GB2071773A

GB2071773A - Wind Propelled Device

Info

Publication number: GB2071773A
Application number: GB7941488A
Authority: GB
Original assignee: LIU HAN CHENG; LIU THUNG CHI
Current assignee: LIU HAN CHENG; LIU THUNG CHI
Priority date: 1979-11-30
Filing date: 1979-11-30
Publication date: 1981-09-23

Abstract

The device has one or more collapsible frameworks mounted for rotation on a shaft 301, each framework comprising two frames formed by a plurality of pivoted members 302, 303, 304, 309-313 mounted on collars 308, 314 on opposite sides of the shaft 301. Parachutes (Fig. 7-1 not shown) are attached to the frames so that the canopy of each parachute is held on one frame whilst its control lines (e.g. 603, Fig. 6 not shown) are anchored to the next trailing frame in the direction of rotation of the device, so that as it rotates parachutes going off the wind fill and those coming into the wind collapse. <IMAGE>

Description

SPECIFICATION Wind Propelled Device This invention relates to a wind propelled device such as a windmill.

The recent energy crisis has drawn attantion to the fact that oil in the earth's crust is not exhaustible. The problem of energy shortage will become more and more serious in the future if we still rely on conventional fossil fuels as our major energy source so that the development of other available energy sources has become urgent.

There exists abundant energy in nature for us to exploit such as wind power, which has been used for centuries. However, conventional windmills of the propeller blade type which once prevailed in many areas of Europe are no longer regarded as important today as in the past in view of their structural defects. First their efficiency in converting wind power into available forms of energy is noticeably low because the wind direction is not always in accordance with the direction the propeller blades move and in consequence the resultant force on the blades is only a small portion of wind strength (see Figure 1). Moreover, the windmill always needs to face into the wind which, for many windmills, requires an operator to rotate the windmill abouts its base.

A device for exploiting wind power seen in Figure 2 is free of the need for an operator but its efficiency is still low because when one of the propellor blades (21 ) is propelled forward by the wind simultaneously another blade (22) is moving into the wind and undergoing resistance to the wind which thus reduces the rotational speed of the device and causes a noticeable loss in the exploitation of wind power. Also the above two devices have a structure which cannot be changed to adapt to varying wind strengths and this makes them vulnerable in voilent winds such as typhoons, hurricanes, or tornados.

In accordance with thisinvention therefore we provide a wind propelled device comprising a pair of frames, each frame extending radially from an axis of rotation in opposite directions so that said frames lie in the same plane; each frame having a parachute attached thereto.

Preferably each pair of frames comprises a collapsible framework and the parachutes are made of soft yet tension-resistant materials such as canvas, nylon cloth etc. An advantage in using parachutes is that they can be opened up when moving off the wind to offer a large windblown area and then closed down when moving into the wind to reduce drag to a minimum thereby increasing efficiency. The frames can be folded down like a music stand to avoid damage in unfavourable conditions and unfolded for normal operation.

In the accompanying drawings: Figure 1 is a simplified representation of a known propeller style windmill; Figure 2 is a simplified representation of another known form of wind propelled device used in anemometers; Figure 3 is a front view of a pair of frames forming a framework fully unfolded and a folded parachute in accordance with this inventicn; Figure 4 is a front view of a pair of frames folded downwards in the collapsed condition; Figure 5 is a plan view of a wind propelled device in accordance with the invention and comprising a plurality of frameworks disposed symmetrically about a shaft; Figure 6 is an isometric view of a wind propelled device in accordance with this invention showing the attachment of the parachutes to the frames which are themselves only part shown; Figure 7-1 shows a parachute opened out and laid flat;; Figure 7-2 shows the form of a closed parachute and a parachute shaft; and Figure 8 shows an embodiment using two frameworks each comprising a pair of frames, mounted on a shaft one above the other, the arrows indicating the direction of rotation of each framework.

The straight arrows in the above figures indicate the wind direction, while the curved arrows indicate the direction of rotation of the frameworks of the windmill.

The present invention relates to a wind propelled device which provides an efficient and economic way of exploiting wind power. In the preferred embodiments described herein with reference to the accompanying drawings, the device basically comprises one or more frameworks each comprising a pair of frames and attached to the frames a plurality of parachutes.

Figure 5 is a plan view of a wind propelled device in accordance wtih this invention comprising three frameworks symmetrically arranged around an axis of rotation provided by a shaft, each framework comprising a pair of frames, one pair being illustrated in Figure 3 with the canopies of each of the six parachutes being retained on respective frames and the control lines anchored to trailing frames.

The collapsible framework shown in Figure 3 comprises a pair of frames each having upper and lower parallel spaced apart rectangular section side members 302, 304 respectively, each pivoted at one end to respective collars 308 mounted on shaft 301 and an intermediate rectangular section member 303 which at one end is pivoted to another collar 308 mounted on the shaft 301 and at the other end is pivoted to and extends beyond two cross-members 310, 312. Further cross-members 309,311 are pivoted to the upper and lower side members 302, 304 respectively and to the intermediate member 303. Two arms 313 are pivoted to a collar 314 mounted on the shaft 301 below the collar 308 pivoted to the lower side members 304, to which are also pivoted the other end of the arms 31 3 at the connection with the cross members 311.Anchoring points 305 and 306 for the control lines of a parachute are provided on the bottom and top surfaces of upper and lower side members 302, 304 respectively and anchoring points 307 on the front surface of extended end portions of the intermodiate members 303. Fixing points 3031 are provided on the intermediate members 303 for a rod 707 having fixed holes 7071 therein (Figures 7-2) which is passed through a pocket formed by the sewn seams of two triangular panel portions forming part of the canopy of a parachute, the bases of the triangular panels being sewn to an equilateral panel portion 701 and an air vent aperture 705 provided at the intersection of the two sewn seams as shown in Figure 7-1.A ring 706 is sewn to the apex of the equilateral triangular panel and two rows of rings 703, 704 to the sides of the two triangular panels, all the panels being made of canvas or nylon cloth or some other suitably close woven material.

Preferably the two triangular panels are right angled.

Figure 6 shows a parachute attached by its rod 707 to one frame (only partly shown) with its control lines 603 reeved through the anchoring points 305 on the upper side member 302 of a trailing frame and its control lines 604 reeved through the anchoring points 306 on the lower side member 304 of that frame with a further control line 605 reeved through the anchoring point 307 on the intermediate member 303. The parachute on the left hand side of Figure 6 is filled with wind as indicated by the arrow whilst the parachute on the right hand side is collapsed as it is facing into the wind. The function of the control lines is to keep the parachute canopy in shape when receiving wind and to prevent it turning inside-out whilst the air vent aperture 605 prevents undue air turbulence or whirls forming.

Thus as the device rotates those parachutes coming into the wind collapse and those going off the wind fill, the collapsed parachutes reducing resistance to rotation of the device.

The collars 308 can either be fixed to the shaft 301 so that the shaft rotates with the frameworks or they can be rotatably mounted and maintained in predetermined axial positions on the shaft so that the frameworks rotate about the shaft 301 which is then fixed.

The pivoted construction of each frame and the provision of the pivoted arms 313 enables the framework to be collapsed, rather like a music stand, as shown in Figure 4. Since in a preferred embodiment all six frames are pivoted to the three collars 308, all the frames can be errected by pushing collar 314 (to which the respective arms 31 3 of all six frames are also pivoted) upwards so that the side members 302, 304 extend perpendicular to the shaft 301, the collar 314 may then either be locked to the shaft if the collars 308 are secured thereto or if they are not the collar 314 may be maintained in position by other means.

Two or more frameworks can be mounted one above the other at different angular orientations on the shaft 301 as shown in Figure 8.

Furthermore when rotatably mounting such frameworks about a fixed shaft one frame can rotate in a direction opposite to that of the other framework.

The device can be made in various sizes to adapt to different conditions and can use one framework having a pair of frames and two parachutes or a plurality of frameworks and parachutes, the frameworks being symmetrically' disposed about the shaft to provide a balanced construction.

Notwithstanding the high efficiency and practicality, the preferred embodiments disclosed herein are very economical because the construction requires few parts that makes the cost of production cheap. Also the device is easy to erect and dismember which facilitates its conveyance from one plane to another thereby reducing transport costs.

It can be made in different sizes and used in many applications. It can be small for use with a miniature generator to provide power for a small family dwelling or can be scaled up to a windpowered plant for a whole community.

Should any of the parachutes become damaged they may easily be replaced by removing the rod 707 together with the parachute from the intermediate member 303, taking the damaged parachute canopy off the rod 707 and then threading it through the aperture 705 and the elongate tubular pocket formed by the sewn seams of the two triangular panels of a new canopy. The rod together with the new canopy can then be re-attached to the intermediate member 303.

Claims

1. A wind propelled device comprising a pair of frames, each frame extending radially from an axis of rotation in opposite directions so that said frames lie in the same plane; each frame having a parachute attached thereto.

2. A device as claimed in Claim 1, including a shaft mounting a plurality of collars and whose axis forms said axis of rotation, wherein each frame includes parallel spaced apart side members each pivoted at one end thereof to a different collar and one or more cross-members between and pivoted to said side members so that said frame can be moved from a first position at which said side members extend perpendicular to said shaft to a second position toward said shaft.

3. A device as claimed in Claim 2, including a ; further collar slidably mounted on said shárl and having arms, one end of each arm being pivoted on opposite sides of the collar, the other ends being pivoted to the side members so that both frames of a pair move in unison between said first and second positions.

4. A device as claimed in Claim 3, wherein each said frame comprises two side members and a member intermediate and parallei thereto with cross-members between said side members, one pair of cross-members forming a third side to a frame and a second pair of cross-members located between saidthird side and said shaft, all the cross-members being pivoted to their respective side members to allow said frame to move from said first and said second position.

5. A device as claimed in Claims 2, 3 or 4, wherein the collars to which said frame members are pivoted are secured to said shaft.

6. A device as claimed in Claims 2, 3 or 4, wherein the collars to which said frame members are pivoted are rotatably mounted on said shaft and retained along said shaft at predetermined positions.

7. A device as claimed in any one of the preceding claims, including a plurality of pairs of frames symmetrically mounted about said axis.

8. A device as claimed in any one of the preceding claims, wherein the canopy of each parachute has an aperture therein, each parachute having a rod passing through said aperture and extending to the edge of the canopy, the opposite ends of the rod being secured to the intermediate member of a frame.

9. A device as claimed in Claim 8, wherein Said side members include anchoring points for lines extending from a parachute attached by a rod to a frame positioned in front of a frame to which the lines of that parachute are anchored in relation to the rotational direction of said shaft.

10. A device as claimed in Claim 9, wherein the canopy of each parachute comprises an equilateral triangular panel with one side sewn to the bases of two right angled triangular panels, the opposite sides of each triangular panel being sewn together to form an elongate pocket through which passes said rod, said aperture being located at the intersection of the sewn seams.

11. A wind propelled device, substantially as described herein with reference to Figures 3 to 8 of the accompanying drawings.