Patent ID: 6979184

Claim:
A manual negative pressure pump device comprising: a suction cylinder being a long pumping cylinder; a handle connected to a rear end of the suction cylinder; a pull being a rod transversally inserted into the suction cylinder; a rear end of the pull being connected to a pull rod which is out of the suction cylinder; a piston installed in the suction cylinder and being fixed at a front end of the pull rod; and an expandable spring surrounding the pull rod and a front end of the expandable spring resisting against a piston and a rear end thereof resisting a handle; wherein by above components, a vacuum absorbing device is formed; characterized in that: a front end of the suction cylinder is a thread post with outer thread; the thread post central through hole and a plurality of small air holes around the through hole; the thread post is screwed with a nut of a joint; a valve and a drain-proof ring are installed between the joint and the thread post; the valve is a rubber washer and two end of the washer have respective pins; the two pins are inserted into a central through hole of the joint and the central through hole of the thread post; the central through holes of the joint and the thread post are retained with a predetermined distance.