Puncture needle device for ultrasonic endoscope

1. A puncture needle device detachably attached to an ultrasonic endo scope via a pipe sleeve which projects from said ultrasonic endo scope, said pipe sleeve including a non-circular-shaped collar, said puncture needle device comprising:

a cylindrical connecting body into which said pipe sleeve is inserted when said puncture needle device is attached to said ultrasonic endoscope, said cylindrical connecting body including an insertion limit portion which comes in contact with said pipe sleeve to prevent said pipe sleeve from being further inserted into said cylindrical connecting body when said pipe sleeve is inserted into said cylindrical connecting body to a predetermined position in an internal space of said cylindrical connecting body; and a non-circular-shaped collar receiving hole which is engaged with said collar and irrotatable relative to said collar when said pipe sleeve is inserted into said cylindrical connecting body to said predetermined position;

a flexible sheath which projects outwardly from said cylindrical connecting body through said internal space thereof and is inserted into an internal conduit of said ultrasonic endoscope through the inside of said pipe sleeve when said pipe sleeve is inserted into said internal space of said cylindrical connecting body;

a puncture needle inserted into said sheath to be movable therein; and

a lock member supported by said cylindrical connecting body to be movable between an unlocked position that allows said pipe sleeve to be inserted into said cylindrical connecting body to said predetermined position and to be removed from said cylindrical connecting body, and a locked position wherein said lock member contacts said collar of said pipe sleeve, that is inserted into said cylindrical connecting body to said predetermined position, to thereby prevent said collar from moving in a removal direction from said cylindrical connecting body.

2. The puncture needle device according to claim 1 , wherein said collar receiving hole and said collar are mutually the same in shape.

3. The puncture needle device according to claim 1 , further comprising a biaser, positioned between said lock member and said cylindrical connecting body, for biasing said lock member to move toward said locked position.

4. The puncture needle device according to claim 1 , wherein said pipe sleeve comprises a flange which projects from an outer periphery of said pipe sleeve to lie in a plane substantially orthogonal to an axis of said pipe sleeve, wherein said flange is provided closer to a body of said ultrasonic endoscope than said collar and comes into contact with said insertion limit portion when said pipe sleeve is inserted into said cylindrical connecting body to said predetermined position, and

wherein said insertion limit portion comprises a surface on said cylindrical connecting body which lies in a plane substantially orthogonal to an axis of said cylindrical connecting body.

5. The puncture needle device according to claim 1 , wherein said pipe sleeve comprises a flange which projects from an outer periphery of said pipe sleeve to lie in a plane substantially orthogonal to an axis of said pipe sleeve, wherein said flange is provided closer to a body of said ultrasonic endoscope than said collar and comes into contact with said insertion limit portion when said pipe sleeve is inserted into said cylindrical connecting body to said predetermined position, and

wherein said insertion limit portion comprises an elastic member made of an elastic material.

6. The puncture needle device according to claim 4 , wherein said flange comprises an annular flange, and

wherein said cylindrical connecting body comprises an annular surface with which a periphery of said annular flange comes in contact when said pipe sleeve is inserted into said cylindrical connecting body to said predetermined position.

7. The puncture needle device according to claim 5 , wherein said flange comprises an annular flange, and

wherein said cylindrical connecting body comprises an annular surface with which a periphery of said annular flange comes in contact when said pipe sleeve is inserted into said cylindrical connecting body to said predetermined position.

8. The puncture needle device according to claim 1 , wherein said lock member comprises at least one control knob positioned outside said cylindrical connecting body.

9. The puncture needle device according to claim 8 , wherein said lock member extends through said cylindrical connecting body, and

wherein two said control knobs are fixed at opposite ends of said lock member, respectively.

10. The puncture needle device according to claim 1 , wherein a surface in said collar receiving hole comprises a metal surface.

11. The puncture needle device according to claim 10 , wherein said surface in said collar receiving hole and said pipe sleeve are made of a same metallic material.

12. The puncture needle device according to claim 3 , wherein said biaser comprises at least one compression spring.

13. The puncture needle device according to claim 5 , wherein said elastic member comprises an elastic washer.

14. The puncture needle device according to claim 1 , wherein the shape of said collar is defined by a circular collar having radially opposite ends thereof cut off.