Patent GB-190525141-A (GB)
Title: Improvements in or relating to Cranes
Inventor: ABEL NIELS ANDERS HANSEN
Filed: 1905-12-04
Granted: 1906-12-04
Abstract: 25,141. Abel, N. A. H. Dec. 6, 1904, [date applied for under Patents Act, 1901]. Cranes.-Relates to cranes or transporters for hoisting and distributing building and other materials in which a runway jib of variable outreach is supported by an extensible post, and comprises means for suspending and slueing the jib, and building up the crane post with the jib in position ; arrangements of the winding ropes are also described for traversing the load carriage and for operating the extension of the jib. The arrangement of a counterweight for balancing the jib is also described. It is stated that the two latter features do not form part of the present invention, but are fully described in Specification No. 25,843, A.D. 1905. The crane post consists of two portions. The lower part a is formed of curved plates riveted together along outwardly-bent horizontal and vertical flanges. In this lower part rests, by means of an external Hange c, an upper part b constructed in the same manner but having the flanges arranged internally. The jib is suspended by guys 1 from a swivelling eye, and is slued by horizontal worms h engaging a wormwheel i on the post b. Revolubly mounted between angle-iron rings f is a plate e carrying downwardly-depending guides d curved in an arc of a circle having its centre in the swivelling eye. These guides engage between angle brackets g on the jib so as to permit slight relative movement between the jib and crane post due to irregularities of balance. When lengthening the lower part a, the worm-wheel i is raised in the position shown in dotted lines in Fig. 3. The worms h then engage worm-wheels m integral with vertical screws 3. The screws 3 sit in sleeves l connected towards the lower extremity by a chain q and resting on the external flanges of the lower part a. When the screws are rotated, the upper part b is raised by the projecting flanges so that an extra row of plates can be built upon and secured to the top of the lower part a. The upper part b can then be lowered to rest again on the flange c. The jib is constituted by two double guides r between which slide the guides u of the jib extension. The jib extension is supported by ropes x, y passing to the drum 4, and is projected by ropes 5 secured to the jib and passing round sheaves 6, 7 also to the drum 4. The hoisting-rope is fixed at one end to the outer end of one of the guides r, and passes to and from the load sheave on the travelling carriage 8 by sheaves at each end of the jib extension and thence to a winding-drum (not shown). The traversing-rope passes from the outer end of the trolly round sheaves at the outer end of the extension, to a sheave at the inner end, and round other sheaves on the main bridge to a winding- apparatus and thence back to the carriage. The arrangement of the ropes is such that no vertical motion of the load takes place during movement of the jib extension or of the carriage. The movable portion of the jib and the load are counterweighted by a ballast box or trolly 26 running on rails 27 and carrying a segment of a double sheave 29. The chain 30 working the trolly is attached at one end to one member of the pulley 29 and passes by sheaves 31, 32 back to the other member. The axle of the pulley 29 carries four arms 33, two on each side, provided with notches wherein are inserted bars 34 connected to brake levers 36 pivoted at one end 40 and weighted at the other and carrying blocks acting upon sheaves on one of the truck axles. The brakes are automatically released when the chain 30 is actuated from gearing 46, that is to say when the counterweight is in motion.