TITLE OF THE INVENTION: HOSE JOINT

FIELD OF THE INVENTION

[0001] The present invention relates to a hose joint which is easy to disassemble and clean. Specifically, the present invention relates to a hose joint provided with a nipple, a cylindrical resilient packing and a holder.

BACKGROUND OF THE INVENTION

[0002] Conventionally, this type of hose joint is provided with a nipple which has an outwardly projecting disc-shaped projection at the end of hose insertion; a cylindrical resilient packing which has an inner peripheral surface formed in a spiral concavo-convex shape capable of fitting along the shape of the outer peripheral surface of a hose or formed in a flat shape, the cylindrical resilient packing having a C-shaped cross-section with ends formed in a shape of a tube split longitudinally; and a holder which has holes to couple two pieces divided from the holder in a cylindrical shape with volts and nuts, the two pieces being formed by dividing a tube longitudinally, the holder having two projections at each end of the inner peripheral surface and a flat inner peripheral surface around the center, further the projections at one of the ends being arranged outside the disc-shaped projection of the nipple; wherein, when it is desired to exchange two different types of hoses, specifically a resin hose having outer peripheral surface formed in a spiral convex-concave shape and a resin hose having outer peripheral surface formed in a flat shape, such an exchange can be easily performed (for example, refer to the patent literature 1).

In an assembling process to attach the hose joint to a resin hose having the outer peripheral surface being formed in a spiral convex-concave shape, first, the nipple is inserted into the end of the hose up to the disc-shaped projection of the nipple; next, the resilient packing is wound one turn around the hose, the end of the resilient packing being fit along the spiral concavo-convex shape of the outer peripheral surface of the hose; then a projection at one end of a half-split holder is placed from the above and fit around the resilient packing such that the projection is in position outside the disc-shaped projection of the nipple; the other half-split holder is placed from the opposite side and fit to the other half; and thereafter the holder is fixed by tightening nuts to bolts with a L-shaped hexagonal wrench.

PRIOR ART DOCUMENTS
PATENT LITERATURE

[0003] Patent literature 1: Japanese laid-open patent application 2006-38192.

SUMMARY OF INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] However, in such a conventional hose joint, the central part of the inner peripheral surface of a holder and the outer peripheral surface of a resilient packing, which come into contact with each other, are both formed in a flat shape and in parallel with the inner peripheral surface of a hose, whereby, if the hose is pulled by a larger force than the friction resistance between the central part of the inner peripheral surface of the holder and the outer peripheral surface of the resilient packing, the outer peripheral surface of the resilient packing may slide on the inner peripheral surface of the holder, and thereby causing displacement of the resilient packing from a normal position.

Thus, a projection is formed at the end of the inner peripheral surface of a holder on the side of the hose pulled-out direction such that the projection abuts against the end of the resilient packing on the same side, whereby the displacement between the resilient packing and the holder from a normal position is prevented.

For this purpose, the height of the projection is preferably defined substantially in the same dimension as the thickness of the resilient packing.

However, to attach a hose having an outer peripheral surface formed in a spiral convex-concave shape, the projection can be arranged only outside the area where the outer peripheral surface of the hose is in spiral convex-concave shape as illustrated in Fig. 6 of the patent literature 1, resulting in unfavorable structure that only the outer peripheral portion runs into the projection at the edge of the resilient packing.

In such a partial contact, when a resilient packing is pulled together with a hose, only the outer peripheral portion runs into said projection being compressed and deformed at the edge of the resilient packing. At the same time, the other inner peripheral portion is pulled out together with the hose, and the resilient packing is deformed so as to get over the tip of the projection, whereby there is a problem to concern about the hose pulled out from the nipple for the ruptured resilient packing.

Further, in the case that a hose with a flat outer peripheral surface is attached, as shown in Fig. 7 of the patent literature 1, the height dimension of said projection is substantially the same as the thickness dimension of the resilient packing, whereby the positional displacement between the resilient packing and the holder can be prevented even if the hose is pulled. However, the positional displacement between the inner peripheral surface of the resilient packing and the outer peripheral surface of the hose is generated, and thus a problem can arise that causes only the hose to be pulled out from the nipple.

Further, when the half-split holders are put together around the resilient packing and are tightened with bolts and nuts, because the resilient packing is swollen before tightening the hose, the resilient packing is difficult to slide along the inner peripheral surface of the holder.

Specifically, when, for example, the resilient packing is made of a material with large friction resistance such as rubber, the outer peripheral surface of the resilient packing can be more difficult to slide along the inner peripheral surface of the holder, which makes the assembling work burdensome resulting in poor workability. Moreover, if the holder is tightened under the condition that the resilient packing is not properly fit, the resilient packing runs off resulting in tightening failure, and thereby there is another problem to cause the leakage of fluid passing through the hose.

[0005] Objects of the present invention are to address such problems, more specifically, that are to prevent a hose from being pulled out by a simple structure, to prevent the residual portion of the packing from running off into the joint part between two divided parts and being sandwiched between the two divided parts, to make it easy to store the resilient packing in a holder, simultaneously to make it lighter to tighten the holder, and to control a work tightening the holder so as to gradually get heavier.

SOLUTIONS TO PROBLEMS

[0006] To achieve such the objects, the present invention relates to a hose joint comprising: a nipple which is inserted into a hose and is provided so as to face the inner peripheral surface of the hose; a cylindrical resilient packing which is provided so as to face the outer peripheral surface of said hose into which said nipple is inserted, the cylindrical resilient packing being elastically deformable in the radial direction of the hose; and a holder which is cylindrical and divided into a plurality of pieces in the radial direction to cover the outer periphery of said resilient packing and immovably locked in the axial direction with respect to said nipple by mutually coupling said divided pieces together in a cylindrical shape, said resilient packing deforming radially inward by mutually tightening said divided pieces in the radial direction such that the inner peripheral surface of said hose adheres tightly to the outer peripheral surface of said nipple, wherein a slanted taper surface is formed on the inner peripheral surface of said holder facing the outer peripheral surface of said resilient packing so as to gradually approach the outer peripheral surface of said nipple in the opposite direction to the insertion direction of said hose with respect to said nipple, and said resilient packing is movably supported in said opposite direction to the insertion direction with respect to the taper surface and said nipple.

[0007] In addition to the aforementioned features, a notch concave portion is formed on either one or both of the outer peripheral surface of said resilient packing and the taper surface of said holder, the notch concave portion storing the residual portion of the packing generated in the process of the radially inward deformation of said resilient packing by means of the divided parts of said holder.

[0008] Further in addition to the aforementioned features, a plurality of protrusions and grooves extending in the circumferential direction is formed alternately in the axial direction on either one or both of the outer peripheral surface of said resilient packing and the taper surface of said holder.

[0009] Further in addition to the aforementioned features, an annular concave portion extending in a belt-like shape in the circumferential direction is formed on either one or both of the outer peripheral surface of said resilient packing and the taper surface of said holder such that the depth of the annular concave portion is gradually increased toward the center in the axial direction crossing the circumferential direction.

ADVANTAGES OF THE INVENTION

[0010] In the present invention with the aforementioned features, a taper surface is formed on the inner peripheral surface of a holder facing the outer peripheral surface of a resilient packing so as to gradually incline and approach the outer peripheral surface of a nipple in the opposite direction to the insertion direction of a hose with respect to a nipple, and by supporting the resilient packing to be movable in the opposite direction to the insertion direction with respect to the taper surface and the nipple, the resilient packing moves together with the hose in the opposite direction to the insertion direction. When the outer peripheral surface of the resilient packing is displaced from a normal position along the taper surface of the inner periphery of the holder in the opposite direction to the insertion direction, the resilient packing is further compressed and deformed in the radial direction of the hose, and thereby the inner peripheral surface of the resilient packing is further press-contacted to the outer peripheral surface of the hose such that the hose is held between the resilient packing and the nipple to be immovable in the opposite direction to the insertion direction, thus preventing a hose from being pulled out with a simple structure.

As a result, even if the resilient packing is pulled together with the hose, the end face of the resilient packing is not ruptured as in conventional devices, and therefore reliable sealing is possible.

[0011] Further, either one or both the outer peripheral surface of the resilient packing and the taper surface of the holder have a notch concave portion formed to store the residual portion of the packing, which was generated in the process of the radially inward deformation of the resilient packing caused by the divided parts of the holder, whereby, even if the residual portion of the packing is generated in the process of the radially inward deformation of the resilient packing, the residual part of the packing is stored in the notch concave portion and does not run off into the joint part between the two divided parts, and thus the residual portion of the packing can be prevented from running off into the joint part between the two divided parts and remaining interposed between the two divided parts.

As a result, the occurrence of tightening failure due to the residual portion of the packing being interposed between the two divided parts can be prevented.

[0012] Further, in the case, on either one or both the outer peripheral surface of the resilient packing and the taper surface of the holder, a plurality of protrusions and grooves extending in the circumferential direction are formed alternately in the axial direction by mutually tightening the divided parts of the holder, the outer peripheral surface of the resilient packing and the taper surface of the holder partially come into contact with each other via the protrusions. Consequently, because the friction resistance between the both parts is decreased such that the taper surface of the holder smoothly slides in the circumferential direction with respect to the outer peripheral surface of the resilient packing, the resilient packing can be easily stored in the holder, while making it easy to tighten the holder.

As a result, even if the outer peripheral surface of the resilient packing made of a material with large friction resistance such as rubber, the assembling work is not burdensome, and its workability is improved, while the leakage of fluid due to tightening failure can be reliably prevented.
Hereby, a hose joint according to the present invention is useful to disassemble and clean at the end of each day after completion of production at a site especially such as a food factory where hygiene control is strict

[0013] Further, in the case, on either one or both the outer peripheral surface of the resilient packing and the taper surface of the holder, an annular concave portion extending in a belt¬like shape is formed in the circumferential direction as to gradually increase the depth of the annular concave portion toward the center in the axial direction crossing the circumferential direction by mutually tightening the divided parts of the holder, for the first, the outer peripheral surface of the resilient packing and the taper surface of the holder partially come into contact with each other except for the annular concave portion, and tightening work is light to handle. Subsequently, with the resilient packing deforming radially inward, the annular concave portion is slightly collapsed to increase the contact area with the taper surface of the holder, thereby tightening work gets gradually heavy to handle, and as such, it is possible to control the work to tighten the holder so as to become gradually heavier.

As a result, the tightening work becomes easy to handle and therefore workability of assembling is improved.

Hereby, a hose joint according to the present invention is useful to disassemble and clean at the end of each day after completion of production at a site especially such as a food factory where hygiene control is strict

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Fig. 1 is a transverse cross-sectional view illustrating a hose joint according to an embodiment of the present invention, wherein Fig. 1(a) shows a state before tightening a hose and Fig. 1(b) shows a state after tightening the hose.

Fig. 2 is an enlarged longitudinal cross-sectional view taken along the line (2)-(2) of Fig. 1(b).

Fig. 3 is a perspective view illustrating a hose joint according to an embodiment of the present invention, wherein Fig. 3(a) to Fig. 3(f) is shown in the sequence of assembling.

Fig. 4 is a transverse cross-sectional view illustrating a hose joint according to another embodiment of the present invention, wherein Fig. 1(a) shows a state before tightening a hose and Fig. 1(b) shows a state after tightening the hose.

Fig. 5 is a perspective view illustrating a state where a resilient packing is incorporated into a hose.

Fig. 6 is a transverse cross-sectional view illustrating a hose joint according to another embodiment of the present invention, wherein Fig. 1(a) shows a state before tightening a hose and Fig. 1(b) shows a state after tightening the hose.

Fig. 7 is a perspective view illustrating a state where a resilient packing is incorporated into a hose.

Fig. 8 is a transverse cross-sectional view illustrating a hose joint according to another embodiment of the present invention, showing a state before tightening a hose. Fig. 9 is a perspective view of a resilient packing.

DESCRIPTIONS OF THE INVENTION

[0015] Hereinafter, an embodiment according to the present invention is specifically described with reference to the drawings.

As shown in Fig. 1 to Fig. 9, a hose joint A according to an embodiment of the present invention is provided with a nipple 1 which is inserted into the connection end of a flexible hose H so as to face the inner peripheral surface HI of the hose H, a cylindrical resilient packing 2 which is provided elastically deformable in the radial direction of the hose H so as to face the outer peripheral surface H2 of the hose H into which the nipple 1 was inserted, and a cylindrical holder 3 which is divided in the radial direction and formed with a plurality of divided parts 3a so as to cover the outer periphery of the resilient packing 2.
By mutually coupling the divided parts 3a of the holder 3 in a cylindrical shape, the holder 3 is fixed to be immovable in the axial direction with respect to the nipple 1, and further by mutually tightening the divided parts 3 a of the holder 3 in the radial direction, the resilient packing 2 is subjected to radially inward deformation such that the inner peripheral surface HI of the hose H adheres tightly to the outer peripheral surface la of the nipple 1.

[0016] For example, the nipple 1 is made of metal such as brass or a hard material such as hard synthetic resin and formed in a cylindrical shape so as to have the outer diameter substantially the same size as the inner diameter of the hose H or a little larger than that, otherwise the nipple 1 is formed in a thin cylindrical shape, for example, by press shaping or other shaping processes for a plate material made of deformable rigid material such as stainless steel so that the hose H is inserted along the outer peripheral surface la thereof.

[0017] A peripheral groove lb is provided on the outer peripheral surface 1 a of the nipple 1 in a concave shape, annularly extending in the circumferential direction thereof, and an annular packing lc such as an O-ring fits in the peripheral groove lb such that the outer peripheral end is partially protruded from the outer peripheral surface la of the nipple 1. Then a bulging portion Id is preferably formed in an inclined or arc-shape so as to protrude higher on the side of the peripheral groove lb and sandwich the peripheral groove lb between the back and front in the axial direction, protruding substantially at the same height as the protruding height of the annular packing lc protruding from the outer peripheral surface la of the nipple 1.

Hereby, the insertion and pulled-out of the hose H is kept easy with respect to the outer peripheral surface la of the nipple 1, while the annular packing lc can be prevented from being displaced from a normal position and running off from the peripheral groove lb. [0018] As can be seen in the example, a plurality of the peripheral grooves lb and the annular packing lc are arranged on the outer peripheral surface la of the nipple 1 at a given interval in the axial direction, and the outer peripheral surface la between these peripheral grooves lb is formed in a concave shape, whereby the hose H is difficult to pull out while reducing the weight of the nipple.

Not shown here but as another example, only a single peripheral groove lb and one annular packing lc may be arranged in the axial direction on the outer peripheral surface la of the nipple 1.
Further, in the example shown in the drawing, the bulging portion Id is arranged to protrude slightly lower than the protruding height of the annular packing lc.

Not shown here but as another example, the bulging portion Id may be arranged to protrude at the same height as the protruding height of the annular packing lc or slightly higher than the protruding height of the annular packing lc.

Further, in the back side of the peripheral groove lb in the insertion direction of the hose H (hereinafter referred to as hose insertion direction), for example, a concave portion or a convex portion is formed on the outer peripheral surface la of the nipple 1 as an locking part le for locking the after-mentioned holder 3.

[0019] At the tip of the nipple 1 beyond the peripheral groove lb in the opposite direction to the hose insertion direction (hereinafter referred to as opposite direction to the insertion direction), a flat portion If is preferably formed on the outer peripheral surface la so as to face the inner peripheral surface HI of the hose H substantially parallel thereto.

At the fringe of the flat portion If, a chevron convex portion lg is preferably formed, inclining toward the protruding end of the bulging portion Id and protruding substantially at the same height as the protruding height of the bulging portion Id.

Further, at the tip of the inner peripheral surface of the nipple 1, a reverse taper surface li is preferably formed, gradually increasing the diameter toward the end edge in of the nipple 1.

[0020] At the base end side of the nipple 1, a connection part it is subsequently provided to connect a tube connection port of other devices (not shown).

As a specific example of the connection part lj, if an internal thread is provided on the inner peripheral surface of a tube connection port of other devices to connect to the hose joint A, the connection part lj is provided with an external thread corresponding to the internal thread, and if an external thread is provided on the outer peripheral surface of the tube connection port, the connection part lj is provided with an internal thread corresponding to the external thread.

Further, as a non-slip means Ik for rotating operation, for example, as shown in Figs. 1 and 3, a plurality of planar portions are formed at a proper interval in the circumferential direction on the outer peripheral surface of the nipple 1 on the base end side so as to engage with a tool and so forth as necessary, otherwise knurling and so forth is preferably used to form a concavo-convex portion.

[0021] The resilient packing 2 is made of, for example, rubber, synthetic resin such as polyacetal resin or other elastically deformable materials having a slippery surface with good heat resistance and formed in a cylindrical shape so as to cover a given length of the connection end of the hose H in the axial direction, and as necessary, a single or a plurality of slots 2a extending in the axial direction are formed by cutting at a given interval in the circumferential direction, whereby the resilient packing 2 is constructed to be elastically deformable in the radial direction.

As seen in an example, a single slot 2a is formed by cutting the resilient packing 2.

Not shown here, but as another example, the resilient packing 2 may be constructed to be elastically deformable in the radial direction simply by selecting the material without forming the slot 2a.

Further, the outer peripheral surface 2b of the resilient packing 2 is preferably formed in a tapered shape, facing the inner peripheral surface of the after-mentioned holder 3 and gradually reducing the diameter toward the opposite direction to the insertion direction. [0022] The inner peripheral surface 2c of the resilient packing 2 faces the outer peripheral surface H2 of the hose H and has a spiral concave portion 2d formed to fit a reinforcing convex portion H3 of the spiral convex-concave shaped hose H which has the outer peripheral surface H2 integrally formed with the spiral reinforcing convex portion H3 as shown in Figs. 1-5.

Further, in another example as shown in Figs 6-8, a hose H with flat and smooth outer peripheral surface H2 may be connected instead of the spiral convex-concave shaped hose H.

In this case, depressing protrusions 2e are preferably formed to partially protrude at necessary positions of the inner peripheral surface 2c of the resilient packing 2 so as to press necessary positions such as a concave portion formed with the annular packing lc, the flat portion If, the bulging portion Id of the nipple 1 and the chevron convex portion lg-

Further, otherwise, the entire inner peripheral surface 2c of the resilient packing 2 may be formed to be flat and smooth.

[0023] The holder 3 is made of the material same as or different from the nipple 1, formed in a cylindrical shape having the inner diameter larger than the outer diameter of the hose H, and is divided into a plurality of divided parts 3a in the radial direction, while a convex portion or a concave portion and so forth is formed as a locking part 3b to engage with the locking part le of the nipple 1 to be immovable in the axial direction.

By putting these divided parts 3a on the outside of the resilient packing 2 and mutually tightening the divided parts 3a with a tightening means 3c in the radial direction, each locking part 3b is locked to be immovable in the axial direction with respect to the locking part le of the nipple 1, while the inner peripheral surface of each divided part 3a is press-contacted to the outer peripheral surface 2b of the resilient packing 2, thereby applying compression pressure to the resilient packing 2 in the radial direction.

Further, the inner peripheral surface of the divided parts 3 a constituting the holder 3 forms a taper surface 3d that inclines so as to gradually approach the outer peripheral surface la of the nipple 1 in the opposite direction to the insertion direction, and the resilient packing 2 is supported to be movable in the opposite direction to the insertion direction with respect to the taper surface 3d and the nipple 1.

[0024] Meanwhile, the hose H is made of soft synthetic resin, for example, such as vinyl chloride or a soft material such as silicon rubber and formed in a flexible and elastically deformable tubular shape.
A specific example of the hose H includes: a laminated hose which a single or a plurality of synthetic resin braids (reinforcement yarns) are buried in a hose in a spiral configuration as an intermediate layer interposed between a transparent or non-transparent outer layer and an inner layer; a spiral reinforced hose which belt-like and wire-like reinforcing materials made of such as synthetic resin or metal are integrally wound in a spiral configuration as an intermediate layer, the belt-like reinforcing material being in a rectangular cross-sectional shape and so forth, the wire-like reinforcing material being in a circular cross-sectional shape and so forth; a braid reinforced hose which a filamentous reinforcing material such as glass fiber or fire-retardant fiber is braided around the outer peripheral surface of a hose; a spiral reinforced hose which a metal wire rod or a wire rod made of hard synthetic resin is buried in a hose in a spiral configuration; a single layered hose made of soft synthetic resin; and so forth.

In the examples shown in Fig. 1 to Fig. 5, a spiral convex-concave shaped hose H is used, wherein the inner peripheral surface HI of the hose H is formed to be flat and smooth, and a spiral reinforcing convex portion H3 is integrally formed with the outer peripheral surface H2.

In the examples shown in Fig.6 to Fig. 9, a hose H is used wherein the inner peripheral surface HI and the outer peripheral surface H2 of the hose H are formed to be flat and smooth.

[0025] According to such a hose joint A, in a state before the hose is tightened as shown in Fig. 1(a), by tightening the divided parts 3a of the holder 3 with a tightening means 3c in the radial direction, the resilient packing 2 is subjected to radially inward deformation such that the inner peripheral surface HI of the hose H adheres tightly to the outer peripheral surface la of the nipple 1 as shown in Fig. 1(b).
In response to a force applied to the hose H in the opposite direction to the insertion direction under this tightening condition, the resilient packing 2 moves together with the hose H in the opposite direction to the insertion direction as shown by an arrow B in Fig. 1(b). When the outer peripheral surface 2b of the resilient packing 2 is displaced from a normal position along the inner peripheral taper surface 3d of the holder 3 in the opposite direction to the insertion direction, the resilient packing 2 is further compressed and deformed by the taper surface 3d in the radial direction, and thereby the inner peripheral surface 2c of the resilient packing 2 is further press-contacted to the outer peripheral surface H2 of the hose H such that the hose H is held between the resilient packing 2 and the nipple 1 to be immovable in the opposite direction to the insertion direction, thus preventing the hose H from being pulled out.

As such, the pulled-out of the hose H can be prevented with a simple structure. [0026] Further in the case that a flat portion If is formed at the tip of the outer peripheral surface la of the nipple 1 so as to face the inner peripheral surface HI of the hose H substantially parallel thereto, by mutually tightening the divided parts 3a of the holder 3 in the radial direction, the bulging portion Id protruding from the outer peripheral surface la of the nipple 1 is pushed into the inner peripheral surface HI of the hose H while the flat

portion If comes into surface contact with the inner peripheral surface HI of the hose H, whereby the inner peripheral surface HI of the hose H adheres tightly to the flat portion If of the tip of the nipple 1 such that no gap occurs, and thus the intrusion, retention or accumulation of the fluid passing through inside the hose H can be advantageously prevented.

In the case that a chevron convex portion lg is formed, inclining from the flat portion If toward the protruding end of the bulging portion Id and protruding substantially at the same height as the protruding height of the bulging portion Id, when the inserted hose H gets over a chevron convex portion lg, the hose H is extendedly deformed by the inner diameter and thereafter reaches to the bulging portion Id with the inner diameter remaining extendedly deformed, whereby the hose H can be easily inserted into the nipple 1.

Further, in the case that at the tip of the inner peripheral surface of the nipple 1, a reverse taper surface li is formed, gradually increasing the diameter toward the end edge lh of the nipple 1, the reverse taper surface li continues to the inner peripheral surface HI of the hose H, whereby no liquid pool occurs near the end edge lh of the nipple 1 with fluid smoothly flowing.

[0027] Further, on either one or both the outer peripheral surface 2b of the resilient packing 2 and the taper surface 3d that is the inner peripheral surface of the holder 3, a notch concave portion 4a is preferably formed to store the residual portion of the packing, which was generated in the process of the radially inward deformation of the resilient packing 2 caused by the holder 3.

Further, on either one or both the outer peripheral surface 2b of the resilient packing 2 and the taper surface 3d that is the inner peripheral surface of the holder 3, a plurality of protrusions 4b and grooves 4c extending in the circumferential direction is formed alternately in the axial direction, whereby a low friction portion 4d is preferably formed.

Further, on either one or both the outer peripheral surface 2b of the resilient packing 2 and the taper surface 3d that is the inner peripheral surface of the holder 3, an annular concave portion 4e extending in a belt-like shape in the circumferential direction is formed so as to gradually increase the depth toward the center in the axial direction crossing the circumferential direction.

Hereinafter, each embodiment according to the present invention is described with reference to the drawings.

Embodiment 1
[0028] As shown in Fig. 1 to Fig. 3, the embodiment 1 illustrates a case that a notch concave portion 4a is formed to store the residual portion of the packing generated in the process of the radially inward deformation of the resilient packing 2 by the holder 3 at either one or both the outer peripheral surface 2b of a resilient packing 2 and the taper surface 3d that is the inner peripheral surface of a holder 3, the resilient packing 2 being elastically deformable in the radial direction by forming a single slot 2a on a cylinder body made of such as rubber throughout the full length of the body in the axial direction. [0029] In an example shown in Fig. 1 to Fig. 3, the outer peripheral surface 2b of the resilient packing 2 is formed to be flat and smooth, and notch concave portions 4a are formed on both sides of the slot 2a so as to sandwich the slot.

Not shown here, but as another example, it is possible to form the notch concave portion 4a on the taper surface 3d that is the inner peripheral surface of the holder 3 or to form a single or a plurality of notch concave portions 4a on any positions on the outer peripheral surface 2b of the resilient packing 2 or the taper surface 3d that is the inner peripheral surface of the holder 3.

Further, a projecting piece 2f is integrally formed with the end of the resilient packing 2 in the hose insertion direction, facing the edge face (cut section) H4 of the inserted hose H, and the hose H is inserted to the extent that the edge face H4 of the hose H runs into the projecting piece 2f.

Further, depressing protrusions 2e are preferably formed at the positions where a spiral concave portion 2d is not formed on the inner peripheral surface 2c of the resilient packing 2 so as to face positions requiring depression such as the annular packing lc, the flat portion If, and a concave portion formed between a bulging portion Id and a chevron convex portion lg of the nipple 1 and so forth.

[0030] In an example shown in Fig. 1 to Fig. 3, a holder 3 is divided into a pair of divided parts 3a, and a bolt as a tightening means 3c is inserted into a through-hole 3e provided on the pair of the divided parts 3a and is screwed thereinto, whereby the divided parts 3a mutually move in the radial direction so as to approach or separate from each other.

Further, a spiral convex-concave shaped hose is connected as the hose H wherein a spiral reinforcing convex portion H3 is integrally formed with the outer peripheral surface H2.

[0031] Hereinafter, the connecting process of the hose H using such a hose joint A is described in sequence of the process.

First, as shown in Figs. 3(a) and 3(b), the connection end of the hose H is covered with a resilient packing 2, and the spiral concave portion 2d of the resilient packing 2 fits the spiral reinforcing convex portion H3 of the hose H.

Thereafter, as shown in Figs. 3(b) and 3(c), a nipple 1 is inserted into the connection end of the hose H such that these hose H and resilient packing 2 are integrated with the nipple 1.

[0032] Thereafter, as shown by a two-dot chain line in Fig. 2 and as shown in Fig. 3(d), the outside of the resilient packing 2 is covered with a pair of the divided parts 3a respectively to make a cylindrical form, when, as shown in Fig. 1(a), a convex portion that is a locking part 3b of the divided parts 3a engages with a concave portion that is a locking part le of the nipple 1 such that the divided parts 3a is locked to the nipple 1 to be immovable in the axial direction.

While holding the engagement, a bolt as a tightening means 3c is inserted into a through-hole 3e of each divided part 3a and screwed thereinto as shown in Fig. 3(e), whereby the divided parts 3 a move in the radial direction so as to mutually approach each other as shown in Fig. 1(b), the solid line in Fig. 2, and Fig. 3(f), and thus the resilient packing 2 is compressed in the radial direction while being subjected to radially inward deformation.

[0033] In response to the radially inward deformation of the resilient packing 2 being interposed between the pair of the divided parts 3a, the residual portion of the packing is generated on the outer peripheral surface 2b of the resilient packing 2 and this residual portion runs off to the joint part 3f of the pair of the divided parts 3a, and thus this run-off portion may be interposed between the pair of the divided parts 3a, thereby making it difficult to tighten further.

To resolve the problem, either one or both the outer peripheral surface 2b of the resilient packing 2 and the taper surface 3d that is the inner peripheral surface of the holder 3 have a notch concave portion 4a formed to store the residual portion of the packing, which was generated in the process of the radially inward deformation of the resilient packing 2 caused by the holder 3.

In the embodiment 1, a notch concave portion 4a is formed on the outer peripheral surface 2b of the resilient packing 2 along a slot 2a throughout the full length in the axial direction, whereby even if the residual portion of the packing is generated in the process of the radially inward deformation of the resilient packing 2, the residual portion of the packing is stored in the notch concave portion 4a without running off to the joint part 3f between two divided parts 3 a.

As such, the residual portion of the packing can be advantageously prevented from running off to the joint part 3f between the two divided parts 3a and being interposed therebetween.

[0034] Further, as seen in the example, in the case that the depressing protrusion 2e is arranged in a position where the spiral concave portion 2d is not formed on the inner peripheral surface 2c of the resilient packing 2, by mutually tightening the divided parts 3 a of the holder 3 in the radial direction, the depressing protrusion 2e of the resilient packing 2 pushes the hose H into a concave portion formed between the bulging portion Id and the chevron convex portion lg, whereby the inner peripheral surface HI of the hose H gets caught in a stepped portion from the concave portion to the chevron convex portion lg,
which makes it difficult to pull out the hose H, and thus there is also an advantage that the hose H cannot be easily pulled out when tightened.

Embodiment 2
[0035] As shown in Fig. 4 and Fig. 5, the configuration of the embodiment 2 has the same structure as that of the embodiment 1 as shown in Fig. 1 to Fig. 3 except that a plurality of protrusions 4b and grooves 4c extending in the circumferential direction are formed alternately in the axial direction only on the outer peripheral surface 2b of the resilient packing 2 whereby a low friction portion 4d is provided.

[0036] In an example shown in Fig. 4 and Fig. 5, a low friction portion 4d is arranged throughout on the resilient packing 2 in the axial direction by forming a plurality of protrusions 4b and grooves 4c alternately in the axial direction so that the low friction portion 4d is formed to have a saw-like shape in cross-section.
Not shown here but as another example, it is also possible to form a low friction portion 4d on the taper surface 3d that is the inner peripheral surface of the holder 3 by forming a plurality of protrusions 4b and grooves 4c alternately in the axial direction or to form the protrusions 4b and the grooves 4c being in a concavo-convex shape that is different from the saw-like shape in cross-section.

[0037] Notably, when the divided parts 3 a of the holder 3 are moved in the radial direction to approach each other by a tightening means 3c, the taper surface 3d that is the inner peripheral surface of these divided parts 3a slides along the outer peripheral surface 2b of the resilient packing 2 while compressing the resilient packing 2 in the radial direction to deform radially inward.

If the outer peripheral surface 2b of the resilient packing 2 is made of, for example, rubber and so forth and the surface friction resistance is high, the outer peripheral surface 2b of the resilient packing 2 does not smoothly slide with respect to the taper surface 3d that is the inner peripheral surface of each divided part 3 a, and therefore it has been difficult to compress the resilient packing 2 uniformly in the circumferential direction, while it is concerned that a work to tighten the each divided part 3a by a tightening means 3c gets harder.

That is, in the embodiment 1, even if the divided parts 3a are moved to approach each other in the radial direction by bolts as a tightening means 3c, the taper surface 3d that is the inner peripheral surface of each divided part 3a does not smoothly slide with respect to the outer peripheral surface 2b of the resilient packing 2, whereby the work to tighten each divided part 3a by bolts as the tightening means 3c has become harder. [0038] As such, on either one or both the outer peripheral surface 2b of the resilient packing 2 and the taper surface 3d that is the inner peripheral surface of the holder 3, a low friction portion 4d are provided by forming a plurality of protrusions 4b and grooves 4c extending in the circumferential direction, alternately in the axial direction.

In the embodiment 2, by arranging a plurality of protrusions 4b and grooves 4c extending in the circumferential direction along the outer peripheral surface 2b of the resilient packing 2 alternately in the axial direction, only the tips of the protrusions 4b partially come into contact with the taper surface 3d that is the inner peripheral surface of the divided parts 3a while the friction resistance between both parts is reduced, and thus the taper surface 3d that is the inner peripheral surface of each divided part 3a smoothly slides on the outer peripheral surface 2b of the resilient packing 2.

As such, there is an advantage that the resilient packing 2 can be compressed more uniformly in the circumferential direction and the work to tighten each divided part 3 a by the tightening means 3c can be handled more lightly than the embodiment 1 as shown in Fig. 1 to Fig. 3.

Embodiment 3
[0039] As shown in Fig. 6 and Fig. 7, the configuration of the embodiment 3 is the same as that of the embodiment 1 as shown in Fig. 1 to Fig. 3 or that of the embodiment 2 as shown in Fig. 4 and Fig. 5 except that an annular concave portion 4e extending in a belt-like shape in the circumferential direction is formed only on the outer peripheral surface 2b of the resilient packing 2 such that the depth of the annular concave portion 4e is gradually increased toward the center in the axial direction crossing the circumferential direction, while a hose having flat and smooth outer peripheral surface H2 is connected as the hose H.

[0040] In an example as shown in Fig. 6 and Fig. 7, a plurality of the annular concave portions 4e are arranged at a given interval on the outer peripheral surface 2b of the resilient packing 2 and each annular concave portion 4e is provided in a concave shape having arc shaped cross-section.

Not shown here but as another example, it is possible to form an annular concave portion 4e on the taper surface 3d that is the inner peripheral surface of the holder 3, to form only a single annular concave portions 4e on any positions on the outer peripheral surface 2b of the resilient packing 2 or the taper surface 3d that is the inner peripheral surface of the holder 3, or to provide the annular concave portion 4e in concave shape having another cross-section shape such as substantially V-shape.

Further, in the example shown in the drawing, a plurality of low friction portions 4d are formed by alternately arranging a plurality of protrusions 4b and grooves 4c in the axial direction between a plurality of annular concave portions 4e which are arranged on the outer peripheral surface 2b of the resilient packing 2, and a depressing protrusion 2e is formed on the inner peripheral surface 2c corresponding to a part or a whole of arrangement positions of these low friction portions 4d so as to face positions that require depression such as the annular packing lc, the flat portion If, and a concave portion formed between the bulging portion Id and the chevron convex portion lg of the nipple 1 and so forth.

Not shown here but as another example, a plurality of annular concave portions 4e may be arranged to leave the surface between them flat and smooth without further work. [0041] As such, in the embodiment 3 shown in Fig. 6 and Fig. 7, because the divided parts 3 a are mutually moved to approach each other in the radial direction by the tightening means 3c and the outer peripheral surface 2b of the resilient packing 2 partially comes into contact with the taper surface 3d of the holder 3 except for the annular concave portion 4e, the tightening work by the tightening means 3c, that is, to screw and fasten with a tool, is light at the beginning of tightening. Thereafter, because the resilient packing 2 is subjected to radially inward deformation, the annular concave portion 4e is slightly collapsed and the contact area with the taper surface 3d of the holder 3 is increased, thereby gradually making the tightening work by the tightening means 3c heavier.

As such, there is an advantage that the tightening work by the holder 3 can be more controlled so as to gradually become heavier than that of the embodiment 1 as shown in Fig. 1 to Fig. 3 or the embodiment 2 as shown in Fig. 4 and Fig. 5.

[0042] Further, as seen in the example, in the case that the depressing protrusion 2e of the resilient packing 2 is arranged so as to face the concave portion which is formed between the bulging portion Id and the chevron convex portion lg, due to the mutual tightening in the radial direction by the divided parts 3a of the holder 3, the depressing protrusion 2e of the resilient packing 2 depresses and pushes the hose H into the concave portion which is formed between the bulging portion Id and the chevron convex portion lg, whereby the inner peripheral surface HI of the hose H gets caught in a stepped portion from the concave portion to the chevron convex portion lg, which makes it difficult to pull out the hose H in the opposite direction to the insertion direction, and thus there is also an advantage that the hose H cannot be easily pulled out when it is tightened. [0043] Furthermore, as shown in Fig. 6 and Fig. 7, in the case that a hose with a flat and smooth outer peripheral surface H2 is connected as the hose H, a depressing protrusion 2e is formed on the inner peripheral surface 2c of the resilient packing 2 so as to protrude toward a concave portion lm which is formed between a plurality of peripheral grooves lb, and by tightening the hose H with the inner peripheral surface of the holder 3, the edge face H4 of the hose H is guided to advance toward the projecting piece 2f so as to be inserted smoothly, and the hose H partially bends between the concave portion lm and the depressing protrusion 2e which are mutually facing each other such that the hose H is sandwiched between the concave portion lm and the depressing protrusion 2e, and thus the inner peripheral surface HI and the outer peripheral surface H2 adhere tightly to the concave portion lm and the depressing protrusion 2e respectively, thereby preventing the pulled-out of the hose H.

Embodiment 4
[0044] As shown in Fig. 8 and Fig. 9, the configuration of the embodiment 4 is the same as that of the embodiment 1 as shown in Fig. 1 to Fig. 3 except that a plurality of slots 2a is formed at a given interval in the circumferential direction on a cylindrical resilient packing 2 which is made of synthetic resin and so forth such that the cylindrical resilient packing 2 is elastically deformable in the radial direction, and a hose with flat and smooth outer peripheral surface H2 is connected as the hose H.

[0045] In an example as shown in Fig. 8 and Fig. 9, a single slot 2a is formed in the axial direction throughout the full length of the cylindrical body, while other slots 2a are formed in the axial direction partially from one opening fringe to the other opening fringe of the resilient packing 2, and a notch concave portions 4f are also formed on the outer peripheral surface 2b along these other slots 2a to prevent the residual portion of the packing from being interposed between the divided parts of a holder.
Not shown here but as another example, other slots 2a can be formed in the axial direction partially apart from both the opening fringes of the resilient packing 2. [0046] As such, the embodiment 4 as shown in Fig. 8 and Fig. 9 can provide the same effects as the embodiment 1 which was described above, and further if the embodiment 4 is configured in the same manner as the embodiment 2 and the embodiment 3 which were described above, the embodiment 4 can also provide the same effects as these embodiments.

[0047] Further, in the aforementioned embodiments 1 to 3, although a single slot 2a is provided on the resilient packing 2 to form the resilient packing 2 to be elastically deformable in the radial direction, the resilient packing 2 is not limited to this formation and may be formed to be elastically deformable in the radial direction without providing the slot 2a.

Further, although the embodiment 1 and the embodiment 2 disclose a spirally convex-concave shaped hose H which has a spiral reinforcing convex portion H3 integrally formed on the outer peripheral surface H2 to be connected as the hose H, the hose H is not limited to these embodiments, and the hose H with flat and smooth outer peripheral surface Ff2 may be connected.

Further, in the embodiment 3 and the embodiment 4, although a hose H with flat and smooth outer peripheral surface H2 is disclosed to be connected as the hose H, the hose H is not limited to these embodiments, and a spirally convex-concave shaped hose H which has a spiral reinforcing convex portion H3 integrally formed on the outer peripheral surface H2 may be connected.

Also, the embodiment 1 has a notch concave portion 4a formed on the outer peripheral surface 2b of the resilient packing 2, the embodiment 2 has a low friction portion 4d consisting of protrusions 4b and grooves 4c arranged on the outer peripheral surface 2b of the resilient packing 2, and the embodiment 3 has an annular concave portion 4e formed on the outer peripheral surface 2b of the resilient packing 2, but not limited to these embodiments, the notch concave portion 4a, the low friction portion 4d consisting of the protrusions 4b and the grooves 4c, and the annular concave portion 4e may be formed or arranged on the taper surface 3d of the holder 3.

EXPLANATION OF SYMBOL

[0048] 1 nipple
la outer peripheral surface
2 resilient packing
2b outer peripheral surface 2d spiral concave portion
3 holder
3a divided parts
3d taper surface
4a notch concave portion
4b protrusion
4c groove
4e annular concave portion
Hhose
HI inner peripheral surface
H2 outer peripheral surface

Claims amended under the article 19 What is claimed is:

1. A hose joint comprising: a nipple which is inserted into a hose and is provided so as
to face the inner peripheral surface of the hose;

a cylindrical resilient packing which is provided so as to face the outer peripheral surface of said hose into which said nipple is inserted, the cylindrical resilient packing being elastically deformable in the radial direction of the hose; and

a holder which is cylindrical and divided into a plurality of pieces in the radial direction to cover the outer periphery of said resilient packing and locked to be immovable in the axial direction with respect to said nipple by mutually coupling said divided pieces together in a cylindrical shape, said resilient packing deforming radially inward by mutually tightening said divided pieces in the radial direction such that the inner peripheral surface of said hose adheres tightly to the outer peripheral surface of said nipple,
wherein a slanted taper surface is formed on the inner peripheral surface of said holder facing the outer peripheral surface of said resilient packing so as to gradually approach the outer peripheral surface of said nipple in the opposite direction to the insertion direction of said hose with respect to said nipple and said resilient packing is supported to be movable in said opposite direction to the insertion direction with respect to the taper surface and said nipple, and

wherein a plurality of protrusions and grooves extending in the circumferential direction is formed alternately in the axial direction on either one or both of the outer peripheral surface of said resilient packing and the taper surface of said holder.

2. The hose joint according to claim 1, wherein a notch concave portion is formed on either one or both of the outer peripheral surface of said resilient packing and the taper surface of said holder, the notch concave portion storing the residual portion of the packing generated in the process of the radially inward deformation of said resilient packing by means of the divided parts of said holder.

3. (cancelled)

4. The hose joint according to claim 1, claim 2, wherein an annular concave portion extending in a belt-like shape in the circumferential direction is formed on either one or both of the outer peripheral surface of said resilient packing and the taper surface of said holder such that the depth of the annular concave portion is gradually increased toward the center in the axial direction crossing the circumferential direction.