WO1989008019A1

WO1989008019A1 - A tube-forming machine

Info

Publication number: WO1989008019A1
Application number: PCT/JP1988/000203
Authority: WO
Inventors: Shigeki Fujii; Yasuo Fujiki; Kenichi Morikawa; Shigenobu Motomura
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd
Priority date: 1986-08-27
Filing date: 1988-02-25
Publication date: 1989-09-08
Anticipated expiration: 1990-08-25
Also published as: JPH0729368B2; JPS6356432A

Abstract

A tube-forming machine into which a strip is fed and then curved around into a helical fashion to form a helical tube, said machine comprising a fixed circular frame (20), a plurality of swing arms (22) positioned in such a manner that one end of each of the swing arms is pivoted (21) on the fixed frame and the other end thereof is disposed as a free end inside of the fixed frame, each of the swing arms having a pin (31) or long hole (22a) in the middle portion thereof in the longitudinal direction of said swing arm, a plurality of pipe-forming rollers (50) that are rotatably supported by the free ends of the swing arms in such a manner that the rollers are positioned in a helical fashion on the outer side of a virtual cylinder having the same diameter as the helical tube, and a rotatable circular frame (30) that is rotatably positioned inside of the fixed frame, the rotatable frame having long holes (22a) or pins (31) that slidably engage the pins or long holes of the swing arms whereby the swing arms are simultaneously swung around the pivotal ends thereof by the rotation of the rotatable frame, wherein the strip is forced into the virtual cylinder formed by the rollers so as to allow the strip to be curved around into a helical convolution, resulting in a helical tube.

Description

SPECIFICATION A TUBE-FORMING MACHINE

Technical Field

This invention relates to a pipe-forming machine that can make helical pipes of a fixed diameter by the rolling of a strip of synthetic resin, etc., into a helix.

Background Art

Japanese Laid Open Patent Application No. 55- 61434 discloses a pipe-forming machine for the manufacture of pipes of synthetic resin. The pipe- forming machine rolls a strip into a helix, and the edges of the strip that come together after it is rolled ere attached to each other, resulting in a helical pipe. This machine can be used for the continuous manufacture of pipe in a narrow spaos. In reαent years, the inner surfaces of sewage pipes are being lined with inner pipes made of synthetic resin. However, it is not easy to introduce a long inner pipe into sewage pipes. In such circumstances, a pipe-forming machine is placed inside of a manhole that is connected with the end of such sewage pipes, so as to make helical pipes continuously. The helical pipe is gradually introduced inside the sewage pipe as an inner pipe.

In conventional pipe-forming machines, there are e number of pipe-forming rollers that ere arranged on the outer aide of the virtual cylinder formed thereby. A strip is gradually forced into the virtual cylinder formed by these rollers so as to allow the strip to be curved around into a helix. Each pipe-forming roller is placed on the surface of the virtual cylinder et e specific angle with respect to the axis of the said virtual cylinder so that the strip will be rolled into a helix. The strip is conveyed et right angles to the pipe-forming rollers.

The pipe-forming rollers of the pipe-forming machine that is disclosed in Japanese Laid Open Patent Application No. 55-61434 are supported on one side by a frame to which they are attached by means of a nut in a long hole. If the position in which the pipe-forming rollers are fixed is varied with respect to the long hole, it is possible to change the diameter of the virtual cylinder on the surface of which the pipe-forming rollers are placed. For this reason, when the diameter of the helical pipe to be made is changed, the nut that fixes the pipe-forming rollers must be loosened to change the positions of the rollers with respect to the long hole. When it is necessary to change the angle of each pipe-forming roller with respect to the surface of the virtual cylinder, in the same way, each nut must be loosened to decide on the position of each pipe-forming roller. When the width of the strip to be introduced into the pipe-forming machine is to be changed, the same procedure is necessary. The edges of the strip sometimes cannot be brought together and fastened together when the pipe-forming machine rolls the strip into a helical shape. This arises when there are errors in measurement of the strip et the time of the manufacture of the strip, when an outside force causes deformations in the strip, etc. In these ciroumstances, also, it is again necessary to loosen the nuts in the frame to which the pipe-forming rollers ere attached, and to adjust the position of the pipe-forming rollers with respect to the frame in the same procedure as before. This kind of procedure is extremely troublesome, because pipe-forming rollers are separately attached to the frame end thus it is necessary to decide on the positions of each pipe- forming roller.

The pipe-forming rollers receive a large amount of force when the strip is being forcibly bent into e curve by coming into contact with the pipe- forming rollers that are supported on one side by the frame. For this reason, it is necessary that the pipe- forming rollers be supported strongly by the frame.

Disclosure of Invention

The pipe-forming machine of this invention, which overcomes the above-discussed end numerous other disadvantages end deficiencies of the prior art, is a machine into which a strip is fed and then curved around into a helical fashion to form a helical tube, said machine comprising a fixed circular frame, e plurality of swing arms positioned in such a manner that one end of each of said swing arms is pivoted on said fixed frame and the other end thereof is disposed as a free end inside of the fixed frame, each of said swing arms having a pin or long hole in the middle portion thereof in the longitudinal direction of said swing arm, a plurality of pipe-forming rollers that ere rotatably supported by said free ends of said swing arms in such a manner that said rollers are positioned in e helical fashion on the outer side of a virtual cylinder having the same diameter as said helical tube, and a rotatable circular frame that is rotatably positioned inside of said fixed frame, said rotatable frame having long holes or pine that slidably engage said pins or long holes of said swing arms whereby said swing arms are simultaneously swung around the pivotal ends thereof by the rotation of said rotatable frame, wherein said strip la forced into said virtual cylinder formed by said rollers so as to allow said strip to be curved around into a helical convolution, resulting in a helical tube.

In a preferred embodiment, an adjusting means for adjusting the amount of rotation of said rotatable frame is disposed between the fixed frame and the rotatable frame.

In e preferred embodiment, the oirculer frame is supported by a square frame so as to be concentric with respect to said square frame. A helix angle adjustment means is disposed in the space between the circular frame and the square frame, said helix angle adjustment means rotating said circular frame with respect to said square frame so as to move the ends of all of the pipe-forming rollers at the same time, so that the angles of the pipe-forming rollers to the axis of the virtual cylinder formed by all of the pipe-forming rollers are changed, whereby the pipe-forming rollers are brought to have a fixed helix engle with respect to the axis of the said virtual cylinder. Thus, the invention described herein makes possible the objectives of (1) providing a pipe-forming machine with which, when the width of a strip is changed or when the diameter of a helical pipe to be manufactured is changed, etc., it is possible to move all of the pipe-forming rollers as one, end thus, the diameter of the virtual cylinder formed by the pipe- forming rollers can be readily changed by means of a simple operation) end (2) providing a pipe-forming machine the equipment of which can all readily be made smaller, and thus, is suitable for use in the manufacture of inner pipes to line the inside surface of sewage pipes.

Brief Description of the Drawings

This invention may be better understood and its numerous objects and advantages will become apparant to those skilled in the art by reference to the accompanying drawings as follows:

Figure 1 is a front view showing a pipe-forming machine of this invention.

Figure 2 is a side view showing the pipe-forming machine of Figure 1 of this invention.

Figure 3 is a front view showing an enlarged part of the pipe-forming machine of Figure 1 of this invention. Figure 4 is a sectional view showing a means for the adjustment of helix angles at which pipe- forming rollers ere inclined to the axis of the virtual cylinder formed by the said rollers.

Figure 5 is a sectional view showing a means for adjusting the amount of rotation of a rotatable frame of this invention.

Best Mode for Carrying Out the Invention

The pipe-forming machine of this invention manufactures helical pipes continuously from a strip made of, for example, synthetic resin by the continuous rolling of the strip into a helix and by the fastening together of the edges of the strip that has been rolled into e helix where they come together.

The pipe-forming machine of this invention has, as shown in Figures 1 and 2, a rectangular parallelepiped frame 10 and a pair of fixed circular frames 20. The frame 10 has a pair of square frames 11 that face each ether. The square frames 11 are positioned so as to be approximately vertical. The square frames 11 contain the circular frames 20 in such a manner that they ere each concentric with the circular frames 20.

There are support rollers 12 in each corner of the square frame 11 in which one of the circular frames 20 is positioned. The support rollers 12 in the upper corners face the support rollers 12 in the lower corner. In the central part of the outside circumference of each support roller 12, there is a groove 12a that goes completely around the circumference (see Figure 4), and the grooves 12a mesh with the circular frame 20. The circular frame 20 is rotatably supported by the support rollers 12, end thus it is supported by the square frame 11. The other circular frame 20 is also supported in the same way by the other square frame 11.

Each circular frame 20 has, as shown in Figure 3, for example, twelve swing arms 22, the pivoting ends of which ere fixed to the frame 20 so as to pivot by fastening pins 21. The fastening pins 21 ere attached to the circular frames 20 so as to leave equal spaces therebetween. In the center of each swing arm 22, there is a long hole 22a opened to extend in the direction of the axis of each swing arm 22. The swing arms 22 are all equal in size.

In the free end of each swing arm 22, there is a free bearing 24 that makes use of, for example, bell bearings. The free bearing 24 of the swing arm 22 attached to one of the circular frames 20 face the free bearings 24 of the swing arms 22 attached to the other of the two circular frames 20, and in the space between the free bearings 24 that face each other, there is a roller shaft 51. Each pipe-forming roller 50 meshes with the roller shaft 51, and the pipe-forming roller 80 rotates as one with the roller shaft 51. The pipe-forming rollers 50 are arranged on the surface of a virtual cylinder. The pipe-forming rollers 50, by the rotation of either one or both of the circular frames 20 with respect to the square frame 11, are all brought to e fixed helix angle with respect to the axle of the virtual cylinder that they all form together. In the space between the square frame 11 and one of the circular frames 20, there is a helix angle adjustment means 40 (described below) for the purpose of adjustment of the helix angle at which the pipe-forming rollers 50 are inclined on the surface of the virtual cylinder to the axis of the said cylinder.

In each of the circular frames 20, there is fitted e rotatable circular frame 30 that can slide with respect to the inner surface of the said circular frame 20. On the side surfaces of the rotatable frames 30 that face each other, there are disposed at 12 equal intervals fixing pins 31, and each fixing pin 31 meshes so that it can slide in the long hole 22a that is provided in the center of the swing arms 22 mentioned above. Thus, when the rotatable frames 30 are rotated around the circular frames 20, each fixing pin 31 is moved in the long hole 22a of the swing erms 22, end each swing arm 22 rotates around its fastening pin 21. The rotatable frames 30, when they rotate around the circular frames 20, cause the swing arms 22 to rotate around the fastening pins 21 together, end the free bearing 24 of the ends of these swing arms 22 move in the direction of the diameter of the circular frames 20. Each swing arm 22 is of the same size as the other swing arms, and because the amount of rotation of each awing arm 22 caused by the rotation of the rotatable frame 30 is the same for each, the free bearing 24 of the end of each swing arm 22 is always positioned on a virtual circle that is concentric with the circular frame 20. Therefore, if the rotatable frame 30 rotates around the circular frame 20, the free bearing of the end of each swing arm 22 is positioned on a virtual circle the diameter of which is different from that of the virtual circle made before rotation.

A strip is introduced by a guide plate 70 into the virtual cylinder formed by the pipe-forming rollers 50, as shown in Figure 1. The guide plate 70 is perpendicular to the virtual cylinder formed by the pipe-forming rollers 50, and its bottom end is attached to the roller shaft 51 for one pipe-forming roller 50. This roller shaft is one of a pair of roller shafts 51 that extend in the horizontal direction. The strip that is introduced into the virtual cylinder formed by the pipe-forming rollers 50 is brought into contact with the pipe-forming rollers 50 end curved into a helix, resulting in e helical pipe.

In the virtual cylinder formed by the pipe- forming rollers 50, there is provided en introducing roller 80 that faces the pipe-forming roller 50 that is attached to this guide plate 70. The strip that is conveyed by the guide plate 70 is caught between the said introducing roller 60 and the pipe-forming roller 50 that faces the said introducing roller 80 end introduced into the virtual cylinder by the said introducing roller 80. The diameter of the virtual cylinder that is formed by the pipe-forming rollers 50 can be changed by the rotation of the rotatable frame 30 around the circular frame 20. The circuler frame 20 Is rotatably disposed on the square frame 11, end there is a helix angle adjustment means 40 that adjusts the helix angle of the pipe-forming rollers 50 with respect to the virtual cylinder formed by the pipe-forming rollers 50 in the space between the circular frame 20 and the square frame 11, so that the amount of rotation of the said circular frame 20 with respect to the square frame 11 can be changed. The helix angle adjustment means 40 is installed between the circular frames 20 and the square frames 11. The said helix angle adjustment means 40 has, as shown in Figure 4, e nut 41 that is rotatably disposed on the square frame 11 and a bolt 42 that is screwed into the nut 41. By a connecting part 43, one end of the bolt 42 and the circular frame 20 are rotatably connected with each other. The said helix angle adjustment means 40 can be disposed in the space between only one of the circular frames 20 and the square frame 11. In this ease, the other circular frame 20 is fixed to the square frame 11.

With this helix angle adjustment means 40, when the bolt 42 is roteted, it moves in the direction of the axis thereof, end the position of the end of bolt 42 with respect to the nut 41 can be changed. As a result, the distance between the square frame 11 to which the nut 41 is attached and the circular frame 20 to which the end of bolt 52 is attached can be changed. At this time, the nut 41 into which the bolt 42 is screwed is rotatable with respect to the square frame 11, and while the nut 41 is rotated with respect to square frame 41, the bolt 42 is screwed further into the nut 41 so that the circular frame 11 rotates around the square frame 11. When the circular frame 20 rotates around the square frame 11, the ends of the pipe-forming rollers 50 that are supported on the circular frame 20 by means of the awing arms 22 are rotated. As a result, the angles of the pipe-forming rollers 50 to the axis of the virtual cylinder formed by ell of the pipe-forming rollers 50 are changed all at the same time.

in the space between the circular frame 20 and the rotatable frame 30, there is e means 60 to adjust the amount of rotation of the rotatable frame 30 with respect to the circular frame 20. As shown in Figure 5, the means 60 for the adjustment of the amount of rotation has a bolt 62 that is disposed in the space between the circular frame 20 and the rotatable frame 30. The bolt 62 is attached rotatably to the circular frame 20 by a connector 61 at one end thereof, and it is attached rotatably to the rotatable frame 30 by a connector 64 at the other end thereof. The connector 61 that connects one end of the bolt 62 to the circular frame 20 is fixed to the one end of the bolt 62 by a nut 63 screwed onto the bolt 62, The nut 63 is prevented from rotating with respect to the bolt 62 by means of a pin 66. A connector 64 that connects the rotatable frame 30 with the other end of the bolt 62 is screwed onto the bolt 62. Further toward the end of the said bolt 62 than the position of the bolt 62 up to which the said connector 64 is screwed, there is screwed a nut 65. If the nut 65 is roteted end screwed forward with respect to the bolt 62, the said nut 65 collides with the connector 64, end accordingly, the connector 64 is fixed into position with respect to the bolt 62. If the nut 63 that is fixed to the bolt 82 is rotated when the nut 65 is separated from the connector 64, the bolt 62 rotates as one with the out 63, and the position at which the connector 64 is screwed to the bolt 62 is changed. In this way, the distance between the connector 61 that is attached to the circular frame 20 and the connector 64 that is attached to the rotatable frame 30 is changed, and the rotatable frame 30 is rotated with respect to the circular frame 20. By the rotation of the rotatable frame 30, the position of the free bearings 24 that are provided at the free ends of the swing arms 22 is changed. Thus, the diameter of the virtual circle around which the free bearings 24 are placed is changed.

There is a fixing means (not shown} for fastening together the circular and rotatable frames 20 end 30 in the position in the square frame 11 that is at the opposite angle to the means 60 to adjust the emount of rotation of the rotatable frame 30.

The operation of the pipe-forming machine of this invention is as follows:

First, the means 60 to adjust the amount of rotation of the rotatable frame 30, which is installed between the circular frames 20 and the rotatable frame 30, is operated in accordance with the diameter of a helical pipe to be made. At that time, the fixing means for fastening together the circular and rotatable frames 20 and 30 is removed from fastening them. For the operation of the adjustment means 60, first, the nut 65 is loosened to make it possible for connector 64 to move in the direction of its axis with respect to the bolt 62. In these circumstances, the nut 63 is turned and the position of the connector 64 with respect to the bolt 62 is adjusted. By this adjustment, the rotatable frame 30 is rotated with respect to the circuler frame 20. By the rotation of the rotatable frame 30, ell of the awing arms 22 move as one end the diameter of the virtual circle around which the free bearings 24 are arranged is changed. The free bearings 24 are plaoed on a virtual cirole that is conoentric with the circular frame 20. Then, the rotatable frame 30 is rotated until the diameter of this circle reaches a fixed diameter, end when this diameter has been reached, the nut 65 of the adjustment means 60 is brought up to a position in which it touches the connector 64. In this way, the rotatable frame 30 can be circular to the circular frame 20. As a result, the pipe-forming rollers 50 are positioned in the outer aide of a virtual cylinder with the desirad diameter. The same operation is repeated with the other circular end rotatable frames 20 and 30. After the above-mentioned adjustment, the circular frames 20 end the rotatable frame 30 are fixed to each other by the fixing means.

Next, so that the pipe-forming rollers 50 are set at a fixed helix angle to the axis of the virtual cylinder formed thereby, one of the circular frames 20 is rotated together with the rotatable frame 30 with respect to the square frame 11. This movement is brought about by the rotation of the bolt 42 of the helix angle adjustment means 40. By the rotation of the said bolt 42, the bolt 42 is screwed forward towards the connector 41 attached to the square frame 11, resulting in changes in the distance between the end of the bolt 42 and the square frame 11. As a result, the circular frame 20 to which the end of the bolt 42 is attached by the connector 43 is rotated, and accordingly the rotatable frame 30 that is connected into one piece with the circular frame 20 rotates with respect to the square frame 11. Together with this rotation, the free bearings 24 of the free ends of the swing arms 22 move along the surfece of the virtual cylinder formed by ell of the pipe-forming rollers 50. By the same operation on the other circular frame 20, rotation in the opposite direction can be achieved. As a result, the pipe-forming rollers 50 are brought to have a fixed helix angle with respect to the axis of the virtual cylinder formed by ell of the pipe-forming rollers 50.

In these circumstances, a strip is conveyed along the introduction guide 70, and the strip is introduced into the virtual cylinder formed by all of the pipe-forming rollers 50. The strip that has been introduced into the inside of this virtual cylinder comes into contact with the pipe-forming rollers 50 in turn, and the strip is forced to be curved by the pipe-forming rollers 50. The strip is conveyed always in the direction at right angles to the center of the axis of the pipe-forming rollers 50, so the strip is rolled into a helical shape by the pipe-forming rollers 50. The strip is rolled gradually into a helical shape, end the edges of the strip that have come together when the strip is rolled ere fitted together, resulting in a helical pipe with e fixed diameter, which is then conveyed to the outside of the said pipe-forming machine.

It is understood that various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope end spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be construed as encompassing all the features of patentable novelty that reside in the present invention, including all features that would be treated as equivalents thereof by those skilled in the art to which this invention pertains.

Claims

1, A tube-forming machine into which a strip is fed end then curved around into a helical fashion to form a helical tube, said machine comprising:

a fixed circular frame,

e plurality of awing arms positioned in such a manner that one end of each of said swing arms is pivoted on said fixed frame and the other end thereof ie disposed as s free end inside of the fixed frame, each of said swing arms having a pin or long hole in the middle portion thereof in the longitudinal direction of said swing arm,

e plurality of pipe-forming rollers that are rotatably supported by said free ends of said awing arms in such a manner that said rollers are positioned in a helical fashion on the outer side of e virtual cylinder having the same diameter as said helical tube, and

a rotatable circular frame that is rotatably positioned inside of said fixed frame, said rotatable frame having long holes or pins that slidably engage said pins or long holes of said swing arms whereby said swing arms are simultaneously swung around the pivotal ends thereof by the rotation of said rotatable frame,

wherein said strip is forced into said virtual cylinder formed by said rollers so as to allow said strip to be curved around into a helical convolution, resulting in a helical tube.

2. A tube-forming machine according to claim 1, wherein an adjusting means for adjusting the amount of rotation of said rotatable frame is disposed between the fixed frame and the rotatable frame.

3. A tube-forming machine according to claim 1, wherein said circular frame is supported by a square frame so as to be concentric with respect to said square frame,

4. A tube-forming machine according to claim 3, wherein a helix angle adjustment means is disposed in the space between the circular frame and the square frame, said helix angle adjustment means rotating said circular frame with respect to said square frame so as to move the ends of ell of the pipe-forming rollers at the same time, so that the angles of the pipe-forming rollers to the axis of the virtual cylinder formed by all of the pipe-forming rollers are changed, whereby the pipe-forming rollers are brought to have a fixed helix angle with respect to the axis of the said virtual cylinder.