Rechargeable battery device

The present invention relates to an improved rechargeable battery device, particularly an improvement over the structure of the positive and negative terminals of a rechargeable battery, and of some parts of a charging device therefor. By adding a convex ring round the conventional terrace-shaped positive terminal of a rechargeable battery, which ring, formed integrally with said positive terminal, is for an elastic contactor from a charger to contact; and by forming an insulated central concave in the negative terminal to replace the conventional planar negative terminal, it is possible to avoid explosions caused by charging a non-rechargeable battery. Moreover, due to the above-said improvement, mixed use of rechargeable and non-rechargeable batteries is also made possible.

FIELD OF THE INVENTION 
This invention pertains to a rechargeable battery, and more particularly to 
electrodes for a rechargeable battery. 
BACKGROUND OF THE INVENTION 
In the prior art, there are many kinds of rechargeable batteries. Some use 
soldered positive and negative terminals, in which case the battery is, 
more often than not, sealed in a case which cannot be opened. So long as 
the rechargeable battery has come to the end of its life, since the used 
battery cannot be taken out, the device as a whole (for instance, an 
electric torch with a rechargeable battery) is good for nothing. Others 
have a terrace-shaped positive terminal (8 mm in diameter and 3 mm high) 
and a planar negative terminal (23 mm in diameter) in the same structure 
as the conventional non-rechargeable batteries (the R20 battery, for 
instance). 
To make the terminals of a rechargeable battery the same as those for a 
non-rechargeable battery has the advantage in that the device as a whole 
can continue to be used by replacing used batteries; besides, use of 
different kinds of batteries is also possible. However, if a rechargeable 
battery is mixed with a non-rechargeable one, or if the latter is charged 
by mistake, an explosion may possibly happen. 
SUMMARY OF THE INVENTION 
It is an object of this invention to provide an improved rechargeable 
battery, free from the above-said shortcomings; another object of the 
present invention is to provide structurally improved positive and 
negative terminals for a rechargeable battery, as well as an elastic 
contactor from a charger therefor, so that even if a non-rechargeable 
battery is mixed in, mixed use is still possible without any danger of 
explosion.

DESCRIPTION OF THE INVENTION 
To realize the object of this invention, the positive and negative 
terminals of a rechargeable battery are structurally improved so that the 
positive terminal 1 is made to consist of an integral piece having a 
cylindrical protrusion 11 in the centre and a concentric convex ring 12 
round the former, while the negative terminal is made to consist of a 
round piece 2 having a central concave, portion 13 10 mm in diameter, 
which concave portion 13 is covered by insulation material, so as to 
prevent conduction even if in contact with the positive terminal of a 
non-rechargeable battery. An additional elastic contactor 17 is provided 
with the charger 5 for contacting the convex ring 12 of the positive 
terminal 1, such that both non-rechargeable and rechargeable batteries can 
be used, and that even if a non-rechargeable battery is mixed in, charging 
could not be performed, thus avoiding a possible explosion. 
As above described, an improved rechargeable battery according to the 
present invention comprises a positive terminal 1 formed by an integral 
metal piece, which has a central terrace to contact an upper positive 
terminal 4 of a battery chamber leading to a load, and a convex ring 12 
surrounding round said central cylindrical protrusion 11 to contact an 
elastic contactor 17 from a charger 5; and further a negative terminal 2 
having an insulated concave portion 13, 10 mm in diameter (for the R20 
type battery), so that if a non-rechargeable battery's positive terminal 
touches upon said concave portion, no conduction occurs. In order that 
conventional rechargeable batteries can also be used in the present 
device, a separate plastic ring 12 can be glued onto the positive terminal 
11 end of the battery, as shown in FIG. 6, so that when fitted into the 
present device, said plastic ring 12 will push upon said elastic contactor 
17, for the latter to touch flange F of the battery chamber upper terminal 
4, thus making possible both charging and discharging. 
A device as above described can realize simultaneous charging of a battery 
and discharging through a load. A lower terminal 6 having the shape of a 
cylindrical cup with a surrounding rim is provided for the battery 
chamber, to match said negative terminal 2 of the battery, so that in use 
the rim of said terminal 6 is in touch with the ring portion of the 
battery's negative terminal 2 round its insulated central concave portion 
13. Said cylindrical cup lower terminal has a depth a little larger than 
that of the cylindrical protrusion 11 on a battery's positive end. 
Referring to FIG. 1, an improved rechargeable battery according to the 
present invention comprises a positive terminal 1 and a negative terminal 
2, said positive terminal 1 being formed by an integral piece having a 
central cylindrical protrusion 11 and a concentric convex ring 12, and 
said negative terminal 2 having a central concave portion 13 that is 
insulated through coating with insulation paint, such as resin, varnish, 
etc., or with an insulation paper label. It should be noted here that 
since the internal structure of the rechargeable battery (such as the 
flange F) is not altered, depicted in FIG. 1 are only the two terminals. 
In FIG. 2, three components are seen, namely, a bulb 9, a rechargeable 
battery 3, and a charger 5. Notwithstanding the fact that the three 
components may have very complicated circuits, for simplicity, a simple 
illustration is used to explain the working principle. The bulb 9 is a 
load. While the central terrace 11 of the battery's positive terminal 1 is 
in contact with the battery chamber's upper terminal 4, the convex ring 12 
is simultaneously in touch with an elastic contactor 17 from a charger 5. 
The battery chamber lower terminal 6 is hat-shaped and is in contact only 
on its brim with the conductive ring portion of said negative terminal 2. 
So as long as a switch 7 is closed, the bulb 9 will light; and so long as 
the plug of the charger 5 is connected to power, charging of the battery 
will occur. 
FIG. 3 is an alternative structure of the battery's negative terminal 2. 
Here, an insulation piece 14 is placed between two conductive pieces 15 
and 16, the former having a central opening. In this manner, the central 
portion of the battery's negative terminal 2 is also made to be insulated. 
Referring to FIGS. 1-3, if a non-rechargeable battery is put into the 
device, since its positive terminal 1 does not have a convex ring 12 round 
the central cylindrical protrusion 11, the elastic contactor 5-1 in FIG. 2 
cannot touch the positive terminal 4, thus making charging impossible, and 
avoiding a possible explosion. Now, if more than one battery in series are 
put into the device described in FIG. 2, nothing dangerous will happen. If 
the battery on top is a non-rechargeable one, as already described above, 
since no convex ring is provided on its positive terminal 1, contact 
between said positive terminal 1 and the elastic contactor 17 is 
impossible; if the one at the bottom of said series is non-rechargeable, 
since its positive terminal 1 is merely a central cylindrical protrusion 
11 which comes into touch with the central insulated portion 13 of the 
negative terminal 2 of the upper rechargeable battery, charging is also 
made impossible. Inasmuch, no matter how many non-rechargeable batteries 
in series are put inside, charging is always impossible. However, if a 
non-rechargeable battery is put above a rechargeable battery, the bulb 9 
can still be lit up. In this way, while explosion is completely avoided, 
mixed use of rechargeable and non-rechargeable batteries in series is 
still permitted. 
If, under certain circumstances, simultaneous charging and discharging are 
not allowed, the portion of the battery chamber's upper terminal 4 which 
is towards said contactor 17 can be cut off, as illustrated in FIG. 4. At 
the same time, as is seen in FIG. 5, a shunt switch 8 is used instead of 
the former switch 7. 
Another advantage of the present invention is as follows. With a device in 
the prior art, if the batteries are placed upside down, the bulb will 
still light; however, charging is absolutely impossible and may even 
destroy the device. In the present invention, if batteries (rechargeable 
or non-rechargeable) are put upside down, neither the bulb will light, nor 
will charging start. For if the upper battery is one according to the 
present invention, the insulated central portion 13 of its negative 
terminal 2 is in touch with the battery chamber's upper terminal 4; and if 
the lower one is a conventional battery, its positive terminal 1 cannot 
touch the bottom of the hat-shaped battery chamber's lower terminal. 
To sum up, the improvement according to the present invention does not have 
any high requirements for production facilities, and the cost is also very 
low. Apart from about 10% increase in blanking size for making the 
battery's positive terminal, provision on the battery's negative terminal 
of a concave portion is also quite easy; and where an insulation paper 
label is used, it can simultaneously serve as a quality control mark. 
Therefore, increase of cost is minimal, while the advantages are obvious 
that mischarging non-rechargeable batteries can be avoided, and mixing of 
a non-rechargeable battery can be checked out automatically. Moreover, 
troubles occurring because of batteries being placed upside down can also 
be avoided. All these make the rechargeable battery device of the present 
invention very easy and convenient and safe to use.