1. Field of the Invention
This invention relates to a power source connecting apparatus for an electronic appliance, and more specifically to a power source connecting apparatus for an electronic appliance which is constructed such that current leakage hardly occur and airtightness will not diminish.
2. Description of the Prior Art
Recently, there is a tendency toward increase in electric timepiece power consumption as the electronic timepiece functionality increases. For example, power consumption is considerably increased for those electronic timepieces provided with a personal computer function and those with television function. Accordingly they require a large-sized power source suited for them. On the other hand, watches are usually worn on a wrist during walking. Accordingly, they if large-sized, they are poor in appearance and obstructive, and tiring if heavy. Meanwhile, the frequent replacement of a small capacity battery requires opening of the battery lid in each time, hence resulting in troublesomeness. For these reasons, a variety of devices have been implemented for timepiece power sources. For example, JP-A-51-30773 discloses a timepiece incorporating a power source (secondary battery) of an electricity charging type.
FIG. 9 is a schematic explanatory view showing one example of the above-described electronic timepiece. FIG. 10 is a sectional view showing a power source connecting apparatus for the timepiece shown in FIG. 9. This electronic timepiece 500 is structured to have a charge terminal 502 provided on a side face of a main body case 501. The main body case 501 is fitted with a bushing 504 holding an electrode 503. The bushing 504 is slidable relative to the main body case 501. Meanwhile, a packing 505 for waterproofing is provided between the bushing 504 and the main body case 501. The bush 504 is urged toward the main body case 501 side by a spring member 506. A spring electrode 507 is arranged underneath the electrode 503. This spring electrode 507 is fixed inside the main body case 501, and has an end connected to a secondary battery 508. A charging power source (primary battery) 509 is connected with a socket 510. The socket 510 is projected with an electrode 511 at a front end thereof. The electrode 511 is electrically connected to the charging power source 509. Also, the socket 510 has a thread 512 cut at its end to be screwed to a internal thread 513 of the main body case 501.
First, if the socket 510 is screwed to the internal thread 513 in the main body case 501, the bushing 504 is pushed inside the main body case 501 while being urged by the spring member 506. Also, the electrode 511 on the socket 510 side comes in contact with the electrode 503 on the bushing 504 side. On the other hand, the electrode 503 is pressed to an inside of the main body case 501 due to the movement of the bushing 504, and the electrode 503 at its lower end comes into connection with the spring electrode 507. Due to this, electrical connection is obtained between the charging power source 509 and the secondary battery 508. In a usual use state, the charging power source 509 is removed. In this state, because the spring member 506 urges against the bushing 504, the packing 505 is sandwiched between a flange 504 of the bushing 504 and the main body case 501, keeping airtight the timepiece.
In the above-described electronic timepiece 500, the electrode 503 is left exposed. Due to this, if a conductive object is contacted therewith, the electrode 503 is put into connection with the secondary battery 508 thereby posing a problem of current leakage. Meanwhile, although the packing 505 is clamped to maintain airtightness by the urging force of the spring member 506, there has been a problem in that the airtightness decreases if the bushing 504 is externally pushed in.
Also, in the publication of JP-A-51-30773, there is a description on a charge terminal with a lid (FIG. 3 and FIG. 4 in the same publication). However, if a lid is provided, there is a problem in that removing the lid is troublesome. Also, the lid is a small part, resulting in a problem in of less The problems are not limited to the timepieces but they are common problems to electronic appliances having charge terminals.
Accordingly, this invention has been made in view of the above-described circumstances, and it is an object to provide a power source connecting apparatus which fulfills conditions of reduced current leakage, no decrease in airtightness, ease in power source connecting operation and no missing of parts, and an electronic appliance provided with this power source connecting apparatus.