Field of the Invention
[0001] The object of the present invention pertains to improvements in the oars of watercraft,
such as small boats, boats and the like, which have considerable advantages, in particular
for the oarsman in the direction of moving, compared with prior-art oars.
Prior art of the Invention
[0002] The traditional rowing system has always been performed in such a manner that there
are three basic points:
1) The blade that is in contact with the water and forms the support.
2) The opposite end of the oar, which is handled by the oarsman, which forms the point
of application of power.
3) A point between both ends, at which the oar is joined to the boat and forms the
place where the resistance of the vessel is overcome.
[0003] Due to the physical nature of the human body, it is capable of building up a greater
force when the forearm is bent on the arm that when it is extended. For this reason,
rowing is always done such that the oarsman drives the boat by supporting the blade
on the water in the bending movement of the forearm and by removing it (blade) from
the water to move the blade backwards through the air, which coincides with the extension
of the forearm in a movement of less energy buildup.
[0004] When the forearms are bent in order to support the blade in the water, the boat,
whose contact with the oar is located between both ends of same, is driven such that
is advances behind the oarsman, and for this reason, rowing has always been done backwards
to the direction of navigation when the oar rests in the boat.
[0005] Navigating backwards leads to various drawbacks, the most evident of which is that
the navigator does not see what he is approaching, which forces him to make frequent
twisting manoeuvres of his back and neck and may also be the cause of deviations in
the route or of a collision with fixed or moving obstacles that were not seen.
[0006] Attempts have been made to introduce various improvements in the assembly and the
shape of the oars, e.g.: Spanish Patent Application No. 9201415 refers to a mechanism
for increasing the lever arm and, consequently, the force exerted by the blade of
the oar on the basis of a complex series of braces and accessory crossbars; European
Patent no. 0364954 dealt with a rowing machine, with which attempts were made to increase
the speed; and Spanish Patent No. 491458 dealt with a propulsion means for watercraft
based on a crankshaft, which, driven by means of pedals, brings about an alternating
movement of some propulsion blades. Nevertheless, none of them anticipates the improvements
with the corresponding advantages that are proposed below.
Brief Description of the Invention
[0007] To overcome the drawbacks described, improvements in the oars are proposed such that
the propulsion of the boat is carried out in the anterograde direction with regard
to the oarsman, i.e., rowing is done forwards, while simultaneously maintaining the
system, in which the propulsion is created by means of bending the forearm, which
is most suitable because of the human anatomy and physiology.
[0008] Therefore, the present invention consists of an articulated oar, which is interrupted
at a point located between the blade and the opposite end, and both parts are each
joined by toothed ends. This produces the reverse of the moving with respect to the
rowing direction as will be explained.
Detailed Description of the Invention
[0009] In order to facilitate the explanation, two sheets of drawings, in which a practical
embodiment is shown, which is mentioned only by way of example, which does not limit
the scope of the present invention, are attached to the present specification.
[0010] In the said drawings:
Figure 1 shows a top view of the middle part of the oar where it has its articulation;
Figure 2 shows a schematic top view of a boat, in which the directions of rowing and
advancement of the boat itself are seen;
Figure 3 shows a cross section with regard to the front of Figure 1;
Figure 4 is another top view corresponding to another articulation of the middle part
of the oar; and
Figure 5 corresponds to a longitudinal, elevated view with regard to the front of
Figure 4.
[0011] According to these figures (Figures 1 and 2), the improvements, which are the object
of the present invention, basically consist of articulating the oar in two parts:
one part (1), which is driven by the oarsman (3), and another part (2), which guides
the blade (4). The fact that the facing ends of the said two parts (1, 2) are each
provided with teeth (5, 6), which are meshed with another and which pivot on corresponding
axles (7, 8), is fundamental.
[0012] Thus, when the oarsman (3) bends his right arm and pulls towards himself (Figure
2), the end of the oar grasped by the hand (M) rotates the teeth (5), viewed from
above, in a counterclockwise direction.
[0013] When (5) rotates in a counterclockwise direction, the toothed articulation makes
(6) rotate in a clockwise direction.
[0014] When the toothed end (6) rotates in a clockwise direction, the end of the blade (4)
is driven backwards inside the water, whereby the boat (10) is driven forwards, towards
the front of the oarsman, which leads to the boat (10) moving forwards, with the same
physical work having been carried out as in the case of a traditional oar.
[0015] Note that the rotations described for the teeth on the starboard side will have the
opposite sign for their counterparts on the port side.
[0016] In a second manoeuvring phase, the oarsman (3) must again bring the blade (4) forwards,
through the air, in order to be able to repeat the same propulsion manoeuvres.
[0017] In the traditional system, in order for the oar to go through the air, the oarsman
brings his hands downwards so that the end of the blade is raised over the water,
does not offer resistance and does not counteract the moving forward.
[0018] With the oars, which are the object of the improvements according to the present
invention, it is provided (Figure 3) that, so that the oarsman (3) is able to remove
the blade from the water and to move it forward through the air, the two articulated
parts (1, 2) of each oar have a common base, which is convex, has a hemispherical
surface (9) or the like, in which the axles (7, 8) are lined up, and that the said
base can be inserted in a recess (11) of the same shape provided in the bulwark, such
that, when the oarsman pushes the end of the oar (M) downwards, he makes the common
base (9) tilt, so that the part (1) drops and the part (2) rises, and he manages to
get the blade (4) to leave the water.
[0019] In this position, and with the hands lowered, the extension of the right forearm
moves (M) forwards (dash-dotted lines in Figure 2), makes (5) rotate in a clockwise
direction, which leads to a counterclockwise rotation of (6) and to a displacement
of the blade (4) forwards or the end of the part (2) through the air, and he (the
oarsman) will again be in a position to stop the blade (4) from falling into the water
and to start a new manoeuvre for advancing the boat.
[0020] Hooks, like the axles (13), which are inserted in respective grooves (14) of the
convex base (11) itself, one of which, at least, can easily be removed in order to
be able to detach the articulated oar (1, 2) from the boat when it has reached the
shore, have been provided so that the convex base (11) mentioned is maintained in
the bulwark (12) and does not escape.
[0021] While the teeth (5, 6) provided at the ends of each part of the oar (1, 2) themselves
were shown in the embodiment of Figure 1, the said ends shown in the embodiment of
Figures 4 and 5 are lined up with respective pinions or toothed wheels (5a, 6a), which
are enclosed in a housing (15) having lateral openings (20), pivoting back and forth
in the neck (16) of the bulwark (12) by means of two half-axles (17, 18), which are
fixed in the edge of same, in order to make it possible for the corresponding oar
to be able to be inserted into the water when driving the boat, or to be able to be
removed from it (water) in order to again return to the situation of stopping the
blade (4) from falling into the water, as was already explained above.
[0022] In addition to achieving the principal object of the present improvements, thanks
to the same toothed articulation design already described, an additional advantage
is achieved: the toothed ends (5, 6) or pinions (5a, 6a) do not have to necessarily
have the same diameter or number of teeth, but it is possible to have a distinct ratio
between them, as shown in Figure 4. In this manner, the power/rowing angle of the
parts (1, 2) of the oar can be varied respectively.
[0023] In other words, with a small pinion (5a) at the end of the part (1) of the oar driven
by the oarsman (3) and a large wheel (6a) at the end of the part (2) of same corresponding
to the blade (4), the force necessary for its running is reduced, but also the rowing
angle within the water and therefore the speed of advancement of the boat are reduced.
By making the former pinion large and by making the said wheel small, more force is
needed to row, but the rowing angle would also be large, and the whole thing follows
one of the basic principles of mechanics. As explained above, at least one of these
half-axles (17, 18) shall be able to be easily removed.
[0024] In its essence, the present invention can be achieved in practice in other embodiments,
which differ only in detail from the embodiment that was given only by way of example,
to which the protection that was applied for extends as well. Thus, these improvements
may be achieved in oars of boats with the most suitable means, components and accessories
by all being included within the spirit of the following claims.
1. Improvements in oars of boats, characterized by providing the oar in question with
a toothed articulation, which divides the oar into two parts: a part (1) grasped by
the oarsman (3) and a part (2) carrying the blade (4), said articulation being fastened
in a pivoting manner in the bulwark (12) of the said boat (10).
2. Improvements in accordance with claim 1, characterized in that the said articulation
consists of toothed portions (5, 6) of each facing end of the said two parts (1, 2)
of the oar.
3. Improvements in accordance with claim 1, characterized in that the said articulation
consists of toothed pinions or wheels (5a, 6a) each assigned to both facing ends of
the said two parts (1, 2) of the oar.
4. Improvements in accordance with the above claims, characterized in that the said articulation
is mounted on a base, such as a hemispherical housing (9), which is inserted in a
pivoting manner with regard to an axle perpendicular to the oar, and is detachable,
in a recess (11) having a similar shape that is provided in the said bulwark (12)
of the said boat itself (10).
5. Improvements in accordance with claims 1, 2 and 3, characterized in that the said
articulation is enclosed in a housing (15) with lateral openings (20), which is mounted
in a pivoting manner with regard to an axle that is perpendicular to the oar, and
detachable, in the bulwark of the boat itself.
6. Improvements in accordance with the above claims, characterized in that the ratio
between the said gear teeth (5, 6, 5a and 6a) of the said articulation is 1:1.
7. Improvements in accordance with the claims 1 through 5, characterized in that the
ratio between the said gear teeth (5 and 6, 5a and 6a) of the said articulation is
different from 1:1.