Rocker switch

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improvement in a rocker switch that is used in various kinds of OA (office automation) machines or equipments, amusement and game machines, measurement instruments, medical instruments and the like.

2. Description of the Related Art

A rocker switch (also called a seesaw switch due to its mechanism) is used, for example, as a power switch in various kinds of OA machines, amusement and game machines, measurement instruments, medical instruments and the like. In general, the rocker switch is constructed such that its switch components or parts are housed in a square or rectangular box (casing) the top of which is open and an operation button (operation knob) is mounted at the opening space of the box at the top thereof such that it can be moved for seesaw movement.

Various types of rocker switches having their constructions or structures different from one another have been heretofore proposed, and the present invention relates to an improvement in a rocker switch of the type in which a movable contact piece is made of an elastic or resilient member and is mounted on a movable contact piece support member such that it can move for swinging or rocking movement; a terminal portion (tab terminal) of the movable contact piece support member is led out to the outside of a box through a corresponding slit formed through the bottom wall of the box; a terminal portion (tab terminal) of a fixed contact piece is led out to the outside of the box through a corresponding slit formed through the bottom wall of the box; an actuator for actuating the movable contact piece is integrally formed on an operation button or knob and extends downwardly therefrom; and when the operation button is operated for rocking operation, the movable contact piece actuator is moved for rocking operation together with the operation button thereby to actuate the movable contact piece so that it is moved to one position where a movable contact mounted thereto is brought into contact with a fixed contact mounted to the fixed contact piece or the other position where the movable contact is spaced apart from the fixed contact.

Rocker switches of this type have been also proposed in the past, and a seesaw switch is disclosed in, for example, Japanese Examined Utility Model Application Publication No. 05-001870 (JP, 05-001870, Y(1993)) published on Jan. 19, 1993, in which a large contact pressure can be applied between a movable contact and a fixed contact. In Japanese Examined Utility Model Application Publication No. 06-035333 (JP, 06-035333, Y(1994)) published on Sep. 14, 1994, there is disclosed a terminal fixing structure for a seesaw switch in which there are no possibility that a bad or poor contact or a joining between contacts by fusion occurs. In Japanese Unexamined Patent Application Publication No. 08-055542 (JP, 08-055542, A(1996)) published on Feb. 27, 1996, there is disclosed a seesaw switch in which if a movable contact and a fixed contact should be joined with each other by fusion, it is ensured that these contacts can be securely opened or released from each other, but a compression coil spring is used as a movable contact actuator. In Japanese Unexamined Patent Application Publication No. 2001-195955 (JP, 2001-195955, A) published on Jul. 19, 2001, a seesaw switch having a dustproof structure is disclosed, but a compression coil spring is used as a movable contact actuator. In Japanese Patent No. 3224949 (JP, 3224949, B) issued on Nov. 5, 2001, there is disclosed a terminal fixing structure of a seesaw switch using a clinching or fastening technique in which a displacement in position of a terminal and/or a displacement in position of a contact is hard to occur when a terminal is fixed by use of a clinching or fastening technique, but a combination or assembly of a torsion coil spring and a movable contact piece is used.

The prior art rocker switches disclosed in the above-stated documents have disadvantages that it is not easy to build or assemble a terminal portion of a movable contact piece support member and a terminal portion of a fixed contact piece in a box and to fix them thereto, and that there sometimes occurs a case that the terminal portion or portions of the movable contact piece support member and/or of the fixed contact piece are securely not fixed to the box. Moreover, there is a drawback that when an operation button is operated, there cannot be obtained actual feeling that the operation button swings lightly and smoothly (without feeling a resistance thereto) as well as that the operation button has positively stopped at its on position or off position, that is, feeling in actuation of the operation button is bad or unfavorable.

In addition, there is a problem in that a movable contact piece is rapidly swung, and since a stable reverse operation thereof cannot be obtained, it is difficult to reduce a bounce time in throwing the movable contact piece to its on position. Furthermore, it is also difficult to make smaller an arc that occurs when the movable contact piece is thrown to its off position.

It is necessary to prevent a trouble or accident that a displacement in position of a movable contact piece occurs or a movable contact piece gets out of place due to an external shock from occurring. However, in the prior art rocker switches disclosed in the above-stated documents, there is not provided means for preventing such trouble or accident from occurring without fail.

Moreover, since it is impossible to prevent an arc that occurs between a movable contact piece and a movable contact piece support member due to a bounce of the movable contact piece in turning a rocker switch on or off, there is a defect that a lifetime of the switch is shortened.

Further, TAB 187 terminal of IEC (International Electrotechnical Commission) standard is used as a terminal portion (tab terminal) of a rocker switch of rated current 10A type, and it is necessary that TAB 250 terminal of IEC standard is used as a terminal portion (tab terminal) of a rocker switch of rated current 16A type. The width of TAB 187 terminal is 4.75 mm, while the width of TAB 250 terminal is 6.35 mm. Therefore, the width of TAB 250 terminal is wider by 1.6 mm than that of TAB 187 terminal. For example, in some machine or apparatus having a rocker switch of rated current 10A type mounted thereon, if the user therefor wishes to use a rocker switch of rated current 16A type in place of the rocker switch of rated current 10A type, the machine or apparatus must have a space in which the rocker switch of rated current 16A type can be accommodated at a location that the rocker switch of rated current 10A type has been now mounted, because the external sizes (width and depth) of a box of the rocker switch of rated current 16A type are necessarily larger than those of a box of the rocker switch of rated current 10A type. If the machine or apparatus should not have a space in which a rocker switch having its external width and depth larger than those of the rocker switch of rated current 10A type can be accommodated, it is impossible to use the rocker switch of rated current 16A type in that machine or apparatus.

In recent years, various kinds of OA machines or equipments, amusement and game machines, measurement instruments, medical instruments and the like are showing a tendency to be miniaturized more and more, and hence there is a strong demand for the advent of a miniature rocker switch that has larger rated current/voltage value as well as can be accommodated in a small space.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a rocker switch in which components thereof can easily be built or assembled in a box and fixed thereto, and yet, a rapid reverse operation as well as favorable and excellent feeling in actuation of an operation button when it is operated, can be obtained.

Another object of the present invention is to provide a rocker switch in which favorable and excellent feeling in actuation of an operation button when it is operated, can be obtained, and yet, there occurs no trouble or accident that a displacement in position of a movable contact piece occurs or a movable contact piece gets out of place due to an external shock.

Another object of the present invention is to provide a rocker switch in which favorable and excellent feeling in actuation of an operation button when it is operated, can be obtained, and yet, no arc occurs at all between a movable contact piece and a movable contact piece support member due to a bounce of the movable contact piece.

Still another object of the present invention is to provide a rocker switch of a predetermined rated current/voltage that can be used as another rocker switch of rated current/voltage larger than the predetermined rated current/voltage without increasing the external sizes thereof.

In order to accomplish the foregoing objects, in one aspect of the present invention, there is provided a rocker switch comprising: a movable contact piece having a generally U-like shape, that is made of an elastic member; a movable contact that is mounted on a portion of the movable contact piece near one end thereof; a movable contact piece support member that comprises: a movable contact piece support for swingably supporting the movable contact piece; and a tab terminal hanging down from the movable contact piece support; a pair of detents that is formed to project on the both side edges of the tab terminal of the movable contact piece support member in the direction of the width of the tab terminal at predetermined positions thereof; a fixed contact piece that comprises: a fixed contact support on which a fixed contact is mounted; and a tab terminal hanging down from the fixed contact support; a pair of detents that is formed to project on the both side edges of the tab terminal of the fixed contact piece in the direction of the width of the tab terminal at predetermined positions thereof; a box that has its top opened and a slit formed through the bottom wall of the box, through which the tab terminal of the movable contact piece support member is pulled out toward the outside and a slit formed through the bottom wall of the box, through which the tab terminal of the fixed contact piece is pulled out toward the outside; an operation button that comprises a movable contact piece actuator to be engaged with the movable contact piece and is swingably mounted to the opening portion of the box; and a recess that is formed on a portion of the movable contact piece near the other end thereof to extend in the direction of the width of the movable contact piece and has a generally circular arc-shape in section engaged with a generally circular arc-shaped tip in section of the movable contact piece actuator of the operation button, and wherein the movable contact piece support member is engaged and secured on the bottom wall of the box by forcedly bending a pair of the detent pieces of the tab terminal thereof outwardly in the direction of the width thereof and engaging them, the tab terminal being pulled out toward the outside through the corresponding slit formed through the bottom wall of the box; the fixed contact piece is engaged and secured on the bottom wall of the box by forcedly bending a pair of the detent pieces of the tab terminal thereof outwardly in the direction of the width thereof and engaging them, the tab terminal being pulled out toward the outside through the corresponding slit formed through the bottom wall of the box; the operation button is swingably mounted to the opening portion of the box in the state that the generally circular arc-shaped tip in section of the movable contact piece actuator is engaged with the recess of a generally circular arc-shape in section of the movable contact piece; and the movable contact piece actuator that is swingable with the swinging movement of the operation button causes the movable contact piece to be swung to the switch-on position where the movable contact thereof comes into contact with the fixed contact or the switch-off position where the movable contact thereof is away from the fixed contact.

In a first preferred embodiment, the operation button further includes a rod-like member projecting beyond the tip of the movable contact piece actuator. The movable contact piece has an elongate aperture at a portion thereof near the recess, into which the forward end of the rod-like member of the operation button is inserted with a clearance or play therebetween. The forward end of the rod-like member is inserted into the elongate aperture with a clearance or play therebetween when the operation button is swingably mounted to the opening portion of the box.

In a second preferred embodiment, the box has a generally rectangular or square shape in plan, and a partition wall that isolates the tab terminal of the movable contact piece support member and the tab terminal of the fixed contact piece from each other, is formed on the bottom surface of the bottom wall of the box. The length of the partition wall is set to be substantially equal to those of the tab terminals, and the slits are formed obliquely in the bottom wall of the box from the vicinities of the corners thereof to form a predetermined angle with one side of the bottom wall respectively.

In a third preferred embodiment, the rocker switch further includes a conductive resilient piece that is swingably mounted on the movable contact piece support member. The conductive resilient piece is located, when the movable contact piece is swingably mounted on the movable contact piece support member, between the movable contact piece and the movable contact piece support member and is in electrically contact with both the movable contact piece support member and the movable contact piece.

The conductive resilient piece comprises: a sheet-like resilient piece body; a pair of opposed retentive pieces that substantially stand erect from the resilient piece body; and at least one pair of opposed protrusions that project outwardly and upwardly from the resilient piece body in the direction of forming generally right angles with a line connecting the retentive pieces. A pair of the retentive pieces is pressed and abutted against the movable contact piece support member when the movable contact piece is swingably mounted on the movable contact piece support member, and at least one pair of the protrusions is pressed and abutted against the movable contact piece when the movable contact piece is swingably mounted on the movable contact piece support member through the resilient piece therebetween.

With the construction described above, it is possible to mount or assemble the fixed contact piece and the movable contact piece support member in the box and to secure them simply and easily with accuracy and stability. In addition, engagement between each movable contact piece actuator of the operation button and the movable contact piece is in the rolling friction state. As a result, there can be obtained actual feeling that the operation button swings lightly and smoothly as well as that the operation button has positively stopped at its switch-on position or switch-off position, and feeling in actuation of the operation button comes to much favorable or excellent. Furthermore, the quick swinging operation of the movable contact piece is made possible and the more stable reverse operation of the movable contact pieces is obtained. Accordingly, a bounce time in throwing the movable contact piece to its switch-on position can be much more reduced and an arc occurring in throwing the movable contact piece to its switch-off position can also be made smaller. As a result, wear and tear of the contacts are further restrained and there can be provided the contacts the lifetime of which is much more longer.

In addition, in accordance with the first embodiment, since the rod-like member of the movable contact piece actuator of the operation button is inserted into the elongate aperture of the movable contact pieces with a clearance between the rod-like member and the periphery of the elongate aperture, it is ensured that there occurs no trouble or accident that a displacement in position of the movable contact piece occurs or the movable contact piece falls off due to an external shock, and hence it is possible to make the operation of the rocker switch stable.

In accordance with the second embodiment, since a rocker switch of a predetermined rated current/voltage can be used as another rocker switch of rated current/voltage larger than the predetermined rated current/voltage without increasing the external sizes of the box, OA machines or equipments, amusement and game machines, measurement instruments, medical instruments and the like, for example, can be modified to ones each having larger rated current/voltage value without increasing sizes thereof.

In accordance with the third embodiment, since no arc occurs between the movable contact piece and the movable contact piece support piece due to a bounce occurring on turning the rocker switch on or off, a lifetime of these components are greatly lengthened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a plan view showing an operation button used in a first embodiment of the rocker switch according to the present invention.

FIG. 2

is a side view of

FIG. 1

as viewed from below.

FIG. 3

is a right-hand side view of FIG.

1

.

FIG. 4

is a bottom view of FIG.

1

.

FIG. 5

is a sectional view taken along the line

5

—

5

in FIG.

1

and looking in the direction indicated by the arrows.

FIG. 6

is a plan view showing a box used in a first embodiment of the rocker switch according to the present invention.

FIG. 7

is a side view of

FIG. 6

as viewed from below.

FIG. 8

is a right-hand side view of FIG.

6

.

FIG. 9

is a bottom view of FIG.

6

.

FIG. 10

is a sectional view taken along the line

10

—

10

in FIG.

6

and looking in the direction indicated by the arrows.

FIG. 11

is a sectional view taken along the line

11

—

11

in FIG.

6

and looking in the direction indicated by the arrows.

FIG. 12

is a sectional view taken along the line

12

—

12

in FIG.

6

and looking in the direction indicated by the arrows.

FIG. 13

is a plan view showing a movable contact piece used in a first embodiment of the rocker switch according to the present invention.

FIG. 14

is a side view of

FIG. 13

as viewed from below.

FIG. 15

is a bottom view of FIG.

13

.

FIG. 16

is a plan view showing a movable contact piece support member used in a first embodiment of the rocker switch according to the present invention.

FIG. 17

is a side view of

FIG. 16

as viewed from below.

FIG. 18

is a right-hand side view of FIG.

16

.

FIG. 19

is a plan view showing a fixed contact piece used in a first embodiment of the rocker switch according to the present invention.

FIG. 20

is a side view of

FIG. 19

as viewed from below.

FIG. 21

is a right-hand side view of FIG.

19

.

FIG. 22

is a generally sectional view showing the switch-off state of a first embodiment of the rocker switch according to the present invention.

FIG. 23

is a generally sectional view showing the switch-on state of a first embodiment of the rocker switch according to the present invention.

FIG. 24

is a generally sectional view showing the switch-on state of a second embodiment of the rocker switch according to the present invention.

FIG. 25

is a bottom view of a box used in a second embodiment of the rocker switch according to the present invention.

FIG. 26

is a plan view showing the state that two fixed contact pieces and two movable contact piece support members have been mounted in the box shown in FIG.

25

.

FIG. 27

is a plan view showing a conductive resilient piece used in a third embodiment of the rocker switch according to the present invention.

FIG. 28

is a left-hand side view of FIG.

27

.

FIG. 29

is a side view of

FIG. 27

as viewed from below.

FIG. 30

is a generally perspective view showing the state that the resilient piece shown in

FIGS. 27-29

has been mounted on a movable contact piece support of the movable contact piece support member used in a second embodiment.

FIG. 31

is a plan view showing the state that the resilient piece shown in

FIGS. 27-29

has been mounted on one of the two movable contact piece support members shown in FIG.

26

and on the other of the two movable contact piece support members has been mounted both the resilient piece and the movable contact piece.

FIG. 32

is a generally sectional view showing the switch-on state of a third embodiment of the rocker switch according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth hereinafter; rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

At first, there will be described a first embodiment of the rocker switch according to the present invention in detail with reference to

FIGS. 1

to

23

.

FIGS. 1-5

show an operation button (operation knob) used in the first embodiment of the rocker switch, and

FIG. 1

is a plan view of the operation button,

FIG. 2

is a side view of

FIG. 1

as viewed from below,

FIG. 3

is a right-hand side view of

FIG. 1

,

FIG. 4

is a bottom view of

FIG. 1

, and

FIG. 5

is a sectional view taken along the line

5

—

5

in FIG.

1

and looking in the direction indicated by the arrows. The operation button

1

comprises: a top wall

1

A having a generally rectangular shape in plan as shown in

FIG. 1

; a pair of side walls (hereinafter, each referred to as minor side wall)

1

B,

1

B hanging down obliquely from opposed edges of minor sides of the top wall

1

A, respectively, as shown

FIGS. 2

,

4

and

5

; and a pair of side walls (hereinafter, each referred to as major side wall)

1

C,

1

C hanging down substantially vertically from opposed edges of major sides of the top wall

1

A, respectively, as shown

FIGS. 2 and 4

. As is apparent from

FIGS. 2 and 5

, the top wall

1

A is formed in a concave in its longitudinal direction, and each major side wall

1

C has its wall surface of a generally isosceles trapezoid as is clear from FIG.

2

. Each minor side wall

1

B has its wall surface of a generally rectangle as is clear from FIG.

3

.

On each of the major side walls

1

C at the central portion in longitudinal direction thereof near the bottom side is formed a rotatable shaft

11

projecting outwardly from the major side wall

1

C at substantially right angles therewith. The rotatable shafts

11

on both the major side walls

1

C are aligned with each other. As is clear from

FIGS. 4 and 5

, a pair of rectangular pillar-shaped movable contact piece actuators

12

,

12

each having a generally rectangular shape in cross section are formed integrally with the underneath surface of the top wall

1

A and with the corresponding one of the major side walls

1

B. These movable contact piece actuators

12

are formed, in this embodiment, along a straight line connecting between the rotatable shafts

11

, and portions of the movable contact piece actuators

12

that hang down from the bottom of the operation button

1

are tapered in their major-side walls opposed to each other, as is apparent from

FIGS. 2

,

3

and

5

. In addition, the tip

123

of each of the movable contact piece actuators

12

are formed to have a generally circular arc shape, as is clear from

FIGS. 2 and 5

.

On the underneath surface of the top wall

1

A is formed integrally therewith a plate-like wall

13

that hangs down from its central portion in the longitudinal direction thereof. This wall

13

is formed between the opposed side surfaces of the movable contact piece actuators

12

that are joined and united through the wall

13

. As is apparent from

FIGS. 3 and 5

, the wall

13

projects downwardly by a predetermined distance from the bottom of the operation button

1

, and the forward end portion

131

thereof is shortened in a part thereof opposite to a partition wall

21

of a box

2

(see

FIGS. 6-12

) described later so that the forward end portion

131

cannot come into contact with the top of the partition wall.

As is clear from

FIGS. 3-5

, a rod

124

formed into a generally conical shape is formed integrally with each movable contact piece actuator

12

, each rod

124

projecting downwardly from a predetermined position near the forward end

123

of the corresponding movable contact piece actuator

12

beyond the forward end

123

.

FIGS. 6

to

12

show a box (casing) used in the first embodiment of the rocker switch, and

FIG. 6

is a plan view showing the box,

FIG. 7

is a side view of

FIG. 6

as viewed from below,

FIG. 8

is a right-hand side view of

FIG. 6

,

FIG. 9

is a bottom view of

FIG. 6

,

FIG. 10

is a sectional view taken along the line

10

—

10

in FIG.

6

and looking in the direction indicated by the arrows,

FIG. 11

is a sectional view taken along the line

11

—

11

in FIG.

6

and looking in the direction indicated by the arrows, and

FIG. 12

is a sectional view taken along the line

12

—

12

in FIG.

6

and looking in the direction indicated by the arrows. This box

2

is a rectangular box the top of which is open and having a generally rectangular shape in plan, and the partition wall

21

is formed in the box

2

at the central portion thereof along the longitudinal direction of the box

2

, the partition wall

21

dividing the interior of the box

2

into two substantially same rooms. Since the rocker switch of this embodiment is a double pole-single throw (DPST) switch, there are required two rooms in which two sets of switch components or parts are accommodated respectively. For this reason, the interior of the box

2

is partitioned into two rooms by the partition wall

21

. However, in case of a single pole-single throw (SPST) switch, the interior of the box

2

may not be partitioned into two rooms. The partition wall

21

has a circular arc reentrancy

211

formed in the center of the top end portion thereof as is apparent from FIG.

10

. This reentrancy

211

is provided to prevent the top end portion of the partition wall

21

from coming into contact with the forward end portion

131

of the wall

13

of the operation button

1

constructed as described above, when the operation button

1

is mounted to the opening of the box

2

for seesaw movement. Further, it may be constructed that the reentrancy

211

is not provided in the partition wall

21

by lowering the height of the partition wall

21

by a little.

A flange

22

having a generally rectangular shape is formed integrally with the opening portion of the box

2

, and recesses

23

for mounting leaf springs are formed in a pair of opposed minor side walls of the box

2

, each recess

23

extending downwardly from a wall portion immediately below the flange

22

by a predetermined length. Leaf springs

24

each being curved outwardly are mounted in the corresponding recesses

23

, respectively. In addition, in a pair of opposed major side walls of the box

2

at the central portions thereof immediately below the flange

22

are formed through holes (bearing apertures)

25

for rotatably supporting the corresponding rotatable shafts

11

of the operation button

1

. These through holes

25

are situated on a straight line that is substantially at right angles to the surfaces of the major side walls.

FIGS. 13

to

15

show a movable contact piece used in the first embodiment of the rocker switch, and

FIG. 13

is a plan view of the movable contact piece,

FIG. 14

is a side view of

FIG. 13

as viewed from below, and

FIG. 15

is a bottom view of FIG.

13

. The movable contact piece

3

has a U-like shape (a hairpin shape) formed by folding back a strip made of a resilient or elastic member such as phosphor bronze, as is understood from

FIG. 14

, and in this embodiment, the strip is folded such that both strip portions of the U-like strip extending on both sides of the turning portion thereof differ in their lengths from each other.

A movable contact

31

is mounted to the free end portion of the longer strip portion (hereinafter, referred to as first strip portion)

32

, and cut-off portions

321

each having a generally rectangular shape in plan are symmetrically formed on both sides of the middle portion thereof, the cut-off portions

321

having substantially same shape and size with each other. This first strip portion

32

has a its forward portion beyond the cut-off portions

321

bended upwardly so as to have an inclination of predetermined degrees in

FIG. 14

, and the movable contact

31

is fixed to the forward end of this inclined portion.

An elongate aperture

333

is formed in the forward portion near the free end of the shorter strip portion (hereinafter, referred to as second strip portion)

33

, the elongate aperture

333

having a generally elliptical shape with its major axis situated in the longitudinal direction of the strip. As will be described later on, the rod

124

of one of the movable contact piece actuators

12

of the operation button

2

is inserted into the elongate aperture

333

with clearance or play between the rod

124

and the periphery of the elongate aperture

333

. Two recesses

332

are formed on the forward portion of the shorter strip portion

33

symmetrically at the both sides of the central portion of the elongate aperture

333

, the recesses

332

extending in the direction of the width of the strip (in the direction of the minor axis of the elongate aperture

333

). Since these recesses

332

are engaged with the generally circular arc-shaped tips

123

of the movable contact piece actuators

12

of the operation button

2

, the surfaces of the recesses

332

are formed to have circular arc shapes that conform to the shapes of the tips

123

of the movable contact piece actuators

12

, respectively.

FIGS. 16

to

18

show a movable contact piece support member used in the first embodiment of the rocker switch, and

FIG. 16

is a plan view of the movable contact piece support member,

FIG. 17

is a side view of

FIG. 16

as viewed from below, and

FIG. 18

is a right-hand side view of FIG.

16

. The movable contact piece support member

5

is manufactured by performing a metalwork for a sheet of metal having an increased rigidity by making the thickness thereof thicker, and comprises: a strip-like terminal portion (tab terminal)

51

; a movable contact piece support

52

formed integrally with one end portion in the longitudinal direction of the tab terminal

51

by bending the metal sheet substantially in the direction of making a right angle to the tab terminal

51

, the movable contact piece support

52

extending in the direction orthogonal to the tab terminal

51

; a retention piece

53

formed by bending the metal sheet substantially at right angles to the movable contact piece support

52

from one end portion thereof opposite to the tab terminal

51

in the same direction as that the tab terminal

51

is extending; and an upright piece

521

for supporting the movable contact piece, that is formed by bending the metal sheet substantially at right angles to the movable contact piece support

52

from one end portion in the longitudinal direction thereof in the opposite direction to that the tab terminal

51

and the retention piece

53

are extending.

As is apparent from

FIG. 17

, the tab terminal

51

has detent (engagement) pieces

511

for fixing the movable contact piece support member

5

to the box

2

, the detent pieces

511

projecting and being formed on both the left and right side edges of the tab terminal

51

above by a little the central portion thereof. As is clear from

FIG. 18

, a reentrant portion

520

having a generally rectangular shape is formed in the upper side of the movable contact piece support piece

521

, and in the reentrant portion

520

is positioned the central portion of the first strip portion

32

of the movable contact piece

3

discussed above. As can be understood from

FIG. 17

, the top end surface (the surface in the direction of thickness) that faces the reentrant portion

520

, of the movable contact piece support piece

521

has a sloped face

522

in the side thereof that the movable contact

31

projects, and the central portion of the first strip portion

32

of the movable contact piece

3

is put on the flat face

523

only remaining on the top end surface of the movable contact piece support piece

521

. In other words, this flat face

523

attains the same function as that of a protruding ridge. The cut-off portions

321

formed on the middle portion of the first strip portion

32

of the movable contact piece

3

are inserted into corresponding projections

524

formed on both sides of the reentrant portion

520

, respectively. These projections

524

have sloped surfaces inwardly inclined on their top end portions, respectively, which make easy a work that the movable contact piece

3

is assembled on the flat face

523

of the movable contact piece support piece

521

.

FIGS. 19

to

21

show a fixed contact piece used in the first embodiment of the rocker switch, and

FIG. 19

is a plan view of the fixed contact piece,

FIG. 20

is a side view of

FIG. 19

as viewed from below, and

FIG. 21

is a right-hand side view of FIG.

19

. This fixed contact piece

4

is manufactured by performing a metalwork for a sheet of metal having an increased rigidity by making the thickness thereof thicker, and comprises: a strip-like terminal portion (tab terminal)

42

; a fixed contact support

43

having a generally rectangular shape in plan and formed integrally with one end portion in the longitudinal direction of the tab terminal

42

by bending the metal sheet substantially in the direction of making a right angle to the tab terminal

42

; and a retention piece

44

formed by bending the metal sheet from one end portion thereof in the longitudinal direction thereof in the same direction as that the tab terminal

42

is extending and substantially at right angles to the fixed contact support

43

. A fixed contact

41

is mounted and fixed on the fixed contact support

43

. As is clear from

FIG. 20

, the tab terminal

42

has detent (engagement) pieces

421

for fixing the fixed contact piece

4

to the box

2

, the detent pieces

421

projecting and being formed on both the left and right side edges of the tab terminal

42

above by a little the central portion thereof.

On the other hand, through the bottom wall of the box

2

are formed slits

27

and

28

into which the tab terminal

42

of the fixed contact piece

4

and the tab terminal

51

of the movable contact piece support member

5

are to be inserted, respectively, as shown in

FIGS. 6

,

9

,

11

and

12

. In addition, as shown in

FIGS. 6

,

11

and

12

, grooves

29

and

30

in which the retention piece

44

of the fixed contact piece

4

and the retention piece

53

of the movable contact piece support member

5

are fitted, are formed in the inner surface of the bottom wall of the box

2

, respectively. The widths of the slits

27

and

28

are constant, but the lengths thereof are not constant and are longer in their portions from halfway toward the bottom surface in the direction of thickness of the bottom wall. That is, each of the slits

27

and

28

is formed such that a portion of its length from substantially the middle to the outer surface of the bottom wall in the direction of depth thereof is made longer than the remaining portion, and steps

271

and

281

are formed at substantially the middles of the slits

27

and

28

in the direction of depth thereof, respectively. As will be described later on, the detent or engagement pieces

421

and

511

of the tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

will be engaged with these steps

271

and

28

.

In addition, a partition wall

26

is formed integrally with the bottom wall of the box

2

, the partition wall

26

extending between the major side walls thereof. This partition wall

26

comprises a first protruding ridge portion

261

hanging down from the outer surface of the bottom wall of the box

2

and substantially in parallel with the minor side walls thereof and a second protruding ridge portion

262

projecting inwardly from the inner surface of the bottom wall of the box

2

substantially at right angles to the inner surface and substantially in parallel with the minor side walls thereof. The first protruding ridge portion

261

is located at substantially the central portion of the bottom surface of the box

2

, and the second protruding ridge portion

262

is located on a side of the inner surface near the slits

27

into which the tab terminals

42

of the fixed contact pieces

4

are to be inserted.

Next, there will be briefly explained a process of assembling the first embodiment of the rocker switch using the components described above.

At first, the tab terminal

42

of the fixed contact piece

4

is inserted into the slit

27

for the fixed contact piece formed through the bottom wall of the box

2

, and the tab terminal

42

of the fixed contact piece

4

is pulled out toward the outside. In this occasion, the retention piece

44

of the fixed contact piece

4

is fitted in the fit-in groove

29

. In the state that the tab terminal

42

of the fixed contact piece

4

has been completely pulled out toward the outside, the detent pieces

421

of the tab terminal

42

are forcedly bent outwardly by use of a jig so that they can be engaged with the corresponding steps

271

, respectively. Similarly, the remaining fixed contact piece

4

is secured by engaging the detent pieces

421

thereof with the corresponding steps

271

by use of a jig. Successively, the tab terminal

51

of the movable contact piece support member

5

is inserted into the slit

28

for the movable contact piece support member formed through the bottom wall of the box

2

, and the tab terminal

51

of the movable contact piece support member

5

is pulled out toward the outside. In this occasion, the retention piece

53

of the movable contact piece support member

5

is fitted in the fit-in groove

30

. In the state that the tab terminal

51

of the movable contact piece support member

5

has been completely pulled out toward the outside, the detent pieces

511

of the tab terminal

51

are forcedly bent outwardly by use of a jig so that they can be engaged with the corresponding steps

281

, respectively. Likewise, the remaining movable contact piece support member

5

is secured by engaging the detent pieces

511

thereof with the corresponding steps

281

by use of a jig.

Thereafter, the movable contact piece

3

is mounted on the movable contact piece support

52

of the movable contact piece support member

5

already secured to the bottom wall of the box

2

. Specifically, the cut-off portions

321

formed on the middle portion of the first strip portion

32

of the movable contact piece

3

are inserted into the projections

524

of the movable contact piece support piece

521

that stands erect from the movable contact piece support

52

in the state that the movable contact

31

projects outwardly of the sloped face

522

of the movable contact piece support piece

521

, the projections

524

being formed on both sides of the reentrant portion

520

, thereby to put the middle portion of the first strip portion

32

of the movable contact piece

3

on the flat face

523

of the movable contact piece support piece

521

.

In the state that two movable contact pieces

3

have been put on the corresponding flat faces

523

of the movable contact piece support piece

521

, the operation button

1

is positioned above the opening portion of the box

2

, and the forward end of the rod

124

of each of the movable contact piece actuators

12

is inserted into the oval aperture

333

of the corresponding one of the movable contact pieces

3

. Thereafter, the operation button

1

is pushed down from the upper side thereof so that the rotatable shafts

11

of the operation button

1

can be fitted in the bearing apertures

25

of the box

2

, respectively. Since each rotatable shaft

11

of the operation button

1

has been formed, as is clear from

FIG. 3

, such that the lower end portion below the central portion thereof has a sloped face inwardly inclined, the rotatable shafts

11

are relatively easily fitted in the bearing apertures

25

of the box

2

by depressing the operation button

1

. Thus, the first embodiment of the rocker switch according to the present invention is assembled.

When the rotatable shafts

11

of the operation button

1

have been fitted in the bearing apertures

25

of the box

2

, the rotatable shafts

11

of the operation button

1

is rotatably supported by the bearing apertures

25

of the box

2

so that the operation button

1

can seesaw. In addition, the rod

124

of each movable contact piece actuator

12

of the operation button

1

has been inserted into the oval aperture

333

of the corresponding one of the movable contact pieces

3

with a clearance or play between the rod

124

and the periphery of the oval aperture

333

, and each movable contact piece actuator

12

is in a situation that its circular arc-shaped tip

123

has been engaged with the circular arc-shaped recess

332

of corresponding one of the movable contact pieces

3

. Since each movable contact piece

3

merely has been swingably engaged with the reentrant portion

520

of the movable contact piece support piece

521

as stated above, it is not in stable state. The stable position of the movable contact piece

3

is either one of two positions one of which is switch-on position where the movable contact

31

is in contact with the fixed contact

41

and the other of which is switch-off position where the movable contact

31

is away from the fixed contact

41

by a predetermined distance. Accordingly, when the rotatable shafts

11

of the operation button

1

have been fitted in the bearing apertures

25

of the box

2

, the movable contact piece

3

swingingly moves to either one of the two positions, that is, the switch-on position where the movable contact

31

is in contact with the fixed contact

41

and the switch-off position where the movable contact

31

is away from the fixed contact

41

by a predetermined distance, and hence the operation button

1

also rotates and stops at a position corresponding to either one position.

FIG. 22

is a generally sectional view showing the state that the operation button

1

is stopping at the switch-off position where the movable contact

31

is away from the fixed contact

41

by a predetermined distance, and

FIG. 23

is a generally sectional view showing the state that the operation button

1

is stopping at the switch-on position the movable contact

31

is in contact with the fixed contact

41

. As is clear from

FIG. 22

, in case the movable contact

31

is situated at the switch-off position where it is away from the fixed contact

41

by a predetermined distance, the turning portion of the movable contact piece

3

is in contact with the top surface of the movable contact piece support

52

of the movable contact piece support member

5

, and therefore, the movable contact piece

3

is in stable state.

As is apparent from the foregoing discussions, in the first embodiment of the rocker switch, it is possible to mount or assemble the fixed contact piece

4

and the movable contact piece support member

5

in the box

2

and to secure them simply and easily with accuracy and stability. In addition, the rocker switch is constructed such that the forward end of the rod

124

of each of the movable contact piece actuators

12

of the operation button

1

is inserted into the oval aperture

333

of the corresponding one of the movable contact pieces

3

, and then, the operation button

1

is pushed down from the upper side thereof so that the rotatable shafts

11

of the operation button

2

are fitted in the bearing apertures

25

of the box

2

, respectively. As a result, when assembled, the operation button

1

can accurately and stably be mounted to the box

2

for seesaw movement without any trouble or accident that the movable contact piece

3

falls off the movable contact piece support member

5

or the movable contact piece

3

is injured or damaged.

Moreover, the rocker switch is constructed such that the rod

124

of each movable contact piece actuator

12

of the operation button

1

is inserted into the oval aperture

333

of the corresponding one of the movable contact pieces

3

with a clearance or play between the rod

124

and the periphery of the oval aperture

333

as well as the circular arc-shaped tip

123

of each movable contact piece actuator

12

is engaged with the circular arc-shaped recess

332

of corresponding one of the movable contact pieces

3

thereby to operate as if they are linked. In other words, engagement between the circular arc-shaped tip

123

of each movable contact piece actuator

12

of the operation button

1

and the circular arc-shaped recess

332

of the corresponding movable contact piece

3

is not in the sliding friction state as in the prior art but in the rolling friction state. As a result, when the operation button

1

is operated, there can be obtained actual feeling that the operation button

1

swings lightly and smoothly (without feeling a resistance thereto) as well as that the operation button

1

has positively stopped at its switch-on position or switch-off position. That is, feeling in actuation of the operation button

1

comes to much favorable or excellent. Furthermore, since the conical rod

124

of each movable contact piece actuator

12

of the operation button

1

is inserted into the oval aperture

333

of the corresponding one of the movable contact pieces

3

with a clearance between the rod

124

and the periphery of the elongate aperture

333

, it is ensured that there occurs no trouble or accident that a displacement in position of each movable contact piece

3

occurs or the movable contact piece falls off due to an external shock, and hence it is possible to make the operation of the rocker switch stable.

The middle portion of the first strip portion

32

of the movable contact piece

3

is put on the flat face

523

of the movable contact piece support piece

521

which functions as a protruding ridge by the sloped face

522

of the movable contact piece support piece

521

, and therefore, the movable contact piece

3

and the movable contact piece support member

5

are electrically and mechanically brought into contact with each other without fail. In addition, since the movable contact piece

3

is put on the flat face

523

of the movable contact piece support piece

521

which functions as a protruding ridge, the movable contact piece

3

can quickly be swung. In particular, because of provision of the sloped face

522

, not only the swinging operation of the movable contact piece

3

to its switch-off position but also the swinging operation of the movable contact piece

3

to its switch-on position becomes very quick. Moreover, in case of operating the movable contact piece

3

in the reverse direction, the conical rod

124

is inserted into the oval aperture

333

of the corresponding one of the movable contact pieces

3

with a clearance between the rod

124

and the periphery of the oval aperture

333

, and hence any displacement does not occur in positions where the movable contact piece actuators

12

of the operation button

1

push the corresponding movable contact pieces

3

. For that reason, more stable reverse operation of the movable contact pieces

3

is obtained, and more favorable or excellent feeling in actuation of the operation button

1

is also obtained as well as there is ensured the quick reverse operation of the movable contact piece

3

with a click. The more quick reverse operation of the movable contact piece

3

results in lesser bounce time in throwing the movable contact piece

3

to its switch-on position as well as smaller arc occurring in throwing the movable contact piece

3

to its switch-off position. As a result, wear and tear of the contacts are further restrained and there can be provided the contacts the lifetime of which is much more longer.

Next, there will be described a second embodiment of the rocker switch according to the present invention in detail with reference to

FIGS. 24

to

26

.

FIG. 24

is a generally sectional view showing the switch-on state of a second embodiment of the rocker switch according to the present invention,

FIG. 25

is a bottom view of a box used in the second embodiment of the rocker switch according to the present invention, and

FIG. 26

is a plan view showing the state that two fixed contact pieces and two movable contact piece support members have been mounted in the box shown in FIG.

25

. The second embodiment of the rocker switch differs, mainly in the structure of the box, specifically, in the structure of the bottom wall of the box, from the box of the above-described first embodiment. Therefore, in

FIGS. 24-26

, elements, components, members and/or portions corresponding to those in

FIGS. 1-23

will be denoted by the same reference numbers and/or characters attached thereto, and the explanation of the operation button

1

, the movable contact piece

3

, the movable contact piece support member

5

, and the fixed contact piece

4

will be omitted unless necessary.

As already described, TAB 187 terminal of IEC (International Electrotechnical Commission) standard is used as a terminal portion (tab terminal) of a rocker switch of rated current 10A type, and it is necessary that TAB 250 terminal of IEC standard is used as a terminal portion (tab terminal) of a rocker switch of rated current 16A type. The width of TAB 187 terminal is 4.75 mm, while the width of TAB 250 terminal is 6.35 mm. Therefore, the width of TAB 250 terminal is wider by 1.6 mm than that of TAB 187 terminal.

The rocker switch of the first embodiment described above is one of rated current 10A type, and both the tab terminal

42

of the fixed contact piece

4

and the tab terminal

51

of the movable contact piece support member

5

are TAB 187 terminal of IEC standard and so the widths thereof are 4.75 mm. A distance between adjacent tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

is thoroughly larger than the insulation distance or creepage distance of IEC standard (larger than 3 mm). However, in case the slits

27

and

28

formed through the bottom wall of the box

2

of the rocker switch of the first embodiment are lengthened in their lengths so as to conform to the width 6.35 mm of TAB 250 terminal and a rocker switch of rated current 16A type is assembled by inserting TAB 250 terminals into the slits

27

and

28

, a distance between adjacent tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

becomes shorter than the insulation distance of IEC standard, and hence such rocker switch does not fulfill the IEC standard.

The rocker switch of the second embodiment is one of rated current 16A type in which there is used a box having the same width and depth (the lengths of the major side direction and of the minor side direction of the box

2

) as those of the box used in the rocker switch of the first embodiment and TAB 250 terminals of IEC standard are inserted into the box. The rocker switch of the second embodiment has an insulation distance or creepage distance between adjacent tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

, which fulfills the IEC standard.

The box

2

used in the rocker switch of the second embodiment is also a rectangular box the top of which is open and having a generally rectangular shape in plan like the box

2

used in the rocker switch of the first embodiment, and a partition wall

21

is formed in the box

2

at the central portion thereof along the longitudinal direction of the box

2

, the partition wall

21

dividing the interior of the box

2

into two substantially same rooms. Since the rocker switch of this second embodiment is also a double pole-single throw (DPST) switch, there are required two rooms in which two sets of switch components are accommodated respectively. For this reason, the interior of the box

2

is partitioned into two rooms by the partition wall

21

. A flange

22

having a generally rectangular shape is formed integrally with the opening portion of the box

2

, and recesses

23

for mounting leaf springs are formed in a pair of opposed minor side walls of the box

2

, each recess

23

extending downwardly from a wall portion immediately below the flange

22

by a predetermined length. Leaf springs

24

each being curved outwardly are mounted in the corresponding recesses

23

, respectively.

As shown in

FIG. 25

, through the bottom wall of the box

2

are slantingly formed slits

227

and

228

into which the tab terminal

42

of each fixed contact piece

4

and the tab terminal

51

of each movable contact piece support member

5

are to be inserted, respectively, these slits

227

and

228

being extending from the four corners of the bottom wall in the direction that forms a predetermined acute angle with the major side wall of the box

2

. Like the slits

27

and

28

of the first embodiment, the widths of these slits

227

and

228

are constant, but the lengths thereof are not constant and are longer in their portions from halfway toward the bottom surface in the direction of thickness of the bottom wall. That is, each of the slits

227

and

228

is formed such that a portion of its length from substantially the middle to the outer surface of the bottom wall in the direction of depth thereof is made longer than the remaining portion, and steps

271

and

281

are formed at substantially the middles of the slits

227

and

228

in the direction of depth thereof, respectively. The detent or engagement pieces

421

and

511

of the tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

are engaged with these steps

271

and

28

. Further, though not shown, grooves in which a retention piece of each fixed contact piece

4

and a retention piece of each movable contact piece support member

5

are fitted, are formed in the inner surface of the bottom wall of the box

2

, respectively. In addition, as can easily be understood from

FIG. 26

, the tab terminal

42

of the fixed contact piece

4

and the tab terminal

51

of the movable contact piece support member

5

are bent downwardly such that they form an angle with the side edges of the fixed contact support

43

and the movable contact piece support

52

respectively, this angle being substantially the same as the angle of inclination of the slits

227

and

228

. Further, the movable contact piece support

52

of the movable contact piece support member

5

has its shape in plan that is somewhat different from that of the movable contact piece support

52

used in the first embodiment, as shown in

FIG. 26

, because the tab terminal

51

thereof is bent vertically downwardly such that it forms an angle with the side edge of the movable contact piece support

52

.

A partition wall

200

formed integrally with the bottom wall of the box

2

comprises: a first protruding ridge portion

201

hanging down to a position a little beyond the forward ends of the tab terminal

42

of the fixed contact piece

4

and the tab terminal

51

of the movable contact piece support member

5

from substantially the central portion of the outer surface of the bottom wall substantially in parallel with the minor side walls thereof; a second protruding ridge portion

202

hanging down to a position a little beyond the forward ends of the tab terminal

42

of the fixed contact piece

4

and the tab terminal

51

of the movable contact piece support member

5

from substantially the central portion of the outer surface of the bottom wall substantially in parallel with the major side walls thereof; and a third protruding ridge portion

203

projecting inwardly from the inner surface of the bottom wall substantially at right angles to the inner surface and substantially in parallel with the minor side walls thereof. The first and third protruding ridge portions

201

and

203

extend between the major side walls, respectively, and the second protruding ridge portion

202

extends between the minor side walls. In practice, the first and second protruding ridge portions

201

and

202

are formed as a united partition wall having a generally cross shape in plan as shown in FIG.

25

. These protruding ridge portions

201

and

202

isolate the tab terminals

42

of the two fixed contact pieces

4

and the tab terminals

51

of the two movable contact piece support members

5

from one another when the four tab terminals are pulled out toward the outside through the corresponding slits

227

and

228

and are secured by use of their detents. Further, the third protruding ridge portion

203

is situated on a side of the inner surface near the slits

227

into which the tab terminals

42

of the fixed contact pieces

4

are to be inserted.

In this manner, with the construction that the slits

227

and

228

into which the tab terminals

42

of the fixed contact pieces

4

and the tab terminals

51

of the movable contact piece support members

5

are inserted, are obliquely formed to extend from the four corners of the bottom wall of the box

2

in the direction that forms a predetermined acute angle with the major side wall of the box

2

and that the four tab terminals are separated by the first and second protruding ridge portions

201

and

202

formed as a united partition wall having a generally cross shape in plan, an insulation or creepage distance between adjacent tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

thoroughly fulfills the IEC standard. For example, if an angle of inclination of the slits

227

and

228

against the major side wall is set to about 15°, a straight distance between the side edge of the tab terminal

42

of the fixed contact piece

4

inserted into the corresponding slit

227

and the end portion of the first protruding ridge portion

201

as well as a straight distance between the side edge of the tab terminal

51

of the movable contact piece support member

5

inserted into the corresponding slit

228

and the end portion of the first protruding ridge portion

201

are both about 2.38 mm. If the thickness of the first protruding ridge portion

201

is set to 1 mm, the creepage distance between adjacent tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

comes to about 5.76 mm, which is thoroughly larger than the insulation distance of IEC standard that is larger than 3 mm. In addition, the straight distance between adjacent tab terminals

42

and

51

of the fixed contact piece

4

and of the movable contact piece support member

5

is larger than 3 mm. Accordingly, a sufficient dielectric strength is obtained. Further, the creepage distance and straight distance between the tab terminal

42

of the fixed contact piece

4

and the tab terminal

51

of the movable contact piece support member

5

are increased as an angle of inclination of the slits

227

and

228

against the major side wall grows larger.

Thus, there is provided the rocker switch of rated current 16A type in which there is used a box having the same width and depth as those of the box of a rocker switch of rated current 10A type and TAB 250 terminals of IEC standard are inserted into the box. It is needless to say that same function and effects as those of the first embodiment can also be obtained by this rocker switch, and yet, this rocker switch can be mounted on various kinds of machines, apparatus, equipments, instruments or the like each of which does not have a space in which a rocker switch having its width and depth larger than those of the rocker switch of rated current 10A type can be accommodated. Consequently, there is obtained an advantage that OA machines or equipments, amusement and game machines, measurement instruments, medical instruments and the like, for example, can be modified to ones each having larger rated current/voltage value without increasing sizes thereof. Further, the height (the length in the direction of forming right angles with the bottom wall of the box

2

) of the rocker switch of the second embodiment becomes higher by a difference in length between TAB 187 terminal and TAB 250 terminal that is longer than TAB 187 terminal. Since a power supply cable or the like will be connected to each tab terminal, there is usually a slight room in a space in the direction of height thereof, and hence the rocker switch of the second embodiment can be mounted instead of the rocker switch of rated current 10A type without occurrence of any problem.

Next, there will be described a third embodiment of the rocker switch according to the present invention in detail with reference to

FIGS. 27

to

32

.

FIG. 27

is a plan view showing a conductive resilient piece used in a third embodiment of the rocker switch according to the present invention,

FIG. 28

is a left-hand side view of

FIG. 27

,

FIG. 29

is a side view of

FIG. 27

as viewed from below,

FIG. 30

is a generally perspective view showing the state that the resilient piece shown in

FIGS. 27-29

has been fitted in the movable contact piece support piece

521

that stands erect from the movable contact piece support

52

of the movable contact piece support member

5

used in the second embodiment,

FIG. 31

is a plan view showing the state that the resilient piece shown in

FIGS. 27-29

has been fitted in both of the two movable contact piece support members

5

shown in FIG.

26

and further, the movable contact piece

3

shown in

FIGS. 13-15

has been mounted on one of the two resilient pieces, and

FIG. 32

is a generally sectional view showing the switch-on state of a third embodiment of the rocker switch according to the present invention.

The third embodiment of the rocker switch differs from the second embodiment of the rocker switch only in the point that in the second embodiment of the rocker switch, the conductive resilient piece

6

shown in

FIGS. 27-29

is fitted in the movable contact piece support piece

521

standing erect from the movable contact piece support

52

of the movable contact piece support member

5

and further, the movable contact piece

3

shown in

FIGS. 13-15

is mounted on the conductive resilient piece

6

. That is, in the third embodiment, on the movable contact piece support piece

521

is mounted the movable contact piece

3

through the conductive resilient piece

6

therebetween. Therefore, in

FIGS. 27-32

, elements, components, members and/or portions corresponding to those in

FIGS. 1-26

will be denoted by the same reference numbers and/or characters attached thereto, and the explanation of the operation button

1

, the movable contact piece

3

, the movable contact piece support member

5

, and the fixed contact piece

4

will be omitted unless necessary.

The conductive resilient piece

6

is a spring manufactured by performing a metalwork for an electrically conductive strip made of a resilient or elastic member such as phosphor bronze, and as shown in

FIGS. 27-29

, it comprises: a resilient piece body

60

having a generally rectangular shape in plan; protrusions

61

bent obliquely and upwardly toward the outside from the side edge of each of the major sides of the resilient piece body

60

at predetermined intervals, two protrusions

61

being formed on each side edge thereof and each having a generally truncated triangular shape; and a pair of opposed retentive pieces

62

formed by bending both side portions in the longitudinal direction of the resilient piece body

60

over a predetermined length thereof at an angle that is a little larger than a right angle.

Each of the four protrusions

61

has its forward end

611

bent substantially in parallel with the surface of the resilient piece body

60

but slightly upwardly as shown in

FIG. 28

, and the two protrusions

61

located on the one side edge and the two protrusions

61

located on the other side edge are formed face to face on the resilient piece body

60

. A pair of through holes

63

is formed in the both side portions in the longitudinal direction of the resilient piece body

60

at the central portions thereof, and extends to the corresponding retentive pieces

62

. These through holes

63

have their shapes and sizes fitted in the projections

524

formed on the both sides of the reentrant portion

520

in the movable contact piece support piece

521

standing erect from the movable contact piece support

52

with a clearance or play between the periphery of each through hole

63

and each projection

524

. Further, as shown in

FIG. 30

, adjacent two protrusions

61

are formed such that they are situated between the opposed inner walls of the two projections

524

.

As shown in

FIG. 29

, a pair of the retentive pieces

62

is slightly inclined inwardly of the resilient piece body

60

, and when the resilient piece

6

is attached to the movable contact piece support piece

521

by fitting a pair of the through holes

63

of the resilient piece

6

in a pair of the projections

524

of the movable contact piece support piece

521

with a clearance therebetween, as shown in

FIG. 30

, a pair of the retentive pieces

62

is pressed outwardly by the outer walls of the projections

524

so that they take substantially upright state. In other words, a pair of the retentive pieces

62

nips a pair of the projections

524

therebetween. Accordingly, the two retentive pieces

62

abut and press against the corresponding outer walls of the projections

524

by their resilient forces, and hence the resilient piece

6

is held in the reentrant portion

520

of the movable contact piece support

52

in the state that the bottom surface of the resilient piece body

60

is put on the flat face

523

of the movable contact piece support piece

521

. In addition, as can be understood from

FIG. 31

, the width of each retentive piece

62

is considerably wider than that of the wall surface of the projection

524

against which each retentive piece

62

abuts. Therefore, each retentive piece

62

is sufficiently in contact with the wall surface of the corresponding projection

524

of the movable contact piece support piece

521

, and they are electrically well connected with each other. As a result, the resilient piece

6

and the movable contact piece support member

5

are also electrically well connected with each other due to the electrical contact between the bottom surface of the resilient piece body

60

and the flat face

523

of the movable contact piece support piece

521

as well as the electrical contact between the two retentive pieces

62

and the corresponding projections

524

of the movable contact piece support piece

521

. Further, in this embodiment, the height of each retentive piece

62

is set to be approximately equal to the height of the corresponding projection

524

of the movable contact piece support piece

521

, and it is needless to say that the height of each retentive piece

62

is not limited to such value.

On the other hand, as shown in

FIG. 31

, the movable contact piece

3

is put on the resilient piece

6

. In this occasion, the cut-off portions

321

(see

FIG. 15

) formed on the middle portion of the first strip portion

32

of the movable contact piece

3

are inserted into the corresponding projections

524

of the movable contact piece support piece

521

with a clearance between the cut-off portions

321

and the projections

524

, and the middle portion of this first strip portion

32

is mainly put on the resilient piece

6

. Accordingly, the bottom surface of the first strip portion

32

of the movable contact piece

3

is in contact with the forward ends

611

of the four protrusions

61

of the resilient piece

6

. As discussed above, since the second strip portion

33

of the movable contact piece

3

is depressed by the movable contact piece actuator

12

of the operation button

1

, the first strip portion

32

is also depressed toward the resilient piece

6

. Since each of the four protrusions

61

of the resilient piece

6

has an elastic force, the bottom surface of the first strip portion

32

of the movable contact piece

3

and the forward ends

611

of the four protrusions

61

of the resilient piece

6

are in pressure contact state with each other. In addition, the forward ends

611

of the four protrusions

61

of the resilient piece

6

are depressed by the bottom surface of the first strip portion

32

of the movable contact piece

3

, which results in that the central portion of the resilient piece body

60

is warped upwardly as shown in FIG.

32

and comes into contact with the bottom surface of the first strip portion

32

of the movable contact piece

3

. Consequently, the movable contact piece

3

is electrically well connected with the resilient piece

6

.

The two retentive pieces

62

are merely in pressure contact with the corresponding projections

524

of the movable contact piece support piece

521

and are not in secured state therewith. Moreover, the two retentive pieces

62

nip the projections

524

therebetween by only their elastic forces. Accordingly, as the movable contact piece

3

is rocked, the resilient piece

6

is also rocked with ease to get to the switch-on position shown in

FIG. 32

or the switch-off position not shown where the movable contact

31

is away from the fixed contact

41

. Since the two retentive pieces

62

are in pressure contact with the corresponding projection

524

of the movable contact piece support piece

521

and the width of each retentive piece

62

is considerably wider than that of the projection

524

, even during rocking movement thereof, each retentive piece

62

is in well contact with the wall surface of the corresponding projection

524

. As a result, the resilient piece

6

and the movable contact piece support member

5

are always in well electrically connection with each other, and yet, since the forward ends

611

of the four protrusions

61

of the resilient piece

6

are in pressure contact with the bottom surface of the first strip portion

32

of the movable contact piece

3

, the resilient piece

6

and the movable contact piece

3

are also always in well electrically connection with each other. Thus, when a bounce occurs, no arc occurs between the movable contact piece

3

and the movable contact piece support piece

521

and a lifetime of these components are greatly lengthened.

In such way, with the construction that the resilient piece

6

made of a conductive elastic member (a spring member) is put between the flat face

523

of the movable contact piece support piece

521

and the movable contact piece

3

in the state that the resilient piece

6

is in pressure contact with both the support piece

521

and the movable contact piece

3

, not only the same function and effects as those of the second embodiment are obtained but also occurrence of an arc between the movable contact piece

3

and the movable contact piece support piece

521

due to a bounce of the movable contact piece on turning the rocker switch on or off, can perfectly be prevented because the movable contact piece support piece

521

and the movable contact piece

3

are always in well electrically connection through the conductive resilient piece

6

. Consequently, a lifetime of the switch is considerably lengthened. In addition, since the conductive resilient piece

6

is mounted to the movable contact piece support piece

521

by merely pressing and abutting a pair of the retentive pieces

62

thereof against the projections

524

of the movable contact piece support piece

521

to bring into contact therewith, the mounting work of the resilient piece

6

is easy. Accordingly, there occurs no problem in working efficiency. Further, it goes without saying that the number of the protrusions

61

is not limited to four.

In the first, second and third embodiments, it is constructed that the detent (engagement) pieces

421

and

511

of the tab terminals

42

and

51

are formed integrally therewith on the both side edges in the direction of the widths thereof, the detent pieces

421

and

511

projecting in the direction of the widths of the tab terminals

42

and

51

, and the tab terminals

42

and

51

are secured by forcedly bending the detent pieces

421

and

511

outwardly in the direction of the widths thereof and engaging them. Accordingly, there is obtained an advantage that the tab terminals

42

and

51

are firmly fixed on the bottom wall of the box

2

without increasing sizes in the widths of the tab terminals

42

and

51

as in the prior art.

Further, though there have been described the embodiments in which the present invention is applied to a double pole-single throw switch, it is needless to say that the present invention can also be applied to various types of rocker switches such as a single pole-single throw switch, a double pole-double throw switch and the like, and that the same function and effects can be obtained. In addition, in the second embodiment, there has been illustrated a case that a rocker switch of rated current 10A type can be used as one of rated current 16A type without increasing the external sizes of its box. It goes without saying that the present invention can also be applied to a case in which a rocker switch having a predetermined rated current/voltage is constructed such that it can be used as another rocker switch having its rated current/voltage larger than the predetermined rated current/voltage without increasing the external sizes thereof, and that the same function and effects can be obtained.

As described above, according to the present invention, it is possible to mount or assemble the fixed contact piece and the movable contact piece support member in the box and to secure them simply and easily with accuracy and stability. In addition, engagement between each movable contact piece actuator of the operation button and the movable contact piece is in the rolling friction state. As a result, there can be obtained actual feeling that the operation button swings lightly and smoothly (without feeling a resistance thereto) as well as that the operation button has positively stopped at its switch-on position or switch-off position, and feeling in actuation of the operation button comes to much favorable or excellent. Furthermore, the quick swinging operation of the movable contact piece is made possible and the more stable reverse operation of the movable contact pieces is obtained, which results in lesser bounce time in throwing the movable contact piece to its switch-on position as well as smaller arc occurring in throwing the movable contact piece to its switch-off position. As a result, wear and tear of the contacts are further restrained and there can be provided the contacts the lifetime of which is much more longer.

While the present invention has been described with regard to the preferred embodiments shown by way of example, it will be apparent to those skilled in the art that various modifications, alterations, changes, and/or minor improvements of the embodiments described above can be made without departing from the spirit and the scope of the present invention. Accordingly, it should be understood that the present invention is not limited to the illustrated embodiments, and is intended to encompass all such modifications, alterations, changes, and/or minor improvements falling within the scope of the invention defined by the appended claims.

Number	Date	Country	Kind
2003-073588	Mar 2003	JP
2003-073589	Mar 2003	JP

Number	Name	Date	Kind
5158172	Roeser et al.	Oct 1992	A
5660270	Martin et al.	Aug 1997	A
5662213	Kattler et al.	Sep 1997	A
5896768	Cranick et al.	Apr 1999	A
6103982	Chien	Aug 2000	A
6388221	Rudolph et al.	May 2002	B1
6600122	Czarnecki et al.	Jul 2003	B1

Number	Date	Country
3224949		JP
5-1870	Jan 1993	JP
6035333	Jan 1994	JP
0855542	Feb 1996	JP
01195955	Jul 2001	JP

Rocker switch

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (2)

US Referenced Citations (7)

Foreign Referenced Citations (5)