Patent GB-442014-A (GB)
Title: Improvements relating to aircraft
IPC: B64C27/02
Filed: 1934-07-27
Abstract: 442,014. Rotor starting - gear for gyroplanes. KAY GYROPLANES, Ltd., KAY, D., and DYER, J. W., 18, Atholl Crescent, Edinburgh. July 27, 1934, No. 22020. [Class 4] Mechanism for operatively connecting a power unit and the rotor of a gyroplane comprises a starter pinion connected to or integral with a spindle mounted on the rotor hub supporting member in such a manner that the axis of the spindle can be moved along a curved path toward or away from a position in which it is engaged by a gear wheel associated with the rotor hub, no matter whether the said supporting member is in its normal position inclined thereto, or moved bodily therefrom. Fig. 1 shows a rotor supporting member 1 tiltably mounted in the manner described in Specification 442,016. Spindle 17 of rotor starting pinion 18 is mounted in needle bearings in a housing 16 which is rotatably mounted in a casing 13 rigidly secured to member 2, the axis of the spindle 17 being offset with relation to the axis of rotation of housing 16. Turning movement of housing 16 is limited by stop means comprising flanges 62, 63, Fig. 2, formed on the inner housing and battlements 66, 67 formed on the outer casing 13. The eccentricity of the axis of pinion 18 is such that when driving crown wheel 28 secured to hub 1, Fig. 1, the reaction between engaging teeth will tend to force the teeth into deeper engagement, and, conversely, when rotor hub 1 over-runs pinion 18 the tendency will be for the teeth to be disengaged. The means for driving spindle 17 are as described in Specification 442,013 and comprise a universally jointed telescopic shaft connected to an output shaft of the aircraft engine by means including a manually operated friction clutch. Means for rotating housing 16 comprise a cable 31 fixed to bearing retaining plate 24, of housing 16, Fig. 1, by means of locking pin 25, the two ends of cable 31 being led to and passed in opposite directions around a control drum 32, Fig. 4, having an operating handle 33. Drum 32 is normally spring urged in the pinion releasing direction but when rotated to mesh pinion 18 with gear 28 for starting it is held by a spring-pressed pawl 34, Fig. 6, until such time as the pawl is manually tripped by lever 35 or automatically tripped by mechanism actuated by operation of blade-incidence control gear described in Specification 442,015 and comprising a slide 36 guided by the spindle of drum 32 and by a stud 52 mounted on a bracket supporting pawl 34 and connected by link 53 to a lever 54 connected to the incidence control gear. Slide 36 is formed with a shoulder 55 adapted to engage a trip 36A secured to the pivot of pawl 34. The starter control also effects engagement and disengagement of a dog clutch of which one element is arranged on the engine crank shaft and the other element on a slidable power take-off shaft adapted to drive the rotor starting pinion through the friction clutch referred to above. The dog clutch is engaged by a lever 38, Fig. 4, linked to one arm of a bell-crank lever 40 which is urged by spring 46 toward the clutch disengaged position. The other arm of lever 40 is provided with a guide through which passes a rod 42 upon which a coil spring 43 is arranged. Rod 42 is connected to a cable 37 wound on, and anchored to, drum 32. The arrangement is such that on the pilot turning drum 32 to engage the starter pinion, rod 42 is moved axially compressing spring 43 until the tension in the spring is sufficient to overcome that of spring 46 and cause engagement of the dog clutch. The dog-clutch is maintained in engagement, so long as the starter pinion is engaged, by means of pawl 34. Specification 442,137 also is referred to.