GB119514A - Improvements in Mine Signalling Apparatus. - Google Patents

Abstract

119,514. Millar, W., and Strachan, J. Oct. 1, 1917. Mine and colliery signals.-Signalling apparatus for use in mines &c. has two pointers, operated independently but by the same wire, &c., one registering signals complying with legal requirements, the other registering signals determined by the colliery &c. officials. Signals are cancelled on compliance by pneumatically operated mechanism worked by the winding engine. A spindle c, provided with a ratchet wheel operated by a pawl l on a sliding frame k reciprocated in the usual way, has a pin f<1> engaging a pin f<2> on a second ratchet wheel h carried by a loose sleeve d to which the indicating pointer e is attached. The ratchet wheels are respectively held by detents i<1>, i, the former being normally held out of engagement by a cord i<7> secured to the piston i<4> of a time-lag device, but lowered into engagement when a signalling impulse raises the frame k. After a pause, the spindle c returns to the zero position, the pointer remaining to register the signal until complied with, or until the first impulse of a succeeding signal which releases the detent i by means of a projeotion k<2> on the frame k. To prevent the pointer from moving more than one step at a time, a third ratchet wheel is provided with its teeth in the reverse direction and co-operating with a pawl u<2> carried by an arm u<1> loosely mounted on the sleeve d. Upward movement of the frame k releases the pawl u<2> by means of an arm u<5>, and the arm u<1> is moved over to the left by a weight u<7>, the pawl u<2> engaging the next tooth of its ratchet wheel. Descent of the frame k moves the ratchet wheel and with it the arm u<1> to the right. Movement of the arm u<1> is limited by stops u<6>. The second pointer v is operated by a ratchet wheel v<2>, and the centre on which the signalling lever (not shown) works can be raised or lowered so that the pawl l can be made to operate the lower or upper indicator at will. When the upper indicator is in use, audible signals are given in the usual way on a gong A, but when the frame k is lowered to operate the pointer v, the gong connexion is slack so that no audible signal is given. Both pointers are returned to zero by engineoperated means acting on the detents through levers r. The engine, when running, operates an air pump n so as to raise a weighted piston n<2>, thus causing a pivoted lever p' to depress one arm q of a T-shaped lever, the other arms of which are connected by means q<2> with the levers r When the engine stops, air escaping through an adjustable valve n<4> allows the piston n<2> to fall, the lever q being again operated to cancel any signal which may have been registered during the running of the engine. The lever p' is also connected by means s with a plate t, which is raised or lowered to exhibit the words " raise " or " stop " when the engine is stopped or running.