Publication: Western Electrician
Chicago, IL, United States
Safety Arc-lamp Pulley.
A new arc-lamp pulley is now on the market, being another product of the West. Three years after Fletcher (of Ohio) had introduced sleetproof pulleys, Lounsbury and Morgan (both of Chicago) perfected the first of the so-called lamp-supporting or safety pulleys, whose use has since become so general. Now another Chicago inventor, Albert Scheible, has brought out the new type illustrated here, which combines a smooth-acting safety arrangement with a weatherproof housing. It has only two moving parts, the sheave over which the rope runs and the hook-knob to which the lamp is fastened. When the latter enters the guideways in the pulley casing it first strikes an inclined guide, up which it climbs until the angle-between the knob and the guide becomes too steep for it to move farther. There it is stopped by its own friction without striking any barrier which would halt it abruptly and jar the lamp out of adjustment. Slackening the rope allows the knob to slide to a seat, after which another pull automatically releases it. The knob part has a clamp for the rope, and the familiar Ajax snaphook for the lamp, and for series circuits it is fitted out with a high-voltage cross-arm as shown. Both types have been thoroughly tested in practice and are now offered to the trade by the Ajax Line Material Company of Chicago.