Patent GB-674121-A (GB)
Title: Improvements in or relating to apparatus for delivering fluent discrete solid materials
IPC: B60P1/38
Filed: 1949-07-25
Abstract: 674,121. Unloading storage chambers from below; vehicle fittings etc.; hoppers. BARNETT, C., and BARNETT, W. Oct. 25, 1950. [July 25, 1949] No. 19563/49. Classes 78 (i) and 78 (iv). For discharging fluent discret solid materials from a hopper, the hopper is provided with a longitudinally movable false bottom which is driven so as to uncover gradually the underlying floor of the hopper and an endless band conveyer disposed between said false bottom antl said floor to receive material released by the movement of the false bottom, the conveyer being driven with its band moving faster than the false bottom so as to deliver the material through an outlet gate, at one end of the hopper The hopper 10 has an elongated bottom portion 11 mounted on a vehicle chassis 12 and having a discharge outlet 25. The bottom portion contains an endless scraper conveyer 14 which pushes material falling on to it along a plate 13 to the outlet 25. Around the endless scraper conveyer is a second endless member consisting of a flexible false bottom 15 composed of slats hinged together by roller chains and a pair of cables 41 each connected to both ends of the false bottom, this endless member being tensioned by adjusters in the cables. The false bottom when closed extends from a point adjacent the outlet 25 along a pair of guides above the scraper conveyer and around a driving sprocket 34 on a shaft 35 at the forward end of the hopper. Cables 41 pass under the scraper conveyer from the end of the false bottom adjacent sprocket 34 and around pulleys 43 to the other end of the false bottom. The space between the latter end of the false bottom rear wall 10 of the hopper is closed by a vertically sliding gate 18 which can be fixed at a desired elevation by a lever 20 pivoted at 22, Fig. 3, and adjustable with respect to a quadrant 23. The scraper conveyer is driven continuously with its conveying run moving towards outlet 25 by means of the rear sprocket 47, the drive including a clutch. The false bottom is driven more slowly with an intermittent, movement in the reverse direction the drive being taken from the shaft 48 of sprocket 47 by means of a crank 55, links 56, 57, Fig. 5a, and an oscillating pawl carrier 59 freely mounted on shaft 35 and driving through a reversible pawl 63, Fig. 5g, a ratchet wheel 62 on the shaft 35. Reversible pawl 63 is mounted on a shaft 64 between two plates 60, 61 comprising the pawl carrier 59, the shaft 64 projecting at both sides of the carrier. On the side 61 a short crank arm 67 is mounted and a spring 69 tends to turn this and the pawl from deadcentre position in which both dogs 65, 66 of the pawl are out of engagement with ratchet wheel 66. On side 60 a double arm crank 71. is mounted, having two pins 72, 73 engageable with an arcuate guide surface 84 of a sector plate 74, Fig. 5h, freely mounted on shaft 35. A hand lever 75 pivoted at 79 is coupled by links 76, 77 to sector plate 74 so that in its centred position in a quadrant 80, in which it is locked by a thumb-operated dog 82, the pawl is held out of engagement with the ratchet wheel by the guide surface 84. In its two extreme positions one of the pegs 72, 73 slips off one end of the guide surface 84 allowing dog 65 or 66 to engage the ratchet wheel and drive the false bottom in opening or closing direction respectively. Additional control is provided for automatica.lly stopping the drive to the false bottom when this is completely open on completion of the unloading. The control also automatically stops the false bottom in fully closed position after operation of lever 75 to drive it in the reverse direction. This control consists of two stop pegs 112, 113 each mounted on a lever 114 or 1 14a and engageable by a projection 111 fixed to the trailing end of the false bottom, levers 114, 114a being pivotally mounted near the two extremities of the movement of projection 111. Each lever is resiliently coupled by a spring 116 or 116a to a second pivoted lever 115 or 115a the two levers 115, 115a being interconnected by a link 121. A three-armed crank 98 which moves with lever 115 communicates the motions of the stops to links 99, 100 having slots 109, 110 in which slide pegs 95, 97 on the ends of a two arm crank 96. The latter is coupled by a link 94 to the linkage 76, 77 of hand lever 75. A spring 104 forces crank 98 into one of two extreme positions, which are changed either by movement of lever 75 into one of its extreme positions through the lostmotion connection 109, 110 or by engagement of the projection 111 with one of the pegs 112, 113. The control functions such that if lever 75 is moved into one of its extreme positions to cause movement of the false bottom to one end of its travel, the action of the projection 111 on the corresponding peg 112 or 113 causes lever 98 to snap into its other position to pull lever 75 back to its central position. The springs 118, 118a allow for the fact that if pawl 63 is is driving when projection 111 engages the corresponding abutment the lever 98 will not snap over until the end of said driving stroke, and forcing of the pawl is thus prevented. Wall 26 of the outlet 25 may be hinged upward for inspection. Sacks 300, Fig. 7, may be attached to the outlet 25 by pivoted grips 301. In a modification to give greater height for the sacks, Fig. 8, the scraper conveyer 14 is continued as an elevator 400 mounted on sprockets 402, 404, the former being the driving sprocket.