JPH1026502A - Measuring device for diameter of circularly curved wall surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a measuring device by which the diameter of even a partial circle and a concave part can be measured even in a place in which a foothold is bad such as a cirecularly curved part at a building, a large-diameter pipe, a tree or the like by a structure wherein equal-length protrusions whose tip is at an acute angle are formed at both ends of the body, a groove for sliding along the central axis of a T-shaped body is formed and a scale sliding ruler is inserted. SOLUTION: A measuring device has a structure wherein equal-length protrusion 2 whose tip is at an acute angle are formed in positions which are symmetric from the center of a body 1 on both sides of the body 1, a groove 3 for sliding of a sliding ruler 4 is formed along the central axis of the body 1 and the sliding ruler 4 on which a scale has been engraved is inserted into the groove 3. In a measurement, the body 1 is held horizontally on a circularly curved wall surface at a structure such as a building, a breast wall or a cylindrical surface at a large-diameter tank, a silo or a tree, the right and left protrusions 2 and the sliding rule 4 are slid, and their to parts are pressed. At this time, since the right and left protrusions are fixed at an equal distance from the central axis of the body 1 and their lengths are equal, the tip of the sliding suler 4 hits the intermediate point of an arc connecting the to parts of the protrusions 2, and the sliding ruler 4 is directed to the center of a circle. The curvature (the diameter) of the arc can be computed on the basis of the vertex distance of the arc with reference to a chord.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention determines the positions of three points on the circumference of a curved surface portion of a structure such as a building or a wall and the diameter (radius) of a large-diameter pipe or tree, and defines a chord and an arc. The present invention relates to a device for measuring the diameter of a curved wall, which can be easily obtained from the separation distance.

[0002]

2. Description of the Related Art Conventionally, the circumference has been measured by a tape measure to perform back calculation, or the both sides of a pipe have been pressed by a measuring instrument having a vernier caliper to measure the distance between the arms.

[0003]

This has the following disadvantages. (A) Vernier calipers can measure only up to a maximum diameter of about 1.5 m. (B) A tape measure can measure up to a maximum diameter of about 30 m, but is 3 to 10
About the number of people is necessary. (C) Measurement is not possible at places with poor scaffolding, semi-circles, partial circles and concave surfaces. The present invention has been made to eliminate these disadvantages.

[0004]

The T-shaped main body (1) is provided with equal-length projections (2) each having an acute angle at both ends thereof, and slides along a central axis of the main body (1). )
Insert a slide (4) with a sharp tip, and then slide (4)
A curved wall diameter measuring instrument with a scale (5) engraved on it.

[0005]

Embodiments of the present invention will be described below. (A) On both sides of the main body (1), projections (2) of the same length are provided at the same positions from the center of the main body (1), the tips of which are acute angles. (B) A groove (3) is provided for the slide (4) to slide back and forth along the central axis of the main body (1). (C) Engrave the scale (5) on the slide (4). (D) Insert the slide (4) into the groove (3) of the main body (1) and incorporate it. The present invention has the above-mentioned structure. When this is used, the main body (1) is mounted on a circular curved wall surface of a structure such as a building or a retaining wall or a cylindrical surface of a large-diameter tank, silo, tree or the like. Hold horizontally and press the left and right protrusions (2). Next, the slide (4) is slid and the tip is pressed. At this time, the left and right protrusions are fixed equidistant from the center axis of the main body (1),
Also, since they are of equal length, the tip of the slide (4) always hits the middle point (apex) of the circumference (arc) connecting the tips of the left and right projections (2) and faces the center of the circle. The distance (M) between the vertices of the arc with respect to the straight line (string) connecting the tips of the left and right projections (2) can be obtained by reading the scale (5) of the slide scale (4). From the ratio, the curvature (diameter) of the arc is calculated secondarily using a simple general formula. As a specific example, if the interval between the left and right protrusions (2) is 40 cm,
The value of the bending radius (R) is R = 20,000 / M + M / 2
And the diameter (radius) is determined using only the separation distance (M). Prepare the quick reference table (6) according to the left and right protrusions (2) in advance and affix it to the body (1),
If printed, the diameter (radius) can be obtained immediately by comparing the numerical value of the scale (5) with the quick reference table (6).
Practicality increases further.

[0006]

【The invention's effect】

(B) Measurement can be made without discrimination between full circle, semicircle, partial circle, and sphere. (B) The diameter (radius) can be easily measured by measuring only one point alone even in a place with a poor footing. Also, it is not affected by the shape of the convex and concave portions. (C) A wide range can be measured from the number of diameters + cm to about 40 to 50 m. (D) It is very portable and excellent in mobility and operability.

[Brief description of the drawings]

FIG. 1 is a perspective view of the present invention.

FIG. 2 is a combined perspective view of the present invention.

FIG. 3 is an implementation diagram of the present description.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Projection 4 Sliding scale 5 Scale 6 Quick reference table 7 Structure wall

[Procedure amendment]

[Submission date] December 12, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a perspective view of the present invention.

FIG. 2 is a combined perspective view of the present invention.

FIG. 3 is an implementation diagram of the present description and shows a use situation.

FIG. 4 is an embodiment of the present description, showing a state of use on a convex surface and a concave surface.

[Description of Signs] 1 Main body 2 Projection 4 Sliding scale 5 Scale 6 Quick reference table 7 Structure wall

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

Claims (1)

[Claims] 1. A T-shaped main body (1) is provided at both ends thereof with equal-length projections (2) each having an acute end, and a slide groove (3) provided along a central axis of the main body (1). A circular wall diameter measuring instrument in which a sliding scale (4) having a sharp tip is inserted, and a scale (5) is further cut on the sliding scale (4).