Patent GB-190724390-A (GB)
Title: Improvements relating to Weighing Machines.
Inventor: GARRATT TOM PETTIFER
Filed: 1907-11-04
Granted: 1908-07-09
Abstract: 24,390. Garratt, T. P. Nov. 4. Automatic-feed weighers.-A machine for automatically weighing sugar, tea, and like materials comprises means for separating a portion of the material from the main supply, measuring by bulk an approximate weight of the material and making up the measured bulk to the required weight by means of the previously separated portion. The material is fed into an inclined shoot band passes over a sieve a, whereby the finer portions are separated and fall down a channel d into a small hopper e, while the bulk of the material passes into the main hopper c. In the hopper e, a mechanical stirrer f, rotated from the driving-shaft g, prevents clogging. The material flowing over the sieve a may be agitated by a plate provided with projecting prongs and reciprocated in any convenient manner. A rotating drum i is mounted beneath the hopper c, and is formed with a measuring-chamber j, the capacity of which may be adjusted by means of a movable base k. The drum is oscillated about its axis by means of a crank l on the driving-shaft and a connecting-rod m, and discharges the contents of the measuring-chamber into a scale-pan n carried by a counterbalanced beam o. During the oscillation of the drum, a cam q secured to the drum spindle r engages a roller s attached to a link p, and raises the link into a position to support the beam o while the material is being discharged into the pan. While the drum is discharging into the scale-pan, a dribble feed from the hopper e is in operation, and when the required weight of material is delivered into the pan the beam sinks and a projection t engages a switch v and completes the circuit of an electro-magnet u. The magnet withdraws a latch w from a lever x which is rotated by a weight y. A lever 2, supported by the lever x, drops when the lever is released, closing the cut-off gate 4, and preventing further supply to the pan. At the same time, the outer end x<1> of the beam strikes against a lever z and disconnects the catch holding up the pivoted base of the scale-pan, thus leaving the base free to drop under the weight of the material in the pan. After the material is discharged from the pan, the base is closed and locked by a counterweight. The other end of the lever x is slotted, and when the lever is released the slotted portion raises a bar 7 and permits a spring clutch 8 to connect the belt pulley 10 with the shaft g. This causes the drum i to rotate to the discharging position, and a stop 11 on the drum engages the weight y and raises the lever x to the original position. Simultaneously, the bar 7 is depressed and disengages the clutch when the belt pulley has made one complete revolution. The cover-plate 12 of the drum is pivoted and held in place by a spring 13, so that it can yield if the material in the measuring-chamber is in the form of hard lumps. The scale-pan is divided into two compartments by a fixed blade 15<b> and a hinged plate 14, in order to secure a uniform quantity of material in suspension between the cut-off gate and the pan when the gate closes. In the dribble compartment, distributing-guides 15 are mounted to break up the stream of material and distribute it uniformly. The plate 14 is connected to the lever z by linkage so that, when the base of the pan is unlocked, the plate 14 is moved and permits the dribble supply to discharge through the open base. An adjustable weight is attached to the beam to compensate for the amount of material in suspension between the cut-off gate and the pan the instant the beam is deflected.