US2604792A - Snap action mechanism - Google Patents

Description

July 29, 1952 M. L.. JEFFREY SNAP ACTION MECHANISM Original Filed April 19, 1947 3 Sheets-Sheet 1 July 29, 1952 M. l.. JEFFREY SNAP ACTION MECHANISM original Filed April 19. 1947 3 Sheets-Sheet 2 July 29, 1952 M. L.. JEFFREY SNAP ACTION MECHANISM Original Filed April .7.9. 1947 3 sheets-sheet s Patented July 29, 1952 SNAP ACTION MECHANISM Max L. Jeffrey, Shaker Heights, 0hio original application April 1e, 1947, serial No. 742,578, now Patent No. 2,588,632 dated March Divided and this application December 15, 1948, Serial No. 65,350

5 Claims.

This invention relates to improvements in switches and switch operating mechanisms and more particularly to quick acting switches of the snap action type. This is a division of my co pending application, Serial No. 742,578, filed April 19, 1947, now Patent No. 2,588,632.

Although snap action switches have been proposed before and are well known in the art, the snap action, if suilcientlyl rugged to vwithstand heavy duty, wascumbersome, complicated and expensive to manufacture. a'

By the present invention, I have provided an improved snap action switch which is very compact, simple and positive in operation, inexpensive to manufacture and is suitable for the most heavy duty in which such switches may be utilized.

The snap action is also` particularly useful in conjunction with a` multiple contact circuit breaker andas such will vbe described in conjunction therewith. AvIt will-ber appreciated that it is useful for communicating a snap action to other 'types of circuit breakers, however, and therefore is/not limitedin its use to the par- .ticular type shown and described.

In a multiple circuit, it is essential in many instances that the'switch be designed to provide some circuits which are closed while other circuits are open. This makes it necessary, in each such circuit,v to design or obtain a switch adapted for that particular use. Eventually, in the case rof complicated ormultiple circuits, it becomes necessary to design special switches for those. circuits which are not ordinarily useful excepty for that particular job. This increases the expense as well as delays the entire installation while the switch is being processed.

By my Present invention I` have provided a switch where the components are such that they may be added to orr subtracted from the assembly to provide a switch for as many circuits as is desired. Furthermore, the components are such that by the. mere reversal of certain components thereof, a switch is provided which opens or closes a circuit. Thus, a switch is provided which may open or close simultaneously any desired number of circuits without the necessity of special design.

Another advantage of the construction is that, should. the load through one section of the switch be more than through another section causing the contacts in the heavy load section to wear, a new section can be substituted quickly and easily, and it is not'necessary to` otherwise renew the entire switch. Furthermore, one section which wears, due to arcing, more than the other, may have the points dressed down and substituted for another sectomkwhere the wear has not been so large because of the reduced load. Thus, as time goes on, the sectionsV may be rotated until eventually they are all worn out simultaneously.

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

In the drawings:

Fig. 1 is a full size plan view oi a switch enrbodying my invention;

Fig. 2 is a frontend elevational view thereof;

Fig. -3 is a section taken on the line 3-3 of Fig. 1;

Fig. fi is a rear elevational view thereof;

Fig. 5 is a vertical medialv section through the switch;

Fig. 6 is a side elevational view of one of the levers which go to make up the snap action mechanism; p

Figs. '7 and 8 are sections taken on the lines Figs. 9 and 10 are front and side elevational views respectively on another lever which coopcrates with the lever shown in Fig. 6 in making up the snap action mechanism;

Figs. 11 and 12 are side and end elevational views oi the support kfor the levers. of Figs. 7 and 9;

Figs. 13 and 14 are side and elevational views respectively of a connector coupling for connecting the snap action mechanism and the switch assembly;

Figs. 15 and 16 are iront and side elevational views of a switch rotor;

Fig. 17 is a plan view of a contact carrying strip and its contacts;

Fig. 18 is an edge view thereof with part broken away and shown in section;

Fig. 19 is an end elevation of the switch with one of the front plates removed to show the snap action mechanism;

Fig. 20 is a plan View of a switch Showing an alternate form of assembly and with certain parts broken away to show'a plan view of the snap mechanism;

Fig. 21 is a section taken on the line 2l -21 of Fig. 20, with certain of the parts shown in side elevation; and

Fig. 22 is a of Fig. 20.

The mechanism about to be described is illustrated as being without a housing. 'It will be appreciated., however, that a housing is contemplated, although there may be cases, where the switch is used in. conjunction with other apsection taken on the lines 21'2--22 paratus, where the housing for such apparatus will also house the assembly.

Likewise the switch is operated by a rocking or rotating shaft but no particular means is shown connected to the shaft for effecting such rocking or rotation, since this can be effected in many ways as by an electrically operated solenoid, hydraulically or mechanically,

Briefly, the embodiment of my invention shown contemplates a snap action mechanism'whereby a turning movement of a shaft causes a certain amount of kinetic energy to be built up in the mechanism which is released at a predetermined time to cause the quick snap rotary action which is communicated to the movable contacts through a coupling.

The circuit breaker. portion of the switch includes pairs of fixed contacts and movable contacts which are moved into and out of engagement therewith. Each set of contacts, for oontrolling a single circuit is housed in a separate housing, and by merely turning one of the housings end for end, thatA circuit can be normally open or closed. There isno limitation on the number of housings and their elements that can be used. Therefore, a switch can be fabricated for any particular job with the same parts, all as will heretofore more clearly appear.

As can best be seen in Figs. 1 to 3 inclusive, the snap action mechanism includes a rectangular base plate I having a pair of outwardly extending bosses II at its upper end. A pair of bosses I2 are also provided spaced from the bottom edge of the plate and the upper bosses. Intermediate the two upper bosses I I is a circular boss I3'. The bosses I2 are provided with outwardly extending pins I4 for engagement in apertures in a front plate I6, and they are also provided with threaded apertures, which together with the threaded aperture in the boss I3 are adapted to receive screws I5 which hold a front plate I6 in position. The pins I4 enter into holes in the plate and properly locate the'same, and the front plate is thus held in spaced parallel relation to the back plate. The front plate is of generally rectangular form being provided with an upwardly extending portion I8 which extends between the bosses I I.

The base plate is provided with an opening 20 in its mid-section, the opening being reinforced by an annular boss 2I on the rear thereof which extends around the opening, the opening through the plate and the boss constituting a bearing for the coupling shown in Figs. 13 and le.

The coupling comprises a barrel 23 rotatably journalled in the opening 20 and is provided with a projection 24 which extends rearward of the plate and is vertically slotted at 25. The slot provides means for connection with the switch rotors or tumblers later described.

The coupling is provided with a flange 2S adapted for engagement with the front of the base plate I0 and a circular projection 21 which provides a bearing surface for the lever illustrated in Fig. 7. The barrel of the switch is provided with an axial bore 28 to provide a bearing for the operating member (Fig. 11) and is slotted horizontally at 29.

The operating member includes a pivot pin 30, adapted to be rotatably journalled in the bore 2S of the coupling, and a cylindrical body 3| rotatably journalled in an opening in the front plate. A flange 32 is provided, which engages with the back of the front plate and is held thereby in position. The body 3I is provided with longitudinally extending slots 33 which extend the length of the body on opposite sides at its diameter and also across the end which projects beyond the front plate, adapted to have an operating member, not shown, secured thereto.

Movement from the operating member is transmitted to the connecting member by a snap mechanism supported in part by the two members and in part by the front and back plate. This mechanism includes the two levers of Figs. 6 to 8 inclusive and Figs. 9 and 1I). The lever of Fig. 9 is provided with a ring shaped body 40 having inwardly. extending tongues 4I adapted to engage in the side slots 33 of the operating member.

Extending upwardly from the body is a neck 42 which carries on its end a head 43 having two slanting cam faces 44. This lever is adapted to be swung together with the operating member, the ring 40 being disposed on the body of the operating member, with the tongues 4I extending into the slots 33. p

The second lever, as best shown in Figs. 6 to 8 inclusive includes twov spaced apart members adapted to be disposed on opposite sides of the nrst lever. The one part includes a ring shaped body 50 which is rotatably journalled on the body 3l of the operating member adjacent the rear of the ange 32. It likewisehas a neck 52 extending upward and which carries a head 53 on its end. The other part of the member is of the same conformation, except that the ring 50 is provided with inwardly extending tongues 54 and is adapted to be disposed over the part 21 of the connector member with the tongues 54 engaged in the slot 29. The two portions of the second lever are held together in spaced relation by pins 55 the ends 5'I of which are oi reduced cross section and extend through openings'in the heads 53 and are headed over to hold the same in place.

The head 53 is of generally T-shape, the extremities extending downward. The mid portion 59 is arcuate and is provided with two steps or notches 60 equally spaced from the center and spaced from the end, for engagement with pawls as will later appear.

It will thus be seen that the first lever 40-44 is xed on the operating member 30-33 and the second lever 50-60 straddles the nrst lever, rotates freely on operating member but has a driving connection with the connector 23-29.

Spring means is provided for transmitting movement from the first lever to the second lever and hence from the operating member to the coupling member and comprises a C-shaped spring 62 of appreciable width, the ends of which engage with all of the necks 42 and 52 of the two levers. It will thus be seen that the movement from one lever to the other is transmitted throngh the spring and that should either one of the levers meet with any resistance which would tend to hinder its movement the other lever can continue to move, the ends of the spring merely being pushed apart.

It is by virtue of this action that the snap action is obtained. This is eiected by holding the second lever against movement until a predetermined relative movement between the two levers is obtained and a predetermined amount of spring pressure is built up at which time the lever is released, and the spring, the ends of which are pressed against the misaligned necks, snaps the two levers into alignment.

The bosses II are provided with downwardly extending portions 65 in which are disposed pins Eextending outward from the plate and-.on which are iournalled paw-ls 6T which include a body of generally rectangular form, the ends of which are biiurcated at G3 to provide a yoke in which a roller GSi/is disposed on a pin '.'ilA extending through the arms of the yoke.

The roller SSextends between the spaced' apart headv portions 53 of the lever`560 while the body of the pawlli'fis of sufficient width'to bridge these portions. Helical springs 'H are" provided rfor urging the pawls toward the surfaces ligand notches t6, having one end' seated in a recess T2 in the pawl andthe other end in engagement with the slanting surface T3 on the boss 65.

In operation the two levers are normally held in alignment by the spring 62 which, asr stated, engages with the necks. The lever 40.--44 isswung when the coupling Sal-33 is rotated but' the lever Ele-53 is held against movement by one of the pawls Si?, the end of which engages in one of the notches Gill on the periphery ofV tllelTv shaped head. The result is that although the center lever is moved, the outside lever 'stands still and thenecks on the two levers which are then swung out of alignment force the ends of the spring 62 apart. The further out of alignment the tw-olevers move, the greater the tension built up in the spring.

:is the lever iB-lf3 is swung farther, one of the cam races 44 eventually engages the roller ES. on the pawl forcing the pawl upward vagainst the pressure of the spring 'l I. The pawl is thus eventually forced out of engagement with the notch tu and releases the outside' lever 5ll-53. At this time the spring which has had the ends pushed apart and is exerting considerable pressure against the misaligned necks of the two levers, snaps the two levers quickly into alignment. The outside lever then swings to the opposite position to that shown in -Fig. 2 and the other pawl is engaged in the other notch 66.

The spring 52 can be a single C shaped spring, or it can consist oi several springs placed on top of each other. Springs may beadded or removed or stiffer springs may be substituted to provide substantially any tension desired.

The tongues 54 on the outside lever being engaged in the notches 29 'of the coupling 23-28 which is j ournalled in the base plate, the coupling is quickly rotated, which movement is communicated to the switch rotor or rotors.

As previously1 stated, the snap' action mechanisw is adapted" to move the switch rotors to r y open or close the contacts. vPreferably, ea i rotor is disposed in a separate housing, and :le housings be secured together with the rotor one housing in interlocking engagement with the other to thus enable all of the rotors to be operated in unison.

Each of the housings may be comprised of a suitable insulating material, preferably such as be readily molded and is not subject to distortion or deformation in the presence of heat.

is best shown in 3 and 4, each housing has a body or sidewall 'i5 in which a recess 'I6 is formed, the recess being of suitable conformation to house the rotor Tl which is capable of limited movement therein. rl'he one end of the recess is closed by a wall 18 which is apertured at 'i9 to provide a bearing ksurface for the hub 8B of the rotor.

The terminal strips 8| are provided having one end disposed in recesses El opening to the exterior of the housing, and extending through the wall to the interior as indicated at B2. The interiorly extending part of the strip is backedby a boss 83 on the housing, andcarries a fixed contact 84, the strip being so arranged that the contact is in thepath of travel of 'the movable contact carriedby the rotor. If desired, the terminal strips 8| may bev secured in the housing during the molding operation.

The end of the strip in the recess may beprovided with one or. moreterminal screws 85. The base plate l0 isA provided with rearwardly extending bosses 8l, one of which is oppositer to the post I3, and the. othertwo. are disposed at the n lower end of the plate adjacentoppositecorners. rI he bosses are provided with threaded openings for the reception of' screws 88. which extend through ber tubes` I3J0V disposed in openings 89 in the housings. Thus a series of housings may be secured to the base plate 1.9.

The rotors which carry the movable contacts each comprise a hub 800i cylindrical form, which, as stated, is journalled in the wall of the housing and is provided with a tongue 90 on one end adapted to extend into and engagev the walls of the slot of the` couplings 2'3-29 to provide an operating connection therebetween. or, as will later appear, the tongue may engage in the slot of another rotor.

It should be noted, as can best be seen in Fig. 5, that the bearing surface doesnoti extend entirely through the wall butterminates substantially half way through the wall.v

The other end of the hub extends outward and A housings` cooperatesv with the other housing and that one housing acts as a. closing wall for the other housing. It: will al'soappearthat in a oase where all the housings face in the same direction, the last housing would be` open and its rotor unsupported if it were not for the fact that the housing can also be closed by a single plate which has an opening 96 in which the huby of the rotor is journalled. This is shown clearly in Fig. 5 where the plate S5 is utilized to provide a wall between the second and third sections, or in Figs. 20 and 21 where the plates are used to separate the housings.

At this point it should. be noted that in some instances it may befd'esirable to make each of the housings in two parts, in which event the wall portion T8' of the housingl would be open on both sides and only comprise the parts extending from the wall. This is shown clearly in Figs. 20 and 21.

.Each rotor is also provided with a pair of curved arms 98' which extend outwardly from diametrically opposite sides of the hub and are provided with flat faces 99, Figs. l5 and l5 having circular bosses IUD which extend inopposite directions and toward a horizontal line through the diameter oi the hub but spaced therefrom. The hub is formed with a slot |.0'2 which extends transversely of the hub along they horizontal diameter thereof and the walls 83 which diverge slightly from the center of the hub toward the periphery.

A contact carrying strip is provided for the hub and includes a flat bar 105, adapted to rotate freely in the slot I2 and capable of relative movement between the walls thereof. The mid section of the bar is provided with a tongue H35 adapted to extend into and having a bearing in a circular recess Ill?! in the axis of the rotor hub and opening in the bottom of the slot i D2.

The ends of the contact strip are enlarged at |08 and have secured therein in any suitable manner, as by riveting, the contacts |09, Figs. 17 and 18. Preferably, the Shanks of the contacts extend through the portions |08 and are headed over at to provide a boss for retaining a helical spring in place, the other end of the spring being disposed on the boss |00. Thus, the springs tend to hold the contact strip rotated in a counter clockwise position as shown in Fig. 3 with the sides of the strip in engagement with the walls |03 on opposite sides of the axis of the rotor.

When the contacts are closed, as shown in Fig. 4 upon the rotary contact meeting the xed contact, further rotary movement of the contact strip is prevented, but the rotor may continue its rotation relative to the strip which pivots about the tongue |06, the springs |I compressing and the sides of the strips moving away from the walls |03. Thus, in the contact closed position the contacts are held in spring pressed engagement with the fixed contacts.

It will be noted from Figs. 1 and 3 that the snap action mechanism is in its left hand position, and that to operate it the operating member 53E-33 must be moved in a clockwise direction. This movement is communicated to the rotor which is also moved clockwise as viewed from the right and of Fig. 1 or counter clockwise as viewed in Fig. 3 to cause the closing of the contacts.

This is true of the rst and second sections of the switch as viewed in Fig. l, but it will also be noted that the third and fourth sections are turned around; that is, turned end for end so that they face in the opposite directions to those of sections one and two. In this case, the plate 95 is disposed between the two sections, and as can be seen in Fig. 5, since the hubs of the rotors, which have slots |20, which align with the tongues 9|) on the opposite end and are normally disposed for engagement with the tongues on the adjacent rotor (Fig. 5) are toward each other, a coupling member |2| in the form of a fiat rectangular bar, which may also be insulating material, is disposed in both slots |20 of the adjacent rotors connecting them together.

The remaining or end section is also turned around. Therefore, the tongue and groove connection therebetween is provided.

It will be seen therefore that sections one and two have the contacts open, and that sections three and four (Fig. 4) have the contacts closed. Therefore, when the snap action mechanism is operated, the open contacts close, and the closed contacts open.

It will be appreciated that by this arrangement any number of sections can be built up to provide a single contact for the desired circuit, and wherein simultaneous opening and closing of circuits is attained.

I have described the sections as being held together with a screw 88 which extends through aligned openings in the discrete sections. There is also shown a fiber tube |30 which is first inserted in the openings and subsequently the screw extends through the tube. This construction increases the dielectric path and prevents arcing to the bolt.

In Figs. 20 and 21 I have shown a three-section switch wherein the side wall sections are separated from the end walls.

In this case the contact carrying strips 8| are somewhat narrower than in the other design and are secured in place during the molding. In all other respects, however, it is the same as that of Figs. 1 to 5 inclusive.

As can best be seen in Fig. 19, the ends of the lever 50--60, at the limit of their movement are closely spaced to the top surface of the lower bosses |2.

This spacing is maintained by the springs on the contacts which in the closed position are under compression. The end of the lever may contact with the bosses |2 limiting the movement and removing strain from the rotors in event that the operating member has a tendency to over travel, causing a further relative movement of the snap action levers. It will be apparent that considerable over travel is allowable because of this construction without undesirably affecting the operation.

It will therefore be clear that the snap action is small, rugged, simple and economical to manufacture, and that it takes up a minimum of space allowing a compact assembly to be made. It is also apparent how the switch assembly per se is versatile, enabling a few standard parts to be used and allow the fabrication of a switch which can control a great variety of circuits.

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 my invention.

I claim:

1. A snap mechanism comprising first and second coaxially aligned rotatable shaft sections movable relative to each other, a driver member carried by the first section and a driven member carried by the second section and spring means connecting the driving and driven members, means for holding the driven member against movement including pawls for engagement with the driven member, said driven member being formed with a slot extending longitudinally thereof and a curved surface concentric to the shaft axis having spaced apart notches for alternate engagement with said pawls, said pawls having portions resting on said curved surface and other portions extending alongside said driven member into said slot and in the path of travel of the driver member, said driver member being arranged to engage said last mentioned parts of the pawls and raise them alternately in said slots to disengage said pawls from said notches.

2. A snap action mechanism including a driven member and a driving member, means to connect said members whereby a slow rotary movement is converted to a fast rotary movement including a driven lever connected to said driven member and comprising a pair of spaced apart members rigidly connected to each other, a driving lever connected to said driving member and disposed between the spaced members of the driven member, spring means for holding said driving and driven members in predetermined position relative to each other adapted to have its tension increased upon relative movement between the levers, said driven member having a portion formed with spaced apart seats, separate pawl means disposed for engagement with said seats, and means carried by each pawl extending between the spaced apart elements, and means on said driving lever for alternate engagement with the means carried by each pawl to move said pawl out of engagement with said seat upon a predetermined movement of the driving member, said spring adapted to move the driven member upon relays of the pawl.

3. An apparatus of the class described including an operating member comprising a slotted barrel, a reduced extension on said barrel, a driving lever having a ring disposed on the barrel and provided with tongues extending from the inside of the ring into the slots, a neck extending from the ring and a head on the end of the neck formed with cam faces on the end of the head, an operated member journalled on the reduced extension at one end and supported in a bearing on the other end, a driven lever having a ring portion rotatably journalled on said barrel and disposed on one side of the driving lever and a second ring portion disposed beyond the end of the slotted barrel and the other side of the driven lever, tongues extending inwardly from the ring in the second portion and engaging in grooves of said operated member, said driven lever having necks extending therefrom in spaced axial relation to each other on opposite sides of the neck on the first lever, cam members carried by said necks on the ends thereof and swingable on opposite sides of the driving lever, means rigidly connecting said cam members together at their ends, spring means for drivingly connecting said levers together disposed around said rings and engaging said necks on opposite sides, latch means for said second lever, said cam members on the driven lever having a curved intermediate portion and formed with latch engaging shoulders at the end of the intermediate portion, said latches being pivotally journalled and swingable into and out of engagement with said shoulders, and means on said latch comprising a roller extending between said cam members adapted for engagement by said cam faces on the head of the driving lever, spring means for holding said latches against said cam faces and for urging said latches alternately into said notches, said rst cam upon being swung being alternately engageable with the rollers on said latches and said driven lever being movable by said spring upon release of one latch and engageable upon said movement by the second latch to hold the same in alternate locked positions.

4. An apparatus of the class described including an operating member comprising a slotted barrel, a reduced extension on said barrel, a driving lever having a ring disposed on the barrel and provided with tongues extending from the inside of the ring into the slots, a neck extending from the ring and a head on the end of the neck formed with cam faces on the end of the head, an operated member journalled on the reduced extension at one end and supported in a bearing on the other end, a driven lever having a ring portion rotatably journalled on said barrel and disposed on one side of the driving lever and a second ring portion disposed beyond the end of the slotted barrel and the other side of the driven lever, tongues extending inwardly from the ring in the second portion and engaging in grooves of said operated member, said driven lever having necks extending therefrom in spaced axial relation to each other on opposite sides of the neck on the rst lever, cam members carried by said necks on the ends thereof and swingable on opposite sides of the driving lever, means rigidly connecting said cam members together at their ends, spring means for drivingly connecting said levers together disposed around said rings and engaging said necks on opposite sides, latch means for said second lever, said cam members on the driven lever having a curved interme- 10 diate portion and formed with latch engaging shoulders at the end of the intermediate portion, said latches being pivotally journalled and swingable into and out of engagement with said shoulders, and means on said latch comprising a roller extending between said cam members 'adapted for engagement by said cam faces on the head of the driving lever, spring means for holding said latches against said cam faces and for urging said latches alternately,7 into said notches, said rst cam upon being swung being alternately engageable with the rollers on said latches and said driven lever being movable by said spring upon release of one latch and engageable upon said movement by the second latch to hold the same in alternate locked positions, abutments disposed for engagement with the ends of the driven member for limiting the movement thereof.

5. A snap action mechanism comprising rst and second rotary members in axial alignment, driving members connected to one of said rotary members and a driven member connected to the other, said driven member comprising a pair of rigidly connected spaced apart portions one of which is rotatably journalled on the first rotary member and the other of which is rigidly connected to one other member, said driving member being drivingly connected to said first rotary member and disposed between the spaced apart portions of the driven member, said members being provided with radially extending portions the lateral edges of which coincide, spring means engaging with said lateral edgesunder tension for holding said radially extending portions in alignment with each other adapted to increase in tension upon relative movement of said members, said driven members extending beyond the end of the driving member and provided with the ends extending laterally from said radially extending portions in the directions of travel of said member, said laterally extending portions being provided with spaced apart notches, separate pawl means each disposed for alternate engagement in said spaced apart notches upon said driven member being moved to predetermined position, rollers carried by said pawls and extending between said spaced apart portions, said driving lever having a portion movable into alternate engagement with each of said rollers to force said pawls out of said notches.

MAX L. JEFFREY.

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

UNITED STATES PATENTS Number Name Date Re. 17,304 Knaak May 7, 1929 665,514 Ely Jan. 8, 1901 1,945,819 Millermaster Feb. 6, 1934 1,979,277 McLoughlin Nov. 6, 1934 2,262,306 Thompson Nov. 11, 1941 2,270,951 Jeffrey Jan. 27, 1942 2,319,503 Glogau May 18, 1943 2,352,815 Van Valkenberg July 4, 1944 2,395,572 Meurer Feb. 26, 1946 2,453,161 Schleicher Nov. 9, 1948 2,468,551 Goff Apr. 26, 1949 FOREIGN PATENTS Number Country Date 498,439 Germany May 24, 1930

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