Patent GB-1039351-A (GB)
Title: Improvements in or relating to safety harness
Inventor: SPOUGE ERIC HERBERT
IPC: B60R22/36
Filed: 1961-11-15
Abstract: 1,039,351. Brake apparatus. TELEFLEX PRODUCTS Ltd. Nov. 14, 1962 [Nov. 15, 1961; July 27, 1962; Aug. 27, 1962], Nos. 40901/61, 28984/62 and 32809/62. Heading F2E. [Also in Division A3] A reel for a safety harness strap comprises a horizontally-mounted, spring-loaded spindle and a vehicle-acceleration-sensitive device mechanically coupled to the spindle for automatically locking it to prevent paying out of the strap. As shown in Fig. 1 accompanying Provisional Specification 28984/62, the vehicle-accelerationsensitive device comprises a gimbal-mounted pawl 33 including two pairs of arms 40, 42 and a weight 52. The pawl is associated with a conventional strap-acceleration-sensitive device including balls 26 movable, when an inertia plate 28 lags behind the spindle 15, along recesses 29 to force the plate against a friction plate 32. The inertia plate has circumferential teeth 54 with which any one of arms 40 or 42 can engage, depending on the direction of swing of weight 52. This engagement causes the plate 28 to lag and the above described braking action to take place. In a further embodiment, Fig. 5 (not shown), the weight 52 is replaced by a plunger 64 arranged in a housing 66 to be movable on tilting or sharp acceleration or deceleration of the vehicle to rock the pawl 33 and cause one of two arms 40 to engage the teeth 54. Figs. 6 and 7 show an optional additional hydraulic or pneumatic locking device which may be connected to e.g. the hydraulic brake system of the vehicle and Fig. 8 an electric locking device which may be connected in parallel with the brake warning light of the vehicle. In the simplest form of the invention, Fig. 3 (not shown), accompanying Provisional Specification 40901/61, the pawl 33 includes a single arm 35 which swings due to gravity e.g. when an aircraft dives or due to inertia when an aircraft sharply decelerates to contact the edge of the inertia plate and cause it to lag. The embodiment of Fig. 4 accompanying Provisional Specification 40901/61 includes opposed arms 35, 35a to cause locking of the reel also when an aircraft climbs, accelerates sharply or rolls over. In a further embodiment, Figs. 1 and 2 (not shown), accompanying the Complete Specification a strap-acceleration-sensitive device comprises a very light inertia member comprising a nut 28a mounted on a multi-start threaded portion of the spindle and teeth on the nut are engageable with teeth 96 on a brake plate 92. Associated with this device is a gimbal-mounted pawl 33 comprising arms 40, 40a normally located centrally within grooves 54a in peripheral teeth 54 on the nut 28a. Inertia forces, due to velocity changes in any direction will cause either arm 40 or 40a to engage one of the teeth 54, subsequent pull on the strap causing axial movement of the nut along the spindle to engage the teeth 96. Provisional Specification 32809/62 relates to a reel without a vehicle-acceleration-sensitive device in which the strap-acceleration-sensitive device, Figs. 1 and 3, not shown, includes an inertia member 6 with radial teeth 8 on an end face engageable with teeth 10 on a block 12. The sensitivity of the reel to locking action may be increased by means of a manually adjustable screw extending through the reel housing, Fig. 2 (not shown), and having a padded head which can be engaged with the inertia member. In an alternative construction, Figs. 3 and 4, a plane spring 40 carries a pad 62 which is engageable with the inertia member by means of a cable 52 secured to the end 46 of the spring and to a knob 76 associated with a control box 70. A pin 80 on the cable anchorage 74 engages a cam 78 on the box so that rotation of the knob pulls or releases the cable and thus moves the pad 62.