GB660791A - Improvements in or relating to navigational apparatus - Google Patents

Abstract

660,791. Counting-apparatus. BENDIX AVIATION CORPORATION. March 5, 1948 [March 6, 1947], No. 6940/48. Class 106 (i). A navigational appara. tus, e.g. for aircraft, consists of a unit producing data representing latitude and longitude, and remote data - reproducing means comprising latitude and longitude indicating counters 37, 77 respectively, each wheel of which has two rows of numerals, Fig. 5, corresponding to the two hemispheres, and manually movable means 58, 89 for selectively exposing to view the appropriate row of each wheel and preselecting the same row for co-operation with recording means. As shown in Fig. 2, latitude and longitude are indicated on counters 13, 82 respectively, also having separate numeral rows for each hemisphere and driven by gearing (not shown), and time is indicated on a counter 124. These indications are reproduced on counters 37, 77 and 145 respectively and may, if desired, be printed on a paper tape 95. Each rotation of the shaft of counter 13 causes a pin 16 or 17 (depending on the direction of rotation) on a disc to close a switch 18 or 19 to send an impulse to a solenoid 26 or 25, Fig. 3. Each solenoid has its plunger connected by a pivoted lever 45 or 42 to a pawl 41 or 40 which, when the solenoid is energized, engages a ratchet 39 to move the counter 37 one step in one direction or the other. Movement of the counter 82 is similarly repeated by counter 77 which is similar in all respects to counter 37. The counter 124, which is driven by, or may be replaced by, an ordinary clock mechanism, similarly causes impulses to be sent to a solenoid 142, through switch 131 and relay 134, thus causing a pawl 151 to step on the ratchet 150 of counter 145. The numerals of counters 37, 77, 145 are raised so that they can be used for printing as well as indicating, and diametrically opposite numerals correspond. When printing is required, a switch 115 is closed to energize a solenoid 112 to move a bar 96 having hammers such as 102, Figs. 3 and 5, which urge the tape 95 and inking ribbon 107 into contact with the counter wheels, directly for counter 145, and through row-selecting spring pads 110 for counters 37, 77. After printing, the tape is manually drawn out and torn off. The solenoid 112 may alternatively be operated by clockwork. The pads 110 for counter 37, for example, are carried by spring arms 108 on an extension of a shutter 58 which has windows 59 for indicating only one row of numerals of each wheel at a time. The shutter may have hemisphere indications (N and S) thereon, and is moved, when changing hemispheres, by turning a knob 64, Fig. 2, which operation also closes a switch 65 or 72 to energize solenoid 25 or 26 to move the counter one step so that the indication of the new rows of numerals is zero. Resetting knobs such as 56 are each associated with a crown wheel which may be engaged with the ratchet, e.g. 39, of the corresponding counter by movement against a spring such as 57. The remote indicating and printing mechanism may be located in a housing 160.