Patent GB-688284-A (GB)
Title: Improvements in or relating to apparatus for weighing articles in succession and indicating variations in the weights of the articles
IPC: G01G19/00
Filed: 1950-05-04
Abstract: 688,284. Mechanical relay and follow-up devices. MOLINS, D. W., and MOLINS MACHINE CO., Ltd. April 27, 1951 [May 4, 1950], No. 11090/50. Class 118 (ii). [Also in Groups VI, XVIII and XXXV] In a weighing mechanism adapted to control the rate at which tobacco is fed to a cigarette making machine in accordance with the weights of groups of cigarettes removed intermittently from the stream of completed cigarettes, movement of the weigh beam 1 about its fulcrum 2 is sensed by a mechanism comprising a bell-crank 6, 7, which intermittently is moved until its arm 7 contacts an abutment 4 on the beam, and a pair of feelers 10 which are then moved into engagement with a plate 9 on the arm 6 of the bell-crank; the degree of movement of the feelers permitted by plate 9 being used to control the tobacco feed rate. A shaft 64 carries a series of cams which effect the following timed cycle of operations: with the weigh pan 3 containing a weighed sample of cigarettes in compartments A, B the pan is rotated to discharge the cigarettes from compartment A, to flap 37 is then raised to divert a new sample of cigarettes to compartment C via rotating carriers 36, 39, the weigh beam takes up a position of rest corresponding to the weight of the cigarettes in compartments B, C, and a pair of clamp jaws 21 engage a member 19 secured to the beam. Next the bell-crank 6, 7 is freed to rotate anti-clockwise under the influence of a spring 11 until its arm 7 abuts against the stop 4, after which the feelers 10 are lowered. Should the sample be of the desired weight both feelers will abut against the plate 9 and no variation in the tobacco feed rate will result, but if the sample is over or under weight, one of the feelers will be moved beneath the level of the top edge of plate 9 and will operate an associated micro-switch 67 so energizing one of a pair of solenoids 68, Fig. 4, until after a predetermined interval of time, the feelers are again raised. Whereafter the bell-crank is pivoted out of engagement with abutment 4, the jaws 21 are opened, and the cycle is repeated. A continuously rotated eccentric 78, Fig. 4, oscillates a pair of pawls 73 adjacent a pair of ratchet wheels 79, and during the periods when both solenoids 68 are de-energized, a shaft 81, connected to the control member of a variable speed drive for the tobacco feeder (not shown) remains stationary, but on the closing of one of the microswitches 67 the associated solenoid 68 is energized and engages its associated pawl with the associated ratchet wheel and so effects rotation of shaft 81 in a direction dependent upon which of the ratchet wheels is driven. In a modification the plate 9 is stepped, and tilting switches are substituted for the micro switches, all as described in Specification 420,755, [Group VI], the feeler movement then being used to vary the tobacco feed rate in proportion to the movement of the feelers. Oscillation of the beam is damped bv the device in Specification 534,957, [Group XVIII], which comprises a copper coil 101 moving in a magnetic field.