and the other blade connects the other members of the pairs, said blades being movable into a switch-opening position in which said electrically connected members are disconnected, a by-pass switch having groups of circularly disposed resilient contacts the members of each circularly disposed group of which are in opposed relationship to one another, the groups' being connected to the conductive members respectively of one of said pairs, an axially movable conductive spool having conductive flanges, said spool being guided for movement of said conductive anges into and out of engagement with surrounding members of said groups of contacts respectively, driving means between said spool and at least one of said blades adapted to move said spool axially to push said anges out of engagement with said contacts upon movement of said blades when the blades are moved into switch-closed positions thereof, and means adapted axially to drive the spool to force the anges into connected position with said contacts when the blades are moved to switch-open positions.

13. An electric switch comprising spaced rst and second pairs of conductive members each insulated from the other, a pair of switch blades, at least one of which is pivoted, said blades being adapted to move together into a switch-closing position in which one blade electrically connects members of the pairs and the other blade connects the other members of the pairs, said blades being movable into a switch-opening position in which said electrically connected members are disconnected, a by-pass switch having spaced groups of circularly disposed resilient contacts connected to the conductive members respectively of one of said pairs, an axially movable conductive spool having radial conductive anges, said spool being axially guided for substantially straight-line movement of its anges -into and out of engagement with each of said groups of contacts, said spool being adapted to be pushed to move its flanges out of engagement with said contacts by at least one of said blades when the blades are moved into switchclosed positions thereof, spring means axially disposed relative to the spool adapted to bias it toward engagement of its flanges with said contacts when the switch blades are moved to switch-open positions, and latch means adapted when the switch blades are in switchclosed positions to lock them in closed positions to maintain said spool in position to disengage its flanges from said contacts against the action of said spring means.

14. An electric switch comprising a support, spaced first and second pairs of conductive members on said support each insulated from the other, a pair of switch blades, one blade lying over and having an extension beyond the other at least one of which blades is pivoted, said blades being adapted for coplanar movements into a switch-closing position in which one blade electrically connects members of the pairs and the other blade connects the other members of the pairs, said blades being movabie into. a switch-opening position in which said conductive members are disconnected, a by-pass switch having two gronps of circularly disposed contacts, said groups being connected respectively to conductive members of said first pair opposite said extension, said bypass switch having an axially movable Conductive spool carrying flanges for movement into and out of engagement with said groups of contacts, said contacts of each group springingly engaging said flanges in a direction transverse to spool movements, said spool being adapted to be pushed out of engagement with said contacts by means connected with said blade extension when the blades are moved into switch-closed positions thereof, latch means connected with said extension adapted to pull the spool into engagement of its anges with said contacts when the switch blades are moved to switchopen positions, a rocker connected with said extension adapted when pulled temporarily to react relative to the support strongly to force the blades to open positions and the by-pass switch to closed position, said lever after said temporary action being adapted to release said latch means to disconnect said blades from the by-pass switch as the blades move further to open positions while the by-pass switch remains closed.

15. An electric switch comprising spaced first and second pairs of conductive members forming line terminals,

each of which members is insulated from all the others, switch blades pivoted and in conductive connection with the members respectively of the second pair of conductive i embers, one blade lying over and having an extension beyond the other, an insulating driving link pivoted to connecting said blades, main switch contacts on the first pair of insulated conductive members adapted to be engaged and disengaged by said pivoted ch blades respectively, a by-pass switch having circularly disposed groups of by-pass contacts on the conductive members respectively o said iirst pair and having a conductive spool mounted for translatory axial slidabie movement and having iianges adapted to disconnect and connect said by-pass contacts, said by-pass switch having an insulated operating member connected with the spool, releasable connecting means between said blade extension and said insulated operating member forming a driving connection therewith and adapted to a'ially drive the spool to open the by-pass switch when the main blades are moved to a position connecting with said main switch contacts, said releasable connecting means being adapted to draw the spool of said by-pass switch into position electrically to connect its flanges with the bypass contacts when said blades are moved into disconnecting position from said main switch contacts, a fulcrum, and a rocker pivoted to one of the switch blades adapted to be engaged by an operating tool, said rocher including a lever engageable with the fulcrum and adapted thereby to pry the switch blades toward open position and to force the by-pass switch toward closed position upon initial opening movements of the blades.

16. An electric switch according to claim 15, including lost-motion connecting means between said rocker and said releasable connecting means adapted to effect release after said prying action has been substantially completed.

17. An electric switch according to claim 16, including latch means adapted to latch one of said blades to one of said first pair of conductive members when the blades are in closed position and adapted to be unlatched by movement of said rocker before initiation of said prying action.

Goldner Apr. 22, 1941 Ortwig Mar. 24, 1959

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