Patent GB-1485036-A (GB)
Title: Buckle for safety belts and harnesses
IPC: B60R22/32
Filed: 1974-09-20
Abstract: 1485036 Buckles SOC DITE ETUDES ET FABRICATIONS AERONAUTIQUES and G BARBE 20 Sept 1974 [21 Sept 1973] 41113/74 Heading E2A A buckle providing for manual and delayed automatic unfastening of a safety belt or parachute harness includes a casing 1, 2 accommodating a bolt 6 pivotally-mounted on a shaft 5 which also pivotally supports a bolt release lever 10 and which is carried by a frame 7 slidably mounted in the casing. The shaft extends through slots 4 in the sides of the casing and its ends are received in a yoke 9 acted on by a spring 8 serving to bias the frame 7 in the direction in which a shackle 60 is introduced into the casing for capture by the bolt. Introduction of the shackle compresses springs 23 to bias rockers 17, 18 on shaft 13 counter clockwise, but the shaft is initially prevented from responding to this bias by virtue of engagement of an axially-adjustable stop 14 on the shaft 13 with a pin 40 on a plate 37 movable laterally of frame 7 within limits defined by pins 38 and slots 39. A further, stop 12 on the shaft 13 engages the free end of lever 10, while the shaft is retained in its initial position, to prevent the lever responding to the bias of a spring 55. When the belt or harness applies a force to the shackle 60 sufficient to overcome the bias of spring 8, frame 7 shifts to the left and plate 37 is cammed in direction N against the bias of spring 45 due to the interaction of edge 41 of the plate with a pin 42 secured to the casing, the pin 40 consequently being moved clear of stop 14 so that shaft 13 is freed for rotation bysprings 23 at a rate determined by a mercuryfilled dashpot 27. When the shaft has been rotated sufficiently to move stop 12 clear of lever 10, and assuming that the force applied to the shackle has reduced sufficiently to allow spring 8 to return the frame 7 to its original position, lever 10 is moved by spring 55 and causes the bolt to disengage the shackle which is then ejected by springs 23. A leaf spring 16 cooperates with a third stop 15 on the shaft 13 to hold the latter in its final position until lever 10 is depressedby reset button 54, the lever having a lug 69 engageable with spring 16. If, in fact, the force applied by the shackle has not reduced sufficiently to allow spring 8 to return the frame 7 to its original position by the time stop 12 clears lever 10, then the bias applied by spring 55 is ineffective since the nose 56 of the bolt is held captive in an opening 57 in the casing. A further spring 24 is effective to return shaft 13 to its original position once the shackle has been ejected by springs 23. The bolt can also be actuated by a manually-operated slider 49, 50, and the delayed automatic release facility can be disabled by retracting pin 42 clear of plate 37. A cover 48 provided on the casing has a window 47 with which an indicator 46 aligns when the buckle is in the condition shown. Also disclosed is a twinbelt shackle with two slots and two lugs each disposed adjacent a respective one of the slots, each slot and its adjacent lug providing alternative facilities for securement of a respective belt to the shackle.