AU784381B2

AU784381B2 - Device for continuous manufacture of an endless hollow cylinder and tubular articles of other convex cross sections

Info

Publication number: AU784381B2
Application number: AU54140/01A
Authority: AU
Inventors: Arkadiy Golovanevskiy; Vladimir Golovanevskiy
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-06-29
Filing date: 2001-06-29
Publication date: 2006-03-23
Anticipated expiration: 2021-06-29
Also published as: WO2003002323A1; AU5414001A; WO2003002323B1

Description

-41W 1 DEVICE FOR CONTINUOUS MANUFACTURE OF AN ENDLESS HOLLOW CYLINDER AND TUBULAR ARTICLES OF OTHER CONVEX CROSS SECTIONS This invention relates to improvements in devices for manufacture of tubular articles from reinforced polymers and other materials.

There are devices for continuous manufacture of endless tubular articles from reinforced polymers and other materials (eg. fibreglass pipes). They all employ different means of pulling the pipe off the mandrel while the pipe is being manufactured. For example, one previous device [USSR patent No.

234650] proposes mounted into a rotating single-piece mandrel push rods fitted with self-gripping eccentrics on their ends. This proposal has the disadvantage that the pipe being manufactured must meet certain minimum axial and radial strength requirements to ensure its integrity while in the process of pulling it off the mandrel since the self-gripping eccentrics push 15 against the inner surface of the pipe while moving forward in order to push the pipe off the mandrel. This imposes restrictions on the minimum permissible pipe wall thickness and the structure of the pipe wall. Furthermore, the device being described has inherent limitations of the production speed of the manufacturing process as an increase in the length of the mandrel causes a corresponding increase in the forces needed to be applied by the self-gripping eccentrics in order to pull the pipe off the mandrel. This results in the fact that, when some critical maximum mandrel length is reached it is impossible to ensure the integrity of the pipe being pulled by eccentrics off the mandrel.

Another previous device [USSR patent No.106359] proposes a mandrel composed of individual longitudinal elements (sectors) concurrently reciprocally moving along the longitudinal axis thereof in such a way that each of the sectors makes a cycle of movement comprising of a slow working stroke forward and an alternate quick return to the point of departure. This proposal has the disadvantage that, since the production speed of such processes is proportional to the length of the mandrel used the technical difficulties of manufacturing long mandrels with a large number of sectors result in a dramatic rise in the price of the mandrel. On the other hand, decreasing the number of sectors leads to an increase in the surface area of each of the sectors. This results in irregular feed and hence a decrease in quality of the pipe as a quickly moving back sector jerks the pipe backwards causing distortion of non-hardened (under-cured) areas of the pipe being manufactured.

These problems are overcome by the present invention, which provides a device (mandrel) for continuous manufacture of an endless hollow cylinder and tubular articles of other convex cross sections comprising a pipe-forming body manufactured with a possibility of concurrent reciprocating movement of its individual longitudinal components and an additional bearing element not being any part of the pipe-forming body, each of the individual longitudinal components of the pipe-forming body and the additional bearing element making a cycle of concurrent reciprocating movement consisting of a slow working stroke forward and an alternate quick return to the point of departure.

In one form of the invention, the device (mandrel) consists of several (eg. two) longitudinal components (sectors) connected with the groove of a cylindrical cam of the driving gear via tie rods with rollers and an additional bearing element. The additional bearing element comprises a slit bush with the inner conical surface spring-loaded to a cone at the end of a push rod. The other end of the push rod is connected with the groove of the cylindrical cam of the driving gear via a tie rod with a roller.

To assist with understanding the invention, reference will now be made to the accompanying drawings which show one example of the invention.

In the drawings: FIG. 1 shows the proposed device (mandrel) with two sectors connected to a driving gear, and an additional bearing element.

FIG. 2 shows the pipe-forming part of the mandrel with tie rods and the additional bearing element.

15 Referring to FIG. 1 it can be seen that the device for continuous manufacture of an endless hollow cylinder and tubular articles of other convex cross sections comprises a pipe-forming body 9 with an additional bearing element 19. The .devise is connected to driving gear comprising a console driving shaft 1 which is secured in supports 2 and has a gear wheel 3 on one end. On the other end of the driving shaft there are a cylindrical cam 4 and a crown bush 5 in the S. slots of which the tie rods of the sectors 7 and a push rod 8 are moving.

Sectors 7 represent the two halves of a cut-along-the-axis cylinder with a full length groove on their inside surfaces and tie rods 6 attached to one of their ends. The shank 10 of the driving shaft 1 comes into the internal cavity 11 formed by the two grooves of the sectors 7. Components 12 are press-fitted into the groove of one of the sectors 7. The groove of the other sector is slightly wider than that of the first one so that the sector moves over the side surfaces of the components 12 with guaranteed clearance. A push rod 8 moves freely inside the apertures of the components 12. The tail end of the push rod comes out through the slot in the shank 10 of the driving shaft 1 and connects with its tie rod. On the other end of the push rod there is a cone 13 to which a slit bush 15 with inner conical surface is spring-loaded with a spring 14.

FIG. 2 shows a close-up of the pipe-forming body with its tie rods with rollers and the additional bearing element with its push rod, tie rod, and the roller.

The rollers 16 of the tie rods 6 of the sectors 7 are situated in the feeding side 15 of the groove of the cylindrical cam 4, and the roller 17 of the tie rod 18 of the ol -oo push rod 8 is in the return side of the groove. The outer surface of the slit bush is in slight contact with the inner surface of the pipe being manufactured.

Rotation from a drive is transferred to the gear wheel 3, driving shaft 1, and to the block of spools with a protective tape 9. The block of sectors 11 is driven by the shank 1 of the driving shaft The rollers 16 of the tie rods 6 of the sectors 7 move in the feeding side of the groove of the cylindrical cam 4 and the sectors 7 move forward. At this time, the pipe being manufactured is being carried forward by the two sectors. At the same time, the roller 17 of the push rod 8 is moving in the return side of the groove of the cylindrical cam 4 causing the cone 13 and hence the slit bush to move in the direction opposite to the travel of the sectors 7. As a consequence of this, the load applied by the cone 13 to the inner conical surface of the slit bush 15 is being reduced, and so the outer diameter of the bush 15 is decreasing and the bush 15 is not contacting the inner surface of the cured part of the pipe that is being moved forward by the sectors 7.

When the roller 16 of one of the sectors 7 comes into the return side of the groove of the cylindrical cam 4 it causes its corresponding sector to start quickly moving back to its point of departure. At this time the roller 17 of the tie rod 18 of the push rod 8 is already moving in the feeding side of the groove of the cam, causing the push rod to move forward in the direction of the slit bush 15. The cone 13 applies a load to the inner conical surface of the slit bush 15 causing a quick increase in its outer diameter and therefore the bush comes in firm contact with the inner surface of the pipe being manufactured.

The pipe is now being carried forward by one of the sectors 7 on its working 15 stroke forward and by the push rod 8 with the slit bush 15. Any attempt of the pipe to move back with the moving back sector causes further increase in the pressure applied by the outer surface of the slit bush 15 to the inner surface of the pipe supporting the pipe and enhancing its movement forward.

eeoee It will be realised that the device for continuous manufacture of an endless 20 hollow cylinder and tubular articles of other convex cross sections according to this invention is not restricted to the form of pipe-forming body with additional bearing element shown in the example, but may use any other suitable arrangement which does not require an additional bearing element to be a part of the pipe-forming body of the device.

Claims

1. A device for continuous manufacture of an endless hollow cylinder and tubular articles of other convex cross sections comprising a pipe-forming body manufactured with a possibility of concurrent reciprocating movement of its individual longitudinal components and an additional bearing element not being any part of the pipe-forming body, each of the individual longitudinal components of the pipe-forming body and the additional bearing element making a cycle of concurrent reciprocating movement consisting of a slow working stroke forward and an alternate quick return to the point of departure.

2. The additional bearing element of claim 1 comprising a slit bush with the inner conical surface spring-loaded onto an inner cone, the outside surface of the split bush providing the additional bearing area to the inner surface of the tubular article being manufactured. Vladimir Golovanevskiy 29 June 2001 Arkadiy Golovanevskiy 29 June 2001