Apparatus for temporarily shutting off electric power to an air conditioning compressor using a piston and microswitch

An apparatus for temporarily shutting off electric power to an air conditioning compressor of a vehicle is provided. The apparatus comprises a fixture having bent and upwardly extending sides that form a seat adapted to receive a portion of a tube. A piston is slidably received in the tube and has a rod securely attached to one end thereof. A linking rod is secured to the opposite side of the piston, and a spring plate of a microswitch is connected to the linking rod for turning the microswitch on and off. When the microswitch is turned off, an air conditioning compressor is no longer supplied with electric power. A central processing unit is connected to the microswitch and has a counter to count the shut off time of the electric power supplied to a compressor, and to resume the supply of electric power to the air conditioning compressor when a preset time has elapsed.

BACKGROUND OF THE INVENTION 
This invention relates to an apparatus for temporarily shutting off 
electrical power to the air conditioning compressor of a vehicle and more 
particularly to supplying more power to the vehicle drive system when the 
engine RPM momentarily jumps from a slow speed to a high speed, or when 
the engine is fully loaded, as when the vehicle is climbing uphill. 
Modern vehicles are designed to attract consumers and therefore have 
enhanced performance and luxury. The luxury accessories include such items 
as CD players, power seats, air bags, etc. Most of these accessories 
require electric power to operate, and therefore, a steady supply of 
electric power is required to power these accessories. However, when a 
vehicle is climbing uphill and fully loaded, or the vehicle is 
accelerating from a slow speed to a high speed, the electric power 
generated does not provide enough power for the engine to produce enough 
horsepower, and a power retardation will occur which causes gasoline 
combustion to be incomplete and thus carbons are collected on the spark 
plugs and smoke is expelled from the exhaust pipe. 
SUMMARY OF THE INVENTION 
It is the primary object of the present invention to provide an apparatus 
for temporarily shutting off electric power to the air conditioning 
compressor of a vehicle which thereby enables the electric power system of 
the vehicle to supply an adequate amount of electric power to the 
vehicle's engine for providing complete combustion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIGS. 1 through 6, there is illustrated a preferred 
embodiment of an apparatus for temporarily shutting off electric power to 
an air conditioning compressor during periods of heavy engine loading. The 
apparatus comprises a fixture 1 for holding a tube 2, the tube 2 having a 
larger-sized first section 21, a smaller-sized second section 22 and a 
shoulder 23 between the first section 21 and the second section 22. A 
piston 3 having a rod 31 extending from one side thereof is also provided, 
and a spring 4 having one end secured to one end of the piston 3 is 
disposed on the rod 31. A linking rod 5 is secured to and extends from the 
opposite side of the piston 3. A microswitch 6 having a spring plate 61 
extending outwardly therefrom and a housing 8 are further included in the 
apparatus. 
The fixture 1 may be formed by either metal or a temperature resistant 
plastic material, and is bent to have three surfaces: a bottom surface 11 
which is secured to the housing 8 by a fastener 124, and two side surfaces 
12 extending upwardly from respective sides of the bottom surface 11. The 
upwardly extending portions of the two side surfaces 12 are bent in 
several areas to form a pair of arcuate portions defining a seat 122 
adapted to receive the larger first section 21 of the tube 2 therein, and 
a pair of guiding rails 123 which are adapted to guide the tube 2 to slide 
therealong into the seat 122. A portion of each arcuate portion of the 
fixture 1 is bent inwardly to form a blocking end 121 which prevents the 
tube 2 from moving forward in the seat 122 and the piston 3 from extending 
beyond the tube 2, as shown in FIG. 3. The second section 22 of the tube 
is connected to an intake manifold of the vehicle's engine (not shown in 
the Figures). 
The piston 3 is sized to be received in the first section 21 of the tube 2 
in a telescopic manner and includes a rod 31 secured to one end thereof 
which will be inserted into the second section 22 of the tube 2 to guide 
the piston 3 to slide in the tube 2. A linking rod 5 is secured to the 
opposite end of the piston 3 having an aperture 51 formed in the distal 
end thereof and adapted for extension of the spring plate 61 therethrough. 
The spring 4 is secured to the end of the piston 3 where the rod 31 is 
secured, and rests in the first section 21 of the tube 2, with the distal 
end of the spring 4 engaged with the shoulder 23 to bias the piston 3. 
When the RPM of the engine of the vehicle is operated at a slow speed, the 
piston 3 will be sucked inwardly against the force of the spring 4 by 
engine vacuum, as shown in FIG. 2, and the microswitch 6 is then in a 
closed condition. When the RPM of the engine is changed from a slow speed 
to a high speed, momentarily, engine vacuum decreases and the piston 3 is 
displaced by the spring to extend outwardly, which pushes the spring plate 
61 outwardly, as shown in FIG. 4, and the microswitch 6 is then in an open 
condition. 
The microswitch 6, as shown in FIGS. 5 and 6, is connected to a central 
processing unit 7 which is an integrated circuit 71, and two transistors 
74 and 73. The IC 71 is connected to an oscillator 7' to form a counter. 
When the microswitch 6 is in an open status, the central processing unit 7 
will cut off the electric power output on line 72 to deactivate the air 
conditioning compressor 9. A counter is started by the central processing 
unit to count the cut off time, which is preset at 5 seconds. When the 
preset cut off time has been reached, the compressor 9 is activated again. 
Thus the engine load is reduced and electric power is fully supplied to 
the engine for the 5 second time period. In the meantime, if the RPM has 
returned to a slow speed, the piston 3 is again moved inwardly by engine 
vacuum, which activates the microswitch 6 and the compressor 9, 
simultaneously.