Patent GB-186373-A (GB)
Title: Improvements in visual signalling apparatus for use in connection with colliery and like winding
IPC: B66B19/06
Filed: 1921-05-23
Abstract: 186,373. Midgley, E., and Hopkinson, R. A. May 23, 1921. Mine and colliery signals; mechanical telegraphs. - In a mine signalling apparatus of the kind in which a pointer is moved step by step over a dial, duplicate semaphore arms are provided which are operated together by the " men " signal and tripped independently by the movement of the cages. The first impulse of a fresh signal causes the pointer-releasing catch to be held off during the whole up-and-down movement of the pull-rod. An arrangement of lamp signals is also provided. In the example illustrated, the indicator finger is moved by a ratchet-wheel 14, controlled by an actuating- pawl 17 and a holding-pawl 18. The latter has at its lower end a pin 23 adapted to engage a hook 24 or a floating bar 25 pivoted at 8 to an arm 26 carrying a roller 27, the bar 25 being so weighted that the hook 24 tends to drop clear of the pin 23. A pull on the wire 11 lifts the weighted rod 10. This sounds a bell through the arm 58. An extension 36 free to move between the collar 75 and head 76 raises the rod 34 connected to the plunger of dashpot 33. The thickened portion 30 of rod 10 moves the floating bar 25 laterally, thus freeing the ratchet-wheel 14 from the pawl 18 and allowing the pointer to be returned to zero by the weighted rack 15, and pinion 19. When rod 10 falls, the pawl 17 steps the pointer round to the first signal and the hook 24 falls clear of pin 26. If several pulls are given in quick succession the pointer moves to further positions, but if a sufficient pause is made rod 34 falls and the pin 76 thereon causes hook 24 to be raised and engage pin 23 so that any subsequent pull restores the pointer to zero. The fall of rod 34 is hastened in its initial stage by the pressure of the arm 36 on the collar 75 thus ensuring expansion of the leather of the plunger to make a good joint. When the signal "men to ride," in this case "3," is given the spring-controlled catch 38 enters a notch 37 on the rack rod 16 and a subsequent signal moves two arms 44 to a displayed position, where thev are held bv catches 47. The catch 38 is then disengaged by means of an inclined tripping-bar. The catches 47 are tripped by pins 49. 50 on a rod 48 moved by the depth-indicator, the arrangement being such that the arm corresponding to the cage at the pit head is tripped immediately while the other stays in view till the end of the wind. If the number of pulls is in excess of three, a trip catch 51 tilted by the fixed pin 52 prevents engagement of the catch 38 with the notch 37. Cancellation of the signal by compliance is effected by a cam 53 on the depthindicator bar 48 which moves a sliding bar 54 carrying an arm 55 to disengage momentarily the pawls 17, 18 from ratchet 19. Spring buffers are provided where desirable. At the beginning of each signal a notched disc 63 on the ratchet spindle allows a switch arm 64 in series with a white light to operate. The same disc operates similarly a switch arm 65 controlling a green light G on the signal " men to ride." The circuits of both these lights is broken by arm 66 on the descent of dash-pot rod 34. A red lamp R operates during the whole time a semaphore arm is raised and the arm 66 is depressed, through operation of a contact 67.