AU638352B2 - A grommet - Google Patents

Description

1 638352 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A GROMMET 6* The following statement is a full description of this invention, including the best method of performing it known to the Applicant:- In various installations and apparatus, where an elongate member extends loosely through a hole in a web (which term is used herein to denote any panel or other machine or structural element made of sheet Smaterial), it is desirable to line the hole with a grommet to take up at 5 least some of the clearance between the web and the member and/or protect the member from abrasion and the like. For example, in the construction of steel framed buildings it is usual to run power and So communication cables, water pipes and the like through holes in the webs of the metal frame members, and, at least in better quality work, to line those holes with grommets.

The present invention provides improved grommets for use in such situations. It was devised with the last mentioned use in mind and is described below in that context; however it will be appreciated that grommets according to the invention may be used quite generally in other, analogous situations irrespective of the primary purpose of the web and the nature of the elongate member.

Some grommets are made of resilient or elastomeric material, in which instance the grommet is sometimes split to enable it to be positioned to encircle the elongate member other than by threading it upon the member from one end thereof. Split grommets are convenient, but are not as widely used as they might be, because of the risk of the elongate member being inadvertently forced into the split to make ~damaging contact with the web.

The present invention provides a split grommet which alleviates the above indicated deficiency in prior known grommets.

The invention consists in a split grommet comprising a body of resilient material having an outer surface adapted to receive the margin surrounding a hole in a web through which the grommet may extend and 0 an inner surface defining an opening through which a member may 6 extend, and a barrier tongue on the body disposed radially inwardly of the inner surface and extending beyond one end of the body so as to be overlapped, when in use, by the other end of the body.

S*

For preference the body may further comprise opposed spaced abutment means on the outer surface of the body adapted to receive between them said margin, and said abutment means may have a bight therein to facilitate bending of the body at the position of the bight.

3 In preferred embodiments of the invention, the tongue may extend integrally from one end of the body, the radially outer surface of the tongue may be an extension of the inner surface of the body, and at least one end of the body may be chamfered.

Preferably the inner surface of the body may have resilient support elements projecting therefrom, and those immediately adjacent the opposite sides of the gap may be offset.

Conveniently one edge of the body may be externally chamfered.

fe. By way of example an embodiment of the above described ."10 invention is described in more detail hereinafter with reference to the 0• accompanying drawings.

fee: 66 06 a.i•• 6 Figure 1 is a side elevation of a grommet according to the invention drawn to an enlarged scale.

Figure 2 is a sectional view taken on line 2-2 of figure 1.

l r• Figure 3 is a sectional view taken on line 3-3 of figure 1.

Figure 4 is a view similar to figure 2 showing the grommet in use in a web pierced by a pipe.

.a s The illustrated grommet may be a one piece moulding of nylon or other durable, yieldable but resilient material. It comprises a C-shaped body 5 of generally rectangular cross-section but for an external chamfer at one edge to facilitate the body's insertion, that edge first, through a hole in a web 6.

The body 5 has two opposed, spaced apart abutment means projecting radially from its outer surface. The first of those means comprises a circumferential flange 7 at the unchamfered edge of the body 5 adapted to contact one face of the web 6. The other of those means comprises three protrusions 8 spaced around the body 5 and adapted to contact the other face of the web 6.

A barrier tongue 9 extends from one end of the body 5 across the gap therein towards the other end of the body 5. The tongue 9 is formed integrally with the body 5. Its radially outer surface, except for an externally chamfered tip, is essentially an extension of the inner surface of the body 5. The other end of the body5 is internally o0 ~chamfered so that if the gap 10 between the ends of the body 5 is ot°" reduced by pressure applied to the body to bring its ends towards each V* 6, other, the tongue 9 slides readily under said other end of the body to close the gap 10 and provide the body 5 with an unbroken inner surface.

In the illustrated embodiment such ;'losure or partial closure of the gap 10 is facilitated by a bight 11 in the flange 7, more or less 0 diametrically opposite to the gap 10, which renders the body more easily 0 bendable at the position of the bight 11.

The illustrated embodiment is intended to surround a water pipe 12 extending through the web 6, and further comprises resilient so: support elements, for example, fins 13, to locate the pipe and hold it from direct bodily contact with the body 5. Those support elements mitigate the transfer of noise and shock from the pipe to the web in the event of water hammer occurring in the pipe. It will be noted (see figure 2) that the fins 13 to one side of the bight 11 are axially offset from the fins 13 on the other side of the bight 11. This is to ensure that the adjacent fins on each side of the bight 11 do not foul each other when the gap 10 is closed, and it is convenient in manufacture, having offset those adjacent fins, to maintain the offset for the remaining fins on each side of the bight 11.

The illustrated grommet may be deformed manually so as to widen the gap 10 to enable the grommet to be positioned about a pipe.

As a result of such positioning the fins 13 resiliently yield and adopt the disposition shown in figure 4. The grommet may then be squeezed by the fingers to close the gap 10, with the already inclined fins 13 further yielding to enable this to happen. While the gap is held closed the grommet may be slid along the pipe until the protrusions 8 pass through a clearance hole in the web 6. The finger pressure is then relaxed to allow the body to expand and engage the edge margin of the web surrounding the clearance hole, by trapping that margin between the ::15 protrusions 8 and the flange 7.

The grommet is preferably sized to suit the clearance hole in the web so that when positioned as described the gap 10 is partly closed.

This ensures that the grommet remains slightly elastically strained, and thus holds itself firmly in position, and further ensures that the tongue 9 20 extends fully across the gap 10 to be overlapped by the other end of the grommet' body.

.i In other embodiments of the invention, intended for use in conjunction with electric cables and the like, the fins 13 or their equivalent are not present.

Claims (9)

1. A split grommet comprising a body of resilient material having an outer surface adapted to receive the margin surrounding a hole in a web through which the grommet may extend and an inner surface defining an opening through which a member may extend, a barrier tongue on the body disposed radially inwardly of the inner surface and extending beyond one end of the body so as to be overlapped, when in use, by the other end of the body, and opposed spaced abutment means on the outer surface of the body adapted to receive the margin between them.

2. A grommet according to claim 1 further comprising resilient support elements projecting from the inner surface of the body.

3. A grommet according to claim 2 wherein at least the support elements immediately adjacent the opposite sides of the split are offset.

4. A grommet according to any one of the preceding claims 0: wherein one edge of the body is externally chamfered.

5. A grommet according to any one of the preceding claims wherein the tongue extends integrally from one end of the body.

6. A grommet according to any one of the preceding claims wherein the radially outer surface of the tongue is an extension of the inner surface of the body. :i

7. A grommet according to any one of the preceding claims ps wherein the tip of the tongue is externally chamfered.

8. A grommet according to any one of the preceding claims wherein there is a bight in the abutment means.

9. A grommet substantially as hereinbefore described with reference to the accompanying drawings. Applicant Attorney JOHN LYSAGHT (AUSTRALIA) LIMITED Date 28 August 1991 ROBERT G. SHELSTON F.I.P.A.A. of CARTER SMITH BEADLE S S S S S S* S S S. ABSTRACT A grommet is used to take up at least some of the clearance between a hole in a web and a member extending therethrough. Sometimes a grommet is split to enable it to be positioned to encircle the elongate member other than by threading it upon the member from one end. With split grommets there is a risk of the elongate member being inadvertently forced into the split to make damaging contact with the web. This is addressed by providing a split grommet comprising a C-shaped body of resilient material opposed, spaced apart abutment means 8) on the outer surface of said body adapted to receive between them the margin surrounding a hole in a web through which the grommet may extend, and a barrier tongue (9) disposed radially inwardly of the inner surface of said body and extending integrally from one end thereof across the gap (10) therein so as to be overlapped, when in use, by the other end of said body. i Figure 1 I so I*