| 摘要 |
1341579 Coiling spirals TENSATOR Ltd 12 May 1972 [25 Aug 1971] 39977/71 Heading B3E [Also in Division F2] A method of making a spiral spring comprises forming a strip of spring material so that one end is set to form a spiral coil while the remainder is straight or is set to coil spirally around the coiled end with a radius of curvature substantially greater than that of the coiled end, and then backwinding at least the coiled end. Fig. 1 shows a configuration before baokwinding, in which one quarter of the total length may be close or open coiled at 1. An attachment part 3 is then secured to an arbor and the spring is reverse wound about the arbor, so as to acquire a permanent set in the reverse sense corresponding to the unstressed configuration of Fig. 3. While still wound on the arbor, the spring is inserted into a casing to which end 4 is attached. The arbor may then be arranged to drive a seat belt reel, providing a rapid rise in torque during initial winding up, followed by a slower rise in torque. |
