| 摘要 |
976,404. Adjustable seats. R. RAMILLON. Feb. 9, 1962 [Feb. 15, 1961], No. 5150/62. Heading A4J. [Also in Division E2] A hinge for interconnecting at least two lever arms comprises a first hinge part 3 having ratchet teeth 8 extending concentrically part way round the hinge axis 5, a spring-influenced pawl 14 pivotable on the second hinge part 2 about an axis 6 parallel to the axis 5 between a spring retained operative position, in which the pawl is arranged to engage the ratchet teeth and thereby permit only unidirectional stepwise angular displacement between the hinge parts, and a spring- retained inoperative position in which the pawl and ratchet teeth are disengaged, and cam means operable in response to relative angular displacement of the hinge parts to control the positioning of the pawl. The pawl has teeth 15 adapted to engage the ratchet teeth 8 and the cam means comprises a first cam 9 rigidly secured to the part 3 and provided with bosses 12, 13, and a second cam 18 rigidly secured to the pawl and provided with a boss 19. In the folded position the hinge parts lie parallel to one another and the pawl is held inoperative by the engagement of a spring 20 mounted on the part 2 with a recess 16 in the pawl. When it is desired to set the parts in a predetermined relative angular position the part 3 is first opened to its fullest extent so that the boss 13 abuts the boss 19, whereupon the cam 18 and pawl 14 are turned in the anti-clockwise direction to release the spring 20 from the recess 16. The part 3 is then brought back to the predetermined position in which it is locked by the pawl, which is biased into engagement with the ratchet teeth by the spring. When the part 3 is again folded the boss 12 abuts the boss 19 and returns the pawl to its inoperative position. Two parts 3 located in spaced parallel planes may be pivoted on separate pivots 5 on the part 2, two pawls being pivoted on the pin 6 to lock them. |
