1. Field of the Invention
The present invention is related to a seesaw switch and more particularly to a busbar contact of a seesaw switch which is embedded in a lens of an interior illumination lamp of a vehicle.
2. Description of the Related Art
In general, an interior illumination lamp is provided in a ceiling of a vehicle. As an interior illumination lamp of this type, there is known an interior illumination lamp which includes: a functional portion which is fixedly mounted in the ceiling of the vehicle in a state that a part thereof is exposed from an opening portion of a ceiling panel which is an interior material; and a design portion which is a cover lens fitted in the opening portion of the ceiling panel from a passenger compartment side so as to be assembled to the functional portion. The functional portion has a switch, and the design portion has a slidable switch knob. When the design portion is assembled to the functional portion, a slider of the switch is brought into engagement with an engagement portion made up of a recess portion formed in the switch knob, whereby the switch can be operated by sliding the switch knob (refer to PTL 1).
However, when the design portion is assembled to the functional portion, it is necessary that the slider of the switch is accurately positioned with the engagement portion of the switch knob, this making the assembling work complex.
PTL 2 discloses a switch as a means for solving the problem.
The switch disclosed by PTL 2 is a seesaw switch which is intended to realize an improvement in the assembling work. A vehicle interior illumination lamp described in PTL 2 includes: a light source; a functional portion having a switch which establishes or interrupts a supply of electric power to the light source; and a design portion having a cover lens which covers the functional portion and a switch knob which controls a switch lever. In addition, the switch knob is mounted in the design portion so as to oscillate. An oscillation axis of the switch lever and an oscillation axis of the switch knob coincide with each other in a state that the functional portion and the design portion are assembled together.
According to the seesaw switch of PTL 2, the oscillation axis of the switch lever and the oscillation axis of the switch knob coincide with each other in a state that the functional portion and the design portion are assembled together, and therefore, the assembling property of the seesaw switch is improved.
However, the seesaw switch of PTL 2 holds problems that a number of components is increased to increase the production costs and a number of assembling steps is increased.
[PTL 1] JP-A-2002-079879
[PTL 2] JP-A-2005-329884
It is therefore one advantageous aspect of the present invention to provide a seesaw switch which includes a decreased number of components so as to decrease the number of assembling steps to thereby improve the assembling property of the seesaw switch and which ensures a proper switch operation and allows the operator to feel a good switch operation feeling, and a contact thereof.
According to one advantage of the invention, there is provided a seesaw switch comprising:
Sloping angles of sloping surfaces of the end root portions may be smaller than a sloping angle of a sloping surface of the middle root portion.
The seesaw switch may be configured such that: the busbars include a first busbar and second busbar which contact individually the two contacts; the sloping surfaces of the end root portions of the first busbar are sloped at a first sloping angle from a root up to a halfway point and at a second sloping angle from the halfway point up to a peak of the end root portions; the sloping surfaces of the end root portions of the second busbar are sloped at a third sloping angle; and the third sloping angle is larger than the second sloping angle and is smaller than the first sloping angle.
The seesaw switch may be configured such that: at least one of a projection and a recess portion is formed on a sloping surface of at least one of the end root portions; at least one of a depression and a projecting portion is provided on each of the contacts; and the depression is configured to be brought into engagement with the projection and the projecting portion is configured to be brought into engagement with the recess portion, in a state where each of the contact stays still in one of the end root portions.
Thus, according to the first aspect of the invention, the switch can be made up of the contact and the wave-shaped portions of the busbars which are made up of the peaks and the roots, and therefore, the expensive balls and springs used in the conventional seesaw switches can be eliminated, this helping to reduce the production costs.
In addition, a proper switch operation feeling can be ensured by the spring property of the contact and the wave-shaped configuration of the busbars which comprises peaks and roots.
According to the second aspect of the invention, the sloping surfaces of the root portions at both the ends are more moderate than the sloping surfaces of the central root portion of the busbars, the switch operating load can be fluctuated, whereby the operating conditions of the switch can be altered.
According to the third aspect of the invention, the contact can be prevented from being forced out with the small load, whereby not only can the enlargement of the switch be prevented, but also the contact can be prevented from stopping in the midst of its movement.
According to the fourth aspect of the invention, the contact can be prevented further from being forced out with the small load.
An interior illumination lamp assembly 10 for a vehicle includes a lens 20 and a housing 40. Locking holes 20K in the lens 20 are brought into engagement with locking projections 40K on the housing 40 so that the lens 20 and the housing 40 are integrated together to make up the vehicle interior illumination lamp assembly 10.
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Firstly, these individual constituent elements will be described as follows.
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When the press fitting portion 60P of the contact 60 is press fitted into the press fitting grooves 30P in the two pillar-shaped accommodating portions 30S of the switch knob 30 from above in the way described above, the press fitting portion 60P of the contact 60 is accommodated in the switch knob 30 as
Then, when the switch knob 30 seesaws with respect to the shaft hole 30H in the switch knob 30, the two leg portions 60S projecting from the switch knob 30 swing about the shaft hole 30H.
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On the other hand, locking holes 40H (also, refer to
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Next, there will be described an assembling procedure for the vehicle interior illumination lamp assembly which employs the constituent components that have been described above.
In a step 1, the contact 60 is press fitted in the switch knob 30.
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In a step 2, the busbars 50 and the metal clips 70 are mounted in the housing 40.
The plurality of busbars 50 as
Further, the locking pieces 70H on the metal clips 70 are brought into engagement with the locking holes 40H in the clip locking portions 40C on the housing 40, whereby the metal clips 70 are assembled to the housing 40 as
In a step 3, the switch knobs 30 are assembled to the housing 40.
The switch knobs 30 (
In a step 4, the bulbs 80 are assembled to the housing 40.
The assemblies of the contacts 60 and the bulbs 80 are assembled in positions in the housing 40 which are indicated by arrows in
In a step 5, lens 20 is assembled to the housing 40.
Finally, the lens 20 is assembled to the housing 40 on which Step 4 has been completed. In order to assemble the lens 20 to the housing 40, the locking projections 40K on the housing 40 only have to be brought into engagement with the locking holes 20K in locking members 20L on the housing.
When all the components are mounted in the housing 40 in the way described above, the vehicle interior illumination lamp assembly 10 shown in
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1) Operation of Switch Knob 30L:
1-1) The switch knob 30M is a switch which turns off bulbs when doors of the vehicle are closed with a contact of the switch knob 30M situated in a DOOR position and turns on the bulbs when any of the doors is opened. However, in order to turn on the bulb B1 whether the doors are opened or closed with the contact of the switch knob 30M situated in the DOOR position, a contact of the switch knob 30L is situated in an ON position.
Then, the circuit is closed in the order of the battery, the bulb B1, the ON position, and the ground line, whereby the bulb B1 is turned on.
1-2) In addition, in order to turn off the bulb B1 which is turned on, the contact of the switch knob 30L is situated in an OFF position. Then, the circuit extending via the battery, the bulb B1, the OFF position, the ground line is not formed, whereby the bulb B1 is turned off.
2) Operation of Switch Knob 30R:
2-1) In order to turn on the bulb 2 whether the doors are opened or closed with the switch knob 30M situated in the DOOR position, a contact of the switch knob 30R is situated in an ON position.
Then, the circuit is closed in the order of the battery, the bulb B2, the ON position, and the ground line, whereby the bulb B2 is turned on.
2-2) In addition, in order to turn off the bulb B2 which is turned on, the contact of the switch knob 30R is situated in an OFF position. Then, the circuit extending via the battery, the bulb B1, the OFF position, the ground line is not formed, whereby the bulb B2 is turned off,
3) Operation of Switch Knob 30M:
3-1) A DOOR position of the switch knob 30M is connected to a courtesy line C. and this courtesy line C is connected to door-open/closed switches which are provided at portions of a vehicle body which face the doors. When the doors are closed, the door-open/closed switches are off, whereas when the door or the doors are opened, the corresponding door-open/closed switch or switches are on. Consequently, even with the switch knob 30L for the bulb B1 situated in the OFF position and with the switch knob 30R for the bulb B2 situated in the OFF position, when the switch knob 30M is situated in the DOOR position, since the DOOR position is connected to the courtesy line C, when the doors are closed, the door-open/closed switches are off, whereby the bulbs B1, B2 are kept turned off. When the door or doors are opened, the corresponding door-open/closed switch or switches are on, whereby the bulbs B1, B2 are turned on.
3-2) When the switch knob 30M is situated in an ON position, the bulbs which are turned off with the contacts situated in the OFF positions are turned on whether the doors are opened or closed.
3-3) When the switch knob 30M is situated in an OFF position, the bulbs with the contacts situated in the OFF positions are turned off whether the doors are opened or closed.
In Embodiment 1 of the present invention, contact areas of busbars 50A and 50B with which contacting portions 60A and 60B of a contact 60 are brought into contact are formed not into a straight line but into the shape of a wave made up of peaks and roots. Then, when the contacting portion 60A stays still at a rightmost root in the busbar 50A, the contacting portion 60B also stays still in a rightmost root in the busbar 50B. Likewise, when the contacting portion 60A stays still in a leftmost root in the busbar 50A, the contacting portion 60B also stays still in a leftmost root in the busbar 50B. Likewise, when the contacting portion 60A stays still in a middle root portion in the busbar 50A, the contacting portion 60B also stays still in a middle root portion in the busbar 50B.
When the contacting portion 60A slides down from a rightmost peak of the busbar 50A, the contacting portion 60B also slides down from a rightmost peak of the busbar 50B in the same direction as that the contacting portion 60A does. This holds true for the other peaks.
In this way, according to the invention, the switch can be made up of the contact 60 and the wave-shaped configurations of the busbars 50 which include the peaks and the roots. Therefore, the expensive balls and springs which are used in the conventional seesaw switch can be eliminated, thereby making it possible to decrease the production costs.
In addition, a good switching feeling can be ensured by the spring property of the contact 60 and the wave-shaped configurations of the busbars 50 which include the peaks and the roots.
Embodiment 2 of the present invention is characterized in that in busbars 50A, 50B with which contacting portions 60A and 60B of a contact 60 are brought into contact, a sloping angle of a middle root portion is made steep, whereas sloping angles of root portions at ends are made moderate.
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By adopting this configuration, when the contacting portions 60A2 and 60B2 move in directions Dout indicated by arrows in
Embodiment 3 of the present invention relates to a device to be made for two pairs of busbars and contacts.
In general, steep slopes of a root portion where a contact stays still can provide an advantage that the contact is prevented from moving easily with a low switch operating load. However, the depth of the root portion has to be increased so as to make the slopes steep, leading to a drawback that the size of a switch itself is enlarged. Thus, the decrease in switch operating load and the decrease in size of the switch are incompatible with each other.
However, when there are two pairs of busbars and contacts, those incompatible desires can be satisfied by Embodiment 3.
Slopes of left and right root portions 50B1 and 50B3 in the lower busbar 50B are steep (at a sloping angle θ1) from root bottoms up to halfway points along the slopes and are then moderate (at a sloping angle θ2) from the halfway points up to peaks of the slopes (θ1>θ2). In addition, slopes of root portions of the upper busbars 50A1, 50A3 are constant (at a sloping angle θ3. The three sloping angles are in a relationship of θ1>θ3>θ2.
In the root portions of the upper busbars 50A1, 50A2, 50A3, the slopes (the sloping angle θ3) of the root portions 50A1, 50A3 of the left and right busbars are made steeper than the slopes (the sloping angle θ2) of the root portions 50B1 and 50B3 of the left and right busbars of the lower busbar 50B. Thus, in this configuration, even in the event that the lower contact 60B1 (or 60B3) is about to stop while it is moving along the moderate sloping surface, the upper contacting portion 60A1 which is integral with the contact 60B1 is moving along the steep sloping surface, and hence, the upper contacting portion 60A1 entrains the contact 60B1 which is about to stop, whereby the contact 60B1 is prevented from stopping in the middle of moving along the moderate sloping surface.
The slopes of the left and right root portions of the lower busbar 50B are steep (at the sloping angle θ1) up to the halfway points and are then moderate (at the sloping angle θ2) from the halfway points up to the peaks. Thus, the contact 60B1 (or 60B3) stays still at the bottom of the root portion whose slopes are steep, thereby making it possible to prevent the contact 60B1 from being easily forced out of the root portion. However, in the event that all the slopes of the root portions are made steep (at the sloping angle θ1) so as to prevent the contact from being forced thereout, the root bottoms have to lie deep in the root portions to ensure a long distance to the adjacent roots. However, this increases the size of the switch, and hence, this approach cannot be adopted. Consequently, the slopes have to be made moderate from the halfway point. However, with the moderate sloping surface, the problem of the contact stopping in the midst of its movement is caused on the contrary, and hence, this approach cannot also be adopted.
According to Embodiment 3, by adopting the relationship of θ1>θ2, the contact can be prevented from being forced out of the root portion and the enlargement of size of the switch can also be prevented. In addition, by adopting the relationship of θ3>θ2 proposed in Embodiment 3, the biggest drawback of the contact stopping in the midst of its movement which results from adopting the inclination angle θ2 can be prevented.
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Consequently, since in a contacting portion 60B which stays still in the root, the projections 50T are in engagement with the depressions 60T, and therefore, the contacting portion 60B can be prevented from being forced out easily with a small load.
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Consequently, since in the contacting portion 60B which stays still in the root, the projections 60Q are in engagement with the recess portions 50Q, and therefore, the contacting portion 60B can be prevented from being forced out easily with a small load. A seesaw switch according to the present invention can decrease number of components so as to decrease a number of assembling steps to thereby improve the assembling property of the seesaw switch, and ensures a proper switch operation and allows the operator to feel a good switch operation feeling.
Number | Date | Country | Kind |
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2010-293089 | Dec 2010 | JP | national |
This application is a continuation of PCT application No. PCT/JP2011/080601, which was filed on Dec. 28, 2011 based on Japanese Patent Application (No. 2010-293089) filed on Dec. 28, 2010, the contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP2011/080601 | Dec 2011 | US |
Child | 13904462 | US |