GB2198862A

GB2198862A - Time-measurement equipment

Info

Publication number: GB2198862A
Application number: GB08628035A
Authority: GB
Inventors: Shigeo Sato
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-11-24
Filing date: 1986-11-24
Publication date: 1988-06-22
Anticipated expiration: 2006-11-24
Also published as: JP2512701B2; JPS62123389A; DE3639602A1; FR2608796A1; GB2198862B; GB8628035D0

Abstract

A container 2 with orifice 1 is placed at distance H beneath the surface of a body of liquid 3. Bubbles 4, escape at isochronous intervals, and water correspondingly flows into the container in a regular fashion, causing float 8 to rise through the uniform horizontal internal cross-sectional area and thus operating rack 13 by rod 11, passing through-sliding seal 9. This turns pinion 14, whereby point 15 moves around dial 12 showing elapsed time. <IMAGE>

Description

TIME MEASUREMENT EQUIPMENT The present invention relates to a watch or clock especially suitable for measuring time in a humid atmosphere.

Time-measuring equipment presently in use utilises various kinds of isochronic events as a regulator or cause of onward progression of a display marked in units of elapsed time. However, few of them are suitable for use in a wet or humid environment.

The present invention however, is especially suitable for measuring time in such environments, and utilises as its isochron c counting event the outflow of successive air bubbles from an opening in a hollow container immersed in water or the like.

The present invention therefore sets out to provide time-measuring equipment comprising a container body in which can be contained a volume of air provided with an outlet opening in its wall through which air bubbles can flow- out and water in. In its simple embodiment the container can be constituted by a bottle or the like.

If such a container (an empty bottle for example) is held under water with said outlet opening upwards, the air contained inside the container comes out of the container through the outlet opening in the form of bubbles to rise upwards through the water which exists around and above the container, thereby permitting the water to flow into the container through the same outlet opening instead.

The escape of bubbles is both attractive and provides an isochronous series of events which can be used to cause or regulate the display of a timemeasuring instrument such as a clock or watch, in the same way as the swing of a pendulum can be used for such a purpose.

The invention accordingly consists in a method of measuring time in which the isochronously spaced escape of bubbles from an orifice in a hollow, otherwise closed,container located with the orifice at a predetermined depth below the surface of a liquid is used to cause, or regulate, the operation of a display showing elapsed time.

More specifically the invention consists in equipment for measuring time, comprising a hollow container with an air escape orifice and a un iform horizontal cross-sectional area; a float within the container; and means interconnecting the float and a display member: whereby when the container is placed under the surface of a liquid, with the orifice at a predetermined distance beneath the surface, air bubbles escape at isochronous intervals with ingress of a corresponding volume of liquid causing the float to rise and the interconnected display to change.

The invention will be further described with reference to the accompanying drawings in which: Figure 1 is a diagram of the essential feature of time-measuring equipment in accordance with the invention, and Figure 2 is a diagram of a practical embodiment of such time-measuring equipment.

In Figure 1, a container body 2 has an upper orifice 2, and is submer;ged in water (or the liquid) 3 so that the outlet plane of orifice 2 lies at depth H beneath the surface of the water, whereby bubbles 4 are formed, isochronically, as water runs into the container. These bubbles can be used to cause, or regulate, the display on a time-measuring instrument.

The period between formation of successive bubbles as water flows into the closed container is believed to relate to parameters such as the shape of the outlet, size of outlet, internal dimensions of outlet channel, friction coefficient, surface tension, and air pressure inside the container. We have found that for any distance H there is however isochronicity of bubble formation (and corresponding water inlet volume) since the other parameters are constant. With the same value of H over different measurement periods the isochronicity period is the same. Thus, the arrangement shown diagrammatic ally in Figure 1 can be used as the cause or regulation of a time-measurement display.

Figure 2 shows how a time-measurement instrument can be embodied, in that the isochronous bubble is measured by isochronous increments of liquid volume accumulating in the container and in that , in turn, this volume increase is measured as an increase in height of the liquid in the container by providing this with a constant horizontal internal cross-sectional area along its length.

The container body is again indicated at 2, the outlet at 1, the liquid at 3 and the bubbles at 4, originating at depth H. The container has an essentially uniform horizontal cross-section.

Within the container 2 a float 8 is connected via rod 11 through slidably sealed opening 9 to a rack 13, serving to rotate a pinion 14,provided with pointer 15 over display plate 12. Mechanical support members 5 for the container, and 10 for the display plate 12,are also provided. The container can be removed after a period of time-measurement and drained through port 7 fitted with drain valve 6.

The display plate 12 is marked, for example, with a 0-60 second display scale.

In practice we have found that bubble escape in such a device, watched in a strobe light,is very isochronous. In a series of runs under different conditions, a 60-second time period was always measured with accuracy oft 0.5 seconds, and occasionally with accuracy down to 0.05 seconds, which is fully adequate accuracy for such a device in a domestic situation.

In utilising the equipment as shown, the volume of the container should be a sufficiently small proportion of the total volume of water available that no significant relative diminution of depth H is observed over a period of use.

Claims

CLAIMS.

1. A method of measuring time in which the isochronously spaced escape of bubbles from an orifice in a hollow, otherwise closed,container located with the orifice at a predetermined depth below the surface of a liquid is used to cause, or regulate, the operation of a display showing elapsed time.

2. Equipment for measuring time, comprising a hollow container with an air escape orifice and a uniform horizontal cross-sectional area; a float .:thin the container; and means interconnecting the float to a display member: whereby when the container is placed under the surface of a liquid, with the orifice at a predetermined distance beneath the surface air bubbles escape at isochronous intervals with ingress of a corresponding volume of liquid causing the float to rise and the interconnected display to change.

3. Equipment as claimed in claim 2 in which the float is mechanically interconnected to a movable display member.

4. Equipment as claimed in claim 3 in which the float carries a vertical operating rod, sealingly slidable through the container wall and carrying a rack at its upper end to cooperate with a pinion operating a pointer rotary around a circular scale of elapsed time.

5. Equipment as claimed in claim 2, 3 or 4 in which a selectively openable and closable drain port is provided at the base of the container.

6. Equipment aS claimed in claim 2 and substantially as herein described with reference to Figure 2.