Information
-
Patent Grant
-
6483416
-
Patent Number
6,483,416
-
Date Filed
Thursday, February 22, 200123 years ago
-
Date Issued
Tuesday, November 19, 200222 years ago
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Inventors
-
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 337 59
- 337 64
- 337 69
- 337 70
- 337 72
- 337 113
- 337 126
- 337 140
- 337 414
- 337 347
- 029 622
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International Classifications
-
Abstract
The present invention relates to an overload protection device of a press type switch in which the switch main body has slide grooves within the bouncing range of the free end of the conductive strip. The shape of the slide grooves is formed by a plurality of slide rails. A push-pull element is pivotably connected to the inside of the press button. A cross bar is fitted to the bottom of the push-pull element while both ends of the cross bar are disposed in the slide grooves. Accordingly, the push-pull element is able to change path and locating position in the slide grooves. Moreover, the conductive strip can be controlled in on/off-state by means of the force in different directions. Beside, the free end of the conductive strip is kept in an independent state so that the conductive strip is transformed into the off-state in case of overload. Consequently, the safety of the user can be ensured.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an overload protection device of a press type switch, and more particularly to a press type switch in which a push-pull element controlling the switching of a conductive strip slides along a preset path of an 8-shaped slide groove. Accordingly, this switch has not only the function of on/off control, it can also enable the conductive strip to carry out an automatic disconnection in case of overload so that the safety of the user is ensured.
2. Description of the Prior Art
The types of switches are various. Commercially available switches like see-saw switch, press type switch, spring type switch, microswitch, etc. differ from one another in configuration which are designed to meet the using requirements and habits of the users. Regarding the technical features of the see-saw switch, the inventor of the present invention has disclosed a few previously approved cases so that it won't be described more hereinafter. The present invention is an improvement of the two-stage press switch. A conventional two-stage press switch, as shown in
FIGS. 1 through 4
, utilizes a two-stage press element
2
projecting above the housing
1
to move a push rod
21
, thereby controlling the conductive strip
3
in a connection or disconnection state. The press element
2
includes a heart-shaped slide groove
22
at inner side thereof which has several slide rails of different height and a U-piece
23
. The top of the U-piece
23
is pivotably connected to the housing I while the bottom thereof is situated in the slide groove
22
. When the press element
2
is pressed downwards, the top of the slide groove
22
is engaged at bottom end of the U-piece
23
, as shown in
FIGS. 1 and 2
. At this time, it shows the on-state. In case of overload of the conductive strip
3
, the press element
2
can't be automatically escaped since it is located by the U-piece
23
. In order to switch to the off-state shown in
FIGS. 3 and 4
, it should be manually done. Consequently, the conventional press type switch doesn't have the protection effect in case of overload.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide an overload protection device of a press type switch in which the conductive strip is deformable in the contrary direction for an electric disconnection in case of overload so that the safety in use is attainable.
It is another object of the present invention to provide an overload protection device of a press type switch which can be used as a conventional on/off switch at ordinary times.
BRIEF DESCRIPTION OF THE DRAWINGS
The accomplishment of this and other objects of the invention will become apparent from the following description and its accompanying drawings of which:
FIGS. 1 through 4
are schematic drawings of a conventional two-stage press type switch;
FIG. 5
is a perspective view of an applicable embodiment of the present invention;
FIG. 6
is a perspective exploded view of the partial structure of the applicable embodiment of the present invention;
FIG. 7
is a sectional view of the partial structure of the applicable embodiment of the present invention;
FIG. 8
is a section of the side view of the applicable embodiment of the present invention in off-state;
FIG. 9
is a section of the side view of the applicable embodiment of the present invention in on-state;
FIG. 10
is a perspective view of a conductive strip of the applicable embodiment of the present invention, showing a contact piece is downwards;
FIG. 11
is a perspective view of the conductive strip of the applicable embodiment of the present invention, showing a contact piece is upwards;
FIG. 12
is an enlarged view of part I in
FIG. 8
, showing the push-pull element is situated at position (A) of the slide groove;
FIG. 13
is another enlarged view of part I in
FIG. 8
, showing the push-pull element slides from position (A) downwards to the lowest position (A′) and is ready to slide upwards;
FIG. 14
is a further enlarged view of part I in
FIG. 8
, showing the push-pull element slides is situated at position (B) and ready to slide downwards to the position (B′) and then upwards to return to position (A);
FIG. 15
is a perspective view of part II of the slide groove in
FIG. 12
;
FIG. 16
is a side view of part II of the slide groove in
FIG. 12
;
FIG. 17
is a perspective exploded view of the push-pull element and its relevant elements of another applicable embodiment of the present invention;
FIG. 18
is a sectional view of the partial structure of another applicable embodiment of the present invention;
FIG. 19
is a schematic drawing of the slide groove of another applicable embodiment of the present invention; and
FIG. 20
is a partially enlarged view of part III in FIG.
19
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
First of all, referring to
FIGS. 5 through 8
, the press type switch in accordance with the present invention includes a main body
4
, at least two conductive plates
43
,
44
and a push-pull element
6
.
The main body
4
is formed as a hollow rectangular case. A press button
41
is installed at the top thereof, and a projection
411
is fitted to each of two sides of the press button
41
and slidable up and down in a longitudinal groove
42
of the main body
4
. At least one resilient element
412
is disposed beneath the press button
41
.
A first conductive plate
43
has a conductive boss
431
while a second conductive plate
44
is connected to a conductive strip
5
to whose bottom a conductive nodule
51
opposite to the conductive boss
431
of the first conductive plate
43
is fitted.
The push-pull element
6
has a top bar
61
pivotably connected to a projecting ear
413
at inner rim of the press button
41
while the bottom end thereof is able to push and pull the free end of the conductive strip
5
, thereby forming a press type switch.
In addition, two slide grooves
7
,
7
′ are correspondingly arranged on the inner walls of the rear and front side of the main body
4
within the bouncing range of the free end of the conductive strip, as shown in FIGS.
7
and
7
′. Each of the slide grooves
7
,
7
′ is directed from the highest first locating position (A) downwards in a curved way to the lowest first turning position (A′), thereby forming a first slide rail
71
, and then directed upwards in a curved way to a second locating position B, thereby forming a second slide rail
72
. The second locating position (B) is situated lower than the first locating position (A) and at inner side thereof. And each of the slide grooves
7
,
7
′ is directed upwards in a curved way to a second turning position (B′) after intersecting the second slide rail
72
, thereby forming a third slide rail
73
, and then returns from the second turning position (B′) upwards to the first locating position A, thereby forming a fourth slide rail
74
so that the slide groove in 8-shape is formed. Moreover, a stepped drop side
711
,
721
,
722
,
731
,
732
,
741
is respectively formed at the connection and the cross positions between every two slide rails. The auxiliary slide groove
7
′ on inner wall of the front side of the main body
4
is the same in shape to the slide groove
7
on inner wall of the rear side thereof. The auxiliary slide groove
7
′ is only used to balance the other end of a cross bar
62
so that it doesn't need the stepped drop sides.
Furthermore, the conductive strip
5
has a projecting tongue
52
at front end thereof while the push-pull element
6
has an inverted T-shaped cross bar
62
at bottom thereof. Both ends of the cross bar
62
are respectively installed in the slide grooves
7
,
7
′. Besides, a resilient piece
64
is used to exert an inward resilient force on the slide groove at rear side of the main body
4
. One end of the resilient piece
64
is hooked on a protrusion
63
at outer side of the push-pull element
6
while the other end thereof is hooked on the projecting ear
413
of the press button
41
or another objects, as shown in FIG.
7
.
Referring to
FIGS. 10 and 11
, the conductive strip
5
disclosed in U.S. Pat No. 5,760,672 is an alloy plate extended with a contacting plate
53
at center thereof. The aforementioned conductive nodule
51
is mounted on the tail of the contacting plate
53
. By means of the shrinking assembly of the tail of the conductive strip
5
to the second conductive plate
44
, the free end of the conductive strip
5
is wider than the positioning end thereof, thereby forming a dished conductive strip
5
without the help of an additional spring member for pushing or pulling the projecting tongue
52
at free end of the conductive strip
5
at ordinary temperature and having bi-directional switching functions while the conductive strip
5
is transformable (from the shape in
FIG. 10
to the shape in
FIG. 11
) in case of overload. Therefore, an open circuit is attained. The configuration of the conductive strip
5
has been detailed described in prior art so that no further description will be given hereinafter.
By means of the above-mentioned technical features, the functions of the present invention are described as follows:
Referring to
FIGS. 8 and 10
, when the front end of the conductive strip
5
is directed downwards and the contacting plate
53
is raised, the conductive nodule
51
at tail portion thereof is separated from the conductive boss
431
of the first conductive plate
43
in an open circuit. At this time, the press button
41
is situated at the highest position by means of an upward resilient force of the resilient element
412
. Meanwhile, the push-pull element
6
rises such that both ends of the bottom cross bar
62
are situated at the first locating position (A) of the slide grooves
7
,
7
′. Accordingly, the open circuit is attained. In order to attain a closed circuit, press the press button
41
downwards while the push-pull element
6
is movable downwards therewith. Since both ends of the bottom cross bar
62
of the push-pull element
6
, as shown in
FIG. 7
, are situated in the slide grooves
7
,
7
′ on inner walls of the front and rear side of the main body
4
, the cross bar
62
slides along the first slide rail
71
downwards. When the press button
41
is pressed to the bottom, the cross bar
62
is moved to the first turning position (A′). At this time, the press button
41
is bounced upward by the resilience of the resilient element
412
after releasing the press button
41
, thereby moving the push-pull element
6
upward, as shown in FIG.
13
. When the push-pull element
6
rises, the cross bar
62
between the front and rear slide grooves
7
,
7
′ pulls the projecting tongue
52
at front end of the conductive strip
5
upwards so that the conductive strip
5
is transformed upwards, as shown in
FIGS. 9 and 10
. The tail portion of the contacting plate
53
is directed downwards so that the conductive nodule
51
is in contact with the contacting plate
53
to create the closed circuit.
Again referring to
FIG. 13
, when the push-pull element
6
brings the conductive strip
5
to bounce upwards, the cross bar
62
slides along the second slide rail
72
upwards to the second locating position B, as shown in FIG.
14
. At this time, the push-pull element
6
has changed its position and is situated above the conductive strip
5
. This is very important. In a closed circuit, there are no other blocking objects beneath the conductive strip
5
. In case of overload, the conductive strip
5
is transformable in the opposite direction into a convex shape by means of the shrinking assembly of the alloy plate, thereby creating an open circuit for ensuring the safety of the users.
Referring to
FIG. 14
, in case of no overload, the conductive strip
5
is situated at the position of the close circuit. In order to attain the open circuit, press the press button
41
so that the cross bar
62
at bottom of the push-pull element
6
slides along the third slide rail
73
downwards, thereby pushing the conductive strip
5
downwards. When the push-pull element
6
is pushed to the central position, it bounces to the off-state. Meanwhile, the cross bar
62
slides through the second slide rail
72
to fall into the second turning position B′. By means of the resilient force of the resilient element
412
, the press button
41
rises to bring the push-pull element
6
back to the first locating position A. Therefore, the original open circuit is attained again.
That the push-pull element
6
is slidable along the slide rails
71
,
72
,
73
,
74
in the slide groove
7
successively is completed on two pre-conditions. Firstly, a stepped drop side
711
,
721
,
722
,
731
,
732
,
741
is respectively formed at the connection and the cross positions between every two slide rails, as shown in
FIGS. 12
,
15
and
16
. Secondly, the cross bar
41
has always a resilient force in the direction of the rear slide groove
7
by means that the resilient piece
64
, as shown in
FIG. 7
, is fitted to the outer side of the push-pull element
6
. By means of these two features, the push-pull element
6
is able to slide along the preset path to reach the first locating position (A) and the second locating position B. Moreover, the push-pull element
6
can dodge the conductive strip
5
by means of the 8-shaped design of the curved crossed slide groove
7
so that the conductive strip
5
is freely transformable in case of overload without being blocked by any objects. Thus, the safety of the user can be ensured. In addition to the automatic disconnection function of the non-fuse switch, the present invention can be used as a conventional on/off switch at ordinary times. In other words, when the conductive strip
5
is transformed to the disconnection position in case of overload, the push-pull element
6
can be brought by the press button
41
from the second locating position (B) through the second turning position (B′) back to the first locating position A, as shown in FIG.
14
. The conductive strip
5
can be brought in the closed circuit by means of the action shown in FIG.
12
.
In order for the push-pull element
6
can directly return from the second locating position (B) to the first locating position (A) after the conductive strip
5
is transformed in case of overload, the cross bar
62
of the push-pull element
6
, as shown in
FIGS. 17 through 20
, is extended with a sloping arm
65
beneath while a fifth slide rail
75
is interposed between the first locating position (A) and the second locating position (B). In addition, the joint of the fifth slide rail
75
and the second locating position (B), as shown in
FIG. 20
, has a higher drop side
751
while the joint of the fifth slide rail
75
and the first locating position (A) has also a drop side
752
. Accordingly, when the conductive strip
5
is transformed in contrary direction in case of overload, the downward displacement of the projecting tongue
52
touches the sloping arm
65
so that the push-pull element
6
displaces itself outwards. Therefore, the push-pull element
6
passes over the drop side
751
to slide from the second locating position (B) to the first locating position A. This design enables the press button
41
after automatic switching in case of overload to return to the original off-state. This embodiment is more progressive than the aforementioned.
Many changes and modifications in the above-described embodiments of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.
Claims
- 1. An overload protection device of a press type switch comprising:a main body formed as a hollow rectangular case, a press button being installed at the top thereof, at least one resilient element being disposed beneath said press button; at least two conductive plates composed of a first and a second conductive plate, said first conductive plate having a conductive boss while said second conductive plate is connected to a conductive strip to whose bottom a conductive nodule opposite to said conductive boss of said first conductive plate is fitted; a push-pull element being pivotably connected to said press button while the bottom end thereof is able to push and pull the free end of said conductive strip, thereby forming a press type switch; wherein a slide groove consisting of a plurality of curved crossed slide rails is arranged on the inner wall of the rear side of said main body within the bouncing range of the free end of said conductive strip, and said slide groove is directed from the highest first locating position (A) downwards in a curved way to the lowest first turning position (A′), and then directed upwards in a curved way to a second locating position (B), and said second locating position (B) is situated lower than the first locating position (A), and then slide groove is directed upwards in a curved way to a second turning position (B′) after intersecting said second slide rail, and then returns from the second turning position (B′) upwards to the first locating position (A) so that said slide groove in 8-shape is formed, and a stepped drop side is respectively formed at the connection and the cross positions between every two slide rails; and wherein said push-pull element has a cross bar beneath, and the end thereof is disposed in said slide groove, and a resilient piece exerts a resilient force on said slide groove at rear side of said main body.
- 2. The overload protection device of a press type switch as claimed in claim 1, wherein said cross bar of said push-pull element is extended with a sloping arm beneath while another slide rail is interposed between the first locating position (A) and the second locating position (B), and wherein the joint of said slide rail and said second locating position (B) has a higher drop side while the joint of said slide rail and said first locating position (A) has also a drop side.
- 3. The overload protection device of a press type switch as claimed in claim 1, wherein a resilient piece is fitted to the outer side of said push-pull element, and one end of said resilient piece is hooked on a protrusion at outer side of said push-pull element while the other end thereof is hooked on a projecting ear of said press button.
US Referenced Citations (13)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2766007 |
Jan 1999 |
FR |