Fluid handling – With repair – tapping – assembly – or disassembly means – Tapping a pipe – keg – or apertured tank under pressure
Reexamination Certificate
1998-11-19
2002-10-29
Walton, George L. (Department: 3753)
Fluid handling
With repair, tapping, assembly, or disassembly means
Tapping a pipe, keg, or apertured tank under pressure
C030S094000, C137S015140, C137S315410, C251S327000, C251S328000, C251S329000
Reexamination Certificate
active
06470907
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an existing pipe cut-off method, and a valve insertion method for inserting a valve in a line without stopping passage of water or fluid, etc.
2. Description of Prior Arts
Conventionally, a valve insertion method for inserting a valve in a line without stopping passage of water, by which an existing pipe is cut off without stopping passage of water and a valve is inserted into the cut-off portion of the existing pipe in a line including the existing pipe, has been already publicly known.
FIG. 72
shows a sketch of a conventional method disclosed in Japanese Laid-Open Patent Publication Nos. 44167 of 1980, 83690 of 1981, 120886 of 1981, and 47089 of 1982.
The method illustrated in the drawing is such that cutting equipment
500
is fixed at an existing pipe
1
, the cutting equipment
500
and existing pipe
1
are enclosed and sealed up by a seal-up housing
501
, and the left and right blades
502
are rotated along the cutting equipment
500
in order to cut off the existing pipe
1
. Thereafter, a valve is inserted into a line
1
A instead of a cut-off section
10
of the existing pipe
1
by opening and closing an operation sluice valve
503
. In the prior art, since the cutting equipment
500
is accommodated in the seal-up housing
501
, the seal-up housing
501
is made large-scaled to resultantly expand the digging area, etc.
FIG. 73
shows a sketch of a prior method disclosed in U.S. Pat. No. 5,611,365 and International Laid-Open WO 97/31207.
With the method illustrated in the drawing, an existing pipe
1
is enclosed and sealed up by a seal-up housing
600
, a cutting tool
602
is fixed at and attached to the tip end of a gate valve
601
installed at the seal-up housing
600
, and the gate valve
601
is turned together with the seal-up housing
600
, wherein an existing pipe
1
is cut off by the cutting tool
602
. According to the prior arts, since the cutting tool
602
is turned by rotations of the seal-up housing
600
, it is not necessary that the seal-up mechanism for turning the cutting tool
602
is provided in a seal-up housing
600
. Therefore, the seal-up housing
600
can be small-sized.
However, with such conventional cut-off methods, a chip-like cutter
602
bites an existing pipe
1
. Therefore, in a housing of cutting into an existing pipe
1
made of cast iron or steel, the seal-up housing
600
must be turned many times, wherein it takes much time to cut off. Furthermore, there is a fear that rubber packing to seal between the seal-up housing
600
and existing pipe
1
is damaged.
FIG. 74
shows a sketch of a conventional cut-off method disclosed in U.S. Pat. Nos. 3,650,547, 3,703,906, and 3,735,775.
With the prior art shown in the drawing, an existing pipe
1
is enclosed and sealed up by a seal-up housing
700
, and after a cutting wheel
701
attached to the seal-up housing
700
is caused to bite the existing pipe
1
by a lead screw
702
, the cutting wheel
701
is turned together with the seal-up housing
700
, whereby the existing tube
1
is cut off.
With the cutting method, since the cutting wheel
701
has a smooth outer circumferential part, it is impossible to cut off an existing pipe
1
made of cast iron and steel.
FIG.
75
(
a
) and FIG.
75
(
b
) show views of a conventional method for inserting a valve in a line without stopping passage of water, which is disclosed in U.S. Pat. No. 3,948,282.
With the conventional method shown in these drawings, an existing pipe
1
shown in FIG.
75
(
a
) is enclosed and sealed up by a seal-up housing
800
. Subsequently, an operation sluice valve
801
is attached to the seal-up housing
800
. Thereafter, a circular hole
803
is drilled by using a hole saw
802
in compliance with an already known method. After the drilling is completed,, as shown in FIG.
75
(
b
), a valve body
804
which is fitted into the drilled circular hole
803
is inserted therein.
With the conventional valve inserting method, since the hole
803
which has roughly the same diameter as the inner diameter of the existing pipe
1
is provided, the seal-up housing
800
shown in FIG.
75
(
a
) is made longer in the axial direction S and is made large-sized.
Furthermore, with the conventional inserting method, since hydraulic pressure is given to the valve body
804
shown in FIG.
75
(
b
) with respect to a large area equivalent to the circular hole, the diameter of the valve rod
806
is unavoidably made large.
Still furthermore, with the conventional inserting method, the circumferential edge
805
of the hole
803
at the existing pipe
1
is made thin, and pressure resulting from the valve body
804
is applied to the circumferential edge
805
, wherein the existing pipe
1
is liable to be broken.
FIG.
76
(
a
) and FIG.
76
(
b
) show the outline of a conventional valve insertion method for inserting a valve in a line without stopping passage of water, which was disclosed in U.S. Pat. No. 4,516,598.
In the prior art shown in these drawings, the existing pipe
1
in FIG.
76
(
a
) is enclosed and sealed up by an seal-up housing
800
. At this time, a hole saw
802
and a valve body
804
are accommodated in advance in the seal-up housing
800
. Thereafter, a circular hole is drilled at the existing pipe
1
by the hole saw
802
. After the drilling is completed, the seal-up housing
800
is turned as shown by the arrow
850
in FIG.
76
(
a
). After that, a valve body
804
is inserted into the circular hole
803
in FIG.
76
(
b
).
FIG. 77
shows the outline of a conventional valve insertion method for inserting a valve in a line without stopping passage of water, which was disclosed in U.S. Pat. No. 1,989,768.
In the prior art shown in this drawing, the existing pipe
1
in
FIG. 77
is enclosed and sealed up by a seal-up housing
501
. At this time, cutting equipment
500
and a sluice valve
510
are accommodated in advance in the seal-up housing
501
. After the cutting equipment
500
having a blade
502
cuts off and removes the existing pipe
1
, the sluice valve is inserted instead of the cutting equipment
500
.
The prior arts shown in FIG.
76
(
a
),
76
(
b
), and
FIG. 77
are able to quickly insert a valve after the cutting is completed. But with the prior arts shown in FIG.
76
(
a
),
76
(
b
), and
FIG. 77
, since it is necessary to accommodate a hole saw
802
or cutting equipment
500
, the size of which is equivalent to that of the valves
804
and
510
to be inserted, in the seal-up housing
800
or
501
, the seal-up housings
800
and
501
are obliged to be large-scaled.
SUMMARY OF THE INVENTION
The present invention has been developed to solve the problems inherent to the prior arts, and it is therefore a major object of the invention to provide an existing pipe cut-off method by which the existing pipe made of cast iron or steel can be cut off without causing its seal-up housing to turn many times.
It is another object of the invention to provide a method for inserting a valve in a line without stopping passage of water, in which the abovementioned method is employed.
It is still another object of the invention to provide a piping structure in which an existing pipe is scarcely damaged, an existing pipe slitting method by which the existing pipe can be slit to such a shape as the existing pipe is scarcely damaged, and a method for inserting a valve in a line without stopping passage of fluid.
In order to achieve the abovementioned main object, in a cut-off method according to the invention, a cutting tool, which is fixed at a rotatably supported cutter shaft and is provided with a plurality of blades, is accommodated in a seal-up housing in a state where the cutting tool is attached to the abovementioned seal-up housing while enclosing, in an airtight state, a part of an existing pipe by the abovementioned seal-up housing which is divided into plural sections in the circumferential direction of the existing pipe.
Subsequently, the abovementioned cutting tool is fed roughly in the cross direction of t
Homma Hideshige
Sato Toshiyuki
Yamashita Tamotsu
Yokoyama Gumpei
Sughrue & Mion, PLLC
SuIken Co., Ltd.
Walton George L.
LandOfFree
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