GB722338A - Improvements in or relating to jet reaction means - Google Patents

Abstract

722,338. Jet-propulsion plant. ROLLSROYCE, Ltd. March 6, 1953 [March 10, 1952], No. 6225/52. Addition to 693,681. Class 110 (3). [Also in Groups XXVIII and XXXIII] Jet-propulsion means as claimed in the parent Specification has the sealing element in contact with the part-spherical surface formed by piston-ring type sealing means. The sheetmetal jet pipe 10 has secured to its end a T- sectioned strengthening ring 14, one web 14b of which supports an extension 15 of the jet pipe. A strengthening ring 17 is attached to the upstream end of the tail pipe 11. End rings 18, 19 are attached to the strengthening rings 14, 17. The end ring 18 comprises a bolting flange 18a and a portion 18b in the form of a zone of a sphere with its centre on the axis of the ring. The end ring 19 has a bolting flange 19a and a portion 19b in the form of zone of sphere with a beaded end 19c. The beaded end 19c is formed with a pair of axially-spaced circumferential grooves 20, the upstream walls of which are radial and the downstream walls of which are frusto-conical. 'These grooves are occupied by piston rings 21 which have external faces of part-spherical form to engage the internal surface of the portion 18b of the ring 18 and frustoconical faces to co-operate with the downstream walls of the grooves. These walls cause the gas pressure in the pipe to force the rings against the inner surface of the part 18b. The jet pipe 10 is supported from the vehicle structure 13 by a retractable spindle 23 which engages the hollow boss 25b of a bracket 25 bolted to the strengthening ring 14. The external surface of the boss 25b forms a bearing for a second bracket 26 attached to the strengthening ring 17 of the tail-pipe 11. The hollow boss 26a of the bracket 26 has a part-spherical bore which houses a collar 27 fitted on the external surface of the boss 25b. This arrangement allows rocking movement of the jet pipe 10 with respect to the vehicle structure 13 and of the tail pipe 11 with respect to the jet pipe 10 and vehicle structure 13. Modifications in which the part-spherical sealing surface is attached to the tail-pipe and in which the sealing rings are mounted in the outer member and co-operate with a part-spherical sealing surface on an inner member are described. A heat shield may be secured to the downstream end of the jet pipe 10 to extend axially over the ring 18. This shield is preferably formed in two arcuate parts.