GB2194614A - Pipe scraper - Google Patents

Abstract

A scraper for a pipe 9 comprises a body, a scraper blade 3 and a drive roller 2 in parallel spaced relationship, a freely rotatable support roller 8 mounted on the body 1 and having an upper periphery parallel to the scraper blade 3 and drive roller 2, the scraper blade/drive roller and the support roller being capable of relative adjustment towards and away from each other. A guide/stop may be fitted to the body 1 and be adjustable along the length of the scraper blade 3. An alternative embodiment is shown in Fig. 4. <IMAGE>

Description

SPECIFICATION Pipe scrapers This invention relates to pipe scrapers.

There are several instances where the outer peripheral surface end of a length of pipe needs to be substantially free of any protruding irregularity and substantially free from any dirt or grease. This is particularly so with plastics pipes, adjacent ends of which are to be connected by a socket of plastics material and where the socket and the pipe ends are to be connected by fusion welding.

Attempts have been made hitherto to clean the peripheral end of plastics pipe by providing an apparatus into which the pipe end is inserted and with the apparatus equipped with means such as milling cutters to remove a small proportion of the outer surface of the pipe. However, the geometric shape of plastics pipes cannot be guaranteed, either as manufactured or as a consequence of a long length of pipe being coiled for storage and transportation. Any ovality or irregularity of the shape impairs considerably the efficiency of such apparatus. Obviously pipe peripheral ends can be cleaned by hand but this is an extremely labourious and time consuming operation that relies entirely on the operative for its effectiveness.

It is the object of the present invention to provide pipe scraping means of simple and cost effective character and which avoids those disadvantages mentioned above.

According to the present invention, pipe scraping means comprises a body, a scraper blade and a drive roller mounted on the body in parallel spaced relationship, a freely rotatable roller mounted on the body extending in the same direction as, and having an upper periphery parallel to, the scraper blade and drive roller, the scraper blade/drive roller and the support roller being capable of relative adjustment towards and away from each other, and the top dead centre of the support roller lying in a plane positioned between the plane of the scraper and the plane of the longitudinal axis of the driven roller. A guide/stop may be fitted to the body and be adjustable along the length of the scraper.

According to one aspect of the present invention pipe scraping means comprises a body a. fixed scraper blade and a drive roller mounted on the body in parallel spaced relation, a support block mounted on the body such as to be adjustable towards and away from the body and a freely rotatable roller secured to the support block and extending in the same direction as and being parallel to the scraper blade and the drive roller, the top dead centre of the support roller lying in a plane positioned between the plane of the scraper blade and the plane of the longitudinal axis of the driven roller.

Thus, with the adjustable guide/stop set at the required position and the support block and its support roller positioned at a distance from the housing, the means of the invention can be placed over a pipe end with the support roller lying within the pipe and with the scraper blade and the drive roller lying externally of the pipe peripheral end, and the guide/stop abutting the pipe end. The support block can then be brought towards the housing until such time as the support roller contacts the internal wall of the pipe end and the scraper blade and the drive roller contact the outer wall of the pipe end to trap the pipe end between them. The driven roller can then be caused to rotate to drive the means of the invention around the pipe end enabling the scraper blade to scrape the end of the pipe to a degree sufficient to produce a clean regular surface.The length of the pipe peripheral surface being scraped is controlled by the position of the adjustable guide/stop. The longitudinal alignment of the scraper blade on the pipe is maintained by the three point contact between the drive roller, the scraper blade and the support roller.

According to a second aspect of the invention, pipe scraping means comprises a body, a scraper blade and a drive roller adjustably mounted on the body in parallel spaced relationship, a freely rotatable roller mounted on the body and extending in the same direction as, and having an upper periphery parallel to, the scraper blade and drive roller, and the top dead centre of the support roller lying in e plane positioned between the plane of the scraper and the plane of the longitudinal axis of the drive roller. Again, a guide/stop may be provided mounted on the body and adjustable along the length of the scraper.

Preferably, the body is a one-piece body of generally U-shaped configuration providing considerable stability and resistance to bending moments. It is further preferred to mount the freely rotatable roller directly on one (inner) leg of the U-shaped body, and is still further preferred to employ a conically-shaped roller, with the spindle set at an angle to bring the top of the roller parallel to the drive roller and the scaper blade.

The drive roller and the scraper blade may be provided on a support block with the support block adjustably mounted on the other (outer) leg of the U-shaped body. Thus, the end of a pipe can be introduced between the legs of the U-shaped body to locate against the guide/stop and locate the freely rotatable roller within the pipe, and the drive roller and scraper blade externally of the pipe peripheral end. Adjustment of the support block can then be effected to bring the drive roller and scraper blade into contact with the exterior of the pipe and trap the pipe between the drive roller and scraper, and the freely rotatable roller, with a required pressure provided between the scraper and the pipe.The driven roller can then be caused to rotate to drive the means of the invention around the pipe end enabling the scraper blade to scrape the peripheral end of the pipe to a degree sufficient to produce a clean regular surface.

It will be immediately apparent that the means of the invention can accommodate any ovality or any other irregularity in the shape of the pipe end thereby enabling efficient cleaning of the pipe peripheral end in exceedingly simple manner. It is a further advantage of the invention, that with any one particular scraper, drive roller of particular diameter and support roller of particular diameter, the pipe scraper of the invention can accommodate a range of pipe diameters.

Preferably the drive roller has a serrated external surface to increase its frictional effect on the peripheral end of the pipe, it being further preferred that the spindle extends either through the housing or through the support block to be engaged by a suitable drive handle for manual operation. It is still further preferred that the scraper blade whilst being fixed in relation to the housing or the support block is mounted in such a manner as to enable its position to be adjusted dependent upon the degree of scraping that is required. To improve still further the cleaning efficiency, it is desirable that the edge of the scraper blade in contact with the pipe has a serrated configuration.

The means of adjustment of the support roller or the support block for the scraper and drive roller on the housing can be provided in simple mechanical manner. Thus, for adjustment of the support roller two dependent slide bars may be provided on the housing to pass through corresponding guide holes in the support block with an adjusting screw extending from a drive handle externally of the housing through the housing and through a threaded hole in the- support block.When it is the support block with the drive roller and scraper blade that is adjustable, it is preferred that the support block has a central threaded stem passing through an adjusting nut mounted on one (upper) leg of the U-shaped body. -# As a means of allowing ready adaptation of the pipe scraper for use with pipes of different diameter, an indexable scraper blade can be provided, with, for example, four scraping edges each having a particular rake angle to suit a particular range of pipe diameters. Alternatively and as a means of providing longer life, an indexable scraper with, e.g. four scraping edges of the same, universally-usable rake angle, could be provided.

Two embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side elevation of one embodiment of pipe scraping means in accordance with the invention; Figure 2 is a section on the line Il-Il of Figure 1; Figure 3 is a side elevation of a second embodiment in accordance with the invention; Figure 4 is a part sectional side elevation of the second embodiment of the invention; and Figure 5 is a section on the line V-V of Figure 3.

In Figures 1 and 2, peripheral pipe end scraping means has a body 1 on which are mounted in spaced parallel relationship a drive roller 2 and a scraper blade 3. Depending from the body 1 are two slide bars 4, with an adjusting screw 5 lying centrally of the slide bars, and extending through the body to aid adjusting screw head 6. Mounted on the slide bars is a support block 7 for a support roller 8 the adjusting screw passing through a threaded hole in the support block.

Thus, with the support block 7 and roller 8 in a lowered position, the support roller 8 can be passed into a plastics pipe 9, and the screwhead 6 activated to raise the support roller and hence the pipe 9 into contact with the drive roller 2 and scraper blade, and with the top dead centre of the support roller contacting the internal wall of the pipe in a plane between the lines of contact of the drive roller and scraper blade on the pipe exterior.

The shaft 10 of the drive roller extends to a square drive 11 and which can be engaged by a suitable drive handle not shown. Thus rotation of the drive roller in the clockwise direction as shown in Figure 2 draws the scraper blade around the peripheral pipe end to scrape the periphery to a degree determined by the degree of pressure of the blade on the pipe end determined by the degree of pressure imposed through the screw 5.

In the second embodiment of the invention as shown in Figures 3 to 5, scraping means comprises a relatively U-shaped body 12 with a conical support roller 13 rotatably mounted at the end of one (lower) leg 14 of the body.

Mounted on the other (upper) leg 15 is a support block 16 having a generally central mounting screw 17 extending through a plane hole 18 in that leg and through an adjusting nut 19 lying in a slot 20 in the end of the leg.

The screw has diametrically opposed flats 21 to engage the flats in a hole in the end of a pressure plate 22.

Mounted on the support 16 is a rotatable drive roller 23, the spindle of which extends to a square drive 24, and a square section scraper blade 25 that is indexable to provide four cutting edges, each of the same rake to provide extended life, or each of a different rake angle to accommodate different pipes.

Thus, with the support raised, the support roller 13 can be positioned inside a pipe end, and the support then lowered to bring the drive roller and scraper blade into contact with the peripheral pipe end, and the support roller into contact with the inner periphery of the pipe in a plane lying between the planes of contact of the drive roller and the scraper.

With a suitable drive handle secured to the square drive 24, the scraper blade can be drawn around the pipe to scrape the peripheral pipe end. The degree of scraping is, in this embodiment controlled by the pressure plate 22. Thus the support block 16 is lowered until the drive roller, scraper, and support roller are in contact with the pipe, and the pressure plate swings through approximately 270 degrees to effect a final tightening of the assembly on to the pipe end.

For better scraping action, it is preferred in both embodiments that the scraper blade has a serrated scraping edge (or edges). As is indicated in Figure 3, an adjustable stop 26 is provided to limit the degree of penetration of the pipe end into the scraper.

Claims (17)

1. Pipe scraping means comprising a body, a scraper blade and a drive roller mounted on the body in parallel spaced relationship, a freely rotatable roller mounted on the body extending in the same direction as, and having an upper periphery parallel to, the scraper blade and drive roller, the scraper blade/drive roller and the support roller being capable of relative adjustment towards and away from each other, and the top dead centre of the support roller lying in a plane positioned between the plane of the scraper and the plane of the longitudinal axis of the driven roller.

2. A scraping means as in Claim 1 and comprising a body, a fixed scraper blade and a drive roller mounted on the body in parallel spaced relation, a support block mounted on the body such as to be adjustable towards and away from the body and a freely rotatable roller secured to the support block and extending in the same direction as and being parallel to the scraper blade and the drive roller, the top dead centre of the support roller lying in a plane positioned between the plane of the scraper blade and the plane of the longitudinal axis of the driven roller.

3. A scraping means as in Claim 1 or Claim 2, wherein an adjustable stop is provided to determine the degree of penetration of the pipe end into the scraping means.

4. A scraping means as in Claim 2 or Claim 3, wherein the means of adjustment of the support roller or the support block for the scraper and drive roller on the housing comprises two dependent slide bars provided on the housing to pass through corresponding guide holes in the support block with an adjusting screw extending from a drive handle externally of the housing through the housing and through a threaded hole in the support block.

5. A scraping means as in Claim 1 and comprising a body, a scraper blade and a drive roller adjustably mounted on the body in parallel spaced relationship a freely rotatable roller mounted on the body and extending in the same direction as, and having an upper periphery parallel to, the scraper blade and drive roller, and the top dead centre of the support roller lying in a plane positioned between the plane of the scraper and the plane of the longitudinal axis of the drive roller.

6. A scraping means as in Claim 5, wherein an adjustable stop is provided to determine the degree of penetration of the pipe end into the scraping means.

7. A scraping means as in Claim 5 or Claim 6, wherein the body is a one-piece body of generally U-shaped configuration.

8. A scraping means as in any of Claims 5 to 7, wherein the freely rotatable roller is mounted directly on one (inner) leg of the Ushaped body.

9. A scraping means as in Claim 8, wherein a conically-shaped roller is employed with the spindle set at an angle to bring the top of the roller parallel to the drive roller and the scraper blade.

10. A scraping means as in any of Claims 5 to 9, wherein the drive roller and the scraper blade are provided on a support block with the support block adjustably mounted on the other (outer) leg of the U-shaped body.

11. A scraping means as in Claim 10, wherein the support block has a generally central threaded stem passing through an adjusting nut mounted on the body.

12. A scraping means as in Claim 11, wherein the threaded stem has diametral flats to be engaged by the sides of a hole in the end of a pressure plate, and whereby the stem can be turned by the plate to effect a final tightening of the assembly on a pipe end.

13. A scraping means as in any of Claims 1 to 12, wherein the drive roller has a serrated external surface to increase its frictional effect on the peripheral end of the pipe, and the spindle operation.

14. A scraping means as in any of Claims 1 to 13, wherein the scraper blade has more than one scraping edge, and is indexably mounted.

15. A scraping means as in any of Claims 1 to 14, wherein the or each scraping edge of the scraper blade is serrated.

16. A scraping means substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

17. A scraping means substantially as hereinbefore described with reference to Figures 3 to 5 of the accompanying drawings.