GB2278387A

GB2278387A - A plastics pipe sleeve for lining an access hole

Info

Publication number: GB2278387A
Application number: GB9409836A
Authority: GB
Inventors: Yock Kuan Tan
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-05-21
Filing date: 1994-05-17
Publication date: 1994-11-30
Anticipated expiration: 2014-05-17
Also published as: GB2278387B; CN1100487A; GB9409836D0

Abstract

A plastics sleeve (10) comprises 2 hollow open-ended cylindrical body (11) with a plurality of circumferential rib elements (12) on its outside wall and radial stiffener members (30), to span one said open end. A circumferential rib element (12a, 12d) rims either open end of the sleeve (10) with at least one of them being provided with a plurality of equidistantly spaced fastening locations (13). A central hole (31) in the hub of the stiffener members can act as an aid to alignment of sleeves on adjacent floors of a building. <IMAGE>

Description

A PLASTIC PIPE SLEEVE AND ITS METHOD OF INSTALLATION TECHNICAL FIELD The invention relates to a device for leaving an access hole through a concrete floor slab, for subsequent connecting of pipes, and particularly relates to a plastic pipe sleeve with improved features.

PRIOR ART Prior art plastic pipe sleeves are used to leave an access hole in the concrete floor slab for subsequent connection of soil or waste or vent pipes adjoining different floors.

These pipe sleeves are first fastened-up on a formwork usually made of plywood before casting the concrete into a floor slab. The prior art pipe sleeves have several disadvantages. The inside and outside walls of the prior art pipe sleeve are uninterrupted and straight. Leakage of water from a floor above often seeps down the outside wall of the pipe sleeve. This can have several undesirable and unhygienic consequences. Another disadvantage is that it is difficult to align and join a second pipe adjoining a separate floor since there is no reference centre point readily and positively indicated on said prior art pipe sleeve.

SUMMARY OF THE INVENTION It is the object of the invention to provide a simple means of obstructing and interrupting the contour of the outside wall of the pipe sleeve.

It is also the object of the invention to provide a means of defining a reference centre point in the pipe sleeve.

To achieve the above objects, the outside wall of the pipe sleeve is integrally formed with a plurality of circumferential rib elements. A means of centre point indication is achieved by the provision of an integral pattern of stiffener elements with a central ringed hole, which detachably spans one open end of the pipe sleeve.

The invention with its leading features is described below in different embodiments with the aid of the drawings in which: Figure (la) is a side elevation view of one preferred embodiment of the invention, showing a partial cross section of its body.

Figure (lb) is a top view of the invention as shown in Figure (la).

Figure (2) is a cross-section view of the invention after it has been installed according to one preferred method of installation.

Figure (3) shows the formwork shown in Figure (2) detached from the invention, after a concrete floor slab is formed.

Figure (4) is a view of a plumb line being used to align a reference centre point of a first pipe sleeve with a second pipe sleeve.

Figure (5a) is a side view of a second embodiment of the invention, with the planetary fastening locations away from the integral pattern of stiffener elements.

Figure (5b) is a side view of the invention as shown in Figure (5a) ready for installation according to.an alternate method of using it upside down.

DETAILED DESCRIPTION One preferred embodiment of the invention designated as (10) serves to leave an access hole in a concrete floor slab for subsequent connection of pipes. The invention is illustrated by way of example in Figures (la) and (lob). It is substantially a pipe sleeve with an open-ended hollow cylindrical body (11). There are four circumferential rib elements formed on the outside wall of said body. Two of these are intermediate (12b, 12c) and two (12a, 12d) are terminal, adjacent to each opening of said body (11). The bottom terminal rib element (12d) is additionally provided with four fastening locations (13a, 13b, 13c, 13d) equidistantly spaced around the bottom opening.

For ease of description, common numerals are used to denote similar features on the invention. To differentiate and identify each individual component, a small letter of the alphabet is optionally added after the common numeral. It is important to note that four fastening locations, four rib elements and four stiffener elements are preferably shown in Figures (la) and (lb). However, a combination of numbers ranging from three to seven can be used advantageously for the various components mentioned above.

In the centre of the integral pattern (30) of the stiffener elements, there is a reference centre hole (31). An engagement means such as a wood screw (40) passes through this hole to hold the invention onto an underlying formwork (50) preferably made of plywood. Where the stiffener elements (30) engage the inner wall of the cylindrical shell body (11), the thickness at the joint is weakened and reduced (32). This allows the integral pattern to be detached from inside the shell body after a concrete floor slab (60) has set and the plywood formwork (50) is removed.

It is advantageous for the joints (32) to be slightly above the bottom opening of said shell body. The space is preferably in the range of 1 to 8 mm. It is further advantageous for the bottom side of the stiffener elements (30a, 30b, 30c, 30d) to be substantially flush with the underlying formwork (50). This is to ensure correct and firm positioning of the pipe sleeve (10) when concrete casting is in progress. The outside wall of the sleeve body (11), excluding the rib members (12), is preferably roughened, so as to increase the efficacy of concrete bonding.

One preferred method of installation is illustrated in Figures (2) and (3). A point is marked on the formwork (50) where a pipe is intended to pass through a concrete floor slab (60). A nail is used to punch a small hole through the said point. The pipe sleeve (10) is placed on top of the formwork (50) where its reference centre hole (31) is in alignment with the above-mentioned punched hole.

A wood screw (40) is used to fasten the pipe sleeve (10) onto the formwork (50). To further strengthen the holding action, nails are driven through the planetary fastening locations (13) adjacent to the bottom opening of the shell body (11).

After the concrete is cast and set, the formwork (50) is removed and the integral pattern of stiffener elements (30) is detached by force. The excess plastic material remnant at the joints (32) can be filed away before subsequent pipe connection.

In order to have a leak-free discharging flow system of soil or waste pipes adjoining different floors in a building, it is important to align the centre points of connecting pipes. Referring to Figure (4), an access hole has already been left in a concrete floor. A short length of an extension pipe is placed into said access hole. A second pipe sleeve is placed on top of the extension pipe, so that the centre hole (31) in the pattern of stiffener members (30) defines the centre point of the pipe. A plumb line is adjustably hung from a second formwork (50) above the said floor and then nailed up when alignment is achieved with the base centre point of the pipe. Once this point is marked on the second formwork, a second pipe sleeve is used to leave an access hole in the second concrete floor slab.

Figure (5a) illustrates , a second embodiment where the fastening locations (13) are provided at the other opening of the cylindrical shell body (11) away from the pattern of stiffener elements, (30). To secure the second embodiment onto the formwork (50) in this first orientation, four wires are additionally used to hold the fastening locations (13).

Figure (5b) illustrates an alternate method of inverting it and installing the pipe sleeve (10) with modifications shown in Figure (5a). In this second orientation, the integral pattern of stiffener elements (30) is above the bottom opening. The fastening locations (13) are driven directly onto the underlying formwork (50) by nails.

It is apparent to those skilled in the art that other modifications can be made to-the preferred embodiments and alternate methods of installation are also possible following said modifications. All these modifications should be read within the scope of the present disclosed invention.

Claims

1. A sleeve comprising: a cylindrical body with two open ends; a plurality of circumferential rib elements on its cylindrical outside wall; and a pattern of stiffener members defining a hole on the axis of said sleeve.

2. A sleeve as claimed in claim 1, wherein the sleeve is for use in connection of utility pipes.

3. A sleeve as claimed in claim 1 or claim 2, wherein the stiffener members are detachable.

4. A sleeve as claimed in claim 3, in which the sleeve includes a weakened joint between the stiffener members and the inside wall of said sleeve to enable the stiffener members to be detached.

5. A sleeve as claimed in any preceding claim, wherein the sleeve is made from plastics material.

6. A sleeve as claimed in any preceding claim, wherein one circumferential rib element is integrally located to circle each terminal opening of the sleeve whereas at least one such terminal rib element is provided with a plurality of fastening locations equidistantly placed around the opening.

7. A sleeve as claimed in claim 6, wherein the pattern of. stiffener members is located at the same level as the terminal rib element which is provided with a plurality of planetary fastening locations.

8. A sleeve as claimed in claim 6 or claim 7, in which there are preferably four fastening locations.

9. A sleeve as claimed in any preceding claim, wherein the pattern of stiffener members forms a cross shape, and the axis of the sleeve corresponds to the intersection of the members.

10. A sleeve as claimed in any preceding claim, wherein the pattern of members is joined integrally to the inside wall of the cylindrical body.

11. A sleeve as claimed in any preceding claim, wherein the stiffener members are joined to the inside wall of the cylindrical body at a distance of preferably Imm to 8mm from one opening of said sleeve.

12. A sleeve as claimed in any preceding claim, in which the outside wall of said sleeve body, excluding the rib elements, is roughened.

13. A sleeve substantially as described herein with reference to Figs. 1 to 4 or Figs. 5a and 5b of the accompanying drawings.

14. A method of installing a sleeve as claimed in any preceding claim includes the step of retaining said sleeve on a formwork, either by a screwing through the centre hole of the pattern onto said formwork, or nailing through fastening locations around the cylindrical body, the step of pouring concrete around the sleeve, the step of removing the formwork after the concrete has set, and the step of breaking off the pattern at weakened joints thereof.

15. A method of installing said sleeve as claimed in claim 14, in which the centre hole of the pattern is referenced in defining and locating the next centre point for a subsequent similar sleeve adjoining separate floors.

16. A method of installing a sleeve substantially as described herein with reference to Figs. 1 to 4 or Figs. 5a and 5b of the accompanying drawings.