Patent GB-191421706-A (GB)
Title: An Improved Span Rope Side Traversing, Arc, and Incandescent or Gas Lamp, Automatic Connecting, Suspending, and Lowering Device.
Inventor: STEVENSON JOHN
IPC: F21V21/38
Filed: 1914-10-29
Granted: 1915-10-29
Abstract: 21,706. Stevenson, J., and Williams, O. R. Oct. 29. Overhead travellers and transporters.-In arrangements for supporting lamps by means of a span rope over a street &c., means are provided for raising the lamp into suspension on a trolly, traversing the trolly along the span wire to a fixed lighting-position, and further raising the lamp into connexion with electric or gas supply fittings. The lamp is returned by lowering it to a third suspension position on the trolly, traversing the trolly to the lowering position, and releasing the lamp from the trolly. The arrangement comprises a fixed fitting clamped to the span rope and having electric or gas supply fittings, a trolly with a three-position suspension device, and a twin winch or pair of winches for operating the lifting and traversing ropes. In the form shown, the trolly B is traversed on the span rope A by means of a rope w<1> passing over a pulley h on the fixed fitting a, a<1>. The trolly carries a guide-pulley V<2> and supports members C, E, and a cap D. Within the member E, Fig. 2<c>, is a slotted tube G through which passes the lifting-rope w attached to a member F on the lamp fitting Z. The member F carries one or a pair of pivoted arms M each having a pin i adapted to engage a series of cam surfaces on a plate J on the member E. When the lamp is first raised and lowered, the pin i rests in the first suspension position P', as shown, taking the weight of the lamp off the lifting-rope. On raising and lowering a second and third time, the pin i comes into the second and third positions P<2>, P<8>. In order to prevent the lamp from being raised into the second suspension position except when it has been traversed into the lighting position, a pivoted shutter W has a step t limiting the rise of the member F; and the shutter W has arms Y, Y<1> which are engaged by arms Y<2>, Y<3> on the fixed bracket b when the lamp is in lighting-position, removing the shutter W from the path of the member F. The fixed fitting in the lighting position comprises a bracket b mounted beneath a p@e of members a, a<1> forming a split tube and clamped on the span wire A, the member a forming a rail for the trolly. In order to ensure correct engagement, a fork bf on the bracket b engages rollers bg on an adjustable bar on the cap D of the movable fitting. The fork bf may carry straps cd clamped to an upper span rope AA and enclosing a cover CC for the trollv in the lighting position. For three-arm spans, Fig. 2<E>, one arm R<1> is branched from the end of the split tube a, a<1>, and another arm R<2> is formed by carrying the rope A through the split tube. In operation, when the winch drum controlling the rope w<1> is held against movement, the rope w serves for lifting and lowering the lamp, and when the rope w<1> is freed, the rope w serves to traverse the trolly from the lighting position to the side of the street &c., while the rope w<1> is used for traversing the lamp from the side of the street to the lighting position.