Abstract:
A member coupling device is provided for use with a treatment apparatus which uses chemicals. The member coupling device is formed with a tapered hole including a tapered hole portion which diverges toward an opening. A tapered implant is inserted into the tapered hole from an enlarged side of the tapered hole portion and fitted therein. The implant includes a tapered portion in contact with the tapered hole portion, and a first thread formed on the tapered portion. With the implant fitted in the tapered hole, a member is placed in contact with the member coupling device. A second thread formed on a fastening member is engaged with the first thread of the implant in a screw coupling configuration to mount the member on the member coupling device.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application relates to U.S. patent application Ser. No. 08/803,232 filed on Feb. 20, 1997 based on Japanese Patent Application Number 8-036530 filed on Feb. 23, 1996 and assigned to the present assignee. The content of the application is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus for installing a material which is processed by using chemicals. 
     Chemical treatment facilities are known for performing acid washing and alkaline washing as a pretreatment of plating. For such processing, members under treatment must be fixed in such treatment facilities which require use of chemicals. To this end, resin-based materials resistant to acid and alkali are generally used for a base on which a member under treatment is mounted. Also, for mounting the member under treatment on the base, it is necessary to fix the member on the base with a screw, or the like. However, the base made of the resin-based material is not suitable for a general screw fastening structure due to the soft nature of the resin-based material. Thus, in conventional chemical treatment facilities, to fix a member on a base made of a resin-based material, a coil-shaped screw is embedded as a reinforcement into an internally threaded hole formed in the base, and a bolt or the like is fastened to the screw reinforcement. This way, a member under treatment is fixed on the base using the bolt. 
     The reinforcement member is a type of coil spring which has a strength substantially identical to the male thread of the bolt and has a rhombic shape in cross-section. The reinforcement member is inserted into a hole which is previously threaded such that the outer periphery of the reinforcement member fits into the threaded hole, and a male thread is inserted along the inner face of the reinforcement member. 
     SUMMARY OF THE INVENTION 
     Since the above-mentioned reinforcement member is damaged by acid or the like to result in deformation thereof, it cannot be used for a long term. If this spring-shaped reinforcement member is readily replaceable, the base can be reused by replacing a damaged reinforcement member with a new one. However, since removal of the spring-shaped reinforcement member is difficult, the reuse of the base is also difficult, thus giving rise to a problem that the entire base including the reinforcement member must be replaced. Also, in treatment facilities using chemicals, it is desired in some cases that not only members under treatment but also fixtures of members coupled to a treatment facility itself, such as an open/close lid of the treatment facility be replaced in part. In such a case, a spring-shaped reinforcement member, if used in a treatment facility, would require replacement of the treatment facility itself due to the difficult removal of the reinforcement member. 
     It is an object of the present invention to provide an apparatus for installing a material which is processed by using chemicals, which allows for easy replacement of a part of a treatment facility in which chemicals are used. 
     To achieve the above object, the present invention provides an apparatus for installing a material which is processed by using chemicals for coupling a first member to a second member. The member coupling device includes a tapered implant which is embedded in a tapered hole portion formed in the first member, and is comprised of a tapered portion having an outer surface in the form of a circular truncated cone, and a projecting portion formed at an end face on an enlarged side of the tapered portion, protruding from the tapered portion, and having a plane orthogonal to the axial direction of the tapered portion. The first and second members are sandwiched between the tapered implant and a fastening member and coupled to each other by engaging the tapered implant with the fastening member in a screw coupling configuration. 
     With the structure as described, the tapered implant for fastening the first and second members can be readily removed and again embedded, thereby making it possible to readily replace a portion of a treatment facility which uses chemicals. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view generally illustrating the structure of a member coupling device according to one embodiment; 
     FIG. 2 is a cross-sectional view generally illustrating the structure of a member coupling device according to the embodiment; 
     FIG. 3 is a perspective view illustrating the structure of a tapered implant for use in the member coupling device according to the embodiment; 
     FIG. 4 is a cross-sectional view illustrating the structure of the tapered implant according to the embodiment; 
     FIGS. 5A to  5 D are diagrams illustrating a sequence of steps for embedding the tapered implant into a jig base in accordance with the embodiment; 
     FIGS. 6A to  6 E are diagrams illustrating a sequence of steps for removing the tapered implant from the jig base in accordance with the embodiment; 
     FIGS. 7A to  7 E are diagrams illustrating a sequence of steps for removing the tapered implant from the jig base in accordance with the embodiment; 
     FIGS. 8A to  8 D are diagrams illustrating a sequence of steps for machining the tapered hole in the jib base for reuse in accordance with the embodiment; 
     FIGS. 9A to  9 E are partially cross-sectional views illustrating a sequence of steps for embedding the tapered implant into a jig base in accordance with the embodiment; 
     FIGS. 10A to  10 E are diagrams illustrating a sequence of steps for embedding the tapered implant into a jig base in accordance with the embodiment; and 
     FIG. 11 is a cross-sectional view generally illustrating the structure of a member coupling device according to another embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following, an apparatus for installing a material which is processed by using chemicals according to one embodiment of the present invention will be described in terms of the structure with reference to FIGS. 1 to  10 . 
     Referring first to FIGS. 1 and 2, the apparatus for installing a material which is processed by using chemicals for plating or the like, according to the embodiment, will be described centered on the general structure thereof. 
     FIGS. 1 and 2 are cross-sectional views generally illustrating the structure of a member coupling device. 
     As illustrated in FIG. 1, a jig base  20  is previously formed with a hole  22  extending therethrough, and a tapered implant  10  is embedded in the hole  22  to form the member coupling device. The jig base  20  is made of a resin-based material which is resistant to acid and alkali. 
     A jig base, when made of a resin-based material, is not suitable for a general screw fastening structure due to its soft nature. In a conventional chemical treatment facility, a coil-shaped screw is embedded in an internally threaded hole formed in a base as a screw reinforcement. In contract, in this embodiment, the jig base  20  is formed with a hole  22 , which is a simple opening, such that the tapered implant  10  is embedded in the hole  22 . The tapered implant  10  is formed with a female thread  12  on the inner face. The tapered implant  10  may be made of a material relatively resistant to acid and alkali such as titanium, hard plastic, stainless steel, or the like. Though relatively expensive, a tapered implant made of titanium could be used for a long term due to its high resistance to acid and alkali. A tapered implant made of hard plastic, though less resistant to acid and alkali as compared with titanium, is extremely cheap so that the jig base  20  can be reused by replacing a damaged tapered implant  10  with a new one. A tapered implant made of stainless steel has intermediate characteristics between those made of titanium and hard plastic. Specifically, the tapered implant made of stainless steel is more expensive than that made of hard plastic but is cheaper than that made of titanium. Also, the stainless tapered implant, though inferior to the titanium-made tapered implant, has similar acid and alkali resistance to the hard plastic tapered implant, and has a higher strength than the hard plastic tapered implant. 
     As described above, when a coil-shaped screw is embedded into a jig base, the difficulties in removing the coil-shaped screw from the jig base makes it practically impossible to reuse the jig base. On the contrary, the tapered implant  10  used in this embodiment makes it possible to reuse the jig base  20  thanks to its easiness of removal from the jig base  20 . 
     A structure for mounting a member under treatment using the tapered implant  10  will be described later with reference to FIG.  2 . The tapered implant  10  will be further described later in terms of the shape with reference to FIGS. 3 and 4. Also, the recovery of the tapered implant  10  will be described later with reference to FIGS. 5 to  10 . 
     Next, the structure for mounting a member under treatment using the tapered implant  10  according to this embodiment will be described with reference to FIG.  2 . 
     A member  30  under treatment such as plating or the like is carried on the jig base  20  in which the tapered implant  10  has been previously embedded. Further, a masking member  40  is placed on the member  30 , and a bolt B, which serves as a fastening member, is inserted through central openings extending through the member under treatment  30  and the masking member  40  and engaged with a female thread formed on the inner face of the tapered implant  10  to securely mount the member under treatment  30  on the jig base  20 . 
     Here, as the member under treatment  30 , a diamond grind stone, for example, may be mounted on the jig base  20 . Of course, any other material other than the diamond grind stone may be contemplated. The diamond grind stone, after industrial diamond has been applied thereon, is formed with a plated film M to conceal the diamond to fix the diamond to the surface of a metal base (member under treatment  30 ). After the metal base (member under treatment  30 ) is machined to have predetermined dimensions, undergoes acid washing for removing contaminants and impurities on the surface. 
     During the acid washing of the metal base (member under treatment  30 ), the member under treatment  30  is fixed on the jig base  20  by the bolt B and the tapered implant  10 , as illustrated in FIG.  2 . Then, the member under treatment  30  is immersed in an acid solution to remove contaminants on the surface of the member under treatment  30 . Here, assuming that the dimension of an internal opening  32  formed through the member under treatment  30  must be finished at a high accuracy (for example, the diameter of the hole is 10-0.05 mm), if the inner face of the hole  32  is washed with an acid solution, the dimension accuracy of the hole cannot be maintained at a predetermined level, so that a masking member  40  is used in order to prevent the inner face of the hole  32  from getting into contact with the acid solution. 
     As the acid washing of the member under treatment  30  is completed, the member under treatment  30  as mounted on the jig base  20  as illustrated is transported to a plating apparatus to form a plated film M on the surface of the member under treatment  30 . In this event, the masking member  40  prevents a plated film from being formed on an end  34  of the member under treatment  30  as well as prevents a plated film from being formed on the inner surface of the hole  32  of the member under treatment  30 . The end  34  of the member under treatment  30  is later formed into a flange which serves as a mount when the diamond grind stone is mounted to an apparatus, so that the masking member  40  additionally prevents the plated film from being formed on this portion. 
     The jig base  20  may have an arbitrary size. For example, assuming that the jig base  20  is in the shape of a square having a side of 500 mm and the member under treatment  30  has a diameter of approximately 90 mm, a total of 25 tapered implants  10  arranged in five rows and five columns have been previously embedded in the jig base  20 , so that 25 members under treatment  30  can be simultaneously subjected to acid washing, plating or the like. 
     Next, the structure of the tapered implant  10  will be described with reference to FIGS. 3 and 4. 
     FIG. 3 is a perspective view illustrating the structure of the tapered implant  10 , and FIG. 4 is a cross-sectional view illustrating the structure of the tapered implant  10 . 
     As illustrated in FIG. 3, the tapered implant  10  is comprised of a tapered portion  14  having an external appearance of a circular truncated cone shape, and a projecting portion  16  formed at a diverging end of the tapered portion  14 . Also, the illustrated tapered implant  10  is formed with a female thread  12  on its inner face. The center axis of the female thread  12  is coincident with the axis of the tapered portion  14 . Therefore, the female thread  12  is an extension which extends in the axial direction of the tapered portion  14 . 
     Assume herein that the outer diameter of a screw with a male thread engaged with the female thread  12  is d 0 ; the outer diameter of the diverging end of the tapered portion  14 , i.e., the largest diameter of the tapered portion  14  is d 1 ; the outer diameter of the projecting portion  16  is d 2 ; and the width of the projecting portion  16  is d 3 . Assume also that the length of the tapered implant  10  is L; and the thickness of the projecting portion  16  is t. 
     When the tapered implant  10  is manufactured, for example, in correspondence to a male screw of M 6 , the dimensions and shapes of the respective portions are as follows. When the male screw inserted into the tapered implant  10  in engagement with the female thread formed thereon is M 6 , the outer diameter d 0  of the male screw is 6 mm; the largest diameter d 1  of the tapered portion  14  is 10 mm; the outer diameter d 2  of the projecting portion  16  is 12 mm; and the width d 3  of the projecting portion  16  is 1 mm. Also, the length L of the tapered implant  10  is 12 mm; an the thickness t of the projecting portion  16  is 1 mm. Further, a tapering ratio of the tapered portion  14  is chosen to be 1/20. It should be noted that the tapered implant corresponding to the male screw of M 6  is not limited to the dimensions mentioned above, but may be a slightly thicker tapered implant with an increased outer diameter d 2  of the projecting portion  16  and an increased largest diameter d 1  of the tapered portion  14 , or, on the contrary, may be a slightly thinner tapered implant. 
     Next, a process for embedding the tapered implant  10  into the jig base  20  in accordance with the embodiment will be described with reference to FIGS. 5A to  5 D. 
     FIGS. 5A to  5 D illustrates a sequence of steps in the process for embedding the tapered implant into the jig base. 
     As illustrated in FIG. 5A, a form drill D is used to pierce a hole through the resin made jig base  20  for inserting the tapered implant thereinto. 
     By the piercing illustrated in FIG. 5A, the jig base  20  is formed with a hole  22  as illustrated in FIG.  5 B. The hole  22  is comprised of a tapered hole portion  22 T and a stepped hole portion  22 S. The tapered implant  10  is inserted into the hole  22 . As previously described with reference to FIG. 1 or  2 , the tapered implant  10  is comprised of the tapered portion  14 , the projecting portion  16 , and the female thread  12 . 
     The tapered portion  14  of the tapered implant  10  is dimensioned to slightly close fit into the tapered hole portion  22 T of the hole  22  into which it is fitted. Specifically, as illustrated in FIG. 5C, when the tapered implant  10  is dropped into the hole  22 , the lower face of the projecting portion  16  is lifted off the stepped hole portion  22 S of the hole  22 . The amount F by which the lower face of the projecting portion  16  is lifted off the stepped hole portion  22 S of the hole  22  is herein referred to as the “close fit margin.” 
     In the state illustrated in FIG. 5C, the upper face of the projecting portion  16  of the tapered implant  10  is struck using a striking hammer to sink the tapered implant  10  into the hole  22  of the jig base  20 , causing the projecting portion  16  to hit on the stepped hole portion  22 S and stop. 
     Since the tapered hole portion  22 T of the hole  22  is in engagement with the tapered portion  14  of the tapered implant  10 , the axial center of the hole  22  is coincident with the axial center of the tapered implant  10 . Therefore, by forming the hole  22  so as to be orthogonal to the surface of the jig base  20 , the axial center of the tapered implant  10  is oriented orthogonal to the surface of the jig base  20 . With the axial center of the female thread  12  formed in the tapered implant  10  coincident with the axial center of the tapered portion  14  of the tapered implant  10 , the center axis of the female thread  12  can be readily oriented orthogonal to the surface of the jig base  20 . 
     With the projecting portion  16  formed in an upper portion of the tapered implant  10 , the lower surface of the projecting portion  16  of the tapered implant  10  hits on the stepped hole portion  22 S and stops. If the projecting portion  16  were not provided, the tapered implant  10  would creep into the hole  22 , causing the hole  22  of the jig base  20  to considerably deform since the jig base  20  made of an aluminum alloy is softer than the tapered implant  10  made of stainless steel. On the contrary, the tapered implant  10  formed with the projecting portion  16 , as this embodiment, can prevent the tapered implant  10  from creeping into the hole  22  and accordingly prevent the hole  22  from deforming. 
     In a state illustrated in FIG. 5D, since the tapered implant  10  is held by the jig base  20  with a friction force, it is necessary to accurately manage the close fit margin F for the hole  22 . To this end, it is important to accurately machine the tapered portion  14  of the tapered implant  10  and simultaneously machine the tapered hole portion  22 T of the hole  22  and the stepped hole portion  22 S. The accuracies of two blades, i.e., a tapered portion machining blade and a stepped portion machining blade of the form drill D, for simultaneously machining the tapered hole portion  22 T and the step portion  22 S, will dominate the accuracy of the close fit of the tapered implant  10 . Specifically, since the tapered implant  10  is struck into the hole as it enlarges the hole  22 , and stops when the projecting portion  16  comes in contact with the stepped hole portion  22 S of the hole  22 , the tapered hole portion  22 T and the stepped hole portion  22 S of the hole  22  must be machined at a high accuracy. 
     It is also necessary to accurately manage the close fit margin F of the tapered implant  10  in order to provide a stable fastening structure. For example, in a tapered implant manufactured in correspondence to a male screw of M 6 , assume that the largest diameter d 1  of the tapered portion  14  is 10 mm, and the tolerance is in a range of +0.02 mm to +0.04 mm for this largest diameter d 1 . Therefore, an average tolerance is +0.03 mm. Assume also that the largest diameter D 1  of the tapered portion machining blade DT of the form drill D for forming the tapered hole portion  22 T of the hole  22  is 6 mm, and the tolerance is in a range of −0.01 mm to +0 mm for this largest diameter D 1 . Therefore, an average tolerance is −0.005 mm. In this way, the largest diameter of the tapered hole portion  22 T of the hole  22  formed by the tapered portion machining blade DT is chosen to be larger by 0.035 mm than the largest diameter d 1  of the tapered portion  14  of the tapered implant  10 . Assume herein that the tapering ratio of the tapered portion machining blade DT of the form drill D and the tapering ratio of the tapered portion  14  of the tapered implant  10  are both chosen to be 1/20. As a result, the close fit margin F is calculated to be 0.7 mm (=0.035 mm×20). In other words, the close fit margin F of the tapered implant  10  for the hole  22  can be accurately managed by accurately machining the tapered portion  14  of the tapered implant  10  and simultaneously machining the tapered hole portion  22 T and the stepped hole portion  22 S of the hole  22 . 
     With the tapering ratio fixed at 1/20 for the tapered portion  14  of the tapered implant  10  and the tapered hole portion  22 T of the hole  22  formed through the jig base  20 , the largest diameters d 1  of the tapered portion  14  of the tapered implant  10  was varied to alter the close fit margin F for the tapered portion for testing a situation in which the tapered implant would be struck into the hole  22 . The result of the testing shows that while the close fit margin F for the tapered portion  14  was altered from 0.01 to 0.07 mm, the tapered implant  10  could be readily struck into the hole  22  in any case, and was held extremely satisfactorily without rotations. Even when a male screw was fastened into the tapered implant  10 , the male screw could be firmly fastened without causing the tapered implant  10  to rotate. 
     In order for the tapered implant  10  to be readily struck into the jig base  20  and reliably held therein after it has been embedded, a tapering angle must be smaller than at least a friction angle. While the tapering ratio of 1/20 is a significantly favorable value in consideration of easiness of striking the tapered implant  10  into and holding the same in the jig base  20 , the tapering ratio in a range of 1/50 to 1/10 may be preferably applied, and the tapering ratio up to approximately 1/7 to 1/6 could also be applied in some cases. However, a larger tapering ratio causes an increased striking force, and it was observed that with the tapering ratio exceeding 1/6, the tapered implant  10  once struck into the jig base  20  was bounced out. 
     Next, a method of recovering the jig base  20  having the tapered implant  10  embedded therein in accordance with the embodiment will be described with reference to FIGS. 6 to  10 . 
     As described with reference to FIG. 1, the tapered implant  10  is embedded in the jig base  20 . The tapered implant  10  may become more loosely fit in the jig base  20  due to the influence of a residual stress produced near the hole  22  when the hole  22  is pierced into the jig base  20 , a residual stress which remains in the jig base  20  when the tapered implant  10  is struck into the hole  22 , and so on, together with aging changes. Also, as described with reference to FIG. 2, the member under treatment  30  is mounted on the jig base  20  with the bolt B and the tapered implant  10 . Since the jig base  20  is transported with the member under treatment  30  mounted thereon, the tapered implant  10  is applied with a load of the m ember under treatment  30 , causing in some cases a deformation of the hole  22  of the jig base  20  to reduce the close fitness of the tapered implant  10  to an insufficient level. In such a case, the tapered implant  10  is removed from the jig base  20 , the hole  22  is machined again, the deformed tapered port ion  22 T is removed from the hole  22 , and then the original tapered implant  10  is again struck into the jig implant  20 , thereby making it possible to reuse the jig base  20 . 
     First, a process for the removal of the tapered implant will be described with reference to FIGS. 6 and 7. 
     FIGS. 6A to  6 E illustrate a sequence of steps in the process for removing the tapered implant using a drill press or a dedicated machine. 
     As illustrated in FIG. 6A, the jig base  20  having the tapered implant  10  embedded therein is placed on a bearer RD. 
     Next, as illustrated in FIG. 6B, an extracting rod DB is set at a chuck CH at the tip of the drill press or dedicated machine. 
     Next, as illustrated in FIG. 6C, the chuck CH at the tip of the drill press or dedicated machine is lowered to press the leading end of the extracting rod DB against the reduced end (opposite side of the end at which the projecting portion is formed) of the tapered implant  10 . 
     Next, as illustrated in FIG. 6D, the extracting rod DB is further lowered to extrude the tapered implant  10  embedded in the jig base  20  so that the tapered implant  10  is removed from the jig base  20 . 
     Next, as illustrated in FIG. 6E, the extracting rod DB is elevated, and the jig base  20  is also elevated, resulting in the extracted tapered implant  10  remaining on the bearer RD. 
     Next, a process for manually removing the tapered implant from the jig base will be described with reference to FIGS. 7A to  7 E. 
     As illustrated in FIG. 7A, the jig base  20  having the tapered implant  10  embedded therein is placed on the bearer RD. 
     Next, as illustrated in FIG. 7B, the extracting rod DB is prepared above the tapered implant  10 . 
     Next, as illustrated in FIG. 7C, the leading end of the extracting rod DB is pressed against the reduced end (opposite side of the end at which the projecting portion is formed) of the tapered implant  10 . 
     Next, as illustrated in FIG. 7D, a force is applied to the end of the extracting rod DB using a hammer or the like to extrude the tapered implant  10  embedded in the jig base  20 , thereby removing the tapered implant  10  from the jig base  20 . 
     Next, as illustrated in FIG. 7E, the extracting rod DB is removed from the jig base  20 , and the jig base  20  is elevated, resulting in the extracted tapered implant  10  remaining on the bearer RD. 
     Next, a process for machining the tapered portion in the hole for recovery will be described with reference to FIGS. 8A to  8 D. 
     FIGS. 8A to  8 D illustrate a sequence of steps in the process for machining the tapered portion of the hole extending through the jig base for recovery. 
     As illustrated in FIG. 8A, upon completion of the operation for removing the tapered implant in FIG. 6 or  7 , the hole  22  remains in the jig base  20 . In the hole  22 , particularly, a portion of the tapered portion  22 T often suffers from deformation. To restore the hole  22 , a form drill D is prepared. The form drill D, which is the same as that used to form the hole  22  as described in connection with FIG. 5A, has a tapered blade DT in the direction of the tip. 
     Next, as illustrated in FIG. 8B, the form drill D is lowered to press a step portion DS of the drill D against the step portion  22 S of the hole  22  to position the drill D in the hole  22 . 
     Next, as illustrated in FIG. 8C, the form drill D is lowered by a predetermined amount Wi from the position indicated in FIG. 8B to cut the hole  22  with the drill D. 
     FIG. 8D illustrates how the tapered implant  10  is embedded again in a hole  22 ′ restored by the cutting described with reference to FIG.  8 C. The tapered implant  10  is embedded at a position deeper than the original position by a depth WI. An investigation on the secondary cut amount W 1  revealed that a deformed hole was solved sufficiently only by cutting approximately 0.1 mm, so that the newly embedded tapered implant was held in the hole with a sufficient strength. Assuming for example, that the jig base  20  has a plate thickness D 1  of 20 mm and the tapered implant  10  has a length L of 12 mm, a permitted amount for the cutting to prevent the end of the tapered implant  10  from protruding from the surface of the jig base  20  is limited to 8 mm (20−12 mm), so that if the amount of secondary cutting is chosen to be 0.1 mm, the jig base  20  can be reused  80  times by the secondary cutting. 
     Next, a process for embedding the tapered implant will be described with reference to FIGS. 9 and 10. 
     FIGS. 9A to  9 E illustrate a sequence of steps in the process for embedding the tapered implant using a drill press or a dedicated machine. 
     First, as illustrated in FIG. 9A, the jig base  20  and the tapered implant  10  are prepared. 
     Next, as illustrated in FIG. 9B, the tapered implant  10  is inserted into the hole  22  of the jig base  20 . With the tapered portion of the implant  10  in contact with the tapered portion of the hole  22 , the tapered implant  10  is carried on the jig base  20  such that the projecting portion  16  of the tapered implant  10  is lifted off by a close fit margin F above the step portion  22 S of the hole  22 . 
     Next, as illustrated in FIG. 9C, an embedding jig IT is set in the chuck CH at the tip of the drill press or dedicated machine. 
     Next, as illustrated in FIG. 9D, the chuck CH at the tip of the drill press or dedicated machine is lowered to press the leading end of the embedding jig IT against the projecting portion  16  of the tapered implant  10 . 
     Next, as illustrated in FIG. 9E, the embedding jig IT is further lowered to embed the tapered implant  10  deep into the hole  22  of the jig base  20 . 
     Next, a process for manually embedding the tapered implant into the jig base will be described with reference to FIGS. 10A to  10 E. 
     First, as illustrated in FIG. 10A, the jig base  20  and the tapered implant  10  are prepared. 
     Next, as illustrated in FIG. 10B, the tapered implant  10  is inserted into the hole  22  of the jig base  20 . With the tapered portion of the implant  10  in contact with the tapered portion of the hole  22 , the projecting portion  16  of the tapered implant  10  is carried on the jig base  20  such that the projecting portion  16  of the tapered implant  10  is lifted off by a close fit margin F above the step portion  22 S of the hole  22 . 
     Next, as illustrated in FIG. 10C, a guide G having a throughhole extending through the center thereof, and a press-fit jig IT′ are prepared. 
     Next, as illustrated in FIG. 10D, the guide G is set on the tapered implant  10 , and the press-fit jig IT′ is inserted into the central throughhole of the guide G. 
     Next, as illustrated in FIG. 10E, the top of the press-fit jig IT′ is struck with a hammer or the like to embed the tapered implant  10  into the hole  22  of the jig base  20 . 
     It should be noted that in the example illustrated in FIGS. 8A to  8 D, when the same form drill is used for the first hole machining and for the hole recovery machining, an additional form drill need not be provided. Alternatively, however, the jig base may be formed with a hole having a larger diameter using another form drill having a larger diameter than the form drill which is used for first machining the hole. In this event, a tapered implant struck into the hole should have a larger outer diameter conforming to the recovered hole, though a female thread formed on the inner face is the same as that of the tapered implant which has been previously inserted into the previous hole. 
     In this way, it is possible to improve a mounting strength of the tapered implant when it is embedded in the jig base. 
     While the foregoing embodiment has been described for the structure for mounting a member under treatment on a jig base, this embodiment may be similarly applied to a structure for fixing a jig base within a treatment facility which uses chemicals. Also, this embodiment may be applied to a structure for fixing a member such as a motor within a treatment facility which uses chemicals. Further, this embodiment may be applied to a mounting structure for a member coupled to the body of a treatment facility, such as an open/close lid of a treatment facility. 
     As described above, according to the foregoing embodiment, a portion of members can be readily replaced in a treatment facility using chemicals. 
     Next, the structure of an apparatus for installing a material which is processed by using chemicals according to another embodiment will be described with reference to FIG.  11 . 
     FIG. 11 is a cross-sectional view generally illustrating the structure of a member coupling device according to another embodiment of the present invention. 
     The embodiment of FIG. 11 differs from the embodiment of FIG. 2 in that a tapered implant  10 A in the former comprises a bolt  18  such that a nut N is fixed by a leading end portion thereof in engagement with the nut N. 
     A member under treatment  30  is placed on a jig base  20  which has the tapered implant  10 A previously embedded therein such that the bolt  18  is inserted though a hole  32  of the member under treatment  30 . 
     Next, a masking member  40  is carried on the member  30  such that a hole  42  of the masking member  40  is inserted on the bolt  18 . Further, the Nut N serving as a fastening member is screwed onto a leading end portion of the bolt  18 , so that the member under treatment  30  can be mounted to the jig base  20  by the screw coupling of the bolt  18  of the tapered implant  10 A with the nut N. Since the bolt  18  forming part of the tapered implant  10 A serves as a guide for the member under treatment  30 , the member under treatment  30  can be readily carried on the jig base  20 . 
     According to this embodiment, since the tapered implant  10 A can be readily removed, the jig base  20  can be reused. 
     As will be appreciated from the foregoing, the preferred embodiments of the present invention permit a portion of members to be readily replaced in a treatment facility which uses chemicals.