Electricity: circuit makers and breakers – Snap – Double snap
Reexamination Certificate
2000-07-26
2001-07-17
Friedhofer, Michael (Department: 2832)
Electricity: circuit makers and breakers
Snap
Double snap
C200S533000, C200S551000
Reexamination Certificate
active
06262383
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a tact switch and its movable contact piece, and particularly to a tact switch in which the flipping-over or reversing action of the cup-shaped curved portion of the movable contact piece will cause the contact section disposed around the periphery of the cup-shaped portion to come into contact with a plurality of fixed contact plates to establish electrical conduction between the fixed contact plates, and the movable contact piece.
U.S. patent application Ser. No. 09/414,067 (filed on Oct. 7, 1999) assigned to the same assignee as the present application proposes a tact switch of the type described herein having external appearances as shown in
FIGS. 1A
,
1
B and
1
C. This tact switch comprises a housing, a top lid, an actuator member and a movable contact piece.
FIG. 2
is an exploded, perspective view of the tact switch. The construction of the various parts of the tact switch will first be described with reference to FIG.
2
.
The housing
11
is made from a synthetic resin material in the form of a box having an open top. Exposed within the box are the inner end portions of four insert-molded fixed contact plates
13
one at each of the four corners of the bottom surface of the box surrounded by side walls
12
. Formed in the center of the bottom surface is a circular pedestal
14
having a stud-like protrusion
15
upstanding therefrom. The other end portion of each of the fixed contact plates
13
extends out of the housing
11
and terminates in a terminal
13
a.
One pair of the side walls
12
defining major sides of the housing
11
has notches
16
and
17
, respectively cut down from the top edges of the side walls in the middle thereof. One
16
of the notches further has a lower recess
18
formed in the center thereof. The bottom surface of the recess
18
is arranged to lie at the same elevation as the bottom surface of the notch
17
in the other side wall
12
.
On the other hand, the other pair of the side walls
12
defining minor sides of the housing
11
has notches
19
cut down from the top edges of the side walls and diverging or increasing in width downwardly toward the bottom surface as shown. Each of the notches
19
has one vertically extending inner side surface
19
a
and the opposed downwardly outwardly inclined or tapered inner side surface
19
b.
A stepped portion or ledge
21
extends from the vertical side surface
19
a
of one of the notches
19
along the interior of that side wall
12
in which the notch
16
is formed to the vertical side surface
19
a
of the other notch
19
, with the bottom surface of the stepped portion
21
being flush with the bottom surfaces of the notches
19
and somewhat lower than the bottom surface of the recess
18
.
The side walls
12
in which the notches
16
,
17
are formed, respectively have engagement lugs
22
protruding from the outer surfaces thereof at the upper corners, while the other side walls
12
in which the notches
19
are formed have engagement recesses
23
formed in the outer surfaces thereof in the center adjacent the top edges.
The top lid
24
adapted to be mounted on the top of the housing
11
to close the open top of the housing
11
is made of metal and comprise a rectangular top plate
25
having engagement flaps
26
extending and folded down from the opposed minor sides thereof and L-shaped latch tabs
27
extending from the opposed major sides adjacent opposite ends thereof.
The movable contact piece
28
is made in the shape of a cup having small marginal flat portions from a spring material such as a phosphor bronze plate. In the example illustrated, it is made from a generally rectangular sheet so as to define a curved section
29
with longitudinal opposite end portions of the sheet left. The curved section
29
is formed in the center with a positioning hole
31
. In addition, the movable contact piece
28
has a notch
32
formed in each of the opposite minor sides in the middle thereof to define contact portions
33
at the opposite ends of the minor side.
The actuator member
34
for press-actuating the movable contact piece
28
is made of a synthetic resin material and comprises two actuating bars
35
, a guide bar
36
extending between and parallel to the two actuating bars
35
and an operating portion
37
connecting the two actuating bars
35
and the guide bar
36
together on one ends thereof.
The guide bar
36
terminates in a forward broadened end portion as shown. Each of the actuating bars
35
has an actuating protrusion
38
formed on its lower surface. It is to be
25
noted that the guide bar
36
has a thickness slightly greater than the actuating bars
35
.
The assembly of the tact switch is carried out by assembling the movable contact piece
28
and the actuator member
34
sequentially into the housing
11
and closing it by the top lid
24
. During this operation of assembly, the movable contact piece
28
is assembled with the curved section
29
projecting downwardly convexly with the apex of thereof resting on the pedestal
14
and the positioning hole
31
fitted over the protrusion
15
for positioning the contact piece.
FIG. 3
illustrates the movable contact piece
28
assembled in the housing.
FIG. 4A
illustrates the actuator member
34
assembled from above onto the sub-assembly shown in FIG.
3
. It is seen that the operating portion
37
of the actuator member
34
is located outside of the housing
11
with the outer portions of the forward ends of the two actuating bars
35
slightly dipped under the inclined surfaces
19
b
of the housing
11
.
The root portions (toward the joints to the operating portion
37
) of the two actuating bars
35
and the guide bar
36
are located over the notches
16
and the recess
18
, respectively of the housing
11
. That is, the actuating bars
35
and the guide bar
36
are inserted into the housing
11
through the notches
16
and the recess
18
. The forward end of the guide bar
36
is guided in the notch
17
.
In this state as shown in
FIG. 4A
, the actuating protrusions
38
provided on the forward ends of the actuating bars
35
lying on the marginal portions of the movable contact piece
28
in slight resilient contact therewith.
The securement of the top lid
24
to the housing
11
is effected by engaging the L-shaped latch tabs
27
with the respective engagement lugs
22
. In doing so, the two engagement flaps
26
are fitted into the respective engagement recesses
23
whereby the assembly of the tact switch as shown in
FIGS. 1A
,
1
B and
1
C is completed.
With the tact switch constructed as described above, when the operating portion
37
is pushed inwardly parallel to the bottom surface of the housing
11
, the forward end portions of the two actuating bars
35
are depressed downwardly toward the bottom surface of the housing
11
as they are guided by the inclined surfaces
19
b.
Specifically, the actuating bars
35
are flexed as shown in
FIG. 5B
to cause the actuating protrusions
38
to press down on the marginal portions of the movable contact piece
28
.
This pressing operation causes the movable contact piece to be inverted or flipped over in its convexity-concavity orientation to thereby bring its contact portions
33
into contact with the corresponding fixed contact plates
13
. This contact brings the four fixed contact plates
13
into conduction with each other to turn the switch on. It should be noted that
FIG. 4B
illustrated the operating portion
37
as being pushed inwardly with the top lid removed while
FIG. 6
illustrates the movable contact piece
28
in its reversed state in the broken lines.
When the pushing operation on the operating portion
37
is released, the movable contact piece
28
is flipped over back to its original curved position due to its elastic restoring force to turn the switch off while at the same time the movable contact actuator member
34
is forced out of the housing
11
whereby the operating portion
37
is restored to its original position, that is, to the non
Connolly Bove & Lodge & Hutz LLP
Friedhofer Michael
Sagami Electric Company, Ltd.
LandOfFree
Tact switch and its movable contact piece does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Tact switch and its movable contact piece, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tact switch and its movable contact piece will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2514052