GB2481622A

GB2481622A - Wind direction indicator

Info

Publication number: GB2481622A
Application number: GB1011048.4A
Authority: GB
Inventors: Sergio Messina
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-07-01
Filing date: 2010-07-01
Publication date: 2012-01-04
Also published as: GB201011048D0

Abstract

The present invention relates to a wind direction indicator that is designed to withstand impact. The A wind direction indicator 10 comprises a direction indicator arm 32 and a flight arm 48 connected for rotational motion about an axial shaft 12, wherein the indicator arm extends radially from the shaft in one direction and the flight arm extends radially from the shaft in the opposite direction and each arm includes a resilient impact absorbing means 34, 46 arranged to absorb an impact to the arm that would otherwise bend the arm.

Description

WIND DIRECTION INDICATOR

The present invention relates to a device for indicating the direction of a fluid flow, in particular the device is for indicating wind direction on a sailing vessel.

A weathervane is a well-known device that is used for indicating the direction of wind. The weathervane comprises an arm pivotally mounted on a support with a pointer at one end and a flight at the other end. The pointer is normally a simple arrow shape, but the flight is often formed in ornamental shapes. The flight has a greater surface area so that the forces exerted on the weathervane move the arm so that the pointer indicates wind direction.

The present invention particularly relates to a wind direction indicator that is used for guidance when sailing boats, in particular for races. It is known to provide wind indicator devices for such circumstances and these known devices typically comprise a small weathervane-type rod made of a plastics material mounted on a fulcrum formed by the point of an upright shaft that is fixed to the boat. In small vessels, this will often be mounted on the bow of the boat, but may also be mounted at the front or the top of the mast. It is further known to provide such devices with fixed angle markers that are used to provide an easy reference marker for the vessels desired course relative to the vessels centre line as shown in US Patent No. 5,811,673. A number of designs of such wind direction indicators are known in the art, such as those shown in US Patent Nos. 4,080,826, 3,791,211, 5,127,358 and 7,267,073. GB Patent No. 2,439,787 discloses a weather vane with a particular design of the flight.

The wind direction indicators of the prior art are prone to substantial damage, especially when used in racing circumstances where the boom of a competing vessel will often impact the wind direction indicator and course substantially damage which often renders the device inoperable and irreparable.

The device must be able to function in a large range of wind strengths from light breezes to gale force strength gusts.

The present invention seeks to provide a wind direction indicator device for that is less prone to damage from impact.

According to a first aspect of the present invention, there is provided a wind direction indicator comprising a direction indicator arm and a flight arm connected together for rotational motion about an axial shaft, wherein the indicator arm extends radially from the shaft in one direction and the flight arm extends radially from the shaft in the opposite radial direction and each arm includes resilient impact absorbing means arranged to absorb an impact to the arm that would otherwise bend the arm at least 45 degrees and biased to return to the pre-impact position.

Although, the prior art devices were often made form materials such as plastics that were somewhat flexible, the devices could not absorb a substantial blow and the rod would often snap in such circumstance. In contrast, the device of the present invention includes a resilient impact absorbing means between the shaft and the flight and a resilient impact absorbing means between the shaft and the direction indicator. Thus an impact is absorbed in a non-destructive manner if the device is struck either in the vicinity of the direction indicator or the flight.

The wind direction indicator of the present invention will normally also comprise a pair of fixed angle marker arms adjustably mounted radially to the shaft when the direction indicator is used on a vehicle or sailing vessel. Each fixed angle marker arm resilient impact absorbing means arranged to absorb an impact to the arm that would otherwise bend the arm at least 45 degrees and biased to return to the pre-impact position. The fixed angle marker arms provide the user with a direction indicator of the desired direction of wind relative to the centreline of the vehicle or vessel.

It is preferred for the shaft to include impact absorbing means arranged to absorb an impact to the shaft that would otherwise bend the shaft at least 45 degrees and biased to return to the pre-impact position. Although, the flight and direction indicator element are the most prone to receive an impact, the shaft can also be readily damaged from an impact if no impact absorbing means is provided.

It is advantageous for the impact absorbing means to be able to absorb more force and so it is preferred for the, some or each impact absorbing means to be able to absorb an impact that would otherwise bend the arm at least 60 degrees, or more preferably at least 90 degrees.

It is currently preferred for the, some or each impact absorbing means comprises a helical spring as this provides a very large degree of impact absorption and can readily absorb repeated impacts, and can be implemented in a very cost efficient manner.

The currently preferred embodiment has the direction indicator arm and the flight arm axially spaced along the shaft. This allows the uses of a axis for rotation rather than balancing on a pivot.

In order to allow easy balancing of the wind direction indicator, it is preferred to have an indicator element mounted of the indicator arm that is adjustable to alter the lever force on the rotational connection.

According to a second aspect of the present invention, there is provided a flight, wherein the flight has a main surface that extends generally planar in the plane of the flight arm and shaft and a first plurality of fins that extend laterally to the main surface on one side of the main surface and a second plurality of fins that extend laterally to the main surface on the other side of the main surface.

The flight of the second aspect of the invention is advantageously fitted to the flight arm in a wind direction indicator of the first aspect of the invention.

The wind direction indicator will normally be provided as a kit.

The present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a side view of a preferred embodiment of the present invention; Figure 2 is a perspective view of the preferred embodiment of the present invention shown in Figure 1; Figure 3 is a top view of the preferred embodiment the present invention shown in Figure 1; Figure 4a is a perspective view of a preferred embodiment of the flight arm and direction indicator arm for use in the present invention; Figure 4b is a perspective view of a preferred embodiment of the flight arm and direction indicator arm for use in the present invention; Figure 5 is a perspective view of a preferred embodiment of a main shaft for use in the present invention; Figure 6 is a side view of a preferred embodiment of a fixed angle marker arm for use in the present invention; Figure 7 is a perspective view of a preferred embodiment of a flight for use in the present invention; Figure 8 is a perspective view of a bearing block for use in the present invention; Figure 9 is a perspective view of a fixed arm support for use in the present invention; Figure 10 is a perspective view of a mount for use in the present invention; and Figure 11 is a perspective view of a direction indicator for use in the present invention.

Please note that the Figures are not to scale, although the relative dimensions on each Figure are accurate. Thus the relative sizes of all the components may be calculated from Figures 1 to 3.

Figure 1 is a side view of a preferred embodiment of the wind direction indicator 10 of the invention. A perspective view is shown in Figure 2 and a top view in Figure 3. In use the wind direction indicator is mounted on a boat (not shown) so a shaft 1 2 is substantially upright when the boat is level. All directions, such as up and down refer to this orientation of the device.

Figures 1 to 3 show the device 10 where the shaft 1 2 is made from 2mm stainless steel wire and projects from centreline of a helical spring forming the shaft impact absorbing means 14. The shaft 12 is shown in more detail in Figure 5 where it can be seen that the impact absorbing means 1 4 is integrally formed with the shaft 1 2.

In use, the shaft impact absorbing means 14 is mounted in mount 1 6 that may be fitted to the bow or mast of a boat (not shown). The illustrated mount 16 is made from a plastic material into which the shaft impact absorbing means 14 is push fitted and is seen in more detail in Figure 10. The shaft 12 defines an axis. Of course, the shaft 1 2 does not have to have the associated impact absorbing means 14, but it is preferred for it to do so.

A fixed arm support 1 8 is fitted to the shaft about midway along the shaft 1 2 via an axial small channel which extend through the fixed arm support 1 8 in the axial direction. The small channel tightly fits to the shaft 12 and considerable force is required to slide the fixed arm support along the shaft 1 2. The fixed arm support 1 8 has two larger channels extending in the axial direction which larger channels may be open or closed. The fixed arm support 1 8 is shown in more detail in Figure 9 and is made from a plastics material.

A fixed arm 20 is fitted in to each of the larger channels of the fixed arm support 18. Each fixed arm 20 is formed from 0.91mm stainless steel wire and projects from centreline of a helical spring forming the fixed arm impact absorbing means 22.

The fixed arm 20 is shown in more detail in Figure 6, where it can be seen that the fixed arm impact absorbing means 22 is integrally formed with the fixed arm 20. As shown in more detail in Figure 6, in the axial direction from the fixed arm absorbing means 22, a further helical spring forming a fixed arm mount 24 is integrally formed at right angles to the fixed arm absorbing means 22. In use, the fixed arm mount 24 is mounted in one of the two larger channels in the fixed arm support 1 8 and this fit is sufficiently tight to allow the radial orientation of the fixed arm to be reliably set and maintained. At the distil end of the fixed arm 20 radially spaced from the shaft 14 an indicator 26 (best seen in Figure 3) is attached which is easily visual to the user. Of course, the fixed angle arms 20 do not have to have the associated impact absorbing means 22, but it is preferred for them to do so.

In sailing boats, particularly when racing, it is desirable to steer a course maximises the distance towards the destination over a particular time. The course to the destination will depend on wind strength and wind speed and will involve sailing either upwind or downwind with respect to the centreline of the boat. On average the boat centreline should be oriented at a particular angle with respect to the wind direction. This angle is generally dependent upon the upwind performance of the particular boat and the true wind speed and direction. Devices are known for indicating apparent wind direction which are intended to aid in maintaining a desired course and there use is well understood by sailors. Thus, the angle between the boat centreline (not shown) and the fixed angle arms 20 is set so that the user can follow a course based on this information.

A spacer 30 rests on the top surface of the fixed arm support 1 8 further axially from the mount 1 6 than the fixed arm support 1 8. The spacer 30 has a channel through which the shaft 1 2 extends and a bearing surface 30a on which rests one end of connecting rod 38. The spacer could be formed integrally with the fixed arm support 1 8 (embodiment not shown) for example as a projection therefrom. In any case, it is likely that the bearing surface 30a will be a different material from the rest of the fixed arm support such as PTFE or other material on which materials easily slide.

The connecting rod 38 extends in the axial direction generally parallel to the shaft 12 and is formed from 0.91mm stainless steel wire. Loops 40, 42 (best seen in Figure 4) extend about the shaft 1 2 at either end of the connecting rod 38 and allow the connecting rod to rotate freely about the shaft. Loop 40 rests on the bearing surface 30a and is integrally formed with a helical spring forming direction indicator impact absorbing means 34 extending radially from the shaft 1 2 to direction indicator arm 32. At the distil end of direction indicator arm 32 is a further coil is formed which acts as a support 37 for indicator element 36 (best seen in Figure 11).

Indicator element 36 has a channel into which the support 37 is movable radially inwardly and outwardly on direction indicator arm 32 to adjust the balance as described in more detail below.

Cap 44 is pushed on to shaft 1 2 at its end distil from the mount 1 6. Cap 44 acts as a stop for loop 42 of the connecting rod to prevent the connecting rod 38 disengaging the shaft, but is not generally in engagement with the loop 42 as that would prevent free rotation of the connecting rod 38 about the shaft 1 2.

A helical spring is formed integrally with loop 42 and forms flight impact absorbing means 46 which extends radially from the shaft to flight arm 48, the distil end of which is formed into a connector 50 to which flight 52 is fixed. The flight 52 has a generally planar surface in the plane defined by the flight arm 48 and shaft 1 2. The flight 52 has along the edge furthest from the shaft 1 2 a plurality of first fins 54 extending in one lateral direction and a plurality of second fins 56 extending in the opposite lateral direction.

It will be clear that the direction indicator 10 of the present invention is able to withstand substantial impacts without performance impairing damage. If any of the arms 20, 32, 48 or shaft 1 2 is struck the associated impact absorbing member 22, 34, 46 or 14 respectively allows the arm/shaft to deflect at least 45 degrees from its normal line. In fact, the illustrated embodiment allows for at least 90 degrees of deflection. The coils of the helical spring open on one side under the force of the impact and then return to the normal position after the impact ends. Other types of spring could be used or a resilient material such as rubber with a number of cuts are known to function in a similar manner to a helical spring. The helical springs are preferred in the current embodiment as they spring can be integrally form with the associated arm from the same material.

The flight arm 48 is coupled to the direction indicator arm 32 by connector rod 38 so as to extend radially in the opposition direction from one another. Both the flight arm 48 and the direction indicator arm 32 must be freely rotatable about the shaft with minimum resistance to rotation in order to accurately relay wind direction in low wind speed conditions. As mentioned above, the indicator element 36 is adjustable in the radially direction. The mass of the indicator element 36 and flight 52 are chosen so that the turning force on the connector rod 38 can be substantially eliminated by radial adjustment of the indicator element 36.

It will be appreciated that the flight arm 48 and the wind direction indicator arm 32 must generally extend in the same radial line to function and that the two arms 32, 48 must therefore be coupled for simultaneous rotation about the shaft. It is unique for the direction indicator arm 32 to be axially spaced from the flight arm 48.

Normally, these two arms are formed as a single arm rotating about a pivot.

Although the invention could adopt this configuration, the use of a connector rod in the axial direction is preferred. It will be noted that the illustrated embodiment uses an axis for the arms to rotate about rather than a pivot. This is preferred as it allows simple manufacture from resilient materials in a cost efficient manner. The assembly of the wind direction indicator 10 from a kit of components is a simple task.

The wind direction indicator 10 is used to indicate the direction of wind when placed in airflow with the direction of the airflow being the radial line extending along the flight arm 48 and wind indicator arm 32. When placed in an airflow, and the flight 52 is not aligned with the airflow, the moving air collides with the flight 52 and exerts a force on the vane that causes it to rotate about the shaft 1 2. When the flight 52 aligns with the airflow no further force is exerted by the airflow on the flight 52 but may continue to rotate due to the momentum of the rotating parts until airflow exerts pressure on the flight 52 from the opposite direction. When the flight 52 is aligned in the airflow, the air moves parallel to the generally planar surface of the flight 52. If the direction of the airflow changes, e.g. if the prevailing wind changes direction, then moving air once again collides with the flight. This causes the flight 52 to rotate about shaft 1 2 until the generally planar surface of the flight 52 is once again aligned with the airflow.

The flight must have a generally planar surface with a greater surface area than the area of the indicator element in the same plane. The skilled person is aware how to implement the flight based on their general knowledge. It should be noted that there are many different shapes of flight that may be used with the invention. Many designs have been proposed to reduce flutter and improve accuracy. Many of the principles used in aircraft are applicable.

The flight 52 of the illustrated embodiment is particular preferred. As can be seen from Figure 7, the flight 52 has a generally planar surface and has along the edge furthest from the shaft 1 2 a plurality of first fins 54 extending in one lateral direction and a plurality of second fins 56 extending in the opposite lateral direction. The two sets of fins are matched in that the total surface area of the first fins 54 is the same as the total surface area of the second set of fins 56. The fins 54, 56 are curved outwardly from the generally planar surface and project into the fluid flow, even when generally planar surface of the flight 52 is aligned with the airflow.

The flight 52 of the present invention is made from a light plastics material, such as polypropylene or polyethylene. It has a large generally planar surface area. This generates a relatively high torque about the shaft when turned by the airflow. The low weight means that turning force is generated even in very low wind speed conditions. The plurality of fins 54, 56 curve outwardly from the generally planar surface and greatly reduce flutter of the flight 52 compared to a planar flight.

Direction indicators incorporating a conventional flat flight can tend to be susceptible to flutter as the flight oscillates around the direction of fluid flow rather than remaining steadily aligned with the direction of fluid flow. Even though there is a reduction in speed as the direction indicator moves into alignment with the direction of fluid flow, the direction indicator can overshoot the point of alignment due to its angular momentum. Overshooting the point of alignment can cause a direction indicator to oscillate, as the flight is forced back and forth by the fluid impacting it first in one direction and then in the other until the angular momentum of the flight is reduced sufficiently for it to remain steadily aligned with the direction of fluid flow. Direction indicators that use substantially flat flights are especially prone to such oscillations. The fins 54, 56 act to reduce such oscillation.

The flight 52 of the invention can be used in any type of fluid direction indicator device and its use is not limited to the direction indicator 10.

The flight 52 has been designed as a low mass item that can be easily produced.

The indicator element 36 is elongate ovoid shape that is symmetric about its centre axis along the line of the wind direction indicator arm 32. It is shaped to offer low resistance to airflow from any direction so as to minimise counter-rotational torque generated in resistance to the torque generated by the flight 52.

In the illustrated preferred embodiment the arms and shaft are made of stainless steel wire, although other types of metal could be used and plastics and other materials could also be used. This is preferred because of the intrinsic resilience and durability of the material. The use of a metal wire allows the impact absorbing means to be integrated with the arms and shaft in the form of a helical spring which allows a very efficient manufacturing process. Of course, each or any of the impact absorbing means do not need to be integrated and could be a separate component if desired. Each or any of the impact absorbing means may be a helical spring, another type of spring or even a rubber member which could have slits for a greater degree of flexibility. Generally, the present invention relates to a wind direction indicator that is designed to withstand impact.

The applicant hereby discloses in separately each individual feature described herein and any combination of two or more such features. The applicant indicates that aspects of the present invention may consist of any such feature or combination of features. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims

-1 1-.CLA I MS: 1. A wind direction indicator comprising a direction indicator arm and a flight arm connected together for rotational motion about an axial shaft, wherein the indicator arm extends radially from the shaft in one direction and the flight arm extends radially from the shaft in the opposite radial direction and each arm includes resilient impact absorbing means arranged to absorb an impact to the arm that would otherwise bend the arm at least 45 degrees and biased to return to the pre-impact position.
2. The wind direction indicator according to claim 1, further comprising a pair of fixed angle marker arms adjustably mounted radially to the shaft, each fixed angle marker arm resilient impact absorbing means arranged to absorb an impact to the arm that would otherwise bend the arm at least 45 degrees and biased to return to the pre-impact position.
3. The wind direction indicator according to claim 1 or claim 2, wherein the shaft includes impact absorbing means arranged to absorb an impact to the shaft that would otherwise bend the shaft at least 45 degrees and biased to return to the pre-impact position.
4. The wind direction indicator according to any one of the preceding claims, wherein the, some or each impact absorbing means is arranged to absorb an impact that would otherwise bend the arm at least 60 degrees, or more preferably at least 90 degrees.
5. The wind direction indicator according to any one of the preceding claims, wherein the, some or each impact absorbing means comprises a helical spring.
6. The wind direction indicator according to any one of the preceding claims, wherein the direction indicator arm and the flight arm are axially spaced along the shaft.
7. The wind direction indicator according to any one of the preceding claims, further including an indicator element mounted of the indicator arm so as to be adjustable to alter the lever force on the pivotable connection.
8. The wind direction indicator according to any one of the preceding claims, further including a flight fixable to the flight arm, wherein the flight has a main surface that extends generally planar in the plane of the flight arm and + shaft and a first plurality of fins that extend laterally to the main surface on one side of the main surface and a second plurality of fins that extend laterally to the main surface on the other side of the main surface.
9. A kit comprising the wind direction indicator of any one of claims 1 to 8.
10. A wind direction indicator as hereinbefore described with reference to and/or as illustrated by the accompanying drawings.
11. A flight for a wind direction indicator as hereinbefore described with reference to and/or as illustrated by the accompanying drawings.*::r: INTELLECTUAL . ... PROPERTY OFFICE Application No: GB 1011048.4 Examiner: Mr Mike Walker Claims searched: ito 10 Date of search: 19 September 2011 Patents Act 1977: Search Report under Section 17 Documents considered to be relevant: Category Relevant Identity of document and passage or figure of particular relevance to claims X 1,2,5,9,11 U56733357 Bi (WEISER) see abstract; col.2,11. 12-29 X 1,2,9,11 US4080826 A (PERRETTA) see abstract; fig.2;col.3,ll.3-25 X 11 GB2439787A (JUDE BARKER-MILL) see abstract; fig.3 X ii US337i529A (TILLMAN) figure 5; col.4, line 36 etc A i US5085075 A (BAKER) col.i,ll.5 to ii A 1 US4597287 A (THOMAS) see abstract Categories: X Document indicating lack of novelty or inventive A Document indicating technological background and/or state step of the art.Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of before the filing date of this invention.same category.& Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:Search of GB, EP, WO & US patent documents classified in the following areas of the UKCX: Worldwide search of patent documents classified in the following areas of the IPC GO1P The following online and other databases have been used in the preparation of this search report EPODOC, WPI Intellectual Property Office is an operating name of the Patent Office www.ipo.gov.uk *.:r: INTELLECTUAL . ... PROPERTY OFFICE International Classification: Subclass Subgroup Valid From None Intellectual Property Office is an operating name of the Patent Office www.ipo.gov.uk