Note: Descriptions are shown in the official language in which they were submitted.
~o~37 9 ~ 9
Tllis invention relates to a flexible pipe connector
for pipe lines burried in the ground and especially suitable
for use in those regions of the pipe lines which are burried
in the ground surrounding building construction and tending
to occur discrepancies in alignment of the pipe lines.
Heretofore, it has been the common practice to
connect the opposite end flanges of pipes to be interconnected
with each o~cher by means of flexible pipe connectors each
inserted 'oetween two adjacent pipes to be interconnected.
However, when the ground becomes unevenly dipped, -for example,
that tends to locally displace the pipes to be interconnected
and induce discrepancies in alignment, provision must be
made of a number of short pipe connectors so as to absorb
and compensate for such amount of displacement mainly con-
sisting of the amount of dip of the ground.
An object of the invention, therefore, is to
provide a flexible pipe connector which makes use of de-
formable property of a rubber-like elastic body and partic-
ularly, utilizes shearing property thereof that tends to
readily deform it, which can absorb considerably large amount ~ ~
of displacement of pipes to be interconnected with a short ~-
pipe connector subjected to light load, and which can `
alleviate the load subjected from both ends of the pipe
connector to pipes to be interconnected whereby the pipe
line can be protected.
Another object of the invention is to provide
a flexible pipe connector which comprises yokes secured to `~
opposed pipes to be interconnected, free ends of the yokes
being slidably overlapped with each other and provided with ~
crossed elongate holes adapted to be guided by a pin, and -
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~37 9~9
which can permit pipes to be interconnected to displace in
directions such that discrepancies in alignment thereof are
compensatsd.
A further object of the invention is to provide
a flexible pipe connector which can detachably be secured to
pipes to be interconnected without necessitating any displace-
ment thereof.
A feature of the invention is the provision of
a flexible pipe connector comprising a rubber-like elastic
cylindrical body, at least two flat rings spaced apart from
each other in parallel and embedded in the rubber-like
cylindrical body, and fastening means for fastening those
flat rings which are arranged at the opposite ends of the
rubber-like elastic cylindrical body to pipes to be inter-
connected, the rubber-like elastic cylindrical body being
provided around outer peripheral surface thereof with `-
an outer circumferential groove formed between two adjacent ~`
flat rings and arcuate in section.
The invention will now be described in greater detail
with reference to the accompanying drawingsg wherein:
Fig. 1 is a longitudinal section of a flexible
pipe connector according to the invention;
Figs. 2, 3 and 4 are longitudinal sections of
different modified forms of a flexible pipe connector
according to the invention; and
Fig. 5 is a longitudinal section of a modified
form of the flexible pipe connector according to the invention
shown in Fig. 4.
Referring now to Fig. 1, the flexible pipe connector
1 illustrated therein is connected to the end flanges of ~`
- 3 -
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~3798g
pipes to be interconnected 2, 2 and generally formed of
metals.
The flexible pipe connector 1 is composed of
a rubber-like elastic cylindrical body 3 and at least two
(two in the embodiment shown) flat rings 4, 4 spaced apart
by a distance Q and arranged in parallel with each other,
the flat rings 4, 4 having a large rigidity and mainly formed
of metals. These two flat rings 4, 4 are embedded in the
rubber-like elastic cylindrical body 3. Each the flat rings
4, 4 is provided at its outer side with fastening means,
for example, a bolt 5, the bolt 5 being secured at its one
end to the flat ring 4 and having a free end extending through ~ ;
the flange of the pipes to be interconnected 2, 2 and
threadedly engaged with a nut. The rubber-like elastic
cylindrical body 3 is provided at its outer peripheral
surface between the opposed flat rings 4, 4 with an outer
circumferential groove 6 which is arcuate in section whose
radius is R.
In the above mentioned flexible pipe connector 1, `
it is preferable to make the total bonding force F acting ~
between the flat rings 4 and the rubber-like elastic ` -
cylindrical body 3 equal to the total strength P of that ~"
section of the rubber-like elastic cylindrical body 3 `~
which is the smallest in strength, that is, the total ~
strength P of the section of the base portion of the outer -
circumferential groove 6 so as to prevent the flexible pipe
connector 1 from being locally subjected to heavy load.
In order to provide such preferable flexible pipe -
connector 1, the radius R of the outer circumferential groove
6 can be defined as follows.
- 4 -
:; - . - : ,
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Let
Dl: Inner diameter of the pipe connector 1,
D2: Outer diameter of the pipe connector 1,
m : Depth of the outer circumferential groove 6,
- Q : Distance between the inside surfaces of the
opposed flat rings 4, 4, ;~
aA: Bonding force acting between the flat ring 2
and the rubber-like elastic cylindrical body
3, and
aB: Strength of the rubber like elastic cylindrical
hody 3,
then, as can be seen from the construction of the pipe
connector 1, the outer diameter of the flat ring 4 substan~
tially equal to the outer diameter D2 of the pipe connector
1 and the inner diameter of the flat ring 4 is substantially
equal to the inner diameter Dl of the pipe connector 1.
So, the total bonding force F acting between the
flat ring 4 and the rubber-like elastic cylindrical body 3 -~ ~-
is given by
F = ~D22-Dl2~A. :: .
In addition, the strength P of that section of ~:
the rubber-like elastic cylindrical body 3 which is the
smallest in strength, that is, the section of the base portion ; -:
of the outer circumferential groove 6 is given by : ~ :
,.. ~:: .
P = ~{(D 2 - 2m) 2 - Dl 2 } ~B. :~ :
- ,. .
By the above described reasons, it is preferable
- 5 -
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~,
37 9~
that F=P and m<~-, so that m is given by
m = ~ { D2-JD22~A)~ A)Dl2 }.
The radius of curvature R is given as follows.
(I) if m ~, then
R2 = (R-m)2~)2
~,
Hence
R = lz(g'm'm~
Alternatively,
~II) if m>~, then
~; :.
~. .
R = ~
,'' '-; .'
where ~ is a thickness of a lining coated on the flat ring 4.~
For example, let . ~ .;
Dl = 100 cm,
D2 = 120 cm,
Q = 10 cm~
~A = 100 Kg/cm2, and :
aB = 200 Kg/cm2 -.
then m = 5 cm and m = Q2' -~
Thus, if provision is made of an outer circum-
~ferential groove 6 whose radius of curvature R = 5 cm,
an excellent flexible pipe connector 1 which is not subjected
to any local load can be obtained
10379~9
n the embodiment shown in Fig. 1, as fastening ~:
means for fastening the pipe connector 1 to the pipes to
be interconnected 2, 2, provision is made o:E bolts 5, 5 one
end of which is secured to the respective flat rings 4, 4.
Alternatively, such ~astening means may comprise a pipe 7
made integral with each the flat plates 4 as shown in
Fig. 2. The pipe 7 is fitted around the pipes to be
interconnected 2, 2 and may be secured thereto with the
aid of a weld bead 8. ~-
In another embodiment according to the invention
shown in Fig. 3, provision is made of three parallel flat
plates 4, 4, 4 equally spaced apart ~rom each other by Q and
: embedded in the rubber-like elastic cylindrical body 3.
The present embodiment permits the pipe connector 1 to more : .
largely displaced. As fastening means for fastening the
pipe connector 1 to the pipes to be interconnected 2, 2, each `~
the two flat rings 4, 4 is provided with a tapped hole 9 ;
adapted to be threadedly engaged with a bolt (not shown) which
is extended through a flange integrally formed with the
respective pipes to be connected 2, 2.
In a further modified embodiment shown in Fig. 4,
the pipes to be connected 2, 2 are provided at their opposed `~
ends with flanges 17, 18. To the diametrically opposite
ends of the flanges 17, 18 are secured two pairs of yokes . ~
10, 11, free end of which being overlapped and slidably ` .
engaged with each other through a guide pin 14 extending `~ ~-
through an elongate hole 12 provided in the yoke 11 and
extending in a direction parallel with the axis of the pipes
to be interconnected 2, 2 and through an elongate hole 13
provided in the yoke 10 and extending in a direction of `
- 7 - :
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a tangent drawn perpendicular to the axis of the pipes to be
interconnected 2, 2. This pin-hole connection permits the
pipes to be interconnected 2, 2 to displace in the axial
direction as well as in the direction perpendicular thereto.
At least overlapped regions of respective yokes
10, 11 are made into two planes extending in the tangential
direction to the pipes to be interconnected 2, 2 and also in ~`~
the axial direction thereof so as to permit not only the ~ -
cylindrical body 3 to displace due to contraction and elonga- -
tion or bending thereof but also the pipes to be interconnected
2, 2 to displace in opposite directions shown by arrows ~
.
and
That is, even when discrepancies in alignment of ~ `
the pipes to be interconnected 2, 2 occur, the pin 14 serves `~-
- 15 to guide the yoke 10 or 11 along the tangentially extendingelongate hole 13. As a result, it is possible to absorb the
discrepancies in alignment of the pipes to be interconnected
2, 2 with no resistance subjected thereto. If the displace-
ment of the yoke 11 in the direction shown by the arrow ~
becomes excessively large, the pin 14 reaches to the upper ; ~-
end of the elongate hole 13 to permit no further displacement
of the yoke 11. So, the pipe connector 1 can effectively be
prevented from becoming broken.
The axially extending elongate hole 12 serves to
not only freely contract and elongate the pipe connector 1 `
in its axial direction but also exhibit its flexibility in
the case of bending it.
In order to insert the pipe connector 1 between
actual rigid type pipes to be interconnected 2, 2 in an
easily detachable manner, it is necessary to compress the
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rubber-like elastic cylindrical body 3 and reduce its length
in its axial direction. For this purpose, the pipes to be
interconnected 2, 2 are provided inside their respecti~e
flanges 17, 18 with ring-shaped plates 15, 16, respectively.
These ring-shaped plates 15, :L6 are aligned coaxially wi~h
the rubber-like elastic cylinclrical body 3 and have outer :
peripheral edge portions 21, 21 projected outwardly from the
pipes to be interconnected 2, 2 and provided at their dia-
metrically opposite positions with holes 19, 20.
In the case of inserting the pipe connector l
between the pipes to be interconnected 2, 2, the bolts 5~ 5 `~
whose respective inner ends are secured to the flat rings 4,
4 by welding or anchoring are inserted into the holes
provided in the flanges 17, 18 and the ring-shaped plates
15, 16 and then nuts are threadedly engaged with the bolts
5, 5.
In the case of removing the pipe connector 1 from ~ :
the pipes to be interconnected 2, 2, the nuts are removed : :-
from the bolts 5, 5 and then threaded bars 23, 24 are
extended through the holes 19, 20 provided in the peripheral
edge portions 21, 22 of the ring-shaped plates 15, 16. ` :~
Then, nuts are threadedly engaged with both ends of the bars
23, 24 so as to urge the ring-shaped plates 15, 16 against
the rubber-like elastic cylindrical body 3 thus compressing
it. Subsequently, the yokes lO, 11 are made loose and the
rubber-like elastic cylindrical body 3 is removed out of the -~
pipes to be interconnected 2, 2.
As stated hereinbefore, the flexible pipe connector
according to the invention has a number of advantages. In
the first place, the use of at least two flat rings embedded
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lW7~39
in a rubber-like elastic cylindrical body and the use of
fastening means provided at the ends of the flat rings and -
for selectively and interchangeably fastening the ends of
the flat rings to pipes to be interconnected make it possible
to utilize deformable property of the rubber-like elastic `
cylindrical body, particularly, utilize shearing property
thereof that tends to readily deform it. As a ~esult, short
pipe connectors burried in the ground can absorb considerably `
large amount of displacement of the pipes to be interconnected
which occurs when the ground becomes unevenly dipped or the
pipes to be interconnected are subjected to lar~e displacement ` ;
caused by difference between the nature of the ground. In -;;
this case, only a light load is subjected to both the ~ `~
rubber-like elastic cylindrical body and the pipes to be
interconnected, thereby protecting the pipe line from
becoming broken. Secondly, provision of an outer peripheral
groove which is arcuate in section between two adjacent flat
rings ensures an absence of concentration of stress exerted
upon the rubber-like elastic cylindrical body. Third, a
selection of the depth of the outer circumferential groove
such that the total bonding force acting between the fIat
rings and the rubber-like elastic cylindrical body is made
equal to the total strength of the section of the base
portion of the rubber-like elastic cylindrical body can
prevent the pipe connector from being subjected to local
load. Fourth, it is possible to improve the efficiency of ?
using materials for the rubber-like elastic cylindrical
body. Finally, the invention is capable of effectively
absorbing large displacement of the pipes to be interconnected,
particularly, displacement thereof caused by discrepancies
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1g3~ 9
in alignment, so that a pipe l.ine is effectively prevented
from being subjected to irrational force produced when the
ground becomes unevenly dipped.
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