GB2155157A - Helix ring devices and assemblies including them - Google Patents

Abstract

An assembly comprises a support 1 and a helix ring 2 comprising two spaced hoops 3,4 and a multiplicity of vanes which are deployed when the hoops relatively rotate. Release of the helix ring from its stressed closed state is controlled and the extent of opening of the vanes is positively defined or controlled. The assembly may be as a tail unit for a projectile, a wheel for a vehicle, or the propeller of a pump. <IMAGE>

Description

SPECIFICATION Helix ring devices and assemblies including them This invention relates to helix ring devices.

In our British Patent No. 2101280 we describe, as an automatic erector, a helix ring which comprises two spaced apart coaxial hoops and a multiplicity of helical members or vanes which extend from one hoop to the other, the helical members being adapted to be stressed on relative rotation of the hoops, and, on relaxation, to expand outwardly.

Such a device will be referred to herein as a helix ring. In the aforementioned patent we describe the construction and manufacture of such a device; for example the helix ring may be formed from a cylinder, the two hoops relatively rotated so as to force the helical members or vanes to expand, and the helix ring may be heat treated so that the expanded state is the natural unstressed state.The present invention utilises such a helix ring as defined above and reference should be made to our earlier patent for further details of the manner in which such a device may be made According to the invention an assembly comprises a support, a helix ring having one of its hoops fixed to or integral with the support and the other hoop relatively rotatable relative to the support, means for retaining the helix ring in a closed, stressed state and for releasing the helix ring so that it expands, and means for positively defining or controlling the extent of opening of the helix ring.

There follows a description of several examples of the invention, with reference to the accompanying drawings, in which: Figure 1 is a simplified illustration of one embodiment of the invention; Figure 2 is a section through part of the embodiment of Figure 1; Figure 3 is a simplified illustration of another embodiment of the invention; Figure 4 is a sectional view through part of the embodiment of Figure 3; Figure 5 is a schematic illustration of one use of the invention; and Figure 6 is a schematic illustration of another use of the invention.

In the assembly shown in Figure 1, a shaft 1 supports a helix ring 2 which comprises two spaced apart hoops 3 and 4 and a multiplicity of vanes 5.

For convenience only, the helix ring, which may be constituted as described in Patent No. 2101280, is shown in its open or expanded state. The hoop 3 may be secured to or integral with the shaft 1 and the hoop 4 is supported by a wheel 5. The helix ring is held closed by a pyrotechnically actuated retractor 6 including a pin which engages the wheel 5 and which is retracted to allow the wheel, and therewith the hoop 4, to rotate by virtue of the stored energy in the helix ring. The wheel 5 carries a stop pin 7 which engages a pin 8 fixed to the support 1. The pins define the open or deployed state of the helix ring by positively limiting the further rotation of the hoop 4 in the sense for expanding the helix ring.

Figure 2 shows that in this example there may be approximately 60 degrees of movement between the closed and open positions of the helix ring.

Figure 3 illustrates a second embodiment of the invention. This is generally similar to the assembly shown in Figures 1 and 2 but the arrangement of the support wheel for the hoop 4 is different. The hoop is supported on a wheel 9 which has an internal gear ring 10 engaged by a toothed control wheel 11 of which the rotation can be controlled by a unit 12 operable in any suitable manner. The helix ring is shown in its open or 'deployed' state; it may be allowed to close to a cylindrical form. In an alternative, the wheel 11 may have only one tooth, which can be disengaged from the gear ring 10 to allow the helix ring to open to a limit defined by stops as shown in Figures 1 and 2.

Various other methods may be employed for holding the helix ring in its closed position and for defining or controlling the open position. For example, the helix ring may be enclosed by a sleeve which is removed in any suitable way. Any open position up to the helix ring's free state may be obtained by a suitable retaining device on the moving end of the helix ring and means for stopping that device at the required position. The open position could be controlled by a tube engaged by the expanded helix ring. Preferably however the angular movement is controlled by a stop on the moving hoop of the helix ring, as shown in Figures 1 and 2, or by means which permit controlled variation of the opening of the helix ring, as shown in Figures 3 and 4.

Each strip or vane of the helix ring is able to present an inclined surface to a fluid such as air or water moving in a direction parallel to the longitudinal axis of the helix ring. Accordingly the helix ring may be used to impart rotation to a body or be driven to impart movement to a fluid. The extent of these effects are dependent on the length of the vanes and the extent of relative rotation of the hoops at the ends of the helix ring. However, in order for the helix ring to perform satisfactorily in this manner, it is necessary to define or control positively the extent of opening movement of the helix ring.

Figure 5 illustrates one useful arrangement, comprising an elongate projectile 13 having a helix ring 2, including (but omitted from Figure 5 for simplicity) a suitable release mechanism and means for controlling or defining the open state. The helix ring constitutes a tail vane assembly for the projectile. The vanes of the helix ring both induce drag and cause the projectile to rotate in the airstream.

Thus the helix ring when deployed may constitute a stablising tail vane assembly for a projectile.

Figure 6 illustrates another arrangement, in which a shaft 1 and helix ring 2 as, for example, shown in Figures 1 and 2 are confined within a pipe 14. The shaft is rotated so as to cause the propeller constituted by the helix ring to produce a flow of fluid along the pipe.

Yet another alternative is to provide a vehicle with a plurality of wheels each of which is constituted by a helix ring, which may be released and deployed as previously described. This form of the invention exploits yet another feature of the helix ring, namely the ability of the vanes to form a wheel of which the rim is constituted by the outer periphery of the vanes.

The vanes need not be all the same; in particular they may expand to different diameters. Moreover, the hoops (which need not be entire) may be of different diameter so that the helix ring defines a frusto-cone when closed.

Claims (5)

1. An assembly comprising a support, a helix ring having one of its hoops fixed to or integral with the support and the other hoops relatively rotatable relative to the support, means for retaining the helix ring in a closed, stressed state and for releasing the helix ring so that it expands, and means for positively defining or controlling the extent of opening of the helix ring.

2. An assembly according to claim 1 in which the said means for controtling is arranged to provide positive variation in the angular position of the said other hoop.

3. An assembly according to claim 1 in which the said means for defining the extent of opening comprises a stop moveable with the said other hoop.

4. A projectile including a stabilising tail vane assembly including a helix ring according to any foregoing claim.

5. A vehicle including at least one assembly according to any of claims 1-3, the helix ring being arranged and deployable to constitute a ground engaging wheel for the vehicle.