Fluid handling – Processes – Cleaning – repairing – or assembling
Reexamination Certificate
2001-03-30
2001-10-30
Walton, George L. (Department: 3753)
Fluid handling
Processes
Cleaning, repairing, or assembling
C030S096000, C137S318000, C138S094000, C138S097000, C251S327000
Reexamination Certificate
active
06308726
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a valve insertion method without stopping passage of fluid, and a cutting tool.
2. Description of the Prior Art
A valve insertion method comprising drilling a hole in an already-installed pipe (or existing pipe) in a non-water-flow-stopping state, and inserting a valve in the hole thus cut in the already-installed pipe in a line including the same pipe has heretofore been known.
FIGS.
15
(
a
) and
15
(
b
) shows an outline of a conventional valve insertion method disclosed in U.S. Pat. No. 4,516,598.
According to the conventional techniques shown in these drawings, an already-installed pipe
1
is enclosed with a sealing case
800
. The sealing case
800
houses a hole saw
802
and a gate
804
therein in advance. A circular opening is then drilled in the already-installed pipe
1
with the hole saw
802
. After the opening is drilled, the sealing case
800
is turned as shown by arrows
850
in FIG.
15
(
a
), and the gate
804
is thereafter inserted into the circular opening
803
shown in FIG.
15
(
b
).
The conventional techniques of FIGS.
15
(
a
), (
b
) enable the insertion of the valve after the completion of the pipe cut-off operation to be carried out speedily. However, in the conventional techniques of FIGS.
15
(
a
), (
b
), the dimensions of the sealing case
800
increase because it is necessary that the hole saw
802
having the dimensions of which are equal to those of the gate
804
to be inserted is housed in the sealing case
800
.
FIG. 16
shows an outline of a conventional valve insertion method disclosed in U.S. Pat. No. 5,611,365 and International Patent Laid-Open W097/31207.
In the method shown in this drawing, an already-installed pipe
1
is enclosed with a sealing case
600
first. A gate
601
is then turned with the sealing case
600
to cut-off the already-installed pipe
1
with a cutting tool
602
fixed to a free end of the gate
601
. According to the conventional method described above, the dimensions of the sealing case
600
decrease because the cutting tool
602
has small dimensions. However, since the cutting tool
602
is fixed to the gate
601
, the leakage of water is not perfectly prevented. The already-installed pipe
1
is cut-off with a tip type cutting tool
602
. Therefore, in order to cut into an already-installed pipe
1
comprising a cast iron pipe or a steel pipe, the sealing case
600
has to be turned many times, so that it takes much time to cut-off the pipe.
U.S. Pat. 5,732,728 discloses a valve insertion method using an assembly provided with a rotary valve casing, a cutting assembly and a gate assembly. According to the conventional techniques, the gate assembly is fixed in place of the cutting assembly after a grooving operation is carried out, so that the dimensions of an apparatus decrease. However, in this prior art method, it is necessary to carry out an operation for replacing the cutting assembly with the gate assembly by opening and closing a seal means, so that the operations take much time.
SUMMARY OF THE INVENTION
Therefore, a primary object of the present invention is to provide a valve insertion method capable of carrying out valve insertion work speedily and miniaturizing a sealing case.
Another object of the present invention is to provide a cutting tool capable of improving a discharge rate of cutting chips producing in an operation for cutting an already-installed pipe (or existing pipe) in the valve insertion method.
One Aspect
In one aspect of embodiment of the valve insertion method according to the present invention, a valve assembly is inserted in an already-installed line by using a milling type cutting tool, the valve assembly and an operation valve so as to achieve these objects.
A worker prepares in advance the cutting tool, the valve assembly and the operation valve.
The cutting tool is supported so that it can be rotated freely around an axis set in an axial direction of the already-installed pipe, and it has cutting edges on its free end surface and outer circumferential surface.
The valve assembly has a valve casing forming a flow passage, a gate housed in the valve casing, and a valve spindle adapted to slide the gate in a direction which crosses the fluid passage at substantially right angles thereto.
The valve casing is provided with a first and second divisional cases separated from each other in the circumferential direction of the already-installed pipe.
Either one of these divisional cases is provided with a tool entering hole opened toward the center of the already-installed pipe.
The second divisional case is provided with a gate housing hole adapted to house the gate therein when the valve is opened, and enable the gate to move slidingly.
The gate housing hole and tool entering hole are provided in positions spaced from each other in the axial direction of the pipe.
The operation valve is fixed to the valve casing so that it can open and close the tool entering hole.
This valve insertion method has an assembling step, a drilling step, a grooving step, a tool takeout step and a transfer step which will be described below.
In the assembling step, a part of the already-installed pipe is enclosed air-tightly with the valve casing, and the gate and the cutting tool, which is independent of the gate, are housed in the valve casing with the gate and the cutting tool fixed thereto.
In the drilling step, the cutting tool is fed in the radial direction of the already-installed pipe as it is made to take cutting motions. The “cutting motions” referred to above means motions for cutting the already-installed pipe with the cutting tool rotated around the set axis mentioned above.
In the grooving step, the valve casing is turned in the circumferential direction of the already-installed pipe with the cutting motions kept being made. Owing to the turning of the valve casing in this step, the cutting tool is turned in the circumferential direction of the already-installed pipe, whereby the cutting tool is made to take feeding motions. Consequently, the already-installed pipe is cut in the whole of a circumferentially extending portion thereof with the cutting tool without producing a cut-off section. Thus, a cut groove is formed (cut) in the portion of the already-installed pipe, and extends in the direction of the range of the whole circumference thereof.
In the tool takeout step, the cutting tool is taken out from the valve casing via the operation valve after the completion of the grooving operation. Thereafter the operation valve is closed.
In the transfer step, the valve casing is transferred in the axial direction of the already-installed pipe after the completion of the grooving operation, whereby the gate is transferred to a position corresponding to that of the cut groove.
Another Aspect
In another aspect of embodiment of the valve insertion method according to the present invention, a valve assembly is inserted in an already-installed line by using a milling type cutting tool, a valve assembly and an operation valve.
A worker prepares in advance the cutting tool, the valve assembly and the operation valve.
The cutting tool is supported so that it can be rotated freely around an axis set in an axial direction of the already-installed pipe, and it has cutting edges on its free end surface and outer circumferential surface.
The valve assembly has a valve casing forming a flow passage, a gate housed in the valve casing, and a valve spindle adapted to slide the gate in a direction which crosses the fluid passage at substantially right angles thereto.
The valve casing is provided with a first and second divisional cases separated from each other in the circumferential direction of the already-installed pipe.
The second divisional case is provided with a gate housing hole, and a tool entering hole.
The gate housing hole is adapted to house the gate therein when the gate is opened, and is opened in the flow passage to enable the gate to move slidingly.
The tool entering hole is opened toward the center of the a
Sato Toshiyuki
Yamashita Tamotsu
Sughrue Mion Zinn Macpeak & Seas, PLLC
Suiken Co., Ltd.
Walton George L.
LandOfFree
Valve insertion method and cutting tool does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Valve insertion method and cutting tool, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Valve insertion method and cutting tool will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2554435