Table edge fixing device of Jolly balance

Abstract

The invention discloses a table edge fixing device of a Jolly balance. The table edge fixing device comprises a table plate (1), screws (2), a support (3), a metal cylinder (13), a fastening screw (15), a cylinder (16) and a spherical shell assembly (18). A threaded hole is formed in the upper end surface of the support (3); the support (3) is fastened on the table plate (1) through the screws (2); the cylinder (16) is a hollow cylinder and internally processed into a spherical surface, the spherical shell assembly (18) is embedded into a spherical surface in the cylinder (16); the side face of the cylinder (16) is welded to the front end face of the support (3) in a direction that a cylinder opening faces upwards, the fastening screw (15) is installed in the middle of the front face of the cylinder (16), a metal cylinder (13) is inserted into a cylindrical hole in the spherical shell assembly (18) from the upper end, then the fastening screw (15) is screwed down, and the metal cylinder (13) is clamped and fixed. The table edge fixing device of the Jolly balance is convenient to measure and stable in work, and can greatly improve the measurement precision of the Jolly balance.

Description

technical field [0001] The invention relates to a physical experiment instrument, in particular to a tableside fixing device of a Jolly balance. Background technique [0002] Existing Jolie scales such as figure 1 As shown, when measuring the surface tension coefficient of the liquid, it is necessary to hang a spring and a small plane mirror on the upper end of the inner cylinder. The small plane mirror passes through the glass tube (without any contact friction with the glass tube) and then hangs a metal wire at the lower end, and the metal wire is immersed in the outer cylinder. In the liquid to be measured in the upper running water cylinder, a water receiving cylinder is installed on the outer cylinder at the lower end of the flowing water cylinder, and the operation hand wheel is installed at the bottom end of the outer cylinder at the lower end of the water receiving cylinder. The measuring mechanism forms a very long transmission chain, which requires Jolis The outer...

AI Technical Summary

Problems solved by technology

[0003] In the student experiment, if the device is placed on the table, and the inner cylinder pulls the spring upward to drive the metal wire to move upward, it is convenient to operate the handwheel, but it is very inconvenient to read, and it is often necessary to stand on a stool to see the position of the cursor The scale value, and the moment the handwheel is released in the existing Joli scale driven by the rope wheel, the inner cylinder will generally fall back a certain distance, and this distance is generally between 0.2-0.7mm, which will bring a certain error to the measurement; If the Joli scale is placed underground for measurement, the handwheel is very low. According to the measurement requirements, after the metal wire pulls up the liquid film, the inner cylinder must rise slowly and steadily. Breaking ahead of time, squatting on the ground and rotating the handwheel and observing the readings of the wire and vernier, it is difficult to maintain body balance, improper operating posture, it is difficult to operate the handwheel smoothly to make the inner cylinder rise steadily, and it is more likely to make operation errors and make the measurement fail

[0004] The application number is 201821632067.7, which discloses "an improved Joley scale", which uses a screw drive to replace the existing rope wheel transmission structure of the Joley scale, which solves the problem of unstable operation of the inner cylinder of the Joley scale. The measurement accuracy is low, it is easy to be damaged, etc., but the following problems still exist in practice:

[0005] "An improved Jolie's balance" such as figure 2 As shown, the distance required to move the inner cylinder upward is placed inside the outer cylinder, and the height of the outer cylinder required is higher than that of the original Jolis scale outer cylinder. It brings greater inconvenience and affects the measurement accuracy; the second is that the fixed bracket is located at the bottom of the Jolly scale, and the operating handle is located at the top of the Jolly scale. The shaking of the outer cylinder makes the metal wire break in advance when pulling the liquid film, which affects the measurement accuracy, so the device needs to be further improved and improved

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