TUBE JOINT
[Technical Field]
[0001]
The present invention relates to a tube joint used to lay and connect a
deformable tube body, such as a hose or a tube having flexibility, formed of a soft
material such as synthetic resin or rubber.
[Background Art]
[0002]
As the tube joint of this type, there has been a tube joint including a joint body
including a cylindrical guide part internally fit in a connection tube, a tightening ring
concentrically externally fit in the guide part of the joint body while having a gap into
which a connection tube is inserted, a portion opposed to the guide part being capable of
contracting in diameter, and a cap nut externally fit to the tightening ring to contract
the diameter of the portion capable of contracting in diameter of the tightening ring, the
cap nut deforming the connection tube internally fit in the tightening ring (see, for
example, Patent Literature l).
In Patent Literature 1, the joint body includes, in the center part, a nut part
having a hexagonal shape in an outer surface. The tightening ring includes a brim
part having a hexagonal shape in an inner peripheral surface externally fit in the nut
part of the joint body and a cylindrical diameter contracting part provided on one end
face of the brim part to be externally fit in the guide part of the joint body while having
a predetermined gap. A screw groove, which screws with a screw groove provided on a
diameter contracting part outer peripheral surface of the tightening ring, is formed in
one side part of the inner peripheral surface of the cap nut. In a state in which the
connection tube is inserted into the gap between the diameter contracting part of the
tightening ring and the guide part of the joint body, the cap nut is rotated to be
screw-fed with respect to the diameter contracting part, whereby a taper surface of an
inner peripheral surface center part of the cap nut comes into contact with the distal
end of the diameter contracting part and the distal end part of the diameter contracting
part is contracted in diameter. As a result, an end part of the connection tube is
slip-stopped in a state in which the end part is fit in the guide part of the joint body and
the diameter contracting part of the tightening ring.
[Citation List]
[Patent Literature]

[0003]
[Patent Literature l] Japanese Patent Application Laid-open No. H02-062498
[Summary of Invention]
[Technical Problem]
[0004]
However, in such a conventional tube joint, the nut part of the joint body is fit
and inserted into the inner peripheral surface of the brim part of the tightening ring
and the nut part and the brim part are integrally attached. Therefore, the diameter
contracting part of the tightening ring easily tilts with respect to the guide part of the
joint body. Consequently, there is a problem in that the gap between the guide part
and the diameter contracting part becomes eccentric and it is difficult to insert the
connection tube.
Further, there is also a problem in that, even if the connection tube is held
between the guide part of the joint body and the diameter contracting part of the
tightening ring by tightening by the cap nut, if large force acts on the connection tube in
a slipping-off direction, the end part of the connection tube slips along the guide part of
the joint body and slips off together with the tightening ring and the cap nut.
When a deformable tube body such as a hose or a tube formed of a soft material
is used as the connection tube, a diameter contracting amount of the outer surface of the
tube body increases because of the tightening by the cap nut. Therefore, a deformation
amount of the diameter contracting part of the tightening ring also increases following
the increase in the diameter contracting amount. Consequently, if the tube body made
of synthetic resin, rubber, or the like is tightened by the diameter contracting part of the
tightening ring even once, the diameter contracting part is plastically deformed
exceeding anelastic deformation region. As a result, after the tube body is released
from the tube joint, even if it is attempted to connect the tube body again, the tube body
cannot be inserted by being obstructed by the plastically deformed diameter contracting
part. It is necessary to replace the diameter contracting part.
However, in the tube joint described in Patent Literature 1, in addition to the
diameter contracting part, the brim part externally fit in the nut part of the joint body is
integrally formed in the tightening ring. Therefore, when the tube body is connected
again, the entire tightening ring including the reusable brim part has to be replaced.
There is also a problem in that costs increase.
[0005]
The present invention has been devised to solve such problems and it is an

object of the present invention to prevent eccentricity of an insertion space of a tube
body.
[Solution to Problem]
[0006]
In order to achieve such an object, the present invention provides a tube joint
including: a joint body including a nipple provided along an insertion space of a
deformable tube body; a sleeve provided to be opposed to an outer peripheral surface of
the nipple in a radial direction across the insertion space of the tube body; and a
tightening member provided on an outer side of the sleeve and deforming a part of the
sleeve to be contracted in diameter toward the insertion space, wherein a plurality of
projections, which are in contact with the outer peripheral surface of the nipple, are
formed at a predetermined interval in a peripheral direction on an inner peripheral
surface of the sleeve.
[Advantageous Effects of Invention]
[0007]
In the present invention having the characteristics explained above, the
plurality of projections protruding at a predetermined interval in the peripheral
direction from the inner peripheral surface of the sleeve are respectively in contact with
the outer peripheral surface of the nipple. Therefore, the sleeve is untiltably
positioned with respect to the nipple.
Therefore, it is possible to prevent eccentricity of the insertion space of the tube
body.
As a result, compared with the conventional tube joint in which the nut part of
the joint body is fit and inserted into the brim part at the end of the tightening ring and
the nut part and the brim part are integrally attached, the insertion space of the tube
body has uniform width. Therefore, the tube joint exhibits excellent workability
because the tube body is easily inserted.
[Brief Description of Drawings]
[0008]
[Fig. l] Fig. 1 is an explanatory diagram showing the overall configuration of a tube
joint according to an embodiment of the present invention, wherein (a) is a longitudinal
sectional front view before connection and (b) is a longitudinal sectional front view after.
the connection.
[Fig. 2] Fig. 2 is a perspective view of the tube joint, wherein (a) shows a state after

assembly, (b) shows a state in which a tightening member and a part of a sleeve are
removed, and (c) shows a state in which the other parts of the sleeve are partially cut
out in Fig. 2(b).
[Fig. 3] Fig. 3 is an exploded perspective view of the tube joint, wherein (a) is an'
exploded perspective view of the entire tube joint and (b) is an exploded perspective
view of only the sleeve viewed from the opposite direction.
[Description of Embodiment]
[0009]
An embodiment of the present invention is explained in detail below with
reference to the drawings.
A tube joint A according to the embodiment of the present invention is a
connector in which, as shown in Fig. 1 to Fig. 3, a sleeve 20 is attached to a joint body 10,
which includes a nipple 11, to cover a part of the outer periphery of the joint body 10 and,
after a tube body B is inserted between the nipple 11 and the sleeve 20 in the axial
direction, the tube body B is tightened in the radial direction by a tightening member 30
from the outer side of the sleeve 20, whereby an inner surface B1 of the tube body B is
brought into press-contact with an outer peripheral surface 11a of the nipple 11 to
detachably lay and connect the tube body B.
Specifically, the tube joint A according to the embodiment of the present
invention includes, as main components, the joint body 10 including the nipple 11
provided along an insertion space S of the deformable tube body B having flexibility, the
sleeve 20 provided to be opposed to the outer peripheral surface 11a of the nipple 11 in
the radial direction across the insertion space S of the tube body B, and the tightening
member 30 provided on the outer side of the sleeve 20 to partially deform a part of the
sleeve 20 to be contracted in diameter toward the insertion space S.
Note that, as shown in Figs. 1(a) and (b), an inserting direction N of the tube
body B into the insertion space S is hereinafter referred to as "tube inserting direction
N". An opposite direction U of the tube inserting direction N is hereinafter referred to
as "tube slipping-off direction U".
[0010]
The joint body 10 is formed in a thick substantially cylindrical shape with a
rigid material, for example, metal such as brass or hard synthetic resin. Alternatively,
the joint body .10 is. formed in a.thin substantially cylindrical shape by pressing or .
otherwise molding a plate material or a tube material made of a rigid material
deformable by a tool such as stainless steel.

The nipple 11 having a cylindrical shape is formed on the distal end side of the
joint body 10. A protruding part 12 is formed on the base end side of the nipple 11.
The outer diameter of the nipple 11 is formed substantially the same as or
slightly larger or slightly smaller than the inner diameter of the tube body B explained
below. The outer peripheral surface 11a of the nipple 11 is formed smooth as a whole.
That is, the nipple 11 corresponds to "the guide part of the joint body" of Patent
Literature 1.
On the outer peripheral surface 11a of the nipple 11, in predetermined
positions in the axial direction of the outer peripheral surface 11a, it is desirable to
respectively form an annular protrusion 41 functioning as slip stopping means 40 for
regulating movement of the sleeve 20 explained below in the axial direction, an annular
groove 11b disposed adjacent to the tube slipping-off direction U side of the protrusion
41, and an uneven part for slip-stop 11c disposed to be opposed to the distal end side
inner peripheral surface of a diameter contracting member 22 of the sleeve 20 explained
below in the radial direction across the insertion space S of the tube body B. It is also
possible to form any one or two of the protrusion 41, the annular groove 11b, and the
uneven part for slip-stop 11c.
The protruding part 12 is formed in a diameter larger than the diameter of the
nipple 11. The protruding part 12 corresponds to the "nut part" of Patent Literature 1.
[0011]
As a specific example of the nipple 11, as shown in Figs. 2(a) to (c) and Figs.
3(a) and (b), a plurality of annular recessed parts and a plurality of annular projected
parts are alternately continuously unevenly formed in the radial direction as the
uneven part for slip-stop 11c only at the distal end part of the outer peripheral surface
11a. The external shape of the protruding part 12 is formed in a hexagonal shape.
As another example of the nipple 11, although not shown in the figures, it is
also possible to change the nipple 11 to, for example, form the nipple 11 in a bamboo
shoot shape in which annular recessed parts and annular projected parts alternately
continue in the axial direction over substantially the entire length of the outer
peripheral surface 11a of the nipple 11 or form the external shape of the protruding part
12 in other shapes such as a square shape.
Further on a depth side in the tube inserting direction N than the protruding
part 12 in the joint body 10, a connecting part 11d for connection to a tube connection
port(notshown in the figures) of another apparatus is continuously provided.
As a specific example of the connecting part 11d, when, for example, an
internal thread is cut on the inner peripheral surface of a tube connection port in

another apparatus connected to the tube joint A, an external thread corresponding to
the internal thread is cut. When an external thread is cut on the outer peripheral
surface of the tube connection port, an internal thread corresponding to the external
thread is cut.
[0012]
The sleeve 20 includes a fitting part 21a explained below for unrotatably fitting
with the protruding part 12 of the joint body 10 in the peripheral direction and a. screw
part 21b explained blow with which the tightening member 30 engages movably in the
axial direction. That is, the sleeve 20 corresponds to the "tightening ring" of Patent
Literature 1. As a difference from the "tightening ring", a plurality of projections 21d,
which are in contact with the outer peripheral surface 11a of the nipple 11, are formed
in the peripheral direction at a predetermined interval on the inner peripheral surface
of the sleeve 20.
The projections 21d are formed further on the depth side in the tube inserting
direction N than the insertion space S of the tube body B, which is defined and formed
between the inner peripheral surface of the diameter contracting member 22 and the
outer peripheral surface 11a of the nipple 11, to be adjacent to the insertion space S of
the tube body B. The inner end faces of the projections 21d are set in contact with the
outer peripheral surface 11a of the nipple 11, whereby the entire diameter contracting
member 22 is supported to be immovable in the radial direction.
As a specific example of the projections 21d, as shown in Figs. 2(a) to (c) and
Figs. 3(a) and (b), four projections 21d are respectively disposed at every equal interval
in the peripheral direction along the inner peripheral surface of the sleeve 20. The
inner end faces of the projections 21d are respectively set in contact with the outer
peripheral surface 11a of the nipple 11. In the case of the illustrated example, the
projections 21d are formed to protrude to the vicinity of the distal end part 21c on the
inner peripheral surface of a tubular member 21 explained below. The inner end faces
of the projections 21d are bumped against a protrusion 41 explained below formed on
the outer peripheral surface 11a of the nipple 11.
As another example, although not shown in the figures, it is also possible to
change the number, the shape, the disposition, and the like of the projections 21d, set
the inner end faces of the projections 21d in contact with the protrusion 41 and the
outer peripheral surface 11a of the nipple 11, and set the inner end faces of the
projections. 21d in contact with only the. outer peripheral surface 11a of the nipple 11
[0013]
Further, the sleeve 20 is desirably divided into the tubular member 21 that fits

with the protruding part 12 of the joint body 10 unrotatably in the peripheral direction
and with which the tightening member 30 engages movably in the axial direction and
the diameter contracting member 22 elastically deformable in the radial direction
deformed to be contracted in diameter toward the insertion space S of the tube body B
according to the axial direction movement of the tightening member 30. The tubular
member 21 and the diameter contracting member 22 are desirably joined and disposed
in the axial direction.
The tubular member 21 of the sleeve 20 is formed in a substantially cylindrical
shape with a rigid member such as hard synthetic resin and includes a fitting part 21a
that fits with the protruding part 12 of the joint body 10 unrotatably in the peripheral
direction and the screw part 21b with which the tightening member 30 screws movably
in the axial direction.
The external shape of the fitting part 21a is desirably formed in a shape such
as a hexagonal shape that engages with a tightening tool such as a wrench. That is,
the fitting part 21a corresponds to the "brim part" of Patent Literature 1.
The screw part 21b is formed along the outer peripheral surface of the tubular
member 21. The screw part 21b corresponds to the "screw groove" of Patent Literature
1.
In the distal end part 21c that joins with the diameter contracting member 22
explained below in the axial direction in the tubular member 21, it is desirable to form
an annular recessed part 21e in which a base end part 22c of the diameter contracting
member 22 fits to regulate swelling deformation of the diameter contracting member 22
during insertion of the tube body B.
[0014]
The diameter contracting member 22 of the sleeve 20 includes an elastically
deformed part 22a formed in a substantially cylindrical shape with an elastically
deformable material such as polyacetal resin or synthetic resin excellent in surface
slipperiness and heat resistance other than the polyacetal resin and elastically
deformed to be expanded in diameter and contracted in diameter in the radial direction
of the diameter contracting member 22. The inner diameter of the elastically deformed
part 22a is set substantially the same as or larger than the outer diameter of the tube
body B explained below during diameter expansion and set to be smaller than the outer
diameter of the tube body B during diameter contraction.
That is the diameter eontracting. member.22 is disposed such that the inner
peripheral surface thereof is opposed substantially in parallel to the outer peripheral
surface 11a of the nipple 11. Consequently, the insertion space S of the tube body B

explained, below is defined and formed in the tube inserting direction N and the tube
slipping-off direction U between the inner peripheral surface of the diameter
contracting member 22 and the outer peripheral surface 11a of the nipple 11.
Further, it is desirable that, on the distal end side inner peripheral surface of
the diameter contracting member 22, an uneven part for slip stop 22b opposed to the
uneven part for slip-stop lie of the outer peripheral surface 11a of the nipple 11 across
the insertion space S of the tube body B is formed and is set in contact with an outer
surface B2 in a connection end part Ba of the tube body B explained below. It is
desirable that, in the base end part 22c that joins with the tubular member 21 in the
diameter contracting member 22, a flange part 22d protruding toward the outer
peripheral surface 11a of the nipple 11 is integrally formed and the flange part 22d is
disposed to be opposed to, in the axial direction, a distal end face B3 of the connection
end part Ba of the tube body B explained below inserted toward the insertion space S.
[0015]
As a specific example of the diameter contracting member 22, as shown in Figs.
2(a) to (c) and Figs. 3(a) and (b), on at least on one side in the axial direction, specifically,
in a most portion excluding the base end part 22c in the tube inserting direction N, a
plurality of cutout parts 22e such as slots, slits, or recesses are respectively cut out and
formed at a predetermined interval in the peripheral direction as the elastically
deformed part 22a, whereby the diameter contracting member 22 is elastically deformed
to expand and contract in the radial direction and smoothly expanded in diameter or
contracted in diameter. Attachment to and detachment from the nipple 11 are
facilitated by forming a notch 22f over the entire length in the axial direction in the
diameter contracting member 22.
As another example, although not shown in the figure, it is also possible to
change the diameter contracting member 22 to a structure other than the illustrated
example, for example, respectively form the plurality of cutout parts 22e (such as slots,
slits, or recesses), which linearly extend in the axial direction, in the peripheral
direction in zigzag from both sides in the axial direction in the diameter contracting
member 22 or form a non-linearly extending cutout part such as a curved line.
[0016]
The tightening member 30 is formed with a rigid material such as hard
synthetic resin in a substantially cylindrical shape having an inner diameter larger
than the outer diameters of the tubular member 21 and the diameter contracting
member 22 of the sleeve 20. The tightening member 30 includes, on the inner
peripheral surface, a screw part 31 that screws with the screw part 21b of the tubular

member 21 and a taper-like pressing surface 32 that is opposed to and in contact with
the distal end side outer peripheral surface of the diameter contracting member 22.
That is, the tightening member 30 corresponds to the "cap nut" of Patent Literature 1.
Further, it is' desirable to form, on the outer peripheral surface of the
tightening member 30, a tool engaging part 33 that engages with a tightening tool such
as a wrench. It is desirable to provide, further in the tube slipping-off direction U than
the pressing surface 32 on the inner peripheral surface of the tightening member 30, a
reinforcing ring 34 made of a rigid material such as metal to be opposed to the
elastically deformed part 22a of the diameter contracting member 22 in the radial
direction. In particular, when the reinforcing ring 34 is integrally molded with the
tightening member 30 by insert molding, there is an advantage that the reinforcing ring
34 does not easily come off even if the temperature of the tightening member 30 rises.
[0017]
It is desirable that the slip stopping means 40 is provided over the outer
peripheral surface 11a of the nipple 11 and the sleeve 20, and the nipple 11 and the
sleeve 20 are engaged and positioned in the axial direction by the slip stopping means
40.
The slip stopping means 40 is a stopper that regulates movement in the tube
slipping-off direction U of the sleeve 20 with respect to the nipple 11. The stopper
functioning as the slip stopping means 40 includes a protrusion 41 formed on the outer
peripheral surface 11a of the nipple 11 and a locking piece 42 elastically deformable in
the radial direction that climbs over and fits with the protrusion 41 in the inserting
direction (the tube inserting direction) N of the tube body B and locks in the opposite
direction (the tube slipping-off direction) U of the inserting direction of the tube body B.
The sleeve 20 is inserted into the outer peripheral surface 11a of the nipple 11
in the tube inserting direction N, whereby the locking piece 42 climbs over the
protrusion 41. At the same time, at a point in time when the locking piece 42 climbs
over the protrusion 41, the distal end face of the locking piece 42 fits with the depth side
surface of the protrusion 41 to lock the protrusion 41 in the tube slipping-off direction U
[0018]
That is, in the locking piece 42, the inner diameter of the base end in the tube
inserting direction N of the locking piece 42 is set to be slightly larger than the outer
diameter of the protrusion 41. The locking piece 42 is gradually inclined to protrude
and approach the outer peripheral surface 11a of the nipple 11 from the base end in the.
tube inserting direction N toward the distal end in the tube slipping-off direction U of
the locking piece 42. The distal end in the tube slipping-off direction U of the locking

piece 42 is set to be substantially the same as or slightly smaller than the outer
diameter excluding the protrusion 41 in the nipple 11.
That is, the sleeve 20 is inserted in the tube inserting direction N along an
outer peripheral surface 11a of the nipple 11, whereby the base end in the tube inserting
direction N of the locking piece 42 passes the protrusion 41. An inclining portion
further on the distal end side than the base end bumps against the protrusion 41 to be
bent and deformed to the radial direction outer side and climbs over the protrusion 41.
Immediately after passing the protrusion 41, the inclining portion further on the distal
end side than the base end is bent and deformed to the radial direction inner side and
restored to the original shape. The distal end face of the locking piece 42 bumps
against the protrusion 41. The tubular member 21 of the sleeve 20 is positioned
immovably in the tube slipping-off direction U.
[0019]
In the example shown in Figs. 1(a) and (b) to Figs. 3(a) and (b), a plurality of
locking pieces 42 are formed at a predetermined interval at a plurality of locations in
the peripheral direction on the inner peripheral surface of the tubular member 21 of the
sleeve 20. Specifically, four locking pieces 42 are disposed at every equal interval in
the peripheral direction among four projections 21d on the inner peripheral surface of
the tubular member 21.
As another example, although not shown in the figure, it is also possible to
change the number, the shape, the disposition, and the like of the locking pieces 42.
[0020]
On the other hand, the tube body B is, for example, a hose or a tube deformably
molded to have flexibility with a soft material, for example, soft synthetic resin such as
vinyl chloride or silicone rubber or other kinds of rubber. The tube body B is desirably
flat on the inner surface B1 and the outer surface B2 at least at a connection end part
Ba.
As a specific example of the tube body B, a hose having a single layer structure
is used in the illustrated example.
As another example of the tube body B, although not shown in the figure, it is
also possible to use many kinds of tube bodies having different structures such as a
stacked hose (a blade hose) in which a plurality of or single blade (reinforcing thread) is
spirally embedded as an intermediate layer between a transparent or opaque outer
layer and a transparent or opaque Inner layer thereof a spiral reinforced hose
(VOHRAN hose) in which a belt-like reinforcing material rectangular in section or the
like made of synthetic resin or metal and a linear reinforcing material circular in

section or the like are spirally wound and integrated as an intermediate layer, and a
spiral reinforced hose in which a wire made of metal and a wire made of hard synthetic
resin are spirally embedded.
[0021]
A connection method of the tube body B by the tube joint A according to the
embodiment of the present invention is explained according to process order.
First, as shown in Fig. 1(a) and Figs. 2(b) and (c), the sleeve 20 is inserted along
the nipple 11 of the joint body 10 and the fitting part 21a of the sleeve 20 is fit with the
protruding part 12 of the joint body 10 unrotatably in the peripheral direction, whereby
the joint body 10 and the sleeve 20 are integrally attached.
Thereafter, as shown in Fig. 1(a) and Fig. 2(a), the tightening member 30 is put
over the outer side of the sleeve 20 and the screw part 31 of the tightening member 30 is
screwed in the screw part 21b of the sleeve 20. Consequently, the sleeve 20 and the
tightening member 30 are integrally assembled to the joint body 10.
[0022]
In this set state, as shown in Fig. 1(b), the connection end part Ba of the tube
body B is inserted toward the insertion space S between the inner peripheral surface of
the diameter contracting member 22 and the outer peripheral surface 11a of the nipple
11.
Subsequently, the tightening member 30 is screwed in and moved in the tube
inserting direction N. According to the movement of the tightening member 30, the
taper-like pressing surface 32 comes into contact with the distal end side outer
peripheral surface of the diameter contracting member 22, presses the diameter
contracting member 22 in the radial direction, and is compressed and deformed by the
elastically deformed part 22a. Consequently, the connection end part Ba of the tube
body B is held in the radial direction between the distal end. side inner peripheral
surface (the uneven part for slip-stop 22b) of the diameter contracting member 22 and
the distal end part (the uneven part for slip-stop 11c) of the outer peripheral surface 11a
of the nipple 11, compressed and deformed, and slip-stopped in the axial direction.
Thereafter, at a point in time when the screwing of the tightening member 30
ends, connection work of the tube body B is completed.
[0023]
With the tube joint A according to the embodiment of the present invention, the
plurality of projections 21d protruding at a predetermined interval in the peripheral
direction from the inner peripheral surface of the sleeve 20 are respectively in contact
with the outer peripheral surface 11a of the nipple 11. Therefore, the tubular member

21 of the sleeve 20 is untiltably positioned with respect to the nipple 11.
Therefore, it is possible to prevent eccentricity of the insertion space S of the
tube body B.
Asa result, since the insertion space S of the tube body B has uniform width,
the tube body B is easily inserted. The tube joint A exhibits excellent workability.
[0024]
In particular, it is desirable that the slip stopping means 40 that engages the
nipple 11 and the sleeve 20 in the axial direction is provided over the outer peripheral
surface 11a of the nipple 11 and the inner peripheral surface of the sleeve 20, and the
slip stopping means 40 includes the protrusion 41 formed on the outer peripheral
surface 11a of the nipple 11 and the locking piece 42 elastically deformable in the radial
direction that climbs over and fits with the protrusion 41 in the inserting direction N of
the tube body B and locks in the tube slipping-off direction U.
In this case, as the slip stopping means 40 provided over the outer peripheral
surface 11a of the nipple 11 and the sleeve 20, the locking piece 42 is elastically
deformed in the radial direction to climb over and fit with the protrusion 41, which is
formed on the outer peripheral surface 11a of the nipple 11, in the inserting direction N
and, at the same time, at a point in time when the locking piece 42 climbs over the
protrusion 41, the locking piece 42 locks in the tube slipping-off direction U and is
immovably locked.
Therefore, it is possible to position the sleeve 20 with respect to the nipple 11
immovably in the slipping-off direction of the tube body B.
As a result, compared with the conventional tube joint in which, when large
force acts on the connection tube in the slipping-off direction, the end part of the
connection tube slides along the guide part of the joint body and slips off together with
the tightening ring and the cap nut, it is possible to surely slip-stop the tubular member
21 of the sleeve 20, the tube body B, and the like and achieve improvement of
slipping-off strength.
Further, irrespective of what kind of a hard material such as metal the nipple
11 is made of and what kind of soft material such as synthetic resin the sleeve 20 is
made of, the distal end of the locking piece 42 is not scratched during the passage of the
protrusion 41. It is possible to attach the sleeve 20 to the nipple 11 without backlash in
the radial direction.
As in the illustrated example, when the plurality of locking pieces. 42. are
respectively disposed to be held in the peripheral direction among the projections 21d
disposed at a predetermined interval in the peripheral direction, it is easy to mold the

sleeve 20 with resin using a molding die. It is possible to achieve a reduction in
manufacturing costs.
[Example]
[0025]
An example of the present invention is explained with reference to the
drawings.
In this example, as shown in Figs. 1 to 3, the sleeve 20 is divided into the
tubular member 21 that fits with the protruding part 12, which is formed on the base
end side of the nipple 11 in the joint body 10, unrotatably in the peripheral direction and
with which the tightening member 30 movably engages and the elastically deformable
diameter contracting member 22 deformed to be contracted in diameter according to the
movement of the tightening member 30. The tubular member 21 and the diameter
contracting member 22 are disposed to be joined in the axial direction in a state in
which the tubular member 21 and the diameter contracting member 22 are attached to
the outer peripheral surface 11a of the nipple 11.
[0026]
It is desirable to provide rotation stopping means 23, which engages in the
peripheral direction, in a joining portion of the distal end part 21c of the tubular
member 21 and the base end part 22c of the diameter contracting member 22, which
join in the axial direction in the sleeve 20.
As a specific example of the rotation stopping means 23, as shown in Figs. 2(a)
to (c) and Figs. 3(a) and (b), recessed parts 23a are formed among the projections 21d on
the inner peripheral surface of the tubular member 21, a projection 23b is formed at the
base end part 22c of the diameter contracting member 22, and the recessed parts 23a
and the projection 23b are unevenly fit, whereby the diameter contracting member 22 is -
prevented from idling with respect to the tubular member 21.
As another example, although not shown in the figure, it is also possible to
change the rotation stopping means 23 to a structure other than the illustrated example,
for example, conversely to the above, form a projection at the distal end part 21c of the
tubular member 21, form recessed parts at the base end part 22c of the diameter
contracting member 22, and unevenly fit the projection and the recessed parts or
regulate, with a structure different from the uneven fitting, the idling of the diameter
contracting member 22 with respect to the tubular member 21.
[0027]
That is, as shown in Fig. 1(a) and Figs. 2(b) and (c), by inserting the tubular

member 21 of the sleeve 20 along the nipple 11 of the joint body 10, the fitting part 21a
of the tubular member 21 is fit with the protruding part 12 of the joint body 10
unrotatably in the peripheral direction. Consequently, the joint body 10 and the
tubular member 21 are integrally attached.
Thereafter, as shown in Fig. 1(a) and Figs. 2(b) and (c), by inserting the
diameter contracting member 22 of the sleeve 20 along the nipple 11, the tubular
member 21 and the diameter contracting member 22 are disposed to be joined in the
axial direction. Consequently, the tubular member 21 and the diameter contracting
member 22 of the sleeve 20 are integrally assembled to the joint body 10.
[0028]
With the tube joint A according to the example of the present invention, the
sleeve 20 is divided into the tubular member 21 that unrotatably engages with the
protruding part 12 of the joint body 10 and with which the tightening member 30
movably engages and the diameter contracting member 22 deformed to be contracted in
diameter according to the movement of the tightening member 30. The tubular
member 21 and the diameter contracting member 22 are disposed to be joined in the
axial direction. Therefore, all the components are repeatedly used every time the
deformable tube body B is connected. Even if the diameter contracting member 22,
which is a part of the sleeve 20, is plastically deformed according to the repeated use of
the sleeve 20, it is possible to repeatedly connect the tube body B by replacing only the
diameter contracting member 22 as a consumable component and reusing the tubular
member 21 and the like, which are the other components, in the sleeve 20.
Therefore, it is possible to reuse the other component (the tubular member 21)
of the sleeve 20 simply by replacing the consumable component (the diameter
contracting member 22), which is a part of the sleeve 20. It is possible to repeatedly
lay and connect the tube body B.
As a result, compared with the conventional tube joint in which, when the tube
body is connected again, not only the diameter contracting part but also the entire
tightening ring including the reusable brim part needs to be replaced, an area of
components that need to be replaced decreases and an area of reusable components
increases. There is an advantage that it is possible to achieve a reduction in
component replacement costs.
[0029]
In particular, it is desirable that the tubular member 21 of the sleeve 20.
includes the screw part 21b that screws with the tightening member 30 in the
peripheral direction, the tightening member 30 includes the pressing surface 32

opposed to and in contact with the outer peripheral surface of the diameter contracting
member 22 of the sleeve 20, and the rotation stopping means 23 engaging in the
peripheral direction is provided in a joining portion of the tubular member 21 and the
diameter contracting member 22.
In this case, even if the sleeve 20 is divided into the tubular member 21 and the
diameter contracting member 22, the tubular member 21 and the diameter contracting
member 22 are integrated in the peripheral direction by the rotation stopping means 23.
Therefore, the rotational movement of the tightening member 30 is not transmitted to
the tube body B via the diameter contracting member 22.
Therefore, there is an advantage that it is possible to prevent a twist involved
in the tightening of the tube body B.
As a result, it is possible to straightly lay and connect the tube body B without
being twisted. The tube joint A is excellent in convenience.
[0030]
In the example shown in Figs. l(a) and (b) and Figs. 3(a) and (b), the annular
groove 11b, in which the flange part 22d formed to protrude from the base end part 22c
of the diameter contracting member 22 toward the outer peripheral surface 11a of the
nipple 11 is fit in the radial direction, is formed in a concave shape on the outer
peripheral surface 11a of the nipple 11. The annular groove 11b is adjacent to the
protrusion 41 in the opposite direction (the tube slipping-off direction) U of the inserting
direction of the tube body B. As the sizes of the inner end portion of the flange part 22d
and the annular groove 11b, which fit with each other in the radial direction, it is
desirable to form the width dimension in the axial direction of the annular groove 11b
larger than the thickness dimension of the inner end portion of the flange part 22d.
At the distal end part 21c of the tubular member 21, the annular recessed part
21e, in which the base end part 22c of the diameter contracting member 22 fits
respectively in the inserting direction (the tube inserting direction) N of the tube body B
and the radial direction, is formed.
[0031]
With the tube joint A of the illustrated example, the flange part 22d of the
diameter contracting member 22 of the sleeve 20 is fit in the annular groove 11b of the
nipple 11, whereby the flange part 22d of the diameter contracting member 22 is
positioned immovably in the tube slipping-off direction U. Further, the base end part
22c of the. diameter-contracting member 22 is fit in the annular recessed part.21e of the
distal end part 21c in the tubular member 21 of the sleeve 20, whereby diameter
expansion deformation of the diameter contracting member 22 is regulated and, at the

same time, the base end part 22c and the flange part 22d of the diameter contracting
member 22 are held in the radial direction between the annular groove 11b of the nipple
11 and the annular recessed part 21e of the tubular member 21.
Therefore, it is possible to surely stop slipping off of the diameter contracting
member 22 of the sleeve 20 irrespective of the insertion of the tube body B.
As a result, it is possible to prevent an operation failure due to the slipping-off
of the diameter contracting member 22.
In particular, when the width dimension in the axial direction of the annular
groove 11b is formed larger than the thickness dimension of the inner end portion of the
flange part 22d, it is easy to fit the flange part 22d in and remove the flange part 22d
from the annular recessed part 21e and the annular groove 11b. It is possible to easily
perform component replacement work of the diameter contracting member 22.
[0032]
Further, in the example shown in Figs. 1(a) and (b) to Figs. 3(a) and (b), in a
screwing end position of the screw part 31 of the tightening member 30 into the screw
part 21b of the tubular member 21, screwing regulating means 50 engaging with each
other are formed over the tubular member 21 and the tightening member 30.
The screwing regulating means 50 is a latchet structure including concave
cutout grooves 51 disposed to be opposed to the radial direction and convex locking
claws 52 that engage with the cutout grooves 51 in the radial direction. The cutout
grooves 51 and the locking claws 52 are respectively alternately continuously formed in
the peripheral direction in a screwing end position in the screw part 21b of the tubular
member 21 and a screwing end position in the screw part 31 of the tightening member
30.
In the illustrated example, the cutout grooves 51 and the locking claws 52 are
partially formed in the peripheral direction on that base end outer peripheral surface, .
which is the screwing end position in the screw part 31 of the tightening member 30.
The cutout grooves 51 and the locking claws 52 are formed in the entire peripheral
direction on the base end inner peripheral surface, which is the screwing end position in
the screw part 31 of the tightening member 30.
Consequently, when the screw part 31 of the tightening member 30 is screwed
into the screw part 21b of the tubular member 21 and reaches the screwing end position,
the cutout grooves 51 and the locking claws 52 engage with each other such that an
operation senses,with the auditory sense or the sense, the engagement and.a resistance
feeling involved in the engagement. Further, when the screw part 31 reaches a last
position of screwing end, it is desirable to lock the screw part 31 with the engagement of

the cutout grooves 51 and the locking claws 52 and hold the tightening member 30 not
to reversely rotate in a loosening direction.
[0033]
With the tube joint A of the illustrate example, it is possible to properly execute,
with high workability, tightening management of the tightening member 30 to the
tubular member 21 without using a dedicated jig or tool.
Consequently, it is possible to surely prevent breakage and the like of the screw
part 21b of the tubular member 21 and the screw part 31 of the tightening member 30
due to excessive tightening of the tightening member 30.
[0034]
Note that, in the example, the sleeve 20 is divided into the tubular member 21
and the diameter contracting member 22. However, the present invention is not
limited to this. The tubular member 21 and the diameter contracting member 22 may
be coupled as the sleeve 20.
Further, in the example, the slip stopping means 40 is provided over the outer
peripheral surface 11a of the nipple 11 and the sleeve 20. However, the present
invention is not limited to this. The slip stopping means 40 does not have to be
provided.
In the illustrated example, the annular groove 11b, in which the flange part
22d of the diameter contracting member 22 is fit, is formed on the outer peripheral
surface 11a of the nipple 11, the annular recessed part 21e, in which the base end part
22c of the diameter contracting member 22 is fit, is formed at the distal end part 21c of
the tubular member 21, and the screwing regulating means 50 is formed in the screwing
end position of the screw part 31 of the tightening member 30 into the screw part 21b of
the tubular member 21. However, the present invention is not limited to this. Any
one of the annular groove 11b, the annular recessed part 21e,. and the screwing
regulating means 50 does not have to be formed.
[Reference Sings List]
[0035]
10 joint body
11 nipple
11a outer peripheral surface
11b, annular groove
12 protruding part
20 sleeve

21 tubular member
21b screw part
21c distal end part
21d projection
21e annular recessed part
22 diameter contracting member
22c base end part
22d flange part
23 rotation stopping means
30 tightening member
32 pressing surface
40 slip stopping means
41 protrusion
42 locking piece
B tube body
S insertion space of the tube body
N inserting direction of the tube body (tube inserting direction)
U opposite direction of the insetting direction of the tube body (tube slipping-off
direction)

[CLAIMS]
[Claim 1]
A tube joint comprising:
a joint body including a nipple provided along an insertion space of a
deformable tube body,'
a sleeve provided to be opposed to an outer peripheral surface of said nipple in
a radial direction across said insertion space of the tube body; and
a tightening member provided on an outer side of said sleeve and deforming a
part of said sleeve to be contracted in diameter toward said insertion space, wherein
a plurality of projections, which contact with said outer peripheral surface of
said nipple, are formed at a predetermined interval in a peripheral direction on an inner
peripheral surface of said sleeve.
[Claim 2]
The tube joint according to claim 1, wherein slip stopping means for engaging
said nipple and said sleeve in an axial direction is provided over said outer peripheral
surface of said nipple and said inner peripheral surface of said sleeve, and said slip
stopping means includes a protrusion formed on said outer peripheral surface of the
nipple and a locking piece that is elastically deformable in a radial direction and climbs
over and fits with said protrusion in an inserting direction of said tube body and locks in
an opposite direction to the inserting direction of said tube body.
[Claim 3]
The tube joint according to claim. 1 or 2, wherein said sleeve is divided into: a
tubular member that fits with a protruding part, which is formed on a base end side of
said nipple in said joint body, unrotatably in the peripheral direction and that engages
with said tightening member movably; and an elastically deformable diameter
contracting member deformed to be contracted in diameter according to movement of
said tightening member, and said tubular member and said diameter contracting
member are joined and disposed in the axial direction.
[Claim 4]
The tube joint according to claim 3, wherein said tubular member of said sleeve
includes a screw part that screws with said tightening member in the peripheral
direction, said tightening member includes a pressing surface opposed to and in contact
with an outer peripheral surface of said diameter contracting member of said sleeve,

and rotation stopping means mutually engaging in the peripheral direction is provided
in a joining portion of said tubular member and said diameter contracting member.
[Claim 5]
The tube joint according to claim 3 or 4, wherein an annular groove, in which a
flange part formed to protrude from a base end part of said diameter contracting
member of said sleeve toward said outer peripheral surface of said nipple is fit, is
formed in a concave shape on said outer peripheral surface of said nipple, and, at a
distal end part of said tubular member of said sleeve, an annular recessed part, in
which the base end part of said diameter contracting member fits, is formed.