1. Field of the Invention
The present invention relates to a multiple operation type electrical part suitable for use in operating, for example, a car stereo.
2. Description of the Related Art
A description will now be given of a conventional multiple operation type electrical part with reference to FIG. 30. The bearing 51 comprises an axial portion 51b, with a through hole 51a formed therein, and a flange 51c. A cylindrical outer shaft 52 is rotatably mounted in the through hole 51a of the bearing 51.
The cylindrical sleeve 53, fitted to the rear side of the outer shaft 52, is affixed to the outer shaft 52 by caulking the sleeve 53 from the outer side thereof.
The case 54, which is a zinc die-casting or the like, has a recess 54a having accommodated therein a self-returning coil spring 55. With the arm portion 55a retained by the side wall of the case 54, the coil spring 55 is mounted to the case 54.
The case 54, having the coil spring 55 mounted thereto, is disposed on the rear side of the flange 51c of the bearing 51. When the case 54 is disposed in this manner, the sleeve 53 is disposed so as to be placed within the wound portion 55b of the coil spring 55.
Clockwise or counterclockwise rotation of the outer shaft 52 causes rotation of the sleeve 53.
The rotation of the sleeve 53 causes movement of one of the arms 55a of the coil spring 55 in opposition to the resiliency of the arm 55a.
When the outer shaft 52 is released so that rotational force is longer applied thereto, the springy arm 55a, which has been moved, bumps into the side wall of the case 54 due to its resiliency, whereby the outer shaft 52 and the sleeve 53 rotate until they return to their original positions and stop there. Accordingly, the outer shaft 52 and the sleeve 53 are self-returning component parts capable of returning to their original positions by themselves.
A sliding member 57, formed of a springy metallic plate, is mounted to a rotary member 56, which is a molded product of synthetic resin. With the sleeve 53 fitted into a hole at the center portion of the rotary member 56, the rotary member 56 is mounted on the rear side of the case 54, so that it rotates as the sleeve 53 rotates.
The case 58, which is a molded product of synthetic resin, has a recess 58a. A contact member 59 is embedded in the case 58 so as to be exposed at the bottom portion of the recess 58a.
With the rotary member 56 accommodated in the recess 58a, the case 58 is disposed on the rear side of the case 54.
When the case 58 is disposed in this manner, the sliding member 57 can come into contact with and separate from the contact member 59. When the rotary member 56 rotates as a result of the rotation of the outer shaft 52, the sliding member 57 rotates in order to come into contact with or separate from the contact member 59, whereby a switching operation takes place.
The rotary member 56, having the sliding member 57 mounted thereto, and the case 58, having the contact member 59 mounted thereto, form a first rotary electrical part D4.
The inner shaft 60 is inserted into a hole of the outer shaft 52 in such a manner as to protrude from the rear side of the case 58, and is mounted in the hole so as to be rotatable and axially movable.
The case 61, which is a molded product of synthetic resin, has a bottom wall 61a, being a recessed portion, and a bumpy portion 61b, formed at the bottom wall 61a. With the inner shaft 60 inserted in a hole of the case 61, the case 61 is disposed on the rear side of the case 58.
The rotary member 62, which is a molded product of synthetic resin, has an axial portion 62a and a flange 62b. A clicking member 63, formed of a spring plate, is mounted at the front side of the flange 62b of the rotary member 62.
The case 64, which is a molded product of synthetic resin, has a recess 64a, at the center portion thereof, and a hole 64b, connected to the recess 64a. With the rotary member 62 accommodated in the recess 64a, the axial portion 62a of the rotary member 62 is fitted to the hole 64b, whereby the rotary member 62 is rotatably supported by the case 64.
With the rotary member 62 being inserted in the case 64 and the inner shaft 60 of the rotary member 62 being joined to the axial portion 62a of the rotary member 62 through splines, the case 64 is disposed on the rear side of the case 61.
When the case 64 is disposed in this manner, the clicking member 63 can engage and disengage the bumpy portion 61b of the case 61. Rotation of the inner shaft 60 causes rotation of the rotary member 62. This causes the clicking member 63 to engage and disengage the bumpy portion 61b in order to provide a tactile feel when the inner shaft 60 is rotated.
The case 61, the rotary member 62, having the clicking member 63 mounted thereto, and the case 64 form a click mechanism K.
The rotary member 65, which is a molded product of synthetic resin, has an axial portion 65a and a flange 65b, with a movable contact 66 being embedded in and mounted to the flange 65b.
The case 67, which is a molded product of synthetic resin, has a hole 67a and a recess 67b, with a sliding member 68, formed of a springy metallic plate, being embedded in and mounted to the case 67.
With the rotary member 65 being accommodated in the recess 67b, the axial portion 65a of the rotary member 65 is fitted into the hole 67a, whereby the rotary member 65 is rotatably supported by the case 67.
With the rotary member 65 being inserted in the case 67 and the inner shaft 60 being joined to the axial portion 65a of the rotary member 65 through splines, the case 67 is disposed on the rear side of the case 64.
When the case 67 is disposed on the rear side of the case 64, the sliding member 68 can come into contact with and separate from the movable contact 66. Rotation of the rotary member 65 as a result of the rotation of the inner shaft 60 causes the movable contact 66 to rotate and come into contact with and separate from the sliding member 68, whereby switching operations are performed.
The rotary member 65, to which the movable contact 66 is mounted, and the case 67, to which the sliding member 68 is mounted, form a second rotary electrical part D5.
With the inner shaft 60 being inserted in a hole formed in the center portion of an insulating plate 69, the insulating plate 69, formed of insulating material, is disposed on the rear side of the case 67.
A dislodgment preventing plate 70 is mounted to the inner shaft 60, projecting from the rear side of the insulating plate 69, in order to prevent the inner shaft 60 from being dislodged towards the front.
An actuating member 72 is mounted to the fixed member 71, being a molded product of synthetic resin. With the actuating member 62 being in contact with one end of the inner shaft 60, the fixed member 71 is fitted to the protrusion and the recess of the case 67 so as to be disposed on the rear side of the case 67.
The case 73, which is a molded product of synthetic resin, has a recess 73a and a bottom wall 73b, with contact members 74 and 75, exposed at the bottom wall 73b, being embedded in and mounted to the case 73.
The movable contact 76, formed of a springy metallic plate, is dish-like in shape and has a concavely formed center portion. It is accommodated in the recess 73a of the case 73. The center portion of the movable contact 76 is separated from the contact member 74, and the peripheral portions thereof are mounted to the contact member 75 so as to be normally in contact therewith.
With the fixed member 71 and the actuating member 72 being accommodated in the recess 73a, the case 73 is disposed on the rear side of the insulating plate 69.
When the case 73 is disposed in this manner, the center portion of the movable contact 76 comes into contact with the actuating member 72. The resiliency of the movable contact 76 causes the actuating member 72 and the inner shaft 60 to be normally pushed towards the front, so that the plate 70 is pushed against the insulating plate 69.
When the inner shaft 60 is pushed rearwards in the axial direction thereof, causing the actuating member 72 to move in the same direction, the center portion of the movable contact 76 is pushed in opposition to its resiliency, and comes into contact with the contact member 74. This renders the contact members 74 and 75 conductive, turning on a push switch S. When the inner shaft 60 is released, the resiliency of the movable contact 76 causes the actuating member 72 and the inner shaft 60 to return to their original positions. This causes the movable contact 76 to separate from the contact member 74, whereby the push switch S is turned off.
The case 73, to which the contact members 74 and 75 are mounted, and the movable contact 76 form the push switch S.
The cover 77, which is a molded product of synthetic resin, is disposed on the rear side of the case 73 in order to prevent entry of dust or the like into the case 73.
As described above, the bearing 51 and the cover 77 and the various component parts disposed therebetween are disposed successively on their corresponding component parts. These component parts are integrally mounted using a mounting plate (not shown).
A description will now be given of the operation of the multiple operation type electrical part having the above-described structure. When the outer shaft 52 is rotated clockwise or counterclockwise, the sleeve 53 and the rotary member 56 rotate at the same time. The sleeve 53 rotates in opposition to the resiliency of one of the arms 55b of the coil spring 55. The rotation of the rotary member 56 causes the sliding member 57, mounted to the rotary member 56, to rotate and come into contact with and separate from the contact member 59, whereby a switching operation is performed at the first rotary electrical part D4.
When the outer shaft 52 is released so that rotational force is no longer applied, the resiliency of the arm 55b, which has been moved, causes the sleeve 53 and the rotary member 56 to rotate back to their original positions, whereby the first rotary electrical part D4 returns to its original switching state. The rotary member 56 is a self-returning component part capable of returning to its original position by itself.
Clockwise or counterclockwise rotation of the inner shaft 60 causes rotation of the rotary member 62, joined to the inner shaft 60 through splines. This causes the clicking member 63, mounted to the rotary member 62, to engage and disengage the bumpy portion 61b of the case 61 in order to provide a tactile feel when the inner shaft 60 is rotated. This also causes the rotary member 65, joined to the inner shaft 60 through splines, to rotate. The rotation of the rotary member 65 causes the movable contact 66, provided at the rotary member 65, to rotate and come into contact with and separate from the sliding member 68, whereby a switching operation is performed at the second rotary electrical part D5.
When the inner shaft 60 is pushed rearward in the axial direction thereof, the actuating member 72 moves in the same direction to push the center portion of the movable contact 76 in opposition to the resiliency of the movable contact 76. This causes the center portion of the movable contact 76 to come into contact with the contact member 74, thereby rendering the contact members 74 and 75 of the push switch S conductive, and turning on the push switch S.
When the inner shaft 60 is released, the resiliency of the movable contact 76 causes the actuating member 72 and the inner shaft 60 to return to their original positions. This causes the movable contact 76 to separate from the contact member 74 and to turn off the push switch S.
Accordingly, the multiple operation type electrical part is operated in the above-described way.
The multiple operation type electrical part having the above-described structure is used in operating a car stereo. More specifically, the first rotary electrical part D4 is used for radio tuning. The second rotary electrical part D5 is used, for example, for volume or bass adjustments. The push switch S is used for switching, for example, volume or bass modes.
Since the various operations of the multiple operation type electrical part can be carried out at the operating portions concentrated at a particular area, the multiple operation type electrical part is used particularly in car stereos.
Dislodgment of the inner shaft 60 of the conventional multiple operation type electrical part is prevented by passing it through five cases, or cases 54, 58, 61, 64, and 67, and using the space in the case 73 at the rearmost portion of the multiple operation type electrical part. Therefore, the multiple operation type electrical part becomes very large in the axial direction thereof.
In addition, in order to move one of the arms 55b of the self-returning coil spring 55, a sleeve 53 needs to be formed separately of the rotary member 56, resulting in increased size of the multiple operation type electrical part.