Patent GB-699948-A (GB)
Abstract: 699,948. Linear-dimension gauges. UNITED STATES PIPE & FOUNDRY CO. May 7, 1952 [May 7, 1951], No. 11537/52. Class 106 (ii). A gauge for measuring the wall thickness of a tube comprises a support bed for the tube to position it horizontally, a beam supported at one end and having its free end extending over the bed, so that the beam enters the tube when the beam and tube are moved relatively longitudinally, a follower carried by the beam adjacent the free end thereof for contacting the inner surface of the tube wall, a vertical linear scale carried by the beam adjacent the follower, and a device for reading the scale. The bed is formed by a plurality of rollers 4 journalled in bearings 5 mounted on a frame 1. The tube or pipe 8 has a bell 9 at one end and a spigot 10 at the other end. The rollers are concave as shown in Fig. 3. A beam 12 is supported in caritilever fashion by a strap 14 and saddle 15 over the bed. A roller 16 is mounted in the end of the beam which is formed from a hollow tube. Adjacent to the follower 16 is a scale 22, Fig. 6, illuminated by a lamp. 24. A shield 26 is positioned between the observer and the lamp, and is provided with an aperture 28 to permit reading of the scale by means of a telescope 29 supported on a standard 30, adjacent the fixed end of the beam 12 and in alignment with the bore thereof. The beam 12 is provided with apertures 31 to eliminate heat waves within the beam which might distort the scale reading. A jack 32 is provided adjacent the fixed end of the beam for lifting the free end thereof to facilitate insertion into the bore of the pipe to be measured. Longitudinal movement of the pipe 8 during measurement is effected by means of a movable carriage 36 bearing two plates 37, 39, which embrace the bell mouth and pull or push the pipe along the roller bed. Sets of skids 40, 41 are provided on either side of the carriage 36 to facilitate loading and unloading of pipes in succession, ungauged pipes being stored on one side and gauged pipes on the other. Two hydraulic rams 48 coupled to shaped rollers 43 are moved inwards to position the end of a pipe to be measured centrally over the bed and the pipe is then aligned finally by means of rollers 61 supported on vertical spigots 63, adjustable symmetrically towards and away from the centre line of the bed by means of the screwed shaft 66 and wheel 70. Between the fixed support 13 for the beam 12 and the remote end of the bed are frame members 73 engaging vertical guides 74. On each of the frames 73 is a pair of rollers 75 keyed to shafts 76 mounted in bearings 77. The rollers 75 are normally positioned below the bed but may be raised on the frames 73 by jacks 78 so as to embrace the pipe and rotate it on its axis by means of the motor driven gear box 82 and sprocket drive 83 to one of the rollers 75 as shown in Fig. 5. Before operating the gauge, the follower roller is first zeroed on the roller 4 beneath it. During operation of the gauge the pipe is supported only by the roller 4 beneath the follower roller 16 to eliminate errors due to bowing of a pipe, the plates 37 and 39 on the carriage 36 being adjusted so as to lie just below the bell 9 and out of supporting contact with it. When the pipe to be gauged is in position the pipe support rollers 42 are withdrawn to allow the carriage 36 to pass between them to push'the pipe along the bed. The portion of the pipe wall being gauged may be varied by means of the motor driven rollers 75 as required. The carriage 36 is driven by means of a motor 56 gear box 55 and chain 51 passing over driven sprocket 52 and idler sprocket 53 adjustable in a slot 58 in the main frame 1.