US3610857A

US3610857A - Pulse-producing snap action switch

Info

Publication number: US3610857A
Application number: US868083A
Authority: US
Inventors: Robert N Nanninga
Original assignee: Industrial Electronic Hardware Corp
Current assignee: Industrial Electronic Hardware Corp
Priority date: 1969-10-21
Filing date: 1969-10-21
Publication date: 1971-10-05
Anticipated expiration: 1988-10-05

Abstract

A snap action switch comprises actuating means operatively connected to a base member and movable from a first position to a second position, a first electrical contact operatively connected with the actuating means and movable therewith from a first to a second position, and a second electrical contact engageable by the first contact at the second position thereof. A resilient member which engages the actuating means carries the first contact with the actuating means until the first and second contacts engage. At this point the resilient member is flexed and released from the actuating means for a period sufficient for a spring to cause the first contact to disengage from the second contact and to snap back to its first position.

Description

United States Patent 2 1 t Robert N. Nannin 3 2,904,661 9 1959 Roeser 200/160 [7 1 men or Canoga Park, Cali f. 3,062,071 1 1/1962 Morrow... 200/160 X [21] APP] 868,083 3,117,199 1/1964 Millerwise 200/77 [22] Filed Oct. 21, 1969 FOREIGN PATENTS Patented 5, 1971' 962,745 7/1964 Great Britain zoo 153.22 [73] Assignee Industrial Electronic Hardware Corp.

New York Primary Examiner-H. 0. Jones Assistant Examiner-Robert A. Vanderhye Attorney-James and Franklin [54] PULSE-PRODUING SNAP ACTION SWITCH 20 Cl 15 Dr in Fi s.

anus aw g g ABSTRACT: A snap action switch comprises actuating means [52] US. Cl 200/160 operatively connected to a base member and movable from a 1 f 13/52 first position to a second position, a first electrical contact [50] Field of Search 200/160, operatively connected with the actuating means and movable 166 PC; 74/470 therewith from a first to a second position, and a second electrical contact engageable by the first contact at the second [56] References C'ted position thereof. A resilient member which engages the ac- UNITED STATES PATENTS tuating means carries the first contact with the actuating 2,347,874 1944 ml n 200/77 means until the first and second contacts engage. At this point 2,215,124 1940 (06k 6! 8| Jim/166 CPC UX the resilient member is flexed and released from the actuating 2,420,913 5/1947 Schellman ZOO/77 means for a period sufficient for a spring to cause the first con- 2.722,579 1 1955 ROhaCS ZOO/150 X tact to disengage from the second contact and to snap back to 2,748,216 5/1956 Schneider et al. 200/77 i fi t iti n.

PULSE-PRODUCING SNAP ACTION SWITCH This invention relates to electrical switches, and more specifically to a snap-action switch designed to produce an electrical signal in the form of a pulse.

Recent developments in the electronics field, particularly in computer technology, have produced highly advance electrical switches. The electrical switching in these devices occurs at seeds in the order of nanoseconds. Such switching speeds are necessary for the proper operation of the high-speed computers. This fast switching is effected in electrical circuits without the use of any moving mechanical parts by means of such devices as semiconductors arranged in various gating circuits. Fast speed switching in electromechanical and mechanical devices is considerably slower than in electronic devices.

Despite the slow speed of mechanical switches, there are still a wide variety of applications in which such switches are important. One example is an electric typewriter in which printing is directly related to the actuation of an electromechanical switch by manual means, such as the depression of a typewriter key. As is well known, an electrical typewriter converts the mechanical displacement of a key into an electrical pulse signal which is then reconverted into a mechanical movement, i.e., printing. It is imperative in this type of device that the components which are employed be capable of fast operation. Obviously, the speed at which the complete printing operation occurs is limited by the mechanical movement of the various parts in the system.

Even though some mechanical switches have been developed which are capable of operating to produce electrical pulses quickly, the quality of the pulse is often adversely affected by vibrational conditions during the operation of the switch. Thus it is not uncommon for switches of the type now available to produce double pulses or half pulses because of the vibrational shock experienced by the switch during its operation. In addition, the presently available high-speed switches are usually quite complex and are expensive to manufacture.

It is the primary object of this invention, therefore, to provide a switch which quickly and accurately produces an electrical pulse in response to a mechanical movement.

It is another object of this invention to provide a switch which is relatively insensitive to vibrational shock during the operation of the switch.

It is still another object of this invention to provide a snap action switch which when once actuated, quickly and automatically resumes its initial operative position so as to be prepared for the next operative cycle.

A further object of this invention is to provide a snap-action switch which is adapted to be easily mounted on a printed circuit board.

Broadly the snap-action switch of the invention comprises a base member, actuating means operatively connected to the base member and movable for a first position to a second position, first electrical contact means operatively connected in holding engagement with the actuating means and movable therewith from a first to a second position and second electrical contact means engageable by the first electrical contact means when the latter is moved to its second position, thereby to close an electrical circuit. Means operatively connected to the actuating means is effective to release the first contact means from holding engagement with the actuating means when the first and second contact means are engaged. At this point, snap means causes the first contact means to be snapped out of engagement with the second contact means and restored to its first position. v

The release of the first contact means from the actuating means and the return of the first contact means to its first position occurs at an extremely fact rate promptly after the first and second contacts engage. The actual engagement and disengagement of the first and second contact means occurs in a period of approximately 4 milliseconds. The restoration of the first contact means automatically to its original position enables the switch immediately to be in a condition to be actuated again. Thus, the switch is most advantageous for use in a device such as an electrical typewriter or the like.

As here described the means to release the first contact from the actuating means comprises a resilient member resiliently operatively connected between the first contact means and the actuating means. Means also operatively connected to the actuating means is effective to flex the resilient member upon the engagement of the first and second contact means thereby to release the resilient member from the actuating means. The release occurs for a period sufficient for the snap means to snap the first contact means out of engagement with the second contact means the back to its first position. in one form of the invention, the resilient member comprises first and second parts and a spring effective to urge the parts into engagement with the actuating means. In this form of the invention, means such as an abutment on the actuating means is provided for separating the spring held parts so that they are released from the actuating means. The abutment passes through an annulus formed by the parts upon continued advancement of the actuating means and thereby causes the parts to be spread apart and to be temporarily disengaged from the actuating means. The snap means such as a spring then snaps the first contact out of engagement with the second contact. The separated parts are carried with the first contact, and thereafter again resiliently engage the actuating means when freed from the abutment.

In another embodiment of the invention the actuating means comprises a rod having a notch on its periphery. The resilient member comprises a spring seated in the notch and carried with the rod from a first position to a second position. At the second position, that is, when the first contact engages the second contact, the spring is dislodged from the notch by being expanded. The first contact which was carried to the second position by its engagement with the spring is then free to move relative to the rod and is snapped back to its first position. The expansion of the spring occurs as a result of the rod continuing its advancement beyond the position at which the first and second contacts engage. The continued advancement of the rod enables the upper part of the notch in which the spring is seated a pass through the central portion of the spring, thus expanding the spring and dislodging it from the notch.

In still another embodiment of the invention, the actuating means comprises a rod and the fist electrical contact comprises a circular plate resiliently held to the periphery of the rod by a plurality of radial springs urging the plate into contact with the rod. In the preferred form, the springs are placed in radial grooves within the plate, and are attached to rollable members at one end. The rollable members are urged into a peripheral notch in the rod by the springs with sufficient pressure to cause the plate to be carried with the rod from the first to the second position. At the second position the plate engages and is stopped by the second contact means. Upon engagement of the first and second contacts, the rollable members are dislodged from the notch and the plate advances axially along the rod opposite to the direction of the continued advancement of the rod. This axial movement of the plate occurs as a result of a compressed spring acting on the plate. In this manner, the plate is immediately disengaged from the second contact and restored to its first operative position.

in an additional embodiment, the pulse-producing snap switch is structured for mounting on a printed circuit board. For this purpose, the housing of the unit includes a plurality of pronged extensions which are adapted for snap insertion into receptacles in the printed circuit board. The board is provided with a recess to receive the advancing actuating means and to removably receive a snap return spring which is operatively attached to the first contact means.

To the accomplishment of the above, and to such other objects as may hereinafter appear, the present invention relates to the construction of a snap-action switch as defined in the appended claims, and as described in this specification taken together with the accompanying drawings in which:

FIG. 1 is a front elevational view in cross section of one embodiment of a snapaction switch;

FIG. 2 is a similar cross-sectional view of the switch of FIG. 1 shown with the actuating mechanism in an advanced position;

FIG. 3 is a similar cross-sectional view of the switch shown in FIGS. 1 and 2, and illustrates a further operative position of the switch during the operating cycle;

FIG. 4 is still another similar view to that shown in FIGS. 1 through 3, and illustrates the return of the actuating mechanism to its original position;

FIG. 5 is a cross-sectional view of the switch shown in FIGS. 1-4 taken on lines 5-5 of FIG. 3;

FIG. 6 is a front elevational view in cross section of another embodiment of a snap-action switch;

FIG. 7 is a similar cross sectional view of the switch in FIG. 6 with the actuating mechanism in an advanced position;

FIG. 8 is a similar cross-sectional view of the switch shown in FIGS. 6 and 7 and illustrates a further operative position of the switch during the operating cycle;

FIG. 9 is still another cross sectional view of the switch shown in FIGS. 6, 7 and 8, and illustrates the return of the actuating mechanism to its original position;

FIG. 10 is a cross sectional view of the switch illustrated in FIGS. 6-9 taken on the line l0--10 of FIG. 9;

FIG. 11 is a front elevational view in cross section of still another embodiment of a snap-action switch;

FIG. 12 is a fragmentary cross-sectional view of the switch shown in FIG. 11 with the actuating mechanism in an advanced position;

FIG. 13 is a front elevational view in cross section of still another embodiment of a snap-action switch;

FIG. 14 is a cross-sectional view of the switch illustrated in FIG. 13 with the actuating mechanism in an advance position; and

FIG. 15 is a cross-sectional view taken on lines 15-15 of FIG. 13.

The electrical switch of the invention may be fully understood by referring to the drawings wherein several embodiments are shown in several operative positions. The four switch embodiments shown are separately illustrated in FIGS. 1 through 5, FIGS. 6 through 10, FIGS. 11 and 12, and FIGS. 13 through 16. All of the switches illustrated operate substantially in the same manner. An actuating means, generally designated by the numeral 10, is operatively connected to a base member 12. A first electrical contact means designated generally by the numeral 14 engages the actuating means 10 through a resilient member 16. A second electrical contact means 18 is also operatively connected to the base 12 and positioned to receive the first contact means 14 to provide an electrical connection therewith. A snap means 20 is operatively connected to the contact means 14. In the operation of the switch, the first contact means 14 is carried with the actuating means 10 and the resilient member 16 to the position of engagement with the second contact means 18. Immediately upon the contact of these parts, the snap means 20 causes the first contact means 14 to be snapped back to its original position. The force of the snap means is rendered effective to provide this result because the resilient member 16 is flexed out of engagement with the actuating means 10 just as the first and second contact means engage, thereby releasing the first contact means from connection with the actuating means.

Referring now to the embodiment of FIGS. 1 through 5, the actuating means 10 is there shown as a rod 22 which is attached to a button 24 and is telescopically fittedwithin a housing 26. As illustrated, the rod 22 encloses and is slidably mounted about a fixed post 28. A bore 30 is provided in the central portion of the rod 22 so that the rod may advance along the post 28 as shown in FIG. 2. The first electrical contact means 14 is shown in the form of a circular plate 32 which surrounds the rod 22. The plate 32 is provided with

conductive strips

34 and 36 which are attached to the lower surface 38 thereof. The upper surface 40 of plate 32 engages the resilient member 16 which comprises

parts

42 and 44 urged into an undercut portion 46 of the rod 22 by a spring 48. The resilient engagement of these

parts

42 and 44 with the rod 22 causes the parts to be carried with the rod as it advances from its first or elevated position shown in FIG. I to a second or depressed position shown in FIG. 2. Consequently plate 32 is also carried with the advancing rod as shown in FIGS. 2 and 3 until the second contact means l8is engaged. The second contact means 18 is here shown as

electrical terminals

50, 52 54 and 56 (FIG. 5). The

terminals

50, 52, 54 and 56 are connected to the base member 12, project upwardly therefrom into the path of the plate 32, and act as positive stops for the latter. The lower portions of these terminals, such as at 58 and 60 (shown fragmentarily) may be electrically connected in any well-known manner to a suitable circuit. As illustrated in FIG. 5 the conductive strips 34 and.36 electrically join ter minals 50 and 52 and

terminals

54 and 56 respectively when engaging these terminals. In this manner electrical components connected to these terminals may be briefly joined together or may receive an electrical pulse which is transmitted through the connections formed by the

conductive strips

34 and 36 and the various terminals. It will be understood that in this and other embodiments the number and arrangement of contacts and conductive strips as illustrated are merely by way of example, and may be widely varied.

The snap means 20 illustrated in FIG. I is shown as a spring 62 which is attached at one end to a flanged member 64 and at the other end is received in a recess 66 in base 12. The flanged member 64 is attached to the lower surface of the plate 32 and therefore the spring 62, as it is compressed by the advancing actuating rod 22, exerts a force on the plate 32. However, the force exerted by the spring 48 on the

parts

42 and 44 is sufficient to hold those parts within the undercut rod portion 46, and hence the contact plate 32 moves with the rod 22 as the latter is depressed until the contact means 14 and 18 engage, as shown in FIG. 2. Further advancement of the rod 22 beyond this engaging position, as illustrated in FIG. 3, causes the abutment 68 at the upper portion of the undercut section 46 to pass into the central opening 70 formed by the

parts

42 and 44 of member 16 (FIG. 5). Since the abutment 68 is of a greater width than the diameter of the opening 70, the

parts

42 and 44 are caused to separate. While the force of the spring 48 is still effective to urge the

parts

42 and 44 against the rod, this force is no longer sufficient to overcome the force of spring 62 primarily because the member 16 is now dislodged from the undercut rod portion. As a result the plate 32, and more specifically, the

conductive strips

34 and 36 are snapped up out of engagement with the

terminals

50, 52, 54 and 56 respectively, as shown in FIG. 4. The spring 62 continues to force the plate 32 and the resilient member 16 upward until the resilient member is stopped by the flange 72 on the upper portion of the rod 22. At this point the resilient member 16 and the plate 32 are restored to their original position. Continued advancement of the rod 22 performs no further function in the operation of the switch. A spring 74 is concentrically positioned within the spring 62 and operatively connected between the rod 22 and the base 12. This spring is employed to restore the rod 22 to its original position upon the removal of the actuating force from the button 24. When this occurs the undercut rod portion 46 returns to registration with the

parts

42 and 44, which are then urged into portion 46 by spring 48. The switch is then in a condition to again be actuated.

Because of the force provided by the snap means 20, the actual engagement time of the

conductive strips

34 and 36 and the

several terminals

50, 52 54 and 56 is only in the order of a few milliseconds. Thus, the actuating means is forced downward at a rate of speed depending upon the applied force, but the disengagement of the contact means 14 occurs substantially immediately after engagement with the contact means 18 and is independent of the position of the actuating means 10 after the engagement has been achieved.

Another embodiment of the switch of the invention is shown in FIGS. 6 through 10. As there shown the rod 22 of the actuating means is operatively connected to the plate 76 which is attached to the button 24. A spring 78 is affixed at one end to the plate 76 and at the other end to a shoulder 80 in a housing 26. A concavely formed notch 82 is provided on the periphery of the rod 22. The resilient member 16 here com prises a garter spring 84 which normally surrounds rod 22 and is seated in the notch 82. A keeper member 86 is affixed to the upper surface 40 of plate 32 and partially surrounds the garter spring 84.

A conductive strip 34 is here shown positioned on upper surface 40 of plate 32. This strip 34 engages third electrical contact means shown as

terminals

88 and 90 when this plate 32 is in its upper position as shown in FIGS. 6 and 10. Contact means 18 comprises terminals 92 and 94 (FIG. 1.) which are supported in base 12 and project upwardly therefrom. All of these terminals may be connected at the

lower portions

96 and 98 with external circuitry.

As illustrated in FIG. 7, when the rod 22 is caused to move downwardly the garter spring 84 and keeper member 86 are efi'ective to carry the plate 32 into contact with the terminals 92 and 94. The movement of the plate 32 causes the strip 34' to be disengaged from the

terminals

88 and 90. In the illustration of FIG. 8 the rod 22 has been advanced farther than the position shown in FIG. 7 and as a result the spring 84 has been dislodged from the notch 82. At this point, the force provided by the spring 82 is less than the force provided by the snap spring 62 and hence the plate 32 is caused to snap out of engagement with the terminals 92, 94 and to return to its original position, as shown in FIG. 9. The snap action provided by the spring 62 occurs very quickly after the engagement of terminal strip 36 and terminals 92 and 94. The time of contact is sufficient for a pulse of electrical current to pass through the terminals to associated electronic equipment, not shown. As shown in FIG. 9, the conductive strip 34 again contacts the

terminals

88 and 90 when returned to its original position. Upon a release of the force from button 24, the rod 22 returns automatically to its original position due to the force provided by spring 78 and the spring 84 reestablishes itself in the notch 82. Thus, the switch again assumes the operative condition shown in FIG. 6.

FIG. 11 and [2 illustrate still another embodiment of the switch of the invention. The component parts of the switch have been similarly numbered with those parts illustrated in the other drawings and particularly in FIGS. 6-10. The singular differentiating feature of the switch in FIGS. 11 and 12 from that shown in FIGS. 6-10 is the convex projection 100 which is positioned on the periphery of the rod 22. As illustrated in FIG. 11 the garter spring 84 is positioned below the projection 100 as the rod 22 moves downwardly. Upon engagement of the conductive strip 36 and terminals 92 and 94, the continued advance of the rod 22 causes spring 84 to be expanded by the projection 100, since further movement of the plate 32 is prevented by terminals 92 and 94. The force provided by the compressed spring 62 then snaps the plat 32 to its original position. Release of the actuating force from rod 22 causes the rod 22 to assume the first operative position as shown in FIG. 11.

FIGS. 13, 14 and 15 illustrate still another embodiment of the switch of the invention. The base member 12 is here shown as a printed circuit board 102 having several

conductive areas

104 and 106 exposed at the upper surface 108. The

conductive areas

104 and 106 provide electrical contacts which are adapted to receive the

contacts

34 and 36 which are positioned on the lower surface 38 of the plate 32. The plate 32 is operatively connected to the carrier section 110. A plurality of

springs

112, 114 and 116 are radially positioned in grooves formed by the plate 32 and section 110 and extend toward the rod 22. A plurality of

rollable embers

118, 120 and 122 are positioned at one end of the

springs

112, 114 and 116 and are seated in the concave notch 124 in rod 22. Each of the springs is held against the rollable members by means of a plug such as at 126, 128 and 130 and the assembly of springs, rollable members and plugs thereby comprise the resilient member designated generally by the numeral 16.

A large recess 132 is formed in the circuit board 102 to receive the rod 22 when it is advanced to the position shown in FIG. 14. A snap spring 62 is received at one end in a recessed portion 132 and at the other end engages the lower surface 38 of the plate 32 such as by means of a suitable adhesive or the like.

A plurality of

pronged extensions

134, 136 and 138 project from the housing 26 and are adapted for snap insertion into the

receptacles

140, 142 and 144 respectively on the printed circuit board 102. With this structure, the switch is readily mounted on and removed from the printed circuit board 102.

When the switch is mounted on the circuit board 102 the spring 62 is received in the recess 132 and is slightly compressed against the bottom wall 146. This spring 62 is carried with the switch when it is removed from the circuit board 102 due to its engagement with the contact plate 32.

The operation of the switch illustrated in FIGS. 13, 14 and 15 is substantially similar to the operation of the other switch embodiments hereinbefore described. The

rollable members

118, and 122 are dislodged from the notch 124 in response to the advance of the rod 22 beyond the position at which the

contacts

34 and 36 on plate 32 form an electrical connection with the

contacts

104 and 106 on circuit board 102. As the rod advances beyond this position of initial engagement, the

rollable members

118, 120, 122 assume the position illustrated in FIG. 14. The snap spring 62 then forces the plate 32, carrier section 100, and the springs, rollable members and plugs to travel in a direction opposite to the advance of the rod 22. As a result, these members again assume the position shown in FIG. 13. Spring 78 then acts to restore the rod 22 to its original position.

It will be appreciated that while the description has been limited to several embodiments a wide variety of modifications in the switch of the invention may be made. Terminal engagements shown or suggested in one embodiment may be used in a different embodiment. The specific structural means utilized for the various operative parts may be widely varied. Additional electrical connections may be utilized with various terminals which may be connected to any suitable circuitry. Multipole switches may readily be provided by a variation in the position of the terminals and size of the conductive strips. It will be apparent that many other variations may be made, all without departing from the spirit of the invention.

Iclaim:

1. A snap-action electrical switch comprising a base member, actuating means operatively connected to said base member and movable from a first position to a second position, first electrical contact means operatively connected in holding engagement with said actuating means and movable therewith from a first to a second position, second electrical contact means at said second position of said first contact means and for receiving said first contact means in an electrical connection upon engagement therewith. means operatively connected to said actuating means and effective to release said first contact means from holding engagement with said actuating means when said first contact means engages said second contact means, and means to snap said first contact means out of engagement with said second contact means upon the release thereof from said actuating means.

2. The switch of claim 1, in which said release means comprises a resilient member operatively connected to said first contact means and resiliently engaging said actuating means, and means operatively connected to said actuating means and effective to fiex said resilient member upon the engagement of said first contact means with said second contact means, thereby to release said resilient member from said actuating means for a period sufficient for said snap means to snap said first contact means out of engagement with said second contact means.

3. The switch of claim 2, in which said resilient member comprises a member having two parts and spring means operatively connected to said parts and effective to urge said parts into engagement with said actuating means and said flexing means comprises means for separating said parts from said actuating means upon the engagement of said first and second contact means. I

4. The switch of claim 3, in which said actuating means comprises a rod and said parts form an annular member enclosing said rod, and in which said separating means comprises an abutment on said rod in engagement with said parts and effective to carry said parts and said first contact means with the rod from said first position to said second position, said abutment also being effective to separate said parts upon the engagement of said first and second contacts by passing into the annulus of said annular member upon the continued movement of said rod.

5. in the switch of claim 4, means operatively connected to said rod and effective to return said rod to said first position after the release of said first contact means.

6. In the switch of claim 2, a projection operatively connected to said actuating means, said resilient member engaging said projection and being carried therewith to said second position.

7. The switch of claim 6, in which said actuating means is a rod and said projection is convexly formed on the periphery of said rod, said resilient member being positioned adjacent said convex projection, thereby to be carried by said projection during the movement of said rod from its first position to its second position.

8. The switch of claim 7, in which said resilient member comprises a spring substantially surrounding said rod, said spring being expanded over said convex projection upon the continued movement of said rod beyond said second position, thereby to be released from carrying engagement with said convex projection.

9. The switch of claim 1, in which said base member comprises a printed circuit board, and said second electrical contact is operatively connected to said board.

10. In the switch of claim 9, a housing operatively connected to said actuating means and to said circuit board, and a recess in said circuit board adapted to receive said actuating means as it moves toward and beyond said second position.

11. The switch of claim 1, in which a third electrical contact is fixed at the first position of said first electrical contact to be there engaged by said first electrical contact.

12. The switch of claim 2, in which said first electrical contact comprises a plate having an electrically conductive surface.

13. The switch of claim 12, in which said resilient member engages the surface opposite to said electrically conductive surface, and is carried with said plate when said plate is snapped out of engagement with said second contact means.

14. The switch of claim 1, in which said second contact means is operatively connected to said base member and projects outwardly therefrom thereby to provide a stop to prevent further movement of said first contact means beyond its second position of engagement with said second contact means.

15. The switch of claim 2, in which said base member comprises a printed circuit board, and said second electrical contact is operatively connected to said board.

16. In the switch of claim 15, a housing operatively connected to said actuating means and to said circuit board, and a recess in said circuit board adapted to receive said actuating means as it moves toward and beyond said second position.

17. The switch of claim 2, in which a third electrical contact is fixed at the first position of said first electrical contact to be there engaged by said first electrical contact.

18. The switch of claim 17, in which said first electrical contact comprises a plate having an electrically conductive surface.

19. The switch of claim 18, in which said resilient member engages the surface opposite to said electrically conductive surface, and is carried with said plate when said plate is snapped out of engagement with said second contact means.

20. The switch of claim 2, in which said second contact means is operatively connected to said base member and projects outwardly therefrom thereby to provide a stop to prevent further movement of said first contact means beyond its second position of engagement with said second contact means.

Claims

1. A snap-action electrical switch comprising a base member, actuating means operatively connected to said base member and movable from a first position to a second position, first electrical contact means operatively connected in holding engagement with said actuating means and movable therewith from a first to a second position, second electrical contact means at said second position of said first contact means and for receiving said first contact means in an electrical connection upon engagement therewith, means operatively connected to said actuating means and effective to release said first contact means from holding engagement with said actuating means when said first contact means engages said second contact means, and means to snap said first contact means out of engagement with said second contact means upon the release thereof from said actuating means.

2. The switch of claim 1, in which said release means comprises a resilient member operatively connected to said first contact means and resiliently engaging said actuating means, and means operatively connected to said actuating means and effective to flex said resilient member upon the engagement of said first contact means with said second contact means, thereby to release said resilient member from said actuating means for a period sufficient for said snap means to snap said first contact means out of engagement with said second contact means.

3. The switch of claim 2, in which said resilient member comprises a member having two parts and spring means operatively connected to said parts and effective to urge said parts into engagement with said actuating means and said flexing means comprises means for separating said parts from said actuating means upon the engagement of said first and second contact means.