Patent GB-196714-A (GB)
Title: Apparatus for indicating or recording the periodic motion of a rapidly moving or vibrating body
IPC: G01P3/40
Filed: 1922-02-06
Abstract: 196,714. Savage, L. G. Feb. 6, 1922. Indicating, optical devices for; recording particular operations.-Apparatus for examining the periodic motion or vibration, for example, the valves of an internal combustion engine or coil springs, comprises a stroboscopically illuminated lamp, a device carrying said lamp and adjustable in relation to different points in the cycle of operation of the body, magnifying gear for transmitting such adjusting movement to an index and scale, or a recording point and record surface, and means for rotating the scale or record surface and for adjusting the phase of illumination of the lamp. As shown in Figs. 1, 2, the lamp 10 is mounted in a holder 11 which is provided with a slit 12 and is carried by a horizontal axis 13 and vertical axis 14 in a support 15 that is clamped to a block or sleeve 16 slidably mounted on a guide post 17. A lever 20, pivoted at 21 or alternatively at 22, has at one end a roller 32 engaging the sleeve 16 and is provided at its other end with a 'bridge piece 25 and roller 33; the said bridge 25 is mounted on a screwed spindle 27 that is rotatable by means of a graduated hand wheel 28 and carries a horizontal extension 34 guided by a rod 36 and provided with a spring arm 37 supporting a needle 26. The record drum 39 is detachably mounted on a turntable 40 adapted to be rotated by a worm and worm wheel from a hand wheel 43 and is formed with a pulley 48 around which is coiled a cable 47 connected to the advance and retard mechanism of the stroboscope. The lamp support 15 may carry one leg of a stirrup 49 in the opposite leg of which is a slit 51 at the same level as the slit 12. An external lamp is used to obtain one end of the travel of the body 52 under observation, after which this lamp is switched off and the lamp 10 is switched in and the screwed spindle 27 rotated until the beam of light through the slits is just blocked out by the observed line on the body, the needle is then pressed against the record surface. The drum 39 is then rotated to adjust the phase gear and the screwed spindle 27 is again rotated until the light is just blocked out when another point is pricked on the record surface. The curve produced may be compared with a standard curve by providing an electric contact stem 57 with a point in alignment with the slits 12, 51 and which completes a circuit when the body 52 which is moved step by step to different positions in its cycle of motion makes contact with the stem 57 adjusted by the hand wheel 28. In a modified arrangement the body may carry a screen with a slit which can be aligned with the slit 12. A further modification consists in mounting a pointer 56 on the support 15 which may be aligned with a line scribed on the body 52, an external lamp being used. A third modification shown in Fig. 6, comprises a lamp support 15 adjustable vertically on a screwed spindle 58 that is rotated by worm gearing from a hand wheel 28 on a horizontal shaft 64, the shaft being screw threaded and engaged by a nut 25 having a bridge piece carrying the recording needle 26. The record drum is rotatably mounted by means of worm gearing on a spindle 38. The record sheet may be held on the drum by placing the overlapping ends in a dovetailed recess 71 and securing it therein by means of a rubber covered longitudinal rod 72.