SE419331B - BOMLYFTKRAN - Google Patents

Description

The YQÛTSRS bearing discs at the end of the boom are unchanged in relation to each other independently of the movements of the boom. Thus, the boom can be swung in a radial direction and broken at the joint in the desired way, and the load always remains horizontal and at a constant height above the ground.

An embodiment of the invention in a crane with a rigid boom is characterized in that the intermediate rope pulleys lie at the tower and that the lifting ropes coming from the rope drum make a bend around the intermediate rope pulleys and the pulleys at the end of the boom, so that the bends cross. With a crane with a rigid boom, the same properties are achieved as with a articulated boom crane, so that the load is kept horizontal and at the same height above the ground, regardless of the radial movements of the boom.

Exemplary embodiments of the invention are described in the following with reference to the accompanying drawings, in which Fig. 1 represents an boom lift crane according to the invention with a hinged boom, Fig. 2 shows a boom lift crane according to the invention which has a rigid boom.

The crane in Fig. 1 comprises a portal 1 and above it a rotating carriage 2 rotatable about the vertical axis. At the rotary carriage 2, a lifting boom has been rotatably mounted in the vertical plane. At the end of the boom 4, at the joint and in the tower of the crane, there are rope pulleys 5, 6, 7, 8, 9, over which the lifting ropes 10, 11 go from the rope drum 12 to the load carrier 13. The shafts of the lens pulleys 5, 6 at the end of the boom 4 are at a distance from each other. The axes of the intermediate line discs 7, 8 are also at a distance from each other. The lifting ropes 10, 11 run in a cross between the pulleys 5, 6 at the end of the boom 4 and the intermediate pulleys 7, 8 at the joint, and the positions of the pulleys at the end of the boom and for the intermediate pulleys are unchanged in relation to each other regardless of the movements of the boom. When a boom crane according to Fig. 1 is moved with the load 14 from the outer extreme position to the inner extreme position, the load carrier 13 and the load 14 remain substantially horizontal and the height of the load above the ground is substantially constant throughout the movement, because the lifting ropes 10, 11 run in cross between the lens discs 5, 6 and the intermediate lens discs 7, 8. ._ p .. x ~ _._. <», fl, -.- ~ M ... tm .... ,,, _., o ...,. zwwwiß-n ... ~.:, .....-- w. U-.ffrw fl vf- f m. -. _ - -> ~ _ -.a-- ~ i ”7eeå ¥ ¿¶s'¿; ~ s" š ”¿. **" * When the lens pulley 5 1 the end of the boom 4 when turning the boom is turned from above the rope pulley 6 to a position below it, the intermediate rope pulley 8 rises above the intermediate rope pulley 7, whereby the lifting rope 10 on the rope pulleys 5, 8 is tightened and holds the load carrier horizontally and at an almost constant height above the ground surface.

The crane in Fig. 2 has a rigid boom 15 with pulleys 1a, 17 at its end, the axes of which are at a distance from each other. At the crane tower there are intermediate line discs 18, 19 whose axes are also spaced apart. The lifting ropes 20 coming from the rope drums l2 run over the intermediate rope discs l8 and l9 to l6 and 17 at the end of the boom 15 and back to the intermediate l8 and l9 so that the lifting ropes make bends. Now lift again to the pulleys at the end of the boom 15 and the pulleys the pulleys the ropes go on to. thus, the load carrier means at the ends of the lifting ropes 20, 21 will remain horizontal and at an almost constant height above the ground.

It will be apparent to one skilled in the art that the various embodiments of the invention may be varied within the scope of the following claims.

Claims (1)

A PATENT REQUIREMENT Boom crane at which a rotary carriage (2) rotatable about a vertical axis has been mounted, a boom (3, 4) pivoting in the vertical plane in whose end lens discs (5, 6) are arranged whose axes are at a distance from each other and over which lifting ropes (10, 11) go from a rope drum (12) in the frame of the crane to a load carrier (13), and in which intermediate pulleys (7, 8) whose axes also lie; at a distance from each other, are arranged between the rope pulleys (5). , 6) at the end of the boom (3, 4) and the rope drum (l2) .at the joint of the boom, characterized in that the lifting wires (10, ll) run crosswise between the pulleys (5, 6) at: the end of the boom ( 3, 4) and the intermediate discs (7, 8) at the joint and that the positions of the lens discs (5,6) at the end of the boom and the intermediate discs (7, 8) at the joint are unchanged in relation to each other independent of the movement of the boom.