US3621415A

US3621415A - Precision reed-type snap switches

Info

Publication number: US3621415A
Application number: US47221A
Authority: US
Inventors: Richard E Bell
Original assignee: AMF Inc
Current assignee: Siemens Electromechanical Components Inc
Priority date: 1970-06-18
Filing date: 1970-06-18
Publication date: 1971-11-16
Anticipated expiration: 1988-11-16
Also published as: CA919741A

Abstract

An improved precision-type snap switch with the same package and operating characteristics as a conventional precision-type snap switch, and having magnetically actuated reed switches providing sealed contacts.

Description

O United States Patent [111 3,621,415

[72] lnventor Richard E. Bell [56] R m-mm Cited mgemmlm UNITED STATES PATENTS [21] P 1 3,423,705 1/1969 Cherry etal. 300/67 F x [221 med a 310 762 3/1967 Goetz ass/20s x [45] Patemcd Nov. 16,1971 [73] Assignee AMF Incorporated Primary Examiner-Bemard A. Gilheany Assistant ExaminerR. N. Envall, Jr. Attorneys-George W. Price and Charles J. Worth [54] PRECISION REED-TYPE SNAP SWITCHES l 1 Claim, 9 Drawing Figs.

[52] US. Cl 335/205,

200/67 F, 335/206 ABSTRACT: An improved precision-type snap switch with [51] Im, Cl H0lh 5/18 the same package and operating characteristics as a conven- [50] Field of Search 335/205, tional precision-type snap switch, and having magnetically ac- IITIII W tuated reed switches providing sealed contacts.

I UI/// I My 29 PATENTEDHBV 18 ml 3. 621 A15 sum 1 of 2 PAmmsnunv 16 Ian 3,621 .415

INVENTOR RICHARD & BELL AGENT PRECISION REED-TYPE SNAP SWITCHES BACKGROUND AND SUMMARY OF THE INVENTION This invention relates generally to precision-type snap switches and more particularly to use of magnetically responsive reed switches in place of the conventional contact means thereof.

The packaging of precision-type snap switches has been generally standardized while these switches are substantially conventional single-pole, double-throw devices provided with normally closed (N.C.) and normally open (N.C.) contacts fixedly spaced from one another, and a common (C.) contact movable from one of the fixed contacts to the other to provide the switching function. The switches do also come in singlepole, single-throw configurations, either normally open or nonnally closed, thereby eliminating one of the fixed contacts.

Pushers or pushbuttons are provided to operate these switches which have biasing springs to exert a force to provide the snap action of the movable contacts and requisite contact pressure. The openings in the cases for the pushers form an entrance for contamination and humidity found in the surrounding atmosphere. The contacts of such switches are often subject to arcing conditions which are not retarded by normal atmosphere.

While reed switches have been embodied in mechanical switch means, the operating magnets thereof are normally moved axially along the reed switch thus requiring a greater throw than is available with a precision-type snap switch. Additionally, mechanical switch means with reed switches presently available are generally costly, difficult to manufacture and are not readily adjustable.

Accordingly, an object of the present invention is to provide magnetically responsive dry reed switches in a conventional precision-type snap switch package.

Another object of the present invention is to provide the foregoing switching means in which the required throw for the magnet approximates the normal throw of a conventional precision-type snap switch.

Still, another object of the present invention is to provide the foregoing switching means in which the contacts are submerged in a substantially inert atmosphere, and shielded from contamination and humidity.

And, another object of the present invention is to provide the foregoing switching means which can be manufactured and adjusted with relative facility.

And still, another object of the present invention is to provide the foregoing switching means which is more universally adaptable than conventional precision-type snap switches.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and advantages will appear more fully hereinafier from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein several embodiments of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only and are not to be construed as defining the limits of the invention.

FIG. 1 is a plan view of a switch, with the cover removed, made in accordance with the present invention;

FIG. 2 is a side elevational view of the unoperated switch of FIG. I, with portions thereof broken away to better illustrate the present invention;

FIG. 3 is a view similar to FIG. 2 with the switch thereof in the operated condition;

FIG. 4 is an enlarged sectional view through the S-spring of the switch of FIGS. 1 to 3 illustrating the magnet carrier loop of the S-spring and its interengagement with the switch actua- FIG. 5 is a plan view of a modified base for the switch of FIGS. 1 to 3;

FIG. 6 is a side elevational view of the modified base of FIG. Q, and a modified spring and magnet assembly in the unoperated position;

FIG. 7 is a sectional view taken on line 7-7 of FIG. 5 and including the modified spring and magnet assembly in the operated position; and

FIGS. 8 and 9 are enlarged side and front elevational views, respectively, of the modified spring and magnet assembly of FIGS. 6 and 7. DESCRIPTION OF THE INVENTION Referring now to the drawings and particularly to FIGS. 1 to 3, a precision-type snap switch means in accordance with the present invention is provided with a hollow cover 10 connected to a base 13 forming a conventional precision snap switch case. A pusher or pushbutton means 12 extends through the top wall of the cover 10 which defines a switch chamber 1 l.

The base 13 is provided with a common (C.) terminal 14 at one end while at its other end a normally closed (N.C.) terminal l5 and a normally open (N.C.) terminal 16 are provided. The base 13 also has an upwardly extending stop member 17 which preferably is axially aligned with the pusher 12.

An actuator arm or member 18 and a fixed arm or member 19 are disposed in spaced face-to-face axial alignment within the switch chamber 11, each being connected adjacent a different end of the base 13. The actuator 18 may be a rigid lever or, as shown, a spring arm connected to the base by the (C.) terminal 13. The faces at the spaced free ends of the

members

18 and 19 are suitably formed (see also FIG. 4) to provide seats for engaging and retaining the ends of an S-spring 20 which biases the actuator member 18 against the fully extended pusher 12 thereby assuming its normal or stable unoperated position, as shown in FIG. 2. When the pusher I2 is depressed to operate the switch means, the actuator member 18 is moved against the bias of the S-spring 20 into engagement with the stop I7 to its unstable operated position, as shown in FIG. 3. a

A pennanent magnet 21 is disposed in a suitable carrier 22 retained, in this instance, by the upper loop of the S-spring 20 adjacent the actuator member 18. Therefore, when the novel switch means is unoperated, the permanent magnet 21 is disposed adjacent the upper wall of the cover 10. When the pusher 12 is depressed to operate the novel switch means, the pennanent magnet 21 is moved to another position adjacent the base 13.

Precision-type snap switches commonly are single-pole, double-throw devices provided with nonnally closed (N.C.) and normally open (N.O.) contacts fixedly spaced from one another, and a common (C.) contact movable from one of the fixed contacts to the other. However, these switches do come in single-pole, single-throw configurations, either nonnally open or nonnally closed, thereby eliminating one of the fixed contacts.

The novel switch means of FIGS. 1 to 3 is provided with pair of conventional reed-

type switches

23 and 26, and will be described as being of a single-pole, double-throw configuration. The

reed switches

23 and 26 are of the type having a pair of open reed contacts sealed within elongated tubular envelope. The reeds are of a magnetic material and are provided with leads which extend outwardly through the ends of the envelope. It should be readily seen that the novel switch means could be of a single-pole, single-throw configuration by eliminating one of the

reed switches

23 or 26.

As best shown in FIG. I, reed switch 23, disposed on one side of the magnet 21, is provided with a lead 24 electrically connected to the (C.) temiinal l4 and a lead 25 connected to the (N.C.) terminal 15. The reed switch 26, disposed on the other side of the magnet 21, is similarly provided with a lead 27 electrically connected to the (C.) terminal 14 and a lead 28 connected to the (N.C.) terminal 16. The

switches

23 and 26, which are laterally spaced from one another, are also vertically spaced so that a different one of the switches is substantially coplanar with the magnet 21 when it is in its unoperated and operated positions. While the

leads

24 and 27 can be connected directly to the (C.) terminal 14, a bus bar or electrically conductive plate 29 is provided which also clamps the fixed end of the actuator member 18 to the base 13 to effect a better connection.

DESCRIPTION OF OPERATION 12 is depressed to operate the novel switch means, the magnet 21 moves away from the plane of reed switch 23 and to the plane of reed switch 26, as shown in FIG. 3. The reeds of the switch 23 open to electrically isolate the (NC) tenninal 15 from the (C.) terminal 14, and the magnet 21 causes the reeds of the switch 26 to close thereby electrically connecting the (C.) terminal I4 to the (NO) terminal 16. Upon release of the pusher 12, the bias of spring and the actuator member 18 if it is a leaf spring arm will return the novel switch means to its unoperated position.

DESCRIPTION OF MODIFICATIONS Referring now to FIGS. 5 to 7, the novel switch means may be provided with a modified base which is substantially the same as the base 13 except for a pair of laterally spaced pockets or

recesses

31 and 32. To correspond to the switch means of FIGS. 1 to 3, the reed switch 23 is disposed along the top of the base 30 above the pocket or recess 31, and the reed the magnet 21 and its carrier 22 would be disposed in the lower loop of the S-spring 20 adjacent the fixed arm or member 19.

However, a modified spring and magnet assembly, as also shown in FIGS. 8 and 9, may be provided in place of the spring 20, magnet 21 and carrier 22. This modified assembly is provided with a magnet 35, corresponding to the magnet 21, which is connected to the appropriate loop of the S-spring 20 by an epoxy or other suitable means. It should be readily understood that either spring-magnet assembly can be used interchangeably.

Although not shown, by changing the positions of the

switches

23 and 26, both switches could be normally open and closed simultaneously or sequentially, or be normally closed and open simultaneously or sequentially to make the novel switch means more universally adaptable than conventional precision snap switches.

Although several embodiments of the invention have been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will not be understood by those skilled in the art.

I claim:

I. A precision-type snap switch comprising a hollow cover defining a switch chamber;

a base connected to said cover, and having at least one terminal means at each of its ends which extends into said switch chamber and a fixed seat disposed between said terminal meansin said switch chamber; H W g H a pushbutton extending through said cover into said switch chamber and being movable on an axis substantially normail to said base;

an arm in said switch chamber connected at one end to said base and being free at its other end which is formed to provide a seat spaced from and movable relative to said fixed seat;

said arm being spring biased away from said base to an unoperated position engaging said pushbutton when fully extended and being movable toward said base to an operated position by said pushbutton;

' an S-shaped leaf spring engaged and retained at its ends by said seats;

a permanent magnet connected to and movable with said spring between two predetermined positions by movement of said arm;

at least one magnetically responsive reed switch disposed along one side of said switch chamber and having a pair of sealed reed contacts each with an exposed lead connected to a different one of said tenninal means; and

said reed switch being disposed in substantially the same plane as said permanent magnet in one of its predetermined positions, and being caused to open and close by movement of said permanent magnet.

2. The precision-type snap switch in accordance with claim I, wherein said permanent magnet is disposed in a tubular carrier retained in one of the loops of said S-shaped spring.

3. The precision-type snap switch in accordance with claim 1, wherein said permanent magnet is fixedly connected to the outer surface of one of the loops of said S-shaped spring.

4. The precision-type snap switch in accordance with claim 1, wherein said arm is made of an electrically conductive spring materi- 5. The precision-type snap switch in accordance with claim 1, and said base having at least one recess in communication with and forming part of said switch chamber; and

said reed switch being disposed in said recess.

6. The precision-type snap switch in accordance with claim 1, wherein said terminal means at one end of said base being a common terminal means;

said base having a pair of terminal means at its end opposite from said common terminal means;

a pair of magnetically responsive reed switches each disposed along the side of the switch chamber opposite from the other and having a pair of scaled reed contacts each with an exposed lead;

one of said leads of said pair of reed switches being connected to said common terminal means and the other of said leads of each of said pair of reed switches being connected to a different one of said pair of terminal means; and

each of said reed switches being disposed in substantially the same plane as permanent magnet in one of its predetennined positions.

7. The precision-type snap switch in accordance with claim 6, and

each of said reed switches being disposed in a plane different from the plane of the other of said reed switches.

8. The precision-type snap switch in accordance with claim 7, and

said base having at least one recess in communication with and forming part of said switch chamber; and

one of said reed switches being disposed in said recess.

9. The precision-type snap switch in accordance with claim 6, and

said pair of reed switches being disposed in substantially the same plane.

10. The precision-type snap switch in accordance with claim 9, and M m u 7 H 1 said base having a pair of recesses in communication with and forming parts of said switch chamber; and said reed switches each being disposed in a different one of said recesses.

11. The precision-type snap switch in accordance with claim 6, and

said arm being of an electrically conductive spring material;

and

a plate member connecting said leads to said common terminal means and overlying and clamping the connected end of said am at said base.

i i i i

Claims

1. A precision-type snap switch comprising a hollow cover defining a switch chamber; a base connected to said cover, and having at least one terminal means at each of its ends which extends into said switch chamber and a fixed seat disposed between said terminal means in said switch chamber; a pushbutton extending through said cover into said switch chambeR and being movable on an axis substantially normal to said base; an arm in said switch chamber connected at one end to said base and being free at its other end which is formed to provide a seat spaced from and movable relative to said fixed seat; said arm being spring biased away from said base to an unoperated position engaging said pushbutton when fully extended and being movable toward said base to an operated position by said pushbutton; an S-shaped leaf spring engaged and retained at its ends by said seats; a permanent magnet connected to and movable with said spring between two predetermined positions by movement of said arm; at least one magnetically responsive reed switch disposed along one side of said switch chamber and having a pair of sealed reed contacts each with an exposed lead connected to a different one of said terminal means; and said reed switch being disposed in substantially the same plane as said permanent magnet in one of its predetermined positions, and being caused to open and close by movement of said permanent magnet.

2. The precision-type snap switch in accordance with claim 1, wherein said permanent magnet is disposed in a tubular carrier retained in one of the loops of said S-shaped spring.

4. The precision-type snap switch in accordance with claim 1, wherein said arm is made of an electrically conductive spring material.

5. The precision-type snap switch in accordance with claim 1, and said base having at least one recess in communication with and forming part of said switch chamber; and said reed switch being disposed in said recess.

6. The precision-type snap switch in accordance with claim 1, wherein said terminal means at one end of said base being a common terminal means; said base having a pair of terminal means at its end opposite from said common terminal means; a pair of magnetically responsive reed switches each disposed along the side of the switch chamber opposite from the other and having a pair of sealed reed contacts each with an exposed lead; one of said leads of said pair of reed switches being connected to said common terminal means and the other of said leads of each of said pair of reed switches being connected to a different one of said pair of terminal means; and each of said reed switches being disposed in substantially the same plane as permanent magnet in one of its predetermined positions.

7. The precision-type snap switch in accordance with claim 6, and each of said reed switches being disposed in a plane different from the plane of the other of said reed switches.

8. The precision-type snap switch in accordance with claim 7, and said base having at least one recess in communication with and forming part of said switch chamber; and one of said reed switches being disposed in said recess.

9. The precision-type snap switch in accordance with claim 6, and said pair of reed switches being disposed in substantially the same plane.

10. The precision-type snap switch in accordance with claim 9, and said base having a pair of recesses in communication with and forming parts of said switch chamber; and said reed switches each being disposed in a different one of said recesses.

11. The precision-type snap switch in accordance with claim 6, and said arm being of an electrically conductive spring material; and a plate member connecting said leads to said common terminal means and overlying and clamping the connected end of said arm against said base.