DE52767C - Dimension and drawing angles, particularly useful for recording the development figures of conical bodies - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The present invention relates to a device, preferably for use by sheet metal workers, which when recording the development of lateral surfaces of conical bodies, their horizontal sections circles or Parts of circular arcs or any closed ones composed of circular arcs and straight lines or open figures can be used.

Should z. B. the jacket of a simple conical tube (truncated cone, Fig. 1 of the accompanying drawing) are recorded in the development, it is necessary to determine the size of the radii cb and c α (Fig. 2).

The size of these radii is dependent on the diameters bb and aa of the pipe to be produced and on the angle of inclination α of the cone side, namely is

= sin α or radius cb =

bb

2 ■ cb
ι

sin α

α α

Radius approx =

2 sin a

With a given size of one of the two diameters α α or bb , it comes down to it

to know to

on, the coefficient

sin α

to find the correct radii c α and cb of the development figure for the specific taper.

To determine these coefficients without further trigonometric or geometric calculations Construction, which are mostly unknown to the craftsmen and workers, the present instrument is used by for the most varied angles of inclination α the value

-: can be read.

sin α

The instrument consists of a bevel with a fixed and a movable leg, which the latter can ^{be adjusted within the limits of ο to 90 0} compared to the first at any angle. Both legs are connected by a segment arch provided with a scale, in such a way that when the movable leg is adjusted, the arch is pushed through under a mark on the fixed leg.

The scale on the segment arc corresponds to the division of the right angle into one any number of parts, with each

Partial line of value. of the expression - _;

sin α

for the associated position of the movable angle leg, d. H. for the related The size of the angle of inclination α is given by a ratio number. This ratio is easy to read from the mark on the fixed leg and half of it The value of the given diameter to be multiplied by the corresponding radius for to get the developed lateral surface figure.

On the accompanying drawing is shown in Fig. 1 a

and FIG. 2 a shows the instrument in two different embodiments, namely Fig. Ι a suitable for measuring at re-entrant angles, Fig. 2a that for Apply to raised angles.

In both figures, L denotes a ruler serving as the handle of the instrument, at one end of which the two ^{angled legs} / 1 Ύ are attached. Leg Z is the fixed one; the same is in the first embodiment (Fig. ia) at right angles to the ruler L, while in Fig. 2a it forms an offset extension of the ruler. The leg Z ¹ is connected to the ruler by a hinge, so that it changes its position in relation to the fixed leg by rotating around the hinge; it carries after the free end to the segment arc S with the scale. When the leg Z ¹ moves, the segment arc 5 slides under the guide plate m on the fixed leg, the straight part of the front edge of m serving as a mark for reading the ratio from the scale, s is a bent or soldered edge of the segment arc , which by stopping the guide plate m a rotation of the leg Z ¹ over 90 ⁰ addition BEZW. a complete pulling out of the segment arc from its leadership prevented.

The scale drawn on arc S corresponds to a division of the right angle into 16 parts. The two end positions of the movable leg (for a = o ° and α = 90 ⁰ ) are by stopping the leg Z ¹ and Z respectively. the nose s is fixed to the plate m , and there is no division on the arch for these positions. These two borderline positions, which form a cylindrical body or part of it, respectively. assuming a flat figure, the

Coefficient - = = 00, i.e. H. aerad-

sin α ο ~~

linear limitation of the development figure and

-; = ' = i, d. H. Processing the same

sin α ι '^{& 5}

given figure, must be preserved and are therefore irrelevant in practice.

Accordingly, on the division of the arc 5, only the 14 intermediate parts are indicated by lines, and each partial line is appended with its proportional number corresponding to the associated angle of inclination α.

In order to obtain simple values for the coefficients with such fractions, which are familiar to every craftsman, the division is not carried out quite evenly, but is arranged in such a way that the series 1 - 1 Y ₁₀₀ - 1 for the various positions of the movable angle leg ^] / ₅₀ - 1 ¹ J ₂₁ ^l / 12 ^: / β ^Λ / ίο '/ 10 ■ / 10' / 10

- ¹ V ₁₀ -2 ¹ A ₀ - ² Vi ₀ -3 ¹ A- 5 - 10 - 00

arises.

The division into 16 parts is chosen because this is the case for most cases Practice is sufficient. - Of course, a different division and gradation would also be used can be taken without sacrificing the essence of the instrument and the invention to change something.

Fig. 3a shows the two embodiments for application to re-entrant and raised angles combined on a common ruler L ¹ . Otherwise, the same letters designate the same parts of the instrument as in Figs. Ia and 2a.

The method of application of the instrument is as follows:

If a cone jacket (Fig. 1 and 2) or a part of such a jacket is to be recorded in the development and a model is available for this purpose in which the slope of the jacket can be measured most easily by a re-entrant angle (Fig. Ia), so first bring the ruler L into the plane of the boundary circle bb ' and then rotate the leg Z ¹ until it rests on the side surface of the model. Now you only have to the brand m the corresponding Verhältnifszahl, for example, i / ⁸ to read ₁₀ to get out

the Product i · _^8/10 the radius cb for

to get the unfolded figure. The radius c α can then be found directly by subtracting the side length b a. - If the inclination of the shell side can be measured more easily through the raised angle at α, then (Fig. 2a) the ruler L is brought into the plane of the boundary circle α α and again the SchenkerZ ^{1 is placed} on the model, reading the ratio number of the brand m and has

in the Product

a a

X ratio number the

Radius c α for the development figure. Radius cb can then be found by applying the length a b ..

If the mark falls between two division lines, the ratio can be determined by estimating determine with sufficient accuracy.

If there is no model of the object to be executed, the measuring instrument can be used apply to any figure represented by drawing with equal ease, wherein the scale of the drawing can be quite arbitrary.

For more complex bodies the present instrument is exactly the same. Way to use.

Should z. For example, the sheath of an oblique cone is recorded (Fig. 3 and 4), one first completes the figures Figure ^'2 a

to the straight cone α b ¹ δ ² α and proceed as described above. 'This results in the developed figure from ² b ¹ b ² a, Fig. 4. Then the distance bb ^{1 is} plotted on the (central b ' c and the curves W ¹ bb ^{2 are drawn} according to the measure of the eye.

In the same way, horizontal sections composed of curves and straight lines are created, FIGS. 5 and 7, the developments in FIGS. 6 and 8.

The lengths of the arcs bb respectively. aa in the development figures are to be determined by direct measurement or transfer with a compass (if a representation of the body to be produced is available in natural size).

Finally, a third embodiment of the instrument is shown, which is particularly suitable for carrying in the pocket, namely FIG. 9 shows the side view and FIG. 10 shows a view of the device for moving a pointer located under a cover plate. It denotes Z and Z ⁰ two side by side and a space between them, firmly connected legs, between which the leg Z ¹ can move freely; When folded, the three legs lie close to each other. On the middle leg Z ¹ , connected to the pivot point, a short lever χ is arranged, which carries a toothed rack y at its free end, which in turn engages with a toothed wheel n> provided with a pointer \ . This toothed wheel is mounted in the leg Z and a plate ν screwed onto the leg Z, so that this plate forms a closure for the lever x, the rack y and the wheels n> . The spring and the top of the cover plate ν, the scale S with the well-known graduation is attached to the constant grip between the rack and the toothed wheel , above which the pointer \ moves.

It should also be mentioned that this instrument can be used to measure angles from 90 to 180 degrees; however, it can just as easily be set up for angle measurements from ο to 90 °. For the transmission of the movement of the movable leg Z ^λ to the pointer ^ instead of the lever and rack connection, a pure gear ratio can also be used.

The use of this instrument is exactly the same as that of the instruments described above. The only difference from the former lies in the fact that the ruler is used for handling falls away and the scale is attached to a plate arranged on one leg so that the instrument can be easily carried in the pocket.

These instruments can also be used as a drawing angle for measuring and transferring all any inclination like an ordinary.

Claims (1)

Patent claim: A dimension and drawing angle for transferring any inclinations, as well as primarily for determining lengths when recording. of the development figures of conical bodies, consisting of an angle bevel with a fixed and a movable leg (I 1 ¹ J and an arc scale S, the division of which for any number of positions of the movable leg is relative numbers for the simple calculation of the development figures of conical bodies with whole or in part circular horizontal sections indicating the required radii. For this purpose ι sheet of drawings.