A plunger includes an upper base, a pressure ball under the upper base, a correlative tubular shaft extending vertically through the pressure ball, a handle pivotally connected with an upper end of the correlative tubular shaft, a connecting rod connects to the correlative shaft, and a lower end stopper threadably connected with the lower end of the connecting rod. The pressure ball can store air supplied by an air pump or compressor through an air inlet. The handle can be operated to let the air stored in the pressure ball flow through the correlative shaft, the connecting rod and the lower end stopper into a clogged pipe or drain for clearing passage with a large force of pressured air.

BACKGROUND OF THE INVENTION 
This invention relates to a plunger, particularly to one provided with an 
air pressure ball for storing air to be forcefully flowed into a clogged 
pipe or drain for clearing the clog. 
A known conventional plunger shown in FIG. 6, includes a sucking cup 10 
made of rubber connected with a long handle 20. In using it, the sucking 
cup 10 is placed on a mouth of a clogged pipe or drain of a toilet bowl as 
shown in FIG. 7, and is compressed and released alternately again and 
again so as to let it produce sucking force to turn over a clog and clear 
the passageway of the pipe or drain. However, this conventional has its 
sucking force quite limited, necessary to operate it laboriously to clear 
a clog and sometime cannot clear it due to small sucking force of the 
sucking cup 10, having not much practicability. 
SUMMARY 
The main object of the invention is to offer a plunger having a pressure 
ball under an upper base, a correlative tubular shaft extending vertically 
through the pressure ball and having its upper end combined with a handle 
pivotally connected with the upper base and its lower end connected with a 
connecting rod, and a lower end stopper threadably connected to the lower 
end of the connecting rod. Then air may be stored in the pressure ball by 
means of an air pump or compressor, and the handle is operated to pull up 
the correlative tubular shaft to let its lower end separate from the 
connecting rod so that the air stored in the pressure ball may forcefully 
flow out of the lower end stopper into clogged pipe for clearing the clog 
with a powerful force.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A first preferred embodiment of a plunger of the invention, as shown in 
FIGS. 1 and 2, includes an upper base 1, a long handle 2, a pressure ball 
3, a correlative tubular shaft 4, a connecting rod 5, and a lower end 
stopper 6 as main components combined together. 
The upper base 1 has a hollow chamber 11 formed in an intermediate portion 
with an upper open side, a threaded hole 12 formed in a projecting lower 
portion, a hole communicating the chamber 11 with the threaded hole 12 in 
the projecting lower portion, and an opening 14 formed at a right lower 
side of the chamber 11. 
The long handle 2 is pivotally connected in the hollow chamber 11 and 
located under the upper base 1, having a rear end protruding out of the 
opening 14 and a slot 21 formed in a front end. 
The pressure ball 3 is to store air therein, having male threads 31 and 32 
respectively in an upper and a lower end. The upper male threads 31 engage 
tightly with the threaded hole 12 of the upper base 1. The pressure ball 3 
further has an air inlet 33 laterally provided at a right side of an upper 
block formed integrally with the pressure ball 3, and a pressure gauge 34 
fixed at a left side of the upper block. 
The correlative tubular shaft 4 has a hole 41 in an upper end for a pin 42 
to pass laterally through and rest on two sides of the slot 21 of the 
handle 2 after the shaft 4 protrudes up through the slot 21, as shown in 
FIG. 3. Further, a coil spring 43 is fitted around an upper portion of the 
correlative shaft 4. The shaft 4 is further provided with male threads 44 
formed in a lower end. A cone-shaped stopper 45 is provided to have female 
threads 451 for male threads 44 of the shaft 4 to engage tightly after the 
shaft 4 extends vertically down through the pressure ball 3. 
The connecting rod 5 has female threads 51 formed in an upper end to engage 
the male threads 32 of the pressure ball 3. A short cone-shaped hole 52 
formed under the female threads 51, a long passageway 53 formed under the 
cone-shaped hole 52, and male threads 54 in a lower end. 
The lower end stopper 6 is cone-shaped, having female threads 61 in an 
upper end to engage the male threads 54 of the connecting rod 5. A center 
hole 62 under the female threads 61 communicating with the passageway 53 
of the connecting rod 5 for air to flow through down. 
In assembling, referring to FIGS. 2 and 3, firstly the handle 2 is 
pivotally combined with the upper base 1, and then the coil spring 43 is 
fitted around the correlative shaft 4, which is then inserted up through 
the slot 21 of the handle 2, with the pin 42 made to pass through the hole 
41, combining the correlative shaft 4 with the handle 2. Next, the lower 
end of the correlative shaft 4 is inserted vertically down in the pressure 
ball 3, with the male threads 44 protruding out of the pressure ball 3 and 
engaging with the female threads 451 of the upper end stopper 45, and with 
the male threads 31 engaging with the threaded hole 12 of the upper base 
1. After that, the male threads 32 of the pressure ball 3 is made to 
engage the female threads 51 of the connecting rod 5. Meanwhile, the 
cone-shaped upper stopper 45 just fits in the cone-shaped hole 52 of the 
connecting rod 5, and the male threads 54 engage tightly with the female 
threads 61 of the lower end stopper 6. Then the plunger is finished in 
assemblage. 
In using, referring to FIG. 4, the lower end stopper 6 is placed sealingly 
on the mouth of the clogged pipe or drain, and the air inlet 33 is 
connected to a compressor or an air pump. Then air is pumped through the 
air inlet 33 into the pressure ball 3, which then stores air therein. 
Meanwhile, the correlative shaft 4 is biased by the coil spring 43, with 
the upper stopper 45 forcefully pushing the cone-shaped hole 52 and 
hampering the air in the pressure ball 3 from flowing down. When a user 
checks the pressure gauge 34 and knows the pressure valve reaches the 
necessary one, the user pulls up the handle 2, forcing the upper stopper 
45 separate from the hole 52 to cause an aperture between the both, so 
that the air in the pressure ball 3 may flow through the passageway 53 of 
the connecting rod 5, the hole 62 of the lower end stopper 6, and then 
into the clogged pipe or drain. Thus, the clog may be forcefully moved to 
clear the passage of the pipe or drain. 
A second preferred embodiment of the plunger in the present invention has 
the same structure as the first preferred embodiment, except the 
correlative shaft 4, which has a threaded hole 46 formed in the upper end, 
as shown in FIG. 5, for a screw 47 with a ball-shaped head and threads 471 
to engage with. The diameter of the ball-shaped head has a larger diameter 
than the width of the slot 21 so that the screw 47 may rest on the slot 21 
after the upper end of the correlative shaft protrudes up through the slot 
21, securing the correlative shaft 4 with the handle 2. 
In general, the plunger in the invention utilizes air pressure obtained by 
an air pump or compressor to be stored in the pressure ball for clearing a 
clogged pipe or drain.