Coupling apparatus

A coupling apparatus includes projections projecting axially from circumferential positions on a distal part of an annular body, each projection having an engaging hook projecting in one circumferential direction at an end part thereof. The body and the projections are formed independently of each other, and the apparatus includes a fixing structure for fixing the projections to the positions on the distal part. After inner peripheries of the projections are placed on the outer periphery of the distal part adjacent to an outward overhang, the fixing structure is detachably fixed on the outer periphery in a side of the projections axially opposing to the overhang and has an inward tapering surface fitted on an outward tapering surface of each projection to fix the projections at the predetermined positions on the outer periphery, and includes a cutout exposing the outward tapering surface of at least one projection.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a coupling apparatus.

2. Description of the Related Art

Coupling apparatuses are used for detachably connecting objects (hereinafter referred to as “objects to be connected”) each other. A coupling apparatus which includes an annular coupling body having a proximal end part attached to a predetermined part of an object to be connected and a distal end part positioned opposite to the proximal end part; and a plurality of fitting projections projecting in an axial direction of the coupling body from a plurality of predetermined circumferential positions on the distal end part of the coupling body, each fitting projection having an engaging hook projecting in one predetermined circumferential direction from its projecting end, is well known by, for example Japanese Patent Application KOKAI Publication No. 9-119577.

In a case that the predetermined parts of two objects are connected each other, the proximal end part of the coupling body of the conventional coupling apparatus as described above is attached to the predetermined part of each of the two objects to be connected. And, the coupling apparatus on the predetermined part of one object to be connected and that on the predetermined part of the other connecting member are approached coaxially to each other until the fitting projections of the distal end part of the coupling body of the one coupling apparatus fit into the fitting recesses defined between the fitting projections of the distal end part of the coupling body of the other coupling apparatus. Next, the coupling body of the one coupling apparatus is rotated in a predetermined circumferential direction relative to that of the other coupling apparatus, thereby engaging the engaging hooks of the fitting projections of the one coupling apparatus with those of the other coupling apparatus. As a result, the two coupling apparatuses are prevented from moving in directions along which the two coupling apparatuses are separated from each other, the two objects to be connected at the predetermined parts of which the two coupling apparatuses are attached are connected each other.

To disconnect the connection of such two conventional coupling apparatuses, the two coupling apparatuses are operated in reverse order to that described above.

Such a conventional coupling apparatus as described above further includes a structure as described below to prevent accidental disconnection of such two conventional coupling apparatuses.

A first disconnection preventing structure is a rotation preventing structure provided for each of the coupling bodies of the two coupling apparatuses to prevent rotation of the coupling bodies of the two coupling apparatuses after the two coupling apparatuses are connected together.

A second disconnection preventing structure is an elastic body which is provided at the end surface of the distal end part of the coupling body of each of the coupling apparatuses and which functions to move the coupling apparatuses away from each other in the axial directions thereof when the coupling apparatuses are coupled with each other to increase friction applied to the engaging hooks of the fitting projections of the coupling apparatuses.

In the conventional coupling apparatus as described above, the coupling body, the fitting projections, and the engaging hooks are formed integrally. And, when the above described conventional coupling apparatus falls on, for example, a hard floor or a road, or when two of the above described conventional coupling apparatus are strongly struck against each other, the fitting projections or engaging hooks of the coupling apparatus may be deformed or damaged. In such a case, the two coupling apparatuses can not be coupled with each other in the above described manner, so that the whole of the damaged coupling apparatus is replaced with a new one.

In addition, the more the diameter of the coupling body increase, the more the process of the fitting projections and engaging hooks formed integrally with the coupling body increase to rise a cost needed for the process.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the present invention, a is coupling apparatus comprises: an annular coupling body having a proximal end part attached to a predetermined part of an object to be connected and a distal end part positioned opposite the proximal end part; plural fitting projections projecting along an axial direction of the coupling body from plural predetermined circumferential positions on the distal end part of the coupling body, each fitting projection having an engaging hook projecting in one predetermined circumferential direction at a projecting end part thereof, and the plural fitting projections being formed independently of the coupling body; and a fixing structure which is independent of the coupling body and the fitting projections and which detachably fixes the fitting projections to the predetermined circumferential positions on the distal end part of the coupling body, the fixing structure including an insert connection member which is inserted in a through hole formed in at least one of the coupling body and the fitting projection and which is detachably connected to the other.

Two of the coupling apparatuses approach coaxially to each other to fit the fitting projections of one coupling apparatus into fitting recesses between the fitting projections of the other coupling apparatus, next, the coupling body of the one coupling apparatus is rotated in a predetermined circumferential direction relative to the coupling body of the other coupling apparatus to make the engaging hooks of the fitting projections of the one coupling apparatus engage with the engaging hooks of the fitting projections of the other coupling apparatus, thus detachably connecting the two coupling apparatuses each other.

According to another aspect of the present invention, a coupling apparatus comprises: an annular coupling body having a proximal end part attached to a predetermined part of an object to be connected and a distal end part positioned opposite the proximal end part; plural fitting projections projecting along an axial direction of the coupling body from plural predetermined circumferential positions on the distal end part of the coupling body, each fitting projection having an engaging hook projecting in one circumferential direction at a projecting end part thereof, and the plural fitting projections being formed independently of the coupling body; and a fixing structure which is independent of the coupling body and the fitting projections and which detachably fixes the fitting projections to the predetermined circumferential positions on the distal end part of the coupling body.

And, an outward overhang is provided on the outer periphery of the distal end part of the coupling body adjacent to an end surface of the distal end part to project outward in a radial direction of the coupling body. Each fitting projection has an inner periphery placed on a part of the outer periphery of the distal end part of the coupling body, the part being adjacent to the outward overhang in a side opposite to the end surface, and an outward tapering surface inclining toward the inner periphery with the outward tapering surface extending away from the projecting end part in the axial direction. After placing the inner peripheries of the plural fitting projections on the outer periphery of the distal end part of the coupling body to be adjacent to the outward overhang, the fixing structure is detachably fixed on a part of the outer periphery of the distal end part of the coupling body, the part being in a side of the outward overhang opposite to the plural fitting projections along the axial direction. The fixing structure has an inward tapering surface which fits the outward tapering surfaces of the plural fitting projections to fix the plural fitting projections coaxially on the predetermined positions of the outer periphery of the distal end part of the coupling body. Further, the fixing structure has a cutout exposing at least one outward tapering surface of the plural fitting projections, the inner peripheries of which are placed on the outer periphery of the distal end part of the coupling body adjacent to the outward overhang, the cutout allowing at least one fitting projection, the outward tapering surface of which is exposed in the cutout, to be approached to or separated from the position on the outer periphery of the distal end part of the coupling body adjacent to the outward overhang through the cutout.

Two of the coupling apparatuses approach coaxially to each other to fit the fitting projections of one coupling apparatus into fitting recesses between the fitting projections of the other coupling apparatus, next, the coupling body of the one coupling apparatus is rotated in a predetermined circumferential direction relative to the coupling body of the other coupling apparatus to make the engaging hooks of the fitting projections of the one coupling apparatus engage with the engaging hooks of the fitting projections of the other coupling apparatus, thus detachably connecting the two coupling apparatuses each other.

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

FIGS. 1 and 2show an entire configuration of the coupling apparatus10according to the first embodiment of the present invention.FIG. 1is a perspective view schematically showing two of the coupling apparatus10according to the first embodiment of the present invention in a state in which the two coupling apparatuses10are separated from each other. And,FIG. 2is a side view schematically showing the two coupling apparatuses10ofFIG. 1with one of the coupling apparatuses being in a cross section.

The coupling apparatus10is used for detachably connecting objects (hereinafter referred to as “objects to be connected”)12each other. In this embodiment, the object12to be connected is a known flexible hose in which fluid such as water is flown.

The coupling apparatus10includes an annular coupling body14which has a proximal end part14aattached to a predetermined part (one end part, in this embodiment) of the object12to be connected and a distal end part14blocated opposite to the proximal end part14a. The coupling apparatus10further includes a plurality of fitting projections16projecting from a plurality of predetermined circumferential positions on the distal end part14bof the coupling body14along an axial direction of the coupling body14, and each fitting projection16has an engaging hook18projecting from its projecting end part in one predetermined circumferential direction.

The coupling body14and the plural fitting projections16are formed by a coupling-body formation process and a fitting-projection formation process that are independent of each other. The fitting projections16are detachably fixed to predetermined circumferential positions on the distal end part14bof the coupling body14by fixing structures20which are formed by a fixing-structure formation process and which are independent of the coupling body14and fitting projections16.

The coupling body14has outer dimensions much larger than those of each fitting projection16the shape of which is complex. However, the shape of the coupling body14is simpler than that of the fitting projection16. Since the simpler shaped coupling body14is formed by the coupling-body formation process independent of the fitting-projection formation process for forming the complex shaped fitting projection16, a formation cost for the coupling body14is low.

In this embodiment, the coupling body14has a cylindrical shape, and an elastic member22is provided on an end surface of the distal end part14b. The elastic member22is an annular rubber sealing member embedded in an embedding groove14cformed annularly in the end surface of the distal end part14b, and projects from the end surface by a predetermined amount.

An outward overhang14dis provided on a position of the outer periphery of the distal end part14bof the coupling body14, the position being adjacent to the end surface of the distal end part14b, to project outward in the radial direction of the coupling body14by a predetermined amount. In this embodiment, the outward overhang14dis formed integrally with the coupling body14. However, the outward overhang14dmay be formed separately from the coupling body14and then may be fixed to the predetermined position on the outer periphery of the coupling body14by a known fixing structure including for example welding, a fixing screw, or adhesive Further, the outward overhang14dmay extend all the way on the outer periphery of the distal end part14bof the coupling body14in its circumferential direction. Alternatively, the outward overhang14dmay be disposed on each of plural circumferentially separated positions on the outer periphery of the distal end part14bof the coupling body14to correspond to each of the plural fitting projections16.

The plural fitting projections16are formed in a plurality of blocks each having a predetermined number of fitting projections16. In this embodiment, each block includes two fitting projections16. However, each block may be formed to include one, three, or more fitting projections16.

Since the fitting projection16which is far smaller in outer dimensions than each coupling body14but has a shape more complex than that of the coupling body14, is formed by the fitting-projection formation process independent of the coupling-body formation process for the coupling body14, the fitting projection16can be formed by an inexpensive formation process such as a lost-wax process, a forging process, and the like.

Each of the plural fitting projections16has an inner periphery16awhich is placed on a part of the outer periphery of the distal end part14bof the coupling body14, the part being adjacent to the outward overhang14din a side thereof opposite to the end surface of the distal end part14b. In this embodiment, each fitting projection16further has a stepped inner periphery16cwhich is in contact with an outer periphery of the outward overhang14band a stepped surface between this outer periphery and the above described fitting projection placing part of the outer periphery of the distal end part14bof the coupling body14when the inner periphery16ais placed on the fitting projection placing part of the outer periphery of the distal end part14bof the coupling body14.

The fixing structure20includes an insert connection member20bwhich is inserted in a through hole20aformed in at least one of the coupling body14and the block including the predetermined number of fitting projections16and which is detachably connected to the other. As shown clearly inFIG. 2, the through holes20aare formed in the block including the predetermined number of fitting projections16, and the insert connection member20bis a bolt with a head. According to an aspect of this invention, the insert connection member20bmay be a stud bolt or a stud pin planted in the fitting-projection placing part of the outer periphery of the distal end part14bof the coupling body14. And, a nut is screwed on the projecting end part of the stud bolt and a securing pin is combined with the projecting end part of the stud pin.

A spot facing may be formed around the through hole20ain the outer surface of the block to receive the head of the headed bolt, the nut screwed on the projecting end part of the stud bolt, or the securing pin combined with the projecting end part of the stud pin serving as the insert connection member20b, and to prevent these from projecting out from the outer surface. Such a spot facing prevent the head of the headed bolt, the nut screwed on the projecting end part of the stud bolt, or the securing pin combined with the projecting end part of the stud pin serving as the insert connection member20b, from striking an outer object and being damaged by the strike. Further, the spot facing prevent the block, that is the fitting projections16, from being displaced or separated from the predetermined position on the outer periphery of the distal end part14bof the coupling body14.

When the plural fitting projections16formed as the plural blocks as described above are placed on the predetermined positions of the outer periphery of the distal end part14bof the coupling body14, pressure deformable members24are interposed between the blocks of the fitting projections16in the circumferential direction of the coupling body14. The pressure deformable member24may be an elastic member including for example rubber, or a metal of relatively low hardness.

The pressure deformable members24prevent the plural fitting projections16fixed on the plural predetermined positions of the outer periphery of the distal end part14bof the coupling body14by the fixing structures20as described above, from being displaced in the circumferential direction.

The two coupling apparatuses10,10configured as described above with reference toFIGS. 1 and 2will be detachably connected in the following manner.

The two coupling apparatuses10approach coaxially to each other until the fitting projections16of one of the two coupling apparatus10fit in fitting recesses between the fitting projections16of the other coupling apparatus10. Next, the coupling body14of the one coupling apparatus10is rotated in a predetermined circumferential direction relative to the coupling body14of the other coupling apparatus10. As a result, the engaging hooks18of the fitting projections16of the one coupling apparatus10engage with the engaging hooks18of the fitting projections16of the other coupling apparatus10, as shown inFIG. 3, and thus the two coupling apparatuses10,10are detachably connected to each other.

At this time, the elastic members22on the end surfaces of the distal end parts14bof the coupling bodies14of the coupling apparatuses10,10are pressed against each other such to urge the coupling bodies14of these coupling apparatuses10,10to make the coupling bodies14move away from each other in their axial direction. As a result, friction force generated between engaging surfaces18aof the engaging hooks18of the fitting projections16of the one coupling apparatus10and those of the other coupling apparatus10is increased.

This means that the elastic members22configure a friction increasing mechanism26which presses the coupling bodies14of the two coupling apparatuses10to move the coupling bodies14away from each other in the axial direction when the two coupling apparatuses10,10are coupled each other, thus increasing the friction force loaded on the engaging hooks18of the fitting projections16of the coupling apparatuses10,10.

In this embodiment, the locking surface18ainclines from its proximal end at which the engaging hook18projects from the fitting projection16corresponding thereto toward its distal end such that its distal end approaches the proximal end of the fitting projection16corresponding thereto. This inclination makes the above described engagement of the locking surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus10with that of the other coupling apparatus10strengthen.

In this embodiment, the objects12to be connected to which the coupling apparatuses10are attached are known flexible hoses for flowing fluid such as water, as described above. When the fluid flows in the objects12,12after the two coupling apparatuses10, are coupled each other as described above, the elastic bodies22on the end surfaces of the distal end parts14bof the coupling bodies14of the two coupling apparatuses10expand outward in the radial direction of each coupling body14by the pressure of the fluid. The expanded elastic bodies22urges the coupling bodies14of the two coupling apparatuses10to make the coupling bodies14move further away from each other in their axial direction. As a result, the friction force generated between the locking surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus10and that of the other coupling apparatus10is further increased so that the coupling of the two coupling apparatuses10each other is also further strengthened.

In order to separate the two coupling apparatuses10,10coupled each other as described above from each other, it may be that the flow of fluid in the objects12is stopped and then the two coupling apparatuses10are operated in a manner which is reverse to the above described operation for coupling the two coupling apparatuses10,10.

In the above described embodiment, the objects12to which the coupling apparatuses10are attached are known flexible hoses for flowing fluids such as water. However, the objects12to be connected may be hard pipes or solid bodies. When a structure is formed by using hard pipes, solid bodies, or a combination thereof, the coupling apparatuses10facilitate the assembly and disassembly of such a structure.

Further, in the coupling apparatus10of the configuration according to the above described embodiment, the block having a predetermined number of fitting projections16may be fixed to each of plural coupling bodies14of different diameters by the fixing structure20.

This makes manufacturing costs for coupling apparatuses10, . . . that have coupling bodies14of different diameters being lower. That is, since the coupling bodies14are simple in structure, they can be formed easily even if their diameters are different from each other. The block with a predetermined number of fitting projections16is complex in structure and the formation thereof is complicated. However, it is not necessary to form blocks having inner peripheries16aof different dimensions to match the coupling bodies14of different diameters.

For manufacturing a plurality of coupling apparatuses10having coupling bodies14of different diameters, there is only need to prepare the coupling bodies14of different diameters, which are easy to form, and to prepare the predetermined number of blocks, each having the same dimensions as to each other and having the predetermined number of fitting projections16each of which is complex in its structure and is troublesome in its formation. When the blocks of the same dimensions are fixed to the predetermined circumferential positions on the outer periphery of the distal end part14bof each of the coupling bodies14of different diameters by the fixing structures20, each of the gaps generated between the plural blocks in the circumferential direction vary in accordance with the diameter of the outer periphery of the distal end part14bof the coupling body14. However, the variation of the gap is adjusted by the change in the dimension of the pressure deformable member24interposed in the gap in the circumferential direction. The dimension of the pressure deformable member24can be changed easily at a low cost.

That is, the coupling apparatus10of the configuration according to the above described embodiment can reduce the manufacturing costs of various coupling apparatuses10having the coupling bodies14of various diameters, compared to the conventional one. Further, even when a part of fitting projections16or engaging hooks18of each coupling apparatus10is damaged, it is enough to replace only the block having the damaged part with a new block, so that there is no need to replace the entire damaged coupling apparatus10with a new coupling apparatus10.

Second Embodiment

Next, a coupling apparatus30according to a second embodiment of the present invention will be described with reference to attachedFIGS. 4 to 6.

FIGS. 4 and 5show the entire configuration of the coupling apparatus30according to the second embodiment of the present invention.FIG. 4is a perspective view schematically showing two of the coupling apparatus30according to the second embodiment of the present invention in a state in which she two coupling apparatuses30are separated from each other, andFIG. 5is a side view of the two coupling apparatuses30ofFIG. 4with one of the two coupling apparatuses30being cross sectioned.

Most part of the component members of the coupling apparatus30according to the second embodiment is the same as that of the coupling apparatus10according to the first embodiment described above with reference toFIGS. 1 to 3. Accordingly, in the coupling apparatus30according to the second embodiment of the present invention and described below with reference toFIGS. 4 to 6, the component members corresponding to those in the coupling apparatus10according to the first embodiment of the present invention and described above with reference toFIGS. 1 to 3are indicated by the same reference numbers as those indicating the corresponding ones in the coupling apparatus10according to the first embodiment of the present invention and described above with reference toFIGS. 1 to 3, and detailed explanations thereof are omitted.

The difference in structure of the coupling apparatus30according to the second embodiment from the coupling apparatus10according to the first embodiment is as follows.

i. the planar shape of each of the plural fitting projections16;

ii. an urging mechanism32is provided on a side surface16cof the fitting projection16opposite to a side surface thereof from which the engaging hook18projects;

iii. a block has only one fitting projection16as the predetermined number of the fitting projection.

As described in the first embodiment, each block may have more than one fitting projection16.

When the two coupling apparatuses30,30are coupled with each other, the urging mechanisms32move the side surfaces16cof the fitting projections16of one coupling apparatus30away from the side surfaces16cof the fitting projections16of the other coupling apparatus30, the former side surface facing the latter side surface. As a result, the fitting projections16of the one coupling apparatus30are urged relative to the fitting projections16of the other coupling apparatus30in such a predetermined circumferential direction that the engagement of the engaging hooks18of the fitting projections16of the one coupling apparatus30with those of the other coupling apparatus30is more strengthened.

Specifically, in each of the fitting projections16of the coupling apparatus10according to the first embodiment of the present invention described above with reference toFIGS. 1 to 3, the two side surfaces located in the circumferential direction of the coupling body14and extending in the direction along the axial direction of this coupling body14extend in parallel to and in the same direction relative to the axial direction. In contrast thereto, in each of the fitting projections16of the coupling apparatus30according to the second embodiment, the two side surfaces are also located in the circumferential direction of the coupling body14and extend in the direction along the axial direction of this coupling body14, but one of the two side surfaces from which the engaging hook18projects at its projecting end part extends in the direction along the axial direction of this coupling body14and the other side surface16clocated opposite to the one side surface inclines to being away from the one side surface while it extends from the projecting end surface of the fitting projection16corresponding thereto toward the base end thereof.

And, as shown in detail inFIG. 6, the urging mechanism32provided on the other side surface16cthat inclines as described above includes a cup-shaped receptacle32aembedded in a predetermined position of the other side surface16c. The urging mechanism32further includes a ball-shaped pressing member32bdisposed at a position close to the other side surface16cin the cup-shaped receptacle32a, and an urging member32cdisposed at a position away from the other side surface16cin the cup-shaped receptacle32a. The urging member32curges the ball-shaped pressing member32bin a direction in which the ball-shaped pressing member32bprojects from the other side surface16c.

The portion close to the other side surface16cin the cup-shaped receptacle32ais worked to have a diameter smaller than that of the ball-shaped pressing member32b. As a result, the ball-shaped pressing member32burged by the pressing member32cin the cup-shaped receptacle32aas described above, is prevented from falling out from the receptacle32a.

In this embodiment, the pressing member32cis a compression coil spring, but it may be an elastic member such as a rubber member.

When the two coupling apparatuses30are detachably coupled with each other, the urging mechanism32acts in a manner as described below. When the two coupling apparatuses30,30coaxially approach each other until the fitting projections16of the one coupling apparatus30fit into the fitting recesses between the fitting projections16of the other coupling apparatus30, the ball-shaped pressing member32bof the urging mechanism32of the other side surface16cof each fitting projection16of the one coupling apparatus30and the ball-shaped pressing member32bof the urging mechanism32of the other side surface16cof each fitting projection16of the other coupling apparatus30come into contact with each other so that each ball-shaped pressing member32bmoves inward in the respective cup-shaped receptacle32aagainst the urging force of the urging member32ccorresponding thereto.

When the fitting of the fitting projections16of the one coupling apparatus30into the fitting recesses between the fitting projections16of the other coupling apparatus30becomes more deeper and the engaging surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus30approaches the base end of each fitting projection16of the other coupling apparatus30beyond the engaging surface18aof the engaging hook18of each fitting projection16of the other coupling apparatus30, the urging force of the urging member32cof the urging mechanism32on the other side surface16dof each fitting projection16of the one coupling apparatus30and the urging force of the urging member32cof the urging mechanism32on the other side surface16dof each fitting projection16of the other coupling apparatus30operate to move each fitting projection16of the one coupling apparatus30, together with the coupling boy14thereof, in a predetermined circumferential direction and to move each fitting projection16of the other coupling apparatus30, together with the coupling boy14thereof, in a predetermined circumferential direction, through the ball-shaped pressing members32bbeing kept in contact with each other as described above, so that the engaging hooks18of the fitting projections16of the one coupling apparatus30and those of the other coupling apparatus30approach each other more closely. As a result, the engaging hooks18of the fitting projections16of the one coupling apparatus30engage with the engaging hooks18of the fitting projections16of the other coupling apparatus30are engaged with each other as shown inFIG. 6, thus, the two coupling apparatuses30,30are detachably connected together.

At this time, the elastic members22on the end surfaces of the distal end parts14hof the coupling bodies14of the two coupling apparatuses30,30are pressed against each other to urge the coupling bodies14of the two coupling apparatuses30,30away from each other in their axial direction, and thus the friction force generated between the locking surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus30and the locking surface18aof the engaging hook18of each fitting projection16of the other coupling apparatus30is increased.

In addition to this, like the above described urging by the elastic bodies22, the urging force of the urging member32cof the urging mechanism32of the other side surface16dof each fitting projection16of the one coupling apparatus30and the urging force of the urging member32cof the urging mechanism32of the other side surface16dof each fitting projection16of the other coupling apparatus30further increase the friction force generated between the engaging surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus30and the engaging surface18aof the engaging hook18of each fitting projection16of the other coupling apparatus30, through the ball-shaped pressing members32being kept in contact with each other as described above.

Furthermore, it goes without saying that the coupling apparatus30according to the second embodiment described above with reference toFIGS. 4 to 6can enjoy the various actions and technical advantages obtained by the coupling apparatus10according to the first embodiment described above with reference toFIGS. 1 to 3.

Third Embodiment

Next, a coupling apparatus40according to a third embodiment of this invention will be explained with reference to attachedFIG. 7toFIG. 9.

InFIG. 7andFIG. 8, the entire configuration of the coupling apparatus40according to the third embodiment of this invention is shown.FIG. 7is a perspective view schematically showing two of the coupling apparatus40according to the third embodiment of this invention in a state that the two coupling apparatuses40are separated from each other, andFIG. 8is a side view schematically showing the two coupling apparatuses40ofFIG. 7with one of the two coupling apparatuses40being in a cross section.

Most part of the component members of the coupling apparatus40according to the third embodiment is the same as that of the coupling apparatus10according to the first embodiment described above with reference toFIGS. 1 to 3. Accordingly, in the coupling apparatus40according to the third embodiment of the present invention and described below with reference toFIGS. 7 to 9, the component members corresponding to those in the coupling apparatus10according to the first embodiment of the present invention and described above with reference toFIGS. 1 to 3are indicated by the same reference numbers as those indicating the corresponding ones in the coupling apparatus10according to the first embodiment of the present invention and described above with reference toFIGS. 1 to 3, and detailed explanations thereof are omitted.

The coupling apparatus40according to the third embodiment differs from the coupling apparatus10according to the first embodiment in a configuration of each block having a predetermined number of fitting projections16and in a configuration of a fixing structure42for detachably fixing a plurality of blocks to a plurality of predetermined circumferential positions on the outer periphery of the distal end part14bof the coupling body14.

Specifically, the outer periphery of the proximal end part of the block with the predetermined number of fitting projections16, the proximal end part being opposite to the projecting end part of the block, is shaped as an outward tapering surface16dwhich inclines from the projecting end part toward the inner periphery16a.

The fixing structure42is an annular member. After the inner peripheries16aof the blocks are placed on the circumferentially separated plural positions adjacent to the outward overhang14don the outer periphery of the distal end part14bof the coupling body14, the annular member is detachably fixed to a part opposite to the outward overhang14drelative to the plural blocks on the outer periphery of the distal end part14bof the coupling body14.

The fixing structure42has an inward tapering surface42athat fits on the outward tapering surfaces16bof the blocks when the fixing structure42is fixed on the outer periphery of the distal end part14bof the coupling body14as described above. As a result, the fitted fixing structure42detachably and coaxially fixes the blocks, that is, the fitting projections16, on the above described predetermined positions of the outer periphery of the distal end part14bof the coupling body14. At the same time, the fixing structure42holds the plural blocks, that is the plural fitting projections16, on the outward overhang14dof the outer periphery of the distal end part14bof the coupling body14in the axial direction. With this holding, the plural blocks, that is the plural fitting projections16, are fixed on the above described predetermined positions of the outer periphery of the distal end part14bof the coupling body14so as to be immovable in the axial direction.

The fixing structure42can be detachably fixed to the outer periphery of the end part of the coupling body14by means of a known fixing element including for example a fixing screw or adhesive. In this embodiment, a male thread14eis formed on the part of the outer periphery of the distal end part14bof the coupling body14, the part being opposite to the outward overhang14drelative to the plural blocks, that is the plural fitting projections16, and a female thread42bformed on the inner periphery of the fixing structure42adjacent to the axially inside end of the inward tapering surface42ais screwed on the male thread14e.

A cutout42cis further formed in the fixing structure42to be cutout from an outer end of a side of the plural blocks, that is a side of the plural fitting projections16, toward an inner end of a side opposite to the plural blocks, that is a side opposite to the plural fitting projections16. The cutout42chas a narrow square shape extending in the circumferential direction of the outer periphery of the distal end part14bof the coupling body14. In the cutout42cof the narrow square shape, the length CDL (length in the circumferential direction) in the circumferential direction of the outer periphery of the distal end part14bof the coupling body14is slightly longer than the length of each block (the length in the circumferential direction) in the circumferential direction. Further, in the cutout42cof the narrow square shape, the length ADL (length in the axial direction) in the axial direction of the coupling body14is shorter than the length (length in the axial direction) of the inward tapering surface42aof the block in the axial direction, and is preferably slightly larger than a substantially half of the length (length in the axial direction) of the inward tapering surface42aof the block.

The two coupling apparatuses40, each configuring as described above and according to the third embodiment, may be coupled with or separated from each other in the same manner as that about the two coupling apparatuses10of the first embodiment described above with reference toFIGS. 1 to 3.

In the case where the block having the damaged fitting projection16or damaged engaging hook18is replaced with a new block, at first the fixation of the fixing structure42to the outer periphery of the distal end part14bof the coupling body14is released, and then the fixing structure42is moved on the outer periphery of the distal end part14bof the coupling body14in the axial direction of the coupling body14until the inner end of the cutout42cis moved away from the end surface of the distal end part14bof the coupling body14beyond the base end surfaces of the plural blocks, that is the plural fitting projections16, placed on the plural circumferential positions of the outer periphery of the distal end part14bof the coupling body14, as shown inFIG. 9. Further, the position of the fixing structure42relative to the outer periphery of the distal end part14bof the coupling body14in the circumferential direction is adjusted to locate the both circumferential ends of the block to be replaced within a range between the both circumferential ends of the cutout42c.

As a result, the outward tapering surface16dof the block to be replaced is exposed completely within the range of the cutout42cof the fixing structure42, so that the block to be replaced can be separated from the circumferential position on the outer periphery of the distal end part14bof the coupling body14through the cutout42c, as shown inFIG. 9, and then the new block can be placed on the cleared circumferential position on the outer periphery of the distal end part14bof the coupling body14through the cutout42c.

During this time, other blocks on the outer periphery of the distal end part14bof the coupling body14are prevented from separating therefrom since the base end side parts of their outward tapering surfaces16dare covered with the projecting end side part of the inward tapering surface42aof the fixing structure42excluding the portion corresponding to the cutout42c.

A pressure-deformable member24is interposed between each of the circumferential ends of the new block and the new block side circumferential end of each of the two blocks located adjacent to the new block on the outer periphery of the distal end part14bof the coupling body14.

Thereafter, the fixing structure42is moved on the outer periphery of the distal end part14bof the coupling body14in a direction approaching the end surface of the distal end part14bof the coupling body14, that is in a direction approaching the projecting end parts of the plural fitting projections16of the plural blocks, until the inward tapering surface42aof the fixing structure42fits on the outward tapering surfaces16dof the plural blocks placed on the plural circumferential positions of the outer periphery of the distal end part14bof the coupling body14. As a result, the plural blocks, that is the plural fitting projections16, are held between the fixing structure42and the outward overhang14dof the outer periphery of the distal end part14bof the coupling body14in the axial direction, so that the plural blocks, that is the plural fitting projections16, can be detachably fixed on the plural circumferential positions of the outer periphery of the distal end part14bof the coupling body14by the fixing structure42.

That is, in the coupling apparatus40of this embodiment, the operation for replacing the block having the damaged fitting projection16or damaged engaging hook18with a new block is easy.

Fourth Embodiment

Next, a coupling apparatus50according to a fourth embodiment of this invention will be explained with reference to attachedFIG. 10toFIG. 12.

InFIG. 10andFIG. 12, the entire configuration of the coupling apparatus50according to the third embodiment of this invention is shown.FIG. 10is a perspective view schematically showing two of the coupling apparatus50according to the fourth embodiment of this invention in a state that the two coupling apparatuses50are separated from each other, andFIG. 11is a side view schematically showing the two coupling apparatuses50ofFIG. 10with one of the two coupling apparatuses50being in a cross section.

Most part of the component members of the coupling apparatus50according to the fourth embodiment is the same as that of the coupling apparatus40according to the third embodiment described above with reference toFIGS. 7 to 9. Accordingly, in the coupling apparatus50according to the fourth embodiment of the present invention and described below with reference toFIGS. 10 to 12, the component members corresponding to those in the coupling apparatus40according to the third embodiment of the present invention and described above with reference toFIGS. 7 to 9are indicated by the same reference numbers as those indicating the corresponding ones in the coupling apparatus40according to the third embodiment of the present invention and described above with reference toFIGS. 7 to 9, and detailed explanations thereof are omitted.

The difference in structure of the coupling apparatus50according to the fourth embodiment from the coupling apparatus40according to the third embodiment is as follows.

i. the planar shape of each of the plural fitting projections16;

ii. an urging mechanism32is provided on a side surface16cof the fitting projection16opposite to a side surface thereof from which the engaging hook18projects;

iii. a block has only one fitting projection16as the predetermined number of the fitting projection.

As described in the first embodiment, each block may have more than one fitting projection16.

Such a fitting projection16having the urging mechanism32on its side face16cis used in the coupling apparatus30according to the second embodiment described above with reference toFIGS. 4 to 6.

Taking all the foregoing features into consideration, the coupling apparatus50according to the fourth embodiment shown inFIGS. 10 to 13are configured by replacing the fitting projection16of the coupling apparatus40according to the third embodiment described above with reference toFIGS. 7 to 9, with the fitting protection16having the urging mechanism32on its side face16cin the coupling apparatus30according to the second embodiment described above with reference toFIGS. 4 to 6.

Accordingly, in addition to the various technical advantages obtained by the coupling apparatus40according to the third embodiment, the coupling apparatus50according to the fourth embodiment can enjoy the various technical advantages obtained by the fitting projection16having the urging mechanism32on its side face16cin the coupling apparatus30according to the second embodiment.

The two coupling apparatuses50, each of which is configured as described above and which is according to the fourth embodiment, may be coupled with or separated from each other in the same manner as that in the two coupling apparatuses40of the third embodiment described above with reference toFIGS. 7 to 9, in other words, as that in the two coupling apparatuses10of the first embodiment described above with reference toFIGS. 1 to 3.

When the two coupling apparatuses50,50are detachably coupled with each other, the urging mechanism32acts in a manner as described below (seeFIG. 6). When the two coupling apparatuses50,50coaxially approach each other until the fitting projections16of the one coupling apparatus50fit into the fitting recesses between the fitting projections16of the other coupling apparatus50, the ball-shaped pressing member32bof the urging mechanism32of the other side surface16cof each fitting projection16of the one coupling apparatus50and the ball-shaped pressing member32bof the urging mechanism32of the other side surface16cof each fitting projection16of the other coupling apparatus50come into contact with each other so that each ball-shaped pressing member32bmoves inward in the respective cup-shaped receptacle32aagainst the urging force of the urging member32ccorresponding thereto.

When the fitting of the fitting projections16of the one coupling apparatus50into the fitting recesses between the fitting projections16of the other coupling apparatus50becomes more deeper and the engaging surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus50approaches the base end of each fitting projection16of the other coupling apparatus50beyond the engaging surface18aof the engaging hook18of each fitting projection16of the other coupling apparatus50, the urging force of the urging member32cof the urging mechanism32on the other side surface16dof each fitting projection16of the one coupling apparatus50and the urging force of the urging member32cof the urging mechanism32on the other side surface16dof each fitting projection16of the other coupling apparatus50operate to move each fitting projection16of the one coupling apparatus50, together with the coupling boy14thereof, in a predetermined circumferential direction and to move each fitting projection16of the other coupling apparatus30, together with the coupling boy14thereof, in a predetermined circumferential direction, through the ball-shaped pressing members32bbeing kept in contact with each other as described above, so that the engaging hooks18of the fitting projections16of the one coupling apparatus50and those of the other coupling apparatus50approach each other more closely. As a result, the engaging hooks18of the fitting projections16of the one coupling apparatus50engage with the engaging hooks18of the fitting projections16of the other coupling apparatus50are engaged with each other as shown inFIG. 6, thus, the two coupling apparatuses50are detachably connected together.

At this time, the elastic members22on the end surfaces of the distal end parts14bof the coupling bodies14of the two coupling apparatuses50,50are pressed against each other to urge the coupling bodies14of the two coupling apparatuses50,50away from each other in their axial direction, and thus the friction force generated between the locking surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus50and the locking surface18aof the engaging hook18of each fitting projection16of the other coupling apparatus50is increased.

In addition to this, like the above described urging by the elastic bodies22, the urging force of the urging member32cof the urging mechanism32of the other side surface16dof each fitting projection16of the one coupling apparatus50and the urging force of the urging member32cof the urging mechanism32of the other side surface16dof each fitting projection16of the other coupling apparatus50further increase the friction force generated between the engaging surface18aof the engaging hook18of each fitting projection16of the one coupling apparatus50and the engaging surface18aof the engaging hook18of each fitting projection16of the other coupling apparatus50, through the ball-shaped pressing members32being kept in contact with each other as described above.

In the case where the block having the damaged fitting projection16or damaged engaging hook is replaced with a new block, at first the fixation of the fixing structure42to the outer periphery of the distal end part14bof the coupling body14is released, and then the fixing structure42is moved on the outer periphery of the distal end part14bof the coupling body14in the axial direction of the coupling body14until the inner end of the cutout42cis moved away from the end surface of the distal end part14bof the coupling body14beyond the base end surfaces of the plural blocks, that is the plural fitting projections16, placed on the plural circumferential positions of the outer periphery of the distal end part14bof the coupling body14, as shown inFIG. 12. Further, the position of the fixing structure42relative to the outer periphery of the distal end part14bof the coupling body14in the circumferential direction is adjusted to locate the both circumferential ends of the block to be replaced within a range between the both circumferential ends of the cutout42c.

As a result, the outward tapering surface16dof the block to be replaced is exposed completely within the range of the cutout42cof the fixing structure42, so that the block to be replaced can be separated from the circumferential position on the outer periphery of the distal end part14bof the coupling body14through the cutout42c, as shown inFIG. 12, and then the new block can be placed on the cleared circumferential position on the outer periphery of the distal end part14bof the coupling body14through the cutout42c.

During this time, other blocks on the outer periphery of the distal end part14bof the coupling body14are prevented from separating therefrom since the base end side parts of their outward tapering surfaces16dare covered with the projecting end side part of the inward tapering surface42aof the fixing structure42excluding the portion corresponding to the cutout42c.

A pressure-deformable member24is interposed between each of the circumferential ends of the new block and the new block side circumferential end of each of the two blocks located adjacent to the new block on the outer periphery of the distal end part14hof the coupling body14.

Thereafter, the fixing structure42is moved on the outer periphery of the distal end part14bof the coupling body14in a direction approaching the end surface of the distal end part14bof the coupling body14, that is in a direction approaching the projecting end parts of the plural fitting projections16of the plural blocks, until the inward tapering surface42aof the fixing structure42fits on the outward tapering surfaces16dof the plural blocks placed on the plural circumferential positions of the outer periphery of the distal end part14bof the coupling body14. As a result, the plural blocks, that is the plural fitting projections16, are held between the fixing structure42and the outward overhang14dof the outer periphery of the distal end part14bof the coupling body14in the axial direction, so that the plural blocks, that is the plural fitting projections16, can be detachably fixed on the plural circumferential positions of the outer periphery of the distal end part14bof the coupling body14by the fixing structure42.

That is, in the coupling apparatus50of this embodiment, the operation for replacing the block having the damaged fitting projection16or damaged engaging hook18with a new block is easy.

FIG. 13Ashows a fitting projection16″ according to a first modification of the fitting projection16used in each of the coupling apparatuses20,30,40, and50of the first to fourth embodiments described above.

The fitting projection16″ is formed with a key-shaped part preventing the engaging hooks18of the fitting projections16″ of the one coupling apparatus from engaging with the engaging hooks18of the fitting projections16″ of the other coupling apparatus when the two coupling apparatuses are coaxially approached each other and the fitting projections16″ of the one coupling apparatus fit the fitting recesses between the fitting projections16″ of the other coupling apparatus and then the coupling body14of the one coupling apparatus is rotated relative to the coupling body14of the other coupling apparatus in the predetermined circumferential direction, excluding in a case in which the two coupling apparatuses have the same shape with the same dimensions as to each other.

The key-shaped part16eis configured by a combination of a projection and a groove both of which are formed at predetermined positions on both sides of the engaging hook18in the projecting direction of the fitting projection16″ on the circumferential side surface of the fitting projection16″, on which the engaging hook18is formed. Specifically, the groove is formed in the predetermined position outside of the engaging hook18in the projecting direction, and the projection is formed in the predetermined position inside of the engaging hook18in the projecting direction.

If the circumferential side surface of the fitting projection16, on which the engaging hook18is formed but the key-shaped part16eis not formed, is moved along the circumferential side surface of the fitting projection16″, which is according to the first modification and on which the engaging hook18is formed, toward the base end of the fitting projection16″ of the first modification, as shown inFIG. 13A, the engaging hook18of the fitting projection16″ of the first modification and the engaging hook18of the fitting projection16not formed with the key-shaped part16eonly face each other and are prevented from engaging with each other by the key-shaped part16eof the fitting projection16″, as shown inFIG. 13B.

If the circumferential side surface of the fitting projection16″, which is according to the first modification and on which the engaging hook18is formed, is moved along the circumferential side surface of another fitting protection16″, which is also according to the first modification and on which the engaging hook18is also formed, toward the base end of the latter fitting projection16″ of the first modification, as shown inFIG. 14A, the key-shaped parts16eof the two fitting projections16″ are matched with each other so that the engaging hook18of the fitting projection16″ of the first modification and the engaging hook18of the fitting projection16″ of the other first modification are allowed to engage with each other.

FIG. 15Ashows a fitting projection16″ according to a second modification of the fitting projection16used in each of the coupling apparatuses20,30,40, and50of the first to fourth embodiments described above.

The fitting projection16″ according to the second modification further includes a friction increasing mechanism60which presses the coupling bodies14of the two coupling apparatuses to move them away from each other in the axial direction when the two coupling apparatuses are coupled with each other, so that the friction force generated between the engaging hooks18of the fitting projections16″ of the one coupling apparatus and the engaging hooks18of the fitting projections16″ of the other coupling apparatus increases.

The friction increasing mechanism60includes a pressing member60bwhich is accommodated in a hole60aextending from the end surface of the fitting projection16″ toward its base end, and which is slidable in the longitudinal direction of the hole60a. A guide groove60cformed in the outer periphery of the fitting projection16″ communicates with the hole60a. The guide groove60chas a longitudinally extending part extending along the longitudinal direction of the hole60a, and a bend part bending sideway relative to the longitudinal direction of the hole60aat a projecting-end-surface near end located near to the projecting end surface of the fitting projection16″ in the longitudinally extending part. An operating part60dfixed to the pressing member60bis inserted in the guide groove60c. The operating part60dis movable between a projecting-end-surface distal end which is located away from the projecting end surface of the fitting projection16″ in the longitudinally extending part of the guide groove60c, and the bend part which is located near to the projecting-end-surface near end. When the operating part60dis positioned at the projecting-end-surface distal end of the longitudinally extending part of the guide groove60c, the pressing member60bis retracted in the hole60aand does not project out from the projecting end surface of the fitting projection16″, as shown inFIG. 15A. Conversely, when the operating part60dis located in the bend part at the projecting-end-surface near end of the longitudinally extending part of the guide groove60c, the pressing member60bprojects out from the projecting end surface of the fitting projection16″ by a predetermined distance, as shown inFIG. 15B.

While the operating part60dis located in the projecting-end-surface distal end of the longitudinally extending part of the guide groove60cand the pressing member60bis retracted in the hole60bnot to project out from the projecting end surface of the fitting projection16″, as shown inFIG. 15A, the two coupling apparatuses can be coupled with or separated from each other.

When the operating part60dis moved to the bend part of the projection-end-surface near end of the longitudinally extending part of the guide groove60cto project out the pressing member60bfrom the projecting end surface of the fitting projection16″ by the predetermined distance after the coupling apparatus having at least one fitting projection16″ according to the second modification is connected to a coupling apparatus having no fitting projection16″, as shown inFIG. 15B, the projecting end of the pressing member60bpresses the counter end surface of the base end part of the fitting projection16of the coupling apparatus corresponding thereto. As a result, the coupling bodies14of the two coupling apparatuses coupled with each other are pressed to move away from each other in the axial direction, so that friction force generated between the engaging hooks18of the fitting projections16of the one coupling apparatus and the engaging hooks18of the fitting projections16of the other coupling apparatus.

It is enough that at least one fitting projection16″ according to the second modification is provided on at least one of the two coupling apparatuses to be connected. Alternatively, each of the two coupling apparatuses to be connected may have at least one fitting projection16″.

FIGS. 16A and 16Bshow a fitting projection16′″ according to a third modification of the fitting projection16used in each of the coupling apparatuses20,30,40, and50of the first to fourth embodiments described above. A handle70is fixed to an outer periphery of the fitting projection16′″ according to the third modification. The handle70facilitates the attachment and detachment of the fitting projection16′″ according to the third modification to the coupling body14of the coupling apparatus20,30,40, or50corresponding thereto. The handle70may be detachably fixed to the outer periphery of the fitting projection16′″ according to the third modification by a known detachable fixing structure such as screwing or the like. Accordingly, only when the fitting projection16′″ according to the third modification is attached to or detached from the coupling body14of the coupling apparatus20,30,40, or50corresponding thereto, the handle70is fixed to the outer periphery of the fixing projection16′″ according to the third modification, thereby facilitating the attachment and detachment of the fitting projection16′″. Then, after the fitting projection16′″ according to the third modification is fixed to the coupling body14of the coupling apparatus20,30,40, or50corresponding thereto by the fixing structure20or42, the handle70is removed from the outer periphery of the fitting projection16′″ according to the third modification, so that the handle70does not make the handling of the coupling apparatus20,30,40, or50being troublesome.