Month in the Patent Office

Month in the Patent Office 732,127. Jet deflectors. Power Jets (Research and Development) Ltd. Application July 8, 1952. These abstracts of British Patent Specifications are condensed, by permission, from the official specifications. Copies of the full specifications are obtainable from the Patent Office, 25 Southampton Buildings, W.C.2, price 3s. each. 730,121. Reducing surface friction. Vivian Gray. the sides being welded to the reinforced portion along Application, May 15, 1953. the seams 14, 15. In the case of an aerofoil section, such as a propeller blade (FIG. 2e) the portions of the To reduce the surface friction of a body moving in sheet on cither side of the corrugations are bent to a fluid the skin is formed with regularly spaced cup- form the leading edge 19 and forward portion of shaped indentations 2 which, as shown, are of gener­ the undersurface, and the trailing edge portion 17, ally oval form, and arranged in staggered rows respectively, welding being carried out along the A jet deflector for a circular nozzle 1 which is 3, 4, 5, . . . spaced apart by approximately half the seams 21, 22 and also where the upper and lower skins divided into rearwardly and downwardly directed pitch of the indentations, such that at the desired bear against the angles 23, 24 of the reinforcement. portions \a, \b consists of a spherical shutter 3a, 3I> relative speed clastic waves set up in the fluid by the carried by side plates 3c and rotatable about a trans­ motion are reflected into and out of successive inden­ verse axis C, which passes through the intersection tations, whereby the fluid layer adjacent the surface is of the discharge nozzle axes, by a power unit 6 to maintained in oscillatory movement. The passage of close one of the nozzle outlets and open the other. the body sets up discontinuities in the layers of fluid If the nozzle is of rectangular section, the shutter 3a, adjacent to the skin to produce a wave-reflecting 3b is of cylindrical form. The nozzle outlets are pro­ surface 11 (FIG. 1b) so that a wave 10 set up by the vided with a number of parallel axially directed front 9 of the body is reflected successively by the vanes 2a, 2b. surface 11 and the indentations 2', 2", .. . as shown at 10, 10', 10" The staggered arrangement of the indentations ensures that adjacent layers of fluid do not interfere to any material extent. The resonant 732,292. Jet deflectors. S.N.E.C.M.A., France. vibrations set up over the whole body reduce the drag Application in France, April 22, 1952. by the action of the waves in breaking up the eddies which would otherwise be produced. In an arrangement for deflecting a propulsive jet by causing it to adhere to a curved surface forming a tangential-extension of the jet nozzle wall, provision is made to ensure that during normal operation the jet is separated from the curved surface to prevent its deflexion. According to one method, the portion of the curved surface at the region of tangency is rough­ ened, for example by filing or by the deposition of a coarse-grained metallic spray. In the arrangement 730,966. Control transmission systems. Bristol shown in FIG. 5a curved deflectors AB, A'B' are mov­ Aeroplane Co. Ltd. Application, April 7, 1952. able by a jack 6 from a normal (full line) non- In a control transmission having an end which is tangential position to a deflecting (dotted line) tan­ substantially free, so as to be subject to vibration gential position. In the further construction shown in relatively to a node in the system, instability is avoided by arranging that the stiffness of the system (defined as the reciprocal of the strain produced in an elementary unit length of the transmission member by unit load applied to one end of the system) varies along the system from the free end to the node approximately in proportion to the fourth power of the distance from a point at or somewhat beyond the free end. In the mechanical transmission linkage shown in FIG. 3a the hand lever 10 is manually re­ strained so that a node is produced at that end of the system, while the control surface is capable of vibra­ tion. The transmission consists of three rods 12, each adjacent pair being connected to a short lever 13 pivoted at its lower end 14 to the airframe, and to achieve the desired result the pivotal connexion 16 between each lever 13 and the rod 12 nearer the hand lever 10, i.e. the node, is farther from the pivot 14 than is the pivotal connexion 17 with the other rod. In the geared system shown in FIG. 3b adjacen t torque shafts 22 are connected by a small pinion 25 on the shaft nearer the hand lever 22 meshing with a larger pinion 26 on the farther shaft. At the output end the final shaft 22 is geared to the control surface 21 through eccentric pinions 27, 28 to give fine and coarse control at desired points in the range of movement of the hand lever. In a third arrangement the transmission is of the telemotor type, adjacent FIG. 5b rotatable members each formed with a semi- sections being separated by differential-diameter cylindrical surface a, c, b and a step e are movable pistons, the larger piston in each case being nearer from a position in which the step e is in line with the the hand lever. end of the nozzle (upper portion of figure) to one in which the semi-cylindrical surface is tangential to the nozzle (lower portion of figure). This arrangement may be modified so that the step e projects inside the nozzle in the normal working position. In other constructions the disengagement of the jet is obtained by causing a break in the continuity of the nozzle surface. Thus, as shown in FIG. 5C, the curved mem­ bers, A,B,A',B' are normally moved rearwardly into a position to open gaps between themselves and the 730,831. Sheet metal structures. E. Bruder and L. end of the nozzle, while in a modification the members Vayne. Application, May 11, 1953. A, B, A', B' are fixed and the openings are formed A structural member such as a reinforced box by axially-movable shutters. In the arrangement member is made from sheet metal by forming the shown in FIG. 5d a circumferential series of holes 42 central portion with reinforcing corrugations 3 is provided at the junction of the nozzle wall and (FIG. 2a), then bending the portions 4, 6 to form the curved deflecting members All so that normally the nozzle throat is open to the atmosphere to prevent lower and upper surfaces 5, 7 respectively (FIGS. 2b adhesion of the jet; to deflect the latter the holes 42 and 2c), and finally bending the edge portions of the are closed by an axially-movable ring 43. sheet to form the sides of the box section (FIG. 2d), http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Aircraft Engineering and Aerospace Technology Emerald Publishing

Month in the Patent Office

Aircraft Engineering and Aerospace Technology, Volume 27 (12): 1 – Dec 1, 1955

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Publisher
Emerald Publishing
Copyright
Copyright © Emerald Group Publishing Limited
ISSN
0002-2667
DOI
10.1108/eb032644
Publisher site
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Abstract

732,127. Jet deflectors. Power Jets (Research and Development) Ltd. Application July 8, 1952. These abstracts of British Patent Specifications are condensed, by permission, from the official specifications. Copies of the full specifications are obtainable from the Patent Office, 25 Southampton Buildings, W.C.2, price 3s. each. 730,121. Reducing surface friction. Vivian Gray. the sides being welded to the reinforced portion along Application, May 15, 1953. the seams 14, 15. In the case of an aerofoil section, such as a propeller blade (FIG. 2e) the portions of the To reduce the surface friction of a body moving in sheet on cither side of the corrugations are bent to a fluid the skin is formed with regularly spaced cup- form the leading edge 19 and forward portion of shaped indentations 2 which, as shown, are of gener­ the undersurface, and the trailing edge portion 17, ally oval form, and arranged in staggered rows respectively, welding being carried out along the A jet deflector for a circular nozzle 1 which is 3, 4, 5, . . . spaced apart by approximately half the seams 21, 22 and also where the upper and lower skins divided into rearwardly and downwardly directed pitch of the indentations, such that at the desired bear against the angles 23, 24 of the reinforcement. portions \a, \b consists of a spherical shutter 3a, 3I> relative speed clastic waves set up in the fluid by the carried by side plates 3c and rotatable about a trans­ motion are reflected into and out of successive inden­ verse axis C, which passes through the intersection tations, whereby the fluid layer adjacent the surface is of the discharge nozzle axes, by a power unit 6 to maintained in oscillatory movement. The passage of close one of the nozzle outlets and open the other. the body sets up discontinuities in the layers of fluid If the nozzle is of rectangular section, the shutter 3a, adjacent to the skin to produce a wave-reflecting 3b is of cylindrical form. The nozzle outlets are pro­ surface 11 (FIG. 1b) so that a wave 10 set up by the vided with a number of parallel axially directed front 9 of the body is reflected successively by the vanes 2a, 2b. surface 11 and the indentations 2', 2", .. . as shown at 10, 10', 10" The staggered arrangement of the indentations ensures that adjacent layers of fluid do not interfere to any material extent. The resonant 732,292. Jet deflectors. S.N.E.C.M.A., France. vibrations set up over the whole body reduce the drag Application in France, April 22, 1952. by the action of the waves in breaking up the eddies which would otherwise be produced. In an arrangement for deflecting a propulsive jet by causing it to adhere to a curved surface forming a tangential-extension of the jet nozzle wall, provision is made to ensure that during normal operation the jet is separated from the curved surface to prevent its deflexion. According to one method, the portion of the curved surface at the region of tangency is rough­ ened, for example by filing or by the deposition of a coarse-grained metallic spray. In the arrangement 730,966. Control transmission systems. Bristol shown in FIG. 5a curved deflectors AB, A'B' are mov­ Aeroplane Co. Ltd. Application, April 7, 1952. able by a jack 6 from a normal (full line) non- In a control transmission having an end which is tangential position to a deflecting (dotted line) tan­ substantially free, so as to be subject to vibration gential position. In the further construction shown in relatively to a node in the system, instability is avoided by arranging that the stiffness of the system (defined as the reciprocal of the strain produced in an elementary unit length of the transmission member by unit load applied to one end of the system) varies along the system from the free end to the node approximately in proportion to the fourth power of the distance from a point at or somewhat beyond the free end. In the mechanical transmission linkage shown in FIG. 3a the hand lever 10 is manually re­ strained so that a node is produced at that end of the system, while the control surface is capable of vibra­ tion. The transmission consists of three rods 12, each adjacent pair being connected to a short lever 13 pivoted at its lower end 14 to the airframe, and to achieve the desired result the pivotal connexion 16 between each lever 13 and the rod 12 nearer the hand lever 10, i.e. the node, is farther from the pivot 14 than is the pivotal connexion 17 with the other rod. In the geared system shown in FIG. 3b adjacen t torque shafts 22 are connected by a small pinion 25 on the shaft nearer the hand lever 22 meshing with a larger pinion 26 on the farther shaft. At the output end the final shaft 22 is geared to the control surface 21 through eccentric pinions 27, 28 to give fine and coarse control at desired points in the range of movement of the hand lever. In a third arrangement the transmission is of the telemotor type, adjacent FIG. 5b rotatable members each formed with a semi- sections being separated by differential-diameter cylindrical surface a, c, b and a step e are movable pistons, the larger piston in each case being nearer from a position in which the step e is in line with the the hand lever. end of the nozzle (upper portion of figure) to one in which the semi-cylindrical surface is tangential to the nozzle (lower portion of figure). This arrangement may be modified so that the step e projects inside the nozzle in the normal working position. In other constructions the disengagement of the jet is obtained by causing a break in the continuity of the nozzle surface. Thus, as shown in FIG. 5C, the curved mem­ bers, A,B,A',B' are normally moved rearwardly into a position to open gaps between themselves and the 730,831. Sheet metal structures. E. Bruder and L. end of the nozzle, while in a modification the members Vayne. Application, May 11, 1953. A, B, A', B' are fixed and the openings are formed A structural member such as a reinforced box by axially-movable shutters. In the arrangement member is made from sheet metal by forming the shown in FIG. 5d a circumferential series of holes 42 central portion with reinforcing corrugations 3 is provided at the junction of the nozzle wall and (FIG. 2a), then bending the portions 4, 6 to form the curved deflecting members All so that normally the nozzle throat is open to the atmosphere to prevent lower and upper surfaces 5, 7 respectively (FIGS. 2b adhesion of the jet; to deflect the latter the holes 42 and 2c), and finally bending the edge portions of the are closed by an axially-movable ring 43. sheet to form the sides of the box section (FIG. 2d),

Journal

Aircraft Engineering and Aerospace TechnologyEmerald Publishing

Published: Dec 1, 1955

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