US2558258A

US2558258A - Snap acting device

Info

Publication number: US2558258A
Application number: US207035A
Authority: US
Inventors: Everard F Kohl
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-03-14
Filing date: 1951-01-20
Publication date: 1951-06-26
Anticipated expiration: 1968-06-26

Description

June 26, 1951 Original Filed larch 14, 1941 E. F. KOHL sun ACTING DEVICE 2 Sheets-Sheet 1 Everard F Koh l ATTORNEY E. F. KOHL SNAP ACTING DEVICE June 2 1951 2 Shet s-Sheet 2 Original Filed March 14, 1941- INVENTOR' Everard F Kohl 5% WW ATTORNEY Patented June 26, 1951 UNITED STA ES PATENT OFFICE 383,436. Divided and this 20, 1951, Serial No. 207,035

18 Claims.

1 My invention relates to a snap acting device and more particularly to an electric switch and is a division of application Ser. No. 383,436 filed on March 14, 1941, which in turn is a continuation in part of application Ser. No. 214,923, filed on June 21, 1938, which has matured into Patent No. 2,237,705.

One of the objects of the present invention is to provide an improved electrical switch in which a force is applied to the free end of an actuating member to move a contact carrier in the opposite direction with a snap motion to cause engagement of a movable contact with a stationary contact.

Another object of my invention is to provide an improved snap acting device in which means are provided for applying a force to the free end portion of an actuating means to move an arm to be actuated in the opposite direction with a snap motion and in which the actuating means automatically returns to its original position when the force is released.

A further object of my invention is to provide an improved snap acting device in which the free end portion of an actuating member is biased from the free end portion of an arm so that it will automatically return to its original position when the force upon the actuating member is released.

A still further object of my invention is to provide an improved snap acting device in which the fixed end of an actuating member is spaced a suflicient distance from the fixed end of a member to be actuated so that when a force is applied to the actuating means to cause actuation of the switch, it will return to its original position when the force upon the actuating means is released.

My invention will be better understood by reference to the accompanying drawings in which:

Fig. l is a side elevational view of one form of my improved switch; I

Fig. 2 is a similar view of the switch shown in Fig. l with the parts in a dififerent position;

Fig. 3 is a front elevational view of the switch shown in Figs. 1 and 2 with the parts in the position shown in Fig. 1

Figs. 4 and 5 are side elevational views of modifications of my improved switch;

Fig. 6 is an enlarged detail view of a portion of the switch shown in Fig. l

Fig. 7 is a view similar to Fig. 6 when the actuating member is moved to a critical position;

Fig. 8 is a view similar to that shown in Figs. G and 7 when the parts are in the position shown in Fig. 2;

application January Fig. 9 is a side elevational view of another modification of my improved switch with parts shown in section;

Fig. 10 is an enlarged cross sectional view of a portion of the switch shown in Fig. 9 with parts shown in elevation; and

Fig. 11 is a lower plan view of a portion of the switch shown in Fig. 9 taken on the line ll--ll of Fig. 9, looking in the direction of the arrows.

In the accompany drawings, snap acting devices are disclosed in which actuating means and an arm to be actuated each have a free end portion provided with an abutment upon which abutments a spring rolls or rocks during movement of the actuating means relative to the arm and in which an actuator is or may be applied to the actuating means to move the arm in the opposite direction to force a movable contact into engagement with a stationary contact.

One form of my invention is illustrated in Figs. 1 to 3, inclusive, in which an electrical switch is shown comprising an arm I to be actuated having a free end portion provided with an abutment or shoulders 2 and 2a, an actuating member or lever 3 having an opening or cut-out therein and being provided with an abutment or

shoulders

4 and 4a bordering the end of the opening which abutments are arranged in proximity to but spaced from the free end portion of the actuating member or lever 3, and spring means 5 having one portion rockably mounted on the abutments or shoulders on the arm and another portion rockably mounted on the abutments or shoulders upon the lever when the actuating member is moved relative to the arm.

While thearm I to be actuated and the actuating lever 3 may be formed integrally and supported in any desired manner, as shown in Figs. 1 to 3 of the drawings, both members are formed of flexible resilient metal and the stationary end of the actuating lever 3 is arranged adjacent to and is secured to the stationary end of arm I intermediate a pair of spaced arms 6 and I in any convenient manner, such as by a suitable base structure designated generally by the numeral 8, and arm I which is formed of a suitable electrically conductive metal, such as copper or brass,

electrically conductive metal, or if a single throw switch is desired, either the arm 6 or arm 'I may be utilized as a stop. As shown, arms 6 and I are sufliciently rigid to maintain contacts I and I2 in a stationary position.

While the base structure 8 may be of any suitable form for securing the fixed ends of arms 6 and I and the fixed ends of arm I and lever 3 in place and maintaining arms 6 and I in spaced electrically insulated relationship, as shown the parts are held together by means of bolts I3 which pass through apertures in the adjacent ends of the arms and lever and through insulating material which is interposed in the form of strips I4 between the heads of bolts I3 and arm I, between arms 6 and "I, respectively, and arm I and lever 3, and between arm 6 and nuts 15 by means of which the bolts are held in place. The metallic members are also insulated from the bolts by any suitable means, such as tubes I6. To provide terminals I'I, I8 and I 9, a portion of arm 6, lever 3, and arm I extend beyond the base structure. While in thestructure shown, lever 3 is extended to form terminal I8 because it is formed of thicker metal than arm I and the adjacent ends of arm I and lever 3 are held together by the bolts in electrical contact with each other, if desired, terminal I8 may be formed upon arm I.

In my improved switch, the parts are so arranged that only a comparatively small force is required to actuate the switch. For this purpose, the actuating lever is longer than the arm to be actuated and is provided adjacent its free end with a handle or actuator 20 and the spring means rocks or rolls upon the abutments 2 and 2a on the free end of arm I and the

abutments

4 and 4a bordering the outer edge of the opening 3a on lever 3, and while the spring means may be of any desirable shape to efiect this purpose, as shown in the drawings, an arcuate-shaped spring 5 is provided which is maintained in operative association with arm I and lever 3 in any suitable manner. For instance, the arm I and lever 3 may each be provided with spaced projections or tongues extending from their respective abutments and one end of the spring may be provided with notches in its opposite edges of sufificient width to loosely receive the tongues or projections on the arm and its opposite end may be provided with notches in its opposite edges of sufiicient width to loosely receive tongues or projections on the actuating member as more particularly disclosed in Figs. 9 to 12 of my copending application Ser. No.

383,436. As illustrated in the drawings, the arm I is provided with a tongue 2| projecting from abutments 2 and 2a which tongue extends loosely through an aperture 22 adjacent one end of spring 5 and lever 3 is provided with a tongue 23 projecting from

abutments

4 and 4a which extends loosely through an aperture 24 adjacent the opposite end of spring as clearly shown in Figs. 6, 7 and 8. While the spring 5 may be preformed, if desired, it preferably consists of a thin fiat strip of resilient metal of spring temper, such as steel, beryllium, copper, brass, bronze, or the like. which is cut to the desired length and is provided with apertures spaced a short distance from its opposite ends and loosely receives tongues 2| and 23 when the spring is compressed into substantially a semielliptical shape with one portion of the spring resting upon the abutments or shoulders 2 and 2a of arm I and another portion resting upon the abutments or

shoulders

4 and 4a of actuating member or lever 3. Springs of the same length and sensitivity may therefore be readily prepared in a commercial manner so that switches in which they are utilized may be duplicated without providing an adjustment for variation in the spring.

When a spring having an arcuate-shaped portion as shown in Figs. 1 to 5, 6, 7 and 8 is assembledin place between abutments or shoulders 2 and 2a on the arm and abutments or

shoulders

4 and 40. on the actuating member, the shoulders or abutments maintain the spring under compression and the spring in turn exerts a force as designated by the arrow A which maintains the free end portion of the actuating member or' lever in spaced relation to the free end of the arm and exerts a force to stress the free end of arm I to maintain the movable contact 9 in firm engagement with the stationary contact I0 and if desired, spring 5 may be formed of stronger material than arm I to accentuate this action. When the parts are in the position shown in Fig. i, it will be noted, see Fig. 6, that one portion of the spring engages the inner edges 25 of abutments or shoulders 4 and 411 on the actuating lever and another portion of the spring engages the inner edges 26 of abutments or shoulders 2 and 2a on the arm I and that the actuator 20 is secured to the free end of the actuating lever 3 by suitable means, such as rivets 21 and is provided with an opening 28 to receive any suitable means for applying force to the actuator 20.

To actuate the switch, a force is applied to the free end of the actuator 20 to cause the inner edges of

abutments

4 and 4a or the inner edges of tongue 23 adjacent the

abutments

4 and 4a to engage spring 5 and rock it upon the abutments 2 and 2a upon arm I and upon

abutments

4 and 4a on the actuating lever 3 to gradually change the direction of its force during movement of the actuating lever 3 to a critical position in which the free end of tongue 23 and

abutments

4 and 4a are substantially in alignment with the free end of tongue 2| and abutments 2 and 2a as illustrated in Fig. '7. During movement of the actuating lever to its critical position, it will be noted that while a portion of the spring rolls or rocks upon abutments 2 and 2a, movable contact 9 remains in engagement with stationary contact Ill and is held in engagement therewith by the force of spring 5. Upon movement of actuating lever beyond its critical position, however, a. further rolling or rocking movement of the spring takes place, causing a third portion of the spring to engage the outer edges 29 of the

abutments

4 and 4a on the actuating lever and a fourth portion of the spring engages the outer edges 30 of abutments 2 and 241 on arm I and when spring 5 reaches this position, the direction of its force is changed to such an extent that it throws the actuating lever 3 forwardly in its direction of actuation and the arm I in the opposite direction with a snap motion, thereby causing a further rapid change in the direction of the force of spring 5 and moving contact II into engagement with stationary contact I2 as shown in Fig. 2 in which the force of spring 5 as designated by the arrow C maintains the free end of lever 3 in spaced relation to the free end of arm I and exerts a force on and stresses the free end of arm I which extends above the movable contact I2 to maintain movable contact II firmly in engagement with stationary contact I2. When the parts are in the position shown in Figs. 2 and 8, it will be noted that a portion of spring engages the edges 29 01

' abutments

4 and 4a of lever 3 and a second portion of the spring engages the edges 30 of abutments 2 and 2a of arm I and when the spring is in the position shown in Figs. 2 and 8,

edges

25 and 30 may be considered the inner edges.

To return the parts to the original position, a force is applied in the opposite direction to actuator 20 as indicated by the arrow D to provide a rocking or rolling movement of spring 5 upon the abutments 2 and 2a on arm I and upon

abutments

4 and 4a on lever 3 to gradually change the direction of the force of spring 5 and when the actuating lever is moved beyond its critical position in which tongue 23 and

abutments

4 and 4a on lever 3 are substantially in alignment with tongue 2I and abutments 2 and 2a on arm I, a third portion of spring 5 engages the outer edge 25 of actuating lever 3 and throws the actuating lever forwardly in the direction of its actuation and a fourth portion of spring 5 engages the outer edge 26 of the abutments 2 and 2a on arm I and throws it in a direction opposite to the movement of the actuating lever to thereby cause a rapid change in the direction of the force of spring 5 and to disengage movable contact from stationary contact I2 and throw movable contact 9 into engagement with stationary contact III with a snap motion.

My improved snap acting device is particularly adapted to be utilized in electrical switches in which a momentary contact is established when force is applied to the actuating lever and in which the actuating member returns to its original position to disengage the movable contact from the stationary contact when the force upon the actuating lever is released as shown in Figs. 4 and 5.

The switch shown in Fig. 4 is similar to the switch shown in Figs. 1 to 3 with the exception that all portions of the actuating lever 3 are spaced to the right from arm I. The parts have accordingly been designated by the same reference numerals. 7

To actuate the switch, a force designated by the arrow E is applied to the flexible actuating lever 3 adjacent its free end against the force of spring 5, one portion of which spring engages the

inner edges'of abutments

4 and 4a on lever 3 anda second portion of which engages the inner edges of the abutments 2 and 2a on the arm I, and as lever 3 is moved in the direction indicated by the arrow E, spring 5 roll or rocks upon the abutments 2 and 2a on arm I and upon the

abutments

4 and 4a on lever 3 and when actuating lever is moved through a critioal'position in which tongue 23 and

abutments

4 and 4a on actuating lever 3 are substantially in alignment with tongue 2| and abutments 2 and 2a on arm I as shown in Fig. 7, a'third portion of spring 5 engages the outer edges of the abutments on actuating lever '3 to move it forwardly in the direction of actuation and a fourth portion of the spring engages the outer edges of the abutments on flexible arm I to throw arm 3 in a direction opposite to the movement of actuating lever 3. In the switch shown in Fig. 4, it will be noted that all portions of lever 3 are spaced to the right of arm I and spring 5 which is compressed between the abutments on the free end of arm I and the abutments at the outer edge of opening 3a in lever 3 exerts a force to flex the free end of lever 3 further to the right and to flex the free end of arm I to the left to maintain movable contact 9 in engagement with stationary contact II. When an actuator is applied to the free end of lever 3, asindicated by the arrow E to move lever 3 beyond its critical position, sufflcient energy will therefore be stored inlever 3 to cause it to return to its original position when the force upon the free end of actuating lever 3 is released and the return movement of the actuating lever will be accentuated by thei'orce of spring 5 after lever 3 passes its critical position. In the switch shown in Fig. 4, it will of course be understood that if only a momentary contact is desired, contact III may be utilized as a stop. In the switch shown in Fig. 4, arm I instead of lever 3 is extended beyond the base structureto form the intermediate terminal I8.

Instead of spacing all parts of actuating lever 3 from arm I as shown in Fig. 4, the flexible actuating lever 3 may be arranged adjacent to arm I and biased to the right as shown in Fig. 5, such as by. bending lever 3 to the right and form- 'ing a. permanent set therein. The modification shown in Fig. 5 is otherwise similar to the modification shown in Figs. 1 to 3 and the parts have accordingly been .designated by the same reference numerals. In Fig. 5, when spring 5 is compressed between

abutments

4 and 4a on lever 3 and abutments 2 and 2a on arm I, one portion of spring 5 engages the inner edges 25 of the abutments or shoulders on lever 3 and a second portion engages the inner edges 26 of the abutments or shoulders 2 and 2a on arm I and spring 5 not only flexes lever 3 further to the right but also stresses the free end of arm I to maintain stationary contact 9 in engagement with stationary contact In and when an actuator is applied to the free end of lever 3 as indicated by the arrow G to move actuating lever 3 to and beyond a critical position in which the

abutments

4 and 4a and tongues 23 on lever 3 are v substantially in alignment with abutments 2 and 2a and ton ue 2| on arm I, spring 5 is rocked upon the abutments to aposition in which a third portion of the spring engages the outer edges 29 of the

abutments

4 and 4a tothrow lever 3 forwardly in the direction of its actuation and a fourth portion of spring 5 engages the outer edges 30 of abutments 2 and 2a to throw arm I in the opposite direction with a snap motion to cause movable contact II to engage stationary contact I 2.

In moving actuating lever 3 to the left as shown in Fig. 5 to actuate the switch, energy is stored in the actuating lever to overcome thebias therein and when the force upon actuating lever 3 is released, the stored energy returns the actuating lever 3 to its original position rocking spring 5 upon the

abutments

4 and 4a; on lever 3 and the abutments 2 and 2a on arm I and when the lever passes through itscritical position, a third portion of spring 5 engages the edges 25 of

abutments

4 and 4a and a forth portion of the spring engages the edges'25 of abutments 2 and 2a to return the parts to their original position in which movable contact 9 is in engagement with stationary contact II). In the switch shown in Fig. 5, it will of course be understood that in'the event it is desired to establish and interrupt a ranged intermediate spaced

stationary arms

32 and 33 and is maintained at one end in fixed relation thereto by a suitable base structure designated generally by the numeral 34. Arm 3| which is formed of a suitable conductive metal, such a copper or brass, is provided with a contact 35 on one face that is spaced from its free end and which is movable into and from engagement with a stationary contact 39 carried on the inner face of the free end of arm 32. Arm 3| is also provided with a contact 31 on its opposite face that is spaced from its free end and which is movable into and from engagement with a stationary contact 33 arranged on the inner face of the free end of arm 33 although it will be understood that if it is desired to establish and interrupt a single circuit, one of the stationary contacts may be utilized as a stop. One end of a flexible resilient actuating lever or arm 39, which constitutes part of the actuating means, is also secured to one side of base structure 34 and one end of a rigid arm 43 for supporting an electromagnet 4| is secured to the opposite side of the base structure.

While the base structure 34 may be arranged in any suitable manner to support the fixed ends of arms 3|, 32, 33. lever 39. and arm 40, as shown electrical insulating material, such as molded or fibrous material, in the form of strips 42, is interposed between the fixed end of arm 3| and the fixed ends of

arms

32 and 33, respectively, between the fixed ends of arm 32 and lever 39, and between the fixed ends of

arms

33 and 43, and tubes 43 which are also formed of an electrical insulating material extend through openings in the fixed ends of arms 3|, 32, and 33 and abut against lever 39 and arm 49 to receive bolts 44, the heads of which bolts abut against lever 39 and are threaded in spaced openings in arm 49.

Because actuating lever 39, is spaced from arm 3|, it is not necessary in the structure shown in Figs. 9 to 11, inclusive, to provide an opening in the actuating lever. As shown, the free end of lever 39 serves as a support for a base 45 formed of a magnetizable material, such as iron or steel,

which has a stem 49 secured to the flexible lever.

39 by suitable means, such as a nut 41. The free end of lever 39 also supports an arm 43 which is insulated from base 45 by suitable means, such as a studded washer 49 formed of an electrical insulating material, and from stem 45 by a tube 53 formed of an electrical insulating material which is interposed between the lever 39, the stud of washer 43 and arm 48 and serves to maintain arm 43 in alignment with the fixed end of arm 3|. In the structure disclosed in Figs. 9 to 11, the actuating lever 33, the base 45 and its stem 45, and the arm 43, may be considered the actuating means.

As illustrated more particularly in Fig. 11 of the drawings, the free end of arm 3| and the free end of arm 48 are each provided with an abutment upon its free and upon which a spring is rockably mounted and spring 5| is held in engagement with the abutments by any suitable means, such as projections at the edge of each arm to loosely receive notches at the opposite edge of each end of spring 44, as disclosed in Figs. 9 to 13 Of my copending application Ser. No. 383,436 filed on March 14, 1941, or as illustrated in the drawings, arm 3| may be provided with a tongue 52 projecting from abutments or

shoulders

53 and 54 which tongue ex tends loosely through an aperture in spring 5| adjacent one end thereof and in a like manner arm 43 is provided with a tongue 55 extending from abutments or shoulders 55 and 5] which tongue extends loosely through an aperture in the spring 5| adjacent its other end in the manner illustrated in Figs. 6, 7 and 8 of the drawings. when the switch shown in Figs. 9 to ll, inclusive, is in the position shown in Fig. 9, a portion of spring 5| bears against the inner edges of shoulders or

abutments

53 and 54 upon the free end of arm 3| and a second portion of the spring bears against the inner edges of the abutments or

shoulders

56 and 51 on arm 43 and the force of the spring as designated by the arrow I flexes the free end of arm 3| which extends beyond contacts 35and 3'! and maintains movable contact 35 in firm seating engagement with stationary contact 31. When force is applied to the free end of actuating lever 39, however, to move arm 48 to a critical position in which arm 43 is substantially in alignment with the free end of arm 3|, spring 5| is rocked upon the abutments or shoulders on the free ends of arm 43 and arm 3| from the position as shown in Fig. 6 to the position as shown in Fig. 7 and when arm 43 is moved beyond its critical position, spring 5| engages the outer edges of the abutments on arm 48 and the outer edges of the abutments on arm 3| as shown in Fig. 8, forcing movable contact 35 into engagement with stationary contact 36 with a snap motion in which position the force of the spring 5| stresses the free end of flexible arm 3| and maintains movable contact 35 in firm engagement with stationary contact 35. While any type actuator may be utilized to move the actuating means to and beyond its critical position, as illustrated in Figs. 9 and 10, it is actuated by means Of the electromagnet 4| which is energized by means of a coil 53 connected to lead

lines

59 and 63 which are connected to any suitable source of electrical energy and which when energized draws plate 45 toward the magnet 4| moving lever 39 and arm 43 to and beyond their critical positions and places tension on arm 39 to store energy therein and during movement of the actuating means, spring 5| is rocked on the abutments on the free ends of arms 3| and 43 in the manner previously described. When the core 4| of the magnet is deenergized by interrupting the circuit to the coil, the energy stored in lever 39 during the actuation of the switch causes lever 39 to return to its original position and during the return of lever 39 to its original position, spring 5| rocks upon the abutments on arm 3| and arm 48 and when arm 43 passes. the critical position in which the tongue and abutments on arm 48 are substantially in alignment with the tongue and abutments on'arm 3|, spring 5| engages the outer edges of the abutments on arm 3| and the outer edges of the abutments on arm 43 to supplement the energy stored in lever 39 to return the lever 39 to its original position and to throw arm 3| in the opposite direction with a snap motion causing movable contact 31 to engage stationary contact 33. Terminals 3|, 52 and 53 upon the switch shown in Figs. 9 to 11 may be formed by extending

arms

32, 3| and 33 beyond base structure 34.

In the. switch illustrated in Figs. 9, l0 and 11, it will be particularly noted that because the actuator is applied to the actuating means to bend the free end of lever 39, the force required to actuate the switch will be comparatively small and because lever 39 is spaced throughout its length from arm 3|, the energy stored therein during actuation will cause it to return to its original position when the electromagnet is deenergized.

What I claim is:

1. A snap acting device comprising an arm to be actuated having a free end portion provided with an abutment, a flexible actuating lever having a free end portion which is biased away from said arm and the free endportion of said lever being provided with an abutment, and each of said abutments having spaced inner and outer' edges, spring means compressed between the abutment on said arm and the abutment on said lever and having one portion bearing against the inner edge of the abutment on said arm and another portion bearing against the inner edge of the abutment on said lever, means for maintaining said spring means in operative relation with said lever and said arm, and said lever being movable when force is applied thereto to rock said spring means upon said abutment beyond a critical position in which the abutment on said lever is substantially in alignment with the abutment on said arm and the movement of said lever beyond its critical position being efiective in rocking said spring means to a second position in which a third portion of said spring means engages the outer edge of the abutment on said lever and throws it forwardly in the direction of its actuation and a fourth portion of said spring means engages the outer edge of the abutment on said arm to throw said arm in a, direction opposite to the movement of said lever, and said lever being normally biased sufliciently away from said arm so that it will automatically return to its original position when the force upon the actuator is released.

2. A snap acting device comprising an arm to be actuated having a free end portion provided with an abutment, a flexible actuating lever of greater length than said arm and having a free end portion biased away from the free end portion of said arm and being provided with an elongated opening therein, one edge of which opening is spaced from the abutment on said arm and which forms an abutment on said lever, said lever being provided with a substantially fiat portion extending beyond its abutment to which an actuator may be applied and each of said abutments having spaced inner and outer edges, spring means interposed between the abutment on said arm and the abutment on said lever and having one portion bearing against the inner edge of the abutment on said arm and another portion bearing against the inner edge of the abutment on said lever, means for maintaining said spring means in operative association with said lever and said arm, and said lever bein movable when force is applied to its free end portion to rock said spring means upon said abutments to and beyond a critical position in which the abutment on said lever is substantially in alignment with the abutment on said arm and the movement of said lever beyond its critical position being efi'ective in rocking said spring means to a second position in which a third portion of said spring means engages the outer edge of the abutment on said lever to throw it forwardly in the direction of its actuation and a fourth portion of said spring means engages the outer edge of the abutment "released.

3. A snap acting device comprising an arm to be actuated having a free end portion provided with an abutment, a flexible actuatinglever having a free end portion biased away from the free end portion of said arm and being provided with an elongated opening therein, one edge of which opening is spaced from the abutment on said am and forms an abutment on said lever, said lever being provided with a. portion extending b y nd its abutment to which an actuator may be applied and each of said abutments having spaced inner and outer edges, an arcuate-shaped spring inter posed between the abutments on said arm and the abutment on said lever and having one portion bearing against the inner edge of the abutment on said lever and a second portion bearing against the inner edge of the abutment on said arm, means for maintaining said spring in operative association with said lever and said arm, and said lever being movable when force is applied to its free end portion to rock said spring upon said abutments to and beyond a critical position in which the abutment on said lever is substantialw in alignment with the abutment on said arm and the movement of said lever beyond a critical position being eii'ective in rocking said spring to a position in which a third portion of said spring engages the outer edge of the abutment on said lever and throws it forwardly in the direction of its actuation and a. fourth portion of said spring engages the outer edge of the abutment on said arm and throws said arm through the opening in said lever in a direction opposite to the movement of said lever and the free end of said lever being normally biased sufliciently from the free end of said arm so that it will automatically return to its original position when the force upon said actuator is released.

4. A snap acting switch comprising a stationary contact, a flexible arm to be actuated having a free end extending beyond said contact and being provided with an abutment adjacent its free end and a contact spaced from its free end which is movable into and from engagement with the stationary contact, an actuating lever having a fixed end and a free end portion extending beyond the free end portion of said am to which a force may be applied for actuating said lever and said lever being provided with an elongated opening therein, one edge of which opening is spaced from the abutment on said arm and forms an abutment on said lever and each of said abutments having spaced inner and outer edges, an arcuate-shaped spring compressed between the abutment on said arm and the abutment on said lever and having one portion bearing against the inner edge of the abutment on said lever and a second portion bearing against the inner edge of the abutment on said arm which spring has sufficient compressive force to maintain the movable contact in engagement with the stationary contact and to stress the free end portion of the arm extending beyond the movable contact, means for maintaining said spring in operative association with said lever and said arm, and said lever being movable when force is applied to its free end portion to rock said spring upon said abutments to and beyond a critical position in which the abutment on said lever is substantially in alignment with the abutment on said arm and the movement of said lever beyond a critical position being effective in rocking said spring to a position in which a third portion of said spring engages the outer edge of the abutment on said lever and throws it forwardly in the direction of its actuation and a fourth portion of said spring engages the outer edge of the abutment on said arm and throws said arm through the opening in said lever with a snap motion in a direction opposite to the movement of said lever and the free end portion of said lever being biased away from the free end of said arm to such an extent that it will automatically return to its original position when the force upon said actuator is released.

5. A snap acting device comprising an arm to be actuated having a fixed end and a free end portion provided with an abutment, resilient actuating means having a fixed end which is spaced from the fixed end of said arm and a free end portion provided with an abutment which is spaced from the abutment on said arm, spring means having one portion rockably mounted on the abutment on said actuating means and a second portion rockably mounted on the abutment on said arm, and means whereby a force may be applied to said actuating means to store energy therein and to rock said spring means upon said abutments to change the direction of the force of said spring means to a position in which it throws the arm in a direction opposite to the movement of the actuating means and the fixed end of said actuating means being spaced at a sufficient distance from the fixed end of said arm so that the energy stored in said actuating means during actuation is sufficient to cause said actuating means to return to its original position when the force upon the actuating means is released.

6. A snap acting device comprising an arm to be actuated having a fixed end and a free end portion provided with an abutment, resilient actuating means having a fixed end spaced from the fixed end of said arm and having a free end portion provided with an abutment which is spaced from the abutment on said arm and each of said abutments having spaced inner and outer edges, spring means compressed between said abutments and having one portion engaging the inner edge of the abutment on said actuating means and a second portion engaging the inner edge of the abutment on said arm, and means whereby force may be applied to said actuating means to store energy in said actuating means and to rock said spring means upon said abutments to and beyond a critical position in which the abtument on said actuating means is substantially in alignment with the abutment on said arm and the movement of said actuating means beyond its critical position being effective in rocking said spring means upon said abutments to a position in which a third portion of said spring means engages the outer edge of the abutment on the actuating means and throws it forwardly in the direction of its actuation and a fourth portion of said spring means engages the outer edge of the abutment on said arm and throws said arm in a direction opposite to the movement of said actuating means, and the fixed end of said actuating means being spaced at a suflicient distance from the fixed end of said arm so that sufficient energy will be stored in said. actuating means during the actuation of said switch to cause the actuating means to re- 12 turn to its original position when the force upon the actuating means is released.

7. A snap acting device comprising an arm to be actuated having a fixed end and a free end portion provided with an abutment, resilent actuating means having a fixed end spaced from the fixed end of said arm and being provided with a free end portion provided with an abutment which is spaced from the abutment on said arm and each of said abutments having spaced inner and oumr edges, an arcuate-shaped spring compressed between said abutments and having one portion engaging the inner edge of the abutment on said actuating means and a second portion engaging the inner edge of the abutment on said arm, said spring being rockable upon said abutments during movement of said actuating means relative to said arm, and means whereby force may be applied to said actuating means to store energy therein and to rock said spring upon said abutments to and beyond a critical position in which the abutment on said actuating means is substantially in alignment with the abutment on said arm and the movement of said actuating means beyond its critical position be ing eflfective in rocking said spring upon said abutments to a position in which a third portion of said spring engages the outer edge of the abutment on the actuating means and throws it forwardly in the direction of its actuation and a fourth portion of said spring engages the outer edge of the abutment on said arm and throws said arm in a direction opposite to the movement of said actuating means, and the fixed end of said actuating means being spaced at a suificient distance from the fixed end of said arm so that sufiicient energy will be stored in said actuating means during the actuation of said switch to cause the actuating means to return to its original position when the force upon the actuating means is released.

8. A snap acting device comprising an arm to be actuated having a fixed end and a free end portion provided with an abutment, resilient actuating means having a fixed end spaced from the fixed end of said arm and a free end portion arranged substantially opposite to and extending toward but spaced from the free end of said arm which free end portion of said actuating means is provided with an abutment, and each of said abutments being provided with inner and outer edges, spring means compressed between said abutments which spring means has one portion engaging the inner edge of the abutmerit on said arm and another portion engaging the inner edge of the abutment on said actuating means and said spring means being rockable on said abutments during movement of said actuating means relative to said arm, and an actuator for applying force to said actuating means to store energy therein and to rock said spring means upon said abutments to and beyond a critical position in which the abutment on said actuating means is substantially in alignment with the abutment on said arm and the movement of said actuating means beyond its critical position being effective in rocking said spring means upon said abutments to a position in which a third portion of said spring means engages the outer edge of the abutment on said arm and throws said arm in a direction opposite to the movement of said actuating means and the fixed end of said actuating means being spaced at a suflicient distance from the fixed end of said arm so that sufiicient energy will be stored in said actuating means during the actuation of said 13 switch to cause the actuating means to return to its original position when the force upon the actuating means is released.

9. A snap acting device comprising an arm to be actuated having a fixed end and a free end portion provided with an abutment having spaced inner and outer edges, resilient actuating means having a fixed end spaced from the fixed end of said arm, an intermediate portion extending toward the plane of said arm, and a free end portion extending toward the free end portion of said arm but spaced therefrom and the free end portion of said actuating means being provided with an abutment having spaced inner and outer edges, an arcuate-shaped spring compressed between said abutments and having one portion engaging the inner edge of the abutment on said arm and a second portion engaging the inner edge of the abutment on the free end portion of said actuating means and said spring being rockable upon said abutments during movement of said actuating means relative to said arm, means for maintaining said spring in operative association with said abutments, and an actuator for applying force to said actuating means to store energy therein and to rock said spring upon said abutments to a position in which a third portion of said spring engages the outer edge of the abutment on the free end portion of the actuating means to urge it forwardly in the direction of its actuation and a fourth portion of said spring engages the outer edge of the abutment on said arm and throws it in a direction opposite to the movement of the free end portion of said actuating means, and the fixed end portion of said actuating means being spaced at a sufiicient distance from the fixed end of said arm so that suflicient energy will be stored in the actuating means during actuation of said device to cause the actuating means to return to its original position when the force upon the actuating means is released.

10. A snap acting switch comprising a support, a pair of substantially rigid arms secured to said support and extending therefrom in spaced parallel relation to each other and at least one of said arms being provided on its inner face with a stationary contact. a flexible resilient arm arranged between the two rigid arms and having one end secured to said support and a free end extending beyond the rigid arms which free end is provided with an abutment, a contact carried by the flexible arm in spaced relation to its free end which contact is movable into and from engagement with the stationary contact, a flexible resilient actuating lever of greater length than said arm having one end fixed to said support between the rigid arms and having an elongated opening providing an abutment adjacent its free end which abutment is spaced from the abutment upon the free end of said arm, spring means interposed between said abutments and having sufiicient force when held under compression to maintain said lever in spaced relation to said arm and to maintain the movable contact in engagement with the stationary contact and to stress the free end portion of said arm to force the movable contact in firm seating engagement with the stationary contact, an actuator applied to the free end portion of said lever for moving said lever toward the free end portion of said arm. and said spring means being movable with the actuating lever during movement of said lever to rock said spring means upon at least one of said abutments during movement of said lever to and beyond a critical position to change the direction of the force of said spring means to a position in which it throws the arm to be actuated in the opposite direction with a snap motion to disengage the movable contact from the stationary contact and to force the flexible arm into engagement with the other rigid arm to limit the movement of the flexible arm.

.11. A snap acting switch comprising a support, a pair of substantially rigid arms secured to said support and extending therefrom in spaced parallel relation to each other, and each of said arms being provided on its inner face with a stationary contact, a flexible resilient arm arranged betwren the two rigid arms and having one end secured to said support and a free end portion extending beyond the'rigid arms which free end portion is provided with an abutment, a contact carried on each face of the flexible arm in spaced relation to its free end, one of which contacts m movable into and from engagement with one of the stationary contacts and the other being movable into and from engagement with the other stationary contact, a flexible resilient actuating lever of greater length than said arm having one end fixed to said support between the fixed ends of said rigid arms and having an elongated opening providing an abutment adjacent its free end which abutment is spaced from the abutment upon the free end portion of said arm, spring means interposed between said abutments and having suflicient force when held under compression to maintain said lever in spaced relation to said arm and one of the movable contacts in engagement with one of the stationary contacts and to stress the free end portion of said arm to force the movable contact in firm seating engagement with the stationary contact, an actuator applied to the free end portion of said lever for moving said lever toward the free end portion of said arm, and said spring means being movable with the actuating lever during movement of said lever to rock said spring means upon at least one of said abutments during movement of said lever to and beyond a critical position to change the direction of the force of said spring means to a position in which it throws the arm to be actuated in the opposite direction with a snap motion to disengage one of the movable contacts from the stationary contact with which it is engaged and to throw the other movable contact into engagement with the other stationary contact.

12. A snap acting switch comprising a support, a pair of substantially rigid arms secured to said support and extending therefrom in spaced parallel relation to each other, and each of said arms being provided on its inner face with a stationary contact, a flexible resilient arm arranged between the two rigid arms and having one end secured to said support and a free end portion extending beyond the rigid arms which free end portion is provided with an abutment having spaced inner and outer edges, a contact carried on each face of the flexible arm, one of which contacts is movable into and from engagement with one of the stationary contacts and the other being movable into and from engagement with the other stationary contact, a flexible resilient actuating lever of greater length than said arm having one end fixed to said support between the fixed ends of said rigid arms and having an elongated opening providing an abutment adjacent its free end which is spaced from the abutment upon the free end of said arm, spring means compressed between said abutments and having on portion bearing against the inner edge of the abutment on the flexible arm and being rockably mounted thereon during movement of the actuating lever and said spring means having sufficient force when held under compression to maintain the free end portion of said lever in spaced relation to the free end of said arm and one of the movable contacts on the flexible arm in engagement with one of the stationary contacts and to stress the free end portion of said arm to force the movable contact in firm seating engagement with the stationary contact, an actuator applied to the free end portion of said lever for moving said lever toward the free end portion of said arm, and said spring means being movable with the actuating lever during movement of said lever to rock said spring means upon the abutment on said arm to change the direction of the force of said spring means to a position in which a second portion of said spring means engages the outer edge of the abutment on said arm and throws the arm in a direction opposite to the movement of said lever with a snap motion to cause disengagement of one of the movable contacts from its stationary contact and engagement of the other movable contact with its stationary contact.

13. A snap acting switch comprising a support. a pair of substantially rigid arms secured to said support and extending therefrom in spaced relation to each other, and each of said arms bein provided on its inner face with a stationary contact, a flexible resilient arm arranged between the two rigid arms and having one end secured to said supports and a free end extending beyond the rigid arms which free end is provided with an abutment having spaced inner and outer edges, a contact carried on each face of the flexible arm in spaced relation to its free end, one of which is movable into and from engagement with one of the stationary contacts and the other being movable into and from engagement with the other stationary contact, a flexible resilient actuating lever of greater length than said arm having one end fixed to said support between the fixed ends of said rigid arms and having an elongated opening providing an abutment having spaced inner and outer edges adjacent its free end which abutment is spaced from the abutment upon the free end of said arm, spring means interposed between said abutments and having one portion bearing against the inner edge of the abutment on the flexible arm and a second portion bearing against the inner edge of the abutment on said lever and said spring means having suflicient force to maintain the free end portion of said lever in spaced relation to the free end of the flexible arm and one of the movable contacts on the flexible arm in engagement with one of the stationary contacts and to stress the free end portion of the flexible arm to force one of the movable contacts in firm seating engagement with its stationary contact, an actuator applied to the free end portion of said lever for moving said lever toward the free end portion of the flexible arm, and said spring means being movable with the actuating lever during movement of said lever to rock said spring means upon said abutments to change the direc tion of the force of said spring means to a position in which a third portion of said spring means engages the outer edge of the abutment on said lever to -throw it forwardly in the direction of its actuation and a fourth portion of said spring means engages the outer edge of the abutment on the flexible arm to throw the flexible arm in a direction opposite to the movement of said lever with a snap action to cause disengagement of one of the movable contacts from its stationary contact and engagement of the other movable contact with its stationary contact.

14. A snap acting switch comprising a support, a pair of substantially rigid arms secured to said support and extending therefrom in spaced parallel relation to each other and at least one of said arms being provided on its inner face with a stationary contact, a flexible resilient arm arranged between the two rigid arms and having one end secured to said support and a free end portion extending beyond the rigid arms which free end portion is provided with an abutment, a contact carried by the flexible arm in spaced relation to its free end which contact is movable into and from engagement with the stationary contact, a flexible resilient actuating lever of greater length than the flexible arm and having one end fixed to said support between th rigid arms and an elongated opening therein providing an abutment adjacent its free end which abutment is spaced from the abutment on said arm, a strip metal spring compressed between said abutments and having sufficient force to maintain said lever in spaced relation to the flexible arm and the movable contact on the flexible arm in engagement with the stationary contact and to stress the free end portion of the flexible arm which extends beyond the stationary contact, an actuator applied to the free end portion of said lever for moving said lever toward the free end portion of the flexible arm, and said sprin being movable with the actuating lever during movement of said lever to rock said spring upon said abutments to change the direction of the force of said spring to a position in which said spring throws said arm in a direction opposite to the movement of said lever to disengage the movable contact from the stationary contact and force the flexible arm into engagement with the other rigid arm to thereby limit th movement of the flexible arm.

15. A snap acting switch comprising a support, a pair of substantially rigid arms secured to said support and extending therefrom in spaced parallel relation to each other and at least one of said arms being provided on its inner face with a stationary contact, a flexible resilient arm arranged between the rigid arms and having one end secured to said support and a free end portion extending beyond the rigid arms which free end portion is provided with an abutment having spaced inner and outer edges, a contact carried by the flexible arm in spaced relation to its free end which contact is movable into and from engagement with the stationary contact, a flexible resilient actuating lever of greater length than said arm having one end fixed to said support between the rigid arms and an elongated opening providing an abutment having spaced inner and outer edges adjacent its free end, spring means compressed between said abutments and having one portion bearin against the inner edge of the abutment on the flexible arm and a second portion bearing against the inner edge of the abutment on said lever, said spring means being rockable upon said abutments durin movement of the actuating lever relative to said arm and having suflicient force when held under compression to maintain the free end portion of said lever in spaced relation to the free end of the flexible arm and the movable contact on the flexible arm'in engagement with the stationary contact and to stress the free end portion of the flexible arm which extends beyond the stationary contact, an actuator applied to the free end portion of said lever for moving said lever toward the free end portion of the flexible arm, and said spring means being movable with the actuating lever during movement of said lever to rock said spring means upon said abutments to change the direction of the force of said spring means to a position in which a third portion of said sprin means engages the outer edge of the abutment on said lever to throw it forwardly in the direction of its actuation and a fourth portion of said spring means engages the outer edge of the abutment on the flexible arm to throw the flexible arm in a direction opposite to the movement of said lever to disengage the movable contact from the stationary arm and to force the flexible arm into engagement with the other rigid arm to thereby limit the movement of the flexible arm.

16. A snap acting switch comprising a support, a pair of substantially rigid arms secured to said support and extending therefrom in spaced parallel relation to each other, and each of said arms bein provided on its inner face with a stationary contact, a flexible resilient arm arranged between the two rigid arms and having one end secured to said support and a free end extending beyond the rigid arms which free end portion is provided with an abutment having spaced inner and outer edges, a movable contact carried on each face of the flexible arm, one of which i movable into and from engagement with one of the stationary contacts and the other bein movable into and from engagement with the other stationary contact, a flexible resilient actuating lever of greater length than said arm having one end fixed to said support between the fixed ends of said rigid arms and having an elongated opening providing an abutment having spaced inner and outer edges adjacent its free end which abutment is spaced from the abutment upon the free end of said arm, a strip metal sprin having an arcuateshaped portion interposed between said abutments and having one portion bearing against the inner edge of the abutment on said lever and said spring having suflicient force to maintain the free end portion of said lever in spaced relation to the free end of the flexible arm and one of the movable contacts on the flexible arm in engagement with one of the stationary contacts and to stress the free end portion of the flexible arm to force one of the movable contacts in firm seating engagement with its stationary contact, an actuator applied to the free end portion of the flexible arm, and said spring being rockable upon said abutments during movement of said lever to change the direction of the force of said spring to a position in which a third portion of said sprin engages the outer edge of the abutment on said lever to throw it forwardly in the direction of its actuation and a fourth portion of said spring engages the outer edge of the abutment on the flexible arm to throw the flexible arm in a direction opposite to the movement of said lever with a snap motion to cause disengagement of one of the movable contacts from its stationary contact and 18 engagement of the other movable contact with its stationary contact.

17. A snap actin switch comprisin a stationary contact, a flexible arm to be actuated having a fixed end and a free end portion provided with an abutment, a contact carried by said arm which is movable into and from engagement with the stationary contact, a flexible resilient actuating lever having a fixed end and a free end portion provided with an abutment and the free end of said lever being normally biased away from the free end of said arm, spring means compressed between the abutments on said arm and said lever which spring means has sufficient force to place a stress on the free end of said lever and to maintain the movable contact in engagement with the stationary contact, and said lever being movable toward and beyond alignment with said arm when force is applied thereto to rock said spring means upon said abutments to a second position in which the force of said spring means throws said arm in a direction opposite to the movement of said lever witha snap motion, and said lever being normally biased away from said arm to such an extent that it will automatically return to its original position when the force upon said lever is released.

18. A snap actin switch comprisin a stationary contact, a flexible arm to be actuated having a fixed end and a free end portion providedwith an abutment, a contact carried by said arm which is movable into and from engagement with the stationary contact, a flexible resilient actuating lever of greater length than said arm having a fixed end and a free end portion which is normally biased away from said arm, said lever having an elongated openin therein through which the arm passes during the actuation of the switch and which is provided with an abutment at the outer edge of the opening and said lever having a portion extending beyond the opening to which an actuator may be applied, spring means compressed between the abutments on said arm and said lever which spring means ha suflicient force to stress the free end of said lever and to maintain the movable contact in engagement with the stationary contact, and said lever being movable toward and beyond alignment with said arm when an actuator is applied to its free end portion to rock said spring means upon said abutments to a second position in which the force of said spring means throws said arm in a direction opposite to the movement of said lever with a snap motion, and said lever being normally biased away from said arm to such an extent that it will automatically return to its original position when the force of the actuator upon the free end of said lever is released.

EVERARD F. KOHL.

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

UNITED STATES PATENTS Kohl Apr. 8, 1941