GB1073192A - Grapple construction - Google Patents

Abstract

1,073,192. Grapples. DROTT MANUFACTURING CORPORATION. June 8, 1964, No. 23619/64. Headings B8B and B8H. A grapple having a pair of depending lifting arms 140 pivoted at their ends to a frame section 101F to engage between them a load B wherein the arms 140 are adapted to swing transversely of the longitudinal axis of the frame section into the horizontal plane thereof to allow the grapple to pass over the load and wherein the arms engage and disengage the load under powered control. Each arm 140 is pivoted at 138 between flange plates 136 secured to a plate 128 on the end of the frame 101F and is biased into the outer load disengaging position by a pair of spring-loaded telescopic struts 151, 152, 153. The outward movement is adjustably limited by a screwed rod 157 pivoted to the plate 128 at 158 and passing through an opening 143 in the arm 140. Each arm is moved against the spring struts into the load engaging position by a cable 165 having one end anchored to the plate 128 and passing around a sheave 141 mounted in the arm 140. The cable 165 passes from the sheave 141 through a rotatably mounted tubular portion 122 of the frame 101F, over an upper pulley 167, around an equalizing sheave 176 (Fig. 7) and back on to a lower pulley 168 before passing through the other similar half of the frame 101F on to the other arm 140. Each of the tubular portions 122 is rotatably mounted in bearings 115, 121 and the plate 128 freely mounted on to the end of each portion 122 is rotatably driven therewith by a pin 133 engaging in an arcuate slot 134 in the plate 128 to effect a lost motion portion during the drive Rotation of the tubular portions 122 effects the raising of the arms 140 into the horizontal position. An hydraulic jack 193F in Fig. 7 is pivoted between one end 196 of a crank 182 and a pin 199 extending between two crank plates 191, 192 coupled to the tubes 122. The crank 182 is pivoted 183 to a structure 108, 186 extending from the frame 1O1F and has its remote end 181 pivoted to an adjustable rod 178 177 support ihg the equalizing sheave 176. The movement of the crank 182 is limited by an adjustable stop 203 and the movement of the tubes 122 is limited by adjustable stops 201, 202 engaging a lip 200 formed on each crank plate 191, 192. Expansion of the jack 193F causes the sheave 176 to move towards the pulleys 167, 168 whereupon the arms 140 move outwardly and further expansion causes rotation of the tubes 122 thus raising of the arms 140 into the horizontal plane. In the embodiment of Fig. 1 two of these grapples 101F and 101R are mounted in cross beams 65, 66 of a gantry and their distance apart is adjustable by means of telescopically engaging tubes 105, 106 extending from the structure 186 of the frames 101. Each grapple is freely mounted on chains 211 to a carriage 81 which is mounted on to the crossbeam 65 by wheels 82 for movement therealong. This movement is effected by a cable 86 passing around pulleys 87, 88 and driven by a drum 84F of an hydraulic winch 83F, 85F mounted in the beam. The cross beams 65, 66 are movable vertically on the gantry by cables 71, 72 passing over a pulley arrangement and being driven by an hydraulic winch 68F, 74. The gantry comprises front and rear arches adjustably connected by beams 17, 18, each arch being mounted on wheels. The wheels 34 of the front arch 13, 14, 15 are steerable by hydraulic jacks controlled from a valve 45. The front wheels 34 are driven by hydraulic motors 59L, 59R.