Patent GB-345362-A (GB)
Title: Improvements in course recording or like apparatus for use on ships or the like
IPC: G01C17/00
Filed: 1929-12-30
Abstract: 345,362. Course-recording apparatus. HOLMES, E. L., 118, Cranbrook Road, Ilford, Essex. Dec. 30, 1929, No. 39735. [Class 97 (ii).] Apparatus for use on ships &c. for indicating the component distances travelled along and at right-angles to a set course comprises means for integrating the component speeds in the said directions, and continuously-operative automatic means for correcting the speed factor to compensate for variations in propeller slip. The results of the integrations are indicated by pointers moving over dials. Fig. 1 shows the compensating device used in conjunction with propelling means consisting of two propeller shafts 1, 1a, these being arranged to drive the elements 5, 5a, of a differential gear, the intermediate element 8 of which drives a gear wheel 9 at the mean of the propeller speeds. A friction disc 10 secured to the wheel 9 drives a wheel 11 mounted on the shaft of a transmitter 14 connected to a step-by-step motor m. The desired compensation is effected by causing the wheel 11 to be moved across the face of the disc 10 when the propeller speed varies, the wheel 9 being geared to a shaft 19 carrying a governor 20 which operates on one end of a lever 21 pivoted at 23, the other end of the lever being provided with curved slots engaging pins 24, the slots being shaped to effect the desired movements of the wheel 11 on the particular ship &c. on which the apparatus is to be used. In the apparatus for indicating the component distances travelled along, and at right-angles to, the set course, the motor m, Figs. 4, 5, and 6, drives a shaft 107 geared to a shaft 110 on which are mounted two friction discs 111, 112 respectively engaging friction wheels 113, 118. The wheel 113 is mounted in a housing 113a attached to a yoke 114 which is supported by rollers 116, 116a on a track 115 and the wheel 118 is similarly mounted in a yoke 119 supported on a track 120. The wheel 113 drives a shaft 123 which is geared to indicators 141, 142 showing the component distance travelled along the set course, and the wheel 118 drives a shaft 125 geared to indicators 152 153 showing the component distance travelled at rightangles to the set course. The shaft 125 also drives a steering-pointer 149. The friction wheels 113, 118 are arranged to be displaced across the faces of their driving discs in accordance with the course being made by means of a step-by-step motor M controlled by the ship's compass and geared to a sleeve 161, Fig. 5, rotatably mounted on a shaft 162. A spider 165 secured to the sleeve carries a repeater compass-card 166 and a clutch member 167 coacting with a clutch member 168 carrying pointers 170, 170a. The shaft 162 carries a gear 171 provided with a block 173 movable in a vertical slot in the yoke 119 so as to displace the latter along its track 120. The gear 171 drives a gear 174, Fig. 4, mounted on a shaft 175 which is connected by an adjustable coupling 183 to a shaft 175a driving a gear 177 which carries a block 182 for displacing the yoke 114. The adjustment is such that when the ship is steaming on the set course the wheels 113, 118 are respectively at the edge and the centre of their driving wheels. A hand-wheel 187 is provided for disengaging the clutch 167, 168 and rotating the shaft 162 by hand for initial adjustment of the indicators. Provision is also made for resetting the indicator hands by mounting them frictionally on their spindles. Specifications 269,781, [Class 97 (ii), Surveying &c. instruments], and 273,920, [Class 106 (i), Calculating &c.], are referred to.