BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional front view of a switch according to this invention for showing its basic structure.
FIG. 2 is a sectional front view of a specific example of contact module.
FIG. 3 is a diagonal view of two contact modules arranged in parallel with portions removed.
FIG. 4 is a diagonal view of an example of switch with a portion removed.
FIG. 5 is a sectional side view of the switch of FIG. 4.
FIGS. 6A, 6B and 6C, together referred to as FIG. 6, are respectively a diagonal view of the whole of an example of contact module, a diagonal view of its plunger and its sectional side view.
FIGS. 7A, 7B and 7C, together referred to as FIG. 7, are respectively a diagonal view of the whole of another example of contact module, a diagonal view of its plunger and its sectional side view.
FIG. 8 is a diagonal view of an essential portion of an example of a switch with two contact modules of the kind shown in FIG. 6 and one contact module of the kind shown in FIG. 7.
FIG. 9 is a diagonal view of an essential portion of another example of a switch with three contact modules of the kind shown in FIG. 6, one of them being turned around in a backward direction.
FIGS. 10A, 10B and 10C, together referred to as FIG. 10, and FIGS. 11A, 11B and 11C, together referred to as FIG. 11, are still further examples of contact modules, FIGS. 10A and 11A being diagonal whole views, FIGS. 10B and 11B being diagonal views of their plungers and FIGS. 10C and 11C being their sectional side views.
FIG. 12 is a diagonal view of another switch embodying this invention formed with contact modules of the kinds shown in FIGS. 10 and 11.
FIG. 13 is a sectional front view of another switch using contact modules according to different embodiments of this invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the basic structure of a switch A embodying this invention, incorporating two contact modules M, an actuator 2 adapted to move like a see-saw and a push button 3 for operating the actuator 2 inside a switch case 1.
The two contact modules M have the same specifications, each having a normally closed contact mechanism 5 incorporated inside a module case 4. The contact mechanism 5 is comprised of a mutually facing pair of fixed terminals 6 disposed with a certain interval in between, a mobile piece 7 made of a conductive metal plate disposed opposite to the end parts of the fixed terminals 6 from below, a plunger 8 affixed to and supported by this mobile piece 7 and a spring 9 for biasing so as to slide the plunger 8 upward. Both fixed terminals 6 protrude downward from the bottom of the module case 4 so as to be connected to an external lead line. An operating part 8a extends from the plunger 8 and protrudes upward from the case.
The actuator 2 is axially supported by the switch case 1 so as to be able to swing like a seesaw around a fulcrum (supporting point) p at a position above and between the two contact modules M. The operating parts 8a protruding from the two contact modules M are positioned opposite to both end parts of the actuator 3. The actuator 3 is biased by a spiral spring 10 provided to the fulcrum p so as to swing back in a fixed direction. The biasing force of this spiral spring 10 is stronger than the force by the upwardly biasing spring force 9 such that, according to the illustrated example, the plunger 8 is pushed in on the left-hand side of the actuator 3 under the normal condition when the push button 3 is not being operated on such that the contact mechanism 5 of the contact module M on the left-hand side is opened, and the contact mechanism 5 of the contact module M on the right-hand side is closed when the plunger 8 moves upward by the biasing force.
If the push button 2 is operated upon and is pushed down, the actuator 3 is moved in the clockwise direction in the figure against the spring 9 in the contact module M on the right-hand side such that the contact mechanism 5 of the contact module M on the left-hand side is closed and the contact mechanism 5 of the contact module M on the right-hand side is opened.
In summary, the switch A for oppositely opening and closing two circuits is thus structured by using two contact modules M having the same specification with a normally closed contact.
With reference to FIG. 1, if a plurality of junction modules M are arranged in the direction perpendicular to the plane of the figure corresponding to each of the illustrated contact modules M and if the actuator 2 is made to extend in the same perpendicular direction, a switch capable of opening and closing three or more circuits can be obtained.
Some specific examples of the invention are described next with reference to drawings.
FIG. 2 is a front view of a specific example of the contact module M, and FIG. 3 is a diagonal view of two contact modules M arranged in parallel. The operating part 8a of the plunger 8 incorporated in this contact module M is at a position removed towards the back edge, and is protruding at a position removed backward from the center of the case.
The contact module M on the right-hand side of FIG. 3 is facing frontward, while that on the left-hand side is facing backward such that the operating part 8a of the contact module M on the right-hand side and that of the contact module M on the left-hand side are separated in the forward-backward direction. FIGS. 4 and 5 show a switch A for two circuits incorporating two contact modules M facing thus opposite to each other and arranged next to each other.
As shown in FIGS. 4 and 5, the actuator 2 incorporated inside the switch case 1 of this switch A has a larger width, the axial direction of its fulcrum p being the direction in which the contact modules M are arranged in parallel. As shown in FIG. 4, the farther (into the paper of the figure) end of the actuator 2 is opposite to the operating part 8a of the contact module M on the right-hand side and the near end of the actuator 2 is opposite to the operating part 8a of the contact module M on the left-hand side. As the actuator 2 is caused to oscillate backward by the strong spiral spring 10, the contact mechanism 5 of the contact module M on the right-hand side is opened if the push button 3 is not being pressed, and the contact mechanism 5 of the contact module M on the left-hand side is closed.
FIGS. 6A, 6B and 6C (together referred to as FIG. 6) and FIGS. 7A, 7B and 7C (together referred to as FIG. 7) show examples of contact module M(1) and M(2). FIGS. 6A and 7A are diagonal views of the whole of the contact modules M(1) and M(2), FIGS. 6B and 7B are diagonal views of their plungers 8(1) and 8(2), and FIGS. 6C and 7C are their sectional side views. The contact mechanisms 5 incorporated in these contact modules M(1) and M(2) are also formed to be generally closed, having a mobile piece 7 biased to be in contact with a pair of fixed terminals 6. All of their components other than the plunger 8 are the same between the two contact modules M(1) and M(2).
The plunger 8(1) of the contact module M(1) of FIG. 6 has its operating part 8a at a position displaced towards the front while the plunger 8(2) of the contact module M(2) of FIG. 7 has its operating part 8a at a position displaced backwards. It is therefore to be appreciated that two different kinds of contact modules M(1) and M(2) can be produced merely by using plungers of two different kinds 8(1) and 8(2) in module cases 4 of the same structure and that a switch A for opening and closing a plurality of circuits such as shown in FIGS. 8 and 9 can be easily structured by using these two kinds of contact modules M(1) and M(2).
FIG. 8 shows an example of switch that can thus be obtained by using one of the contact modules M(1) of the kind shown in FIG. 6 and two of the contact modules M(2) of the kind shown in FIG. 7 arranged in the axial direction of the supporting axis of the actuator 2 having an increased width in the same direction. This switch is adapted to close (or open) two circuits and open (or close) one circuit at the same time.
FIG. 9 shows another example of switch also adapted to close (or open) two circuits and open (or close) one circuit at the same time but by using three contact modules M(1) each having its operating part 8a displaced towards its front side with one of them (the one at the center in the illustrated example) turned around so as to face backward.
FIGS. 10A, 10B and 10C, together referred to as FIG. 10, and FIGS. 11A, 11B and 11C, together referred to as FIG. 11, show still further examples of contact modules M(3) and M(4). FIGS. 10A and 11A are diagonal whole views, FIGS. 10B and 11B are diagonal views of their plungers 8 and FIGS. 10C and 11C are their sectional side views. The contact mechanisms 5 incorporated in these contact modules M(3) and M(4) are also structured similarly to those for the contact modules M(1) and M(2) described above, forming as a normally closed mechanism with a mobile piece 7 biased so as to contact a pair of fixed terminals 6. In other words, components with the same specifications can also be used for these contact mechanisms 5.
The plungers 8 shown in FIGS. 10 and 11 have the same specifications. Each of their components is symmetrically formed in the forward-backward direction, except their operating parts 8a which are at shifted positions in the forward-backward direction. If the plunger 8 is contained such that its operating part 8a is at a position displaced in the forward direction, the contact module M(3) as shown in FIG. 10A with the operating part 8a displaced forward from the center of the module case 4 is obtained. If the plunger 8 is contained such that its operating part 8a is at a position displaced in the backward direction, the contact module M(4) as shown in FIG. 11A with the operating part 8a nearly at the center of the module case 4 is obtained.
It is thus possible to obtain a switch for opening and closing a plurality of circuits by using contact modules of these two different kinds M(3) and M(4), each obtained merely by selectively determining the direction in which the position of the plunger 8 of the same specification is incorporated. FIG. 12 shows an example of a switch thus obtained, having two contact modules M(4) of the kind with the operating part 8a nearly at the center of the module case 4 and one contact module M(3) of the kind with the operating part 8a displaced forward, arranged in the direction of the axis p of the fulcrum of the actuator 2 with an extended width, thus being adapted to open (or close) two circuits with the same open-closed characteristics and to close (or open) simultaneously one circuit with the opposite open-closed characteristic.
FIG. 13 shows another switch A using contact modules according to different embodiments of this invention, each incorporating a normally open contact mechanism 5 having a mobile piece 7 biased with a spring 9 in the direction of separating from the fixed terminals 6. Two contact modules M thus formed are arranged such that an actuator 2 adapted to undergo a seesaw-like motion operates on them oppositely for oppositely opening and closing two circuits. In the normally open contact mechanism 5, it is preferable to support the mobile piece 7 by the plunger 8 and to provide a back-up spring 11 for absorbing any displacement of the plunger 8 in excess of the stroke necessary for switching the contact condition by the backward displacement of the mobile piece 7.
The present invention is effectively applicable to switches of many different types such as limit switches, safety switches and door switches.
Patent Application
20080053809
