SU102616A1 - Scales with a mobile weight - Google Patents

Description

The subject of the invention is a scale with a movable weight, the measurement range of which can smoothly vary by the required amount.

Scales with a movable weight are known, which have a lever which senses a measurable force and is connected with a lead screw. As the screw rotates around its longitudinal axis, the measured force is balanced. A step change in the measurement range in these weights is achieved by adding calibrated counterweights.

The described scales are different from those known in that their lead screw can be rotated around a vertical axis, which ensures a stepless change in the measurement range.

The drawing shows a diagram of the scales.

The lead screw is connected with the lever / balance by means of a hinge. A finger is inserted into the end of the lead screw, which is inserted into the groove of the driver 3 by the lead screw 4. When the screw 4 is turned by the handle 5, the lead moves along it, and the angle between screw 2 and lever /. The movable gear 6 can be mounted on the screw 2 further away from or closer to the axis of rotation.

The balance is balanced by the counterweight 7 (the weight 6 and the load on the lever is removed) so that

The center of gravity of the system was on the ZZ axis.

The measured force P acts on the shoulder / o and creates a moment relative to the ZZ axis, balanced by the moment from the weight of the weight 6 on the shoulder /, -.

P / o - gf. The size of the shoulder 4 is determined by the position of the weight 6 on the lead screw 2 and the angle of rotation of the screw relative to the z axis ///.

From the drawing it is clear that

/.V / sin 9, where sin h - -;

since /.V And--, you can write

Pl or P x1-.

 through / C

If denoted /./o

then P Kx1.

X can be selected for the indication on the scale, and / - for the indicator of the price of division. In this case, the balancing process will consist in rotating the knob 5 of the screw 4 and moving the lead 3 along the screw with the fixed position of the load g selected.

According to the last formula, the readout on the x scale at the set value / gives the value measured from my load P.

Scales are expedient to use in cases when it is necessary to reduce the growth of relative measurement errors with decreasing effective load conditions, for example, in aerodynamic weights, the range of measured loads of which varies over wide limits.

Subject invention

Scales with a movable weight, containing a lever that can be measured and connected to a lead screw, which, when moving around its longitudinal axis, balances the measured force, distinguished by the fact that, in order to continuously change the scale value of the instrument and the range of its measurements, the lever is connected to the spindle with a pivot, new hinge, allowing us, to rotate the spindle around the vertical axis.