GB2222216A - Means for mounting rings in bores of components - Google Patents

Abstract

A component (20) provided with locating means for snap-fitting or push-fitting a ring, circlip washer or the like in a bore in the component. The locating means comprise two series of abutments (26A, 28A) between which the ring, washer circlip or the like can locate. This obviates the need for an internal groove and, providing the two series are circumferentially staggered the component may be die cast. <IMAGE>

Description

BORES IN COMPONENTS This invention relates to bores in components.

Rings, such as washers and part rings, such as circlips (spring washers), hereinafter referred to as rings for the purposes of this specification, are often located in circular grooves in the bores of components such as pipe couplings and pipe connectors.

This is done by deforming the ring and by push-fitting or snap-fitting the ring into the groove. One such component is a plug ring for use in a flexible hose connector. Flexible hose connectors are used for connecting domestic gas cookers to the incoming mains supply and are the subject of British Standard 669 Part I 1984. One of the popular designs in general service uses a plug and socket connector. The plug ring forms part of the plug connector. A recommended design for the plug ring is shown in Figure 8(f) of BS.669 Part I (1984). In the accompanying drawings Figure 1 shows a plan view of this component and Figure 2 shows a cross section.

The plug ring is normally produced by turning and milling, and thus is an expensive component to manufacture in spite of it being manufactured by highly automated methods.

An alternative to turning and milling the component is to cast or form the component in a metal die. Die casting methods, are capable of producing components in large volumes at low cost and to close manufacturing tolerances. However, using die casting, particularly with small components, it is not possible to cast in situ internal circumferential grooves such as the continous circlip groove 8 in Figure 2, since it would not be possible ,due to the configuration of the die and the component, to remove the component from the mould without breaking either the component or the mould. The groove would have to be formed by a subsequent machining operation, thus adding to the cost.

Thus according to a first aspect of the present invention, there is provided a component having a bore and having a central axis through its bore, the component including; a first series of abutments circumferentially spaced about the bore of the component, and a second series of abutments circumferentially spaced around said bore and axially displaced from the first series of abutments, wherein the axial displacement is such that the two series of abutments are arranged to receive between them a ring , part ring, washer, circlip or the like and wherein the circumferential displacement of the respective series of abutments is such that none of the abutments in the first series directly face any substantial part of the abutments in the second series so that the bore of the component and the abutments are configured for die casting Components which used to need internal grooves for locating rings, washers, part rings and circlips can instead be designed to provide a series of axially and circumferentially displaced abutments to perform the same function as the grooves,with the advantage that the component can be die cast, or otherwise formed in a suitable mould.

The axial displacement between the two series of abutments defines the width of the locating means and the size of the displacement is varied depending on the width of the ring, part ring, washer, circlip or the like which is to be located in the bore of the component.

In a preferred embodiment the abutments are defined by a series of splines.

Each spline in the series may subtend the same angle to the central axis of the bore, with gaps between the splines also subtending the same angle.

According to a second aspect of the present invention there is provided a component in accordance with the first aspect of the present invention including a ring, part ring, washer, circlip or the like located between the two series of splines.

The component may be a plug ring for a plug and socket connector for connecting domestic gas cookers to the incoming mains supply. Preferably the component conforms to British Standard 669 Part 1, 1984.

The component may be die cast in a metal, such as a zinc alloy or an aluminium alloy. The component may also be formed by powder metallurgy.

Specific embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a plan view of an existing plug ring; Figure 2 is a cross section through the plug ring of figure 1; Figure 3 is a plan view of a plug ring embodying the present invention; and Figure 4 is a cross section through the plug ring of figure 3.

Referring to the drawings, figures 1 and 2 show an existing plug ring generally at 1. The plug ring comprises a first cylindrical portion 2, and a second coaxial cylindrical portion 4 of a smaller diameter than the first cylindrical portion 2. The outer curved surface of the first cylindrical portion 2 is knurled to provide a finger grip. The plug ring 1 provides a cylindrical internal bore 6 of substantially constant diameter,which is coaxial with the first and second cylindrical portions. A continuous groove 8 extends circumferentially around the inside of the bore.The groove is configured and suitably sized to receive a circlip (or spring washer) not shown. The circlip, which is usually in the form of an incomplete circle, is secured in the groove by temporarily distorting it and snap-fitting or push-fitting it into the groove.The second cylindrical portion 2 provides a pair of generally J shaped apertures 5 for locating the plug ring on a bayonet mounting.

The plug ring 1 was manufactured in brass by milling and turning.

Figures 3 and Figure 4 show, generally at 20, a plug ring configured for manufacture by die casting. The external shape and dimensions of the plug ring 20 are similar to those of the plug ring 1, having a first cylindrical portion 21 and a second coaxial cylindrical portion 22 of a smaller diameter than the first cylindrical portion. The ring also provides a pair of J shaped apertures 23 for mounting the plug ring 20 on a bayonet mounting. The outer curved surface of the first cylindrical portion 21 is scolloped, rather than knurled, to provide a finger grip.

The plug ring 20 has an approximately cylindrical interior bore 24 with a central axis 24A. In this interior bore there are two series of eight internal splines a first series of eight 26,and a second series of eight 28.

The first series of splines 26 is located in the smaller external diameter part 22. The second series of splines 28 is located in the larger diameter part 21 of the plug ring. The first series of splines comprises eight splines 26 each of which subtends an angle of 22.50 to the central axis 24A of the bore. The splines 26 are circumferentially displaced around the bore being separated by gaps or channels 27 each of which also subtends an angle of 22.50 to the central axis. Each spline 26 defines an abutment 26A, at an end of the spline which faces into the bore.

The second series of eight splines is circumferentially disposed around the bore in a similar manner to the first series. Each spline 28 subtends an angle of 22.50 to the central axis 24A and defines an abutment 28A on an end face. Each abutment 28A faces a channel 27 from the first series.

Channels 29, each of which subtends an angle of 22.50 to the central axis separate each spline 28.

Thus no abutment from either series of splines directly faces an abutment from the other series, hence the component may be diecast.

The abutments defined by the two series of splines do not meet but are axially displaced by an amount equivalent to the axial width of the circlip groove 1.

Thus the abutments defined by the two series of splines 26 and 27 define means which are suitable for locating a circlip and capable of carrying out the same function as the circlip groove 8 shown in in Figure 2, i.e. providing locating means into which z circlip or the like may snapfit.

As is stated above, this arrangement using two series of splines 26 and 28 instead of a groove 8 forms a suitable design for a metal die so that the plug ring 20 may be die cast.Thus it is possible to produce a metal component which functions and performs in a similar manner to the component shown in Figures 1 and 2 which can be produced as a die casting without any need for subsequent machining, and therefore at low cost.

The materials used in die casting are commonly zinc alloys and these materials in the die cast form have similar strength and other properties to those of brass.

The number and size- of the splines may vary. For example, two sets of four splines could be provided having a circumferential thickness of 450 could be used instead of 8 splines having a circumferential thickness of 22.50.

Clearly other components which have to receive circlips and the like in internal grooves can be redesigned with two series of abutments instead of internal grooves to allow such components to be die cast provided that the configuration of the component allows is suited to die casting.

Claims (9)

1. A component having a bore and having a central axis said bore, the component including ; a first series of abutments circumferentially spaced around the bore of the component, and a second series of abutments circumferentially spaced around said bore and axially spaced from the first series of abutments, wherein the axial displacement is such that the two series of abutments are arranged to receive between them a ring, part ring, washer, circlip or the like, and wherein the circumferential displacement of the respective series of abutments is such that none of the abutments in the first series directly face any substantial part of any of the abutments in the second series so that the bore of the component and the abutments are configured for die casting.

2. A component as claimed in claim 1 wherein the abutments are by defined splines.

3. A component as claimed in claim 2 wherein each spline subtends substantially the same angle to the central axis of the bore.

4. A component as claimed in claim 3 wherein there are channels between each spline and each channel subtends the same angle to the central axis of that bore.

5. A component as claimed in any preceeding claim wherein the component is a plug ring for a plug and socket connector.

6. A component as claimed in any preceeding claim wherein the component is a plug ring for a plug and socket connector for use in connecting domestic gas cookers to the mains gas supply and wherein the general configuration of the plug ring conforms to British Standard 669 Part 1,1984.

7. A component as claimed in any preceeding claim including a ring, part ring, washer, circlip or the like located between the two series of abutments.

8. A component substantially as hereinbefore described.

9. A plug ring substantially as hereinbefore described and with reference to figures 3 and 4 of the drawings.