GB199909A - Improvements in or relating to parachutes - Google Patents

Abstract

199,909. V. L. Oil Processes, Ltd., (formerly V. M. L. Experimental, Ltd.), and Lucas, O. D. May 19, 1922. Parachutes. - Relates to parachutes provided with automatic means for reducing the resistance offered by the parachute when the airpressure becomes so great as to tend to injure the fabric. In a construction specially suitable for carrying pyrotechnic flares &c., the fabric is in the form of an endless band A, Fig. 1, having a depth approximately equal to one third of its diameter, the outer or lower edge of the band being connected by rigging ropes a' to a ring A<1> 'connected by cords a<1x> to the hook A<3> taking the load, and the upper or inner edge being connected by ropes a<2> to an elastic cord A<2>, the lower end of which is connected to the hoolc A<3> by ropes a<2x> passing through the ring A<1>. The length of the rope is such that in the normal sustaining condition the upper edge of the band A is drawn inwards to cause the fabric band to take the form of an annular ring as shown. When the resistance offered by the fabric band A becomes excessive, the spring A<2> stretches and permits the inner edge to rise, thereby automatically decreasing the sustaining power. The spring A<2> then re-acts to draw the inner edge downwards again to its normal sustaining position. In the modification shown in Fig. 3, the position of the inner edge may also be varied during descent by a handrope A<4> by means of which the spiral spring A may be contracted or permitted to stretch at will, the rope A<4> being fixed to the ring a<4> and passing over pulleys a<5x>, a<4x> attached to the lower and upper rings a<5>, a<4> respectively. If the maximum velocity is not too high the spring A<2> may be dispensed with by passing the cords a<2x>, Fig. 4, over pulleys a <6> connected to the load A<6>, and fastening them to the ring A<1>, stops a', a<8> being provided on the cords a<2x> for limiting their movement. The load A<6> resists upward movement of the inner edge of the band A until the air-pressure exceeds a predetermined limit, when the cords a<2x> run over the pulleys a<6> and permit the edge of the band to rise. A hand line may also be employed in this modification.