AU2008201637B2

AU2008201637B2 - Concrete pit component and method of manufacture of same

Info

Publication number: AU2008201637B2
Application number: AU2008201637A
Authority: AU
Inventors: Stephen Gowland
Original assignee: Aco Pty Ltd
Current assignee: Aco Pty Ltd
Priority date: 2007-04-13
Filing date: 2008-04-14
Publication date: 2015-06-18
Anticipated expiration: 2028-04-14
Also published as: AU2008201637A1

Abstract

A method of manufacturing a concrete component 10 of a pit comprises forming a mould 39 defining a casting cavity 43 5 and locating a catch 22 that comprises two separate catch portions 34 into the casting cavity 43 where the catch/catch components are configured to engage a member when the concrete component is in use. One or more cores 44 are located in the casting cavity 43 adjacent the catch 10 22/catch portions 34. The casting cavity 43 is then filled with concrete. When the concrete has sufficiently set to form the component, the component is separated from the mould and the cores 44 removed which form corresponding access passages 46 which enable the member 15 to be inserted into and removed from the catch 22. N:\Perth\Cases\Patent\63000-63999\P6361 1.AU.i\Specis\P636 1.AU. 1 Specification 2008-4-9.doc 14/04/08 0 ~jDO

Description

EDITORIAL NOTE APPLICATION NUMBER - 2008201637 It should be noted that there is no page 1.

- 2 CONCRETE PIT COMPONENT AND METHOD OF MANUFACTURE OF SAME Field of the Invention 5 The present invention relates to a concrete pit and components thereof, which provide access to underground utilities such as communication lines, gas and water pipes and the like. 10 Background of the Invention Pits are provided in the ground to allow access to subterranean utilities such as communication lines, 15 electricity cables, water and gas pipes, and control gear. A typical concrete pit comprises four walls forming a box like structure. An upper end of the box like structure is closed with a separate lockable cover or lid typically made from heavy gauge steel plate. A lower end of the box 20 like structure is either formed with an integral floor or is also left open and seated on either the ground or a support or base placed in a hole into which the pit box is placed. 25 In order to facilitate the locking of the cover onto the pit, catches or other mechanisms may be screwed or bolted onto an inside surface of the box like structure to receive a cross-bar. The cross-bar can then be locked to a cover plate using a padlock. 30 Summary of the Invention In the claims of this application and in the description of the invention, except where the context requires 35 otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises"! or "comprising" are used in an inclusive 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 3 sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 5 Throughout this specification the expressions "component of a pit" and "pit component" are intended to denote a structural part of a pit to which a cover can be locked. This may include a pit box having side walls with an open or closed bottom and an open top that is disposed in a 10 hole in the ground to form the pit; or a pit collar or plinth which is in the form of a concrete rim that is connectable to a pit box. According to one aspect of the present invention there is 15 provided a method of manufacturing a concrete component for a pit comprising: forming a mould defining a casting cavity for the component; locating a catch in the casting cavity, the catch 20 having a surface provided with an opening that is open at one end and closed at an opposite end, wherein locating the catch includes positioning the catch in the casting cavity so that the surface abuts against a portion of the mould to allow the surface of the catch to be flush with a 25 resulting inside surface of the concrete pit box, the catch also configured to engage a member when the component is in use; placing one or more cores in the casting cavity adjacent the catch, wherein at least one of the one or 30 more core blocks is placed adjacent the one end of the catch that is open to provide an access passage to enable the cross-bar to be inserted into and removed from the catch; filling the casting cavity with concrete; 35 when the concrete has sufficiently set to form the component, separating the component from the mould; and, removing the or each core. 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 3a The method may further comprise supporting the catch on or in the mould. This may involve attaching the catch to the mould with a mechanical fastener. 5 The method may further comprise providing the catch as two separate catch portions. In this embodiment the method comprises locating the catch portions at diametrically opposed locations in the casting cavity. In one embodiment the method may comprise placing a reinforcing 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 structure in the casting cavity prior to filling the casting cavity with concrete. In this embodiment the method may further comprise attaching the catch or catch portions to the reinforcing structure. The reinforcing 5 structure may typically comprise a metallic wire mesh such as a steel mesh. The method may further comprise forming the catch with a coupling and wherein the attaching of the catch to the 10 reinforcing structure comprises attaching the coupling to the reinforcing structure. Further, the attaching may comprise passing the or a portion of the reinforcing structure through the coupling. 15 The forming of the mould may comprise forming an inner mould, forming an outer mould, and juxtaposing and/or coupling the inner mould to the outer mould to form the casting cavity. In this embodiment, supporting the catch on or in the mould comprises supporting the catch on the 20 inner mould. According to a further aspect of the present invention, there is provided a concrete component of a pit, the component made in accordance with the above method. 25 More particularly, a further aspect of the present invention provides a concrete pit component comprising: a concrete structure defining an opening and having an outside surface that extends about an outside of the 30 opening and an inside surface that extends about an inside of the opening; and, a catch embedded in the concrete structure the catch having a surface that is flush with the inside surface and is provided with a slot that is open at one end and closed 35 at an opposite end; the concrete component further comprising an access passage formed in the inside surface adjacent the one end 6545187_1 (GHMatters) P63611.AU.1 ROSG - 4a of the opening to enable the cross-bar to be inserted into and removed from the catch. In another aspect, there is provided a method of 5 manufacturing a concrete pit box for a pit comprising: forming a mould defining a casting cavity for the concrete pit box; locating a catch in the casting cavity, the catch adapted to engage a cross-bar when the concrete pit box is 10 in use; placing one or more core blocks in the casting cavity adjacent the catch; filling the casting cavity with concrete; when the concrete has sufficiently set to form the 15 concrete pit box, separating the concrete pit box from the mould; and, removing the or each core In another aspect, there is provided a concrete pit box 20 component comprising: a concrete structure defining an opening and having an outside surface that extends about an outside of the opening and an inside surface that extends about an inside of the opening; and, 25 a catch embedded in the concrete structure the catch having a surface that is flush with the inside surface and is provided with an opening that is open at one end and closed at an opposite end, the catch also adapted to engage a cross-bar when the concrete pit box is in use. 30 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 5 Brief Description of the Drawings An embodiment of the present invention will now be described by way of example only with reference to the 5 accompanying drawings in which: Figure 1 is a schematic representation of a pit component manufactured in accordance with an embodiment of the present invention; Figure 2 is a view of section AA of the pit component 10 shown in Figure 1; Figure 3 is a representation of a part of a mould used in an embodiment of the present method; Figure 4 is a schematic representation of a mould used in forming an embodiment of the present method; 15 Figure 5 is a copy of a photographic representation of a further embodiment of a pit component in accordance with the present invention; and, Figure 6 is a schematic representation of a pit component in accordance with a further embodiment of the 20 present invention. Detailed Description of Preferred Embodiments The accompanying drawings depict an embodiment of a 25 concrete component 10 of a pit made in accordance with the present method. The component 10 in this instance is a pit box 12. The pit box 12 is a concrete structure having four side walls 14a, 14b, 14c and 14d (hereinafter referred to in general as "side walls 14") that are 30 integrally formed in the shape of a rectangular box having an opening 16 at an upper end. An opposite end of the pit box 12 may be formed with either an open end or an integrally formed floor or bottom wall (not shown) . The pit box 12 has an outside surface 18, which is outside of 35 the opening 16, and an inside surface 20 that is inside of the opening 16. The outside and inside surfaces 18, 20 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 6 are formed by the outside and inside surfaces respectively of the walls 14. The pit box 12 further comprises a catch 22. The catch 22 5 is embedded in the concrete from which the pit box 12 is made and has a surface 24 that is flush with the inside surface 20. The catch 22 is also provided with an opening which in this instance is in the form of a slot 26 that is open at one end 28 but closed at an opposite end 30. 10 In use, the catch 22 is able to engage a member such as a cross-bar 32 (shown in phantom) to enable locking of a cover or pit lid (not shown) to the pit box 12. 15 In the illustrated embodiment, the catch 22 is made from two separate catch portions 34a and 34b (hereinafter referred to in general as "portions 34") that are located at diametrically opposed locations within the pit box 12. Each of the portions 34 is in the form of a short length 20 of rectangular steel tube in which a respective slot 26 is cut. As shown in Figures 2 and 3, in order to assist in retaining the catch 22 and indeed the catch portions 34 within the concrete of the pit box 12, the catch portions 34 are each provided with a coupling in the form of a loop 25 36 that extends rearwardly from and is attached to a back face 38 of the catch portion 34. The loop 36 may typically be welded to its respective catch portion 34. In the manufacture of the component 10, a mould 39 is 30 formed to define a casting cavity. The mould 39 (see Figures 3 and 4) typically comprises an inner mould 40 and an outer mould 41 that are relatively juxtaposed and/or coupled together to define the casting cavity 43. Both the inner mould 40 and the outer mould 41 are in the 35 general form of four walls defining a rectangle, with the inner mould having sides of a shorter length than the outer mould so that a space is formed between the inner 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 and outer moulds to form the casting cavity 43 in which the component 10 is cast. The catch 22 and in particular catch portions 34 are 5 located in the casting cavity so as to engage the cross bar 32 when the pit component 10 is in use. Various templates, jigs or markings may be used to ensure that the catch 22 is correctly located. In this particular embodiment, a spacer block 42 is provided for each catch 10 portion 34 to sit on prior to filling the mould with concrete. The block 42 places the portion 34 at the correct elevation within the box 12. A mechanical fastener such as a tek screw may be used to also hold the portion 34 in place during the casting process. In this 15 regard a tek screw would be screwed into the face 24 of the portion 34 from a side of the inner mould 30 opposite the portion 34. A core block 44 is placed adjacent the portion 34 within 20 the casting cavity for forming an access passage 46 (see Figure 1) in the pit box 12. The access passage 46 is used to enable the cross-bar 32 to be inserted into and removed from the catch 22. An upper end of the core block 44 is formed with a sloping surface 48 which produces a 25 corresponding downwardly sloping surface 50 in the access passage 46. This assists in draining of water and debris that may enter the access passage 46. A reinforcing structure in the form of a steel mesh 52 is 30 placed in the casting cavity 43 to reinforce the concrete. The catch 22 can be attached to the steel mesh 52. This attachment may be by way of welding. However other attachments are possible such as by tying using wire. A strand of the steel mesh 52 can also be threaded through 35 the loop 36. 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 8 After the casting cavity has been filled with concrete and the concrete sufficiently set to provide the pit box with structural integrity, the pit box 12 is removed from the mould typically by separating it from each of the inner 5 and outer moulds. The block 42 and core block 44 are then removed. Following the full setting of the concrete, the component 10 is ready for use. Figures 1 to 4 illustrate concrete component 10 in 10 accordance with embodiments of the present invention, having a catch 22 and corresponding catch portions 34 for receiving a cross bar 32 of a pit lid. However, embodiments of the present invention may be extended to the formation of a pit component, such as a pit box 12, 15 illustrated in Figure 5 in which one or two additional second catches 60 are embedded in the pit box 12 for engaging a lip formed on the inside of a pit lid. The or each second catch 60 has a surface 62 that is flush with the inside surface 20 of the pit box 12. The surface 62 20 is provided with an opening in the form of an elongated slot 64 for receiving the lip. Typically, the catch 60 is in the form of a metallic U-shaped channel that is embedded in the pit box 12 using similar techniques and processes as described above in relation to the catch 20. 25 In this regard, the catch 60 may be provided with one or more loops similar to loop 36 for engaging or coupling with the steel mesh 52. The or each catch 60 is supported in the mould during the manufacturing process in the same manner as the catch 20 and catch portions 34. However, 30 the access passage 46 used in relation to the catch 22 is not required for the catch 60. Each catch 60 extends the full length of the inside of the pit box 12 and is provided in the side or sides not containing the catch 20. 35 In one embodiment, one catch 60 is used and installed in one side of the pit component not having a catch portion 34. In this embodiment, the pit lid is made of two 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 9 plates: one provided with the lip that is engaged in catch 60 and the other adapted to couple with the cross bar 32. The plate coupled with the cross bar 32 also overlies a second lip on the first plate. In this way, a 5 single cross bar 32 can lock both plates to the pit box 12. However, in another embodiment where a three-plate pit lid is required, two catches 60 are used, one embedded in each 10 of the two sides not containing the catch portion 34. Of the three plates, two end plates are provided with respective lips that engage a corresponding catch 60. The third of the plates, which is a middle plate, is coupled to the cross bar 32 and overlies a second lip on each of 15 the first two plates so that again a single cross bar can effectively lock each of three plates of a three-plate lid to the pit box 12. This embodiment is depicted schematically in Figure 6, 20 which shows a pit box 12 having two catches 60 embedded in the concrete used to make the box 12. The catches 60 are provided with loops 36 that are embedded in the concrete and may be engaged with steel mesh used as reinforcing in the box 12. A pit lid 70 is shown, being made of three 25 plates 72, 74, 76. Each of end plates 72 and 76 has a first lip 78 that engages a respective catch 60. Each end plate 72, 76 also has a second lip 80 that is overlaid by the centre plate 74. The centre plate 74 is coupled with the cross bar 32. The opposite ends of the cross bar are 30 engaged with the catch 22 and corresponding catch portions 34a, 34b as described hereinbefore and illustrated in Figure 2. Now that an embodiment of the invention has been described 35 in detail it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 10 concepts. For example, the catch 22 is illustrated and described as comprising two separate and individual catch portions 34a and 34b. However, in an alternative embodiment, the catch portions 34a 34b may be connected 5 together for example by a metal strap or rod so as to form a single unit. In such an embodiment, the strap or rod can be connected for example by welding to the back faces 38 of the portions 34 in place of the loops 36. This arrangement may assist in further embedding the catch 22 10 within the concrete of the component 10. In an additional or alternative variation, the portions 34 may also be provided with fingers, webs or other tie members that extend into the casting cavity to increase the strength of the connection the catch 22 to the concrete structure. In 15 a further variation, the catch 22 can be made of a different configuration. For example, each catch portion 34, rather than being in the form of a length of rectangular steel tube, can be in the form of a angle iron with one side parallel to the wall 14 and its other side 20 extending perpendicular to the wall 14 to form a lip or flange to engage the cross-bar. Further, the opening in each catch portion 34 is illustrated and described as a slot 26; however, other shapes and configurations of openings are possible. 25 All such modifications and variations together with others that would be obvious to a person of ordinary skill in the art are deemed to be within the scope of the present invention the nature of which is to be determined from the 30 above description and the appended claims. 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15

Claims

1. A method of manufacturing a concrete pit box for a pit comprising: 5 forming a mould defining a casting cavity for the concrete pit box; locating a catch in the casting cavity, the catch having a surface provided with an opening that is open at one end and closed at an opposite end, wherein locating 10 the catch includes positioning the catch in the casting cavity so that the surface abuts against a portion of the mould to allow the surface of the catch to be flush with a resulting inside surface of the concrete pit box, the catch also adapted to engage a cross-bar when the concrete 15 pit box is in use; placing one or more core blocks in the casting cavity adjacent the catch, wherein at least one of the one or more core blocks is placed adjacent the one end of the catch that is open to provide an access passage to enable 20 the cross-bar to be inserted into and removed from the catch; filling the casting cavity with concrete; when the concrete has sufficiently set to form the concrete pit box, separating the concrete pit box from the 25 mould; and, removing the or each core.

2. The method according to claim 1, further comprising supporting the catch on or in the mould. 30

3. The method according to claim 2, wherein supporting the catch comprises attaching the catch to the mould with a mechanical fastener. 35

4. The method according to claim 2 or claim 3, wherein supporting the catch comprises placing a block in the casting cavity and seating the catch on the block. 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 12 5. The method according to any one of claims 1 to 4, further comprising providing the catch as two separate catch portions.

5

6. The method according to claim 5, wherein locating the catch comprises locating the catch portions at diametrically opposed locations in the casting cavity. 10

7. The method according to any one of claims 1 to 6, further comprising placing a reinforcing structure in the casting cavity prior to filling the casting cavity with concrete. 15

8. The method according to claim 7, further comprising attaching the catch or catch portions to the reinforcing structure.

9. The method according to claim 7 or 8, further 20 comprising forming the catch with a coupling and wherein the attaching of the catch to the reinforcing structure comprises attaching the coupling to the reinforcing structure. 25

10. The method according to any one of claims 1 to 9, wherein forming the mould comprises forming an inner mould, forming an outer mould, and juxtaposing and/or coupling the inner mould to the outer mould to form the casting cavity, wherein locating the catch includes 30 positioning the catch in the casting cavity so that the surface provided with the opening abuts against a portion of the inner mould.

11. The method according to claim 10, wherein supporting 35 the catch on or in the mould comprises supporting the catch on the inner mould. 6538613_1 (GHMatters) P63611.AU.1 ROSG 27/05/15 - 13

12. A concrete component of a pit when made in accordance with the method according to any one of claims 1 to 11.

13. A concrete pit box component comprising: 5 a concrete structure defining an opening and having an outside surface that extends about an outside of the opening and an inside surface that extends about an inside of the opening; and, a catch embedded in the concrete structure, the catch 10 having a surface that is flush with the inside surface and is provided with an opening that is open at one end and closed at an opposite end, the catch also adapted to engage a cross-bar when the concrete pit box is in use; the concrete component further comprising an access 15 passage formed in the inside surface adjacent the one end of the opening to enable the cross-bar to be inserted into and removed from the catch.

14. The concrete pit box component according to 13, 20 wherein the access passage comprises a surface that slopes downwardly toward a centre of a space surrounded by the component.

15. The concrete pit box component according to claim 13 25 or 14, wherein the catch comprises two catch portions, each of which is embedded in the concrete structure and provided with an opening.

16. The concrete pit box component according to claim 15, 30 wherein the opening is in the form of a slot.

17. The concrete pit box component according to any one of claims 13 to 16, further comprising a second catch embedded in the concrete structure on a side not 35 containing the catch, the second catch having a surface that is flush with the inside surface of the concrete structure and is provided with a second opening. 6545187_1 (GHMatters) P63611.AU.1 ROSG - 14

18. The concrete pit box component according to claim 17, wherein the second catch extends for a full length of the side of the concrete structure in which it is embedded. 5

19. The concrete pit box component according to claim 18, wherein the second opening in the second catch is in the form of a slot.

20. The concrete pit box component according to any one 10 of claims 17 to 19, wherein the second catch is in the form of a channel having an opening that opens onto the inside surface of the concrete component.

21. The concrete pit box component according to any one 15 of claims 17 to 20, wherein the second catch is one of two second catches, respective second catches being embedded in different side walls of the concrete component.

22. The concrete pit box component according to any one 20 of claims 13 to 21, wherein the concrete component comprises a pit box or a pit collar.

23. The method or the concrete pit box component substantially as herein described with reference to and as 25 illustrated in the accompanying drawings. 6545187_1 (GHMatters) P63611.AU.1 ROSG