SU896374A1 - Planimeter - Google Patents

Description

(54) PLANIMETER

I

The invention relates to a measurement technique and can be used to measure the areas of flat figures.

Devices for measuring flat figures (planimeters) are known, which contain articulated polar and bypass, a bypass pin located at the end of the bypass lever, and an integrating mechanism, made in the form of a roller with a rounded rimmed rim and a rotation angle counter polar | tJ.

However, this device is characterized by the complexity of the integrating mechanism and inadequate accuracy due to the roller slipping during its rolling.

Closest to the present invention is a planimeter comprising a base, a bypass lever with a dowel pin, a hinge bypass lever, and an offset mechanism made in the form of a measuring roller with an axis of rotation perpendicular to the shoulder of the bypass lever and a pointed rim that guides

measuring roller, parallel to the axis of its rotation and the scale of relative intersection of roller 2.

The disadvantages of such planimeters are the considerable size caused by the placement of the reading mechanism outside the measured field, and the lack of accuracy caused by the error in the kinematic scheme of the device (theoretical error).

ten

The purpose of the invention is to reduce the size and increase the accuracy of the device.

The goal is achieved by the fact that the suspension of the bypass lever is made in the form of a polar lever pivotally connected with

"5 by-passes at the point of intersection of the shoulder of the by-pass lever with the axis of rotation of the measuring roller.

In addition, the bypass lever is equipped with

20 by three bearing pads, the measuring roller guide is made in the form of a tensioned string, and the measuring roller is placed in the carriage installed

rotatable and moving along the string.

The drawing shows a planimeter, a general view.

The planimeter contains a polar lever I, pivotally connected with a base 2 and a bypass beam 3, a bypass piston (vair) 4 fixed to the end of the bypass lever 3, and a handle 5 for easy movement of the bypass bar, measuring roller 6 with a pointed o6ot , the carriage 7 of the measuring roller, the guide 8 of the measuring carriage, made in the form of a tensioned string and the scale 9 of the relative movement of the measuring roller. The bypass lever is provided with three U12 support sites, which ensure its basing on the object being measured, the carriage 7 of the measuring roller 6 is made movable along the guide 8 and rotatable around it, the axis of rotation of the measuring roller 6 is perpendicular to the shoulder AV of the bypass lever 3 (straight through the centers of the sight and the hinge connecting the bypass lever to the polar) and passing through the center of the said hinge.

Planimeter works as follows.

The base 2 is fixed outside the circuit to be measured, the bypass pin (reticle) 4 is set to the starting point, and a readout is marked on the scale 9. Then the closed loop is bypassed in the selected direction (for example, clockwise), while bypassing the bypass lever 3 with 1O pads -12 rests on the plane of the object being monitored, and the measuring roller 6 is pressed against it only by the action of its own weight and the unbalanced part of the weight of the carriage 7. The pointed rim of the roller 3 prevents slipping in the direction perpendicular to the shoulder aqueous lever and the carriage circuit GPI periphery of the measuring roller is moved along the guide. After the end of the contour of the coitur (arrival at the starting point), the second reading on the scale is noted. The area measured is equal to the product of the length of the shoulder AB of the bypass lever and the difference in readings on a scale of 9.

If it is necessary to increase the shushadi from the previously measured (for example

the areas of the auxiliary closed circuits located inside the main), the subtracted areas are walked in the opposite direction (counterclockwise).

The planimeter does not have a theoretical error, and the constancy of the force that presses the measuring roller to the object being monitored and the easy mobility of the roller carriage along the string provide high accuracy of measurement. The implementation of the suspension of the by-pass polar arm in the form of a polar lever allows one to reduce the dimensions both by reducing the length of the bypass arm and by placing the reading mechanism within the measured field.

Claims (2)

1. Planner containing base, bypass lever with bypass shift, a bypass lever suspension and a readout mechanism, made in the form of a measuring roller with an axis of rotation, perpendicular to the shoulder of the bypass lever, and a pointed rim that guides the measuring roller parallel to its axis of rotation, and scales of relative movement of the roller, characterized in that, in order to reduce dimensions and increase of accuracy; the suspension of the bypass lever is made in the form of a polar lever pivotally connected to the bypass at the point of intersection of the bypass lever with the axis of rotation of the measuring roller. 2, a planimeter according to claim I, characterized in that the bypass lever is provided with three bearing pads, the measuring roller guide is made in the form of a tensioned string, and the measuring roller is placed in the carriage mounted for rotation and movement along the string. Sources of information taken into account in the examination 1. Kozhevnikov S. N. and others. Mechanisms. M., Mechanical Engineering, 1976, p. 6О4605, Fig. 10.57. 2. In the same place 05-606, fig. 10.58 (prototype).