NZ196325A - Hard facing for tile forming equipment - Google Patents

Description

NEW ZEALAND PATENTS ACT, 1953 No.: Date: 23FEB1981 COMPLETE SPECIFICATION "APPARATUS FOR MANUFACTURING PROFILED TILES" X/Wc, KEDLAND ROOF TILES LIMITED, a British Company, of Redland House, Reigate, Surrey, RH2 OSJ, England hereby declare the invention for which £ / we pray that a patent may be granted to nas/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page la) - 1 at- 1 96 3 APPARATUS FOR MANUFACTURING PROFILED TILES The invention relates to apparatus for manufacturing profiled tiles, preferably roofing tiles, made of a -mouldable and hardening mass, preferably concrete, by 5 means of a rotating roller and, adjoining in the direction of production, a moulding and stationary slipper, under which the pallets filled with the mass are conveyed in the direction of production, whereby the moulded articles therein are compacted and shaped. 10 The aforementioned cooperating components of such apparatus were heretofore usually drop-forged or cast? however, when moulding a comparatively abrasive material, like concrete, especially when quartz sand is( used as an aggregate, they are exposed to a high degree of wear 15 which results in the fact that during operation of such a device the distance between these components, i.e. the distance between the edge of the slipper and the circumference of the roller, has to be adjusted repeatedly, in order to prevent deterioration of the 20 quality of the articles moulded by weans of these components. The manipulations required for these 19632 adjustments may cause uneconomical interruptions of operation and unnecessary sacrifices of time and manpower, as^well as a waste of material to be used. Apart from that, the durability of these carparativfely expensive ocrrpcnents is reduced because with increased wear the specified dimensions of the products can no longer be guaranteed; with increased wear in those areas, which are more strongly exposed to wear, the articles get increasingly thicker, so than an exchange of the components becomes necessary when a certain tolerance limit is exceeded.

The invention aims at solving this problem and increasing the durability of the aforementioned components. However, there are, first of all, certain difficulties insofar as, according to the present state of the art, it seems hardly possible simply to use steel of greater hardness for these components. Even if this were the case, the machining of such a material would be too costly and too difficult, due to the brittleness of the harder material. This brittleness would, in the present case, result in too high a scrap rate during manufacture and too great a danger of breaking during operation. However, the risk of breakage of a whole expensive component would, from the economic point of view, be too great also because of the interruption of operation resulting therefrom.

The invention provides apparatus for manufacturing profiled tiles of concrete qr a similar abrasive material / ? having a rotably mounted conjpaction roller and a fixed ~ 5 .15 196325 slipper under which moulds filled with concrete or similar material are conveyed and which give the profiled shape to the tiles, the fixed slipper following the roller in the direction of mould travel, the concrete or similar material in the moulds to be compacter and profiled by the roller and slipper, the compaction roller and/or slipper having on their surface areas which are subject to wear a facing of hardmetal (as herein defined) which facing is bonded to a base via an intermediate layer of a metal-plastic mixture which is capable of being poured and of hardening.

The slipper and/cr roller, which are subject to wear by the abrasive material, can have a solid supporting part made as usual of commercial quality steel, whereas their wearing surface is made cf a wear-resistant material of higher quality, which guarantees a considerably higher durability of these components. This higher quality material, although more brittle, can on the other hand, as a simple facing,be designed in such a way that it can be machined without any difficulty and put on the base, which is preferably of steel, of the components to be closely connected with this base.

However, another problem arises in this connection when putting on these facings insofar as the materials of the base on the one hand and the facing on the other hand have different physical properties and thus show also a different physical behaviour, in addition to a considerable i/SJ '! -- 1 963 25 brittleness of the material of the facing« In order to lessen, any difficulties and hazards resxxlting therefrom, for example due to any differences in temperature, the intermediate layer may consist of a metal-plastics mixture, preferably a steel-plastics mixture.

Such an intermediate layer with a high degree of adhesive strength and good elastic characteristics can compensate the different physical properties and the various changes of shape of the coating on the one hand and the base on the other hand, and still produce a reliable and cohesive assembly of these different materials.

The shape of the hard metal, facing can, in addition to this, be adapted to the base and connected therewith, for example by means of interlocking, undercut shaped tongues and grooves.

If difficulty is experienced in machining the hardmetal to the desired shape, the hard-metal facings of the roller and the slipper may, in accordance with their profiling, be divided in the.ir over-all widths and assembled in parts.

The invention is specifically,but not exclusively, intended for the manufacture of roofing tiles with several partly convex and partly planar areas extending over the over-all width, in particular for the manufacture of so-called Roman profiles.

The hardmetal facing of the slipper can, in accordance with the shape of the roofing tile to be manufactured which. h'a,s / extending over its width, partly convex and partly planar areas, be divided into just as many Planar and convex parts, which, with their longitudinal edges tightly joined, are connected with the base.

Likewise, the base of the roller can also, in accordance with the shape of the roofing tiles, be advantageously divided into parts, which are fixed to a . common driving shaft. This results in an additional advantage insofar as these parts can be exchanged or renewed separately in case of breakage without necessitating an exchange of the whole component. Therefore, separate parts of the base of the roller may be assigned to convex areas of the profiling, planar areas, and areas provided with grooves..

Preferably, only the areas which are excessively exposed to wear, i.e. only the plane areas of the roller and the edge area provided with grooves, have a coating made of hardmetal, which is fixed to the intermediate layer. Experience has shown that in the convex areas, which are generally less exposed to wear, no such coating is necessary. Therefore, the parts of the convex areas can consist completely of a softer hardmetal as compared with the hardmetal of the facings, the more so as solidly designed and comparatively small parts are involved which are less subject to the risk of breakage.

Apparatus embodying the invention will now be described, by way of example, with reference to the /r'\ /? 'wl .J ->. ^ 6 accompanying drawings, in which:- Figure 1 is a "diagrammatic general view of the already known basic arrangement of such apparatus; Figure 2 is a plan view in the direction of arrow 5 XI of Figure 1; Figure 3 is a front view in the direction of arrow III of Figure 1, in which, for the purpose of clarity, only the moulded article is shown in cross-section; Figures 4 and 5 are a cross-section and a longitudinal 10 section through the slipper, and Figure 6 is a longitudinal section through the roller. Figures 1 to 3 show a hopper 1, into which the concrete to be moulded is supplied from a mixer, the grain size of the aggregate being approximately 0 to 3 mm, and 15 from'where it is conveyed by means of a rotary distributor, for example a spike.shaft 2, which is to distribute the material equally under the so-called "roller" 3.

Pallets 5 mounted on a pallet track 4 (Figure 3) for moulding the articles 6 are conveyed to the bottom side 20 of this roller 3. By means of the roller 3 which rotates like the spike shaft 2 with a certain speed, the concrete filled from the hopper 1 into the pallets 5 is compacted and, at the same time, distributed correctly.

Now the pallets filled with the compacted concrete 25 pass under the slipper 7, which is positioned askew with a certain angle of inclination with reference to the pallet track 4 and which is with a pointed front side edge 1 96 3 facing the roller .juxtaposed to its bottom side. This so-called "slipper" 7 compacts, smoothes ax^d shapes the concrete in the passing pallets 5 into its final shape and is, by means of a pressure plate 8, adjustable with 5 reference to the roller 3, so that the size of the gap between these components can be adjusted. This gap had to be adjusted repeatedly at short intervals on the known apparatus of this kind due to constant wear of the components. The slipper 7 is supported by a frame 9 10 bridging the pallet track 4 and the conveying route of the pallets 5. The direction of production and the conveying direction of the pallets 5 are indicated by arrow 10.

The aforedescribed basic arrangement of the apparatus ■ represents the state of the art.

The slipper 7, shown on a larger scale in Figures 4 and 5 in longitudinal and cross-section, has a base 11, consisting of cast and forged stee'l, which is connected with a facing 13 made of the so-called hardmetal, by means of an intermediate bonding layer 12, consisting of a 20 mixture of approximately 80% steel and 20% epoxy resin, which is capable of being cast and hardened.

It is generally known that the term "hardmetal" stands for a cemented carbide product, which consists of one or several types of hard materials, for example 25 tungsten, titanium, tantalum carbide, etc. with a binder of the iron group, mostly cobalt but also nickel and iron, and which has a particularly high degree of hardness and resistance to wear. 1 96 3 The connection, between the b^se 11 and the facing 13 results already from the bonding by means of the intermediate layer 12; however, additional undercut shaped tongues 14 and grooves 15 can also be provided .to 5 secure this shape-adapted connection as shown in Figure 5.

Figure 4 shows tha/c the facing consists of parts, which conform to the planar' and convex areas of the slipper 7 and which, with their longitudinal edges tightly joined, are connected with the base 11.

The design of the roller 3 in accordance with the invention is shown in Figure 6, i.e. its base 16 consists of the parts 17, 17', 18 and 19, which are threaded on the driving shaft 20 and secured by means of a key 21 and a nut 22 to prevent relative rotation.

Also this roller 3 has, in accordance with the shaping of the moulded articles 6 to be manufactured, partly plane and partly convex shaped areas, i.e. the parts 17 and 17' are assigned to the convex areas, which are less exposed to wear, whereas the two parts 18 are assigned to the plane 20 areas, which are more exposed to wear, and the part 19 is assigned to the edge area of the roller 3, which forms the lateral grooves of the moulded article 6.

Because the small parts 17 and 17' are less exposed to wear, they can be made of a comparatively softer and more 25 easily machinable hardmetal and in one piece.

On the other hand, the identical parts 18 and the part 19 have each to be provided with a facing 23, * ;1 96 3 2 ;9 — ;consisting of a hardmetal of greater hardness, in order to be sufficiently wear-resistant. The facings 23 of the parts 18 and the coating 24 of the part 19 are connected with the base 16 and its: parts by means o.f an intermediate 5 layer 2 5 made of the aforementioned metal-plastics mixture suitable for this purpose. ;The intermediate layers 12 and 2 5 of the components of the device in accordance with the invention serve, as described previously, as a compensation for various 10 changes of shape of the different materials of which the components consist, and thus prevent the occurrence of endangering internal stress; simultaneously, they provide a reliable connection of the facings 13,23,24 to the bases 11 and 16 of these components-. The material for these 15 intermediate layers 12 and 25 can, before hardening, be poured between the bases and the coatings without any difficulty and then be hardened. ;It will be appreciated that the hardmetal facings of the above embodiment are shaped simply and sturdily, with 20 corresponding low-risk of breakage. ;The durability of the apparatus components, constructed in accordance with the invention, is considerably increased as compared with the similar components used heretofore consisting of forged and cast steel. While the prior 25 known components had to be exchanged after the production of approximately 225,000 units, because the wear was locally so considerable that the required dimensions of ;IO r. T, *7- V ^ v"' ^ «D' - HQ - the moulded articles .could no lonyej?. be .cjuaranteed, the components constructed in accordance with the invention showed, even after the production of more than five million units, still no wear worth mentioning, • 5 Another-major advantage of s-uch components lies in the fact that the adjustments of the slipper with reference to the roller which, up to now, had to be made on the known apparatus at short; intervals due to wear, are no longer necessary.

Due to the durability of the -moulding components, designed in accordance with, the invention, a constant high degree of quality and accuracy .in dimensions and weight of the moulded articles can be guaranteed.

Claims (11)

WHAT WE CLAIM IS:

1. Apparatus for manufacturing profiled tiles of concrete or a similar abrasive material having a rotatably mounted compaction roller and a fixed slipper under which moulds filled with concrete or similar material are conveyed and which give the profiled shape to the tiles, the fixed slipper following the roller in the direction of mould travel, the concrete or similar material 1n the moulds to be compacted and profiled by the roller and slipper, the compaction roller and/or slipper having on their surface areas which are subject to wear a facing of hardmetal (as herein defined) which facing is bonded to a base via an intermediate layer of a metal-plastic mixture which is capable of being poured and of hardening.

2. Apparatus as claimed in Claim 1 wherein the metal-plastic mixture is a steel-plastic mixture.

3. Apparatus as claimed in Claim 1 or 2 wherein the base consists of steel.

4. Apparatus as claimed in any preceding claim wherein the hardmetal facing and the base are formed with complementary interlocking undercut profiled tongues and grooves.

5. Apparatus as claimed in any preceding claim wherein the hardmetal facing of the compaction roller and/or of the slipper are divided over their width corresponding to their profiles and made up of individual parts. 196325 - 12 -

6. Apparatus as claimed in Claim t> tor the manufacture of shaped roofing tiles with several partly convex and partly planar areas extending over their width, wherein the facing of the slipper is divided accordingly into corresponding planar and convex parts having tightly joined edges and being connected with the base.

7. Apparatus as claimed 1n either Claim 3 or Claim 4 for the manufacture ot snapea roofing tiles with several partly convex and partly planar areas extending over their width, wherein the base of the roller is cylindrical and is divided into corresponding parts which are threaded on a common driving shaft and fixed thereto.

8. Apparatus as claimed in Claim 5 for the manufacture of roofing tiles having an edge area provided with grooves, the base of the roller having a separate part corresponding to the edge area provided with grooves.

9. Apparatus as claimed in Claim 6 wherein only the parts corresponding to the planar areas and the edge area provided with grooves, which are excessively exposed to wear, having a facing made of hardmetal, which is fixed to an intermediate layer.

10. Apparatus as claimed in Claim 7 wherein the parts corresponding to the convex areas consist of a softer hardmetal as compared with the hardmetal of the facings.

11. Apparatus for manufacturing profiled roofing tiles substantially as hereinbefore described with reference to and as shown 1n any of Figures 3 to 6 of the accompanying drawings. A. J. PER AGEtW . -