Improvements in or relating to colliery and like 'overwind' gear

摘要

415,191. Winding - apparatus. HEWITT, H., Hill Side, Tunnel Road, Ansley, Nuneaton. March 30, 1933, No. 9554. [Class 78 (v).] A colliery or like winding gear is provided with hydraulic mechanism controlled by a timing device for stopping the engine and applying the brakes if overwinding occurs or a safe speed is exceeded. The mechanism includes a dash-pot device for cushioning the automatic application of the brakes. An oil pump, not shown, driven by the winding engine, forces oil from a sump 2 through a pipe 3 and the cylinder 5 of a piston valve 6 and back to the sump through a pipe 4. The valve 6 has a stem 7 carrying, on a pin 17, a roller 10 in engagement with a cam 8 which is so driven by the engine that it makes less than a complete revolution for the complete travel of the cage. An extension of the pipe 3 is connected to the upper end of a cylinder 11 in which is a piston 12 having a stem 15 with adjustable stops 15a for engaging a lever 16 pivoted on the pin 17. The uppermost position of the piston 12 under action of a spring 13 is defined by an adjustable stop 14. The lever 16 normally holds from turning a pivoted arm 19 which is linked to arms 23, 24 which are operatively connected respectively to brake-applying and enginestopping mechanisms and which are biassed by weights. For most of a winding operation, the passage for oil through the cylinder 5 is unobstructed. Towards the end of an operation, however, the cam 8 elevates the piston 6 partly to close the passage, so that the increasing pressure in the pipe 3 forces down the piston 12 and, eventually, rocks the arm 16, which has risen during this time with the piston rod 7, freeing the arm 19 and causing the engine to be stopped and the brakes to be applied. Similarly, excessive winding speed increases the pressure developed by the oil pump and so stops the engine. The cam 8 is provided with a projection 8a designed to stop the engine if the latter is started to drive in the wrong direction. A branch 3a from the pipe 3 is connected to a cylinder 29. When pressure develops in the pipe 3, it forces down the piston 31a so that a roll 32 on its stem 31 is in position to engage and cushion the movement of an arm 33 carried by the rock shaft 34 of the brake-applying arm 23.