ARRANGEMENT FOR ATTACHING A FLANGE TO A WAVE GUIDE

Abstract: An arrangement is provided for attaching a flange (4) to a wave guide (1) and comprises a flange (4), a further flange (2) and a locking memeber (3) in the form of a frame or ring for respectively a rectangular or circular wave guide. The locking member (3) is placed between the flanges (2, 4). The flange (4) has a wall (46) of a recess (45) such that when both flanges are fastened the wave guide (1) and to each other, the locking member (3) penetrates a distance into the wave guide wall, thereby locking the flanges (2, 4) to the wall.

Description: TECHNICAL FIELD The present invention relates to an arrangement for attaching a first flange to a wave guide, the flange having first and second opposite surfaces being intended as a coupling member for coupling wave guides end-to-end and having an opening engaging the outer surface of the wave guide along its cross section, the arrangement including a second flange for fastening to said second surface of said first flange and having a cross section in relation to the cross section of the first flange such that in its fastened position it engages against the first flange, the opening of the first flange being provided with a recess open to the second surface, having a wall preferably extending all the way round the opening, the wall tapering a few degrees outwards in relation to the wave guide wall, with a locking member accommodated in said recess, so that the second flange urges the locking member into fixation against the wave guide wall. BACKGROUND ART Flanges attached to the wave guide ends are usually used in coupling two wave guides to each other. The wave guides are finally coupled together by connecting the flanges, using a bolted connection. A problem here is how the flange in its turn is to be fastened to the wave guide. FR-A 2237102 shows an arrangement in attaching a first flange to a tube by clamping the flange to the outer wall of the tube by means of a second flange that urges a locking member accommodated in a recess in the second flange into fixation against the wall of the tube when the second flange is tightened to the first flange. The first flange is provided with an opening through which the tube is extending. In coupling two tubes together the respective flanges are joined by bolts and an intermediate pipe sleave is inserted between the flanges over the projecting tube ends. DISCLOSURE OF INVENTION The present invention is based, as with the above-mentioned, known structure, on mechanically clamping the flange to the outer wall of the wave guide, and has the object of providing a secure and cheap attachment. The arrangement is characterized by the disclosures in the accompanying claims. According to the invention the wave guide is attached to the first flange in a manner similar to that of the known arrangement. However, by the opening in the flange being provided with a shoulder the wave guide does not project from the flange on the coupling side. Thus coupling two wave guides together can be attained by joining the respective flanges immediately together without the need of any intermediate member. At the same time the arrangement is such that when the second flange is tightened to the first flange the wave guide is urged against the shoulder of the opening, whereby a very secure attachment is achieved. BRIEF DESCRIPTION OF DRAWINGS The arrangement in accordance with the invention will now be described in more detail with reference to the accompanying drawing, where Figure 1 is an exploded cross section of the parts in the arrangement before assembling on a wave guide and Figure 2 is the same cross section with the parts in the arrangement in their finally assembled state on the wave guide. BEST MODE FOR CARRYING OUT THE INVENTION A wave guide with a rectangular or circular cross section and of a known kind is denoted by the numeral 1 in Figure 1. The proposed arrangement comprises three parts, namely a first flange 4, a second flange 2 and a locking member 3. The second, inward flange 2 is a compression flange and has an opening 21 of the same shape as the wave guide opening, e.g. rectangular, but of such dimensions that the flange 2 can be forced or eased onto the wave guide (see also Figure 2). The flange 2 further has two outer portions 22 and 23 with bored holes 22a and 23a. The first, outer flange 4, which constitutes the wave guide flange proper for coupling to an other wave guide, has two outer portions 41 and 42 with associated bored holes 41a and 42a as with the second flange 2. The first flange 4 has first and second opposite surfaces and has an rectangular opening 44, a second rectangular opening 43 and a recess 45 open to the second surface, all of different dimensions but with a common centre line coinciding with the centre line of the rectangular opening 21 in the second flange 2. The second opening 43 is the opening towards the unillustrated wave guide which is to be coupled to the wave guide 1. The opening 44 has corresponding dimensions to the opening 21 and shall engage against the outer wall of the wave guide. The recess 45 has somewhat larger dimensions than those of the opening 44 and is formed with a bevelled wall 46 which tapers some few degrees, e.g. 3°-5°, towards the centre line (the symmetrical axis of flanges 2 and 4). The third part of the arrangement in accordance with the invention is a locking member, in this case in the shape of a rectangular frame 3 placed between both flanges 2 and 4 according to Figure 1. The inner dimensions of the locking member 3 are suited to the outside dimensions of the wave guide 1, while its outside dimensions correspond to the recess 45. The wall thickness of the frame 3 is thus approximately as great as the width of the bottom 47 of the recess 45. Figure 2 illustrates the arrangement in its finally assembled state where the second flange 2, the locking member 3 and the first flange 4 have been pushed onto the end of the wave guide and where the first flange 4 has been fastened and pressed to the second flange 2 with the aid of unillustrated nuts and screws through the holes 22a, 41a and 23a, 42a. With the flanges 2 and 4 pressed together, the inmost part of the second flange 2 will engage against the upper engagement surface of the locking member 3, and since the width of the locking member is somewhat greater than the width of the bottom 47 of the recess 45, the lower inner edge part of the locking member will cut into the outer wall of the wave guide 1. With the meeting surfaces of both flanges 2 and 4 fully, mutually engaged as illustrated in the detail enlargement A, the locking member 3 is pressed a distance into the wave guide wall and the wave guide itself has been pressed against the shoulder 48 between the openings 43 and 44 of the flange 4 so that the outer edge surface of the wave guide engages against the shoulder 48. There is thus obtained a fixed and secure attachment of the first flange 4 to the wave guide 1. The locking member 3 does not need to be formed as a rectangular frame but can comprise such as two pins of the same thickness as the frame 3. These pins can then be situated one on either side of the wave guide.

Claims: 1. Arrangement for attaching a first flange (4) to a wave guide (1), the flange having first and second opposite surfaces being intended as a coupling member for coupling wave guides end-to-end and having an opening (44) engaging the outer surface of the wave guide along its cross section, the arrangement including a second flange (2) for fastening to said second surface of said first flange and having a cross section in relation to the cross section of the first flange (4) such that in its fastened position it engages against the first flange, the opening of the first flange being provided with a recess (45) open to the second surface, having a wall (46) preferably extending all the way round the opening, the wall (46) tapering a few degrees outwards in relation to the wave guide wall, with a locking member (3) accommodated in said recess, so that the second flange urges the locking member (3) into fixation against the wave guide wall (46), characterized in that the opening (44) of said first flange (4) is provided with a shoulder (48) defining a second opening (43) corresponding to the inner surface of the wave guide, and in that the wave guide is inserted in the opening (44) against the shoulder (48) of said first flange (4), and in that the locking member at the same time urges the wave guide against the shoulder (48) of the opening (44) of the first flange (4), when the second flange is tightened to the first flange.

Inventors: OLSSON, KURT GUNNAR
Applicants: TELEFONAKTIEBOLAGET L M ERICSSON
Application year: 1988
Main classification: H01P1
IPC codes: H01P11, H01P1