GB2126643A

GB2126643A - Moulded plastics component

Info

Publication number: GB2126643A
Application number: GB08226452A
Authority: GB
Inventors: Michael Joseph James
Original assignee: Micro & Precision Mouldings; Micro and Precision Mouldings Cheltenham Ltd
Current assignee: Micro & Precision Mouldings; Micro and Precision Mouldings Cheltenham Ltd
Priority date: 1982-09-16
Filing date: 1982-09-16
Publication date: 1984-03-28
Also published as: GB2126643B

Abstract

A moulded plastics component, designed as the housing for a magnetic door catch, is of rectangular box-like form and consists of a main part 1, moulded with screw-fixing flanges 5 and of a U-shaped cross- section defining a rectangular mouth 4 and a rectangular closure part 2 which is hingedly connected to the main part 1 through a thin moulded section 3 at one side edge of the mounting face. After moulding and to contain a magnet/pole-piece assembly of the catch the part 2 is hinged to a closure position in which it closes the mouth 4. To retain the parts 1 and 2, in the closed position, a strengthening rib along the free edge of the part 2 locates in recesses 9 at the ends of the mouth 4 and a fixing lip 10 snaps into a complementary recess within the part 1 at the edge of the mouth 4. <IMAGE>

Description

SPECIFICATION Moulded plastics components This invention relates to moulded components, and in particular to components which comprise a plastics moulding essentially moulded with an open-mouthed cross-section and which in the final component are required to have a closed hollow box-section providing structural strength.

Such components at present consist of an assembly of two separately formed parts, namely the moulding with the open-mouthed section and a closure part which is fixed across the open mouth of the moulding to complete the required box-section component. The closure part is typically also a plastics moulding, for example being in the form of closure plate. The fixing is normally achieved by means of adhesives or by welding along at least two opposite side edges of the moulding.

The object of the invention is to provide a component which can be produced as a single moulding, and which has other production advantages.

To this end, according to the invention, the component is moulded as a two-part moulding, comprising a main part with the open-mouthed cross-section and a closure part which is hingedly connected to the main part through a thin moulded section so that, after moulding, it can be hinged into the closure position to complete the closed box-section of the component.

In most instances the main part will be moulded with a generally U-shaped cross-section.

However, it will be appreciated that this part can be of any desired hollow cross-section presenting the open mouth of the section subsequently closed by the closure part, and it can have other features of shape such as may be desired or necessary to fulfill the intended function of the component.

The two parts may be formed so that they are a snap-together fit to complete the component, but they may alternatively (or additionally) be fixed by other means such as an adhesive or welding.

Substantially any flexible plastics material may be used for a component in accordance with the invention, a particularly suitable material being polypropylene. The two parts are conveniently secured together permanently by so-called implant welding, in which a piece of wire is positioned between the parts and heated to the plastics welding temperture by H. F. heating.

A wide range and diversity of components can be manufactured with advantage in accordance with the invention, which is of particularly valuable application to hollow box-like components. A typical example of such a component is the housing of a magnetic door catch, as used with cupboard and wardrobe doors, for example.

The invention will now be further described with reference to the accompanying drawings which illustrate, by way of example, a housing component in accordance with the invention. In the drawings: Figure 1 is a back view of the component in asmoulded condition; Figures 2 and 3 are respectively side and front views of the housing; Figure 4 is a cross-sectional view on the line lV-lV in Figure 2; and Figure 5 is an enlarged detail from Figure 4.

The component illustrated is the housing of a magnetic door catch of generally known form, being of closed generally rectangular box shape to house a conventional catch magnet/pole-piece assembly which is not illustrated. The component consists of a two-part moulding of a plastics material, for example polypropylene, with a main part 1 and a closure part 2. The parts 1 and 2 are hingedly interconnected through a thin moulded section 3. As shown more particularly in Figure 4, the main part 1 has a generally U-shaped lateral cross-section presenting an open mouth 4 at the back face of the moulding.

The closure part 2 is hinged to the part 1 along one side edge of said mouth 4 through the section 3. It provides in effect an integral closure plate for the part 1 and is moulded, as shown in Figure 1, lying generally in the plane of the back face of the part 1 which is moulded with end screw-fixing flanges 5 with inset screw holes 5a. One side wall 6 of the part 1, to which the part 2 is hinged, has four rectangular apertures such as 7 through which the pole pieces of the catch project in the normal manner.

Along its free edge the part 2 is moulded with a rectangular-section rib 8 which provides strengthening and in the final component the ends of this rib 8 fits into mating locating recesses 9 at the ends of the rectangular mouth 4. Over a central section of this edge the part 2 is also moulded with a fixing lip 10 which, as the part 2 is hinged to the cloure position within the mouth 4, snaps into position within a mating recess 11 moulded in the side wall 12 of the part 1. The fixing lip 10 is of truncated triangular crosssection, with an included angle of 450, and the edge of the side wall 12 is moulded with a 400 chamfer providing a ramp up which the lip 10 rides before it snaps into position within the mouth 4.

The part 1 has a spigot-like projection 13 which projects from a closed back wall 14 of that part within the housing, and a parallel shorter but otherwise similar projection 1 5 projects from the inner face of the part 2. These projections 13 and 15 engage the non-illustrated magnet/pole-piece assembly for location thereof within the housing.

As can be seen from Figures 2 and 3 the side walls 6 and 12 of the part 1 are extended at the ends to provide generally triangular reinforcing webs between which the screw holes 5a are inset.

It will be appreciated that the described construction provides a housing which also has considerable structural strength, due to the manner in which the closure part 2 snaps into position within the mouth 4 of the main part 1. In fact, adequate strength is provided without the trouble or expense of any additional fixing although, if desired, an adhesive may be introduced between the parts or implant welding employed at each or any of the side edges of the part 2.

Claims (Filed on 22 Aug 83) 1. A plastics component moulded as a twopart moulding of flexible material, comprising a main part with an open-mouthed cross-section and a closure part which is hingedly connected to the main part through a thin flexible moulded section so that, after moulding, the closure part can be hinged into a closure position across the mouth of the main part so that it completes a closed box-section of the component.

2. A plastics component according to claim 1, wherein said main part has a generally U-shaped moulded cross-section.

3. A plastics component according to claim 1 or claim 2, wherein said main and closure parts are formed so that they are a snap-together fit to complete the closed box-section of the component.

4. A plastics component according to claim 3, wherein said main and closure parts are alternatively (or additionally) fixed together with the closure part in said closure position by other means.

5. A plastics component according to claim 4, wherein said other means comprise an adhesive.

6. A plastics component according to claim 4, wherein said other means comprise welding.

7. A plastics component according to claim 6, wherein said main and closure parts are secured together permanently by so-called implant welding.

8. A plastics component according to any one of the preceding claims, wherein the flexible plastics moulding material is polypropylene.

9. A plastics component according to any one of the preceding claims wherein the component is a hollow box-like component.

10. A plastics component according to claim 9, wherein the component is the housing of a magnetic door catch such as is used with cupboard and wardrobe doors, for example.

11. A plastics component according to claim 10, wherein said main part is moulded with screw-fixing flanges, and the moulded mouth of the main part is positioned in a back mounting face of the housing between the flanges.

12. A plastics component according to claim 11, wherein said main part is moulded with side apertures adapted to receive pole pieces of a magnet/pole-piece assembly of the catch, and said main and closure parts are moulded with locating projections which are adapted to engage and locate that assembly within the housing.

13. A plastics component according to claim 1 1 or claim 12, wherein said closure part is of rectangular shape with the hinge line thereof disposed at one side edge of the housing, and this part when in said closure position substantially completely closes said mouth so as to complete the back mounting face of the housing.

14. A plastics component according to claim 1 3, wherein along its free edge remote from said hinge line said closure part is moulded with a strengthening rib the ends of which, in the closure position, fits into mating locating recesses at the ends of the mouth of said main part.

15. A plastics component according to claim 13 or claim 14, wherein along its free edge remote from said hinge line said closure part is moulded with a fixing lip which, as that part is hinged to the closure position, snaps into position within a complementary recess moulded in the corresponding side wall of said main part.

16. A plastics component according to claim 1 5, wherein said fixing lip is of truncated triangular cross-section and the edge of said main part engaged thereby is moulded with a chamfer providing a ramp up which the lip rides before it snaps into position within said complementary recess.

17. A magnetic door catch comprising a housing provided by a plastics component according to any one of claims 10 to 16.

18. A moulded plastics component substantially as herein particularly described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. trouble or expense of any additional fixing although, if desired, an adhesive may be introduced between the parts or implant welding employed at each or any of the side edges of the part 2. Claims (Filed on 22 Aug 83)

1. A plastics component moulded as a twopart moulding of flexible material, comprising a main part with an open-mouthed cross-section and a closure part which is hingedly connected to the main part through a thin flexible moulded section so that, after moulding, the closure part can be hinged into a closure position across the mouth of the main part so that it completes a closed box-section of the component.