. The street railway review . ucted that freight ears may be intcrrlianged with Ihc Diir-linglon. 114 RAILWAY RIiVIKW. (Vol, XIII. No. 2 NEW TROLLEY RETRACTOR. Tlic ai-i-DiniMiiyinn ciiKraviiiK illuslralrs a Irollry riiraclor wliiclihas lucn patcnti-d recently ami is known as llic HufTinan-luwerstrolley protector, which will be of interest lo our readers. Thedevice is contained in a small wooden box placed at the rear of thecar. within which is a drnni on which the trolley rope is this drum is a motor spring of sufficient strength lo justkeep all the slack out of the rope
. The street railway review . ucted that freight ears may be intcrrlianged with Ihc Diir-linglon. 114 RAILWAY RIiVIKW. (Vol, XIII. No. 2 NEW TROLLEY RETRACTOR. Tlic ai-i-DiniMiiyinn ciiKraviiiK illuslralrs a Irollry riiraclor wliiclihas lucn patcnti-d recently ami is known as llic HufTinan-luwerstrolley protector, which will be of interest lo our readers. Thedevice is contained in a small wooden box placed at the rear of thecar. within which is a drnni on which the trolley rope is this drum is a motor spring of sufficient strength lo justkeep all the slack out of the rope, in order that the retractive effortof the protector may be quickly applied in case the trolley leavesthe wire. On the same spindle, but independent of the drum, is aspring barrel, containing a spring of sulTicicnt strength to drawdown the trolley pole. This barrel carries a pawl which engages aratchet on the drum: under ordinary running conditions the paw Iis iliscngaged, being held by a hook on a lever, on the opposite end. HOFFMAN-POWERS TKOLLEY IKOTICCTOR. of which is the armature of an electromagnet. This hook not onlyprevents the engagement of the pawl with the drum, but it preventsthe spring barrel from rotating. From each side of the trolley head poised wire connectorsproject laterally; these are insulated from the trolley pole, but arcconnected to the ground through the electromagnet in the protectorbox and a switch. These projecting wires are located so that theycan not touch the trolley wire while the wheel is in place, but theymake contact as soon as the wheel leaves the wire. The electro-magnet attracts the armature, which in turn raises the releasinghook, allowing the pawl to drop and the spring barrel to come intoaction. The latter now engages with the drum and both springsunite in drawing the pole downward, where it is held out of reachof the cross wires and overhead work. Tests extending over a considerable period show that the trolleywheel does not
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
