Patent GB-781515-A (GB)
Title: Improvements in or relating to release devices with manual and power actuation
IPC: B60P7/08
Filed: 1955-04-13
Abstract: 781,515. Latch fastenings. EASTERN ROTORCRAFT CORPORATION. April 13, 1955 [April 15, 1954]. No. 10674/54. Class 44 [Also in Groups XVII, XXXIII and XL(c)] A release device of the latch type which is releasable either under powered operation or manually comprises a latch member 56 pivoted to lugs 55 on a frame plate 54 said lugs having slots 58 through which the latch member pivot 57 extends to provide for translational movement of said latch member, power operated release mechanism including a piston and cylinder assembly 71, 75 supported on said frame plate, a part 64 connected to the piston 71 and engaging said latch member to normally hold it against pivotal motion, said par 64 being movable by the piston 71 to a position out of engagement with said latch member thereby permitting pivotal movement thereof, and channel means 77 leading to said cylinder. The latch member is adapted to engage a link 28 and it also has an arm 63 extending on the opposit side of the pivot 57 to the part which engages the link 28. The arm 63 enters a slot 68 in a block 65 which contains the cylinder 75 and the part 64 is a plate, a portion 69 of which crosses the slot 68 to prevent pivotal movement of the latch member. The piston is normally operated to the position in which the portion 69 releases the latch member by the pressure of gas supplied through the channel means 77. Manual operation of the latch member is effected by means of a handle 61 which is mounted on a pivot pin 62 carried by the lugs 55 and an extension 60 of which has slots 59 which engage the pivot 57 of the latch member. Since the pivot 57 is also mounted in the slots 58 when the handle 61 is moved to release the latch member the pivot 57 is moved along the slots 58 and carries the latch member with it. The arm 63 of the latch member remains in contact with the portion 69 of the plates 64 during this movement and so prevents the latch member tilting but' its movement along the slots 58 is sufficient to release the link 28. As shown in Fig. 5 the device may be used for connecting the ends of an aeroplane pilot's seat belt 44 when an ejector seat 42 is fitted to the aeroplane. In such case the gas pressure for powered release of the device is supplied by a unit 46 which is connected by a static line 45 to-the frame structure 47 of the aeroplane and this unit 46 is connected by a flexible tube 48 to the channel means 77 leading to the cylinder. The unit 46 includes an explosive shell fired by a timing device at the end of a preset interval after the static line 45 is pulled from the unit 46, which is done when the pilot ejects the seat from the aeroplane. Thus the ejection of the seat causes the release of the device by the application of gas pressure to the cylinder 75 so that the pilot is released from the seat after a preset interval. When the release device is used in this manner a connection is provided to a parachute release ring 50 so that the pilot's parachute is automatically opened as he is released from the seat. This connection consists of a static line 49 connected to a key 86. The key has a tapering head 87 and a groove 89 and the head fits in a corresponding opening in the end of a cylindrical plug 84. The plug is slidably mounted in a hole which is parallel with the cylinder 75 in the block 65. The hole extends through the block and also contains a detent 91, the plug 84 and detent 91 being urged in opposite directions by a spring 85. The key 86 is normally locked in position by the handle 61, an edge of a side plate of which engages in the groove 89 of the key. The groove is annular so that the key can be inserted in any position in the plug 84. To prevent inadvertent movement of the handle 61 the detent 91 engages a hole 92 in the opposite side plate of the handle. Thus when the release device is opened by using the handle 61 the key can be removed from the cylindrical plug 84 so that the pilot is released from the seat belt without opening the parachute but when the release device is operated by the unit 46 to release the link 28 the key remains attached to the plug 84 by the engagement of the edge of the handle with the groove in the key and as the pilot falls away from the seat the static line 49 pulls the parachute release ring 50. As shown in Fig. 2, the release device can also be used for securing the lid 25 of a container 20 containing a radio transmitter. The container is intended to be dropped from a lorry and when this happens a static line 22 connected to the lorry sets into operation a unit 24 identical with the unit 46 above which supplies gas pressure through a tube 26 to the cylinder 75, the link 28 which is on the container body is therefore released and the lid 25 opens under the pressure of a spring 30. A cable connection 31 connected to the key 86 of the device which is mounted on the lid then pulls a pin 32 from an aerial 33 and this withdrawal permits the aerial to extend from its container 34, a spring or compressed air mechanism causing the aerial extension Extension of the aerial in turn actuates an electric switch 35 which energizes the radio transmitter which is contained in a central box 36 in the container. The box 36 is supported inside the container by springs 37 and resilient insulating pads 38. If the device is manually released, the pin 33 is not pulled from the aerial since the key 86 becomes disconneced from the device.