Device for limiting the rotational range of a swiveling arm

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a device for limiting the rotational range of a swiveling arm, formed by elements arranged and assembled so that they allow a continuous adjustment of the limits of the rotational range of a mechanical arm, for example a swiveling jib crane.

DESCRIPTION OF THE PRIOR ART

[0002] Devices for limiting the rotational range of a swiveling jib crane are known in the art. The devices according to the prior art are identified as described below, according to their spatial configuration.

[0003] There are devices for limiting the rotational range of a swiveling jib crane, which are placed directly on the structures that can potentially interfere with the angular range of the jib, namely they are not part of the structure of the crane itself, but they are positioned out of it. Such limiting devices placed directly on the potentially interfering structures, are generally formed by elements realized and assembled in the place of installation, arranged according to the specific need for angular limitation of the swiveling arm, for example attached to external structures, such as a wall or the like. For this type of limiting devices, the modification of the rotational range is complex, and requires moving elements that cannot be easily adapted to different configurations. Furthermore, this type of limiting devices cannot be reused, in the case of a change in the operating needs related to the rotational range.

[0004] Furthermore, there are devices for limiting the rotational range of a swiveling jib crane, which are placed directly on board of the crane, generally made by elements that are specifically realized each time and/or assembled in the place of installation, according to the specific angular limitation needed for the swiveling arm. Said devices, however, are not adapted to vary the limiting angle of the rotation of the arm and to be used in different configurations, unless an expensive structural modification is performed when needed. The application of such devices requires complex, and sometimes dangerous, operations for their installation and/or their adaptation, to be performed at elevated heights.

[0005] Devices for limiting the rotational range of a swiveling jib crane placed on board of the crane are also conceived to define the rotation of the arm within predefined or preordained ranges. The document JP 55 125298 U of Mitsubishi Electric Corporation refers to a device for limiting the rotational range of a swiveling jib crane, wherein contrast elements fixed to a swiveling element are adapted to abut on fixed abutments, thus limiting the rotational range within predetermined and fixed angles. The geometry of said devices, however, does not allow a continuous and subsequent adjustment of the rotational range of the arm, thus limiting the use of the arm jib within imposed, and not preferential/discretionary, limits.

[0006] The devices known in the art have also criticalities deriving from the fact that it is often difficult and expensive to evaluate the suitability and the resistance of the swiveling structure in which they are used. Furthermore, since the known devices are often manufactured directly by the installer and/or the purchaser, the manufacturer of the crane is not responsible for any possible damage deriving from their defects.

SUMMARY OF THE INVENTION

[0007] The main purpose of the present invention is to solve the drawbacks of the devices for limiting the rotational range of a swiveling arm of the type known in the art.

[0008] In the scope of this purpose, the aim of the present invention is to provide a device for limiting the rotational range of a swiveling arm, which allows a continuous adjustment of said range, in order to provide a swiveling arm, for example of a jib, which operates within preferred limits or limits imposed by potential interferences.

[0009] These tasks are achieved by a device for limiting the rotational range of a swiveling arm as it is described in the attached claims, which form an integral part of the present description. The present invention refers also to a respective lifting or handling device having a swiveling arm, such as a jib crane.

[0010] In particular, the device for limiting the rotational range of a swiveling arm according to the present invention comprises a reaction element on which the constraining elements or limiting elements are attached by means of mobile junctions; these actually realize the limitation of the angular range of the arm, interfering with the structure of a fixed element.

[0011] The reaction element is integral with the rotating elements of the jib, for example with the sleeve of the jib, and thus it rotates integrally with them. At least a limiting element is placed and clamped on said reaction element by means of a mobile junction (for example a pair of jaws joined by bolts), such limiting element being configured, for example, as a small arm, as to delimit the rotational range of the jib.

[0012] Said limiting elements are placed in a circumferential way on the reaction element, so as to determine the angle according to which the rotational range of the jib will be preferably limited. Also said elements, once placed and reversibly constrained, are integral with the reaction element.

[0013] The circumferential positioning of said limiting elements is free, up to the user's choice, and is not fixed in unchangeable positions. A circumferential guide, either projecting or in negative, realized on the reaction element cooperates to orientate and to facilitate the positioning of the limiting elements, and the clamping of the latter takes place by means of a mobile junction. Furthermore, said circumferential guide prevents unwanted movements of the limiting elements, while transmitting the force generated by the collision between them and the fixed element, placed, for example, on the non rotating part of the crane or outside it; such force is amplified by the bending moment transmitted by the mechanical arm, which in a jib can exceed a force of 2500 Kg.

[0014] The limiting elements are preferably shaped so that they can house bumpers made of elastic material, which absorb the energy generated by the forces due to the collision. All these elements are dimensioned so that they can withstand the forces generated by the collision between the limiting elements and the fixed contrasts, in the moment wherein the rotational motion of the arm arrived at the end of the range is stopped; thus there is no need for additional tests aiming to check the suitability of the structural elements.

[0015] Thus the present invention realizes a combination of technical innovation and inexpensiveness, ensuring both an accurate and precise adjustment of the operating limits or the rotation of an arm, for example the arm of a jib, and an increase in safety and inexpensiveness, since additional and expensive structural tests and checks following the installation of the device, are no longer necessary.

LIST OF THE FIGURES

[0016] Further characteristics and advantages of the present invention will become clearer from the following detailed description, which is merely illustrative and non-limitative, and shown in the attached figures, in which:

• figure 1 shows an example of installation of the device for limiting the rotational range on a jib crane;
• figure 2 shows a perspective view of an embodiment of the device for limiting the rotational range of a swiveling arm according to the present invention, in assembled configuration;
• figure 3 shows an exploded view of the device for limiting the rotational range of a swiveling arm of figure 2;
• figure 4 shows a section view, with a middle vertical plane, of the device for limiting the rotational range of a swiveling arm of figure 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0017] The device for limiting the rotational range of a swiveling arm according to the present invention will be now described with particular reference to a preferred embodiment, shown in the attached figures and considered here in a purely illustrative and non-limitative way. The device for limiting the rotational range of a swiveling arm according to the present invention, comprises a reaction element (1) made by a pressed or cast disk-shaped body. Said body is connected in an integral way to the rotating parts (3) of a swiveling jib crane.

[0018] The connection between the rotating parts of the crane and said reaction element can be realized by any means, provided that the transmission of the motion between the former elements and the latter element is ensured. In the example shown, the coupling is realized by a toothed junction (1b), preferably made by broaching.

[0019] Such coupling with toothed junction (1b) allows to configure the limiting device in a reversible way on the swiveling arm; for example if the swiveling arm is electrified by a connection to an electric motor, the limiting device may be no longer necessary, and the respective surface previously coupled with a toothed junction (1b) can be exploited for the aforementioned electrification.

[0020] Circumferential guides or grooves (1a), which represent the area where the limiting elements (2) are placed, are made on the reaction element (1). Each one of the two limiting elements is constituted by two halves connected between each other by means of a mobile junction (4) and tightened on the reaction element (1) at the circumferential groove (1a), so that they reciprocally determine the angle that limits the rotational range of the jib. Between the two halves of the limiting elements, two bumpers (5) made of elastic material are inserted, with the function of absorbing the impact forces between said limiting elements and the fixed parts (6) placed on the fixed part of the swiveling jib or outside it. The fixed element (6) is preferably integral with the vertical rod of the jib, as shown in figure 1.

[0021] The clamping provided by the mobile junction (4) generates a compression force which, by friction, blocks each limiting element (2) in the circumferential position desired on the discoid reaction element (2). The circumferential groove (1a), apart from guiding the positioning of the limiting elements (2) in any circumferential position, works as an aid for blocking the latter, working as a further abutment and constraint in order to prevent circumferential or radial displacements of the limiting elements (2) following the collisions.

[0022] Considering the present description it will be apparent to the person skilled in the art that further variants and modifications are possible, without departing from the scope of the invention as it results from the attached claims.

[0023] The device for limiting the rotational range of a swiveling arm can comprise, for example, a reaction body (1) integral with the rotating parts of a jib crane (3) on which one or more limiting elements (2) are placed in any desired circumferential position, fixed by a mobile junction (4), such one or more limiting elements (2), rotating with the reaction element (1), interfere with a fixed part (6) thus limiting the rotational range of a jib to any desired angle. The limiting device may comprise a reaction element (1) equipped with seats (1a) adapted to guide the positioning of the limiting elements (2) and to ensure, at the same time, a better blocking of the limiting elements (2).

[0024] The limiting device can be equipped with limiting elements (2) realized and shaped so that they can accommodate elastic elements, or bumpers, adapted to absorb the collision forces. The limiting device can anyway be realized with the possibility of positioning one or more limiting elements (2) interfering with a fixed point (6) on a reaction element (1) in any desired circumferential position.

[0025] Although the present invention has been described with particular reference to a swiveling arm of a jib, it can obviously be applied also to other types of swiveling arms, such as robotized arms.

Claims

1. Device for limiting the rotational range of a swiveling arm, comprising a discoidal reaction element (1) adapted to be connected to an element of said swiveling arm so as to integrally turn with said swiveling arm, and further comprising at least a limiting element (2) adapted to cooperate with at least an abutting fixed element (6), characterized in that said limiting element (2) is reversibly constrainable in any circumferential position along the external perimeter of said discoidal reaction element (1), in order to determine a limiting angle of the rotational range of said swiveling arm, wherein said discoidal reaction element (1) comprises an upper face and a lower face, and wherein said limiting element (2) comprises a reversible junction (4) adapted to clamp said upper face and said lower face in a same circumferential position.

2. Device according to claim 1, comprising a pair of limiting elements (2) adapted to reciprocally determine a limiting angle of the rotational range of said swiveling arm, each one of said pair of limiting elements (2) being independently adjustable and constrainable in any circumferential position along said external perimeter.

3. Device according to claim 1 or 2, wherein said discoidal reaction element (1) comprises a circumferential groove (1a) on at least one of said upper face or said lower face, said reversible junction (4) being shaped in such a way as to clamp said circumferential groove (1a).

4. Device according to any one of the claims from 1 to 3, wherein said reversible junction (4) comprises a threaded connection adapted to tighten junction elements against said upper face and said lower face, to clamp them.

5. Device according to claim 4, wherein said reversible junction (4) of said limiting element (2) comprises two junction elements, symmetrical to each other, on which said threaded connection is adapted to act.

6. Device according to any one of the claims from 1 to 5, wherein said limiting element (2) comprises an elastic bumper (5) adapted to abut on said fixed element (6).

7. Device according to any one of the claims from 1 to 6, said discoidal reaction element (1) being adapted to spin around an axis of rotation, central with respect of said circumferential positions.

8. Device according to claim 7, wherein said discoidal reaction element (1) comprises a central toothed hole, adapted to be connected to a respective cylindrical toothed surface of said element of said swiveling arm, so that it turns integrally with said swiveling arm.

9. Apparatus for lifting or handling, comprising a swiveling arm, characterized in that it comprises at least a device for limiting the rotational range according to any one of the claims from 1 to 8.

10. Apparatus according to claim 9, further comprising a support rod for said swiveling arm and an abutting fixed element (6), characterized in that said abutting fixed element (6), adapted to cooperate with said at least a limiting element (2), is constrained on said support rod.

Ansprüche

1. Vorrichtung zum Begrenzen des Schwenkbereichs eines Schwenkarms umfassend ein scheibenförmiges Wirkelement (1), das eingerichtet ist, mit einem Element des Schwenkarms verbunden zu werden, um sich ganzheitlich mit dem Schwenkarm zu drehen, ferner umfassend mindestens ein Begrenzungselement (2), das eingerichtet ist, um mit mindestens einem anstoßstarren Element (6) zusammenzuwirken, dadurch gekennzeichnet, dass das Begrenzungselement (2) lösbar in jeder umlaufenden Position entlang des äußeren Umfangs des scheibenförmigen Wirkelements (1) befestigbar ist, um einen Begrenzungswinkel des Schwenkbereichs des Schwenkarms zu bestimmen, wobei das scheibenförmige Wirkelement (1) eine Oberseite und eine Unterseite aufweist und wobei das Begrenzungselement (2) eine lösbare Verbindungsstelle (4) umfasst, um an der Oberseite und der Unterseite in der gleichen Umlaufposition festzuklemmen.

2. Vorrichtung nach Anspruch 1, umfassend ein Paar von Begrenzungselementen (2), die eingerichtet sind, wechselseitig einen Begrenzungswinkel des Schwenkbereichs des Schwenkarms zu bestimmen, wobei jedes der Begrenzungselemente (2), unabhängig vom anderen, in jeder Umlaufposition entlang des äußeren Umfangs verstellbar und befestigbar ist.

3. Vorrichtung nach Anspruch 1 oder 2, wobei das scheibenförmige Wirkelement (1) eine umlaufende Nut (1a) auf zumindest der Oberseite oder der Unterseite umfasst, wobei die lösbare Verbindungsstelle (4) derartig geformt ist, um ein Festklemmen in der umlaufenden Nut (1a) zu erlauben.

4. Vorrichtung nach einem der vorhergehenden Ansprüche 1 bis 3, wobei die lösbare Verbindungsstelle (4) eine Schraubverbindung umfasst, die eingerichtet ist, die Verbindungselemente gegen die Oberseite und die Unterseite zum Festklemmen zu verspannen.

5. Vorrichtung nach Anspruch 4, wobei die lösbare Verbindungsstelle (4) des Begrenzungselements (2) zwei Verbindungselemente umfasst, die symmetrisch zueinander angeordnet sind, wobei die Schraubverbindung eingerichtet ist, auf die Verbindungselemente zu wirken.

6. Vorrichtung nach einem der Ansprüche 1 bis 5, wobei das Begrenzungselement (2) einen elastischen Puffer (5) aufweist, der eingerichtet ist, an das starre Element (6) zu stoßen.

7. Vorrichtung nach einem der Ansprüche 1 bis 6, wobei das scheibenförmige Wirkelement (1) eingerichtet ist, sich um eine Rotationsachse zu drehen, die zentral im Hinblick auf die Umlaufpositionen ist.

8. Vorrichtung nach Anspruch 7, wobei das scheibenförmige Wirkelement (1) ein zentrales verzahntes Loch aufweist, das eingerichtet ist, um mit einer entsprechend zylindrischen verzahnten Oberfläche des Elements des Schwenkarms verbunden zu werden, um ganzheitlich mit dem Schwenkarm zu drehen.

9. Gerät zum Heben oder Handhaben, umfassend einen Schwenkarm, dadurch gekennzeichnet, dass das Gerät mindestens eine Vorrichtung zum Begrenzen des Schwenkbereichs nach einem der Ansprüche 1 bis 8 aufweist.

10. Gerät nach Anspruch 9, ferner umfassend eine Stützstange für den Schwenkarm und ein anstoßstarres Element (6), dadurch gekennzeichnet, dass das anstoßstarre Element (6) eingerichtet ist, mit mindestens einem Begrenzungselement (2) zusammenzuwirken, wobei das anstoßstarre Element (6) mit der Stützstange verbunden ist.

Revendications

1. Dispositif pour limiter la plage de rotation d'un bras pivotant, comportant un élément de réaction en forme de disque (1) conçu pour être raccordé à un élément dudit bras pivotant de façon à tourner solidairement avec ledit bras pivotant, et comportant, de plus, au moins un élément de limitation (2) conçu pour coopérer avec au moins un élément de butée fixe (6), caractérisé en ce que ledit élément de limitation (2) est contraint, de façon réversible, dans une position circonférentielle quelconque le long du périmètre extérieur dudit élément de réaction en forme de disque (1), en vue de déterminer un angle de limitation de la plage de rotation dudit bras pivotant, dans lequel ledit élément de réaction en forme de disque (1) comporte une face supérieure et une face inférieure, et dans lequel ledit élément de limitation (2) comporte une jonction réversible (4) conçue pour bloquer ladite face supérieure et ladite face inférieure dans une même position circonférentielle.

2. Dispositif selon la revendication 1 comportant une paire d'éléments de limitation (2) conçus pour déterminer mutuellement un angle de limitation de la plage de rotation dudit bras pivotant, chaque élément de ladite paire d'éléments de limitation (2) pouvant être réglé de façon indépendante et contraint dans une position circonférentielle quelconque le long dudit périmètre extérieur.

3. Dispositif selon la revendication 1 ou 2, dans lequel ledit élément de réaction en forme de disque (1) comporte une gorge circonférentielle (1a) sur au moins l'une de ladite face supérieure ou de ladite face inférieure, ladite jonction réversible (4) étant configurée de manière à bloquer ladite gorge circonférentielle (1a).

4. Dispositif selon l'une quelconque des revendications 1 à 3, dans lequel ladite jonction réversible (4) comporte une zone de raccordement filetée conçue pour serrer les éléments de jonction contre ladite face supérieure et ladite face inférieure afin de les bloquer.

5. Dispositif selon la revendication 1 ou 4, dans lequel ladite jonction réversible (4) dudit élément de limitation (2) comporte deux éléments de jonction, symétriques l'un par rapport à l'autre, sur lesquels ladite zone de raccordement filetée est conçue pour agir.

6. Dispositif selon l'une quelconque des revendications 1 à 5, dans lequel ledit élément de limitation (2) comporte une butée en caoutchouc (5) conçue pour buter contre ledit élément fixe (6).

7. Dispositif selon l'une quelconque des revendications 1 à 6, ledit élément de réaction en forme de disque (1) étant conçu pour tourner autour d'un axe de rotation, central par rapport auxdites positions circonférentielles.

8. Dispositif selon la revendication 7, dans lequel ledit élément de réaction en forme de disque (1) comporte un trou central denté, conçu pour être raccordé avec une surface dentée cylindrique respective dudit élément dudit bras pivotant, de façon à tourner solidairement avec ledit bras pivotant.

9. Système destiné à lever ou à manipuler, comportant un bras pivotant, caractérisé en ce qu'il comporte au moins un dispositif pour limiter la plage de rotation selon l'une quelconque des revendications 1 à 8.

10. Système selon la revendication 9 comportant, en outre, une tige de support destinée au dit bras pivotant et un élément de butée fixe (6), caractérisé en ce que ledit élément de butée fixe (6), conçu pour coopérer avec ledit au moins un élément de limitation (2), est contraint sur ladite tige de support.

Drawing