AU693173B2

AU693173B2 - Manufacture of concrete pipes

Info

Publication number: AU693173B2
Application number: AU20021/95A
Authority: AU
Inventors: Graham Gill; Gary Raymond Griffith
Original assignee: CSR Humes Pty Ltd
Current assignee: CSR Humes Pty Ltd
Priority date: 1994-06-03
Filing date: 1995-05-11
Publication date: 1998-06-25
Anticipated expiration: 2015-05-11
Also published as: AU2002195A

Description

I

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT 444*44 4 444~ 6644 4 4*4 4 44 4 4 4 4.

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4 4 Applicant: CSR HOMES PTY. LIMITED A.C.N. 003 644 111 Invention Title: MANUFACTURE OF CONCRETE PIPES The following statement is a full description of this invention, including the best method of performing it known to us: I aaS o a a a i 2 MANUFACTURE OF CONCRETE PIPES This invention relates to the manufacture of concrete pipes, and more particularly a pipe mould within which to manufacture concrete pipes, and more particularly, the invention relates to concrete pipes in which are embedded steel lifting lugs adapted for engagement by lifting tools, devices or cranes, including mobile cranes.

The invention the subject of this application relates to a mould for forming a concrete pipe with lifting lugs embedded in the wall thereof, with one portion of each lug extending radially outwardly beyond the circumferential surface of the pipe and having means for engagement by lifting means, and with the remainder of the lug extending radially inwardly of the pipe wall to be embedded therein.

One of the problems associated with the manufacture of such pipes is the correct location of the lifting lugs in the mould preparatory to casting the pipe, particularly with regard to the length of the portion of the lugs which is to be embedded in the wall of the pipe 20 relative to the thickness of the wall of the pipe.

It is therefore an object of the present invention to provide a mould for a concrete pipe which allows for a relatively accurate positioning of the lifting lugs whilst the pipe is being moulded.

25 The invention is applicable to moulds which are formed from mould segments adapted to be joined along their edges to define a cylindrical mould cavity in which the pipe will be cast, such as by spin moulding, or a cylindrical mould in one piece and having a seam or joint extending longitudinally therealong whereby after a pipe is moulded, and the concrete is cured, the facing edges on either side of the seam can be drawn sufficiently away from each other whereby to release the mould from the pipe surface whereafter the moulded pipe can be axially removed from the mould.

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l~ is envisaged a mould for a concrete pipe to have at least one lifting lug embedded therein, said mould having at least one longitudinally extending seam and defines a cylindrical'8avity in which a pipe is to be moulded, wherein said seam or one of said seams is formed from longitudinally extending abutting edge faceG carried by the mould at said seam and adapted to be joined together, one of said edge faces having at least one cavity therein the outer end of which is adapted to receive the head of a lifting lug of magnetic responsive material, wherein a member of magnetic material is received within said cavity and against which, in use, the head of the lug is held due to magnetic attraction, with the radial position of said cavity setting the position of the lug within the mould to determine the amount of the length of the lug which will be embedded in the wall of the pipe when moulded or cast.

Preferably means are provided to adjust the position of the member of magnetic material within the cavity to allow the cavity to accommodate lugs with 20 different sized heads.

One preferred embodiment of the invention will now be described with reference to the accompanying drawings, in which; Figure 1 is a cross-sectional view through 25 portion of a pipe wall in which a lifting lug is embedded, Figure 2 is a cross-sectional view through part of a seam of a pipe mould in accordance with the preferred embodiment of the invention and with the seam open, Figure 3 is a cross-sectional view similar to that of Figure 2, but with the seam closed, and Figure 4 is a side elevational view of the seam configurations of Figures 2 and 3.

Referring to Figure 1 of the drawings, the concrete pipe to which the pipe mould of the present invention relates, and which figure shows portion only of the wall of a pipe 1, has a steel lifting lug 2 embedded stafflenne/keep[PM6067 11.5 -4 therein during the formation of the pipe and having an external end portion 3 extending radially beyond the outer surface of the pipe with a lifting head 4 formed on the end thereof to bd engaged by a lifting tool, device or crane.

The remaining portion 7 of the length of the lug extends radially inwardly of the pipe wall to be embedded therein and carries on its inner embedded end an enlarged formation, such as an annular flange 6, which serves to resist radial disengagement of the lug from its embedded position within the pipe wall.

With reference to Figures 2, 3 and 4 of the drawings, there is shown part of a pipe mould formed from thin and therefore relatively flexible metallic material and defining a cylindrical mould cavity. The pipe mould has a longitudinally extending seam 10 whereby after a pipe is moulded and the concrete has cured the facing edges on either side of the seam can be drawn sufficiently away from 0,0,9:each other whereby to release the mould from the pipe 00 0 surface whereafter the moulded pipe can be axially removed o 20 from the mould.

00.0 In accordance with this preferred embodiment of the invention, the facing edges of the mould at the seam have flanges 11 and 12 carried thereby. one of the flanges 11 has a cavity 16 formed therein at the required position for the lifting lug 2, and usually two lifting lugs are provided at longitudinally spaced apart positions along the 0 pipe wall. A plug 14 of magnetic material is located in the cavity 16 at a position leaving a sufficient remaining length of cavity which will accommodate one side portion of the head 4 of the lug with the side of the length of the lug abutting the face 15 of the flange 11 radially inwardly of the mould. The other flange 12 has an opening therethrough aligned with the cavity 16 to receive the other side of the head 4 of the lug. A pair of locating bars 17 are provided on the faces of the flanges 11 and 12 radially outwardly of the mould, and which bars abut each staff/nne(1keep/PM6067 11.5 5 other when the seam is closed as shown in Figure 3.

As a result of the above, the head of the lug is firstly held in position by the magnetic plug when the seam is open and' ubsequently captured between the flanges 11 and 12 and the locating bars 17 when the seam is closed.

The position of all components relative to the head of the I lug sets the amount of the length of the lug which will I extend into the mould cavity and therefore the length of Ithe lug that will be embedded within the wall of the pipe and as a consequence the length thereof which will extend radially outwardly from the surface of the pipe, when the pipe is moulded.

The outer face of flange 11 adjacent the cavity 16 has a nut 18 attached thereto, such as by welding, and into which an adjusting bolt 21 is screwed in alignment with the cavity, and by screwing the bolt inwardly and outwardly of the cavity the position of the plug of magnetic material within the cavity can be adjusted to allow the size of the remainder of the cavity to be adjusted to accommodate different sized heads for the lug.

A lock nut 19 is also provided to lock the bolt at any required position.

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Claims

1. A mould for a concrete pipe to have at least one radially extending lifting lug embedded therein, said mould having at least one longitudinally extending seam and defines a cylindrical cavity in which a pipe is to be moulded, wherein said seam or one of said seams is formed from longitudinally extending abutting edge faces having at least one cavity therein the outer end of which is adapted to receive the head of a lifting lug of magnetic responsive material, wherein a member of magnetic material is received within said cavity and against which, in use, the head of the lug is held due to magnetic attraction, with the radial position of said cavity setting the position of the lug within the mould to determine the amount of the length of the lug which will be embedded in the wall of the pipe when moulded or cast.

2. A mould as claimed in Claim 1, wherein the edge faces are formed by flanges on the edges of said mould at said longitudinal seam.

3. A mould as claimed in Claim 1 or 2, wherein means are provided to adjust the position of the member of i magnetic material within the cavity to allow the cavity to 4' 4 accommodate lugs with different sized heads.

4. A mould as claimed in Claim 3, wherein the eet adjustment means is an adjusting bolt aligned with the inner end of the cavity and engaging the member of magnetic material to be movable inwardly and outwardly relative to the cavity to adjust the position of the member of magnetic material.

5. A mould as claimed in any one of the preceding claims, wherein the mould has two longitudinally spaced apart cavities with members of magnetic material therein staftlenne/keeplPM6067 11.5 -7- and each for receiving the head of a lug.

6. A mould for a concrete pipe, substantially as J hereinbefore'lescribed with reference to the accompanying |drawings.

7. A concrete pipe formed in a mould as claimed in any one of the preceding claims. 14 I j 4*11 4, 4 S* i i *.4 4 4 .4 4 6 «6 C 1 4 a sta~ennalkeopPM6067 11.5 9 V tfh4~ 4414:1 I I- ABSTRACT A mould for a concrete pipe having at least one radially extending lifting lug embedded therein. The mould has at.least one longitudinally extending seam and defines a cylindrical cavity in which the pipe is to be moulded. The seam is formed from longitudinally extending flanges (11 and 12) in one of which at least one cavity (16) is formed, the outer end of which is adapted to receive the head of the lifting lug which is formed from magnetic responsive material, such as steel, whilst a plug (14) of magnetic material is received within the cavity and against which, in use, the head of the lug is held due to magnetic attraction. The radial position of the cavity sets the position of the lug within the mould and determines the amount of the length of the lug which will be embedded in the wall of the moulded pipe. stafflennelkeeplPM607 11.5 heI o 4. *r 0 II.. 44444 4 4r~