Patent GB-503440-A (GB)
Title: Improvements in or relating to linear dimension guages
IPC: G01B5/06
Filed: 1937-12-14
Abstract: 503,440. Linear - dimension gauges. OEHMICHEN, E. E. Dec. 14, 1937, Nos. 34644, 34645, and 34646. Convention dates, Oct. 6, Nov. 17, and Nov. 17. [Class 106 (ii)] The thickness of a strip &c. during a rolling operation is measured by two members adapted to move towards and away from each other and of which the possible approach travel corresponds to the desired thickness, the members being in the form of screws one of which is adjustably fixed while the other is turned about its longitudinal axis in one direction by a cam and in the other direction by means of a spring. The frame 1 carries a roller 2, a second roller 4 being carried by a movable arm 6 pivoted at 11 to the frame 1 and connected to the latter by a spring 20. A hardened steel point 9 is formed on a screw 10 and is opposed by a micrometer screw 7 having a rounded head, as shown. The screw 7 is moved towards and away from the part 9 at regular intervals by a motor-driven cam 18 acting on a spring-controlled slide 17. A rack 15 on the slide engages a toothed wheel 12 fast with the screw 7. The piece to be gauged is passed between the rollers and they separate according to its thickness. The screw 7 is screwed up until it touchesthe point 9, whereupon the rack 15 can move no further and the thickness is read off on a graduated drum 13 against a fixed pointer 14. In a modification, the rack drives a long pinion on a shaft carrying the drum and gearing with a wheel on the screw 7. A hollow shaft surrounding the drum shaft is driven from the cam-shaft and carries a shutter. The result is that the drum graduations are only exposed for an instant when stationary and may be easily read. The cam is such that the period of stoppage is relatively long compared with the period of movement. Fig. 3 shows a form in which the screw 7 has a long shaft 21 upon which is a bevel gear 22 and also a collar with a projection 39 which is struck periodically by a projection 38 on a motor-driven shaft 40. The projection 38 moves the projection 39 and allows it to escape while a spiral spring 32 brings the projection 39 back in the opposite direction until it meets a stop. This movement is transmitted by the pinion 22 to a pinion 23 on a hollow shaft 24 carrying a projection 25. This is pressed by a spiral spring 30 against a pin 27 on a plate 26 carried by a shaft 28 on which is a pointer 31. A cam 35 on the shaft 40 actuates a rod 37 against the influence of a spring 33 and causes a slightly compressible brake shoe 34 to engage the disc 26. In operation, the projection 38 having moved 39 away from the extreme position causes the screw 7 to unscrew. The part 39 escapes and the part 7'is screwed up again under the influence of the spring 32 until contact is made with the part 9. The brake 34 is released during a very short time when contact is made between parts 8, 9. The apparatus is originally set by placing a standard shim between rollers 2, 4. The pinion 22 and mechanism it drives may be at the end of a long flexible shaft to secure distant indication, or an electric hydraulic or pneumatic transmission system used. Any suitable recording apparatus may be used. In another form, the parts 7 and 9 are mounted in a rigid U-shaped frame perpendicular to the path of the part being checked. This frame may be reciprocated on guide rods in the direction of the above-mentioned path at such speed that there is no relative movement between the strip and frame when the. material is pinched between the screws to obtain the measurement. The system may also be moved in a direction at right-angles to the above path to check different zones of the material. Another example of this form is described in which the screw 7 is driven through friction gear from a motor carried by the reciprocating frame. The latter is moved in one direction by the sheet itself and in the other by a spring, grips being automatically thrown into and out of operation by engagement with abutments. Stops at each end of the travel also reverse the motor. In the forms having rollers compensation for temperature may be effected by fitting a pyrometer element in the roller which may be used to operate a relay to effect a slight movement of the lower screw or the rollers may be constructed so that cooling fluid may be circulated through them.