IE56074B1 - Device for securing a mounting element to a mould - Google Patents

Abstract

In order to fasten a screwed dowel on a formwork mould in the production of concrete compound units, a retaining pipe (8) which penetrates the wall (2) of the formwork mould (1) and is connected thereto is provided, in the widened bore (14) of which a tubular tensioning element (15), made of flexible material and continuing said bore in the longitudinal direction, is inserted. A tensioning cable (19), which is anchored at the upper end of the tensioning element (15) by a ball (21), passes through the tensioning element (15) and retaining pipe (8). By exerting a tensile force on the cable (19), the tensioning element (15) is compressed in its free area and a dowel (4), placed on the tensioning element and the retaining pipe, is thus pressed against the wall (2) of the formwork mould (1) and fixed.

Description

DYCKERHOFF ft UIDMANN AKTXENGESELLSCHAFT, A COMPANY ORGANISED UNDER THE LANS OF TEE FEDERAL REPUBLIC OF GERMANY, OF ERDINGER LAHDSTRASSE 1, 8000 MUNCHEN 81, FEDERAL REPUBLIC OF GERMANY.

Price Mp This invention relates to a device for securing a socket-like accessory. It relates in particular to a device for securing to shuttering a socket-like accessory for subsequent casting into or building into a concrete element or component.

When railway sleepers of reinforced or pre-stressed concrete are used in railway lines, the rail securing parts such as plugs, fishplates, anchor bolts or the like, must occupy exactly the places prescribed for them. For that reason plugs, especially in the form of so-called wave plugs of plastics, which later receive the screws for fastening the rails, must be incorporated as built-in accessories in the shuttering mould, at the time of manufacture of the sleepers. These plugs are brought into Intimate attachment to the sleeper body by casting-in, so that they will later withstand, together with the sleeper, the forces which arise under the dynamic stresses of railway operation.

In a frequently employed kind of rail attachment, use is made of a screw plug of plastics as an anchoring means, of which two.per rail, and thus a total of four, have to be concreted into the sleeper body. The sleepers are generally prepared in the reverse of the position of use, i.e., the base of the shuttering moulds the later surface of the sleeper upon which the - 2 parts for rail attachment lie. So as to be able to secure these plugs on the base of the shuttering mould, each plug is first placed separately on a rosette fixed to the shuttering mould, for centering purposes. Then a securing bolt is inserted through the continuous hole of the plug intended for later reception of the screw. One of the ends of this securing bolt penetrates the shuttering mould and the bolt is secured on the mould by clamping, while its opposite end extends beyond the upper edge of the shuttering mould, to permit the bolt to be loosened and removed again from that direction, after the concrete has set. The plug is also pressed securely against its seat on the rosette by means of this through-going securing bolt.

Apart from the fact that every single plug of a sleeper must be secured in this manner, this method of securing is attended by the disadvantage that it is not only the plug that must have a through-hole, in order to permit its penetration by the securing bolt, but that the sleeper body itself also acquires a void reaching as far as what later becomes the underside of the sleeper. The danger thus arises that later, when the sleeper lies in the ballast bed, moisture may be able to penetrate from the underside of the sleeper, which can lead to the appearance of corrosion on the rail securing screws. For that reason, the through-hole for the plug is closed by knocking in a wooden stopper after the concrete body of the sleeper has set, and before the sleeper screws are introduced. Nevertheless, the voids, which weaken the sleeper body, remain therein.

If is an object of the invention to enable the securing of this kind of screw plug to the shuttering mould, while not only reducing the manual labour and corresponding time cost in building-in the plugs, but also eliminating the through-hole.

According to the invention, there is provided a device for securing a socket-like accessory to be built info a component on a part of a shuttering mould which moulds an outer surface in the manufacturing of building components, the device having a tensioning element of elastic material, which can be splayed against the inner wall of the accessory by a transverse expansion produced as a result of axial prssure generated by means of a tension member passing through the tensioning element in its longitudinal direction and fixedly anchorable at an end thereof, wherein the tensioning - 3 element is formed as a tube and comprises an extension for a securing tube for penetrating a wall of the shuttering mould, over which the accessory can be placed, the tube being securable to the wall.

The lower end of the tensioning element is suitably insertable into an enlargement of the longitudinal bore of the securing tube, which forms an abutment.

The securing tube itself consists desirably of a lower and an upper part, the upper part of the securing tube being formed as a socket separated from the lower part by a slit or parting.

The tension member is desirably formed as a cable and is disposed within the tensioning element as well as within the securing tube, in the manner of a bowden cable. At the upper end of the tension or traction member, there is provided an anchor body supported against the end surface of the tensioning element, and usefully formed as a sphere.

The tensioning element can be provided with profiles, e.g. ribs, at least on its peripheral surface which projects from the securing tube or socket.

The essential advantage of the invention lies in the fact that the plug is held from one side, viz. on the base of the shuttering mould, the side on which it must have an opening in any case, for the later admission of the sleeper screw. Thus the plug can not only be closed at the opposite end, but can also be designed shorter, and a through void is no longer necessary in the sleeper body. The closed end of the plug, bedded in the concrete body, is always completely surrounded by concrete, so that moisture can no longer penetrate into the plug.

A further advantage of the device according to the invention is that the axial force necessary for spreading the tensioning element, after the tensioning element has come to rest on the inner wall of the hole through the plug as a result of transverse expansion, is communicated also to the plug, so that it is firmly pressed against the rosette and thereby against the shuttering form, and thus its exact position in the sleeper body is assured. - 4 A further object of the Invention is an arrangement for securing the built-in accessories onto a shuttering mould, in which a securing deice of the type described is assigned to each accessory to be built in, and the cables of the individual securing devices are led to a common actuating device.

The invention is not limited to the building-in of screw plugs in concrete sleepers, but can be applied everywhere hollow built-in parts, e.g. including screw-threaded cores, have to be moulded into concrete building components.

Further features and advantageous properties of the invention will be appreciated from the following description of the embodiment represented in the drawings, in which Figure 1 is a longitudinal section of a shuttering mould for a concrete sleeper with plugs and associated fixing devices, Figure 2 shows the shuttering mould according to Figure 1 with plugs built into it, Figure 3 is a longitudinal section through the finished concrete sleeper with built-in plugs in the position of use, and Figure 4 is a section, on a larger scale, through a securing device along the line IV-IV in Figure 2.

Railway sleepers of reinforced or pre-stressed concrete are usually manufactured in shuttering moulds 1, upside down with reference to their position of use, one such mould being represented in longitudinal section in Figure 1. On the floor 2 of the shuttering there is located, for each rail and spaced apart therefrom, a respective pair of mutually opposed securing devices 3 according to the invention, which are illustrated separately on a larger scale in Figure 4. A screw plug 4 of plastics can be pushed onto each of these spike-like securing devices 3 from above in the direction of the arrow 5.

Figure 4 shows a longitudinal section through a single securing device on a larger scale together with a plug 4 held in tension by the - 5 latter. On the inner side of the base or floor 2 of the shuttering mould 1, a rosette 6 is placed. The rosette 6 has, on its upper side, a profile in conformity with the head 7 of the plug, so as to be able precisely to centre and to fix the latter. The rosette 6 is penetrated by a securing tube or pipe 8, shoulder 9 of which lies upon the rosette, and the tube is located and held fast on the outer side of the shuttering floor 2 by a nut 10. In this manner, the rosette 6 is secured to the shuttering floor 2 together with the securing pipe 8.

The securing pipe 8 has a narrow extension 11, in the region of which the central bore 13 of the securing pipe 8 is widened. Into this widened part 14, there is inserted the lower end of a tubular tensioning element 15 of elastic material, e.g. rubber, plastics or the like, until it comes to rest on an abutment 16 at the end of the widened part 14. The upper part of the securing pipe 8, located above the extension 11, forms a socket 17, which embraces the tensioning element 15 and prevents its expansion in this region. Between the socket 17 and the securing pipe 8, a slit or parting 18 is disposed, which, as a result of the elastic properties of the tensioning element 15, permits a certain play.

A steel cable 19 extends right through the securing pipe 8 and the tensioning element 15, having a clamp 20 secured to its end, which clamp fixes an anchor body 21, lying at the upper end 22 of the tensioning element 15.

When the cable 19 is loose, then the plug 5 can be freely stuck over the tensioning element 15 onto the rosette 6. The spherical form of the anchor body 21, rounded off on all sides, facilitates this application. If the cable 19 is pulled in the direction of the arrow 23, then an axial compression force is exerted on the tensioning element 15 by way of the anchor body 21, whereby the tensioning element suffers deformation in the transverse sense. Thus the profiles 24 arranged on the outer periphery of the tensioning element 15 in the upper, free region thereof, first come into engagement with the coils of the interior threading 25 of the plug 4. As a result, the cable force acting in the direction of the arrow 23 is also at least partly transmitted to the plug 4, which is thereby pressed against the rosette 6. At the same time, if the cable tension persists, the pressure of the profiles 24 in the thread coils 25 of the inner thread of the plug 4 rises. - 6 The exertion of an axial force on the plug 4 in the direction of tension of the cable 19 is achieved in that the socket 17 in the lower part of the plug 4 prevents an expansion of the tensioning element 15. The elastic separating groove 18 permits removal of the fresh sleeper body from the mould, without loosening the plug 4 in the fresh concrete. This is of particular significance, since the plug 4 often has to be concreted in at an angle to the vertical direction of removal of the shuttering.

The actuation of the cables 19 of the Individual securing devices 3 is preferably consolidated, as has been schematically indicated in Figures 1 and 2.

In this way, the cables 19 of the individual securing devices 3 are guided around guide rollers 26 and led to a lever 27, which is journalled in a bearing 28 on the base 2 of the shuttering. By turning the lever 27 in the direction of the arrow 29, tension is applied to the cables 19 as described above in connection with Figure 4.

In the turned position (Figure 2) for fixing the plugs 4, the lever 27 can be secured, e.g. by a fixing latch. A fixing latch of that type is necessary when the actuation of the lever for tensioning the plug along with the mould takes place only for a short time, and no actuating force operates on the lever during the concreting process. The lever then remains in the tensioned position, and thus the plugs remain tensioned with the shuttering mould until this tensioning is removed by releasing the fixing latch before removal from the mould. A closing latch and actuating means are not illustrated, in order to keep the drawings simple; the actuation of the lever 17 can take place manually, or also by means of hydraulic or compressed air-driven cylinder and piston units.

Figure 3 shows a longitudinal section through a sleeper 30 with moulded-in plugs 4 after removal from the mould and in the position of use.

Claims (12)

1. A device for securing a socket-like accessory to be built into a component on a part of a shuttering mould which moulds an outer surface in the manufacture of building components, the device having a tensioning element of elastic material, which can be splayed against the inner wall of the accessory by a transverse expansion produced as a result of axial pressure generated by » means of a tension member passing through the tensioning element in its longitudinal direction and fixedly anchorable at an end thereof, wherein the tensioning element is formed as a tube and comprises an extension for a securing tube for penetrating a wall of the shuttering mould, over which the accessory can be placed, the tube being securable to the wall.

2. A device according to Claim 1, wherein the tensioning element is insertable into an extension of the longitudinal bore of the securing tube, which extension forms an abutment.

3. A device according to Claim 1 or Claim 2, wherein an upper part of the securing tube is formed as a bush for surrounding the tensioning element over a part of its length, the bush being separated from the remainder of the securing tube by a junction portion,

4. A device according to any of Claims 1 to 3, wherein the tension member serving to produce the axial pressure is formed as a cable guided within the tensioning element and within the securing tube In the manner of a bowden cable.

5. A device according to any of Claims 1 to 4, wherein a ball-shaped anchoring body is provided at said end of the tension member.

6. A device according to any of Claims 1 to 5, wherein the tensioning element is provided with profilings on at least a part of its peripheral surface projecting from the securing tube.

7. A device according fo Claim 6, wherein said profilings are ribs.

8. A device according fo any preceding claim, wherein said accessory is a screw plug of plastics or the like. - 8

9. A device according to any preceding claim, wherein said component is a concrete sleeper.

10. Apparatus for manufacturing components from concrete comprising a shuttering mould and a plurality of devices according to Claim 4, wherein the 5 cables of the individual devices are led to a common actuating device.

11. A device for securing to shuttering a socket-like accessory for subsequent building into a concrete component, substantially as herein described with reference to and as illustrated in the accompanying drawings.

12. Apparatus for manufacturing components from concrete comprising a 10 shuttering mould and a plurality of securing devices, substantially as described herein with reference to and as shown in Figures 1 and 2 of the accompanying drawings.