Patent GB-190613544-A (GB)
Title: Improvements relating to Weighing Machines.
Inventor: PARNALL THOMAS ST JULIAN BABIN
Filed: 1906-06-13
Granted: 1907-03-21
Abstract: 13,544. Parnall, T. St. J. B., and Hipkins, W. E. June 13. Steelyard apparatus.-Relates to modifications in the automatic steelyard weighing-apparatus described in Specification No. 4935, A.D. 1905, particularly to the means for controlling the poise - weight propelling - mechanism by the rise and fall of the steelyard. The poise e is propelled along the steelyard a by means of the screw f, mitre - wheels g, spur - wheels h, h<1>, k, o, and a falling weight p, or equivalent mechanism. The shaft i also carries a chainwheel j, clutch part l, and pulley m. A shaft r carries pulleys t, m<1>, and a loose sleeve r<1> upon which aTe mounted a chain-wheel j<1> and ratchetwheel u. An open chain 13 connects the chainwheels j, j<1>, and a crossed belt 14 the pulleys m, m<1>. A forked bracket v, Figs. 1 and 3, carries a lever w provided with a sliding weight w<2> on one arm, the other arm being forked to embrace the beam a, and also arranged to engage an arm x<1> on a spindle x when depressed. The free end of the steelyard a carries a projecting piece a<3> provided with a pin a<4> to actuate a balanced arm 1 pivoted at s<2> and provided with an adjusting-weight 4. A part of the arm 1 is connected to a ratchet pawl 6 by means of a pin-and-slot connexion, and also carries a pin 2 to engage the curved end of a spindle 8 which is acted upon by a spring 12 and carries an arm 11 to engage the poise e at the end of its travel. The parts occupy the positions shown when the mechanism is stationary. A load on the platform or weighbridge raises the free end of the steelyard, tilts the forked end of the lever w upwards, and, by means of the pin a<4>, raises the lever 1 and disengages the pawl 6 from the ratchet-wheel u, thus setting free the chain-wheel j<1> to rotate under the influence of the weight p. The rotation of the shaft i is transmitted to the screw f, thus moving the poise e along the steelyard. When the beam a balances again, the pin a<4> engages the bent arm of the lever 1 and causes the pawl 6 to engage the ratchet-wheel and arrest further motion of the weight p. When the load is removed from the platform, the free end of the beam a falls and moves downwards the forked end of the lever w, thus depressing the arm x<1>, rotating the shaft x, and moving the arm l<1> to bring the clutch sections l into gear. The pulley t, which is continuously belt or otherwise driven, then drives the shaft n through the parts r, m<1>, 14, m, i, k, o, and again raises the weight p for future use. When the poise e has almost reached its zero position, a projection e<1> engages a bell-crank lever z, and disengages the clutch parts l, and, simultaneously, the lower part of the poise engages the arm 11 and draws the shaft 8 to the left, to engage the pin 2 and withdraw the pawl 6 partly from the wheel u, so that a light load will operate the parts if necessary. The lever w may be arranged to engage the ratchet-wheel instead of, or in conjunction with, the balanced lever and pawl device. Counting, recording, or pointing mechanism may be connected by gearing to the shaft i as described in the prior Specification referred to.