GB2215225A - Toy - Google Patents

Abstract

A toy comprises an upright length to tube 1 of substantially uniform cross section containing a fluid, and a hollow member 4 which is slidable with clearance in the tube, which has a pair of chambers 5,6 one above the other and a constricted flow connection 7 therebetween, and which contains a charge of a substance 8 capable of flowing under gravity from one chamber to the other through the constriction. The substance may be particulate or liquid. In use, the tube is inverted (manually or by a motor) from its figure 1 position. The member 4 topples into frictional contact with the tube (Figure 2) until substance has flowed through constriction 7, whereupon member 4 rises up the tube. <IMAGE>

Description

Toy This invention relates to a toy.

According to the present invention there is provided a toy comprising a container which comprises an upright length of tube of substantially uniform cross section containing a fluid, and a hollow member which is slidable with clearance in the tube, which has a pair of chambers one above the other and a flow connection between the chambers having a constriction therein, and which contains a charge of a flowable substance capable of flowing under gravity from one chamber to the other through the constriction. At least one part of the tube should desirably be transparent. The tube can be of any suitable section, e.g. square, rectangular, elliptical, hexagonal or the like, but is conveniently circular in section. The length of tube is conveniently sealed at both ends. It may have a fluid reservoir at one or both ends. It may form part of a closed loop.

The fluid may be a gas but is more usually a liquid.

Non-toxic liquids such as water or liquid paraffin are preferred. A dye may be added to the liquid.

Particles, such as metallic glitter particles, may be suspended in the liquid.

The hollow member has a pair of chambers one above the other which are connected one to another via a constriction after the manner of an hour glass. The hollow member contains a charge of a flowable substance capable of flowing from one chamber to the other through the constriction, for example a charge of discrete particles or a charge of a liquid such as glycerin or mercury. Any suitable form of discrete particles can be used such as sand, glass balls, metal ball bearings and the like. The quantity of discrete particles or liquid to be used in the hollow members should be sufficient to impart a slight positive or negative buoyancy to the hollow member when placed in the fluid. The hollow member is slidable in the tube with a clearance.The clearance should be sufficient to allow the hollow member to pass up or down the tube, when this is filled with fluid and the charge of particles or liquid is in the lower chamber of the hollow member over a reasonable period of time, for example 5 seconds to 60 seconds.

The tube is conveniently made of glass, but it may be made of plastics. It may be protected by a metal, wooden or similar sheath having cut out portions to render the inside of the tube and the hollow member visible.

The hollow member may be made of a transparent or translucent material such as glass or plastics.

Alternatively, it may be made of an opaque material. It can have the shape of a medicine capsule or can be ellipsoidal.

It may have a waist corresponding to the constriction between the chambers. It may be shaped, for example, like a diabolo.

Whatever the shape of the hollow member it will generally be arranged to float with its major axis vertical.

Moreover its dimensions should be chosen so that it cannot invert within the length of tube when this is itself inverted.

In use, assuming that the toy is initially standing with the tube upright, the hollow member will lie at the top or the bottom of the tube, depending on whether it has positive or negative buoyancy, with its charge of particles or liquid in the lower chamber. Upon inverting the toy, the hollow member is initially trapped, at the other end of the tube from that to which it will tend to want to move by reason of its positive or negative buoyancy, with its charge of particles or liquid now in the upper chamber. The trapping arises because the centre of gravity of the hollow member is temporarily above its centre of buoyancy and so it topples against the walls of the tube.

The resulting frictional forces, if the clearance and the amount of buoyancy are suitably chosen, will suffice to prevent the hollow member from moving up or down the tube as its buoyancy dictates. Particles then flow, or liquid flows, through the constriction from the upper chamber to the lower, in the manner of an hour glass. In due course the centre of gravity will fall to, and then below, the centre of buoyancy, whereupon the hollow member will adopt an upright position, disengage from the walls of the tube, and move up or down the tube as its buoyancy dictates. The period that the hollow member apparently defies the buoyancy force will depend, inter alia, on the size of the constriction in relation to the size of the particles or to the viscosity and specific gravity of the liquid and upon how big is the charge of particles or liquid in the hollow member.Typically these factors are selected so that this period is from about 5 seconds to about 30 seconds, for example from about 10 seconds to about 15 seconds.

Although it is amusing and instructive to use a transparent hollow member, the toy can be rendered more puzzling to an onlooker by using an opaque hollow member and then inviting him to explain the movement of the hollow member since, as the clearance may permit only a small tilting of the hollow member, for example tilting through an angle of about 20 or less from vertical, this tilting movement may not be immediately apparent to the observer.

In order that the invention may be clearly understood and readily carried into effect a preferred form of toy constructed according to the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a view of the toy in its equilibrium position; Figure 2 is a view of the toy immediately after it has been inverted from the equilibrium position of Figure 1; and Figure 3 is a view of the toy, as it will appear a short time after inversion, as the hollow member floats up the tube.

Referring to the drawings, the toy consists of a length of glass tube 1 of circular cross section sealed at its ends 2 and 3 and filled with water. Within tube 1 is a hollow member 4 which has a pair of chambers 5 and 6 connected one to another via a constriction (the size of which is exaggerated in the drawings) and containing a charge of sand 8, after the manner of an hour glass. The charge of sand 8 is sufficient to give the hollow member 4 a slight positive buoyancy in water. The hollow member 4 thus floats in the water in tube 1, as shown in Figure 1, with a slight clearance (which is exaggerated in the drawings) with its centre of gravity G1 below its centre of buoyancy Go.

The gravitational force F1 is less than the buoyancy force Fo and so the hollow member floats freely. The clearance between hollow member 4 and the wall of tube 1 may be, for example, from about lmm to about 3mm, typically about 2mm.

Upon inverting the tube 1 to the position shown in Figure 2, the sand 8 is initially trapped in the chamber 6 which is now uppermost. This results temporarily in the centre of gravity G1 lying above the centre of buoyancy Go with the result that the hollow member 4 is in unstable equilibrium so that it topples slightly and engages the walls of the tube 1. The resulting frictional forces F2 and the gravitational force F1 exceed the buoyancy force F,, thus preventing the hollow member t from floating up the tube 1.As the sand 8 flows through constriction 7 into the now lowermost chamber 5, the centre of gravity G1 gradually falls and then passes through, and finally falls below, the centre of buoyancy Go As a result the hollow member 4 reverts to its upright floating position, disengages from the wall of the tube 1 and floats up the tube, as shown in Figure 3.

In the illustrated embodiment the hollow member 4 and its charge of sand 8 have a slight positive buoyancy.

The amount of sand 8 should be selected in relation to the volume of the hollow member 3 and the clearance between hollow member 4 and the walls of tube 1 such that it takes an appreciable time to float up tube 1, for example from about 5 seconds to about 60 seconds, preferably from about 5 seconds to about 20 seconds. Moreover the amount of sand 8 and the size of the constriction 7 in relation to the average particle size of the sand are selected so that the period during which the hollow member 4 apparently defies the buoyancy force Fo and stays at the bottom of tube 1 is from about 5 seconds to about 30 seconds, for example from about 10 seconds to about 15 seconds.

It is alternatively possible to increase the charge of sand 8 so that the hollow member 4 has a slight negative buoyancy. In this case the equilibrium position of hollow member 4 is at the bottom of tube i and, upon inversion, it becomes trapped at the top of the tube for a time before descending back to its equilibrium position after sufficient of the sand has flowed from the upper chamber back to the lower chamber.

The toy can be developed into a more elaborate form, in which an electric motor is made to invert the tube automatically periodically. This can be achieved by mounting the tube 1 in a rotatable holder driven by the motor. Periodic inversion of the tube 1 can be accomplished either by incorporation of a suitable timing delay or by positioning a photo-electric cell and a light beam so that the beam of light is broken by the hollow member 4 as it returns to its equilibrium position, whereupon the photo-electric cell activates the motor circuit to invert the tube 1 and repeat the operation.

As illustrated, the hollow member 4 is shaped externally like an hour glass; it can of course be made in any other suitable external shape, for example, shaped like a medicine capsule, so that if hollow member 4 is made of opaque material, the constriction is not visible and the principle upon which the toy operates is not immediately apparent to a casual observer.

Instead of making tube 1 of circular cross section it can be of square, rectangular or hexagonal section.

In an alternative embodiment the charge of sand is replaced by a charge of mercury.

Claims (7)

1. A toy comprising a container which comprises an upright length of tube of substantially uniform cross section containing a fluid, and a hollow member which is slidable with clearance in the tube, which has a pair of chambers one above the other and a flow connection between the chambers having a constriction therein, and which contains a charge of a flowable substance capable of flowing under gravity from one chamber to the other through the constriction.

2. A toy according to claim 1, in which at least one part of the tube is transparent.

3. A toy according to claim 1 or claim 2, in which the tube is of substantially circular cross section.

4. A toy according to any one of claims 1 to 3, in which the fluid is water.

5. A toy according to any one of claims 1 to 4, in which the hollow member with its charge of flowable substance is arranged to have a slight positive buoyancy in the fluid.

6. A toy according to any one of claims 1 to 4, in which the hollow member with its charge of flowable substance is arranged to have a slight negative buoyancy in the fluid.

7. A toy according to any one of claims 1 to 6, in which the flowable substance comprises discrete particles.