EP0075544A2

EP0075544A2 - Oar for windsurf

Info

Publication number: EP0075544A2
Application number: EP82830238A
Authority: EP
Inventors: Romano Gnagnetti
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-09-21
Filing date: 1982-09-21
Publication date: 1983-03-30
Also published as: GR78043B; EP0075544A3

Abstract

An oar is described suitable to be used in wind-surfing which, on one end, or blade, has a pair of blades (3,3a) pivoted on the said end (2), rotating essentially about the longitudinal axis of the oar. Means (7) are provided which limit the moving away stroke of the blades (3, 3a) and means (9) which prevent the blades from coming into contact with one another.

Description

The present invention concerns an oar suitable for use in the known sport of wind-surf in which the user takes a substantially elongated surf-board fitted with a keel and a manoeuvrable sail.
The oar according to the present invention is used to advantage in the event that the surf-board, when far from the shore, cannot be made to return to shore due to a sudden drop in wind speed which makes the sail unuseable.
This inconvenience is well known to keen wind-surfers who, at present, do not have suitable equipment to face and overcome the probable situation mentioned above. In fact, it is known that those who engage in the sport in question wish to enjoy the widest possible freedom of movement to manoeuvre the sail which is the only means to control their craft.
Now an oar has been invented and constitutes the subject of the present invention that is suitable for use particularly in wind-surfing, which makes it possible to solve the above mentioned problem, easily and efficiently, permitting the user to return to shore in every case.
The oar according to the invention is characterised by the fact that its end part, or blade is realised by a pair of blades pivoted on the said ends rotating substantially about the longitudinal axis of the oar a first stop means being foreseen capable of limiting their rotations in the direction of their moving away stroke as well as a second stop means in the direction of their approaching stroke, capable of preventing the said blades from coming into contact with one another.
The characteristics of the oar according to the present invention will appear obvious from the following detailed description of a number of its non-limiting embodiments made with reference to the figures attached, of which:

FIGURE 1 is an exploded partial view with partly removed areas of a first embodiment of the oar according to the invention;
FIGURE 2 is a view of the oar shown in figure 1 fully mounted;
FIGURE 3 is a view of the oar of figure 2 as per section III - III of the same figure;
FIGURE 4 is a view showing an embodiment of the oar according to the invention;
FIGURE 5 is a view showing a further embodiment of the oar according to the invention;
FIGURE 6 is a view showing another embodiment of the oar according to the invention;
FIGURE 7 is a view of the oar of figure 6 as per section VII-VII of the same figure;
FIGURE 8 is a view showing another embodiment of the oar according to the invention;
FIGURE 9 is a view of the oar of figure 8 as per section IX-IX of the same figure.

Now by making special reference to the figures 1 to 3 the first embodiment of the oar is described according to the invention.
The oar according to the invention essentially consists of a handgrip I which, at one end extends in an assentially rodshaped appendix 2 to which a pair pf blades 3, 3a is applied that will constitute the actual rowing organ.
The blades 3, 3a are realized in a plate shape on one edge of which ring elements 4, 4a are provided capable of being inserted on the oar appendix 2. As appears in particular from figure 1 the ring elements 4 of the blade 3 and the ring elements 4a of the blade 3a are off-set respect to one another so that each one of the ring elements may introduce itself in the opening between the adjacent opposite ring elements forming substantially a comb structure on the appendix 2, as shown particularly on figure 2.
The blades 3, 3a applied in this way to the appendix 2 of the oar may rotate about its longitudinal axis. According to one of the fundamental characteristics of the oar according to the invention such rotations are limited by the first and second stop means respectively to permit the blades 3, 3a to take a substantially flat configuration to realise the active phase of the stroke and to avoid them from coming into contact with one another by adhering to one another thus obstructing, if not preventing the successive stroke. Such means are described below.
The first stop means mentioned above are made up of an essentially ring wall sector 7 made in a single piece on the hand-grip 1 which is extended at an angle to the centre, the value of which will determine the relative angle of rotation between the blades 3, 3a. The wall sector 7 is essentially coaxial to the longitudinal axis of the appendix 2 and extends longitudinally for a part of the length of the latter. As appears in particular in figure 3 when the blades 3, 3a will be positioned as represented with the dashed and dottled line their rotation will be stopped by the lower edges of the wall sector 7. Therefore they can assume a substantially flat configuration for the active phase of the stroke.
Further stop means of the rotations of the blades 3,3a are associated with the wall sector 7 and such means are directly on the ring elements of one of the two blades, in particular on the ring elements 4a of the blade 3a. As appears more clearly in particular from figure 3 such means consist of radial projections essentially tooth shaped 8 capable of engaging with the blade 3 in the position of maximum extension of the blades represented with a dashed and dottled line in figure 3.
The oar according to the invention is also fitted with means capable of preventing the blades 3, 3a from coming into contact with one another in the dead phase of the stroke, hence avoiding them from adhering with one another obstructing, if not preventing the successive stroke. Such means consist of a pin 9 on the hand-grip 1 which extends longitudinally and parallel to the appendix 2 of the oar for a part of the length of the latter. The pin 9 is arranged with respect to the wall sector 7, on the side opposite to the appendix 2 so that the blades 3, 3a stop against it when they approach one another as shown with the continuous line in figure 3. Operation of the oar, as described above is therefore clear.
Figure 4 represents a first embodiment of the oar, according to the invention, particularly efficient in respect of the intensity and the amplitude of the stroke achievable. Also in this case the oar consists of a hand-grip 1 which extends in a stock 2 having a length greater than the previous realisative form, which is made up of two segments 2a, 2b the complex of the two blades 3, 3a is foreseen at the end of the latter as previously described.
According to this embodiment the opposite ends of the two segments 2a, 2b have a substantially rounded profile, in particular with a cylindrical shape and the end of the segment 2a has a larger diameter than that of the end of the segment 2b. Teething 10, 11 which engage reciprocally are on the opposite side surface of the said ends.
The connection of the segment 2a to the segment 2b to keep the two parts together and to permit their reciprocal rotation is achieved using metal plates, or bars 12 ( only one of which is visible in figure 4 ) fixed to the ends in any known way to pins 13 on which the segments 2a, 2b of the oar are pivoted.
The advantages deriving from the use of the oar according to this realisative form are obvious.
It may be easily applied directly on the board by making, for example in the keel housing, two special grooves, or recesses of equal size as those of the connecting bars 12 so that the articulated joint made by the gears 10, 11 is fixed to the board.
Therefore, it will be sufficient for the user to grasp the hand- grip 1 to control the rotation of the toothed end 10 of the oar segment 2a and this will cause a contrary rotation, but through a greater angle, of the segment 2b of the oar stock 2. In this way the efficiency of the stroke, i.e. the action made by the open blades 3, 3a, will be intensified with respect to that made by the user. By way of an example if a 2 to 1 ratio is formed between the gears 10,11 the angular travel of the segment 2b will be doubled and it will be equal to that achievable with an oar stock of greater length than that of the embodiment in question.
Figure 5 represents a further executive form of the oar according to the invention.
According to this realisation the oar has a greater length compared to the previous realisative forms and may be used as a traditional oar. In fact, from figure 5 it is noted that the oar in the realisative form of figures 1 to 3 has a blind longitudinal hole 14 on the hand-grip sealed by a plug 15 applicable for example by pressing which, once removed, permits the application of an extension rod 16, with another hand-grip 17 on its end.
The extension rod 16 has a projection on pin 18 projecting radially in its intermediate area, which may be inserted in a suitable slot made on the wind-surf board.
For example by pre-disposing two slots on the two surfaces of the board, the former will function as a rowlock as in normal rowing boats.
In figures 6 and 7 another realisative form of the oar according to the invention is represented, which however is very similar to that of figures 1 to 5_° In figures 6 and 7 the same elements of the previous figures are indicated with the same reference numbers.
In this embodiment the tooth projections 8 of the realisative form as per figures 1 to 3 are not foreseen, but rather only a special shaping of the end of the rod-shaped appendix 2 which performs the same action as the wall sector 7. The rod-shaped appendix 2 in correspondence to the end to which the blades 3, 3a are applied, has two radial perpendicular appendixes 19 which permit the application of a support pin 20 on which the blades 3, 3a are inserted, in particular the pin 20 is inserted inside the holes of the appendixes 19 and is fixed on the latter via a nut 21.
The pin 9 already described for the previous embodiment is fixed in any known way to one of the appendixes or walls 19.
As may be noted, in particular, in figure 7 the stop means of the opening of the blades in accordance with the direction of the arrowes F of the same figure consist of two inclined radial parts 22 made in a single piece on the rod shaped appendix 2. The walls 22 have a flat part against which the blade will rest at the end of its rotation.
Another embodiment of the oar according to the invention substantially similar to that of figures 6 and 7 is represented in figures 8 and 9. The fundamental difference consists in the fact that the stop means at the opening of the blades are applied to the appendix 2 of the oar instead of being in a single piece with the latter, as in the previous realisative form.
In figures 8 and 9 the same elements of figures 6 and 7 are indicated with the same reference numbers.
The walls 22 in this case are in a body which, in transversal section, has a substantially trapezium shape the smaller base of which is applied using nails 23 to the end of the rod-shaped appendix 2. The nails 23 will be suitably riveted both for fixing and for safety reasons.
Furthermore the holes 24 on the walls 19 may be noted which permit the application of the pin 20 on which the blades 3, 3a will be pivoted.
The pins 9 are in this case made in a single piece together with the walls 19.
The last embodiment just described is particularly advantageous since in the event of failure of the means that support the blades 3, 3a they may be replaced by removing them from the remaining part of the oar without having to replace the oar completely, at least that part which supports the blades; as is the case for the previous embodiment.
It is clear that variants and/or changes may be made to the oar according to the present invention without by so doing departing from the scope of the invention itself. In particular, the shape and the way of pivoting the ring elements of the blades to the oar may be modified. In relation to this it must be noted that the said ring elements are open in the embodiment as detailed in Figs. 1 to 3 while they are closed for the embodiment in Fig.7. However, this detail does not come within the scope of the present invention.

Claims

1. Oar particularly suitable to be used for wind-surf, characterised by the fact that its end part, or blade is realised by a pair of blades 3, 3a pivoted on the said end rotating substantially about the longitudinal axis of the oar, there being first stop means 7,8 provided capable of limiting their rotations in the direction of the moving away stroke as well as second stop means 9 in the direction of the approach stroke capable of preventing the blades 3, 3a from coming into contact with one another.

2. Wind-surf oar according to claim 1, characterised by the fact that the blades 3, 3a on one of their edges, have ring elements 4, 4a respectively, the ring elements 4 of one blade being offset with respect to the elements 4a of the other blade, so that, once applied to the oar stock, they form a substantially comb structure.

3. Wind-surf oar according to claims 1 and 2 characterised by the fact that the blades 3, 3a are hinged on an appendix substantially rod-shaped 2 of one hand-grip 1 of the oar.

4. Wind-surf oar according to claims 1 to 3 characterised by the fact that the first stop means able to limit the rotations of the blades in the direction of their opening consist of a wall sector 7, made in a single piece with the hand-grip 1, this wall sector being essentially coaxial to the rod-shaped appendix 2.

5. Wind-surf oar according to claims 1 to 3, characterised by the fact that the first stop means able to limit the moving away stroke of the blades 3, 3a consist of tooth projections 8 made on the ring elements 4a of one of the two blades.

6. Wind-surf oar according to the previous claims, character - ised by the fact that the second stop means in the approach stroke direction of the blades 3, 3a consist of a pin 9 extending longitudinally and parallel to the rod-shaped appendix 2 and integral with the hand-grip 1.

7. Wind-surf oar according to the previous claims, characterised by the fact that the hand-grip 1 has a blind longitudinal hole 14 sealed at one end by a removeable plug 15.

8. Wind-surf bar according to the previous claims, characterised by the fact that an articulated joint 10,11 is applied on an intermediate area of the oar stock 2.

9. Wind-surf oar, according to claim 7, characterised by the fact that the said articulated joint consists of toothed ends 10,11 of the two parts 2a, 2b making up the oar stock 2, the said parts have a circular shape and a different diameter, the parts 2a, 2b of the oar stock 2 being connected with one another by connection plates 12.

10. Wind-surf oar, according to the previous claims, characterised by the fact that an extension stock 16 is applied inside the blind hole 14 of the hand-grip 1, the said extension stock having a radial projection 18 able to be inserted inside a suitable slot of the wind-surf board.

11. Wind-surf oar according to the previous claims, characterised by the fact that the blades 3, 3a are hinged to a pin 20 fixed to radial projections 19 of the oar stock 2, the said projections being connected by walls 22 capable of acting as a stop for the moving away stroke of the blades.

12. Wind-surf oar according to the previous claims, characterised by the fact that the sides 19 which support the pin 20 to pivot the blades 3, 3a and the walls 22 are realised in a single body fixed to the oar stock 2 so as to be detachable.

13. Wind-surf or substantially as described above and represented in the attached figures.