GB2177470A

GB2177470A - Pipe joining apparatus

Info

Publication number: GB2177470A
Application number: GB08612452A
Authority: GB
Inventors: Masayuku Takatsu; Shoji Naganuma; Minoru Hanazono
Original assignee: Tokyu Construction Co Ltd
Current assignee: Tokyu Construction Co Ltd
Priority date: 1985-06-29
Filing date: 1986-05-22
Publication date: 1987-01-21
Also published as: JPH0239745Y2; GB8612452D0; GB2177470B; JPS628490U

Abstract

Pipe joining apparatus comprises an inserter 8 which is provided for pushing in an O ring between the joints of a previously laid pipe 1 and a pipe to be fitted thereto, an actuating arm 11 which rotates with a counterforce gained from the flange 1b of the pipe 1, and a linkage 14 which is connected between the arm 11 and the inserter 8. When the arm 11 is rotated, the linkage draws the inserter 8 along the axis of the pipes guided along rods 9 which pass through bolt holes 1b' of the flange 1b. <IMAGE>

Description

SPECIFICATION Pipe joining apparatus The present invention relates to an apparatus for joining tubular bodies such as gas pipes.

As is shown in Figure 1, tubular bodies such as gas pipes are joined together generally in such a manner that one end portion 2a of a pipe 2 to be fitted is inserted into the expanded-diameter end portion 1a of a previously-laid pipe 1, and in the state in which a back-up ring 3, an 0 ring 4 and a square rubber 5 are put in between these end portions 1a and 2a so that airtightness in secured between them, the flange 1b of said previously-laid pipe 1 and a fastening flange 6 are coupled together integrally by a bolt 7. Therefore it is necessary to push in the 0 ring 4 by using an inserter after the insertion of the back-up ring. When a load is not applied uniformly to the 0 ring 4 on occasion, a prescribed final torque (e.g. 900 kg.cm) can not be obtained, and when the application is incomplete, readjustment is required.

A conventional inserter is so constructed that a bolt is inserted through it and a bolt hole 1b' of the flange 1 b of the previously-laid pipe 1 and, when this bolt is tightened, the 0 ring etc. are pushed in thereby. Accordingly, diagonally-positioned bolts out of those disposed on the flange must be tightened alternately for such uniform pushing-in as de scribed above, and this operation has disadvantages that it necessitates hard labor and long time an4, moreover, tends to be omitted or cause an incomplete junction.

The present invention, which is designed to eliminate the aforesaid prior-art disadvantages, aims to furnish a new pipe joining apparatus which enables the curtailment of labour and time for the operation of pushing in the 0 ring by the inserter and the reduction of readjusting work required by imperfect fitting.

A description will be made hereunder on embod iments of the present invention with reference to drawings, in which: Figure 1 is a half sectional view showing the joined state of pipes; Figure 2A is a front view of one embodiment of a pipe joining apparatus of the present invention; Figure 2B is a side view thereof; Figure 2C is a top view of a section taken along a line 11C - 11C of Figure 2B; Figure 3A is a perspective view of a second em bodiment; Figure 3B is a top view thereof; Figure 4 is a perspective view of a third embodi ment; Figure 5 is a perspective view of a fourth em bodiment; Figure 6 is an illustration of the joining operation by a double link mechanism; Figure 7 is a side view of a fifth embodiment; Figure 8A is a side view of a sixth embodiment; Figure 8B is a front view thereof;; Figures 9A and 9B are illustrations of the state of operation; Figure lOA is a side view of a seventh embodiment; Figure lOB is a view of this embodiment seen in the direction of an arrow I of Figure 10A; Figure lOC is a view thereof seen in the direction of an arrow II of Figure 10A; Figure lOD is a view of another embodiment of a support; and Figures 11(A) and (B) are diagrams for illustrative comparison in terms of a push-in force and an upward force of an inserter.

In Figures 2A to 2C, numeral 8 denotes an inserter, which is divided into semi-circular parts positioned on the right and left of a connecting pin 8a and is joined into a circle by a joining pin 8b when it is put on a pipe 2 to be fitted. A projection 8' is formed on each of the opposite lateral sides of said inserter 8, and a guide hole 8c is bored therein so that a slide rod 9 can be inserted therethrough. Said slide rod 9 is inserted also through a bolt hole 1b' of the flange 1b of the aforesaid previously-laid pipe 1, while a support 10 is put from outside on the end portion of the slide rod 9 projecting from said bolt hole 1b'.

On the outside of said support 10, the lower end portion of an actuating arm 11 is fitted pivotally so that the acutating arm 11 can be rotated around said portion working as a supporting point. The upper portions of right and left actuating arms 11 are bent inward mutually and held integrally in a holder 12. A grip 13 is attached to said holder 12.

One end portion of a linkage 14 is fitted pivotally to the an intermediate portion of the aforesaid actuating arm 11, while the other end portion of said linkage 14 is attached pivotally on the end surface of the projection 8' of the aforesaid inserter 8 by a stud knob 15, thus constituting a three-joint slide mechanism together with the slide rod 9 and the actuating arm 11.

Since the pipe joining apparatus of the present embodiment is constructed as described above, first the inserter 8 is opened in the state in which the stud knob 15 and the joining pin 8b are removed therefrom, and then is fitted to the pipe 2 to be fitted when an operation to push in an 0 ring 4 is executed. Next, the aforesaid slide rod 9 is inserted through the bolt hole 1 b' of the flange 1 b of the previously-laid pipe 1 and the guide hole 8c of the inserter 8 sequentially, while the stud knob 15 is screwed into the end of the projection 8' of the inserter 8 and set as shown in the figure.

When the grip 13 is handled to rotate the actuat ing arms 11 in the direction of an arrow of Figure 28 in this state, each of said actuating arms 11 abuts against the aforesaid flange 1b through the intermediary of the support 10 located at the base end portion thereof and gains a conunterforce from said flange, while pulling the inserter 8 in the direction of an arrow through the intermediary of the aforesaid linkage 14. While said inserter 8 slides along the slide rod 9, the pushin members 8d thereof get into the expanded-diameter end portion 1a of the previously-laid pipe 1, so as to push the 0 ring 4 inward.When the 0 ring 4 is hard to push only by pulling or pushing the grip 13 as described above, a repeated operation of pushing and pulling said grip 13, or a knocking to push in the 0 ring by the use of a reaction, when occasion demands, may be done for accomplishing the purpose.

When the push-in operation is completed, the stud knob 15 is removed, the slide rod 9 is drawn out, and further the joining pin 8b is removed, so as to removed the inserter 8 from the pipe 2 to be fitted. Thereafter, a square rubber 5 and a fastening flange 6 are moved to a joining position, and the fastening flange 6 is tightened finally by a tightening bolt 7, whereby the joining is completed.

Figures 3A and 3B shows another embodiment of the invention, which differs from the foregoing embodiment in that the end portion of the aforesaid linkage 14 is made to engage with the projection 8' of the inserter 8 by an engaging piece 16 instead that said end portion is connected to said projection 8' by the stud knob 15 in the latter. In said engaging piece 16 a hole 16a is bored so that the aforesaid slide rod 9 can be inserted therethrough, and thus the engaging piece 16 is prevented from disengaging from the projection 8'.

Therefore the fitting and removal of the linkage 14 can be performed rapidly according to the present embodiment, thus an advantage of an efficient operation being attained.

Figure 4 shows still another embodiment of the invention, which is so designed that the space between the right and left actuating arms 11 can be altered freely by using an adjust frame 17 and the arms 11 can be fixed simply by adjust pins 17a, thus giving an advantage of enabling the free adjustment of said space in accordance with various diameters of pipes and the constant employment of the apparatus in the optimum state. It should be mentioned, in this connection, that the space between the actuating arms 11 can be adjusted freely in the holder 12 also in the first embodiment.

Figure 5 shows yet another embodiment of the present invention, in which the linkage 14 of the foregoing embodiment is formed to have substantially the same size as the actuating arm 11 and a double-threaded-end jack 18 disposed between the linkages and the arms. Since the pushin operation is performed by this jack, a very large pushing force can be obtained by the present apparatus.

Therefore, it is suitable specifically for a pipe of large diameter or the like.

Although each one point on both sides of the inserter 8 serves as a working point in any one of the above-described embodiments, the present invention is not limited to this construction, and another construction in which a plurality of points, two or three points, for instance, serve as working points may be adopted. In this case, it is preferable that the working points are disposed symmetrically on the right and left sides.

As is shown in Figure 6, for instance, the same link mechanism (comprising an actuating arm 11' and a linkage 14') with the one comprising the aforesaid acutating arm 11 and linkage 14 is formed above and parallel to the latter, the upper ends of the actuating arms 11 and 11' are coupled together by a grip lever 19, supports 10 and 10' are made to abut against the flange 1 b, while the end portions of the linkages 14 and 14' are made to engage with the inserter 8 by engaging pieces 16 and 16' respectively. 8y gripping the grip lever 19 at its appropriate position by hand and pulling it from the position indicated by a solid line into the state indicated by a hypothetical line in the above-described construction, the inserter 8 can be pushed in at two points on both right and left sides by equal forces simultaneously.In the case when a sufficient force can not be exerted only by gripping the grip lever 19, a device may be used in which a sleeve (not shown in the figure) is fitted movably to said grip lever 19 and an appropriate rod is so put therein as to be gripped to push in the inserter.

The slide rod 9, which is inserted through the flange 1 b and the guide hole 8c of the inserter 8 in any one of the above-described embodiments, may be dispensed with. Since the support 10, the engaging piece 16, etc. can be moved freely in the circumferential direction of the flange 1b and the inserter 8, in this case, the grip 13 can be rotated to the right and left around the pipe so that the inserter can be pushed in moderately without wrenching.

For fitting the aforesaid linkage 14 pivotally to the inserter 8, another means may be taken in which a cut portion 14a formed in the linkage 14 is made to engage with a pin 8" which is provided on the lateral side of the inserter 8 as shown in Figure 7. This means enables rapid fitting and removal of the linkage 14, thus giving an advantage of improving a working efficiency.

Figures 8A and 8B show another embodiment of the present invention, in which numeral 21 denotes an inserter which is divided into semicircular parts positioned on the right and left of a connecting pin 22 and is joined into a circle by a joining pin 23 when it is fitted to the pipe 2 to be fitted. Two guide holes 21a are bored in the upper and lower positions on each of the opposite lateral sides of said inserter 21 so that a slide rod 24 can be inserted slidably through each of them.

Said slide rod 24, which can be inserted also through a bolt hole of the flange 1 b of the previously-laid pipe 1, is planted at its base end into an arc-shaped support 25.

To the outer end portion of said support 25 the lower end portion of an actuating arm 26 is fitted pivotally so that it serves as a supporting point 26a for the actuating arm 26 to rotate around it. The upper portions of the right and left actuating arms 26 are bent inward mutually and formed into one integral body, and a handle 27 is fitted to the central portion of this body. To an intermediate portion of the actuating arm 26 in close proximity to the aforesaid supporting point 26a, the base end portion of a linkage 28 is attached pivotally and rotatably by a pivotally-fitting member 28a.

The aforesaid linkage 28 has two cut engaging portions 28b and 28c which are so formed as to engage selectively with an engaging pin 29 provided on the lateral side of the aforesaid inserter 21. The aforesaid actuating arm 26 is also fitted with a pressure spring 30, which actuates the linkage 28 counter-clockwise elastically and ensures the firm engaged state of the aforesaid cut engaging portion 28b or 28c with the engaging pin 29.

Since the pipe joining apparatus of the present embodiment is constructed as described above, first the cut engaging portion 28b or 28c of each linkage 28 is disengaged from the engaging pin 29, the joining pin 23 is pulled out to open the inserter 21 to the right and left and then the inserter is put on the pipe 2 to be fitted, when the operation to push in an 0 ring is executed.

Next, the slide rods 24 are inserted through the bolt holes of the flange 1b of the previously-laid pipe 1 and the guide holes 21a of the inserter 21 sequentially, while the cut engaging portions 28b of the linkage 28 are made to engage with the engaging pins 29 and set as shown in Figure 8A.

When the handle 27 is gripped and thereby the actuating arms 26 are rotated in the direction of an arrow of Figure 9A in this state, said actuating arms 26 abut against the aforesaid flange 1 b through the intermediary of supports 25 positioned at the base end portions thereof and gain a counterforce therefrom in this state, while pulling in the inserter 21 from the position indicated by a hypothetical line to the position indicated by a solid line through the intermediary of the aforesaid linkages 28. While said inserter 21 slides along the slide rods 24, the push-in members 21b thereof get into the expanded-diameter end portion 1a of the previously-laid pipe 1, so as to push the 0 ring inward.

When the handle 27 is pushed back, subsequently as indicated by a hypothetical line in Figure 9B, each engaging pin 29 of the inserter 21, which is located near to the supporting point 26a of the acutating arm 26 since the inserter 21 is pulled in somewhat to the right by the foregoing operation, disengages from the cut engaging portion 28b of the linkage 28 and engages with the cut engaging portion 28c positioned nearer to the pivotally-fitting member 28a.

When the handle 27 is pulled again in the direction of an arrow of Figure 9B to the position indicated by a solid line in this state, the inserter 21 is pulled in further, so as to push the 0 ring into the depth of the expanded-diameter end portion 1 a of the previously-laid pipe 1.

When the push-in operation is completed, the cut engaging portion 28c of each linkage 28 is disengaged from the engaging pin 29, while the joining pin 23 is pulled out to open the inserter 21 and remove the same from the pipe 2 to be fitted, and thereafter a fastening flange is tightened appropriately and finally by a tightening bolt, whereby the joining is completed.

Figures 10A to 10C show still another embodiment of the present inventin, in which numeral 31 denotes an inserter which is divided into semicircular parts positioned on the right and left of a connecting pin 32 and is joined into a circle by a joining pin 33 when it is fitted to the pipe 2 to be fitted. On each of the opposite lateral sides of said inserter 31 two guide holes 31a are bored in the upper and lower positions so that a slide rod 34 can be inserted slidably through each of them.

Said slide rod 34 is inserted also through a bolt hole 1 b' of the flange 1 b of the previously-laid pipe 1, while the base end portion thereof is planted into an arc-shaped support 35 (see Figure 10c). In the case when the bolt holes 1 b' of the flange 1 b of the previously-laid pipe 1 are disposed in oblique positions at an angle of 45 degrees respectively, for instances, the supports 35 are changed in the shape as shown in Figure 10D. Another design may be adopted, in this connection, in which said supports 35 are formed in extension as indicated by chain lines and two slide rods on each of the right and left sides are inserted through the upper and lower bolt holes 1b' respectively.

To the outer end portion of said support 35 the lower end portion of an actuating arm 36 is attached pivotally so that it serves as a supporting point 36a for the arm 36 rotating around it. Said supporting point 36a is deviated down from the position of the central axis C of the aforesaid previously-laid pipe 1. The upper portions of the right and left actuating arms 36 are bent inward mutually and formed into one integral body, and a handle 37 is fitted to the central portion of this body.

To an intermediate portion of each actuating arm 36 the base end portion of a linkage 38 is attached pivotally and rotatably at a pivotally fitting member 38a.

Said pivotally-fitting member 38a is deviated down from the position of the central axis C of the aforesaid previously-laid pipe.

The aforesaid linkage 38 have a cut engaging portion 38b which is so formed as to engage with an engaging pin 39 provided on the lateral side of the aforesaid inserter 31. The aforesaid actuating arm 36 may be fitted with a pressure spring (not shown in the figure) which actuates the linkage 38 counter-clockwise elastically and ensures the firm engaged state of the aforesaid cut engaging portion 38b with the engaging pin 39. In addition, said cut engaging portion 38b may be provided in a plurality.

Since the pipe joining apparatus of the present embodiment is constructed as described above, first the cut engaging portion 38b of each linkage 38 is disengaged from the engaging pin 29, the joining pin 33 is pulled out to open the inserter 31 to the right and left and then the inserter 31 is put slidably on the pipe 2 to be fitted, when the operation to push in the 0 ring 4 is executed.

Next, the slide rods 34 are inserted through the bolt holes 1 b' of the flange 1 b of the previouslylaid pipe 1, and the guide holes 31a of the inserter 31 sequentially, while the supports 35 are made to abut against the back of said flange 1 b, and the cut engaging portions 38b of the linkage 38 are made to engage with the engaging poins 39 and set as shown in Figure 10A.

When the handle 37 is gripped and thereby the actuating arms 36 are rotated in the direction of an arrow of Figure 10A in this state, said actuating arms 36 contact with the aforesaid flange 1 b through the intermediary of the supports 35 positioned at the base end portions thereof respectively and gain a counterforce therefrom in this state, while pulling in the inserter 31 in the direction of an arrow through the intermediary of the aforesaid linkages 38. While said inserter 31 slides along the slide rods 34, the push-in members 31b thereof get into the expanded-diameter end portion 1a of the previously-laid pipe 1, so as to push the O ring 4 inward.

When the push-in operation is completed, the cut engaging portion 38b of each linkage 38 is disengaged from the engaging pin 39, while the joining pin 33 is pulled out to open the inserter 31 and remove the same from the pipe 2 to be fitted, and thereafter a fastening flange is tightened appropriately and finally by a tightening bolt, whereby the joining is completed.

Figure 11 is an illustration for comparing a conventional appar atus in which the supporting point of the actuating arm is positioned on the central axis of a pipe with the apparatus of the present invention in which said supporting point is positioned below said central axis, in terms of a pushin force and an upward force. First, a mention will be made on the conventional apparatus shown in Figure 11 (A). When a force FDH at a point D of the handle is 20 Kg, a horizontai force FBH at the pivotally-fitting point B of the actuating arm and the linkage is FBH = FDH x (CD/B C). Given that CD is 500 mm and B C 64 mm therein, FBH = 20 x (500 / 64) = 156 Kg.

Morevoer, given that an angle ((X) formed between the linkage and the central axis of the pipe is 35 degrees, a component force of said FSH in the axial direction (AB) of the linkage is FAB = FBH-COSOL = 156 x Cos 35 = 128 Kg. Since this FAB is equal to the force acting in the same direction at a point A of the linkage, horizontal force FAX, i.e., a push-in force, at the point A is FAX = FAB Cosa = 128 x Cos 35 = 104.7 Kg, while an upward force FAV is FAV = FAB Sina = 128 x Din 35 =73.3 Kg.

In the apparatus of the present invention shown in Figure 11 (B), on the other hand, C D becomes longer by 30 mm than D C in the above-described conventional apparatus when the position of a supporting point C is lowered by about 30 mm from the central line without changing the position of the point D and the length of the actuating arm.

When FDH = 20 Kg, the same force as described above, is applied to the point D of the handle, accordingly, FBX = FDK x (CD / B C) = 20 x (530 / 64) = 166 Kg.

Since the point B is lowered with the lowering of the supporting point C, the angle CL becomes 18 and consequently FAB FBH-COSR =166 x Cos 18 = 158 Kg.

Therefore, the push-in force FAX at the point A is FAX = FABCOSCL = 158 x Cos 18" "150 Kg, and the upward force FAV = FAB-Sina = 158 x Sin 180 = 48.8 Kg.

Accordingly, the push-in force FAX becomes larger by 150 - 104.7 = 45.3 Kg, while the upward force FAV becomes smaller by as much as 73.3 48.8 = 24.5 Kg, and thus an improvement in this respect can be perceived.

Claims

1. A pipe joining apparatus comprising an inserter which is provided for pushing in an 0 ring between the joints of previously-laid pipe and a pipe to be fitted, an actuating arm which rotates with a counterforce gained from the flange of the previously-laid pipe, and a linkage which is connected between said actuating arm and the aforesaid inserter so that it forms a link mechanism with the actuating arm.

2. A pipe joining apparatus comprising an inserter which is fitted slidably to the pipe to be fitted and has a push-in member for pushing an O ring into the expanded-diameter end portion of the previously-laid pipe and a guide hole, a support which is provided with a slide rod to be inserted slidably through said guide hole and abuts against the back of the flange of the previously-laid pipe, and actuating arm which is fitted pivotally and rotatably to the outer end portion of said support, and a linkage which is attached pivotally to said actuating arm and has at least two cut engaging portions engaging pin of the aforesaid inserter.

3. A pipe joining apparatus comprising an inverter which is fitted slidably to the pipe to be fitted and has a push-in member for pushing an O ring into the expanded-diameter end portion of the previously-laid pipe and a guide hole, a support which is provided with a slide rod to be inserted slidably through said guide hole and abuts against the back of the flange of the previously-laid pipe, an actuating arm which is attached pivotally and rotatably to the outer end portion of said support and whose fulcrum is deviated downward from the position of the central axis of the aforesaid previously-laid pipe, and a linkage which is attached pivotally to said actuating arm in upward deviation from said postion of the central axis and has a cut engaging portion engaging with an engaging pin provided at the position of the central axis of the aforesaid inserter.

4. A pipe joining apparatus substantially as described herein with reference to the accompanying drawings.