GB352225A - Improvements in grabs - Google Patents

Abstract

352,225. Grab-buckets. BARNARD, D. J., 8, Strathfield Gardens, Barking, Essex. June 25, 1930, Nos. 19345/30 and 11577/31. [Class 78 (iv).] A single rope ring discharge grab has means for maintaining the bucket sections in the. open position and for taking the stresses tending to close them, comprising one or more vertically disposed rods carried by a part pivotally mounted on the head of the grab and arranged to coact with means carried by the cross-beam. The hauling rope 29 passes through the tipping ring 28, round a sheave 31, upwardly and over a sheave 32, downwardly and around a sheave 33, upwardly and over a sheave 34 and finally downwardly to the crossbeam 23. The thimble 30, Fig. 6, in the grab-head 27 carries a slidable sleeve 37 which is slotted to engage the lower ends 39 of the ring-engaging hooks 36. The lower end of the sleeve has angular extensions, Figs. 8 and 9, coacting with a narrow angularly movable plate 42 carrying downwardly extending rods 47. The cross-beam 23, Fig. 5, has a housing 51 carrying two upwardly-extending rods 58 coaxially disposed with respect to the rods 47 when the grab is supported by the ring 28. In operation, assuming the grab to be open and supported on the ring there is a gap 47<1> between the ends of the rods 47, 58. On pulling in the hauling rope the gap 47<1> is closed and the rods take the vertical stress. Further hauling in raises the grab and the hooks 36 are detached by the angular extensions 41 bearing against the plate 42 and raising the sleeve 37. On lowering, the housing 51 drops, the rods are disengaged and the sleeve falls causing the extensions 41 to turn the plate 42 so that the rods are no longer in alignment. On hauling in, the rods 58 pass into recesses 60 in the thimble and the rods 47 pass through the cross-beam and the grab is closed. In a modification, one depending rod is used, the sleeve is replaced by a cut-away sliding block coacting with a pivoted arm carrying the rod which is aligned or disaligned with an aperture in the cross-beam housing as required. In another modification, the rod takes the form of an I-beam coacting with a similarly shaped aperture in the cross-beam housing.