Patent GB-671714-A (GB)
Title: Improvements in and relating to the automatic sampling of granular or powdered materials
IPC: G01N1/20
Filed: 1950-01-24
Abstract: 671,714. Conveyers; shoots. MERCIER, D. C. C. Jan. 24, 1950. [March 25, 1949] No. 1835/50. Class 78 (i). [Also in Groups I, XVII and XVIII] In a sampling machine of the type in which samples are taken from a moving stream of material in a delivery shoot at predetermined intervals of time and transferred through a dispensing device to a succession of containers mounted at uniform spacing on an endless band or rotary conveyer which is actuated intermittently so as to bring a fresh container at said pre-determined intervals of time into register with said dispensing device, the dispensing device consists of a sample chamber actuated so as to be moved directly into the stream of material so as to collect a true sample cross-section of the material, and then withdrawn from the stream to a position in register with one of the containers. A pair of endless chains 1 situated in parallel horizontal planes and vertically one below the other have attached to them 24 containers 7 which are moved successively into register with a dispensing shoot 35 at the rate of, say, one per hour, to cover a twenty-four hour period. The containers are attached to the chains for quick detachment either by inserting them in a U-shaped frame 39 provided with circular retaining bands 41, in the case of glass or like containers, the frames being secured to the links of the chains 1 by straps 40, or, in the case e.g. of metal containers, pins 44 welded or secured to them are inserted in brackets 45 secured to or formed on the links of the chain. The mechanism for moving the containers and operating the dispensing device consists of an electromagnet 20, the armature of which is linked to a bell crank, one arm 17 of which, through a link 15 and lever 13, operates a pawl 14 co-operating with a ratchet wheel 12, while the other arm 18 operates through a linkage 24, 25, a rod 27. The rod 27 is attached at its remote end to an arm 31 pivoted at 32 within the delivery shoot 21. A box. 34, open at the bottom and on the side facing the oncoming material, is secured to arm 31 and is normally accommodated in a compartment at the top of the shoot 35 where it is protected from the oncoming material in the delivery shoot 21 by a plate 36 adjustably inclined by a screw 38. The ratchet wheel 12 is mounted on a shaft 10 journalled in a fixed bearing sleeve 11. A bevel gear 9 on the remote end of shaft 10 drives a similar bevel on a shaft 5 on which is mounted a driving wheel 3 for the chain 1. On the upper face of the periphery of wheel 3 are fixed pegs 29. In operation, an impulse is supplied to the electromagnet 20 by means of a time recording apparatus. At the commencement of the impulse the electromagnet is energized pulling its armature to the left, Fig. 5, and thus rotating the ratchet wheel 12 and pushing rod 27 to the right. This turns the driving wheel 3 until a stop 30 secured to link 15 is lowered into the path of one of the pegs 29, thus stopping the wheel with an empty container positioned under shoot 35. At the same time rod 27 moves the box 34 into the path of material in the shoot 21, thus filling it. On cessation of the impulse, the pawl 14 returns to engage a fresh tooth on the ratchet wheel and the box 34 is withdrawn into shoot 35 where the contents fall into the container. There are an odd number of pegs 29, the alternate ones of which are engaged by the stop 30 in successive movements.