Patent GB-374172-A (GB)
Title: Improvements in or relating to flaw detectors
IPC: G01N27/83
Filed: 1931-03-13
Abstract: 374,172. Magnetic tests : couplings. SPERRY PRODUCTS, Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A. -(Assignees of Drake, H. C. ; 65, Lincoln Boulevard, Hempstead, Long Island, New York, U.S.A.) March 13, 1931, No. 7779. Convention date, March 18, 1930. [Classes 37 and 38 (i).] Electromagnetic rail-flaw detector apparatus mounted on a travelling car is provided with rail marking devices energized on traversing the flaw, means being provided for maintaining the marking devices energized until the mark is effected. In order to render the marking apparatus ineffective when the detector passes over rail joints, levers engaged by the tie-plates open the marking circuit. The rail-marking device comprising a paint gun is mounted behind the detector a distance sufficient to compensate for the lag in operation of the marker. The detector and marker are raised and lowered together in relation to the rails. Electromagnets 20 which are energized through an amplifier close contacts 22 in the circuit of the flaw recording electromagnet 23 and also energize electromagnet 25 which closes contacts 26 energizing relay 27 for connecting the power supply to the paint gun electromagnet 30. Electromagnet 25 is provided with a holdon coil 251 which remains energized until the full movement of armature 28 breaks contacts 29<1>. In order to prevent the paint gun from being operated when the trolley passes over rail joints, levers 40, 401 engaged by the rail tie-plates close contacts 41, 411 thereby opening contacts 44 in the circuit of electromagnet 25. At the same time closure of contacts 45 energizes the joint-recorder-magnet 51. The Specification as open to inspection under Sect. 91 (3) (a) comprises also fluid-pressure mechanism 60 .. 63 under the control of the driver or test operator for actuating the brushes 14 and holding them in contact with the rail. It also describes means for moving the detector carriage 70 independently of the brush carriage 11, the detector carriage being loosely mounted on its support 71 by bolts 75 and springs 78, the support 71 being secured to the brush carriage. Means is also described for maintaining the flaw-detector mechanism at a substantially constant distance from the rail, these means comprising grooved or solid wheels engaging the rails and leaving the detector-box slightly spaced therefrom. Alternatively, the carriage 70 may be provided with shoes 74. The detector coils may be housed in rollers carried by pivoted and spring-biased levers 83, Fig. 6 (Cancelled), or they may be carried in a block 90, Fig. 10 (Cancelled), the block being resiliently held on the rail by levers pivoted at 91. In a further modification, the detector coils are carried on the axle of the rollers. This subject-matter does not appear in the Specification as accepted. The Specification as open to inspection under Sect. 91 (3) (a) comprises also hand testing mechanism for detecting flaws, one rail contact 131 being attached to the piston 96 of an air cylinder 95, the other contact 141 being in the form of a hand-operated hook and cam device 97 .. 100, Fig. 9 (Cancelled). This subjectmatter does not appear in the Specification as accepted.