GB650618A - Improvements in or relating to scraper attachments for tractors - Google Patents

Abstract

650,618. Load-handling machines. FERGUSON, Inc., H. Jan. 26, 1948, No. 2248. Convention date, Jan. 4, 1947. [Class 78 (iii)] [Also in Group XXI] On the hydraulically adjusted draw-bars 21 of a tractor is pivotally mounted a U-shaped yoke 31, the lower and rearwardly inclined portions of the limbs of which are pivotally attached to a scoop 30 at a point 42 situated ahead of the centre of gravity of the scoop. The yoke is attached at its centre portion by a lost-motion connection 49 to a link 33a secured to a crank arm 15 mounted on the tractor so that, as the scoop is dragged through the ground the link 33a is kept in compression and, should this compression force on the link become excessive, a predetermined compression of the spring occurs causing operation of the hydraulic system so that the draft arms 21 are rotated about the pivots 22 and the scoop is lifted. When in normal use, the scoop is filled, the draft arms and scoop are raised and, owing to the C.G. of the scoop being to the rear of the point of suspension, it rotates until abutments 60 on the scoop engage lugs 61 of a locking device 32 pivotally mounted on the yoke so that the bucket is tilted slightly to the rear and thus spillage is prevented. The latch means is constrained to engage blocks 60 by a spring between the arms 63 and the side arms of the yoke. Associated with the top of the yoke are pivoted arms 70 the forward ends of which are slidably supported from the link 33a and which carry between them a pivoted hook 74. As the scoop is raised, the lost-motion connection rotates to stretch rearwardly so that the hook moves rearwardly of the member 33a to engage the cross bar of the latch. To trip the latch to allow the bucket to rotate and dump rearwardly, the draft arms are lowered sufficiently to allow some forward movement of the draft linkage which thus causes the hook to move forward and trip the latch. The scoop is reset by lowering the draft arms as the tractor moves forward so that the bucket which is in contact with the ground is rotated back into its original position. Pivoted member 85 on the yoke can be rotated from one side of a stop 87 to the other to permit engagement of the latch or not as desired. When it is desired to use the scoop for levelling purposes, the catch is released permitting it to swing backwards into the dump position and pivoted stop 82 mounted on the yoke is interposed between the yoke and the scoop to maintain it in position. The link 33a and the lostmotion connection may be released by a telescopic link. Specification 470,069, [Group XXXI], is referred to.