Patent GB-214215-A (GB)
Title: Improvements in automatic steering devices for dirigible craft
IPC: G05D1/02
Filed: 1924-03-18
Abstract: 214,215. Sperry Gyroscope Co., (Assign ees of Sperry, E. A.). April 9, 1923, [Convention date]. Automatic steering-gear.-Automatic steering devices for dirigible vessels are guided by a rudder and are controlled from a direction indioator are provided (1) with means for adjusting the relation between the deviation of the ship and the angular movement of the rudder for correcting this deviation; (2) with means for cutting out the control due to false yaw, that is, movements of the indicator resulting from combined pitching and rolling; (3) with means for giving a predetermined rudder overthrow; (4) with means for rapidly setting a new course; and (5) with means for cutting out the control when the rudder has been put over to a predetermined maximum angle. The control mechanism. The telemotor shaft 15, Fig. 2, may be operated directly by the hand wheel 10, or automatically by a motor 25 operating through gearing 26, 27, clutch 32, shaft 17, and chain gear 13, 14. For automatic control, a trolley 44, Fig. 5, with contacts 45, 46, Fig. 13, is controlled by the compass and is adapted to be moved over contact rings 41, 42. 43 which through switches 49 close circuits for energizing the motor 25. In its extreme position, the contacts close an alarm signal circuit 150. The contacts 45, 46 may be pivotally mounted on the ends of the trolley 44 and be held in engagement with the contact rings by a spring 161, Fig. 5. The trolley is rotated by the final gear 58 of a differential gear 57 from the compass repeater motor 50, Fig. 4, through a lost-motion device, whilst the follow-up gear operates the segments supporting disc 78 through gears 22, 61, 62, 63, an adjustable link 68, a collar 69, and gears 72 - - 76. The gears 57, 58 may be elliptical for varying the rates of deviation and rudder throw. Setting new course,. The trolley can be rotated, for setting a new course, by a hand wheel 80 which has a pin and slot connection 81, 82 with a shaft which is geared to a pinion 86 in the differential, and can therefore operate the final gear 57 of the trolley. When setting the course, the repeater motor is locked by a ratchet gear 90, the pawl 92 of which is moved into operation when the hand-wheel is slidden to make its pin connection. Adjusting rudder throw for a given angle of daviation is effected by varying the extent movement of the follow-up gear. For obtaining a variation, the pin 67, which passes through a slot in the lever 68, is carried by a plate 66 slidable in a bracket 65 on a shaft 64. On turning the control knob 105, the shaft 64 operates a starwheel and pin which moves the plate 66 as required. Eliminating false yaw control. An adjustable lost-motion connection between the repeater motor and the trolly is provided for this purpose. The trolley gear 58 is attached to a shaft 115 having thereon a wedge-shaped bar 121 which extends through wedge-shaped slots in a member 60 on the shaft 126 which carries the trollev. Relative axial movement of the shafts provides for variation in the lost motion between the bar 121 and slots. This movement is effected by an arm 130 carried by a nut 131 which can be moved by the screw 133 when the latter is rotated through the engagable pin and slot connection 135, 137 of the control knob 140. Providing for rudder overthrow. This is effected by delaying the operation of the followup gear. to which end a conical pin 70 on the collar 69 is made adjustable in relation to a conical opening in the gear 72 actuating the segments, such lost-motion adjustment being made by a sleeve and nut gear similar to that used for false yaw control. This adjustment is also used for taking up errors in the telemotor transmission. Limiting maximum rudder throw. This is accomplished by breaking the motor circuit by means of cams 166, 167, Fig. 8, on the shaft of and adjustably bolted to the gear 63. The cam engages pivoted levers 147, 148, Fig. 7, which in turn operate arms 160, 161 of the blades 154. 155 of the double-knife type switch which has two spring contacts 152. The blades are normally held closed by a spring 180. and levers 147, 148 have a spring 181. A double cam 185. when rotated so that the major axis AB is in line with the lugs 188, 189, holds the blades positively in the out position. When the minor axis CD is in line the switch is in but capable of being moved out by the cams. The motor circuit includes a brake 210 which becomes effective when the motor stops. It serves to hold the telemotor against the restoring action of the centralizing springs, and also to stop the motion of the follow-up gear. A rheostat 160 or similar speed-regulating device may be included.