Suction valve of endoscope

1. A suction valve for an endoscope, wherein the endoscope comprises a first conduit and a second conduit, and the suction valve comprises a shaft, a pressing unit, and a holding seat;

wherein a first opening and a second opening are provided at a bottom and a sidewall of the shaft, respectively, the first opening communicating with the first conduit;

wherein the holding seat is sleeved in the shaft, and a middle portion of the shaft projects outward to form a ridge, the ridge being snap-fitted into the holding seat;

and wherein the pressing unit is connected to the shaft, the shaft being provided with a curved slide rail, the pressing unit being provided with a sliding ball at a position in contact with the curved slide rail, the pressing unit comprising a bump, a first slot being provided at a sidewall of the holding seat, the bump being snap-fitted with the first slot such that when the pressing unit is depressed, the bump moves in the first slot and the sliding ball slides along the curved slide rail to bring the shaft to rotate by a preset angle, such that the second opening communicates with the second conduit.

2. The suction valve for an endoscope according to claim 1 , wherein the pressing unit comprises a cap and a spring;

wherein one end of the spring abuts against the holding seat, and the other end of the spring is connected to the cap;

wherein a second slot having a size adapted to the shaft is provided inside the cap, and the sliding ball is disposed at an inner sidewall of the second slot;

and wherein the bump is disposed on an outer sidewall of the cap corresponding to the sliding ball.

3. The suction valve for an endoscope according to claim 2 , wherein the first slot has a length equal to a moving stroke of the second slot;

and wherein when being depressed, the cap compresses the spring, and the bump moves in the first slot, bringing the second slot to move till covering a connection between the holding seat and the shaft.

4. The suction valve for an endoscope according to claim 2 , wherein an equal number of bumps, first slots, sliding balls, and curved slide rails are provided.

5. The suction valve for an endoscope according to claim 4 , wherein two curved slide rails are provided, the two curved slide rails being arranged symmetrically about the center of the shaft.

6. The suction valve for an endoscope according to claim 2 , wherein two third openings are provided in the sidewall of the cap, the two third openings being oppositely arranged.

7. The suction valve for an endoscope according to claim 2 , wherein the suction valve comprises a sealing member, the sealing member being disposed between the spring and the holding seat and being tightly connected to the shaft.

8. The suction valve for an endoscope according to claim 1 , wherein a recessed groove having a size adapted to the bump is provided on an inner sidewall of the holding seat;

and wherein the recessed groove is arranged diagonally above the first slot, and an indentation having a width identical to that of the bump is provided between the recessed groove and the first slot.

9. The suction valve for an endoscope according to claim 1 , wherein the preset angle refers to an angle formed by a connecting line between one endpoint of the curved slide rail and the center of the shaft and a connecting line between the other endpoint of the curved slide rail and the center of the shaft, the present angle being 90°.

10. The suction valve for an endoscope according to claim 1 , further comprising a protective casing, the protective casing being sleeved with the holding seat.