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(11) | EP 1 373 121 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
AUTOMATIC LOCKING DEVICE FOR A LIFTING BLOCK AUTOMATISCHE VERRIEGELUNGSVORRICHTUNG FÜR EINE HEBEVORRICHTUNG DISPOSITIF DE BLOCAGE AUTOMATIQUE D'UN MOUFLAGE DE LEVAGE |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
Technical Field
[0001] The invention relates to a self-locking safety winch. These winches are very often used in building sites and in general in the field of civil and mechanical constructions to raise and lower loads of all types, with manual operation by two operators, one on the ground and the other located at the same height as the winch.
Background Art
[0002] Traditional winches do not have safety devices preventing the load from falling very dangerously to earth in cases where, due to carelessness or physical tiredness or the like, the operator on the ground suddenly loses grip of his part of the rope.
[0003] In some prior art devices this poor safety level has been addressed by including a gearwheel, coaxial to the pulley wheel. A pinion is arranged on the pulley winch, which engages with the gearwheel to lock the winch.
[0004] The main problem with this solution is that the pinion has to be inserted manually between the teeth of the gearwheel and then released as and when needed, and thus not addressing the safety problem as accidental falls due to sudden release of the rope are not dealt with at all. Besides, the pinion insertion-removal operations can be problematic in themselves.
[0005] A further prior art solution is the one illustrated in US-A-4 934 660, which discloses a self-locking safety winch according to the preamble of claim 1.
[0006] The main aim of the present invention is to provide a self-locking safety winch of contained size and weight, as well as being economical.
[0007] A further aim of the present invention is that it provides a self-locking safety winch wherein the braking action is gradual and non-violent and therefore limits wear on the rope, lengthening the working life thereof.
[0008] A further aim of the present invention is to provide a self-locking safety winch which is reliable and safe for operators and third persons, for improving safety at the workplace.
[0009] Finally, a further aim of the invention is to provide a self-locking safety winch which is easy to maintain.
[0010] These aims and more besides are attained by a self-locking safety winch according to claim 1.
Disclosure of Invention
[0011] Further characteristics and advantages of the present invention will better emerge from the detailed description that follows of a preferred but non-exclusive embodiment of the invention, illustrated purely by way of a non-limiting example in the accompanying figures of the drawings, in which:
figure 1 shows a side view of the winch of the present invention, in a position in which the rope is free to run;
figure 2 is the same winch in a position in which the rope is locked;
figure 2a is an enlarged detail of figure 2;
figure 3 is a perspective view of a detail of the locking mechanism of the winch of the present invention.
[0012] With reference to the figures of the drawings, 1 denotes in its entirety a self-locking safety winch according to the present invention.
[0013] The safety winch 1 essentially comprises a disc 1 which rotates about a shaft 4 mounted on a frame 5.
[0015] The frame 5, for compactness and simplicity, as well as for increasing operator safety, is preferably a shaped as a closed box, having one or more upper walls 7, one or more side walls 8 and one or more lower walls 9. On at least one of the lower walls there is at least one opening 10 through which the rope 11 passes into the frame 5.
[0016] The frame 5 is normally provided with special means for suspending 6 for mounting the winch 1 on a suitable support structure (not illustrated in the figure), fixed or mobile depending on the operator's choice. In the simplest embodiment, this means for suspending 6 can be a hook 6a fixed to the upper wall 7 of the frame 5.
[0017] The rope 11 obviously exhibits two ends: one end is the pull end 12 which is generally manoeuvred by the operator located on the ground, and the other end is the load end 13 to which the load to be raised or lowered is secured.
[0018] The means for locking 14 are mounted on the frame 5 of the winch 1 at the disc 2 position, and are operatively active on the rope 11 on the pulling end 12; the means for locking comprise at least one fixed element 14a constrained to the frame and at least one mobile element 14b.
[0019] The fixed element 14a, in a preferred and non-exclusive embodiment, exhibits a cylindrical conformation and can also comprise a special gullet around its circumferential surface.
[0020] The mobile element 14b operates between a near position hard by the fixed element 14a, in which the rope 11 is locked between the fixed element 14a and the mobile element 14b, and a distanced position away from the fixed element 14a, in which the rope is free to run. The mobile element 14b, in a preferred and non-exclusive embodiment, is wedge-shaped and comprises a flat contact surface 15 positioned on the same side as the rope and on the opposite side with respect to the disc 2. The contact surface 15 is provided with an inclined end 18 so as better to engage the rope 11 during the locking phase.
[0021] The mobile element 14b also comprises a curved guide surface 19 located on the same side as the disc 2 and on the opposite side with respect to the rope 11, so as better to suit the profile of the circumferential surface of the disc 2, for example so that it can insert in the gullet 3 of the disc 2. The mobile element 14b also exhibits, on the guide surface 19, a longitudinal slot 16 which engages on a fixed pivot 17 mounted on the frame 5.
[0022] The above-described characteristics enable the mobile element 14b to move, with respect to the fixed element 14a, between a distanced position and a near position, and vice versa.
[0023] In a case of sudden release of ground-based operator's pull on the rope 11, the dragging of the rope 11 against the contact surface 13 of the mobile element 14b moves the mobile element 14b by friction towards the fixed element 14a.
[0024] The rope 11 is therefore blocked between the mobile element 14b and the fixed element 14a, and the load on the load side 13 of the rope 11 cannot fall dangerously to earth.
[0025] To unlock the winch 1, it is sufficient slightly to move the operator pull end 12 of the rope 11 externally, i.e. away from the disc 2 (as shown in figure 1). The rope 11 releases the contact surface 15 of the mobile element 14b, which distances from the fixed element 14a and returns into the unlocked position by forced of gravity.
a frame (5);
a shaft mounted on the frame (5);
a disc (2) rotatably mounted on the shaft (4);
a rope (11) supported by the disc (2) and having a pull end (12) and a load end (13) opposite to the pull end (12); and
means for locking (14) mounted on the frame (5),
wherein:the means for locking (14) comprise a fixed element (14a) solidly constrained to the frame (5) and a mobile element (14b) which operates between a near position to the fixed element (14a) in which the rope (11) is locked between the fixed element (14a) and the mobile element (14b) and a distanced position from the fixed element (14a) in which the rope (11) is free to run;
the mobile element (14b) comprises a contact surface (15) located on a same side as the rope (11) and on an opposite side from the disc (2), and a guide surface (19) located on a same side as the disc (2) but an opposite side from the rope (11); characterised in that
the mobile element (14b) affords a longitudinal slot (16) along the guide surface (49) thereof, the longitudinal slot (16) being engaged with a fixed pivot (17) mounted on the frame (5), in order to enable a displacement of the mobile element (14b).
- einen Rahmen (5);
- eine an dem Rahmen (5) montierte Welle;
- eine drehbar auf der Welle (4) montierte Scheibe (2);
- ein von der Scheibe (2) gehaltenes Seil (11) mit einem Zugende (12) und einem Ladeende (13) entgegengesetzt von dem Zugende (12); und
- Sperrmittel (14), die an dem Rahmen (5) montiert sind,
bei welcher die Sperrmittel (14) ein feststehendes Element (14a) enthalten, das fest mit dem Rahmen (5) verbunden ist, und ein bewegliches Element (14b), welches zwischen einer Position dicht an dem feststehenden Element (14a), in welcher das Seil (11) zwischen dem feststehenden Element (14a) und dem beweglichen Element (14b) blockiert ist, und einer von dem feststehenden Element (14a) abstehenden Position, in welcher das Seil (11) frei ablaufen kann, arbeitet; wobei das bewegliche Element (14b) eine Kontaktfläche (15) enthält, angeordnet auf derselben Seite wie das Seil (11) und auf der entgegengesetzten Seite von der Scheibe (2), sowie eine Führungsfläche (19), angeordnet auf derselben Seite wie die Scheibe (2), aber auf der entgegengesetzten Seite von dem Seil (11); dadurch gekennzeichnet, dass das bewegliche Element (14b) einen Längsschlitz (16) entlang seiner Führungsfläche (19) aufweist, wobei in den Längsschlitz (16) ein feststehender Zapfen (17) greift, der an dem Rahmen (5) montiert ist, um eine Verschiebung des beweglichen Elementes (14b) zu ermöglichen.- un châssis (5);
- un arbre monté sur le châssis (5);
- un disque (2) monté pivotant sur l'arbre (4);
- une corde (11) supportée par le disque (2) et ayant une extrémité de traction (12) et une extrémité de charge (13) opposée à l'extrémité de traction (12); et
- des moyens de blocage (14) montés sur le châssis (5), dans laquelle:
les moyens de blocage (14) comprennent un élément fixe (14a) solidaire du châssis (5) et un élément mobile (14b) qui opère entre une position rapprochée à l'élément fixe (14a), dans laquelle la corde (11) est bloquée entre l'élément fixe (14a) et l'élément mobile (14b), et une position éloignée de l'élément fixe (14a) dans laquelle la corde (11) est libre de coulisser;
l'élément mobile (14b) comprend une surface de contact (15) disposée du côté de la corde (11) et du côté opposé au disque (2), et une surface de guidage (19) disposée sur le côté du disque (2) mais sur un côté
opposé à la corde (11);
caractérisée en ce que l'élément mobile (14b) présente une fente longitudinale (16) le long de sa surface de guidage (19), la fente longitudinale (16) étant engagée par un pivot fixe (17) monté sur le châssis (5), de manière à permettre un déplacement de l'élément mobile (14b).