US2542530A - Switch - Google Patents

Description

Feb. 20, 1951 JEFFREY 1 2,542,530

SWITCH Filed July 1, 1944 5 Sheet-Sheet 1 IN I 'ENTOR.

MAXLJEFFREY ATTOPN E Y5 Feb. 20, 1951 M. L. JEFFREY SWITCH Filed July 1, 1944 5 Sheets-Sheet 2 bid "*4 7 Hil INVLN TOR. v M4 X. LJ'EFFREY r) TTORNE Y5 Feb. 20, 1951 INVENTOR.

MAXI. JEFFRE Y ATTGQ/YEYE Feb. 20, 1951 I M. L. JEFFREY 2,542,530

SWITCH Filed July 1, 1944 5 Sheets$heet 4 jj I78 9 W mum E: 9

V 5 INVENTOR.

MAXI. JEFFREY 54 BY ,4 TTOPNEY Feb. 20, 1951 M. L. JEFFREY 2,542,530

SWITCH Filed July 1, 1944 5 Sheets-Sheet 5 AL OVERLDAD CUTOUT ACBPHASE POWER LINE INVENTOR. T MAXLJfl-FREY a MW A TTORNE Y5.

Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE SWITCH Max Leroy Jeilrey, Shaker Heights, Ohio, assig-nor to The National Acme Company, Cleveland. Ohio, a corporation of Ohio Application July 1, 1944, Serial No. 543,114 10 Claims. (Cl. 200-116) This invention relates to switches and more particularly to a multi-pole switch having a quick make and break and also having provisions for opening the circuit upon an overload thereof.

One of the objects of my invention is to provide a switch of the multi-poie type where arcing is reduced to a minimum by a quick make and break mechanism.

Another object of my invention is to provide a switch wherein means is incorporated to cause the contacts to open when the circuit being controlled is overloaded.

Another object of my invention is to provide an improved overload releasing device.

Another object of my invention is to provide an improved thermostatically operated overload device.

Another object of my invention is to provide a switch which may be closed in an emergency in spite of the fact that the overload protection means has operated and the switch under such conditions is normally open.

Another object of my invention is to provide a switch mechanism capable of carrying high currents and yet wherein the space requirements for such a device are reduced to a. minimum.

Another object of my invention is to provide a switch mechanism wherein the operating parts are enclosed in a water tight explosion proof housing.

Another object of my invention is to provide a switch which is adjusted for mounting in various positions, and which thus lends itself to mounting on and use with various types of mechanisms. 7

Other objects of the invention reside in economies in manufacture and the organization and arrangement of the parts such that adjustments, repairs and replacements may quickly and easily be made without the need of special tools or equipment.

Still other objects of the invention and the invention itself will become more apparent from the following description of an embodiment thereof and which description is illustrated by the accompanying drawings and forms a part of this specification.

In the drawings:

Fig. 1 is a top plan view of the exterior of the device;

Fig. 2 is an end elevational view thereof Fig. 3 is a plan view of the switch with the cover removed;

Fig. 4 is a vertical section taken on the line 4-4 of Fig. 3;

Fig. 4a is a similar view taken on the lines la4a of Fig. 3;

Fig. 5 is a vertical section as indicated by the lines 5-4 of Fig. 3 through the housing for the switch, the interior mechanism being shown in side elevation;

Fig. 6 is a sectional view taken from a plane indicated by the lines 6-8 of Fig. 5:

Fig. 7 is a top plan view of the contactor drum assembly removed from the switch;

Fig. 8 is a side elevational view thereof:

Fig. 9 is an end elevational view thereof taken from a plane indicated by the line 9-9 of Fig. 8;

Fig. 10 is a section taken on the line lO-lil of Fig. 8;

Fig. 11 is a fragmentary view, through the center of the switch with certain parts shown in e evation and with other parts broken away and shown in section, and particularly illustrates the clutch mechanism and its manner of connecting the snap mechanism to the contactor drum as well as the overload releasing thermostat;

Fig. 12 is a vertical section taken from a plane indicated by the line l2-l2 of Fig. 11;

Fig. 13 is a rear elevational view of the snap mec anism housing assembly;

Fig. 14 is a side elevational view of one of the clutch levers;

Fig. 15 is a front view thereof;

Fig. 16 is a side e'evaiional view of a clutch lever which cooperat s with that of Fig. 14;

Fig. 17 is a rear view thereof;

Fig. 18 is a view of the contactor drum operating lever taken from the side which is disposed adiacent the end of the contactor drum;

Fig. 19 is an opposite face view thereof with a portion broken away and s own in section;

. Fig. 20 is a top p an view thereof;

Fig. 21 is a si e elevationalview thereof;

Fig. 22 is a side elevational view of the thermostat element r moved from the device;

Fig. 23 is a front view thereof;

Fig. 24 is a deve o ed view of the thermostat heater element assembly;

Fig. 25 is an end elevational view of one of the heating elements;

Fig. 26 is a circuit dia ram showing one mann r in which connections to the de ice for controlling' a three-phase circuit may be made;

Fig. 2'1 is an end view of the contactor drum supporting bracket;

Fi 28 is an exnloded view of the heater eleme t ass mbly; and

Fig. 29 is a side e evational view of one of the fixed contact carrying blocks, removed from the ass mbly.

Referring now to the drawings throughout which like Darts have been designat d bv like reference characters, and first particularly to Figs. 1 and 2, I have illustrated a housing which comprises a b se housing "I and a cover housing II. The base com rises a substantially rectangular bottom portion l2 which is provided with op nings l3 through which studs may extend and by means of which it may bemounted as desired. The housing I0 is provided with walls which rise from the bottom portion spaced I 3 from the ends and is contoured to receive the mechanism hereinafter described. The end walls of the housing are formed to provide internally threaded hollow bosses is which provide for coupling to a conduit pipe not shown and through which connecting wires, omitted in the interest of clarity of description, may extend for connection to the switch terminals. The upper portion of the base housing terminates in a flange It the upper surface of which is ground flat and adapted to receive the cover ii. The cover II is likewise provided with a lower flange ll having a face corresponding with that of the flange It. Screws It extend through openings in the cover flange ll and into threaded openings in the flange It for holding the cover seated on the base. The faces of the flanges It and I! provide a close flt rendering the same substantially fluid tight and in addition thereto the inner wall of the cover, as can best be seen in Fig. 6, is displaced inwardly relative to the inner wall of the base and a groove is is provided in the flan e ll which groove is spaced from the edges of the flange and overhangs the wall of the lower housing. A gasket of rubber or similar material is disposed in this groove and when the cover is placed on the base this gasket is'compressed by the upper inner edge of the lower housing to provide a further effective seal. The upper and lower hou ing parts are thus effectively sealed to each other in fluid, gas and air tight engagement.

The cover besides acting as a cover for the lower housing, also supports the main operating lever '25 which, as best shown in Figs. 1, 2 and 5, includes a central boss having a bore 20 enabling it to be secured to a shaft 21 and pinned thereto by a taper pin 20. Extending laterally at diamotrically opposite sides from the central boss are portions 29 provided with finger engaging seats which enables the shaft to be rocked by simply pressing down on one end or the other of the lever.

The shaft 21 extends through a bore in the boss 30 in the end ofthe cover, having a close sliding flt therewith, and is provided on its inner end with a cylindrical enlargement II which is transversely slotted adapted for engagement with the snap switch operating mechanism. The end ll fits in an enlarged counterbore 32 and a packing 33 is disposed between the shoulder provided by the cylindrical end and the shaft and the end of the bore. On the outside of the housing and surrounding the bore which receives the shaft 21, there is provided an annular groove 3| which opens toward the enlarged boss It on the lever 25. A helical spring 31 is disposed in the groove being seated in the bottom of the groove and resiliently pressing against the lever 25, pushing the lever outward and holding the inner part 3| in eflective sealing engagement with the gasket or packing 33.

An emergency clutch operating pin extends from the rear of the raised portion ll of the cover, which raised portion is provided to house the snap switch operating mechanism and the thermostat control. This raised portion is provided with a vertically extending wall 42, at the.

rear, that has a bos 43 in its upper part. The boss is provided with a bore 44 for slidably receiving the stem 48 of the pin 40. A counterbore 48 is provided around the stem and houses a hellcal spring ll that has one end seated against the end of the bore and the other end in engagement with the inner end of the head of the pin 4 ll which head extends beyond the confines of the housing. The other end of the lever extends inside the housing and is provided with an inner head ll riveted to the endof the stem. A packing washer 4! is provided between the inner head ll and the end wall of the housing. The spring 41 normally urges the'lever in an outward direction with the packing washer in sealing engagement with the inner head and end It will thus be seen that provision is made for effectively sealing all operating levers extending into or out of the housing as well as the housing itself to assure an effective seal against the admission of gases, liquids or the like, and prevents accidental ignition of volatile gas by sparking of the contacts during operation of the device.

Generally speaking the switch mechanism in the housing constitutes a rotary drum which carries the switch contacts. This drum is spring biased to normally hold the contacts in open circuit position. A snap action mechanism is provided for quickly rotating the drum and its contacts, and a clutch mechanism connects the snap mechanism to the contact drum. A thermostat is provided for disengaging the clutch should the circuit under control become ever loaded.

The snap action mechanism in many respec is similar to that disclosed in my Patent No. 2,- 294,559 of September 1, 1942. It comprises a housing It the formation of which can be best seen in Figs. Band 13, the forward side of which is closed by a plate 5| held onto the face of the housing by screws 52 which extend through the plate into bosses 51 formed in the housing side walls. A pair of laterally extending lugs I are provided on the side walls near the lower end of the housing, the lugs being strengthened by webs 55 slanting upward as best viewed in Fig. 6, and the snap mechanism housing is supported in the lower housing Iii by these lugs which are seated on bosses it formed integral with the sides and bottom of the housing- III. Screws I! extend through holes in the lugs and are threaded into the bosses it. The mechanism is thus supported in an upright position in the housing and extends vertically upward to a point spaced from the underside of the cover.

A lever 0 is pivotally journalled in the upper apex of the housing 60 being secured on a shaft if by a tapered pin 62. The shaft in turn has the one end journalled in the rear wall of the housing 50 (Fig. 13) and the other end is provided with an enlarged circular head 63 which is journalled in an opening in the cover plate ii and is provided with a substantially rectangular lug 04 which extends transversely across the head 83 and protrudes forward from the cover pfate. This lug is adapted to be interlocked with the slotted head if of the manually operated shaft 21. Driving connection is thus effected from the lever 25 thru the shaft 21, head 3| and lug 64 to the shaft BI; and the lever 00 may thus be swung by moving the lever II. A rock lever 68 is provided, being carried on a shaft 61 and locked thereto by a taper pin it. The shaft 81 is Journalled in a bearing 89 in the rear housing wall and the other end of the shaft is Journalled in a bearing Ill in the cover 5i, as can best be seen in Fig. 11. The end of the shaft 61 extends through the rear end of the housin and has integral therewith a part of the clutch mechanism hereinafter more fully described.

As best shown in Fig. 6 the lever 30 is provided with a roller I2 carried by a slide I3 which roller is held in spring pressed engagement with the face of the rocker 60 by a spring I5 disposed in a bore in the lever 00. The rocker is adapted to be rocked by the lever 60 when it is swung from one side of the housing to the other. Movement of the rocker is restrained by a pair of pawls 'I'I journalled on pins 18 disposed spaced from and below the rocker axis at opposite sides of the housing. These pawls are held in spring pressed engagement with the opposite ends of the rocker by spring I9 each of which is disposed over a pin 00 riveted in the side wall of the housing with the other end seated in a recess 0| in the pawl. Each pawl on the sides facin toward the rocker is provided with two rocker engaging stops 02 and 83. The stop 02 limits the movement of the rocker after it is released from the stop 03 and the stop 03 holds the rocker against movement until the side of the lever 60 engages the lug 84 which is disposed on the end of the pawl. The operation is the same as described in the aforesaid patent; that is, when the lever is rocked from the position shown in Fig. 6 to the opposite side, the roller rolls up the inclined face of the rocker. The roller 12 and its supporting slide are forced upward in the lever, compressing the spring 15. The spring pressure increases and the roller presses harder against the rocker as it travels upward over the roller. The rocker in the meantime is held against rocking since the end of the rocker is in engagement with the stop or shoulder 03 on the pawl 11. As the roller approaches the end of the rocker it slides up on the raised portion 85 of the rocker, which causes still greater pressure to be exerted at which time the side of the lever 90 hits the projecting portion or lug 04 of the pawl rotating the pawl against the pressure of the spring 19 and withdrawing the stop 83 from under the end of the rocker. The spring pressed roller then snaps the rocker (in this instance clockwise from the position shown) downward onto the shoulder 02 of the pawl. The movement of the rocker is therefor a quick rotational movement. That is, it is snapped into position. The other pawl then engages the other end of the rocker where it holds it until the lever 00 is moved to the position shown. The movement of the pawls away from the rocker is limited by abutments 01 integral with the sides of the housing.

As previously stated the shaft 61 extends through the bearing 69 in the back wall of the snap mechanism housing and is provided on the rear with one part of the clutch mechanism. As best shown in Figs. 11 and 13 this element constitutes a cup which has a circular body 90 provided with a peripheral flange 9|, and a coaxial stem or stub shaft 92 which extends in alignment with the shaft 31. This shaft provides a support for the clutch parts as well as supporting one end of the rotatable contact carrying drum 93 (Figs. 7 and 8), the other end of the drum being supported in a bearing I3'Ia in a bracket I54 (Fig. 27).

The end of the drum adjacent the clutch is provided with a pair of lugs 95, Figs. 7 and 8, disposed diametrically opposite each other and adapted to engage in recesses 93 in a driven clutch member 91, Figs. 18 to 21, incl.

The driven clutch member includes a circular body having a peripheral flange 90; a central opening 99 being provided through which the stem 92 on the cup body 90 of the other clutch member extends, the driven clutch member being thus supported and the flanges 9| and 00 on the two bodies extending toward each other to provide a chamber or recess therebetween, Fig. 11. The driving clutch flange 9| is provided with a slot I00 and the driven clutch member likewise with a slot I00a, which slots are normally in alignment with each other and provide a space through which the tongues IN and I02 of intermediate clutch levers I03 and I04 may extend.

The driven clutch member 91 is provided with a downwardly extending lug I05 which has a socket I00 formed therein, as best shown in Fig. 19. This socket receives one end of a spring I01 (Fig. 12) the other end of which is adjustably carried by a screw support I08 extended in the wall of the fixed contact carrying support I09 and which may be locked in any desired adjusted position by a lock nut H0. The spring I01 tends to rotate the drum 93, through the member 91 in a direction to normally open the contacts. A stop, which comprises a screw member III having a projection II2 for engagement with the lug I05 is provided, being screwthreaded through the opposite fixed contact carrying member wall III. The stop may be locked in any desired position by the lock nut II3. This stop limits the amount of movement of the member 91 and hence the drum 93. It will be apparent from the foregoing that the driving and driven clutch members are supported in juxtaposed positions to each other. The driving connection therebetween is effected by the intermediate members I03 and I04.

The intermediate clutch member I03 includes a circular body of slightly less diameter than that of the recess formed by the flanges 9I and 98 of the driving and driven clutch members and is provided with a central opening IIB which tapers outwardly at I II. The member is disposed on the stem 92 in the recess between the driving and driven clutch members and because of the tapered opening may tilt therein as can best be seen in Fig. 11. The tongue IOI of the member I03, as previously stated, extends upward through the openings I00-I00a in the flanges 9I--98. The driven clutch member 91 is provided with an aperture IIB which extends through the wall, spaced from the edge and opposite the opening NM. The drum 93 is provided with a recess I IS in alignment with the aperture I I8 and a spring I20 is disposed in the recess and extends out through the aperture H8 and into engagement with the tongue IOI of the member I03 and causes the intermediate clutch lever to be tilted 0n the stub shaft 92 as shown in Fig. 11. The tongue IN is bent slightly at I2I and extends upward opposite the end I22 of the thermostat element I23, the bend I2I permits the tongue to be in parallelism with the thermostat even though the intermediate clutch member is tilted.

The other intermediate clutch member I04 constitutes a circular body which is thinner than the other intermediate clutch member I03. It is also provided with the central opening I25 which is large enough to allow this member also to be tilted, it being supported in like manner on the stem 92 in the recess formed by the driving and driven members, The lower end of the body is provided with a lug I26 which extends toward and is adapted to be in engagement with the body of the member I03. This lug acts as a fulcrum or pivot for the member as will hereinafter more clearly appear. The stem I02 also extends upward from the bodyof this member I I04, through the slots I-'-I00a in the driving and driven clutch member flanges. The stem is provided with a lug I21 which extends toward the other member I and is adapted to seat against the stem IOI of the other member. Above the lug I21 the stem is bent outward at I in a substantially S-shaped curve and terminates in a straight upstanding portion I25 opposite to the other end member or leg III of the thermostat element I22. The cup member 00 is provided with a recess III that carries a spring I52 which bears against the intermediate member I04 tilting it on the stem 52 in a like manner as described for the other intermediate member. Thus the two clutch members are held in engagement with each other. The member I02, because of the thicker body, and the member I04 because of the lug I21, cross themeeting edges of the flanges of the driving or driven members between the flanges lI-Il.

It will thus be seen that in the position shown the drive from the driving member 00 to the driven member 91 is effected by the tongues IOI-I02 of the intermediate clutch members I05--I04 at the openings l00-I00a in the flanges of the driving or driven members. As long as the intermediate members remain tilted, as shown in Fig. 11, the drive connection will remain intact, that is, the lug I21 will be across the Junction of the flanges 0I--08. However, if an overload should occur, the operating legs I22 and I50 oi the thermostatic member, which is bi-metallic in character, will move apart. The leg I will engage the tongue I02 at I25 and the leg I22 will engage the tongue IN and the two intermediate clutch members I00-I04 will be moved from their tilted position to a vertical position, the lug I25 on the member. I04 actin as a fulcrum, and against the pressure of the springs I20I22. In this position the tongues on the intermediate members are no longer opposite the junction of the flanges 0I--55 but are well within the confines of the respective slots I00 and I00a and the driving and driven members are free to operate independently. This action occurs when the switch contacts are in a closed position. this being the position shown in Fig. 12 where the spring I0! is compressing and exerting pressure against the lug I05 of the driven member 81. The current is utilized during overload to heat the thermostat I22, the clutch is released and the spring I01 rotates the drum 92 with its contacts to open position as will be more fully described hereinafter.

It will thus be seen that a drive is eifected from this snap mechanism to the contact carrying drum 92. This drum, as best shown in Figs. '1 to 10, inclusive, comprises a cylindrical body of 8 has an opening I4I therein and apivot pin I42 extends through the opening and provides a support for the contact. The pin I42 extends transinsulating material having the lugs 55 on one end and each end provided with axial bores or recesses I25 and I55. The drum is supported at one end by the stem 02 and at the other end by a pivot pin I21 which is journalled in the opening llla of the bracket I54.

The drum is provided with three transverse openings or channels I20 of rectangular cross section. In each channel there is disposed a contact carrying member I. The members I" are flat metal strips of sumcient length to extend the desired distance beyond the periphery of the drum, and carry on their ends contacts I40. It

will be noted that the contacts. which are riveted in openings near the end of the strip are on upposite faces of the strip. The center of each strip versely across the opening I20 and the ends of the pin are provided with heads I42 which engage the bottom of the counterbores I44 in the drum. Also iournalled on the pins I42 and in engagement with the side wall of the opening are plates or strips I45 each of which has a lug I45 which extends normal to the body of the strip and is adapted to engage the contact carrying strip intermediate its ends and the pivot to provide a flxed stop therefore. The contact carrying strip is held against these stops by springs I 41 disposed on 9. lug on the strip and the other ends of which surround pins on the body of the contact strip. The openings I4 I are large enough so that the strip may tilt freely on its pivot. Normally the contacts are held in the position shown in Fig. 10 but when contact is made the strip may rotate or pivot from the position shown against the pressure of the springs I41. Hence, it will be seen that the drum and contacts are capable of movement relative to each other and that the drum may rotate a certain amount after contact is made. Although I have shown 3 sets of contacts it will be obvious that the number of sets may be increased or decreased without departing from the invention.

The contact carryin drum is rotatable between a pair of blocks each of which carries fixed contacts. These are best shown in Figs. 3, 4 and 40. Each block comprises a member I50 constructed of suitable insulating material of generally rectangular cross section, and which is provided with circumierentialiy extending ribs I5I between which are disposed the contact carrying portions I52. The blocks are supported above the bottom of the lower housing I0 upon bosses integral with the lower housing. The rear end boss is indicated at I52 and carries a bracket I54, Fig. 2'7, which is secured to the top of the boss by a screw I55 which extends through an ear I55 on the bracket into the boss. The blocks are in turn secured to the bracket by strews I51. The front ends of the blocks are supported by the long bolts I58 (Fig. 5) which extcnd through the lower end of the snap mechanism housing and bolts I5Iia directly above as can be seen in Fig. 12.

The contact carrying parts of the blocks have secured thereto general U-shaped cont-act strips III which are held thereon-by screws I52 that extend through the strips and are threaded into bushings I02 molded into the blocks (Fig. 4). The upper end of each strip, which extends horizontal-- ly across the block, is provided with a connecting screw I54 by means of which conductors may be secured in electrical connection to each strip. The end of the strip in the left hand block '(Fig.

4) extends beyond the screw I54 and terminates in an upwardly extending extremity I55 which carries the fixed contact I05. These contacts are so disposed as to make connection with the contacts I40 when the contacts I40 are rotated thereagsinst. The block on the otherside is substantially the same as the other except that the contact carrying strip in this case extends downward at its lower extremity and carries contacts to connect with the contacts on the other end of member I 80.

In Fig. 4a the right hand contact carryin strip is shown as two separate strips with a rib I51 therebetween. In this case the upper strip I50 is L-shaped and carries no contacts and merely serves as a Junction block, while the lower 9 strip is also L-shaped and carries the lower contact I66a'.

The inner faces of the block are provided with semi-circular channels I68 to provide clearance space for the rotatable drum. The drum with its contacts is rotatable between the blocks.

In operation if pressure is exerted on the right hand handle 28 as viewed in Fig. 2, to move it to the position shown. it causes the lever 60 in the snap mechanism to swing to the left (Fig. 6) which rotates the rocker 68 counterclockwise. This motion is communicated through the clutch to the contact carrying drum which causes the rotatable contacts to engage with the fixed contacts completing the circuit. In this position, with the contacts closed the spring I01 is compressed exerting pressure against the arm I05 of the clutch member 81, which pressure, were it not for the clutch mechanism, would open the contacts.

When it is desired to open the circuit the left hand end of the lever 25 is rotated and the contact drum is rotated to the open position.

As previously mentioned means is provided to open the circuit automatically should an overload in the electric circuit occur. This is accomplished by causing the current through the circuit to heat a thermostat unit which disengages the clutch between the driving and driven members after which the spring I01 rotates the drum with the contacts to open position. After the thermostat cools oil the circuit may again be closed by rotating the lever 25 first to the off position, where the clutch elements are interlocked, and then to the on position. Means is also provided in case of emergency so that the contacts can be closed in spite of the overload if desired.

As previously briefly described, the tongues IOI-I82 of the intermediate clutch elements are adapted to be engaged by the ends I22 and I30 of the thermostat to force the clutch elements apart and disengage the clutch.

The thermostat element is supported by a pair of brackets III secured to the top of the snap housing 50 by screws I12. These brackets constitute arms which extend rearward and slightly upward from the housing. The thermostat element per se comprises a pair of bi-metallic strips I18 and I14 bent into circular form as best shown in Fig. 22, the strip I'I3 being disposed inside of and spaced from the strip II4. Interposed between the two thermostatic elements are heating elements I15 and are provided with connectors H6 at the ends. A U-shaped bracket III is soldered or welded to the top of the element, being provided with ears I'I8 which are engaged by screw I18 which extend through the brackets I II into the ears and thus support the same above the clutch tongues with the ends I22 and I30 extending downward between the tongues IIII-I02. In the embodiment shown the end I30 is a separate element welded to the end of the outside thermostat strip H4. The element could all be made in one piece if desired.

A developed view of the heater element is shown in Fig. 24 and it comprises three wide mica strips I8I between which is sandwiched a thin narrow mica strip I82 around which resistance material I88 is wound. The ends of the resistance ribbon may be spot welded to metal connection strips I86 and these in turn have the connectors II6 secured thereto. The strip I82 is held by the connector I86 one end of which is carried around the strip to clamp it.

In this manner the resistance wire is held against uncoiling from around its support and a stable connection for the wires "6 is ailorded.

. The entire resistance element is held assembled by eyelets I84 which extend through all these elements as best shown in Fig. 24. 1

After the heater element is assembled between the two thermostat or bi-metallic elements, the entire assembly is held together by an eyelet or rivet I81 which is inserted through openings intermediate the eyelets I84.

One manner of connecting the switch is shown in Fig. 26 although the invention is not by any means limited to the precise manner shown which is merely for the purpose of explanation and not intended as a limitation upon the invention. Here it is desired to connect a three-phase circuit to a motor. The current is taken from the three-phase power line 200 to the lower contacts I66 the circuits being designated as LI, L2 and L3, through the movable contacts I40 and strips I39 to the upper contacts I6-6a and I66a'; these circuits being designated as MI, M2 and M3. The

circuit from M2 leads directly to the motor. The circuit MI however is connected in series with the H2 which corresponds to the resistance element I83. In this instance two separate heating elements are included in the circuit. From H2 the,

circuit extends back to the junction block I68 and thence to the motor. The other leg of the circuit is from H3 through the resistance element back to the junction block I68 and thence to the motor. It will therefore be noticed that each of the phase windings of the motor is through a heater element. Fig. 28 is an exploded view of a heater element adapted for use in a circuit such as described. Here there is illustrated the resistance or heater elements I82 which are sandwiched between the mica strips I8I. In this instance as indicated in Fig. 26, there are two heater elements, although only one heater element might be desirable in certain instances as where a single phase circuit is being controlled.

Upon a predetermined overload in any part of the circuit, either one or both of the heating elements will, with an increase in current, heat the oi-metallic strips I I3--I'I4 causing them to expand differentially and move the ends I22-I30 apart. This causes the release of the clutch and the opening of the circuit as previously explained.

Normally it takes some time for the thermostat unit to cool on. In some instances it may be desirable or necessary to close the circuit in spite of the fact that the overload is so recent that the bi-metallic strips have not returned to their normal position.

This may be efiected through the emergency operating button 40. The button 40 may be pressed inward against the pressure of the spring 41 until the head 48 engages the end I of a lever IIII, Figs. 5, 11 and 12. The lever I9I, as can best be seen from Figs. 11-12, comprises a substantially fiat member of generally rectangular formation supported between the brackets III by projections I92 which are pivotally 'journalled in holes in the brackets opposite to each other spaced from and behind the snap mechanism housing and between that housing and the thermostat. The lower end of the lever I9I extends forward at I93 in a position adapted for engagement with the tongue I29 on the intermediate clutch element I04. The upper end of the lever extends toward and into alignment with the head 48 on the emergency pin 40.

When the pin 40 is pushed in the head 48 engages the upper end I00 of the lever HI and furassasso ther movement or the pin rotates the lever about the pivots I02 and then forces the lower end into engagement with the tongue I29 and moves the intermediate clutch lever, which is being held in a vertical position by the thermostat, to the position shown in Fig. 11. Just previous to sheeting this action the snap mechanism has been moved to the "oil" position so that the openings ill-Illa in the flanges oi the clutch members are in alignment. This permits the tongue to again elect engagement the clutch as long as the pin 40 is held in place in spite of the fact that the thermostat is attempting to release it. The flexibility oi the thermostat element and the tact that it is pivotally supported at l'ls permits it to be moved without damaging it. After the member I is moved back to its normal position the snap mechanism may again be operated and the circuit will again be remade and will stay remade as long as the operator maintains pressure on the head 40 of the emergency pin.

It will be noted by reference to Fig. 12 that the thermostat element I2! is relatively wide, as is also the release lever Hi to insure alignment with the ends ltl and I29 oi members it! and I through the ranges of rotation of the elements.

It will thus be seen that I have provided a switch mechanism which is compact, utilizing but a small space and capable of being mounted in many positions. Furthermore, the manner of housing the parts is such that it eliminates the hazards of fire and explosion due to arcing inasmuch as no parts are open or exposed.

Furthermore it provides a switch that aflords an exceedingly quick make or break thus decreasing the tendency ior the contacts to arc' with consequent burning of the points regardless of the manner in which the control lever is operated. It has also been shown how the switch automatically opens upon overload and cannot be accidentally reclosed. Also it has been shown how in case of emergency the switch may be operated in spite of the fact that the circuit is overloaded, should it be desirable or necessary.

The construction is such that heavy currents may be handled without the necessity of a large and cumbersome mechanism. The device is also accessible for quick and easy replacement of worn or broken parts.

Having thus described my invention I am aware that numerous and extensive departures may be made therefrom without departing from the spirit or scope of the invention.

I claim:

1. A circuit controller including a stationary contact holder and stationary contacts thereon, a movable contact holder having movable contacts for engaging the fixed contacts to complete a circuit therethrough, means biasing said movable contacts to open position, means for controlling said movable contact holder including a snap action mechanism and a clutch connecting the snap action mechanism to the movable contact holder, means for connection in the circuit to be controlled responsive to overloads in said circuit and connected to said clutch to disengage said clutch, said biasing means adapted to move said movable contacts to open position upon disengagement oi the clutch.

2. A circuit controller including a stationary contact holder and stationary contacts thereon, a movable contact holder having movable contacts ior engaging the fixed contacts to complete a circuit therethrough. spring means biasing said movable contacts to open position, means for moving said movable contact holder including a snap action mechanism and a clutch connecting the snap action mechanism to the movable contact holder, means for connection in the circuit to be controlled, responsive to overloads in said circuit and connected to said clutch to disengage said clutch, said spring biasing means adapted to move said movable contacts to open position upon disengagement oi the clutch.

3. A circuit controller including a stationary contact holder and stationary contacts thereon.

a movable contact holder having movable contacts for engaging the ilxed contacts to complete a circuit therethrough, spring means biasing said movable contacts to open position. means for moving said movable contact holder including a snap action mechanism and a clutch connecting the snap action mechanism to the movable contact holder, means (or connection in the circuit to be controlled responsive to overloads in said circuit and connected to said clutch to disengage said clutch, said spring biasing means adapted to move said movable contacts to open position upon disengagement oi the clutch, and means to overcome said overload responsive means and permit re-engagement oi said clutch and closing of said circuit.

4. A circuit controller including a stationary contact holder and stationary contacts thereon, a movable contact holder having movable contacts for engaging the fixed contacts to complete a circuit therethrough, spring means biasing said movable contacts toward open contact position, means for moving said movable contact holder-including a snap action mechanism and a clutch for connecting the snap action mechanism to the movable contact holder, means for connection in the circuit to be controlled, responsive to overloads in said circuit and connected to said clutch to disengage said clutch upon overload, said spring bias adapted to move said movable contacts to open position upon disengagement oi the clutch, and means to overcome said overload responsive means and permit re-engagement of said clutch and closing said circuit comprising a manually operated lever having a part disposed for engagement with the clutch.

5. An apparatus oi the class described includ-.

ing a housing, an opening in one end of the housing and an operating member extending therethrough, a snap mechanism operable by and controlled by said operating member disposed inside of the housing, a drum type switch, a driven member connected to said switch and a driving member connected to said snap mechanism, said driven member being spring biased to a contact opening position, means connecting said driving and driven members comprising a clutch and means operable upon overload in a circuit being controlled by said switch to open said clutch and disengage said driving and driven members, and auxiliary means to cause re-engagement oi. said clutch during a period of overload.

6. In a switch mechanism of the class described comprising a housing, a pair of supporting members carried by the base of the housing. said supporting members being spaced apart to provide a channel therebetween and stationarif'contacts carried thereby on opposite sides oi said channel, a movable contact c rrying drum supported i'or rotational movement in said channel. contacts carried by said drum for engagement with the stationary contacts, means to rotate said drum comprising a lever disposed outside the housing and a shaft extending in sealed relation through the housing, a snap action mechanism disposed inside the housing connected to and operable by said lever, and means for connecting said snap mechanism to the drum comprising a driving member connected to the snap mechanism and a driven member connected to the drum, said driven and driving members being capable of independent relative movement and means interposed between the driving and driven members to effect drivin relation therebetween and circuit load responsive means for connection to means between the driving and driven members to disconnect said driving and driven members.

7. In a switch mechanism of the class described comprising a housing, a pair of supporting members carried by the base of the housing, said supporting members being spaced apart to provide a channel therebetween and stationary contacts carried thereby on opposite sides of said channel, a movable contact carrying drum sup ported for rotational movement in said channel, contacts carried by said drum for engagement with the stationary contacts, means to rotate said drum comprisin a lever disposed outside the housing and a shaft extending in sealed relation through the housing, a snap action mechanism disposed inside the housin connected to and operable by said lever, and means for connecting said snap mechanism to the drum comprising a driving member connected to the snap mechanism and movable thereby, a driven member connected to the drum, said driven and driving members being capable of independent relative movement and means interposed between the driving and driven members to effect driving relation therebetween and circuit load responsive means for connection to means between the driving and driven members to disconnect said driving and driven members and spring means biasin said drum to a contact opening position and effective upon'disconnection of the driving and driven members to open the contacts.

8. In a switch mechanism of the class described comprising a housing, a pair of supporting members carried by the base of the housing, said supporting members being spaced apart to provide a channel therebetween and stationary contacts carried thereby on opposite sides of said channel, a movable contact carrying drum supported for rotational movement in said channel,

contacts carried by said drum for engagement with the stationary contacts, said movable contacts being supported for movement relative to the drum and spring means biasing the contacts to an inclined position and abutment means to limit the movement thereof, means' to rotate said drum comprising a lever disposed outside the housing and a shaft extending in sealed 'relation through the housing, a snap action mechanism disposed inside the housing connected to and operable by said lever, and means for connecting said snap mechanism to the drum comprising a driving member carried by the snap mechanism and movable thereby, a stub shaft extending from said lever and supporting one end of the drum, a driven member disposed on said stub shaft and connected to the drum, said driven and driving members being capable of independent relative movement and means on said stub shaft interposed between the driving and driven members to effect driving relation therebetween and circuit load responsive means for connection to means between the driving and driven members to disconnect said driving and driven members and spring means biasing said drum to a contact opening position and effective upon disconnection of the driving and driven members to open the contacts.

9. An apparatus of the class described, comprising a housing, a pair of fixed contact carrying blocks secured in the housing and formed to provide a channel therebetween, a movable contact carrying drum rotatably supported in said housing between said fixed contact carrying blocks, means to rotate said drum to cause engagement and dis-engagement of the contacts comprising a driven member connected to the drum and spring means biasing said member to a contact opening position, means for operating the driven member comprising a snap action mechanism disposed in the housing at one end of said fixed contact carrying blocks, a driving member carried thereby juxtaposed to said driven member and means interposed between said driving and driven member to connect said members to each other, spring means to maintain said connection and thermally responsive means to break said connection, said biasing means adapted to open said contacts when the thermally responsive means operates.

' 10. An apparatus of the class described, comprising a. housing, a pair of fixed contact carrying blocks secured in the housing and formed to provide a channel therebetween, a movable contact carrying drum rotatably supported in said housing between said fixed contact carrying blocks, means to rotate said drum to cause engagement and dis-engagement of the contacts comprising a driven member connected to the drum and spring means biasing said member to a contact opening position, means for operating the driven member comprising a snap action mechanism disposed in the housing at one end of said fixed contact carrying blocks, a driving member carried thereby juxtaposed to said driven member and means interposed between said driving and driven member to connect said members to each other, spring means to maintain said connection and thermally responsive means to break said connection, said biasing means adapted to open said contacts when the thermally responsive means operates, and manually operated means disposed for engagement with said connecting means for the driving and driven members movable to cause said means to be effective when the thermally responsive means has acted. MAX LEROY JEFFREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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