GB931409A - Impact recorder - Google Patents

Abstract

931,409. Impact-recording devices. PRINTING, PACKAGING & ALLIED TRADES RESEARCH ASSOCIATION. Jan. 16, 1961 [Nov. 9, 1959], No. 34375/59. Classes 106 (2), 106 (3) and 106 (4). An impact - recording device comprises mechanically- or electrically-operated mechanism moving a roll of recording paper at a predetermined constant speed, a set of shock responsive elements each coupled to a stylus and together producing a continuous record on the paper of shock in any direction, and further shock-responsive means adapted, on receipt of shock, momentarily to impart additional accelerating movement to the paper to expand the time scale marked off on the paper by an independently-operated stylus. As shown, the waxed recording paper 9, feed-roller 6, magazine roller 7, take-up roller 8, time-marking stylus 48 and the first set of shock-responsive elements 14, 15, 16 each provided with a stylus 18, 19 and 20, respectively, are housed in a casing 1 mounted in a container 3 which is placed in a package the transit hazards of which are to be investigated. A clockwork motor 4 drives via gearing 49, the feed roller 6 and a circular toothed plate 51 rhythmically depressing a spring-loaded rod 30 carrying the stylus 48. A belt 13 drives the take-up roller 8 slightly faster than feed roller 6 to keep the paper taut. The styli 18, 19, 20 are carried on rotatable pillars 21, 22, 23, respectively, which also carry counterweights 25 each producing a gravitational torque about a different one of three mutually perpendicular axes, the displacement amplitude of the styli being limited by springs 24. The feed roller 6 is rigid with milled driving wheels 41 which can be engaged so as to increase the rate of rotation, by either of a pair of pawls such as 40 (Fig. 3) each pair (there are three) being mounted on plates 37, 42, 43, respectively. The plate 37 moves in the y-z plane against springs 38 for impact in the xdirection such impact pivoting an arm 32, loaded with a mass 31 and constrained by spring 35, about a spindle 33 carried between pillars 34, a linkage 36 then moving plate 37. Plates 42 and 43 move orthogonally under their own weight for impact components in the y-z plane, the associated pawls acting on a common milled wheel 41. One pawl of a pair is active for each sense of movement of the associated plate, the pawl that was inactive during movement in a particular sense becoming active during the return movement of the plate caused by the springs 38, and the acceleration on the feed-roller is always in the same sense. A similar twin-pawl and ratchet arrangement between the circular plate 51 and a milled wheel 52 allows acceleration of the feed-roller without interfering in the clockwork drive to the timing stylus.