Patent GB-448104-A (GB)
Title: Improvements in the braking of aircraft
IPC: B64C25/48
Filed: 1934-08-30
Abstract: 448,104. Aircraft brakes. BENDIX AVIATION CORPORATION, 105, West Adams Street, Chicago, U.S.A. Aug. 30, 1934, No. 25001. Convention date, Aug. 31, 1933. [Class 4] [See also Group XXXIV] An aeroplane brake system having brakes actuated by fluid pressure comprises a fluid pressure pump in permanent direct operative engagement with rudder control means, normally ineffective to actuate the brakes unequally, together with means, separate from the rudder control means, adapted both to actuate the brakes equally in co-operation with the pump and to render the pump operative for unequal application of the brakes. In the arrangement shown in Fig.1, a cable 349 connected to a handoperated lever moves pistons 339, 341 so that liquid is forced through pipes 242, 243 to take up slack in the brakes and an equalizing byepass connection 357 between the chambers at the back of pistons 278, 279 is closed. The operation of the rudder bar connection 227 moves piston 278 or 279 to force liquid through the pipes 242 or 243 to effect the braking of one or the other wheels. In a modification of Fig. 1, Fig. 4 (not shown), the pairs of pistons 278, 279 and 339, 341 are mounted in separate casings connected by pipes. In a modification, Fig. 2 (not shown), a cylinder casing for pistons corresponding to the pistons 278, 279 of Fig. 1, is movable on guide rails relative to the pistons to close the interconnecting passages by a manually-operated toggle. Fig. 3 shows an embodiment in which a manually-operated rod 749 is formed with a crosshead 747 engaging annular pistons 739, 741 slidable on pistons 678, 679 which are operable by the rudder connection 627 to produce differential braking when the pistons 739, 741 have been moved to the right to close the intercommmicating passage 757. In a further modification, Fig. 5, movement of the rudder bar 1027 is normally unrestricted by means of a passage 1181 through a valve 1183 connected to a member 1149 which moves piston 1141 in the cylinder 1169 and causes equal pressures to be applied by the liquid in the pipes 1042, 1043 leading to the passages 1179, 1187 with connections 1185, 1186 leading to the brakes ; at the same time, the rotation of the valve 1183 closes the byepass 1181 and subsequent movement of the rudder 1027 causes pressure to be applied differentially to the lines 1185, 1186 connected to the cylinders 1044, 1046. In a further modification, Fig. 6, a pipe 1365 corresponding to the pipe 1165, Fig. 5, is connected to a cylinder 1246 having a floating piston 1279 which moves to the right under fluid pressure when the hand-operated member 1349 for taking up slack is applied and liquid passes through the passage 1397 in valve 1383 to apply pressure equally to the brakes. A further piston 1278 which is moved in accordance with the movement of the rudder bar applies pressure through pipe 1242 or 1243 to the corresponding brake. In a further modification, Fig. 7 (not shown), pipes connected to the cylinders associated with the pistons controlled by the rudder bar are connected to the brakes and through a passage in a rotatable hand-operated valve member to fluid-pressure cylinders operating the rudder. When the valve is rotated the connection between the rudder-operating cylinders is interrupted and movement of the rudder bar controls solely the brake-operating cylinders. The Specification as open to inspection under Sect. 91 describes an arrangement, Fig. 2 (Cancelled), in which the rudder is controlled independently of actuation of the brakes by cables 22, 24 attached to members secured to concentric shafts 124, 125 operated by one member of each of the pairs of pedals 28, 32 and 26, 30 respectively. The braking action is controlled by one of the pairs of auxiliary pedals 50, 54 and 52, 56 of which the corresponding members effect through links the rotation of the shafts 116, 122. Links connected to the shafts 116, 122 effect the movements of rods 112, 118 which control valves 74, 75 associated with master cylinders 72, 73. The rod 112 controls a lever 108 which depresses a plunger 96, Fig. 4 (Cancelled), so that the con. nection between the chambers 74<b> and 74<a> of the valve 74 is broken. Further depression of a piston 102 resiliently connected to the plunger 96 causes a plunger 88 to open a valve 90 and connect a chamber 74<c> fed with compressed air to chamber 74b and thence through orifice 86 to the master cylinder 72, in which a piston 84 by means of a rod 82, moves a piston 78 to force liquid through a conduit 42 to the brake of one of the wheels. Movement of the rod 118 results in a similar operation in the cylinder 73 with corresponding braking of the associated wheel. Slack may be taken up by equal actuation of the pedals or by operation of a hand lever 48 which through links and an equalizing member 64 moves links 66, 68 coupled by a pin-and-slot connection to levers 70, 71 each formed with an annular piston engaging a sleeve 80 formed on the piston 78. This subject-matter does not appear in the Specification as accepted.