GB2214594A - Spacer for box sections - Google Patents

Abstract

A post-assembled spacer tube A which bridges the cavity inside a closed structure D and directly reads fastener clamp loads, is expanded inside the cavity by inserting tappered collets B into the tube ends from outside the structure, and drawing them together by means of a clamp bolt C. The complete assembly facilitates a high performance through-bolt clamp joint such as a heavy fabricated towbar E bolted to the thin wall closed section underbody of a motor car. <IMAGE>

Description

SPACER FOR BOX SECTIONS This invention relates to a spacer for closed sections.

There are many applications that require bolted fixings to be evade through thin-walle4 closed sections. To enable bolted fixings to be tightened securely without collapsing the section, it is necessary to install a spacer within the section to resist the compressive loading of the fixing. This normally involves the difficulty of opening and re-closing the sect ion.

This invention is a spacer that can be inserted inside closed sections without the necessity of opening and re-closing the sect ion.

Figure 1. shows the arrangement of the spacer. together with a typical nut and bolt fastener. It consists of a tube fir which has a section that increases in diameter when the conical end bushes BP are pressed into its ends as the fastening C, is tightened.

Figure 2. shows typical sections for the tube.

fipplication: length of tube 7 is cut to suit the inside width of the section DS and as part of a loose assembly with the pre-assembled conical end bushes BS the component to be fixed E and a suitable bolt fastener C, is slid into the section via a clearance hole. See figure 3.

Rlternatively? flanged conical end bushes can be used, in this case only one bush is pre-assembled7 and the other conical end bush B, is slid over the bolt fastener and the nut C, is fitted. See figure 4.

The nut and bolt fastener C. is tightened, causing the conical end bushes BI to expand the diameter of the tube A, to form a spacer inside the the closed section Dw locally backing-up the thin wall and allowing the fastener to be further tightened to secure the component Et without collapsing the section. See figure 5.

NB: The flanged conical end bushes secure the assembly in line with the bolt hole if the bolt is removed for any reason.

Claims (8)

1 A spacer tube assembly comprising a tube and 2-tapered collets as shown in figure 1 of accompanying drawing.

2 A spacer tube assembly as claimed in CLAIM 1 wherein the tube may be of any number of various sections and including the sample split sections shown in figure 2 of accompanying drawing.

3 A spacer tube assembly as claimed in CLAIM 1 & 2 wherein the tube is assembled inside an enclosed structure cavity through a nominal clearance hole as shown in figure 3 of accompanying drawing.

4 A spacer tube assembly as claimed in CLAIM 1, 2 & 3 wherein the tube is expanded inside the cavity from outside the structure by the insertions of tapered collets at each end of the tube through the clearance hole as shown in figures 3 & 4 in the accompanying drawings.

5 A spacer tube assembly as claimed in CLAIM 4 wherein the collet may be plain as shown in figure 3 or flanged as shown in figure 4 of the accompanying drawing.

6 A spacer tube assembly as claimed in CLAIM 4 or 5 when assembled inside a cavity as shown in figure 5 of accompanying drawing will react bolt clamp loads without deformation of the thin structure walls.

7 A spacer tube assembly as claimed in CLAIM 5 & 6 wherein the clamp between the tube end and the structure wall is essentially over the complete tube end wall àrea.

8 A spacer tube asembly.as claimed in CLAIM 5, 6 & 7 wherein loads are effectively reacted directly between the thin walls and the attached component.