Branching unit for boring without stopping passage of fluid

A branching unit for boring without stopping passage of fluid, which is suitable for forming an opening at a pipe wall by boring a part of the pipe wall of an existing pipe using a drill machine having a hole saw to connect a branch pipe to the existing pipe, comprising:

• a sealing case including a first separate casing and a second separate casing separated in a circumferential direction of the existing pipe as well as surrounding a part of the existing pipe, and a branch pipe portion formed integrally with the first separate casing as well as projecting and branching off in a radial direction of the existing pipe;
• a valve body having an arc shape in cross section which opens and closes a branch hole of the branch pipe portion by rotating along the circumferential direction of the existing pipe between an inner circumferential surface of the sealing case and an outer circumferential surface of the existing pipe;
• a valve seat formed at the inner circumferential surface in the first separate casing, the valve body touching the valve seat in a valve closing state;
• and
• a rotation mechanism for rotating the valve body,
• wherein the rotation mechanism comprises an operation gear rotationally operated from an outside of the sealing case and a driven gear meshed with the operation gear, and
• the driven gear is rotated by the rotation of the operation gear in the circumferential direction, the valve body being reciprocated to open and close the branch hole,
• wherein the sealing case consists of two separate casings of the plural separate casings and the two separate casings are connected at connection portions at an inclined surface which inclines to a virtual flat surface orthogonal to an axis of the branch pipe portion,
• the two separate casings being connected at the inclined surface, a distance between the branch pipe portion and the connection portions in the first separate casing is larger at an upper portion than at a lower portion, and
• the operation gear is arranged at the upper portion.

A branching device for boring without stopping passage of fluid, which is suitable for forming an opening at a pipe wall by boring a part of the pipe wall of an existing pipe using a drill machine having a hole saw to connect a branch pipe to the existing pipe, comprising:

• a sealing case including plural numbers of separate casings separated in a circumferential direction of the existing pipe as well as surrounding a part of the existing pipe, and a branch pipe portion formed integrally with a first separate casing of the plural separate casings as well as projecting and branching off in a radial direction of the existing pipe;
• a valve body having an arc shape in cross section which opens and closes a branch hole of the branch pipe portion by rotating along the circumferential direction of the existing pipe between an inner circumferential surface of the sealing case and an outer circumferential surface of the existing pipe;
• a valve seat formed at the inner circumferential surface in the first separate casing, the valve body touching the valve seat in a valve closing state;
• and
• a rotation mechanism for rotating the valve body,
• wherein the valve body includes a concave surface which is curved along the outer circumferential surface of the existing pipe, a convex surface facing the branch hole in the valve closing position and being provided on an opposite side of the valve body than the concave surface, and an edge defining a spread of each of the concave surface and the convex surface,
• the rotation mechanism comprises an operation gear rotationally operated from an outside of the sealing case and a driven gear formed on the convex surface of the valve body without being formed on the concave surface and the edge,
• wherein the driven gear is meshed with the operation gear, being rotated by the rotation of the operation gear in the circumferential direction, the valve body being reciprocated to open and close the branch hole,
• a circumferential contact surface touching the valve seat in the convex surface, wherein the circumferential contact surface protrudes more than the surface of the driven gear in the radial direction of the existing pipe, and
• wherein the driven gear is positioned within an area surrounded by the circumferential contact surface without being positioned outside the area.