Patent GB-905792-A (GB)
Abstract: 905,792. Releasable fastenings. AIRCRAFT MATERIALS Ltd., GOULD, G. H., and COWAN, S. S. April 21, 1960 [March 5, 1959], No. 7748/59. Class 44. A quickly releasable fastening device for a number of apertured harness components comprises a housing containing a number of spring- loaded fastening plungers adapted to be displaced independently by engagement with said components to permit said components to be attached thereto, an operating knob mounted on said housing and adapted to be rotated thereon between a release position in which it can be depressed to withdraw all the plungers together quickly to release the harness components and a safe and locking position in which the depression of the knob is prevented, and means for automatically retaining said knob rotated into said safe position until one or more of the harness components is attached to the device. The quick-release box for a parachute shown in Figs. 1 and 4 comprises a housing 10 mounting an operating knob 11, secured by a bolt and nut 13, 14, and a base-plate 15. A plunger 16, loaded upwardly by a spring 17 and flanged at 16a and having an inclined face 16b, is slidably mounted in each of four axial bores 12. The plungers 16, which normally project upwardly through radial slots 18, each of which is adapted to receive an apertured lug 19 of a harness strap, are each provided with diametrically-opposed flats 16c, the reduced parts being located in the slotted arms of a cruciform member 20 mounted centrally in the housing. The flats 16c prevent the plungers from rotating. The member 20 has four fixed sleeves 22 projecting through axial bores 21 in the housing. Each sleeve 22 slidably mounts a ball-headed pin 23 which is loaded by a spring 24 to project into the path of a lug 19 when this is inserted over a plunger 16. The lower ends of the pins project below the member 20 into keyhole slots 25 in a locking-plate 26 intended to prevent undesired withdrawal of the plungers. The shank of each pin 23 is capable of entering the narrow end of one of said slots 25 and is formed at its lower extremity with a head 27. The plate 26 is prevented from rotating by the pin heads 27 being seated in the wider ends of the slots 25. In this condition, plate recesses 26a register with the flanged ends of the plungers 16 so that the latter may be withdrawn. As the lugs 19 are successively inserted in the slots 18, the pins 23 are depressed in turn until the heads 27 leave the wider ends of the slots 25 thus enabling the plate 26 to be rotated into a position in which it prevents plunger withdrawal. Such plate rotation is effected by the engagement of an abutment 28 thereon by a pin 29 on a lever 30 pivoted in the housing 10 and loaded towards the abutment 28 by a spring 31. The plate 26 is subsequently disengaged from the flanges 16a by a pin 33 engaging the end of a cut-out 34 in the plate 26 on rotation of the operating knob to its release position. When the box is ready to receive the lugs 19, the plungers 16 and pins 23 extend into the slots 18 and the plate 26 is held free of the flanged ends of the plungers. When all the lugs have been inserted the rotation of the plate 26 causes it to overlap the flanged ends of the plungers. In order that the knob 11 is controlled by the insertion of a lug the slots 18 extend into a housing axial bore 40 slidably mounting a sleeve 41, the lower end of which has two diametrically-opposed dogs 42. The sleeve is loaded downwardly by a spring 39 and the dogs engage slots 43a in a flange 43 on the lower end of an operating member 44 which has a driving connection with the knob through a collar 45 engaging the top of the member 44 through pins 46. The sleeve 41 has an upwardly-flared flange 47 formed with a slot which accommodates a cam follower 52 in the housing so that rotation of the sleeve is prevented. With the dogs 42 in engagement with the slots 43a the knob 11 cannot be rotated. In this locked position the flange 47 projects into the slots 18 such that on insertion of a lug into one slot 18, the lug engages the flange, lifts the sleeve 41 and disengages the dogs, thus permitting rotation of the knob 11 into a release position. A radial bore 51 in the housing accommodates the cam follower 52 loaded by a spring 53 through an aperture 41a, in the flange 47 into a cam groove 54 formed in the member 44. This groove is divided transversely into upper and lower portions communicating at their respective ends. In the locked position of the knob 11 the follower 52 engages with one end of the lower portion of the groove 54 where it is in abutment with a step between the upper and lower groove portions which serves to prevent the depression of the member 44 and thus the knob. In the release position the follower 52 engages the other end of the groove lower portion from which it may be displaced into the upper portion over a step in the groove. This second step prevents the depressed member 44 from lifting whilst in this position. If, however, the knob 11 is turned back so that the follower 52 is transferred to the opposite end of the groove upper portion, the knob 11 and member 44 may be lifted back to the locked position. In operation, the lugs 19 are inserted with the knob in the locked position and until the dogs, and slots 42, 43a, are disengaged by the action of the lugs on the flange, the knob 11 cannot be turned to the release position. In practice, the box is worn with the strap lugs attached thereto and with the knob 11 in its locked position from which it may be turned to the release position and depressed to release the lugs simultaneously by depressing the member 20 and withdrawing the plungers 16 from the slots 18. The plungers 16 may be returned into the slots 18 by rotating the knob 11 in the opposite direction when it is lifted by the action of the springs 17 on the flanged ends of the plungers. Simultaneously plate 26 is rotated into the position of Fig. 1 by pin 33. In a further embodiment the box comprises a housing 60, Figs. 5, 6, 9, 11, 12, mounting an operating knob 61 retained by an axial bolt 63. Four axial bores 62 accommodate plungers 66 loaded by springs 67 and projecting upwardly through radial slots 68 each of which is adapted to receive an apertured lug of a harness strap. A locking-member in the form of a part-circular plate 71 is loosely attached to a member 72 by means of a guide bush 64 to allow limited rotary movement of the plate relative to the member 72. The plate has a bore 71a fitting loosely over the step 64a of the bush 64. The plate also has a recess 71b which accommodates a projection 64b on the step 64a. The bush 64 is clamped to the member 72 and has a driving connection to said member in the form of a pin 64c which engages in a recess in the member 72. The operating member has limited rotatory movement relative to the plate 71 but rotates said plate as soon as the projection 64b abuts the end of the recess 71b. The knob 61 is rotatably coupled to the member 72 through a key plate 73 having stepped pins 73a which project through holes 61c in the knob and engage in holes 72a in the member. Each plunger 66 has a flange 66c, reduced on one side 66d so as to fit within the wall of the housing 60 to prevent plunger rotation, and a peripheral groove 66c. The plate 71 is formed with cut-away portions 71c larger than the diameter of the plungers so that when the portions are in the position shown in Fig. 5, the plungers 66 can be displaced against the springs 67. The plate 71 is biased counterclockwise as seen from above in Fig. 5 by levers 74 pivotally mounted on bolts 75 and loaded by torsion-springs 76 so as to bear against the sides 71d of the plate 71. When the plungers are raised to their fastening position the plate 71, due to the spring-loaded levers 74, moves such that the edge of the plate at each cut-away portion enters the groove 66e in each plunger and locks it against displacement. To engage lugs over the plungers 66 by forcing the lug ends against the inclined plunger faces 66b, the knob 61 is turned slightly counterclockwise so as to cause the guide bush projection 64b to abut the plate recess 71b to rotate the plate out of engagement with the grooves in the plungers into the position shown in Fig. 5. When all the lugs have been engaged the knob is released and the levers 74 automatically cause the plate to move into locking engagement with all the plungers. The locking device for the knob 61 comprises a ring 77 rotatably mounted on a sleeve 78 which surrounds the member 72. The sleeve 78 is integral with a cover-plate 79. The ring 77 projects into the slots 68 and has four recesses each presenting a cam surface corresponding in shape with the end of a strap lug. The ring also has a radial slot 81 into which a part 60a of the housing projects, allowing the ring an angular movement of 10 degrees. The rotation of the member 72 in the ring 77 is controlled by a pin 82 slidably mounted in the ring. One end of the pin 82 bears on a camblock 83 secured in the housing whilst the other end engages a progressively deepening recess 72b in the member 72. In the locked position of the knob, Fig. 11, the pin 82 is wedged between the cam-block 83 and one end of the recess 72b, so that the member 72 and attached knob are prevented from rotating in a clockwise direction towards the unlocked position. When the member 72 is turned counterclockwise from the position of Fig. 11 the recess 72b therein is moved until the pin 82 abuts the deep end. Thereafter movement of the member 72 carries the pin 82 out of contact with the block 83 and into the position of Fig. 12 to thereby move the ring 77 into position for the insertion of the strap lugs. The ring 77 is spring-biased towards the position of Fig. 11, if, however, a lug is inserted into one of the slots 68 and over a plunger 66, the lug end engages a recess of the ring to thus hold it in the position of Fig. 12. This sli