US2933569A - Snap-acting switch - Google Patents

Description

April 19, 1960 F. L. GLEASON 2,933,569

7 SNAP-ACTING SWITCH Filed Dec. 22, 1958 2 Sheets-Sheet 1 ATTDRNEY INVENIOR. FRANCIS L.GLEA$ON April 19, 1960 F. GLEASON 2,933,569

a SNAP-ACTING SWITCH Filed Dec. 22. 1958 '2 Sheets-Sheet 2 INVENTOR. FRANCIS L. GLEASON ATTOR NEY 2,933,569 SNAP-ACTING SWITCH Francis L. Gleason, Hornell, N.Y.

Application December 22, 1958, Serial No. 782,313

13 Claims. (Cl. 200-67) This invention relates to electric switches, and more particularly to improved snap-acting switches having quick make and quick break contacts.

=One object of this invention is to provide an improved snap-acting switch.

Another object of this invention is to provide a snapacting electric switch which has improved operating characteristics without the necessity of using precision made parts.

Another object of this invention is to provide an improved switch which requires a minimum of 'force to operate without subtracting from any of its eifectsJ A further object of this invention is to provide an improved and simplified construction for electric switches having an improved means for snapping the electrical contact member quickly from one position to another so as to minimize arcing.

To this end, a further object of this invention is to provide an improved switch having a snap-acting contact plate which makes and breaks its contacts with wiping action.

A still further object of this invention is to provide an improved switch having a snap-acting contact plate which completes the operation of the switch.

A still further object of this invention is to provide an improved switch, which is adaptable for either household "or industrial use and can be easily mounted in a switch box or socket and operated from the outside.

A still further object of the invention is to'provide an improved switch which is simple in construction, thoroughly reliable, durable, and relativey inexpensive.

Other objects of this invention will be apparent hereinafter from the specification, the drawings, and from the recital of the appended claims.

In the drawings:

Fig. 1 is a front elevation of a switch constructed according to one embodiment of this invention;

' Fig. 2 is a side elevation of the switch shown in Fig. i;

Fig. 3 is a sectional view taken at line 33 of Fig. i and looking in the direction of the arrows;

Fig. 4 is a sectional view of a modified form of switch built according to this invention;

' Fig. 5 is a side elevation of a switch built according to another modification of this invention;

Fig. 6 is a sectional view of the modification shown in Fig. 5;

Fig. 7 is a side elevation of still another modification of the invention;

Fig. 8 is a sectional view of the modification shown in Fig. 7;

Fig. 9 is a view of a contact plate which is used with the embodiments of the invention shown in Figs. 1 through 6;

Fig. 10 is a front elevation of one form of contact terminal used with this invention;

Fig. 11 is a side elevation of the contact terminal shown in Fig. 10;

" Fig. 12 is a perspective view of a modified contact 7 United States Patent '0 ice plate used with the embodiments of the invention shown in Figs. 7 and 8;

Fig. 13 is a front elevation tact terminal;

Fig. 14 is a side elevation of the contact terminal in Fig. 13;

Fig. 15 is a fragmentary view showing a modified contact plate and the spring-loaded ball cooperating therewith;

Fig. 16 is a fragmentary View showing particularly the ball of the modified contact plate of Fig. 15; and

Fig. 17 is a fragmentary view of still another modified configuration of contact plate and terminal showing in dotted lines the wiping action of the contact plate as it moves over the terminal to the contact-breaking point.

In the embodiments herein disclosed there is a movable operating member having a U-shaped contact plate pivotally attached thereto with the arms of the contact plate engaging terminals that are attached to a supporting or insulating block. Disposed between the arms of the contact plate and carried by the insulating of a modified form of conmember is a spring-pressed ball which engages'thecros'sbar of the contact plate.

When the operating member is in one of its positions, the ball holds the arms of the contact plate in contact with the terminals. As the operating member is moved from that position, the crossbar of the contact plate rides over the spring-pressed ball so that its arms'have a Wiping movement against the terminals, with which they have been engaged, while still maintaining contact therewith; and then the ball snaps the arms of the contact plate away from the terminals to pivot the contact member instantaneously to its other position. If the switch is a single pole switch, this other position will be of the ofi position of the switch. if the switch is a double pole switch, the contact plate will be in contact with another pair of terminals in this other position.

Referring to the embodiment shown in Figs. 1-3, the switch comprises an insulating or mounting block 10, which has two pair of terminal plates 12 mounted therein. The insulating block 16 may be formed from a single piece of insulating material such as porcelain, plastic, or even wood. The block it is generally cubical in configuration, and has two parallel lateral recesses 16, which extend from the front of the block to the rear. A cylindrical chamber 18, which is open at one end, is formed between the recesses 16 in the central portion of the insulating black 10. The chamber 18 is adapted to hold a ball 13 which is supported by a helical spring 14 that is interposed between the bottom of the chamber and the ball.

Each side of the insulating block 10'is provided with two vertically-extending slots 21, as viewed in the drawings, which are adapted to hold the terminal plates 12. The slots extend inward from the top and bottom surfaces of the insulating block 10, as viewed in the drawings, and intersect the recesses 16.

Each terminal plate 12 is right angular in shape. :Its long leg fits in a portion of a respective slot 21, while its short leg lays fiat against a sidewall of the associated recess 16. Nut and bolt assemblies 23 which are mounted in bores 22, secure the terminals 12 in position in the slots 21, and are adapted to be electrically connected to an external circuit.

block across the recess 26, to fit into the respective guide slots 27 in the member 25. 'The pins 28 serve to hold the actuating member 25 slidably against the front. surface of the insulating block it? and also act as stops for the member 25.

A generallyv U-shaped rigidcontact plate 35 (Fig. 9)

is provided, to bridge theterminal' plates 12 This plate has spaced arms 36 which are connected by a cross member 37. This cross member has a pivot PIQfiCfiGIl 38 which loosely tits in a recess :9 (see Fig. .3) formed in the operating member 25 to permit limited pivotal b31133 is. urged by the spring 14 against a V-shaped groove 3t? formed in the inside edge of the cross member. 37 midway between the arms 36.

When the member 25 is operated from the position as shown in Figs. 1 and 2 to the position as shown in Fig. 3, the contact plate 35, whose arms 36 are in contact with the upper terminals 12 in the position of Fig. 2, compresses the spring 14 riding over the ball 13.

In this action thearms 36 have a. wiping movement across the upper pair of terminals 12. When the contact plate 35 has'moved far enough on the surface of the ball, the bait pivots the contact plate relative to the operating member, thus causing the arms 36 to snap away from the contact portions 17 of the upper pair of terminal plates 12, and snap into contact with the portions 17 of the lower pair of terminal plates 12.

As the projection 33 of the plate 35 is adapted to pivot in the opening 39 of the actuating member 25, the snapping action of the plate is not aiiected by the frictional resistance of the member 25 sliding on the surface of the block 143. In other Words, the snapping action does not carry or cause the member 25 to move in either direction with the contact plate 35. This permits the entire force of the spring and ball action to' move the contact plate 35 only, which permits not only a much quicker action, but allows a shorter and weaker spring to be'used. The wiping action of the arms 36 against the faces 17 of the terminal plates 12 reduces arcing and also helps maintain the contacts tree of any foreign, matter which would prevent proper electrical contact.

The distance betweenthe fulcrum formed by the projection 33 in the opening 39, and the surface 30 on which the ball 18 bears, is less than the length of the contact arms 36', so that the ends of the contact arms snappingly move a greater distance than the cross-bar 38, thereby providing a distinct lever advantage.

Referring to the modifications shown in Figs. 4, 5 and 6, 4% denotes an insulating block, which is generally cubical in configuration, and which has recesses 42 formed in its sides similar to the recesses 16 of the previous embodiment. A chamber 43, which holds the ball 13, is fo'rmedin the block 46 between the recesses 16. The block 4 3 has an enlarged opening 45 which communicates with the chamber 43. An operating member 5-9, which has spaced legs 5i'that straddle the block 49, is pivotally mounted on the block by a pin such as indicated at 52 in Fig. 4 and at 56 in Figs. 5 and 6. The member 59 has an opening 53 in its underside mid.- way between its arms 51, vfor loosely receiving the pivot projection 38 of the contact plate 35. a

In these modifications, chamber 19 has side walls 46 1 which limit, the movement of the member 56. The

modifications in Figs. 4, 5 and 6 are shown as being pro.- vided with the one pair of terminal plates 12, each of which is inserted in a groove 21 (Fig. 5) and secured by a nut and bolt assembly 23, which is inserted in one of the pair of bores 22 similar to the embodiment heretofore described in connection with Figs. 1 through 3.

Referring specificaliy to the modification in Fig. 4, the actuating member 56 is pivotally attached by means of a pivot pin 52 to the block 40 in axial alignment with the chamber 18. The pivotal operation of'the member 5% causes the contact plate 35 ;to move in an arc up and over the ball 13. diluting the arcuate movement of the member 5%, theplate 35 forces. the. ball 13 into its chamber 18 against the pressure of the spring 14 until the force of the spring 14 causes the plate 35 to pivot about its projection 38, thereby snapping the contact arms 36 into or out of engagement with the faces 17 of the contact terminals 12 depending upon the direction in which the operating member 51 is moved. In leaving the terminals 12, the arcuate movement of the plate 35 causes its arms 36 to wipe the contact terminals 12.

'12. This results in an increased wiping action of the arms 36 against the faces 17 of the members 12 and further reduces any tendency to arc or pit.

Referring to the modification. shown in Figs. 7. and 8, the switch comprises an insulatingblock 60 which supports a pair of terminals 61. Theinsulating block 60 is generally cubical in configuration, and has a sloping recess 64 in each of its sides. A cylindrical chamber 63 is formed'in the central portion of the block 60-at an angle to the recesses 64 and midway between the recesses. The chamber 63 communicates with an enlarged opening 66 in the front of the block 60. The insulating block 60 has a shoulder 62 on each of its sides, which forms part of the front wall of the associated recess 64. Each of the terminals 61 is secured to a shoulder 62 by a nut and bolt assembly67. The bolt of each assembly extends through a bore 68 in theblock 60. Each assembly is adapted to be connected. toan external circuit which is controlled by the operation of the switch.

The contact surface 69 0f each terminalGl is provided with a slot 89, the purpose of which will be described in connection with the operation of this modification of the invention. An actuating member .70 having spaced parallel arms 71, which are bent at an angle, is pivotally attached to the block 60 at 72 towards the upper side thereof as viewed in Figs. 7 and 8 away from the contact surfaces 69 of the terminal plates 61. A contact plate '75 (see Fig. 12) which is of general U-shape, but which has its arms bent, is provided to bridge the terminals 61. The cross member 77 of this plate, as in the preceding modification,'has a pivot projection 78 loosely fitting into The contact plate 75 may be formed of a single piece of metal, such as brass; and is interposed betwecn'the member and the insulating block 60 with each one of its arms76 extending into a respective slanting recess 64. Again the contact member rides on a ball'13. The ball 13 is urged by the spring 14 against a V-shaped groove 81 in the cross member 77 midway between the bent arms 76. 7

When the actuating member 70 is pivoted upward, as viewed in Figs. 7 and 8, theplate, swings upwardly. Because of the otis'et of the pivot point 72 with respect to notch 81, the arms 76 of the plate 75 wipe across the surfaces 69 of the terminal plates 61 before the contact plate 75 snaps out of contact with these surfaces, and then make a quick break. As the arms 76 wipe across the surfaces 69, the gap 89 further reduces the arcing tendency when the contact plate 75 snaps away from the ass-5.56s

terminals. The slant of the arms 76of the cont actplate;

the bend in the arms 71, and the offset of pivot'72 all contribute to making the contact plate snap more quickly and more easily from one position to the other. Once the lever 71 is started, the ball and spring automatically carry the contact plate on to the end of its movement. Moreover, the offset of the pivot point 72 and the bend in the arms 71 and the bend in the plate 75 shortens the distance of throw required for the switch to effect the breaking action. Thus, less travel of the plate is required during operation of the switch All these things contribute to making the switch of the present invention suitable for use in any application requiring a control switch, whether manually or automatically actuated If desired, contact terminals 61 might be provided on the same side of the recess 64 as the pivot 72, thus providing a quick make instead of a quick break, thus utilizing the momentum ofthelever 71 to carry the lever on to make the contact instead of effecting the break As shown in Figs 15 and 16 instead of mounting the ball and spring directly in a chamber in the block10, 40 or 60, the ball and spring may be mounted in a bushing 101 which has arms 105. A modified form of contact plate 106 having its arms in a single plane and having a recess 107, the edges of which ride on the ba'l 13, is shown in operative engagement with this ball. This type of contact plate with a recess to receive the ball may be used where a greater degree of offset of the trip lever is desired. The edges of the recess 107 make contact with the ball at points displaced from the zenith of the ball. The plate 106 travels, therefore, in a smaller arc than if the plate had contact with the ball at its zenith, thus further shortening the distance of travel required for operation of the switch.

In Fig. 17, a further embodiment of the invention is shown in which a contact plate is provided which has an arm 110 which has a lower bent portion 112 in engagement with a terminal 114 which has a slanting face 115. With this modification, the surface of the portion 112 will have full wiping contact with the face 115 prior to snapping out of engagement with the terminals. It is apparent that this construction of contact plate and of terminals, when used in an embodiment such as shown in Fig. 7 and Fig. 8, will permit further decrease in the are which the lever 71 has to travel to trip the switch. With this construction, moreover, the pivotal point of the ball at theoretical neutral position can be closely aligned with the central plane of the chamber which contains the ball, thus making it possible for the ball, upon the slightest movement of the trip lever, to snap the contact plate from one position to the other.

It is apparent that the pivot point may be offset to a greater or lesser degree, and also that the inclination and contact surfaces of both the contact plate and the terminals can be varied.

It is understood that the terminal 61 having the groove 89 may be used in all the modifications shown herein, and that the contact plates 35 and 75 may be formed with more than two extending contact arms 36 and 76.

While the invention has been described in connection with several difierent specific embodiments thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as fall within the scope of the invention or the limits of the appended claims.

Having thus described my invention, what I claim is:

1. A snap-acting switch comprising a support, a pair of terminals attached to said support, an operating member movably mounted on said support, a contact plate pivotally connected adjacent one edge to said operating member, a spherical member mounted in said support,

6 and spring means constantly urging said: spherical member against an opposite edge of said contact plate to hold said plate in engagement with said terminals when said operating member is at one limit of its movement in one direction, said operating member being movable in the opposite direction to move the pivot of said contact plate thereby to move said contact plate over said spherical member against the resistance of said spring, whereby said palte will first wipe along said terminals and then snap out of engagement with said terminals. 7

2. A snap-acting switch comprising a support, a pair of terminals attached to said support, an operating member pivoted on said support, a contact plate for engaging said terminals, said contact plate being pivoted to said operating member adjacent one edge of said contact member and at a point spaced from the pivot of said operating member, a ball mounted on said support, and spring means constantly urging said ball against an opposite edge of said contact plate, whereby upon pivotal movement of said operating member the pivot of said plate will be moved, and said plate will first wipe along said terminals, and will then snap out of engagement with said terminals.

3. A snap acting switch comprising a support, a pair of terminals attached to said support, an operating member pivoted to said support, a contact plate having a pair of integral, spaced, parallel arms for engaging said terminals, said contact plate being pivoted to said actuating member at one edge thereof at a point spaced from the pivot of said operating member, a ball movably mounted on said support, and spring means constantly urging said ball against the opposite edge of said contact plate between said arms, whereby upon pivotal movement of said operating member the pivot of said contact plate will be moved and said arms will first wipe along said terminals, and will then snap out of engagement with said terminals.

4. A snap acting switch comprising a support, a pair of terminals attached to said support, said support having a chamber therein, an actuating member movably mounted on said support, said actuating member having a recess therein, a U-shaped contact plate having spaced arms integrally connected by a cross member, means for pivotally mounting the contact plate on said actuating member, comprising an integral projection extending from said cross member in the opposite direction from said arms, the end of which extends into said recess, means for causing said arms to wipe the terminals and snap out of engagement therewith upon the movement of the actuating member in one direction and snapping into engagement with said terminals upon the movement of the actuating member a predetermined distance in the other direction, comprising a ball disposed in said chamber and spring means constantly urging the ball against the cross member intermediate said arms.

5. A device according to claim 4 wherein the cross member has a notch disposed centrally thereof to center the contact plate relative to said terminals.

6. A device according to claim 4 wherein said actuating member is slidably movable'on said block.

7. A device according to claim 4 wherein said actuating member is pivotally attached to said block.

8. A device according to claim 4 wherein each of said terminals has a transversely slotted contact portion.

9. A snap acting switch comprising a support, said support having a chamber therein, a pair of terminals attached to said support at one side of said chamber, an actuating member pivotally attached to said support on the opposite side of said chamber, a contact plate pivotally mounted on said actuating member and movable therewith, said plate having a pair of arms bent in the direction of the terminals for engaging said terminals, means causing said arms to wipe the terminals and snap out of engagement therewith upon the movement of the actuating member in one direction and snap into engageaaaaraa ment with said terminals upon the movement of the actuating member in the other direction,'comprising a ball disposed in said chamber and spring means constantly urging said ball against'the contact plate intermediate said arms.

10. A device according to claim 9 wherein the actuating member has spaced arms, said arms being bent intermediate their ends. l

11. A snap acting switch comprising an insulating block, a spherical member movably mounted on said insulating block, spring means urging said spherical member in a given plane from one surface of said insulating block, a pair of terminals attached to said insulating block atone side of said plane, an operating member having a cross bar, said operating member having an arm, con? nected to said cross bar and pivotally attached to said insulating block on the other'side of said plane, a contact plate having spaced extending arms connected by across member, said cross member portion of the contact plate being pivotally mounted on said operating member, said cross member engaging the surface of said spherical member, said spring means urging said'sp herical member to. engage, said cross member to hold the arms of said contact plate. in engagement with said terminals when said cross bar of said operating member is positioned'to the one side, of said given-plane, said. operating member being pivotal to intersect said plane to increase the linear distance between said terminals and the cross member of said contact plate, said spring means first causingthe arms of said contact plate to wipe against said terminals and then to pivot said contact plate to snap said arms out of engagement with said .terminals.

12. A device according to claim 11 wherein the arm of said operating member is bent intermediate the cross bar and its end. e 7

13. A device according to. claim 11 wherein the arms of the contact plate are bent intermediate their ends.

References Cited in the file of this patent FOREIGN PATENTS Great Britain Dec. 19, 1935, France r Nov. 28, 1928

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