GB2260411A - Anemometer - Google Patents

Abstract

A hand-held anomometer for use as an educational aid. The anemometer includes a guide 18 having a wind scale (32) (Fig 2) over which a collar 28 moves to provide an indication of wind velocity. The position of the collar 28 on the guide 18 is determined by a governor-like arrangement 30 which is caused to rotate at a speed dependent upon wind velocity. <IMAGE>

Description

Title - Anemometer The present invention relates to an anemometer more particularly an anemometer of simple form which can be used as an educational aid.

An anemometer measures the rate of flow of gases and can be used for example to measure wind velocity. The instrument consists of a light wheel carrying a plurality of specially shaped vanes or blades, air movement past these blades causing the wheel to rotate. The rate of rotation is measured by a counting mechanism which provides a reading of the wind velocity.

A common type of instrument consists of four hemispherical cups carried at the ends of four radial arms pivoted so as to be capable of rotation as a wheel in a horizontal plane. The speed of rotation is provided on a dial at the base of the instrument which is calibrated to read wind velocity directly.

In accordance with the present invention there is provided an anemometer comprising an elongate guide such as a tube having a wind velocity scale on an external surface, at least one cup operatively mounted in bearing means at one end of the guide for rotation in spaced relationship relative to the guide, a pair of levers for the or each cup, the levers being connected together at a weighted joint in the manner of a governor, the free end of one lever being pivotally connected to the bearing means, the free end of the other lever being pivotally connected to a collar slidably received on the guide for movement over the wind velocity scale.

In use, the wind rotates the cup or cups in known manner but as the wind velocity increases, the weighted joint moves outwardly, thus raising the collar over the wind velocity scale to reflect the increased wind velocity.

As an educational aid, a significant advantag'e of the instrument is that it may be hand held by a handle which is formed by an extension to the hollow tube.

If desired, the pivotal connection between the upper lever and its respective cup may be adjustable between radially inner and outer settings, the inner setting being used to measure wind velocities of say 10-15 miles per hour and the outer setting wind velocities of say 0-10 miles per hour.

The invention will now be described further hy way of example with reference to the accompanying drawings in which: Figure 1 is a diagrammatic perspective view of one embodiment of an anemometer in accordance with the invention, and Figure 2 is an exploded view of another embodiment of the invention which is similar to that shown in Figure 1.

Figure 1 shows a light wheel 10 mounted for rotation in a horizontal plane on a hollow tube 18 the lower end of which includes a handle 20 by means of which the anemometer can be held. The wheel consists of four spokes 12 at the outer ends of which respective caps 14 are fitted. The centre of the wheel includes a star shaped plastics moulding 16 which covers the mechanical connection between the spokes.

A pair of levers 22, 24 are provided for each cup 14. The upper end of the lever 22 is connected pivotally to the inner end of the spoke 12 whilst the lower end of the lever 24 is connected pivotally at 26 to a collar 28 received as a sliding fit on the tube 18. The inner adjacent ends of the levers 22, 24 are connected pivotally together at a knee joint (not shown in Figure 1) which is weighted by a weight 30.

In operation, the instrument is held by the handle 20 in the wind in an upright position as shown. The wheel is rotated by the wind at a speed determined by the wind velocity. The position of the collar 28 on the tube 18 provides an indication of the wind velocity. The collar moves over a graduated scale (not shown in Figure 1) and the position of the collar at any one time can be read off from the scale thus giving an instant wind velocity figure. Should the wind velocity increase, then so does the speed of rotation of the wheel 10. The increase in speed causes the weighted knee joint 30 to move generally radially outwardly, in the manner of a governor, thus lifting the collar 28 up the tube 18. When this upward movement comes to rest, the wind velocity can be read off the scale at a position adjacent the collar edge.

In Figure 2, the same reference numerals have been used to designate the same or similar parts to those of Figure 1.

In the embodiment of Figure 2, the hollow tube 18 and handle 20 are formed in two interfitting longitudinal parts and the scale which was not illustrated in Figure 1 is designated 32. A spindle 34 is rotatably mounted in the tube 18 in nylon bushes 32, 38. Each of the four spokes 12 of the wheel is connected to the upper end of the spindle for rotation therewith. The mounting of the spindle within the tube forms a bearing for rotation of the wheel 10.

In the embodiment of Figure 2 the upper end of the lever 22 is adjustable between inner and outer settings. Thus, the spoke 12 is of sheet-like form into which is formed a slotted aperture 40 having notches 42, 44 at either end. A pin 46 of the lever 22 is slidably received in the slotted aperture 40. The pin may be seated in either the inner notch 42 or the outer notch 44. When set in the inner notch 42 higher wind velocities for example in the range 10-15 miles per hour can be measured whereas when set in the outer notch 44 lower wind velocities for example in the range 0-10 miles per hour can be measured.

Claims (10)

1 An anemometer comprising an elongate guide such as a tube having a wind velocity scale on an external surface, at least one cup operatively mounted in bearing means at one end of the guide for rotation in spaced relationship relative to the guide, a pair of levers for the or each cup, the levers being connected together at a weighted joint in the manner of a governor, the free end of one lever being pivotally connected to the bearing means, the free end of the other lever being pivotally connected to a collar slidably received on the guide for movement over the wind velocity scale.

2 An anemometer as claimed in claim 1 in which the weighted joint is a knee joint, the weight of which is provided on the lever connected to the bearing means.

3 An anemometer as claimed in claim 1 or 2 in which a scale is provided on the guide over which the collar passes, in use, the position of the collar on the scale providing an indication of rate of gas flow, such as wind velocity.

4 An anemometer as claimed in claim 1, 2 or 3 including a handle by means of which the anemometer can be held is provided on the lower end of the guide.

5 An anemometer as claimed in claim 4 in which the handle is separate from the guide to which it is connected.

6 An anemometer as claimed in claim 1 or claim 3, 4 or 5 when appendant to claim 1 in which the bearing means includes a spindle rotatably mounted within the guide tube in bearings.

7 An anemometer as claimed in claim 1 or 6 or claims 3, 4 or

5 when appendant to claim 1 in which the free end of said one lever connected to the bearing means is adjustable to a radially outer position, in use, higher wind velocities such as in the range 10 to 15 m.p.h. being measured with said one lever set in an inner position and lower wind velocities such as in the range 0 to 10 m.p.h. with said one lever set in the outer position.

8 An anemometer as claimed in claim 7 in which the or each cup includes a spoke of sheet-like form having notches at either end of a slotted aperture into either one of which the end of said one lever is receivable.

9 An anemometer substantially as herein described with reference to and as illustrated in Figure 1 of the drawings.

10 An anemometer substantially as herein described with reference to and as illustrated in Figure 2 of the drawings.