GB2290774A

GB2290774A - Strip of grommets

Info

Publication number: GB2290774A
Application number: GB9511431A
Authority: GB
Inventors: Masaru Onodera
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 1994-06-22
Filing date: 1995-06-06
Publication date: 1996-01-10
Anticipated expiration: 2015-06-06
Also published as: GB9511431D0; GB2290774B; KR960001518A; SE9502242L; JPH084728A; SE9502242D0

Abstract

A grommet (1) having a body (2) and a flange (3) formed integrally with the body at one end thereof, and intended for attachment to an attachment panel formed with an attachment hole by disposing a packing between the flange and the attachment panel and inserting the body through the packing into the attachment hole, is linked with a plurality of like grommets (1) by insertion into a packing strip (11) constituted by a plurality of packings (12) which are formed with attachment holes for insertion of the grommet bodies (2) and are integrally connected by thin bands (13) between adjacent packings. <IMAGE>

Description

Grommet This invention relates to a grommet used for example to attach a vehicle trim panel or the like to an inner panel on the vehicle body side.

The passenger compartment of a vehicle is generally finished by attaching trim panels to inner panels on the vehicle body side. Since the trim panels are attached using tapping screws, grommets having tapping holes for screwing in the tapping screws have to be fitted into the inner panel before the tapping screws are used for the attachment. A large number of grommets are used at one time in this operation and each has to be individually picked up and fitted at a specific location. The work is therefore troublesome and also inefficient because the grommets are oriented in many different directions.

One method for overcoming this problem is to use grommets constituted as shown in Figure 7. In this method, a plurality of grommets 53 each formed of a body 51 and an integral flange 52 and having a tapping hole 59 at the center of the body 51 are manufactured in a strip by interconnecting the flanges 52 of adjacent grommets 53 with thin bands 54, and the grommets 53 are used either as strung together by the thin bands 54 or as broken apart at the thin bands 54.

More specifically, the grommets 53 are used for attaching a trim panel to an inner panel by first forming an attachment panel 55 (the inner panel on the vehicle body side) with attachment holes 56 for insertion of the bodies 51 of the grommets 53.

Then, for attaching a grommet 53 to the attachment panel 55, a packing 57 formed with a through hole 58 for passage of the grommet body 51 is positioned between flange 52 and the attachment panel 55, as shown in Figure 8, whereafter the body 51 of the grommet 53 is forced through the through hole 58 and into an attachment hole 56.

Next, a trim panel (not shown) is appropriately positioned relative to the attachment panel 55 and a tapping screw (not shown) is passed through the trim panel and screwed into the tapping hole 59 of each grommet 53 attached to the attachment panel 55 in the foregoing manner. When a tapping screw is screwed into a grommet 53, the body 51 of the grommet is expanded outward into pressure contact with the wall of the attachment hole 56 of the attachment panel 55. The grommets 53, and in turn the trim panel fixed thereto by the tapping screws, are thus attached to the inner panel.

With the prior art grommet structure shown in Figures 7 and 8, however, the packings 57 have to be disposed on the attachment panel 55 before the grommets 53 are attached. This lowers the efficiency of the attachment work.

An attempt to overcome this problem by fitting the packings 57 on the bodies 51 of the grommets 53 in advance runs into the problem that the packing 57 are apt to fall off the bodies 51 when the grommets 53 are oriented with the bodies 51 facing downward. This makes it difficult to automate the insertion process.

In addition, the spacing between adjacent grommets 53 (the length of the thin bands 54) cannot be easily changed owing to expense considerations. This is because a change in the spacing requires complete redesigning of the mold for producing the grommets 53, including the part for molding the complex grommet portions, and the cost for this is generally prohibitive.

The prior art grommet 53 used together with the packing 57 involves still another problem when the attachment hole 56 is formed within a recess 55a as shown in Figure 9. Namely, depending on the inner diameter of the recess 55a, the severed thin bands 54 may catch on the edges of the recess 55a, hindering smooth insertion into the attachment hole 56 and causing the grommet 53 to tilt to one side.

The present invention was accomplished in light of the foregoing problems and has as its object to provide a grommet improved in operability, amenable to automation, and relatively easy to redesign for changing the grommet spacing in a strip of the grommets.

The grommet according to the present invention comprises a body and a flange formed integrally with the body at one end thereof, the grommet being intended for attachment to an attachment panel formed with an attachment hole by disposing a packing between the flange and the attachment panel and inserting the body through the packing into the attachment hole, the grommet being characterized in that it is integrally linked with a plurality of like grommets by insertion into a packing strip constituted of a plurality of packings formed with attachment holes for insertion of the grommet bodies and connected by thin bands between adjacent packings.

For making the grommets easy to tear apart, the packing strip can be formed of a material whose properties are different from those of the grommets and that allows the thin bands connecting adjacent packings of the packing strip to be easily severed.

Owing to the constitution of the grommet according to the invention in the foregoing manner, a plurality of grommets can be handled together as a single unit by attaching them to the packings interconnected by the thin bands.

Further, since the grommets are attached to the packing strip from above, there is no danger of the grommets attached to the packing strip falling out before they can be inserted into the attachment panel. This facilitates automation.

In addition, the spacing between the grommets can be easily changed by changing only the design of the packing strip, which is of relatively simple configuration.

The invention will now be explained in detail with reference to the embodiment shown in the drawings.

Figure 1 is a perspective view, partially exploded, of grommets according to a first embodiment of the invention.

Figure 2 is a plan view showing a modification of the thin band connecting the grommets of Figure 1.

Figure 3 is a side view showing a modification of the thin band connecting the grommets of Figure 1.

Figure 4 is a perspective view showing how a grommet according to the invention is attached.

Figure 5 is a side view showing how a grommet according to the invention is attached.

Figure 6 is a sectional view showing another example of the attachment panel to which the grommet according to the invention is attached.

Figure 7 is a perspective view showing how a prior art grommet is attached.

Figure 8 is a side view showing how a prior art grommet is attached.

Figure 9 is a sectional view showing another example of the attachment panel to which the prior art grommet is attached.

An embodiment of the invention will now be explained in detail based on the drawings.

Figure 1 shows grommets 1 which are handled as a single unit together with a packing strip 11.

The grommets 1, which are made of resin, each consists of a body 2 of substantially rectangular cross section and a flange 3 formed integrally with the upper end of the body 2 and has a central tapping hole 4 extending from the flange 3 to the lower end of the body 2.

The packing strip 11 is made of resin and consists of a number of relatively thin, plate-like packings 12 strung together during the manufacturing process by thin bands 13. Each packing 12 is formed at its center with a vertical attachment hole 14 suitable for accommodating a body 2 of a grommet 1. For enhancing the packing performance of the packings 12, the packing strip 11 is preferably made of a softer resin material than that of the grommets 1. It may even be made of rubber, sponge or the like.

The thin bands 13 are designed so that they can be severed when necessary by exerting a strong pulling force between adjacent packings 12. The thin bands 13 of the embodiment shown in Figure 1 are of the same thickness as the packings 12 and of the same width throughout. For making them easier to sever, however, they can be formed with a narrow central portion 13a, as shown in Figure 2, or be formed thinner than the packings 12, as shown in Figure 3. If it is desired to reduce the breaking force required while also ensuring that the break occurs at a fixed portion of the thin band 13, this can be achieved by forming a V-shaped notch 13b at the center of the thin band 13 as indicated by the broken line in Figure 3.

Before being combined with the grommets 1, the packing strip 11 formed in this manner is stored as wound on a bobbin (not shown). Then when it is to be combined with the grommets 1, it is paid out from the bobbin and the body 2 of a grommet 1 is dropped and gently pushed from above into the attachment hole 14 of each packing 12 of the paid out portion. As a result, there is obtained a plurality of grommets 1 joined by a single packing strip 11. When used, the grommets 1 joined in this manner are broken off one by one or in groups of two or more.

Figures 4 and 5 show how the grommets 1 integrally joined in this manner are attached to an attachment panel 31.

This will be explained with reference to the case of using the grommets 1 for attaching a trim panel to an inner panel (attachment panel 31 on the vehicle body side) which is formed in advance with attachment holes 32 for insertion of the bodies 2 of the grommets 1.

As shown in Figure 5, each grommet is attached by grasping it with the fingers, for example, and pressing its body 2 into one of the attachment holes 32, thus simultaneous attaching both the grommet 1 and its packing 12.

Next, a trim panel (not shown) is appropriately positioned relative to the attachment panel 31 and a tapping screw (not shown) is passed through the trim panel and screwed into the tapping hole 4 of each grommet 1 attached to the attachment panel 31 in the foregoing manner. When a tapping screw is screwed into a grommet 1, the body 2 of the grommet is expanded outward into pressure contact with the wall of the attachment hole 32 of the attachment panel 31. The grommets 1, and in turn the trim panel fixed thereto by the tapping screws, are thus attached to the inner panel.

The grommet according to the foregoing embodiment enjoys improved handling property and operability owing to the fact that a plurality of the grommets 1 are inserted by their bodies 2 into the attachment holes 14 of the packings 12 of a packing strip 11 constituted of a plurality of the packings 12 strung together by interconnecting thin bands 13, whereby a plurality of the grommets 1 can be handled as single unit via the packing strip 11 and be separated for use in the required number by breaking off at one of the thin bands 13. Since the grommets 1 are attached to the packing strip 11 from above, moreover, there is no danger of the grommets 1 attached to the packing strip 11 falling out before they can be inserted into the attachment panel 31. This facilitates automation.

In addition, the spacing between the grommets can be easily changed by changing the design of the packing strip, which is of relatively simple configuration, without modifying the design of the grommet 1 itself.

When the attachment holes 32 are formed in smalldiameter recesses 31a, as shown in Figure 6, it is preferable to form the packing strip 11 of a material that is sufficiently softer than the resin used to form the grommets 1 because the greater compressibility this imparts to the packings 12 ensures that the thin bands 13 severed in the course of the insertion operation will be able to fit nicely into the recesses 31a without catching on the edges thereof.

As explained in the foregoing, the grommet according to the present invention enjoys operability owing to the fact that a plurality thereof are attached to packings strung together by thin bands and can thus be handled as a single unit.

Since the grommets are attached to the packing strip from above, moreover, there is no danger of the grommets attached to the packing strip falling out before they can be inserted into the attachment panel. This facilitates automation.

In addition, the spacing between the grommets can be easily changed by changing the design of only the packing strip, which is of relatively simple configuration, making it possible to implement design changes at low cost.

Claims

1. A grommet comprising a body and a flange formed integrally with the body at one end thereof, the grommet being intended for attachment to an attachment panel formed with an attachment hole by disposing a packing between the flange and the attachment panel and inserting the body through the packing into the attachment hole, and the grommet being linked with a plurality of like grommets by insertion into a packing strip constituted by a plurality of packings which are formed with attachment holes for insertion of the grommet bodies and are integrally connected by thin bands between adjacent packings.

2. A grommet according to claim 1, in which the grommet is made of a material having different properties from those of the packing strip.

3. A grommet according to claim 1 or claim 2, in which the thin bands between adjacent packings are thinned relatively to the adjacent packings.

4. A grommet substantially as hereinbefore described with reference to Figure 1 or Figure 1 as modified by either Figure 2 or Figure 3 of the accompanying drawings.