Showing papers on "Slewing bearing published in 1977"

Jib crane tipping moment limitation device - uses stretching or compression load in supporting surface to compute value

Abstract: The tipping moment limitation device is for jib cranes, including slewing ones, and similar machines. The stretching or compression of the material in the supporting surface at the slewing ring or anchorage points is used by a computer to calculate an actual value, proportional to the total tipping moment at the tipping point of the crane. The stability base of the crane can be taken as a variable value when determining this actual value. To emit a signal on reaching the max. tipping moment the actual value can be compared with a desired one proportional to the crane stability base.

Hoisting equipment transporting in three dimensions - has slewing bearing block with parallelogram linkages supporting lifting arm

Abstract: The hoisting equipment lifts and transports loads in three dimensions, having a bearing block (3) slewing on a vertical axis through 36 deg. The block supports two lifting linkages alongside each other, each comprising a parallelogram and a guide linkage, the latter allowing movement in a straight line and coupled to the parallelogram linkage and lying in a common vertical plane including the slewing axis. A lifting arm (4) forms for part of its length the outermost side of each parallelogram linkage and supports the load at its lowest end (21). A top arm (6) forms for part of its length the uppermost side of the parallelogram, sliding at its inner end in a vertical slot (16) in the bearing block, while its outer one is attached to the lifting arm top end. The connecting point between the parallelogram and guide linkages forms a movable mechanical support for the lifting linkage.