Patent GB-772489-A (GB)
Title: Improvements in or relating to loading apparatus
IPC: E02F3/34
Filed: 1954-03-10
Abstract: 772,489. Shovelling machines. MEILLER, F.' X., MEILLER, F. X., and BARTL, H. [trading as MEILLER FAHRZEUG-UND MASCHINENFABRIK, F. X.]. March 10, 1954 [March 14, 1953; March 18, 1953], No. 6951/54. Class 68 (1).  In a shovelling machine having a vertically swinging arm to which a load-lifting arm is articulated about a horizontal axis, raising means for the arms is adapted, through a pivoted lever arrangement, first to raise the load-lifting arm through a limited angle without corresponding movement of the vertically swingable arm, after which it operates directly on the vertically swingable arm to raise both arms in unison until the load-lifting arm reaches a vertical position, lost-motion means being provided between the arms to allow further movement of the load-lifting arm beyond the vertical position, to produce downward tipping of the load. In one form, Fig. 2, a pair of load-lifting arms 5 carrying a bucket 6 is pivoted at 4 on the ends of a pair of vertically swingable arms 2 pivoted at 1 to the tractor. Arms 5 are each formed with an extension 7 connected by a link 12 composed of two relatively slidable parts adapted for limited lost motion to a second link 13 pivoted on the arm 2 so as to form a toggle. Fluid pressure cylinders 11 pivoted at each side of the tractor have their piston rods connected to the toggle joints 14. On operation of cylinders 11 each toggle is straightened lifting the arms 5 and bucket 6 relative to arms 2 until the toggle pivots 14 engage the arms 2 whereupon the arms 2 and 5 are raised together to just beyond the vertical position where the lost-motion connection allows arm 5 with the bucket to tilt under gravity further beyond the vertical to dump the load. In the Fig. 3 form the toggles are replaced by a bell crank 10, 15 on each arm 2, one crank arm being connected to the piston rod of cylinder 11, and the other crank arm through a link 8 including a pair of telescoping tubes adapted to give lost-motion to the extension 7 of arm 5. The operation is as in the previous form, arms 5 with bucket 6 being raised relative to arms 2 until crank arms 10 contact the arms 2 whereupon arms 2 and 5 are raised together to just beyond the vertical position where the lost-motion connection allows further tilting of arm 5 and bucket 6 to the dumping position. To enable return of the arms without power a compression spring 20 whose initial length is adjustable by a nut 21 on a screwed carrying rod 19 is arranged at each side of the tractor between a bracket on the tractor and a short arm 18 pivoted at 17 to the arm 2 and engageable with arm 2 just before reaching the vertical position. In order to allow loads to be transported by the machine with the bucket partly raised and without maintaining pressure in cylinders 11, a hook 24 is pivoted on each arm 5 and is movable into two positions in each of which it is held by a spring 26 urging an extension 25 of the hook against one of two stops (not shown). Two pins 27, 28 are so arranged on each arm 5 that, during raising of arms 5 pin 27 engages with the hook to lock each arm 5 in position relative to arm 2, but upon raising arms 2 to the vertical position pin 27 moves beyond the hook during tilting of arm 5, Fig. 7, engaging a cam edge of the hook to push it to its other position allowing arms 5 to be lowered relative to arms 2 on return of the latter. During such return movement pin 28 engages the opposite edge of the hook to push it back to the first position.