Patent GB-509058-A (GB)
Title: Improvements in or relating to earth-moving apparatus
IPC: E02F3/64
Filed: 1938-02-11
Abstract: 509,058. Linkage load-handling machines. LAPLANT-CHOATE MANUFACTURING CO., Inc. Feb. 11, 1938, No. 4354. Convention date, Nov. 1, 1937. [Class 78 (iii)] [Also in Group XXI] Earth-moving apparatus comprises a frame with articulated portions, a bowl having longitudinally spaced points thereof movably connected to spaced points of said portions, and means for moving the bowl relatively to both said portions in accordance with relative movement between said portions. The machine frame comprises parts 14, 16 pivoted at 36 and supported on wheels 11, 18, part 16 having a detachable transverse bar 26 to which a following vehicle may be attached ; a hydraulic ram 42 effects relative pivoting of the parts 14, 16. A scraper bowl 61 is rearwardly connected to the part 16 by links 63 adjustable by turnbuckles 64 so that the bowl may be tilted transversely, the front of the bowl being connected by links 81 to the part 16 and by links 86 to extensions 88 of the part 14; the links 63, 81 may be parallel. The front of the bowl has arcuate edges and is adapted to be closed by a front apron 97 pivoted at 103 to plates 104 fixed to the bowl; the apron is moved by hydraulic rams 111. The bowl also has a movable rear wall 116 guided by rollers 122 in channels 76 on the bowl, the wall 116 being detachably connected to a hydraulic ram 131 adapted to advance the wall to empty the bowl ; transverse tilting of the wall 116 is prevented by cables 136, 137, Fig. 6, each secured at 139 to the front of the bowl and passing over pulleys 142, 144 on the wall to an anchorage 146 at the other side of the bowl. The hydraulic rams 42, 111, 131 are controlled by valves 174, Fig. 11, mounted in a block 169 carried by the frame part 14 and actuated through flexible shafts 201 and gearing by a common handle on a tractor hauling the machine ; the shafts 201 act through screws and splined nuts 209 to move the valves, while springs 219 acting between movable abutments 214, 221 always tend to maintain the valves in the mid-position shown. A central passage 227 in the valve block 169 gives equalization of pressure between the ends of the valves. The fluid supply is effected by a pump 157, Fig. 17, drawing from a reservoir 151 through a check valve 154 and supplying through a conduit 158 ; excess fluid passes to reservoirs 163, 164, for storage under air pressure, and when these are full, passes through a relief valve 161 to the reservoir 151. The conduit 158 leads to connected inlet passages 168 in the valve block and with the valves in the mid-position of Fig. 11, the fluid flows through passages 177 in the valves to connected outlets 184 and through a conduit 186 to the pump ; the outlets 184 are also connected through passages 196 to the inlet 168 of the next valve. Movement of a valve to the right in Fig. 11 closes outlet 184 and opens inlet 168 through port 187 to one end of the corresponding ram, white exhaust from the other end passes through ports 188, 192 to the reservoir. Movement of the valve to the left again closes outlet 184 and opens inlet 168 to port 188, while exhaust passes through ports 187, 227, 191 to the reservoir. In Fig. 19, the hydraulic ram 241 which controls emptying of the bowl is assisted at the beginning of its stroke by a short-stroke hydraulic ram 244.