Patent GB-229126-A (GB)
Title: Improvements in or relating to mine shovels
IPC: E02F9/02
Filed: 1924-03-24
Abstract: 229,126. Butler, R. S. March 24, 1924. Scoop-arm machines comprise a support, a pair of reciprocating rods mounted thereon, means to reciprocate the rods independently of one another or in unison, and a pivoted shovel mounted on the end of one of said reciprocating rods to control forward and rearward movement of the shovel, the other reciprocating rod being connected to the said shovel to swing the latter on its pivot. As shown in Figs. 4 and 7, the upper frame is mounted on a turntable on the base 1, the turntable comprising an upper and lower ring 6, 7 secured to one another by bolts 9. The base 1 carries a ring gear 17 meshing with a pinion 21 which is rotated by a pinion 22 from the cylinders 31 of an oscillating engine, of which the piston rods 30 are pivoted to a crank 27 on the shaft of the said pinion 22. The cylinders 31 are pivoted on pins 32 and connected to a source of pressure comprising passages 38, 47, outlet pipe 48 and valve chests 51, 52, while eommunication to the cylinders is controlled by a handle 60 operating a plug valve, arranged in the valve chest 51, by means of a crank 55 and arm 57. The frame comprises members 61, 62 forming frames 63 provided with guides 64, 65, within which is arranged a bushing 68, Fig. 5, receiving a trunnion 69. A cylinder yoke 70 has a sleeve 71, which receives the trunnion 69 and supports the cylinder 74 which is provided with inner and outer pistons 75, 76 having tubular piston rods 77, 79. The piston rod 77 has a solid outer end 78 and receives a tube 81 provided with ports 90 to admit air between the pistons from a port 88 communicating with tube 81. A port 89 admits air to the cylinder behind the pistons by means of an opening, within which is arranged a cup-shaped member 91 having an opening communicating with the cylinder. A similar arrangement of cup-shaped member 107 in the outer cylinder head is provided, and comprises an opening 108 in the member, a spring 109 arranged to retain the member in the position shown in Fig. 4, and a plug 110 for receiving the end of the spring 109. The ports 88, 89 communicate with ports 96, 97 in the sleeve 71 which has an exhaust port 98. The trunnion 69 has an exhaust opening 99, communicating with opening 98, and openings 100, 101, communicating with openings 97, 96 in the sleeve. Another opening 102 in the trunnion communicates with a passage 103, pipe 104, and passage 106 in the outer cylinder head. A valve 111 arranged within the trunnion reciprocates and oscillates to connect the passages 88, 89, 104 to the fluid-pressure source, operation being effected by means of a link 116 and lever 120, Fig. 6. An inlet pipe 124 and hose 50 connect the valve to the fluidpressure passage 49 in the machine base. The piston rod 79 has a slot 126 receiving a pin 127 on the inner piston rod 77 and carries a collar 128 having ears 129, openings formed in which receive the pin 127. The collar 128 also has ears 130 receiving a pin 131 which are received in slots 132 in ears 133 on a yoke 134 which supports the dipper arms 140 secured to the side plates 141 of the dipper. The plates 141 have latches 143 to engage a latch bar 145 on the dipper lid 144 to hold it closed. The dipper lid is pivoted on pins 151 which engages holes in depending parts 154 of dipper arms 153 which extend the length of the machine and are pivoted to guide arms 162 provided with hubs 163 whereby they are pivoted on a shaft 164 in the frame 62. The arms 153 are connected by arms 155, mounted on the piston rod 79, and a collar 156. A pair of arms 168, formed on a hub 169 which is loosely mounted on the shaft 164, are pivoted to arms 170 which are in turn pivoted to the arms 153 at 171. Pivoted to arms 168 are rods 173 provided with pistons working in the cylinders 174 of dash-pots, the mechanism of which is pivoted to the base of the machine. A reservoir 175, communicating by passages 180 with each cylinder, is provided with valve mechanism comprising a valve 190 and spring 191 whereby the flow of oil between the reservoir 175 and the cylinders by way of passages 185 and chamber 183 is controlled. The valve is manually operated by levers 196 and 215, Fig. 4. The yoke 70 has depending arms 198 of which flat faces 200 engage lugs 201 to force the pistons 75, 76 outwardly when fluid is admitted thereto. Further, to prevent the bushing 68 from moving rearwardly when the parts are elevated for dumping, the frame 63 carries blocks 202 having curved faces 203 adapted to be engaged by extensions on the yoke. When the arms 153 are in extended position they are locked against rearward movement by flattened parts 208 thereon engaging spring-controlled latches 205, which are depressed by a link 211 and pedal 214 which also releases the oil from the dash-pots by pressing in the valve 190 above-mentioned. A cable 219 connected to the latch bar 145 and to a fixed bracket 220<1> releases the latch bar to empty the dipper. In operation, the valve 111 is rotated clockwise to connect the front of the cylinder with the exhaust port 98 and the passage 89 to the source of fluid, so moving both pistons and the dipper outwardly and swinging the guide arm 162 about the shaft 164 so that the levers 170 become semi-vertical. The pistons 173 are thereby raised and oil is sucked from reservoir 175 through valve 190 into the dash-pots 174, and also the faces 200 engage the lugs 201 and the bushings 68 move rearwardly. To swing the dipper on its pivot for digging, the valve 111 is moved inwardly to permit fluid to enter the passage 88 and thence into the space between the pistons to cause relative movement between them whereby the yoke 134 moves rearwardly..to swing the dipper arms 140. The valve is then moved counterclockwise to connect ports 88, 89 to exhaust port 98 and the front end of the cylinder to the source of fluid so that, the yoke 168 being locked against return by the dash-pots 174 and the arms 162 engaging the latches 205, the cylinder and dipper are swung into an elevated position, whereupon the cylinders 31 in the base are supplied with fluid to rotate the frame. Fluid is again admitted to the rear end of the cylinder 70 to force the dipper outwardly into a position over a car, the faces 203 preventing rearward movement of the bushings 68 and taking up the thrust. The cable 219, which has been pulled taut by the preceding operations, now exerts a pull on the latch bar 145 to free the dipper lid and discharge the contents by oscillating the dipper as in the digging operation. The parts are restored by admitting fluid to the outer end of the cylinder 70 and depressing the pedal 214 to free the latches 205 and unseat the valve 190. The cup-shaped members 91, 107 serve as cushions because the openings therein are closed by the pistons at the end of the stroke and entrap fluid in the end of the cylinder.