US3510614A - Single pole snap acting switch - Google Patents

Description

y 5, 1970 R. H. KIESSLING 3,510,614

smema POLE SNAP ACTING swncn Filed Feb. 26, 1968 INVENTOR. RUDOLF H. KIESSLING United States Patent 3,510,614 SINGLE POLE SNAP ACTING SWITCH Rudolf H. Kiessling, Milwaukee, Wis., assignor to Square D Company, Park Ridge, 11]., a corporation of Michigan Filed Feb. 26, 1968, Ser. No. 708,295 Int. Cl. H01h 13/36 U.S. Cl. 20067 4 Claims ABSTRACT OF THE DISCLOSURE An inexpensive single pole snap acting switch having a zig-zagged shaped member to provide a pair of oppositely facing zigs and a common terminal for the switch with the zigs each providing a pair of spaced pivots for an actuator and a movable contact blade for the switch.

This invention relates to a snap switch and more particularly, to a snap switch of the single pole type.

Snap action switches are well known and the available in a large variety of shapes and sizes, depending upon the switching function they are required to satisfy. In many applications snap switches are operated by other mechanisms. For example, as illustrated in U.S. Pat. No. 3,258,566, which issued to Don I. Arneberg et al. on June 28, 1966, a separately enclosed snap switch is positioned Within a cavity in the housing of an excess current responsive mechanism. While the switch as disclosed in the Arneberg et a1. patent has provided reliable service, the number and complexity of its components resulted in a switch having a high manufacturing cost and while the switch mechanism according to the present invention may be used in other applications, as will be readily apparent, it is particularly suited to replace the snap switch in the Arneberg et al. patent.

It is an object of the present invention to provide a single pole snap acting switch that is economical to manufacture and which will provide a high degree of reliability in its switching operations.

Another object is to provide the switching mechanism for a single pole snap acting type switch with a member that is zig-Zag shaped and functions to provide a common terminal for the switch as well as pivot supports for both the switch actuator and the movable contact support for the switch.

Another object is to provide the switching mechanism for a single pole snap acting type switch with a zig-zag shaped member Which functions to provide a commor terminal for the switch and pivotal supports for an actuator and a movable contact blade and to form the blade of resilient material and to pivotally support the blade on the member at two spaced positions so portions of the blade 'will engage a plurality of contact areas on a stationary contact to assure electrical reliability of the switch when the blade moves into engagement with the stationary contact with a snap action in response to the movements of the actuator.

A further object is to provide a single pole snap switch with a member that has a zig-zag shape to provide a terminal portion at one end of the member and a support for positioning the other end of the member within a cavity of a housing for the switch and to locate a pair of oppositely facing zigs between the ends of the member so that one of the zigs provides a pivot support for an actuator for the switch and the other of the zigs provides a pivot support for a movable resilient blade that is connected to a portion of the actuator by a spring sothe blade moves with a snap action about its pivot in rseponse to movements of the actuator.

Further objects and features of the invention will be 3,510,614 Patented May 5, 1970 readily apparent to those skilled in the art from the specification and appended drawing illustrating certain preferred embodiments in which:

FIG. 1 is a front elevational view of a switch embodying the principles of the present invention.

FIG. 2 is a cross sectional view taken along line 22 in FIG. 1.

FIG. 3 is an exploded view showing in perspective certain of the parts of the switch in FIG. 1.

Referring to the drawing, a switch 10 is provided with an outer housing 12 that is shaped and sized to be received within a recess in a housing for a current responsive device, not shown, as disclosed in the Arneberg et al. patent supra. The housing 12 provides a support for wire connecting terminals designated as 14, 16 and 18, each of which is disposed external of the housing 12 and includes a threaded fastener and a wire clamping member, as are conventionally known. The housing 12 includes a projection 20 and an opening which receives a screw 22 for mounting the switch 10 in the device and is formed of two housing parts 12a and 12b which are suitably secured together to enclose an internal cavity 24.

As most cleanly shown in FIGS. 2 and 3, the switch 10 includes a pair of stationary contact assemblies 26 and 28, a movable contact blade 30, a pivotal switch actuator 32, a member 34 having a zig-zag shape and a spring 36. The zig-zag shaped member 34 which acts as a common terminal member and provides pivot supports for the blade 30 and the actuator 32, has a pair of opposite end portions 38 and 40. The end 38 extends through a slot 42 in the housing 12 and provides a portion 44 of the wire connecting terminal 14 and positions the end portion 38 in the cavity 24. The end 40, which is received in a slot 46 in a side wall portion of the housing 12, positions the end 40 in the cavity 24. The shape of the member 34 between the ends 38 and 40 is formed as a zig-zag in that it includes a series of short sharp angles to provide a pair of oppositely facing zigs 48 and 50 between the ends 38 and 40. The zigs 48 and 50 are provided by the angles that contribute to the zig-zag shape of the member 34. The zig 48, which is disposed adjacent the end 40 and faces toward a bottom wall 52 of the cavity 24 provides a pivot for the actuator 32. Similarly, the zig 50 is located between the zig 48 and the end 38 is formed to face upwardly in the cavity 24 and provides a pivot for the blade 30. The member 34 also includes a notch 54 extending from the end 40 through the portions of the member 34 providing the zigs 48 and 50. The notch 54- provides the member 34 with a pair of spaced parallel zig-zag shaped arms 56 and 58 so that each of the zigs 48 and 50 has a pair of spaced pivots as defined by the apexes of the angles forming the zigs 48 and 50. A portion of the apexes of each of the zigs 48 and 50 in each of the arms 56 and 58 is indented, as indicated by numeral 60. The indentations 60 serve to position the actuator 32 and the blade 30 on the member 34.

The actuator 32 is formed of relatively rigid material to have a central body portion 62, a curved upper portion 64 and an angled lower portion 68. The central body portion extends through the notch 54 and the curved portion 64, at an upper end of the central portion 62, extends through an opening 66 in the housing 12 to the exterior of the housing 12. The angled portion 68 ex tends from a lower end of the body portion 62 into the portion of the cavity 24 below the member 34. Extending outwardly along the marginal edges of the body portion 6-2 are a pair of spaced parallel arms 70 each presenting a pointed edge 72 at its free end. The pointed edges 72 are each received in one of the indentations 60 in the arms 56 and 58 providing the zig 48 to position the arms 70 on the zig 48 so the actuator 32 may be pivotally rotated about the zig 48.

The blade 30 is formed of a relatively thin strip of flat flexible material to have a pair of spaced arms 74 extending from a body portion 76. The arms 74 have free ends 78 which are positioned in the indentations 60 in the arms 56 and 58 providing the zig 50. The body portion 76 and the angled portion 68 have openings 80 and 82 which receive the opposite ends of the torsion spring 36. The spring 36 extends through the notch 54 and constantly urges the free ends 78 into the indentations of zig 50 and the edges 72 into the indentations 60 of the Zig 48.

The stationary contact assemblies 26 and 28 have ends extending through suitable slots in the walls of the housing 12 to provide wire connecting terminal portions 84 and 86 external of the housing 12 which cooperate with suitable wire clamps and screws to receive a bared end of a wire conductor as is well known. Additionally, the stationary contact assemblies 26 and 2-8 each includes a stationary contact supporting portion respectively designated as 88 and 90 which are spaced on opposite sides of the body portion 76 of the contact blade 30. The portions 88 and 90 each have extending tongues 92 received in suitable notches in the housing 12 to position the portions 88 and 90 on opposite sides of the contact blade 30. As shown in FIG. 3, each of the portions 88 and 90 is provided with three spaced openings 94 wherein one or more rivets 96 of a suitable contact material may be secured so that the heated portions of the rivets 96 face the contact blade 30. Thus if only a single contact surface is required on the stationary contact assemblies 26 and 28, a single rivet 96 is secured in the central opening 94 in each contact supporting portion 88 and 90. When the switch ,10 is required to have a greater contact reliability, a pair of rivets 96 are secured in each of the end holes 94 in the body portions 88 and 90 to face the body portion 76 of the contact blade 30 and provide each stationary contact assembly 26 and 28 with a pair of raised contact surfaces. As stated, the contact blade 30 is formed of flexible material. Thus when the contact blade 30 engages the raised contact surfaces on either stationary contact assembly 26 or 28, the blade 30 will flex and engage both raised contact surfaces and provide a dual electrical path between the blade and the pair of raised stationary contact surfaces. Obviously, if desired, the spaced stationary contact surfaces on the portions 88 and 90 may be achieved without the use of rivets. For example, by forming suitable integral projections in the portions 88 and 90 or overlays of well known contact materials on the portions 88 and 90.

When the switch is installed in a device as disclosed in the Arneberg et a1. patent, the terminal 14 is common to the circuits connected with the terminals 16 and 18, e.g., the terminal 18 may be connected in a circuit with a coil of an electromagnetic device and the terminal 16 in a circuit with an alarm device. When the switch 10 is deactivated, the actuator 32 and the movable contact blade are positioned as in FIG. 2, with the body portion 76 of the blade 30 biased by the spring 36 to engage the pair of spaced contact surfaces on the contact assembly 26 to thereby activate an alarm circuit. When the parts of the switch 10 are positioned as in FIG. 2, a dual circuit from the terminal 14 through the pair of pivoted hinge points provided by the pair of arms 74 and the pair of indentations 60 in the arms 56 and 58 as well as the circuit between the member 30 and the pair of spaced contact surfaces on the stationary contact assembly 28 will be completed to provide the switch 10 with a high degree of electrical reliability. Additionally, when the switch 10 is in the condition shown in FIG. 2, the actuator 32 will have a portion engaging a stop surface 96 on the housing 12 to precisely locate the position of a curved actuating surface 98 on the curved portion 64. Also, if an alarm circuit is not required, the stationary contact assembly may be omitted, permitting the contact blade 30 to engage a stop surface 100 on the housing 12.

The switch 10 is actuated when a suitable force applied to the actuating surface 98 causes the actuator 32. to rotate in a clockwise direction about the pivot provided by the zig 50. During clockwise movement of the actuator 32, the end of the spring 36 secured in the opening 82 passes through a center line through the opening 80 and the zig and provides a force which causes the blade 30 to rotate with a snap action movement about the pivot provided by the zig 50 to a position wherein the body portion 76 engages the pair of raised contact surfaces on the stationary contact assembly 28 and complete an electric circuit between the common terminal 14 and the terminal 16. The movement of the actuator 32 in a clockwise direction, subsequent to the movement of the blade 30, ceases when a portion of the actuator 32 engages a stop surface 102 on the housing 12 after the curved portion 64 is received in a recess 104 in the housing 12. When the body portion 76 is in engagement with the pair of raised contact surfaces on the stationary contact assembly 28, the blade 30 will provide a dual circuit between the member 32 and the stationary contact assembly 28.

When the manual operating force on the actuator 32 is released the actuator will move in a counterclockwise direction about the pivot provided by the zig 50 to the position shown in FIG. 2. During the counterclockwise movement of the actuator 32, the blade 30 will move with a snap toggle spring action to the position shown in FIG. 2 and there will be maintained by the force supplied by the spring 36.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. A snap acting switch comprising: a hollow housing, a zig-zag shaped member having a pair of spaced ends, a pair of opositely facing spaced zigs disposed between the ends and a notch extending through the pair of zigs providing a pair of spaced parallel zig-zag shaped arms with each of the zigs providing a pair of spaced pivots in the parallel arms, one of said ends extending external of the housing and providing a terminal portion for the switch and the other of said pair of ends providing a portion for mounting the said other end of the member in the housing, an indentation in each of the zigs in each of the arms of the member, an actuator having a central portion, a pair of end portions extending from opposite ends of the central portion with one of said end portions extending through the notch and projecting from a first side of the member to present a surface that is external of the housing, a pair of spaced arms extending from marginal edges of the central portion presenting free pointed ends that are received in the indentations in a first one of said pair of zigs and spacing the central portion from the spaced pivots provided by the said one pair of zigs, a second of said pair of end portions extending at an angle from the central portion to provide a free end that is spaced from a side of the member that is opposite the first side, a movable contact blade having a pair of spaced legs extending from a contact portion, a free end on each of legs received in the indentations in a second one of said pair of legs for pivotally mounting the blade on the first side of the member, and a tensiontype spring extending through the notch and having opposite ends respectively connected to the second end portion of the actuator and the contact portion of the blade for forcing the pointed edges on the actuator and free ends on the blade respectively into pivotal contact with the indentations in the first and the second pairs of zigs and for causing the blade to move with a snap action about the spaced pivots provided by the second zig in response to a pivotal movement of the actuator about the spaced pivots provided by the first zig.

2. The snap switch in accordance with claim 1 including a stationary contact structure having a terminal portion disposed external of the housing and a contact portion positioned in the housing to be engaged by portions of the contact blade and wherein the contact portion of the stationary contact includes a pair of spaced contact surfaces which are bridged by portions of the blade when the blade engages the contact portion.

3. The snap switch in accordance with claim 1 including a pair of spaced stationary contact structures spaced on opposite sides of the contact blade and each of said stationary contact structures having a terminal portion disposed external of the housing and a contact portion positioned in the housing to be engaged by portions of the contact blade and wherein the contact portion of the stationary contact includes a pair of spaced contact surfaces which are bridged by portions of the blade when the blade engages the contact portion.

4. The snap switch in accordance with claim 2 wherein the contact blade is formed of flexible material and contact portion of the blade provides an anchor for one end of the spring and the free end on the second end portion of the actuator has an opening therein providing an anchor for the other end of the spring.

References Cited UNITED STATES PATENTS ROBERT K. SCHAEFER, Primary Examiner 20 D. SMITH, JR., Assistant Examiner

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