Patent GB-867419-A (GB)
Title: Improvements in or relating to parachute coupling devices
IPC: B64D17/38
Filed: 1957-09-16
Abstract: 867,419. Parachute coupling devices. AUTOPLUG GERHARD SEDLMAYR G.m.b.H. Sept. 16, 1957 [Sept. 17, 1956], No. 29124/57. Class 4. A parachute coupling device comprises two telescopically engageable and releasable parts, for connection one to the parachute and one to the load, the outer part incorporating two relatively movable components, and means for automatically releasing said parts when the pull there between diminishes to a predetermined extent, wherein relative movement between one of said components and the inner coupling part is necessary before the automatic release means becomes operable, and deforrnable or rupturable blocking means is provided for normally preventing such relative movement, the blocking means being deformed or ruptured by the separating force applied to the coupling parts by the shock load of an opening parachute. In Fig. 1, a housing 20 having an enlarged centre 22 affording a chamber 43, receives a shear pin 45 passing also through a bolt 30 having a lug 32 for attachment to a load. A member 24 has a lug 33 for attachment to the parachute rigging lines, and has a head 36 formed with a seat 37 engaging six balls 40 (two shown), also seating on a seat 42 formed on the housing. A compression spring 44 acts between the balls and an end cap 26 on the housing. Prior to operation, the balls are held between seats 37 and 42 by abutment of head 36 and bolt 30, thus preventing member 24 from leaving the housing. On deployment of the canopy, the resulting shock shears pin 45, and bolt 30 moves down the distance x. The tension between load and canopy then holds the balls between the seats. On this tension dropping to a predetermined amount e.g. when the load contacts the ground, or when an aircraft equipped with a braking parachute slows to a predetermined speed, spring 44 displaces the balls 40 into chamber 43, and member 24 is free to leave the housing. In Fig. 6, a housing 50 and end cap 54 are secured by a pin 56 to which the load is attached. A member 53 with a lug 62 for attachment to the rigging lines enters the housing and has a head 65 with a seat 66. Six segments 61 (two shown) are normally held between seat 66 and a seat 60 on a piston 58 separated from the end plate 51 of the housing by a corrugated tube 62. The shock of deploying the canopy collapses the tube, so that the segments 61 are held between the seats only by the tension between the parachute and load. When this tension drops to a predetermined amount, a spring 59 displaces the segments and allows head 65 to move out of the housing. In Figs. 10 and 13, one member 70 is formed with two lugs 79 for attachment to the load, with two parallel plate parts 71 and 72 each having slots 82, and with a stem 91. Rollers 81 extend through the slots and each is mounted between a pair of links 80 pivoted at their lower ends to a bridge piece 91a slidable on stem 91. A stack of dished, spring plates 94 on stem 91 acts between bridge 91a and member 70. A member 76 has a lug 74 for attachment to the rigging lines, and has shoulders 77 normally retaining the rollers 80 in the vertical, innermost, parts of slots 82 by means of a shear pin 95 passing through plate 72 and member 76. The shock of deployment shears pin 95, whereafter the tension between members 70 and 76 maintains the rollers in the veritcal parts of slots 82, and abutting the shoulder 77. When the tension decreases to a predetermined amount, the spring plate 94 expand and links 80 pull the rollers into the lateral parts of slots 82, so that member 76 is free to disengage. In Figs. 15 and 17, part 101 comprises two parallel plates 102, 103 connected by a tubular member 104 having a bore 104a for connection to the load, and the other part 100 has a bore 107 for connection to the rigging lines, and is located between plates 102, 103, and connected thereto by a shear pin 120. A pin 111 passes through bores 112a in the plates 102, 103, and through a bore 113 in part 100, the pin and bore 113 having a mating step formation as at 112, Fig. 17. The pin is urged outwardly by a coil spring 133 acting in a cap 130 engaging the pin. The cap has safety chain 135. When the shear pin is in place, bore 107, pin 111, and bore 104a are out of line, so that the shock of deployment shears pin 120, and the tension between load and parachute holds bores 107 and 104a in line with pin 111. When this tension decreases to a predetermined amount, the coil spring 130 moves pin 111 out of bore 113, displacing member 100 by the wedge action of the mating formation 112. Part 100 is then free to leave part 101.