GB2331039A - Moulding railway sleepers with partially embedded inserts - Google Patents

Abstract

A method of moulding a concrete article with a part of an insert (11) embedded in the concrete comprises the steps of providing an insert holding member (20) having a recess (22), assembling the insert and holding member such that the part (17) of the insert to be embedded in the concrete projects from the recess of the holding member, providing a mould (14) having a moulding cavity, the mould (14) having means (25) to support the holding member (20) and insert assembly relative to the moulding cavity, supporting the holding member and insert assembly relative to the moulding cavity, introducing concrete into the moulding cavity, permitting the concrete to set, and removing from the mould (14) the concrete article with the part of the insert embedded in the concrete. The method is suitable for casting railway sleepers.

Description

Title: Method of Moulding a Concrete Article Description of invention This invention relates to a method of moulding a concrete article with a part of an insert embedded in the concrete and more particularly but not exclusively to a method of moulding a concrete railway sleeper with an integral insert known as a shoulder, which is used to engage with a fastening for securing a rail to the sleeper.

Conventionally moulds for use in such a method have comprised a moulding cavity having an opening in which a part of the shoulder which in use engages with the fastening, is received, with a part of the insert projecting into the moulding cavity and becoming embedded in the concrete as the concrete is introduced.

This requires that each mould has a fixed support means with which the shoulder co-operates, and usually a locking means too, so that the shoulder is securely supported relative to the moulding cavity. To ensure rigid support of the insert, the fixed support means/locking means is configured to co-operate with a shoulder or insert of a particular configuration and thus the mould cannot be used without substantial modification to mould the same concrete article but with an insert or shoulder of an alternative configuration.

It will be appreciated that moulds for moulding railway sleepers are relatively large and consequently expensive, and that is essential for shoulder inserts to be accurately located relative to the moulding cavity so that, for example, the distance between a pair of inserts is accurate.

According to a first aspect of the invention we provide a method of moulding a concrete article with a part of an insert embedded in the concrete comprising the steps of providing an insert holding member having a recess, assembling the insert and holding member such that the part of the insert to be embedded in the concrete projects from the recess of the holding member, providing a mould having a moulding cavity, the mould having means to support the holding member and insert assembly relative to the moulding cavity, supporting the holding member and insert assembly relative to the moulding cavity, introducing concrete into the moulding cavity, permitting the concrete to set, and removing from the mould the concrete article with the part of the insert embedded in the concrete.

Thus the method enables a mould to be used to produce similar concrete articles but with different configurations of insert, although a relatively inexpensive insert holding member will be required for each different kind of insert. Moreover, the insert can be rigidly supported relative to the moulding cavity so that quality-reliable concrete articles may consistently be produced.

To achieve this, the recess of the insert holding member may be provided with formations complimentary to formations of the insert, and the method may include the step of engaging the complimentary formations of the insert and holding member as the insert and holding member are assembled together, and additionally, the holding member and the support means of the mould may have complimentary formations, the method comprising engaging the complimentary formations of the holding member and the mould thus to support the holding member relative to the moulding cavity as the concrete is introduced into the moulding cavity.

Preferably the method includes, prior to introducing the concrete into the mould, applying a locking means between the holding member and the mould to secure the holding member and insert relative to the moulding cavity, and subsequently releasing the locking means to permit the holding member to be removed from the mould. One such locking means may comprise a locking pin which is inserted into a passage in the holding member and the mould to secure the holding member. In order to exert a holding force, the method may include urging the holding member towards its supported position by inserting the locking pin in the passage.

It will be appreciated that in order to remove the moulded concrete article from the moulding cavity it would be necessary to release the locking means, and thus if desired, on removal of the concrete article from the moulding cavity the holding member is removed too, the method including the step of subsequently separating the holding member and insert.

According to a second aspect of the invention we provide an apparatus for moulding a concrete article having an insert at least partly embedded in the concrete, the apparatus comprising a mould affording a moulding cavity, a holding member for holding an insert, the holding member having a recess in which the insert is receivable such that the part of the insert to be embedded in the concrete projects from the recess, and a support means fixed relative to the mould for supporting the holding member relative to the moulding cavity such that as concrete is introduced into the moulding cavity, the projecting part of the insert becomes embedded in the concrete.

Such an apparatus may include locking means for locking the holding member to the support means. The recess of the insert holding member may be provided with formations complimentary to formations of the insert, the formations being engageable to assemble the insert and holding member.

Further, the holding member and the support means of the mould may have complimentary formations which are engageable to provide support for the holding member.

Although the invention is generally applicable to the moulding of concrete articles with inserts, the invention has particular application where the concrete article is a railway sleeper in which case the mould may be designed particularly for casting a concrete railway sleeper, the insert being part of a rail fixing system for holding a rail relative to the sleeper.

The invention will now be described with reference to the accompanying drawings in which FIGURE 1 is an exploded perspective view of part of an apparatus for moulding a concrete article by the method of the invention.

FIGURE 2 is a side sectional view through the apparatus of Figure 1 shown assembled.

Referring to the drawings there is shown an apparatus 10 for moulding a concrete article with part of an insert 11 embedded in the concrete. In this example, the article to be moulded is a concrete railway sleeper, and the insert 11 is a device known as a "shoulder" which is used to engage with a fastening for securing a rail to the concrete sleeper.

The invention utilises a mould 14, only part of which is shown, which for this concrete article is of generally elongate configuration, there being toward each end of the mould 14 an opening 15 for receipt of at least part of the insert 11 during moulding. The mould 14 is of generally box-like construction, having a bottom 13, two side walls 16a, 16b and two end walls 16c, only one of which is shown in the broken away drawing.

Conventionally, within the opening 14 a support means would be provided for supporting the insert 11 in an appropriate orientation, such that a fixing part 17 of the insert 11 projects from the opening 15 upwardly into the moulding cavity of the mould 14, whilst the operative parts 18 of the insert 11 which in use co-operate with a fastening for securing a rail to the sleeper, are received within the opening 15 exterior to the moulding cavity. However, in accordance with the invention, there is provided an insert holding member 20 which may be made from engineering plastic, cast iron, aluminium or similar materials, or any other suitable metallic or non-metallic materials.

The insert holding member 20 provides a recess 22 of a configuration corresponding to the configuration of the operative part 18 of the insert 11.

Projecting inwardly of the recess 22 are a pair of formations 23 and thus it can be seen that the insert 11 is received in the recess 22 by a sliding movement in the direction of arrow A during which the inwardly extending formations 23 of the recess 22 are received in corresponding formations (slots) 24 of the insert 11 such that the insert 11 is retained in the recess 22 against movement relative to the insert holding member 20 in a direction transverse to direction of arrow A.

The opening 15 in the mould 14 comprises and inwardly extending nose 25 and the insert holding member 20 has a corresponding formation 26. Thus it will be appreciated that the insert holding member 20, with the insert I 1 assembly therewith, can be lowered into the opening 15 with the nose formation 25 of the opening 15 received in the corresponding formation 26 of the holding member 20. Beneath the nose formation 25 of the opening 15, there is provided a first locating member 28 which engages with a rear face 29 of the holding member 20 in which the nose co-operating formation 26 is provided. Also, within the opening 15 there is provided a second locating member 29. As the assembling holding member 20 and insert 11 are lowered into the opening, a flange part 30 of the holding member 20, or in an alternative arrangement a part of the insert itself will eventually come to rest on the second locating member 29 and thus further downward movement of the holding member 20 through the opening 15, is arrested.

Preferably the opening 15 is a through opening through the bottom wall 13 of the mould 14 so that during casting, any concrete with may enter the opening 15, can fall though the bottom wall 13 of the mould 14 and hence not accumulate in the opening 15.

It will be appreciated that the locating members 28 and 29 need accurately to be positioned within the opening 15 of the mould 14 in order to support the holding member 20 and most importantly the insert 11, in a predetermined position in the mould 14 particularly such that the distance between the pair of inserts 11 is within acceptable tolerances, because this distance governs the gauge of the railway track of which the concrete sleeper is apart.

To provide added security for the positioning of the insert 11 a locking means is provided which comprises a locking pin 30. It can be seen that the side walls 16a and 16b of the mould 14 are provided with openings 31 and that the insert holding member 20 to has a through opening 32. When the opening 32 of the holding member 20 and the openings 31 of the side walls 1 6a and 1 6b of the mould 14 are in alignment, the locking pin 30 may be inserted thus to prevent the holding member 20 being removed from the opening 15 in a direction transversed to arrow A. preferably the openings 31, 32 are positioned, and the pin 30 is of a configuration such that as the pin 30 is inserted into a passage formed by the openings 31, 32, an urging force is applied to the holding member 20 to urge the holding member 20 downwardly through the opening 15 thus to bling the flange 30 and locating member 29 and rear face 29 and locating member 28 at least, into tight engagement.

In this way, a rigid secure attachment of the holding member 20 in the mould 14 can be achieved and furthermore, by virtue of the insert 11 being a sliding fit into the recess 22 of the holding member 20, the nose formation 25 of the opening 15 will prevent sliding movement of the insert 11 in a direction opposite to arrow A once the holding member 20 is located in the opening 15 of the mould 14.

When both inserts 11 towards each end of the mould 14 are thus supported relative to the moulding cavity, concrete may be introduced into the moulding cavity eg. by casting, and then the mould 14 may be vibrated as is well known in the art, to settle the concrete. The concrete may then be allowed to set for a desired period of time.

In order to remove the concrete sleeper from the moulding cavity of the mould 14 it will be appreciated that first the locking pins 30 holding the holding members 20 need to be removed. Then the concrete article can be removed from the mould 14 and subsequently the holding member 20 of each insert 11 may be separated from the inserts 11 and discarded, or cleaned for further use.

If desired, a sealing means may be provided over the insert 11 to cover any gap there may be between the periphery of the opening 15 in the mould, and the holding member 20, in order to inhibit concrete entering the opening 15 during moulding.

Various modifications may be made without departing from the scope of the invention. For example, the co-operating formations 23 of the holding member and 24 of the insert 11 may be of alternative configurations depending upon the nature of the insert 11. Also, the arrangement of locking members 29 and the nose formation 25 of the opening, may be otherwise arranged in order to provide support for the holding member 20 when inserted into the opening 15 ofthe mould 14.

Instead of a locking pin 30 and passage provided by openings 31, 32 in the mould 14 and holding member 20, an alternative form of locking means may be provided to lock the holding member 20 in support in relation to the moulding cavity.

It will be appreciated that by virtue of the invention it is possible to use the mould 14 to mould a concrete article with a wide variety of alternative insert 11 configurations, by arranging for a holding member 20 of a different configuration to co-operate with the insert 11, but having the same configuration of formations to co-operate with the support means provided in the opening 15. Thus the invention provides considerable economic advantage over existing methods and, in the example described, in which the insert 11 is a sliding fit with the holding member 20, which has not hitherto before been possible, because otherwise it would not have been possible to remove the concrete article from the mould, considerable stability of the insert 11 during moulding can be achieved.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (15)

1. CLAIMS 1. A method of moulding a concrete article with a part of an insert embedded in the concrete comprising the steps of providing an insert holding member having a recess, assembling the insert and holding member such that the part of the insert to be embedded in the concrete projects from the recess of the holding member, providing a mould having a moulding cavity, the mould having means to support the holding member and insert assembly relative to the moulding cavity, supporting the holding member and insert assembly relative to the moulding cavity, introducing concrete into the moulding cavity, permitting the concrete to set, and removing from the mould the concrete article with the part of the insert embedded in the concrete.
2. 2. A method according to claim 1 wherein the recess of the insert holding member is provided with formations complimentary to formations of the insert, the method including the step of engaging the complimentary formations of the insert and holding member as the insert and holding member are assembled together.
3. 3. A method according to claim 1 or claim 2 wherein the holding member and the support means of the mould have complimentary formations, the method comprising engaging the complimentary formations of the holding member and the mould thus to support the holding member relative to the moulding cavity as the concrete is introduced into the moulding cavity.
4. 4. A method according to claim 3 wherein the method includes, prior to introducing the concrete into the mould, applying a locking means between the holding member and the mould to secure the holding member and insert relative to the moulding cavity, and subsequently releasing the locking means to permit the holding member to be removed from the mould.
5. 5. A method according to claim 4 wherein the locking means comprises a locking pin which is inserted into a passage in the holding member and the mould to secure the holding member.
6. 6. A method according to claim 5 wherein the method includes urging the holding member towards its supported position by inserting the locking pin in the passage.
7. 7. A method according to any one of the preceding claims wherein on removal of the concrete article from the moulding cavity the holding member is removed too, the method including the step of subsequently separating the holding member and insert.
8. 8. A method of moulding a concrete article substantially as herinbefore described with reference to the accompanying drawings.
9. 9 An apparatus for moulding a concrete article having an insert at least partly embedded in the concrete, the apparatus comprising a mould affording a moulding cavity, a holding member for holding an insert, the holding member having a recess in which the insert is receivable such that the part of the insert to be embedded in the concrete projects from the recess, and a support means fixed relative to the mould for supporting the holding member relative to the moulding cavity such that as concrete is introduced into the moulding cavity, the projecting part of the insert becomes embedded in the concrete.
10. 10. An apparatus according to claim 9 further comprising locking means for locking the holding member to the support means.
11. 11. An apparatus according to claim 9 or claim 10 wherein the recess of the insert holding member is provided with formations complimentary to formations of the insert, the formations being engageable to assemble the insert and holding member.
12. 12. An apparatus according to any one of claims 9 to 11 wherein the holding member and the support means of the mould have complimentary formations which are engageable to provide support for the holding member.
13. 13. An apparatus according to any one of claims 9 to 12 wherein the mould is for casting a concrete railway sleeper and the insert is part of a rail fixing system.
14. 14. An apparatus for moulding a concrete article substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
15. 15. Any novel feature or novel combination of features hereinbefore described and/or as show in the accompanying drawings.