Split section body joints

Abstract: A means for and method of jointing together cylindrical bodies, in which one of the bodies is composed of two semi-cylindrical shells (2, 3). Each body is provided with a flanged end (4, 10) and (11) which are locked against one another by a threaded clamping ring (7) having a bevelled face (8). In an alternative embodiment, the clamping ring comprises a tapered circlip. The method is especially useful for the jointing together of the various cylindrical parts comprising a missile.

Description: This invention relates to means for and methods of jointing cylindrical bodies together where at least one body is longitudinally split. The invention is particularly useful for the jointing of cylindrical aerodynamic bodies, such as missiles for example. The missiles to which this invention is applicable are usually constructed by fitting two mating semi-cylindrical shells with necessary electronic control equipment and then clamping the mated shells onto a cylindrical body tube. The body tube may incorporate a propulsion unit. Known jointing methods involve the use of a series of fasteners or a manacle ring. These known fastener types have the disadvantage of making a marked contribution to the aerodynamic drag of the missile because they are not flush with the missile body skin. One known clamping arrangement which is disclosed in US-3,706,281 employs a circumferential band clamp whose ends overlap in order to clamp two shell halves, which comprise a missile fairing, to the missile body. Objects of this invention are to provide a clamping arrangement which does not incur an aerodynamic drag penalty, which eliminates the need for joint clearances and which provides good geometric alignment. According to a first aspect of this invention there is provided a tubular assembly comprising three separate parts joined together by a clamping ring, a first of said three separate parts being in the form of a cylinder, second and third of said three separate parts each comprising a respective section of a longitudinally-split cylinder, said first part having a first flanged portion at one end thereof, and characterised by said second and third parts having second bevelled flanged portions at one end thereof, said second portions being co-operable behind said first flanged portion so that said first, second and third parts form a tubular body, and said clamping ring having a bevelled face co-operable with the bevelled faces of said bevelled flanged portions of said second and third parts to hold said second portions against the rear face of said first flanged portion so that said first, second and third parts and said clamping ring co-operate to form said tubular assembly, wherein the tubular assembly has a substantially smoothly contoured exterior surface. According to a second aspect of the invention there is provided a method for jointing a tubular assembly comprising the steps of: providing a first part being in the form of a cylinder and having a first flanged portion at one end thereof, placing a clamping ring having a bevelled face over the first part and spaced from the first flanged portion; providing second and third parts each comprising a respective half of a longitudinally-split cylinder, said second and third parts each having second flanged portions with a bevelled face, fitting said second flanged portions behind said first flanged portion so that said first, second and third parts co-operate to form a tubular body, and moving said clamping ring toward said first flanged portion so that said bevelled face of the clamping ring abuts the bevelled faces of said second flanged portions and so that said second flanged portions are clamped against the rear face of the first flanged portion to form the tubular assembly, wherein the tubular assembly has a substantially smoothly contoured exterior surface. Using this arrangement with the clamping ring made flush with the outer skin of the three parts, no aerodynamic drag penalty is incurred. The bevelling of the ring and flanged portion of the second and third parts allows a component of the clamping forces exerted by the ring to be directed radially, i.e. inwards, towards the common longitudinal axis of the three parts, thus providing a rigid joint with good geometric alignment. The arrangement also eliminates the need for joint clearances because all tolerances in the jointed parts are eliminated by tightening the clamping ring. The arrangement has the further advantages of being uncomplicated and comprising very few parts. In one embodiment, the clamping ring is threaded and mates with a corresponding thread which is provided on the outer surface of the first part. In an alternative embodiment the clamping ring comprises a circlip. Preferably the first and second flanges are secured together by dowels and/or adhesive before the clamping ring is tightened up against the bevelled flanges. Embodiments of the invention will now be described by way of example only with reference to the drawings of which: Figure 1 is a perspective, exploded view of a joint in accordance with the invention; Figure 2 is a side view of the joint of Figure 1; Figure 3 is a cross-sectional view along the line A-A' in Figure 2; Figure 4 is a perspective, exploded view of an alternative form of joint in accordance with the invention; Figure 5 is a side view of the joint of Figure 4; Figure 6 is a cross-sectional view along the line B-B' of Figure 5; and Figure 7 is a sectional view of a third type of joint in accordance with the invention. A first embodiment will be described with reference to Figures 1, 2 and 3. The components to be joined together are a cylindrical body 1 and two split semi-cylindrical sections 2 and 3. These three components comprise part of a missile. The body 1 incorporates a flanged portion 4 at one of its ends a stepped portion 5 and an exterior screw thread 6 between flange 4 and stepped portion 5. A clamping ring 7 has a bevelled face 8 and its interior surface 9 is threaded. Each split semi-cylindrical section 2, 3 has a bevelled flanged end portion 10 and 11 respectively. In order to assemble the joint, the clamping ring 7 is threaded onto the cylindrical body 1 until it abuts the stepped portion 5. Then the two split sections 2 and 3 are offered up to the body 1 so that the flanged ends 10 and 11 interleave with the flanged portion 4. (See Fig. 3). The interleaving flanges 10, 11 and 4 are secured together with adhesive. Next, using a C-spanner the clamping ring 7 is tightened in a direction away from the stepped portion 5 and towards the flanges 10 and 11 until the bevelled face 8 of the ring 7 has clamped both bevelled flanges 10 and 11 against the flanged portion 4. The clamping ring thus provides lateral and axial compressive forces throughout the mating components 1, 2 and 3. A second alternative embodiment will now be described with reference to Figs. 4, 5 and 6. Components which are common to the first embodiment described with reference to Figs.1, 2 and 3 have been given the same reference numerals. The essential difference between the two methods is that in the second method, a tapered circlip 12 is employed in place of a threaded clamping ring. Thus, to assemble the components 1, 2 and 3 the circlip 12 is offered past the flanged portion 4 and the stepped portion 5 onto the full calibre of the cylindrical body 1. Then the two split sections 2 and 3 are mated to the body portion 1 as before and secured with dowels 13. Next, the circlip 12 is pulled back until it springs into the space between the flanges 10 and 11 and the stepped portion 5. The taper 14 on the circlip 12 abuts the bevelled part of the flanges 10 and 11 thus providing lateral and axial forces throughout the mating components. Fig. 7 shows how the method in accordance with the invention can be used to join body sections consisting of two split sections 14, 15, 16 and 17. Here an externally threaded central portion 18 has flanges 19, 20 at each of its ends which interleave with the bevelled flanged ends of the split sections 14, 15, 16 and 17. Two internally threaded clamping rings 21 and 22 with bevelled faces clamp the assembly together.

Claims: A tubular assembly comprising: three separate parts (1,2,3) joined together by a clamping ring (7), a first of said three separate parts being in the form of a cylinder (1), second and third of said three separate parts (2,3) each comprising a respective section of a longitudinally-split cylinder, said first part (1) having a first flanged portion (4) at one end thereof, and characterised by said second and third parts having second bevelled flanged portions (10,11) at one end thereof, said second portions (10,11) being cooperable behind said first flanged portion (4) so that said first, second and third parts form a tubular body, and said clamping ring (7) having a bevelled face (8) cooperable with the bevelled faces of said bevelled flanged portions (10,11) of said second and third parts (2,3) to hold said second portions (10,11) against the rear face of said first flanged portion (4) so that said first, second and third parts and said clamping ring (7) cooperate to form said tubular assembly, wherein the tubular assembly has a substantially smoothly contoured exterior surface. A tubular assembly as claimed in claim 1 wherein said first part (1) has an external screw thread and said clamping ring (7) has a corresponding internal screw thread, said clamping ring (7) being screwed toward the second bevelled flanged portions so that the bevelled face (8) of said clamping ring (7) is biased against the bevel of the second portions (10,11). A tubular assembly as claimed in claim 1 wherein said clamping ring comprises a circlip (12). A tubular assembly as claimed in any preceding claim wherein the first part (1) includes a propulsion unit. A method for jointing a tubular assembly comprising the steps of: providing a first part being in the form of a cylinder (1) and having a first flanged portion (4) at one end thereof, placing a clamping ring (7) having a bevelled face (8) over the first part (1) and spaced from the first flanged portion (4). providing second (2) and third (3) parts each comprising a respective half of a longitudinally-split cylinder, said second and third parts (2,3) each having second flanged portions (10,11) with a bevelled face, fitting said second flanged portions (10,11) behind said first flanged portion (4) so that said first, second and third parts cooperate to form a tubular body, and moving said clamping ring (7) toward said first flanged portion (4) so that said bevelled face (8) of the clamping ring (7) abuts the bevelled faces of said second flanged portions (10,11) and so that said second flanged portions are clamped against the rear face of the first flanged portion (4) to form the tubular assembly, wherein the tubular assembly has a substantially smoothly contoured exterior surface. The method as claimed in claim 5 wherein dowels (13) are provided for securing the first flanged portion (4) to the second flanged portions (10,11). The method as claimed in claim 5 wherein the first flanged portion (4) is secured to the second flanged portions (10,11) with an adhesive.

Inventors: GRAINGE RICHARD W BRITISH AERO, GRAINGE, RICHARD W., BRITISH AEROSPACE DEF. LTD.
Applicants: BRITISH AEROSPACE, BRITISH AEROSPACE PUBLIC LIMITED COMPANY
Application year: 1992
Main classification: F16B7
IPC codes: F16B7, F42B15