Patent GB-145890-A (GB)
Title: Improvements in control devices applicable to aircraft, marine steering-gear, and other apparatus
IPC: B64C13/24
Filed: 1919-04-04
Abstract: 145,890. Ruck, R. M., and Gardiner, W. C. April 4, 1919. Steering and balancing. A control device, applicable to aircraft, marine steering-gear, and other apparatus requiring the transmission of motion in either of two directions, comprises a reciprocating slide which is connected to the control surface or other load to be moved and is adapted to be operated by hand through mechanism which, when the resistance offered to hand actuation exceeds a predetermined amount, automatically brings into action a power relay, which continues the actuation of the control surface &c. but remains subject to the hand control. The invention is shown applied to a device for controlling the ailerons or elevator of an air-craft as described in Specification 146,548, in which a power relay is used comprising a cam-actuated ratchet mechanism, as described in Specification 112,480, [Class 80 (ii), Gearing, Variable-speed &c.], whereby the reciprocating slide is driven step by step and automatically locked at the completion of each step. Means may be provided for putting the relay mechanism out of action when it is desired to control by hand alone. The reciprocating slide 15, 16 is connected at 19, 20, Figs. 1 and 2, to the control surface, and carries the pivots 65 of bell-cranks, the arms 64 of which are attached to a member 63 movable longitudinally with, but laterally relatively tb, the slide, while the arms 66 of the bell-cranks are connected to a link 67 connected at 69, 70 to the hand control, the arrangement being such that when the hand control is actuated, the members 63 and 15, 16 and the bell-cranks move as a whole until the resistance offered to movement is sufficient to cause the bell-cranks to be oscillated so as to displace the member 63 laterally and bring the power relay into action. In a modification, the bell-cranks are replaced by inclined slots formed in the member 63 and engaging pins fixed to the slide 15, 16, springs being provided to retain the pins normally at the centres of the slots. The power relay comprises a continuously-driven shaft 11 formed with cams 31, 32 arranged to engage pawls 23, 24, Figs. 1, 5, and 6, keyed on shafts 25, 26 and adapted to engage notches 21, 22 formed in opposite edges of the slide 16. According to the direction of movement desired, one or other of the pawls 23, 24 is allowed to engage with the slide 16 and its corresponding cam 31 or 32, the rotation of which displaces the pawl along its shaft against the action of a spring 27 or 28, Fig. 5, thereby moving the slide 16 one step; at the end of the step, the pawl is raised by a cam 33 or 34, Figs. 1 and 3, out of engagement with the slide and returned by its spring 27 or 28 ready for the next step. The lateral movement of the member 63 brings the relay into action by moving one or other of levers 49, 50, Fig. 3, about its pivot 51 or 52, thereby disengaging a catch 47 or 48 and allowing the corresponding pawl 23 or 24 to fall into action. The slide is automatically locked at the end of each step by a pin 72, Fig. 1, adapted to engage a series of holes under the slide 16, but automatically released therefrom just before the commencement of the next step, by means of arms on the shafts 25, 26. The central hole of the series is omitted, so that the slide is not locked when in its central position, allowing the pilot to adjust the controls to the small extent required to maintain the equilibrium of the aircraft. Manually-actuated means may be provided for withdrawing the pin 72 at will. The two parts 15, 16 of the slide are normally locked together by a pin 84, which may be withdrawn by hand when it is desired to put the relay out of action, the upper part 15 of the slide then being moved by hand, while the part 16 remains stationary.