US1541363A - Electric switch - Google Patents

Description

June 9, 1925. 1,541,363

A. y R. LOCKE ELECTRIC SWITCH Filledv May 21, 1921 5 Sheets-Sheet 1k A. R, LocKE ELECTRIC SWITCH June 9, 1925.

Patented June 9, 1925.

lPATENT i OFFICE.

ALBERT B. LOCK'E, OF CHICAGO, ILLINOIS.

ELECTRIC SWITCH.

Application filed lay 21,

To all whom it may concern Be it known that I ALBERT R. LOCKE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

This invention relates to electric switches.

It will be explained as ap lied to a switch for switchboard use althoug it, may be employed in various other fields and on other fixtures.

One of the objects of the invention is to provide an improved switch.

Another object is to provide an improved knife switchy whose movable contact is normally biased to mid-position and 4firmly held in its extreme positions without dependence upon the frictonal or spring ac tion of the contacts.

Another object is to provide a switch which may be secured in position without the use of extraneous fasteners suoli as bolts, screws and the like.

Another object is to provide a switch which is automatically and quickly operated from extreme to mid-positions after the operation is initiated.

Another object is to provide a, switch which may be readily and quickly installed and removed.

Another object is to provide a switch which may be selectively controlled in ups or n grlnothergbbct is to provide a. switch which is neat in appearance, inexpensive to manufacture, and reliable and efficient in operation.

Other objects and advantages will here# inafter appear.

Embodiments of the invention are illustrnted in the accompanying drawings.

The views in the drawings are as follows:

Fig. 1 is a horizontal central section through one form of switch in position on a switchboard.

Fig. 2 is a vertical central section thereof. Fig. 3 is a section on the line 3 3 of Fig. 2.

Fig. 4 is a section on the line 4 4 of Fig. 1.

Fig. 5 is a section on the line 5--5 of F 2. i lFig. 6 is a horizontal central section of 1921. Serial No. 471,339.

a modified switch particularly adapted for selective group or gang control.

Fig. 7 is a vertical section through the modified switch in selected condition.

.Fig 8 is a, section on the line 8-8 of Fig.

Fig. 9 is a vertical section through the modified switch in non-selected condition.

Fig. 10 is a side view of the modified switch in one of its extreme positions.

Fi 11 is a front elevation of a switchboar equipped with the improved switch and .adapted for selected group control, and

12 is a section on the line 12-12 o igs. 1 to 5 will first be described.

. The switch is shown mounted u n a switchboard of the so-called dead front type. Such switchboards ordinarily have a back board or panel 1 of suitable insuf lating material and a front plate or panel 2 of metal. The back board carries the fixed switch contacts and terminals while.

the f ront plate is insulated therefromv and 1s primari y for the purpose of protecti the operator from coming in contact wirt the live parts.

The improved switch comprises, in general, two alternate sets of fixed contacts 3 and 4, a. movable contact 5, a support 6, and an operating handle 7. The support comprises a cylindrical member 8 provided at its rear end with a diametrical slot 9. The forward end of member 8 is of smaller diameter than the rear end, to form an annular shoulder 10, vand is exteriorly threaded. The forward end is also provided with an open ended substantially hemispherically bottomed cylindrical chamber 11. Slot 9 extends into or communicates with chamber 11.

The decreased diameter and internal chamber cause the forward end of the support to take the form of a projecting ring 12. The forward edge of ring 12 is provided with two diametrically positioned notches 13. Notches 13 extend throu h the rim of ring 12 in a direction at rig t angles to slot 9.

Secured to handle 7 is an actuator 14, having a substantially spherical head which movably fits within chamber 11 Vof the support. The head of the actuator is rovided with a hole 15 which extends axially rear end of the sup ispher'ical bottom o the cham r thereof,`

from its base to a point above the center thereof. The head also has a small pivot hole extending therethrough at its'center and at right angles to hole 15. The pivot hole receives a ivot pin 16. The actuator is pivoted slig tly eccentric. This construction may be secured by the hole 15 and, if desired, by flattening slightly the bottom of the head about hole 15.

The movable contact of the switch includes a flat blade 17 pivotally connected to actuator 14 by pin 16. Blade 17 may be made of suitable metal such as steel or 1ron. The blade does not carry current so that the conducting properties of the metal vcomposing the same is of no importance. The rear end of blade 17 is slotted to receive and hold a screw 18. An insulating bushing 19, having a cylindrical hole therein, ts upon the end of blade 17 and is held in place by a nut 2O which threads upon screw 18. Bushing 19 carries a metallic ferrule or sleeve 21 which may be secured theretoin any suitable manner, such for example, as by spinning the end thereof into .the bushing. i The portion of ferrule 21 which is principally dependedupon for carrying the current between the set of fixed contacts, is back of the left hand or rear edge thereof. The rear edge, however, is the first and last point to meet and leave the fixed contacts. Therefore, in additionA to obtaining a good wiping contact, the int where arcing is most apt to occur 1s not depended upon primarily to carry the current. The usual pitting and burning of the movable contact with accompan ing poor electrical conductivity is thus e 'l ated from the main current carrying portion andis thus rendered largely unobjectionable. The ferrule is also readily rotatable so that different parts of its surface may be brought into engagement with the fixed contacts.

Fei-rule 21, when the switch blade is in either of its extreme positions, is forced between the set of xed contacts 3 or respectively. Thus the respective set of ed contacts is electrically interconnected by the conducting errule of the movable contact.

The actuator, and consequently the` movable contact and handle are biased to mid position and firmly held in eitherl extreme position by a pair of spring pressed lungers 22. These plungers are centaine within two small holes which extend from the rt throu h the hemone on each side of slot 9. Each plunger is yieldingly forced against the spherical head of actuator 14 by a spring 23.` The rear of the plunger holes are closed and the tension of the springs may be regulated by' adusting screws 24.

lade 17 is further held in mid-position and also in both extreme positions bynwo sets of balls 25 and 26, respectively. ese balls are each retained in a hole which extends through member 8 and opens into slot 9. The balls are pressed inwardly toward the slot by springs 27. Springs 27 are retained in place by threaded adjusting screw plugs 28. The distance between the sets or pairs of oppositely positioned balls is such that when blade 17 is in mid-position the balls of each pair bear respectivel a ainst the upper and lower edges of t e lade. Thus when the blade is moved toward either of its extreme positions sufiicient force must be exerted to push inwardly either the upper or the lower set of balls. The balls therefore hold the switch blade and handle in mid-position. When the blade is moved to one of its extreme positions, where the contact carried thereby interconnects one/of the pairs of fixed contacts, either the lower or upper set of balls lies back of the opposite edge of the blade holdin the vsame in extreme position. To move t e blade from extreme position sufficient force must be used to depress the balls so that the blade may be moved over them. Thus the balls snap behind the edges of the switch blade and assist in holding the same against premature movement, either from mid-position or extreme position.

The support is held to the front plate of the switchboard and the actuator and blade are held to the support by an internally threaded nipple 29. This nipple screws upon the threaded ring 12 of the support, clamping the front late against shoulder 10 and closing the pivot notches in ring 12 so that the actuator is firmly held in the support chamber.

The circular projecting ring of the switch support permits the drilling of circular holes in the front plate of the switchboard andthe holding n1 ple firmly secures the switch together an to the switchboard in an exceedingly simple and attractive manner. The handle is pivoted in or in front of the plane of the front panel which need not be slotted to-allow for the movement of the handle.

If it is desired to more iirmly secure the switch to the switchboard L shaped supporting feet 30may be rovided. These feet may be screwed or bo ted to sup lort 8 and the backboard, or they may be ormed inte rally with the support.

he operation of the switch is briefly as follows:

Normally the handle and movable blade stand in mid-position, as shown in the drawing. Neither set of `fixed contacts is interconnected and the switch is o n. The blade and handle are yield-ingly he d in mid-posi-A llO actuator and by the spring pressed balls acting against the upper and lower edges of the blade.

To close the switch through the upper or lower set of fixed contacts the handle is moved respectively downwardly or upwardly. As the head of the actuator is moved aboutits axis the eccentric pivoting thereof and the pressing back of the balls by the blade cause enough resistance to this movement to insure smooth and positive operation. Also, in case the handle should be released, the actuator, blade and handle will be returned automatically to mid-position where the exterior surface of the spherical head is nearest to the pivotal axis. wW'hen the handle is moved to such an extent that the spherical surface engaged by the plungers is again nearer the axis and the upper or lower pair of balls are back of the opposite edge of the blade, the force of the plungers and balls holds the handle, actuator and blade in this position. The fixed contacts are so related tothe movable contact that in f this condition the movable contact has been forced between one of the sets of fixed contacts interconnecting the same and completing the circuit. The retention of the switch in closed position is, therefore, inde- :io pendent of the frictional or spring engagement of the fixed and movable or current carrying contacts.

To open the switch it is onlynecessary to move the handle through an exceedingly :i5 small distance (only suicient to move the spherical head of the actuator so that the curved ,cam acting surface thereof begins to allow the plungers to rise and the edge is ast the pair of balls which have been be- |0 iiind the same), whereu on the' spring ressed plungers automatlcally force the iiandle, actuator and blade to mid-position.

Figs. 6 to 10,v inclusive, show a switch embodying the same principles and adapted l5 for selective group or gang operation.

The switch has a slotted cylindrical support containing an actuator 36 pivoted thereto 'by a pin 37. The support contains a pair of spring ressed plungers 38 and 39 50 which act upon t e head of actuator 36 and two pairsof spring pressed balls 40 and 41 which act upon the switch blade. The actuator has an operating handle 42 secured thereto. A threaded nipple 43 holds the 55 support to the switchboard and the actuator to the sup ort. The foregoing structure is substantialiy the same as that hereinbefore described and functions in the same manner.

A movable blade 44, carryinga movable contact 45 similar to that reviously deribed is held in a hole in t e head of actuator 36 by pin 37 as in the previously described structure. Blade 44, however, in- 05 stead of being formed ofa single strip is which extends thru an axial hole in handle 42. The hole in the handle is enlarged to form a cylindrical spring chamber in which is a spring 51. A selecting button 52 is secured to extension so that it may be freely rotated thereupon but longitudinal movement of the button moves the selecting plunger longitudinally. Spring 51, bearing against the bottom 0f the hole in handle 42, and against the base of button 52, biases the button toward its outermost position, as shown in Fig. 9. The button and plunger, however, may be moved and retained in their innermost position by a pin 53 on the button and a bayonet slot 54 in the handle. lVhen the button is forced in against the pressure of spring 51 and given a slight amount of rotation determined by the pin and slot, the button and selecting plunger are held in this position until the button is turnedso that the pin is released.

VThe rear end of plunger 48 is pointed and lies between two pawls or dogs 55 and 56. Pawls 55 and 56 lie between strips 46 and 47 composing compound switch blade 44 and are pivoted thereto by pins 57 and 58, respectively. The front ends of pawls 55 and 56 are biased together by a spring 59. When button 52 and selecting plunger 48 are in outward position, as shown in Fig. 9, the two pawls are biased by spring 59 to assume a substantially parallel position, wherein neither materially projects beyond the edges of blade 44. When button 52 is forced in, the point of plungerv 48 separates the forward ends of pawls 55 and 56 against the force of spring 59 and holds the same in this position with the forward ends of the pawls projecting slight-ly beyond edges of blade 44 as shown in Figs. 7 and 10.

In the extreme positionof blade 44 and handle 42 movable contact 45 bridges and interconnects sets or .pairs of stationary contacts 60 or 61, respectively.

A trip rod 62, having a pair of trip pins or arms 63 and 64 for each switch, cooperates with pawls 55 and 56 to cause the switch blade to move from either xed position to mid-position. When button 52 is forced in to separate the front ends of pawls 55 and 56, as shown in Figs. 7 and 10, the front ends of these pawls are in the path ofarm 63 or 64, de nding upon whether the switch handle and lblade are in one extreme position or the other. Thus, if as shown by the full lines of Fig. 10, the handle is down and the blade and movable contact up, the front end of pawl B5-is in the path of arm 63 when trip rod 62 is depressed. On the other hand, if the handle is up and the blade and movable Contact down, as shown by the dotted lines, then pawl 56 is in the path of arm 64 when trip rod 62 is elevated. When 'the selecting button 'and plunger are out the pawls are not in the path of either arm 63 or 64 in" either extreme position of the handle and switch blade.

vConsequently when the selecting button is in and the switch is moved to either extreme position the up and down movement o-trip rod 62 will cause the arm thereon to engage the projecting ends of the pawls and trip the switch which will be moved to mid-position by its spring pressed plungers. lVhen the button is out the movement of the trip `rod does not aiiect the switch.

Figs. 11 and l2 diagrammatically.showv how the switches may be controlled by groups.

The switchesin the right'had row are designated A, B, C, D, E and F, respectively, and since all of the rows may be similarly controlled, this row is chosen to illustrate the selective operation,...

The trip `rod is shown extending the height of the switchboard and biased to mid-posi.- tion by two opposing springs 65 and 66. A pivoted lever 67 is connected to trip rod and may be operated either to elevate or depress the same.

Switch A has-its selecting button out and its handle moved to close the upper step of contacts 60. Switches B and D are in midposition. Switches C and F have their selecting buttons in and their handle depressed.

to close the upper set of contacts GO. Switch E has its button in and its handle thrown to close the lower set of contacts 61. Thus the I' in a predetermined manner. If trip lever operations may be setup and tripped as i sult is to provide a pair of master trip bars 67 is raised switch E will be caused to open.- `No eii'ect will be vexerted upon the other switches. If .the trip ylever is depressed switches C and F will be caused to open. Switch A, however, since its button is out is unatl'ected. .Any other combination of desired. Y

All of the trip rods may be controlled ltogether by providing means for simultaneously throwing all of the -trip levers'. One arrangement for accomplishing this re- 68 and 69 which extend' alongthe switchboard and respectives? o of the trip levers. ving the master trip ator above and vbelow -all bars in one direction elevates all of the trip levers while moving the same in the other direction de resses all of the tri levers. The switc es may be connecte to circuits as desired and by the selective operation of the same the circuits may be closed in various groups. By resetting the selectin plungers the switclies may be tripped and the circuits opened in any desired group arrangement without aiecting those switches and circuits which should remain closed. The selecting buttons give ready visual indications of the setting of the switches so that an o erator can tell at a lance which switc es will be open and w ich switches will remain closed upon the next operation of the trip lever.

Having described my invention what I `claim as new and desire to secure by Letters support being slottedA at its rear end andr screw threaded at its' forward end, an actupivotally connected to the support, a mova le contact carried by the actuator, a spring pressed plun er acting upon the actuator, and a threa ed collar for attachlment tothe threaded end of the support and acting to hold the support to a fixture and'to secure the actuator to the support.

3. An electric switch having a support with a threaded forward end for insertion through the .wall of a fixture, a switch blade pivotally associated with the support and having an operating handle, anda threaded nipple for clamping the support to a fixture and securing the switch bla e to the support.

4. A switch having a support for attachment to a switchboard, a contact carryin` blade ivotally mounted on the suplport, anc capab e of being moved toa norma pos1tiou and an extreme position, a handle for actuating the blade, a pair of pawls pivoted 'to the blade i and movable 'to operating and non-operating position, a selector for controlling the4 position of the pawls, and means `for cooperating with the pawls in operating position tofcause the blade to be moved irom extreme to normal positions.

In' testimony scribedmy name.

- ALBERT R. LOCKE.

whereof I hereunto l sub-V

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