Patent GB-229667-A (GB)
Title: Automatic brake and acceleration regulating mechanism
IPC: B66D5/00
Filed: 1925-02-17
Abstract: 229,667. Fono, A. Feb. 21, 1924, [Convention date]. Automatic speed or power control.-Apparatus for maintaining a predetermined retardation or acceleration of a vehicle or lift, by adjustment of the braking or driving force is applied more particularly to the purpose of bringing a vehicle to rest within a given distance having regard to the speed at the moment. One form of the apparatus comprises a right-angled member 3, Fig. 1, the apex 2 of which is adjusted along a vertical guide by a centrifugal governor 1. One of the slotted arms of this member is engaged by a pin on a nut 5 which is moved by the travel or depth indicator in the application to a lift. The other slotted arm of the member 3 moves through a pin 6 sliding on a guide 7 a toothed quadrant 9 pivoted at 11. A second quadrant 10 also pivoted at 11 is controlled by an inertia governor connected at 8 in accordance with the actual retardation of the lift or vehicle at the moment. The distances 5x and 2x being thus proportional to the distance s within which the vehicle is to be brought to rest and to the speed v respectively the distance 6x and therefore the angular position of the sector 9 represents the value of the retardation p necessary to bring the vehicle to rest within the distance s. If the actual retardation p' is not equal to this predetermined retardation p a pinion 12 geared to the sectors 9, 10 moves a friction disc 15 splined on a shaft 16 with respect to a driving disc 14 whereby a pneumatic braking force regulator 20 is actuated by the shaft and an arm 19. The inertia governor may comprise a heavy wheel engaging a shaft by a quick-pitch screw thread, the shaft being driven from the vehicle &c. and being axially slidable against spring resistance. Another form of the apparatus comprises a dynamo 23, Fig. 3, the voltage of which is proportional to the speed, connected to a coil 24 and a resistance R proportional to the distance within which the vehicle is to be brought to rest. A second coil 25 and fixed resistance 26 are arranged in parallel with the coil 24 and resistance R. The coils 24, 25 are arranged in the manner of an output measuring device so that the torque exerted thereby is proportional to the product of the current passing through each of them. Since. the current through the coil 24 is proportional to v - where v is the speed and s the braking diss tance and the current through the coil 25 is proportional to the speed, the torque exerted by the v<2> two coils will be proportional to - that is to the s required value p of the retardation. The primary coil 27 of a transformer also connected across the terminals of the dynamo produces in the secondarv coil 28 and in a coil 29 a current which is proportional to the actual retardation p<1> experienced by the dynamo and therefore of the vehicle. The coil 29 is so arranged as to exert a torque in opposition to the torque exerted by the coils 24. 25 and thus the deflection of the instrument will indicate the difference between the actual retardation and that required. This deflection is used to vary the braking force acting on the vehicle. The Specification as open to inspection under Sect. 91 (3) (a) describes another form Figs. 4 (Cancelled), and 5 (Cancelled), in which a pump 30 driven by the vehicle circulates liquid through a chamber 31 provided with an orifice 46 the size of which is proportional to the distance s to be traversed by the vehicle. The velocity of the liquid is proportional to v the speed of the pump and of the vehicle so that a pressure difference v2 proportional to - that is to the required retardas tion p is established. This pressure difference is communicated by pipes 49, 50 to the pistons 53 of a compressed air regulator. This pressure difference is opposed by a pressure difference proportional to the actual retardation p<1> obtained by a device comprising a drum 32 driven by a pinion 38 at a speed proportional to the speed of the vehicle and provided with a radial partition 35 extending from an inner drum having a lateral partition 34. The spaces in front of and behind the partition 35 are connected by pipes 40, 41 to the chambers of the pistons 53 of the compressed air regulator. Fig. 2 (Cancelled) shows a further form in which masses m rotate about the point 21 and are guided on a track 22 to which a swinging mass M is coupled in such a manner that the centrifugal force on the masses m is balanced against the actual retarding force on the mass M. This subject-matter does not appear in the Specification as accepted.