WO2000010446A1

WO2000010446A1 - Scraper

Info

Publication number: WO2000010446A1
Application number: PCT/DK1999/000444
Authority: WO
Inventors: Poul Toft
Original assignee: Vikan A/S
Priority date: 1998-08-20
Filing date: 1999-08-20
Publication date: 2000-03-02
Also published as: NO20010562L; DK175909B1; FR2782626A3; AU5154399A; DK199801047A; EP1121045A1; NO20010562D0; FR2782626B3

Abstract

Scraper (1) for the cleaning of floors, windows, etc., comprising a scraper part (3) and a holder (2) produced from a plastic material, said holder (2) comprising a base plate (5), and that from the base plate (5) there extends a rail (4) of the same plastic material as the holder (2) and comprising oppositely-facing walls (6), said walls (6) joining in a concluding edge region (7), and in that the scraper part (3) is made of a plastic material which is based on the same plastic material as the holder (2), said scraper part (3) surrounding the free surfaces comprising walls (6) and concluding edge region (7) of the rail (4). There is hereby achieved a scraper without assembly joints of any kind, so that areas do not arise in which bacteria can collect and serve as breeding grounds for such bacteria.

Description

SCRAPER

The invention concerns a scraper for the cleaning of floors, windows etc., comprising a scraper part and a holder produced from a plastic material, said holder comprising a base plate.

Known scrapers comprise a scraper which is configured with a bent-over base plate, and in said base plate there is inserted a folded-together sponge of foam rubber which by friction thus fastens itself to the scraper head, which can also be further provided with a bead of some form or another around which the foam rubber sponge also grips.

Such a configuration gives rise to joints in which there is an extensive breeding ground for collections of bacteria, which is why such a scraper is not sufficiently hygienic for use within the foodstuffs sector, in which there are extraordinarily high hygienic requirements regarding the tools which are used in connection with cleaning.

It is the object of the present invention to provide a product which is not encumbered with the disadvantages of the known products, and where the scraper provided is without any form of assembly joints, so that areas do not arise in which bacteria can accumulate and serve as breeding grounds for such bacteria.

This object is achieved with a scraper of the kind disclosed in the introduction, and also where from the base plate there extends a rail of the same plastic material as the holder comprising oppositely-facing walls, said walls extending towards a concluding edge region, and in that the scraper part is made of a plastic material based on the same plastic material as the holder, said scraper part surrounding the free areas consisting of walls and concluding edge region of the rail.

In that the holder part of the scraper is produced of a plastic material moulded in one piece, and where on the centre part of the holder there is placed a rail of the same plastic material and preferably moulded in one piece with the holder part, there is achieved an area to which the actual scraper part can adhere. This scraper part is made of a plastic material of the same type, whereby during the production this will give rise to a fusing together with the rail due to the friction welding which will take place between the identical plastic materials. The result of such a welding together is thus that no areas can arise which can serve as breeding grounds for collections of bacteria.

By providing a scraper according to the invention as also disclosed in claim

2, an optimum configuration of the actual rail part is achieved, which optimises the adhesion of the scraper holder.

By providing a scraper according to the invention as disclosed in claim 3, it is achieved that the risk of bacterial collections is minimised.

By providing a scraper according to the invention as disclosed in claims 4 and 5, it is achieved that the base plate and the rail do not deflect during the production and thus give rise to a crooked scraper.

By providing a scraper according to the invention as disclosed in claim 6, it is achieved that the scraper part distributes itself evenly over the rail.

The invention also concerns a method for the production of a scraper such as this is disclosed in claim 7 to 9. The invention will now be explained in more detail with reference to the drawing, where

fig 1 shows a perspective view of the scraper comprising a holder and a rail, but not including the scraper part,

fig 2 shows the scraper in fig 1 seen from the one end,

fig 3 shows a scraper on which the scraper part has been welded, and

fig 4 shows a section along the line IV-IV in fig 3

In figs 1 and 3 there is shown an example embodiment of a scraper 1 according to the invention The scraper 1 comprises a holder 2 which is made of a plastic material, preferably polypropylene, and which comprises a flat base plate 5, and opposite this base plate a curved upper surface 12 on which a holder 9 for the shaft of the scraper 1 is mounted, preferably by the moulding of this in one piece with the rest of the scraper 1

Along the centre area of the base plate 5, which is of plane configuration, there is provided a rail 4 which extends out from the base plate, in that the centreline of said rail intersects the centreline of the base plate The rail follows the total length of the holder 2 and along its longitudinal axis Seen in cross-section, the rail 4 can be compared with an equal-sided trapezoid with slightly converging walls, said converging walls lying at 10-20°, preferably 8-12°, and which end in a concluding edge 7 which is preferably plane and parallel with the plane surface of the base plate Opposite the concluding edge 7, the rail is in connection with the holder 2 This connec- tion can possibly consist of gluing, but will typically be moulding in one piece together with the holder itself. The rail is made of the same plastic material as the holder. The rail and the holder have plane concluding areas 13 at each end.

Projections 8 extend from the walls of the rail, said projections being evenly distributed over the surface of each wall. The projections are cylindrical in shape with a height of ¹ -3 mm, and preferably ¹Λ-1 mm, and with a diameter of 4-8 mm. There will typically be five to ten projections distributed along each wall. The centre axes of the projections are substantially at right-angles to the walls. The object of these projections is to ensure that the holder with rail does not deflect during the moulding-on and welding of the actual scraper part 3, which will be dealt with in the following.

The further object of the projections is to provide a greater surface area to which the scraper part can adhere.

Fig. 2 shows the scraper without the scraper part and seen from the end of the scraper shown in fig. 1.

Fig. 3 shows a scraper 1 to which the scraper part 3 has been welded, while fig. 4 shows a section along the line IV-IV in fig. 3 transversely through the scraper. The scraper part is congruent with the rail 4, but where it continues past the concluding edge of the rail 4 it forms a flange 11 which has a certain flexibility and thus provides the scraper effect. The area of adherence between rail and scraper part ensures that the scraper part does not fall off, and that a secure connection is effected between the two elements. It is important here that the scraper part is made of a thermoplastic material based on the same plastic material as the holder and the rail, typically a thermoplastic polypropylene material. The thickness of the thermoplastic material which is in abutment against the wall is typically ¹/ -1 mm, and corresponding to the height of the projections 8.

The scraper part 3 surrounds the walls 4 of the rail, the concluding edge 7 and edge surfaces 13. Typically, the rail will end with a projecting edge of approx. AΛ mm in the area up against the base plate 5 in order for the thermoplastic material to fit tightly, and so that an edge is not formed for the collection of dirt. Alternatively, the thermoplastic material can end right up against the base surface.

Moreover, the plastic material of which the holder and the rail are made can with advantage be mixed with glass fibre, and in this way increase the stiffness of this part of the scraper 1. The connection of the scraper part 3 to the holder 2 and the rail 4 is effected by a friction welding, where this fric- tion welding takes place between the inner surfaces of the scraper part 3 against the walls of the rail 4 and the concluding edge 7 and surfaces 13 of the rail. The scraper part is also friction welded against the base surface. This welding together is made possible as a consequence of the materials being of the same type.

The actual production is effected by the holder 2 and the rail 4, projections 8 and the holder for the shaft 9 being moulded in one mould and typically in polypropylene. As mentioned, typically this polypropylene will often be mixed with glass fibre in order to increase the stiffness of the product. The stiffness is important when the scraper part is mounted or moulded on, so that the risk of deflection of the product is minimised, also during further processing. A hardness of 28-32 shore is selected, preferably 30 shore, so that the scraper is also effective over an uneven surface. When the holder 2 with rail 4 and projections 8 has been moulded, this product appearing as shown in fig. 1 , the product is placed in a new mould where a moulding-on of the actual scraper part 3 is effected. Under high pressure, typically around 800 bar, thermoplastic material based preferably on polypropylene is injected into the mould, and as a consequence of the projections 8, which are provided on the rail 4, it is ensured that this does not deflect under the high pressure and the subsequent influence of heat, in that the end surfaces 9 of the projections 8 lie up against the inner walls of the mould and thus maintain the position of the scraper. The material moulded on thus also surrounds the projections 8, with the exception of their end surfaces 9, which after the moulding-on of the scraper part stand exposed without any covering of thermoplastic material.

It is important here that the moulding-on takes place at a high speed, in that the assembly which takes place between the elements, i.e. the holder and rail on the one side and the scraper part on the other side, is effected by a friction welding. This friction welding is thus a function of the friction heat which occurs and not the mould temperatures which are used. Similarly, it is important that the basic material used for both scraper part and rail is the same in order for the fusing together to be possible.

The head itself, i.e. holder with rail and holder for the shaft, is typically moulded at a temperature of around 190°, while the actual rubber, the thermoplastic material which is injected into the mould to produce the scraper 3, is injected at a temperature of around 220-230°. However, the difference in temperature is not essential in order for the fusing together to take place, in that as mentioned this fusing together takes place as a consequence of friction welding. As mentioned above, it is important that the projections 8 are of such a size and such an extent that the position of the rail 4 is maintained in the mould during the injection of the thermoplastic material, which is ensured by the end surfaces of these projections 8 lying up against the inner surfaces of the mould. Typically, the dimension of the rail, measured from the base plate and at right-angles out from this to the concluding edge 7, is about 15-20 mm, while the breadth of the concluding edge 7 itself is typically 6-8, and the breadth of the area of the rail 4 adjoining the base surface lies at 12-14. The breadth of the base plate is typically 35-45 mm.

Materials suitable for the moulding of a scraper according to the invention are typically of the EPDM type.

Claims

1. Scraper (1) for the cleaning of floors, windows etc., comprising a scraper part (3) and a holder (2) produced from a plastic material, said holder (2) comprising a base plate (5), characterized in that from the base plate (5) there extends a rail (4) of the same plastic material as the holder (2) comprising oppositely-facing walls (6), said walls (6) extending towards a concluding edge region (7), and in that the scraper part (3) is made of a plastic material based on the same plastic material as the holder (2), said scraper part (3) surrounding the free areas consisting of walls (6) and concluding edge region (7) of the rail (4).

2. Scraper according to claim 1, characterized in that the walls (6) extend parallel with the longitudinal direction of the base plate (5) and con- verge towards the concluding edge region (7) at an angle of 10-30┬░.

3. Scraper according to any of the foregoing claims, characterized in that the holder (2) and the rail (4) are moulded together in one piece.

4. Scraper according to any of the foregoing claims, characterized in that projections (8) extend from the walls (6) and are distributed on both wall surfaces (6), and are of the same plastic material as the walls.

5. Scraper according to claim 4, characterized in that the end sur- faces of the projections (8) are exposed, and the remaining free areas are surrounded by the plastic material of the rail.

6. Scraper according to any of the foregoing claims, characterized in that the base plate (5) forms a plane surface with which the concluding edge region (7) extends in a substantially parallel manner.

7. Method for the production of a scraper according to any of the foregoing claims, c h a ra cte rized in that

the holder and the rail are moulded in the same plastic material in one mould,

the holder and the rail are subsequently placed in a new mould for the moulding-on of a scraper,

thermoplastic material under a given pressure is injected into the mould in the provision of the scraper, said material being based on the same plastic material as which the holder and the rail are produced, and

during the injection of the thermoplastic material, there are means which prevent the holder and rail from changing shape.

8. Method according to claim 7, c h a ra cte ri ze d in that the given pressure is 700-800 bar.

9. Method according to claim 7 or 8, c h a ra cte ri ze d in that the means comprise projections extending from the walls of the rail, said projections constituting an integral part of the rail, and that the projections are in contact with the surrounding walls of the mould during the moulding of the thermoplastic material.