Adjustable flasher plug for multiple purposes

An adjustable flasher plug includes two load circuits such as light indicative circuits or decorative bulbs connected in series operatively contacting a left conducting pin of two pins connecting a power source, and a bimetallic strip jacketed in a heating coil operatively connecting two conducting pins of the power source, whereby upon the heating of the coil, the bimetallic strip will be bent to alternatively shift its contact from a load circuit to the other load circuit to form a simple, compact flasher device with adjustable alternative shift (flashing) frequency of the two load circuits.

BACKGROUND OF THE INVENTION 
A conventional electronic flasher contains a simple transistor circuit 
known as a multivibrator which produces a series of electric pulses at a 
precise rate, adapted for switching a miniature relay on and off. If an 
indicator light circuit or a strand of decorative bulbs is controlled by 
the relay contacts, and so the lamps or bulbs are switched on and off by 
the pulses from the multivibrator. 
However, one multivibrator is provided to switch a single relay with 
respect to a single light circuit. Multiple light circuits require plural 
multivibrators and relays to thereby increase their installation cost. 
The present inventor has found the defect of a conventional flasher and 
therefore invented an adjustable flasher plug. 
SUMMARY OF THE INVENTION 
The object of the present invention is to provide an adjustable flasher 
plug including: a plug casing, a pair of conducting pins for connecting a 
pair of terminals of a power source, a heating coil operatively connected 
across the two terminals, and a bimetallic strip jacketed within the 
heating coil having its upper strip end normally contacting a right load 
circuit and operatively contacting a left load circuit as heated by the 
coil so as to alternatively drive two load circuits, and having its lower 
strip end normally biasing a coil end to electrically contact a power 
source for heating coil and operatively bending outwardly to disconnect 
the power source for switching off the load circuit and the coil as heated 
by the coil, thereby resulting in a on-off control for the heating coil 
and having an alternative flasher effect either on the left or the right 
load circuit.

DETAILED DESCRIPTION 
As shown in the figures, the present invention comprises: a plug casing 1, 
a pair of conducting pins 2, 3 for connecting pair of terminals of power 
source, a heating coil 4, a bimetallic strip 5, a left load circuit 6 and 
a right load circuit 7. 
A left conducting pin 2 is formed with a fork portion 21 on its inner end, 
in which a lower cam 22 is rotatably provided therein to adjust a distance 
between the two extensions of the fork portion 21. The right conducting 
pin 3 is connected with a wire 31 for electrically connecting the right 
ends of the two load circuits 6, 7. 
The heating coil 4 is wound around a mica heating medium 40 jacketed on the 
bimetallic strip 5 and has its one coil end 41 formed as a contact plate 
made of phorsphor bronze and resiliently contacting the fork portion 21 of 
the left pin 2 as rightwardly biased by a lower strip end 51 of the 
bimetallic strip 5 and normally deviating from the pin 2 when not biased 
by strip 51, and has its other coil end 42 connected to right pin 3. The 
mica heating medium 40 can transfer heat of the coil 4 to the bimetallic 
strip 5, but can not conduct electricity due to its electric insulation 
property to thereby prevent from short-circuit between the coil 4 and the 
bimetallic strip 5. 
The bimetallic strip 5 is formed by laminating two flat metal strips with 
the right strip having higher heat expansion coeffeciency than that of the 
left strip. The lower strip end 51 normally biases the contactor plate 41 
of coil 4 rightwardly to contact the left pin 2, and operatively bends 
leftwardly without biasing the contactor plate 41 of coil 4 as heated by 
the coil 4, resulting in electric disconnection of coil 4 with the pin 2. 
The upper strip end 52 normally contacts a contact plate 71 formed on a 
left end of the right load circuit 7 and operatively bends leftwardly to 
contact a contact plate 61 formed on a left end of the left load circuit 6 
as heated by the coil 4. An upper cam 8 is rotatably provided between the 
two plates 61, 71 of the two circuits 6, 7 to adjust the distance between 
the two plates 61, 71. Either load circuit 6 or 7 can be applied as an 
indicator light circuit or a strand of decorative bulbs connected in 
series, or other flasher uses. 
When using the present invention, the pair of pins 2, 3 are inserted to an 
electric socket for leading power source therethrough. Since the contact 
plate 41 of the heating coil 4 is normally biased by the lower strip end 
51 of bimetallic strip 5 to electrically connect with the left pin 2, the 
coil 4 is powered as connected across the two pins 2, 3 to heat the 
bimetallic strip 5 as jacketed therein. 
The upper strip end 52 as being heated by the coil 4 will bend leftwardly 
towards the left contact plate 61 of the left load circuit 6 to change the 
power connection from the right circuit 7 to the left circuit 6. The lower 
strip end 51 will also bend leftwardly as being heated by the coil 4 at a 
slower rate than the bending movement of the upper strip end 52 to ensure 
the alternative contacting of the upper strip 52 with either left circuit 
6 or right circuit 7. The lower cam 22 made of insulating plastic 
materials serves to adjust the distance between the fork extensions 21, in 
terms of the resilient contacting of the fork portion 21 with the coil 
plate 41 and strip end 51. For instance, if the cam 22 is rotated to have 
its smaller diameter disposed between the two fork extensions 21, the 
resilient contacting of the coil plate 41, strip end 51 with the fork 21 
will be tighter to slow their deviation from the pin 2 after being heated. 
After the lower strip end 51 bends leftwardly to restore the contact plate 
41 of the coil 4 to disconnect the power supply, the coil 4 is no longer 
heated and the upper strip end 51 will be cooled down and recovered 
towards its original rightward direction as contacting the right circuit 
7. The lower strip end 51 will also be recovered towards the rightward 
direction, ready for next cycle of flashing operation. By the 
aforementioned alternative contactings of the right and left circuits 7, 6 
with the strip 5, a flasher action can be done or any other alternative 
shift operations of two load circuits can be accomplished. The upper cam 8 
can be used to adjust the distance between the two plates 61, 71, in terms 
of the speed of the alternative bending movement of the upper strip end 52 
or the alternative shift frequency (flashing frequency) of the two 
circuits 6, 7. 
Accordingly, the present invention provides a simple, compact construction, 
but with two load circuits which can be alternatively actuated to 
diversify their functions which, for instance, can be utilized to drive 
two strands of decorative bulbs with adjustable flashing operations.