GB2328176A - A moulding apparatus for a concrete article having an insert - Google Patents

Abstract

A moulding apparatus (10) for a concrete article having an insert (12) comprises a moulding cavity (17) in which the concrete is cast and means (15) to support the insert (12) relative to the cavity (17) such that when the concrete is cast, at least part of the insert (12) becomes embedded in the concrete, the support means (15) comprising at least one resiliently biased latch (14) having a nose part (22) which in use engages a support formation of the insert (12) and thus urges the insert (12) towards its supported position (Fig 3). The apparatus is used for casting railway sleepers.

Description

Title: A Moulding Apparatus for a Concrete Article Having An Insert This invention relates to a moulding apparatus for a concrete article having an insert, and to a method of moulding such an article.

More particularly but not exclusively the invention relates to a moulding apparatus and method for casting concrete articles comprising railway sleepers, with integral inserts known as shoulders, which are used to engage with a fastening for securing a rail to the sleeper.

Conventional shoulders have had an opening in which a fixing pin has been received to support the shoulder relative to a casting cavity of the mould as the concrete is cast and the concrete is vibrated to remove voids.

However recent developments in fastening systems have led to radical redesign of the shoulder configuration with the result that no appropriate opening is provided in the newer shoulder designs.

Accordingly the invention has been developed to enable such newer shoulder designs to be supported relative to a casting cavity during concrete casting, by means which are robust and simple to operate in a concrete factory environment.

According to a first aspect of the present invention we provide a moulding apparatus for a concrete article having an insert the apparatus comprising a moulding cavity in which the concrete is cast and means to support the insert relative to the cavity such that when the concrete is cast, at least part of the insert becomes embedded in the concrete, the support means comprising at least one resiliently biased latch which in use engages a support formation of the insert thus to urge the insert towards its supported position.

It is important particularly where the invention is applied to the casting in concrete of sleepers for a railway track that the insert (s) is/are supported securely because the positions of the inserts along a sleeper define the gauge of the railway track. By utilising at least one spring biased latch, the insert may be held securely so that the insert does not move as the concrete is cast and the mould is vibrated to consolidate the concrete.

More preferably the resiliently biased latch is rotatable about an operating axis. Thus engagement and disengagement of the latch with the insert is facilitated by rotating the latch against its resilient biasing out of engagement with the support formation of the insert. Also, the use of a resiliently biased rotatable latch enables variations in the shoulder to be accommodated, e.g. of the position/configuration of the support formation with which the latch is in use engaged, whilst maintaining positive pressure (urging) on the insert to support the insert in position.

Although alternative designs of resiliently biased rotatable latch are possible, preferably resilient biasing means are provided which act linearly resiliently to bias the latch about the operating axis. The latch may comprise a nose portion which in use is resiliently biased into engagement with the support formation of the latch to urge the insert towards its supported position.

Where the insert is of an appropriate configuration, a pair of resiliently biased latches may be provided which each engage with a respective support formation of the insert to urge the insert towards its supported position relative to the cavity. For example, the moulding apparatus may comprise a support assembly in which the insert may be received when the pair of latches are moved against their resilient biasing means, the assembly including one or more support surfaces towards which the insert is urged in use by the latches.

Although the invention may be more generally applied, the concrete article may typically be a concrete sleeper for a railway track and the insert a shoulder for engagement with a fastening for affixing the sleeper relative to a rail.

According to a second aspect of the invention we provide a method of moulding a concrete article having an insert the method comprising the steps of supporting the insert relative to a casting cavity of the moulding apparatus in a position such that when the concrete is cast, at least part of the insert becomes embedded in the concrete, the method comprising engaging at least one resiliently biased latch of a support means with a support formation of the insert such that the insert is urged by the resiliently biased latch towards its supported position.

The method may utilise at least one resiliently biased latch which has, or latches which have, any of the features of the apparatus of the first aspect of the invention.

The invention will now be described with reference to the accompanying drawings in which: FIGURE 1 is an illustrative view of a moulding apparatus in accordance with the invention prior to insertion of an insert in a support assembly of a mould; FIGURE 2 is a more detailed but still illustrative end view of the apparatus of figure 1, showing the insert in a position just prior to insertion into the supporting assembly; FIGURE 3 is a view similar to that of figure 2 but showing the insert supported in position.

Referring to the drawings there is shown a moulding apparatus 10 for moulding in this example, an elongate concrete article comprising a concrete railway sleeper. Such concrete railway sleepers have a plurality (usually at least two) inserts 12 moulded integrally with the concrete of the sleeper, the inserts 12 comprising part of a rail fastening system by which a, usually metal, rail is attached to the railway sleeper.

It will be appreciated therefore that positioning of the at least two inserts 12 is crucial as the positioning of the inserts 12 defines the gauge of the railway track.

In a factory environment where concrete articles are made it is essential that any moulding apparatus 10 is robust and simple to operate and that the apparatus is able consistently to be used to produce concrete articles to the required quality.

In accordance with the invention the moulding apparatus 10 utilises a pair of resiliently biased latches 14 for each insert 12, which latches 14 in use urge each insert 12 to a supported position in a support assembly 15.

More particularly, the support assembly 15 comprises a frame like construction which has therein, support surfaces 16 for supporting the insert 12.

The support assembly 15 is preferably made of metal for rigidity, but having plastic parts such as coverings in positions where concrete contacts the assembly 15, for ease of separation of the assembly 15 and concrete when the concrete has set. The support assembly 15 is positioned in or adjacent to the casting cavity 17 of the moulding apparatus 10 in which concrete is cast. In the present example, where the insert 12 is a shoulder for a rail fastening system, a pair of such support assemblies 15 would be provided at spaced positions along the elongate casting cavity 17.

In this example, the insert 12 is positioned upside-down in the moulding apparatus 10 compared with the orientation of the insert 12 in use, and the sleeper is cast upside-down. It will be appreciated by those skilled in the art of railway sleeper manufacture that the insert 10 will in use in a railway track, be located so as to extend from the top of the sleeper. To this end the insert 12 has fixing formations 18 which are.within the support assembly 15 outside the casting cavity 17 as the concrete is cast, so that such fixing formations 18 may, in use, be free to be engaged with a clip of a fastening system by which the rail of the track is secured to the sleeper.

In the example described, the insert 10 has a fixing part 20 which during casting, extends into the casting cavity 17 and thus becomes embedded in the concrete as the concrete is cast into the casting cavity 17 of the moulding apparatus 10.

To enable the insert 12 to be received in the support assembly 15, the rotatable resiliently biased latches 14 are rotated about a common operational axes A, against the force of their resilient biasing, such that nose parts 22 thereof permit support formations 23 of the insert 12 to move towards the positions they will occupy during casting, as shown in figure 3. The support surfaces 16 of the support assembly 15 will thus engage with the insert 12.

The latches 14 are then released and will move about their respective operational axes A,B to the positions shown in figure 3 when the nose parts 22 of the latches 14 will engage on top of the support formations 23 at either side of the insert 12 to urge the insert 12 towards its supported position and thus rigidly to hold and support the insert 12 in its correct position relative to the casting cavity 17, constrained also by the co-operation of the support surfaces 16 of the support assembly 15 and the corresponding parts of the insert 12.

With a pair of the inserts 12 supported in their correct positions relative to the casting cavity 17, concrete may then be cast together with any reinforcement, into the casting cavity 17. When the concrete has set, the cast concrete railway sleeper with the or each insert cast integrally therewith, may be removed from the moulding apparatus 10 for use, by rotating each of the latches 14 against their resilient biasing back to the positions shown in figure 2.

It can be seen from the figures that in this example, the latches 14 each comprise in addition to the nose parts 22 which engage with the inserts 12, a linearly acting spring 25 which preferably is encased for protection, which spring 25 acts on a bearing surface 26 of the latch 14 resiliently to bias the latch 14 about its operating axis A in a sense of rotation to bring the nose parts 22 towards and into engagement with the tops of the support formations of the insert 12. In another example, other arrangements are no doubt possible.

In another example where the invention is applied to an alternative configuration of insert 12 for a railway sleeper, or to another concrete article altogether, modification of the moulding apparatus 10 may be necessary. In such an event, it may be essential to have one only resiliently biased latch 14 instead of two the example described and shown in the drawings. Of course in place of the linearly acting springs 25 some alternative mechanism for resiliently biasing the latches 14 may be used although the arrangement described has the advantage of not unduly increasing the overall depth of the moulding apparatus 10.

If desired, the fixing part 20 of the insert 12 may be of a different configuration to that shown although the configuration described, which includes flanges 30, provides for a particularly rigid fixing with the concrete of the sleeper.

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 folms thereof.

Claims (12)

1. A moulding apparatus for a concrete article having an insert the apparatus comprising a moulding cavity in which the concrete is cast and means to support the insert relative to the cavity such that when the concrete is cast, at least part of the insert becomes embedded in the concrete, the support means comprising at least one resiliently biased latch which in use engages a support formation of the insert thus to act to urge the insert towards its supported position.

2. An apparatus according to claim 1 wherein the resiliently biased latch is rotatable about an operating axis.

3. An apparatus according to claim 2 wherein resilient biasing means act linearly resiliently to bias the latch about the operating axis.

4. An apparatus according to claim 2 or claim 3 wherein the latch comprises a nose part which in use is resiliently biased into engagement with the support formation of the latch to urge the insert towards its supported position.

5. An apparatus according to any one of the preceding claims wherein a pair of resiliently biased latches are provided which each engage with a respective support formation of the insert to urge the insert towards its supported position relative to the cavity.

6. An apparatus according to claim 5 wherein the moulding apparatus comprises a support assembly in which the insert may be received when the pair of latches are moved against their resilient biasing means , the assembly including one or more support surfaces towards which the insert is urged in use by the latches.

7. An apparatus according to any one of the preceding claims wherein the concrete article is a concrete sleeper for a railway track and the insert is a shoulder for engagement with a clip for affixing the sleeper relative to a rail.

8. An apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

9. A method of moulding a concrete article having an insert the method comprising the steps of supporting the insert relative to a casting cavity of the moulding apparatus in a position such that when the concrete is cast, at least part of the insert becomes embedded in the concrete, the method comprising engaging at least one resiliently biased latch of a support means with a support formation of the insert such that the insert is urged by the resiliently biased latch towards its supported position.

10. A method according to claim 9 in which the at least one resiliently biased latch has, or the latches have, any of the features of the apparatus of any one of claims 1 to 8.

11. A method of moulding a concrete article having an insert substantially as hereinbefore described with reference to the accompanying drawings.

12. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.