Rope tension adjustment system applicable to windsurfing mast feet.

Abstract

Mechanical tension adjustment system for ropes applicable to the feet of windsurfing masts. In the proposed system, the rope 6 circulates between a pulley 7 and a cam 10 which presses the rope against the pulley and blocks it. A handle 9 rotating around the axis of the pulley allows the rope to be blocked against the pulley by a crushing force against the pulley and thus to pull on the rope. The pulley has notches on its periphery which collaborate with a lug 11 secured to the cam 10. This creates a ratchet effect on the pulley but also allows the cam to be raised when the pulley is rotated. This gives positions where the rope is no longer trapped by the cam and where the tension release can be managed. Figure for the abstract: Fig. 4

Description

Title of the invention: Tension adjustment system for ropes applicable to the feet of windsurfing masts.

[0001] The present invention relates to a system for managing (tightening-relaxing) the tension of a rope. It can be applied to the field of nautical sports (downhauls, halyards) and in particular to adjusting the tension at the foot of the mast of sailboards. Other applications can be envisaged, without this list being limiting, we can cite: tensioning a zip line, working on rope or tightrope walking.

[0002] On modern sailboards, adjusting the mast tension is important both in terms of strength and performance. Too little adjustment will result in a sail that is too hollow, while a tighter adjustment will flatten the sail. It is therefore important to match this tension to the wind strength. As the wind can vary, it is important to be able to change this tension easily and on the water.

[0003] Most mast bases actually have a 6-strand tackle and tensioning is done by locking the rope on a bar held with one hand and then pushing the mast base back with one leg or sometimes both. Some brands advertise the comfort of the shape of the base for barefoot use. It is then necessary to press the rope into the jammer by changing the angle of the rope relative to the mast to reposition it in the jammer. The jammer is of the V-notch type. Continuously pulling the rope through the jammer is not desirable because it causes wear on the rope and the jammer, which eventually loses its effectiveness.

[0004] To loosen the rope, it is advisable to use a similar gesture. Pulling the rope simply by hand to release it from the jammer is completely illusory and damaging to the hand.

[0005] In addition, this mechanism must be located as low as possible on the mast, so that the sail can descend as close as possible to the windsurf board.

[0006] It is therefore advisable to integrate it into the hoist. If the mechanism is higher than the pulleys integrated into the mast foot, this will limit the hoist's travel; if it is lower, it risks rubbing on the board.

[0007] Finally, below the mast foot comes a joint that connects the mast foot and the sail to the float. This joint must not be hindered by the mechanism or vice versa: to use the mechanism on the water, it must not be necessary to separate the sail from the float, which would present an unacceptable risk of loss of the float and subsequently drowning.

[0008] The problem is therefore not limited to introducing a lever such as in patent US5511503A.

[0009] Various aids for tensioning already exist. Crank-operated furlers such as in WO0202397A1 are commercially available but can only be used when the sail is detached from the board. Patent DE19738117A1 lists many of these possibilities for attaching the bottom of the sail to a hook on the mast foot.

[0010] Systems exist where instead of pulling the sail on an extension of a pre-defined length, it is the length of the extension that is increased to tension the sail: Patent EP0257410A2, DE3633752A1 (1986). But those marketed also require muscular strength incompatible with use in the open sea.

[0011] The most popular system currently is a ratchet mast foot or a lever adds a reduction to that of the hoist

[0012] Patent FR2677946A1 presents a ratchet system for winding onto a drum. This can only work if the length of rope to be taken up remains short, which is not the case on modern sails.

[0013] The system currently marketed by the company Duotone (formerly NorthSails) is more similar to that of patent WO02070393A1 where a jamming pulley is driven and locked by a ratchet system.

[0014] This system, however, has flaws.

[0015] First of all, jam pulleys act as brakes and not as jammers. They require a rope pressure mechanism.

[0016] Between the upstream and downstream of the pulley, these pulleys reduce without canceling the traction on the rope and a residual traction on the free strand remains and it is appropriate to compensate for it by tightening in the groove of the pulley. If this pressure on the free strand is fixed, beyond a certain load, slippage occurs.

[0017] Thus, in patent EP0050073A1 of April 21, 1982, there is a pressure roller exerting a force to press the free strand into the groove with a force that is all the greater as the tension on the taut strand is greater.

[0018] This need to press the rope into the pulley groove leads to disadvantages. This complicates the mechanism. It also complicates the installation of the rope and can make the proper functioning of the mechanism very dependent on the rope used and its condition, especially if the pressure on the free strand is not adjustable.

[0019] In the only mechanism currently marketed on a large scale, the dependence on the type of rope is proven as well as on its degree of wear. Since the rope cannot easily be passed through the mechanism, the tackle has been reduced to 4 strands in order to be able to just pass a loop through the sheaves of the sail then around the second pulley at the foot of the mast.

[0020] More annoying, to relax the sail, the release is done notch by notch by a sudden movement which makes the active notch of the ratchet jump. And depending on the model of mast foot, this action is not possible without detaching the sail from the board, which limits the adjustment possibilities. This also causes wear of the mechanism and the release becomes problematic over time. Fortunately, it is a cleat which blocks the second end of the rope and it remains possible to relax the sail by traditional means but with the difficulty of a 4-strand tackle instead of 6.

[0021] Beyond the case of windsurfing, adjusting the tension of a rope can be done by various means.

[0022] On sailboats, this problem is encountered when adjusting the downhaul, a tackle that is used to pull the bollard downwards. A fairly practical system consists of having a ratchet on the last pulley before a jam cleat, often of the type with two converging articulated cams. This pulley, shaped to brake the rope, will allow the tension to be gently released once the rope is freed from the cleat. The shape of the cams on cam cleats allows for similar locking for a wide range of rope diameters.

[0023] To tension the halyards that hold the sails taut at the top of the mast, a winch and a manual jammer are generally used, which are then operated to lock the halyard once it is taut. This allows the winch to be freed for another use. To slacken, the winch is used again to tighten the halyard, which allows the pressure on the jammer to be released and freed. The rope can then be let slide around the winch drum to control the descent of the sail.

[0024] In light of these different examples; we understand that to manage the tension of a rope, it is necessary to be able to pull on it, block it and also let it slide in a controlled manner. The blocking can occur before (case of halyards) or after the means of traction.

[0025] For a windsurfing mast foot, in order to obtain a compact system, it is necessary to merge the tension and locking systems.

[0026]

[0027] Object of the invention

[0028] To overcome the above drawbacks presented on existing windsurfing mast feet, the device according to the invention is characterized in that the locking means is provided not by a V-groove jammer but by a cam jammer. Thus, the rope can be pulled through the jammer with limited friction and wear, the traction means is itself constituted by a pulley of adapted shape increasing the friction on the rope and driven by a lever having a means manual for pressing the rope against this pulley during the tensioning phases, and that the rope is jammed by a cam of adapted geometry (notches, teeth, pins) pressing the rope against the pulley.

[0029] According to a preferred embodiment, the jammer is reduced to a cam pressing the rope against the pulley and a non-return pawl is provided on the pulley. In addition, this non-return pawl can be provided by a lug on the cam which will jump from notch to notch on a notched crown on the periphery of the pulley. This configuration induces a reduction in the number of parts but also mechanical advantages.

[0030] The rotation of the pulley driven by the rope increases the cam's grip on the pulley. The blocking is therefore powerful. But also, conversely, the rotation of the pulley to increase the tension lifts the cam. So that to relax slightly, the tension can be taken up with the jamming pulley, which lifts the cam. And by keeping the cam raised manually, the pulley can be allowed to return a few notches. There is then no slippage of the rope in the pulley or on the cam, which preserves the longevity of the equipment.

[0031] At the angular positions of the pulley between the locking notches, the cam remains raised, so that, if the locking of the rope on the pulley can be manually controlled, it is possible to let the rope slide gently over a long length in a raised cam position. This action should be preferred to finish loosening the tackle when folding the sail, once the tension has been reduced by the first means indicated. Indeed, if the tension of the rope is high, the friction on the pulley in an environment where the presence of sand is likely could prematurely wear out the elements in contact.

[0032] By positioning the cam upstream of the jamming pulley, there will be great freedom of use of the slack strand and it will be possible, for example, to pass it through a friction system dedicated to controlled release of the tension.

[0033] Thus, to control the release, it is possible, with the proposed configuration, to pass the rope through one of the notches of the pulley and then let it rub on this notch.

[0034] For installation, you can also wedge the rope into one of the notches and by turning the pulley, pass the rope through the mechanism.

[0035] Conversely, once the rope is slack, by passing the rope through the notch just above the cam, this prevents the ratchet effect on the pulley and it can therefore turn in reverse, pulling the rope out of the jammer.

[0036]

[0037] Brief description of the drawings

[0038] The attached drawings illustrate the invention and will make it possible to visualize other advantages and characteristics:

[0039] Figure 1 shows the general context of a windsurfing mast foot.

[0040] Figure 2 shows a right side view of a preferred embodiment.

[0041] [Fig. 3] is a sectional view from the left and allows the interior of the mechanism of a preferred embodiment and the path of the rope to be visualized.

[0042] [Fig.4] is a sectional view from the right and allows the interior of the mechanism of a preferred embodiment to be visualized and in particular the interaction between the pulley and the cam.

[0043] Figures 5 and 6 show a controlled relaxation action.

[0044] [Fig.7] illustrates another means of controlled relaxation.

[0045] Figures 8 and 9 illustrate how to remove the rope from the mechanism or insert it into it.

[0046] .

[0047] With reference to these drawings:

[0048] [Fig. 1] shows a mast foot 1 which is used to tension the sail 2 downwards. The sail is threaded onto a mast 3. This mast comes into contact with a ring 4 which is used to adjust the length of the extension 5. A rope 6 forms a six-strand tackle to increase the pulling force. For reasons of clarity, the entire tackle is no longer shown.

[0049] [Fig.2] shows a preferred embodiment of the invention. The rope 6 in hoist output engages around a pulley 7 having a notched crown at its periphery. A flange 8 is articulated around the axis of the pulley and serves as a support for a jamming handle 9. This handle, when actuated clockwise, crushes the rope 6 on the pulley 7. This action makes it possible to pull on the rope 6. To jam the rope 6 when no action is carried out on the handle 9, a cam 10 articulated on an axis 12 crushes the rope 6 against the pulley. This cam rises automatically due to an elastic return means. It is provided with a lug 11 which collaborates with the notches on the periphery of the pulley. This lug 11 will therefore exert a ratchet effect on the pulley 7. But also, it allows the counterclockwise rotation force exerted on the pulley to increase the rise of the cam 10 and therefore amplify the jamming. Conversely, if the pulley 7 is turned clockwise, this releases the cam.

[0050] All this mechanism remains distant from the articulation with the windsurf board here represented by a diabolo (D).

[0051] [Fig.3] shows a sectional view from the left of the same embodiment preferred embodiment of the invention and allows the path of the rope 6 to be visualized as well as the crushing action carried out by actuating the handle 9 via a cam 14 attached to the handle 9. The jamming carried out by the cam 10 and its elastic return means 13 can also be visualized.

[0052] [Fig.4] shows another sectional view but from the right side. We see how the lug 11 collaborates with the notches on the periphery of the pulley 7 in order to create a ratchet effect. We also see that a protrusion 15 on the handle 9 allows the pulley 7 to be driven with the handle 9

[0053] [Fig.5] Shows how the action on the handle 9 by driving the pulley 7 comes to release the cam 10 from the rope 6 by pushing back the lug 11.

[0054] [Fig.6] Shows that the cam can then be completely released by manually pushing back the lug 11. Thus, with the rope 6 wedged by the handle 9 against the pulley 7. The pulley can be allowed to return in an anti-clockwise direction to loosen the hoist by a few notches.

[0055] [Fig.7] shows another way of relaxing. The rope 6 is no longer stuck between the handle 6 and the pulley 7 but the handle 6 is engaged on a notch of the pulley 7. The rope is blocked by manual tension in one of the notches on the periphery of the pulley 7 so that by slightly turning the pulley 7 with the handle 9, the cam is released thanks to its lug 11.

[0056] Rope 6 can then be slowly let out

[0057] [Fig.8] shows how to completely release the rope from the system once the tension is released. From the situation shown in [Fig.7], the rope 6 is shifted into the notch closest to the lug 11. This prevents the cam from returning to press the rope against the pulley 7 and by rotating the pulley counterclockwise, the rope is released.

[0058] [Fig.9] shows the situation of release of the rope resulting from [Fig.8] but can also represent a phase of introduction of the rope if the handle is operated clockwise.

Claims

Claims

1. Mechanical system for managing the tension of a rope which can be integrated into a windsurfing mast foot (Fig. 2 to Fig. 9) and characterized in that the rope (6) circulates between a pulley (7) and a cam (10) which therefore presses the rope against the pulley due to an elastic return means (13) and thus blocks the rope.

2. Mechanical system according to claim 1 characterized in that a handle (9) rotating around the axis of the pulley makes it possible to block the rope (6) against the pulley (7) by a crushing force against the pulley and thus to pull on the rope.

3. Mechanical system according to claims 1 to 2 such that the pulley (7) has notches on its periphery and the cam has a lug (11) which collaborates with these notches for an anti-return action on the pulley but also so that a rotation of the pulley causes a movement of the cam and therefore an additional jamming during a rotation of the pulley in one direction or a release in the opposite direction.

4. Mechanical system according to claim 3 such that the lug (11 Fig. 6) has a shape allowing it to be held by hand away from the notches on the periphery of the pulley (6) so as to keep the cam (10) away from the rope, and also to release the rotation of the pulley.

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