Patent GB-191120229-A (GB)
Title: Improvements in Automatic Means for Balancing Aerial Machines.
Inventor: BENNI PAUL
IPC: B64C1/00
Filed: 1911-09-12
Granted: 1912-09-05
Abstract: 20,229. Benni, P. Sept. 12. Balancing.-Aerial machines are balanced by a system of masses acting by inertia to counteract the effect of changes of speed upon the machine, and by gravity to counteract changes in inclination, the movements of the system being transmitted to the controlling-planes by electric or compressed-air relays, or by suitable leverage. In the example shown, the system comprises a three-armed lever 19, 20, 21, which is pivoted at 7, and carries adjustable weights 24, 25, 26 arranged as shown, and two other pendulums 27, 28 which are pivoted to the horizontal arms and fitted with adjustable weights 29, 30. The pendulums 27, 28 are provided with electric contacts 31, 32 adapted to engage respectively with electric contacts 15, 16 and 17, 18, which are arranged in boxes 10, 13 and included in circuits containing a source of electricity E and electro-magnets 44, 45, which actuate a steering-member represented by an horizontal rudder 39, 40 pivoted at 41. The pendulums 27, 28 normally bear slightly against the outer walls 9, 14 of the boxes 10, 13. When the machine dips at the front end, the contact 32 of the pendulum 28, moving under the action of gravity, comes into engagement with the contact 18 and completes the circuit of the magnet 45, thus increasing the incidence of the elevator. Similarly, if the machine swings upwards at the front, the contacts 31, 15 engage, and actuate the magnet 44. When the speed of the machine is reduced, the pendulum 28 swings quickly forwards against the inner wall 12 of the box 13, and then descends more slowly on to the contact 17 due to oscillation of the system about the pivot 7, the latter movement being less rapid than that of the pendulum 28 about its pivot 20, since the weight 30 is arranged near the pivot 20, whereas the weights 24, 25 are disposed at a distance from the pivot 7. The engagement of the contacts 32, 17 then energizes the magnets 44, thus diminishing the incidence of the elevator so as to counteract the effect of the retardation of the machine. Similarly, when the speed of the machine is accelerated, the contacts 31, 16 engage, and energize the magnet 45. In order to ensure that the pendulums 27, 28 shall be moved into engagement with the contacts 16, 17 under the conditions last stated, even though they may be in engagement with the contacts 15, 18 when the change in speed occurs, subsidiary pendulums 33, 35 are mounted on a common pivot 8, the pendulum 33 having a weight 34 disposed so that its period of oscillation is shorter than that of the pendulum 35. These pendulums are fitted with contacts 36, 37, 38 arranged in circuits containing magnets 5, 6, adapted to actuate the horizontal arms 19, 20 of the main pendulum. Thus, when retardation in speed occurs, the contacts 36, 37 engage momentarily and energize the magnet 6, which jerks up the pendulum 28 clear of the contact 18 and allows it to swing forwards into engagement with contact 17. The contacts 37, 38 and magnet 5 act similarly upon the pendulum 27 when increase of speed occurs. The pendulum 33 may be damped by friction at its pivot or by immersion in oil. A similar device may be used for lateral balance. The weights may be arranged to roll on guide-bars, instead of swing- ing as pendulums.