Patent GB-610008-A (GB)
Title: Improvements in and relating to control systems for power driven movable objects
IPC: G05D3/14
Filed: 1942-09-24
Abstract: 610,008. Electric control systems. TUSTIN, A., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Sept. 24, 1942, No. 13470. [Class 40 (i)] A control system for a power-driven object comprises a control device having elements coupled to and, within limits, differentially responsive to displacements of a control member or handle and the object so.as to cause the application to the object of a torque dependent in magnitude on the relative displacement to reduce the displacement to zero, a slipping clutch being associated with the control device so that when the limits of relative displacement are exceeded, further operation of the control devices does not occur. The positions of the control member and object are, therefore, not necessarily maintained in correspondence but starting from any initial relative positions of rest correspondence is maintained over a limited range. The invention is described with reference to an electrical system but is not limited thereto. The control device comprises one member 14 carried by shaft 15 driven by step-down gearing 4, 30 from the control member 1, the other member 9 being carried by a sleeve 11 driven through a slipping clutch 34 and reduction gearing 5, 31 from shaft 6 coupled to the power-driven object. Member 14 carries a brush 18 connected over slip-ring 19 and brush 22 to an external terminal, whereas member 9 carries an arc of contacts 13 engaged by brush 18 and connected to resistances 24, 24a to provide the equivalent of tappings of a continuous resistance, the ends of which are taken to terminals over slip-rings 25, 26 and brushes 28, 29. Stops 35 limit the relative movement of the elements 9, 14 in both directions. In the circuit shown in Fig. 2, the tapped resistance 42, brush 18, variator winding 41 of metadyne 44 and the slip-ring gear are connected in a self-balancing bridge circuit with a centre tapped resistance 43 and source 40, driving motor 45 being controlled by the metadyne. Components of torque dependent on the velocities of the control member and object, and acting in opposition to each other, are introduced by tachometer 50, driven at 51, Fig. 1, by the control member, and by a tapping on resistance 53 across the motor armature, the resultant being applied to an auxiliary variator winding 52. The controller described in Specification 577,312, [Group XXXVII], may be used as the control device and the invention may be applied to the control systems described in Specifications 583,835, 583,836, 583,838, 583,839 and 609,204, a slipping clutch being used in place of the spring coupling. It may also be applied to the systems described in Specification 604,186 with the exception of one system, which already employs a slipping clutch. The clutch may be in positions other than that shown, and when the control device involves a differential gear, the clutch may be associated with either of the sun wheels or with the planet gear. The system introducing time derivatives described in Specification 609,804 may be employed with a slipping clutch and differential gear.