Field of the Invention:
This invention deals with a rocker type switch for dual circuit having butt contacts
and defining overlapping circuit.
Background and Prior Art Description:
Figures 1a, 1b and 1c show an overall, an exploded and a sectional view of a
conventional switch with sliding contact design with overlapping circuit, respectively.
The conventional switch comprises of a knob sub-assembly, housing and a connector
sub-assembly.
As shown in figures 1d and 1e, the knob sub-assembly comprises a spring loaded
moving contact assembled within a recess provided in knob to make contact with
terminals (provided in the connector sub-assembly) at High or Low position. Spring
loaded ball is assembled from a lower side of knob and guided in a detent (provided in
the housing) for positioning of High and Low condition or vice-versa.
As shown in figures 1f and 1g, terminals are insert moulded in connector subassembly.
The shape and size of connector is decided with respect to mating
connector. All three terminals are separated. One terminal is for input and other two
terminals are for output.
As shown in figures 1h and 1i, the housing is used to assemble knob sub-assembly
and connector sub-assembly. A detent is provided in the housing for guiding of knob
sub-assembly in High or Low position.
Firstly, the knob sub-assembly is assembled with the housing to obtain a switch subassembly
as shown in figure 1j and therafter, the connector sub-assembly is
assembled with housing. A long pivot (shown in figure 1f & 1g) in the connector subassembly
helps in swivel angular movement of knob sub-assembly.
In High position, moving contact makes a contact with one output terminal and
common input terminal. In Low position, moving contact makes a contact with other
output terminal and common input terminal. Overlapping circuit is maintained while
changing position High to Low and vice-versa.
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As shown in figure 1k, angular walls are provided in the housing which act as stopper
for both positions, to restrict the over pressing of knob.
Due to sliding contact design, all the problems associated with it effects on life-cycle
of module are present in the above described conventional switch. Particularly, in this
design a single moving contact is used for both (High/ Low) position. Hence moving
contact is always in touch or rub with fixed contacts (either in High or Low position),
resulting wear and tear which effects on its durability (Life cycle reduced).
Object of the Invention:
Thus the object of the invention is to provide a rocker type switch for dual circuit
having butt contacts and defining overlapping circuit.
Brief Description of the Accompanying Drawings:
In order that the invention may be readily understood and put into practical effect,
reference will now be made to exemplary embodiments as illustrated with reference to
the accompanying drawings, where like reference numerals refer to identical or
functionally similar elements throughout the separate views. The figures together with
a detailed description below, are incorporated in and form part of the specification,
and serve to further illustrate the embodiments and explain various principles and
advantages, in accordance with the present invention where:
Figure 1a represents an overall view of a conventional switch with sliding contact
design with overlapping circuit;
Figure 1b represents an exploded view of a conventional switch with sliding contact
design with overlapping circuit;
Figure 1c represents a sectional view of a conventional switch with sliding contact
design with overlapping circuit;
Figure 1d represents perspective view of the knob sub-assembly of the conventional
switch;
Figure 1e represents a sectional view of the knob sub-assembly of the conventional
switch;
Figure 1f represents perspective view of the connector sub-assembly of the
conventional switch;
Figure 1g represents sectional view of the connector sub-assembly of the conventional
switch;
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Figure 1h represents perspective view of the housing of the conventional switch;
Figure 1i represents sectional view of the housing of the conventional switch;
Figure 1j represents perspective view of the conventional switch with the knob subassembly
assembled with the housing;
Figure 1k represents yet another sectional view of the conventional switch showing
the stoppers (which are formed in the housing);
Figure 2a represents an exploded view of the switch of the present invention with butt
type contact design with overlapping circuit;
Figure 2b represents perspective view of the knob sub-assembly of the switch of the
present invention;
Figure 2c represents a sectional view of the knob sub-assembly of the switch of the
present invention;
Figure 2d represents perspective view of the housing sub-assembly of the switch of
the present invention;
Figure 2e represents sectional view of the housing sub-assembly of the switch of the
present invention;
Figure 2f represents perspective view of the cover of the switch of the present
invention;
Figure 2g represents sectional view of the cover of the switch of the present invention;
Figure 2h represents perspective view of the switch of the present invention with the
knob sub-assembly assembled with the housing sub-assembly;
Figure 2i represents a perspective view of the switch of the present invention in an
assembled state;
Figure 2j represents a sectional view of the switch of the present invention showing
the operation of the stopper to restrict excessive movement of the knob;
Figure 3a represents a sectional view of the switch of the present invention at High
Position;
Figure 3b represents yet another sectional view of the switch of the present invention
at High Position;
Figure 4a represents a sectional view of the switch of the present invention at Low
Position;
Figure 4b represents yet another sectional view of the switch of the present invention
at Low Position; and
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Figure 5 represents the details of the contact making and overlapping zones realized
in a switch of the present invention.
Skilled artisans will appreciate that elements in the drawings are illustrated for
simplicity and have not necessarily been drawn to scale. For example, the dimensions
of some of the elements in the drawings may be exaggerated relative to other elements
to help to improve understanding of embodiments of the present invention.
Detailed description of the preferred embodiments
Before describing in detail embodiments that are in accordance with the present
invention, it should be observed that the device has been represented where
appropriate by conventional symbols in the drawings, showing only those specific
details that are pertinent to understanding the embodiments of the present invention so
as not to obscure the disclosure with details that will be readily apparent to those of
ordinary skill in the art having benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof, are intended to
cover a non-exclusive inclusion, such that a process, method that comprises a list of
steps does not include only those steps but may include other steps not expressly
listed or inherent to such process, method. Similarly, one or more elements in a
system or apparatus proceeded by “comprises… a” does not, without more
constraints, preclude the existence of other elements or additional elements in the
system or apparatus.
As shown in figure- 2a, two moving contacts are used separately for High and Low
position. Moving contacts are assembled in knob with torsion spring and pin. Torsion
spring presses moving contact to make its positive contact with respect to terminals in
operating condition and stopper provided in knob to restrict further movement of
moving contact in release condition. Pins are used for swivel angular movement of
moving contact.
Spring loaded ball/ plunger are assembled in knob and guided in detent provided in
housing similar to conventional switch.
As shown in figure- 2d, terminals are placed with respect to housing. All three
terminals are separated with each other. One terminal is for input signal and other two
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terminals are for output signal. Detent is provided in housing for guiding of knob subassembly
in High or Low position.
A cover is used to assemble knob sub-assembly with housing sub-assembly. A long
pivot in cover helps in swivel angular movement of knob (shown in figure- 2f).
Firstly, Knob sub-assembly (figure 2b and 2c) is assembled with Housing subassembly
(figure- 2d and 2e) and after that cover (figure- 2f and 2g) is assembled
from outside (shown in figure- 2h & 2i).
In High position shown in figures 3 a and 3b, one moving contact makes a contact
with one output terminal and common input terminal and in Low position shown in
figures 4a and 4b, the other moving contact makes a contact with other output
terminal and common input terminal. Overlapping circuit (as shown in figure 5) is
maintained while changing position High to Low and vice-versa.
Angular adjacent wall acting as stopper provided in housing for both position, to
restrict the over pressing of knob (shown in figure- 2j).
It can be said that in the new design, butt contact mechanism acts in operating
Dimmer module. When pressing High to Low or Low to High, moving contact butt on
two fixed terminals (one output and common input terminal) to make current path
with maintaining overlapping circuit.
The new modular switch contains 12 parts; 3 plastic parts and 9 metallic parts. In
plastic parts; It has 1 knob, 1 housing and 1 cover. In metallic parts; It has 3 fixed
terminals (two for output signal and one for input signal, where terminal for input
signal is common for both High and Low position), 2 moving contact (a & b), 2
torsion spring (c & d) and 2 pin (e & f) (shown in figure- 2a).
When switching Low to High or Low to High, one output terminal and common input
terminal gets connected separately by one moving contact (a or b) which houses in
Knob with torsion spring (c or d) and pin (e or f) (shown in figure 4a and 4b).
While changing position from High to Low or Low to High, overlapping circuit is
maintained (shown in figure- 5).
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High Durability: Due to overlapping circuit butt contact mechanism in new design of
Dimmer module, moving contact butt on fixed terminals. So that less friction between
terminals and moving contact, resulting less wear and tear as comparison to
conventional design, hence high durability.