Patent Publication Number: US-10766748-B2

Title: Crane for lifting and transporting loads comprising a roll-over protection system

Description:
This application is a National Stage Application of International Patent Application No. PCT/IB2015/056823, filed 7 Sep. 2015, which claims benefit of Serial No. TO2014A000711, filed 11 Sep. 2014 in Italy and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. 
     TECHNICAL FIELD 
     The present invention relates to a crane, or equipment, for lifting and moving loads, equipped with an implemented roll-over protection system. 
     TECHNOLOGICAL BACKGROUND 
     In the industrial field, as well as in the craft industry, the need to pick up, move and position loads, even considerably heavy ones, to/at substantial heights and distances from the pick-up point is well known. 
     However, due to the considerable weight of the load to be moved, as well as the distance between said load and the crane, the crane is in danger of rolling over, consequently posing risks to the people in its vicinity and to the goods. Furthermore, during the moving of loads, there is a high risk of dynamic roll-over due to the abrupt movements of certain parts of the crane itself. 
     Therefore, the need is felt to provide cranes for lifting and moving loads, which are equipped with an implemented roll-over protection system and are able to intervene in a prompt, precise and safe manner. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a crane for lifting and moving loads, equipped with a roll-over protection system, which is able to solve this and other drawbacks of the prior art and which, at the same time, can be produced in a simple and economic fashion. 
     In particular, one of the technical problems solved by the present invention is that of providing a crane for lifting and moving loads, equipped with an implemented roll-over protection system, which is able to intervene in a prompt, precise and safe manner. 
     One particular variant of the invention has the object of providing a crane for lifting and moving loads, capable of performing a wide range of movements. 
     The appended claims are an integral part of the technical teaches provided in the following detailed description concerning the present invention. In particular, the appended dependent claims define some preferred embodiments of the present invention and describe optional technical features. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the present invention will be best understood upon perusal of the following detailed description, which is provided by way of example and is not limiting, with reference, in particular, to the accompanying drawings, wherein: 
         FIG. 1  is a lateral view of a crane according to an embodiment of the present invention; 
         FIG. 2  is a lateral view of a crane according to the invention, shown in different operating conditions; 
         FIG. 3  is a plan view of a crane according to the invention; 
         FIG. 4  is a lateral view of a detail of the crane; 
         FIG. 5  is a plan view of a further detail of the crane; 
         FIG. 6  is a front view of a further detail of the crane; 
         FIG. 7  is a lateral view of a crane according to a further embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the accompanying figures, number  10  indicates, as a whole, a crane for lifting and moving loads, comprising: 
     a base frame  12 , capable of transferring the loads of crane  10  onto a support surface by means of contact means arranged in contact with said surface, such as wheels  14 ; 
     a lifting mechanism to lift and transport loads, associated with said base frame ( 12 ); 
     Crane  10  is also equipped with a roll-over protection system comprising: 
     a first portion ( 36 ) and a second portion ( 38 ) of base frame ( 12 ), mutually hinged to one another, the first ( 36 ) and the second portion ( 38 ) being also constrained by at least one elastic means ( 40 ); and 
     a control system adapted for detecting the mutual position between the first ( 36 ) and the second portion ( 38 ) and of carrying out predetermined tasks of crane ( 10 ) when said mutual position reaches a threshold condition. 
     For greater clarity, a non-limiting description of a crane  10  having a particular structure and a preferred lifting mechanism is provided below. 
     With particular reference to the variant shown in figures from  1  to  6 , crane  10  comprises: 
     base frame  12 ; 
     a sliding element  16  which is constrained to base frame  12  in a sliding manner; 
     an arm  18 , adapted for moving the loads and is hinged to the sliding element  16 ; 
     a connection element  20  having a first end, which is hinged to sliding element  16 , and a second end, which is constrained to base frame  12  in a mobile manner; 
     a pair of rod elements  22 , each rod element  22  being hinged to said base frame  12  and to said connection element  20  so as to form an articulated quadrilateral; 
     a first linear actuator  24 , hinged to base frame  12  and to connection element  20  and s able to cause the sliding movement of sliding element  16  relative to base frame  12 ; 
     a second linear actuator  26 , hinged to sliding element  16  and to arm  18  and is able to cause the mutual rotation movement between arm  18  and sliding element  16 . 
     In a non-limiting manner,  FIG. 1  shows an articulated quadrilateral, which is defined by the points indicated with letters A, B, C, D. 
     In the preferred variant shown in  FIG. 1 , sliding element  16  is adapted to slide substantially vertically. 
     In particular, base frame  12  comprises a pair of uprights  28 , which are provided with guides, on which the sliding element  16  is designed to slide. 
     In the example, arm  18  and sliding element  16  are longitudinal elements; conveniently, they are beam elements, preferably internally hollow. 
     Sliding element  16  is arranged along a substantially vertical line and, in correspondence to its upper end, it is hinged to arm  18 . Therefore, arm  18  and sliding element  16  are suited to mutually rotate. In the preferred example shown, sliding element  16  is able to perform a vertical sliding motion relative to base frame  12 , and arm  18  is able to rotate relative to said sliding element  16 . Consequently, arm  18  is able to perform a rotational-translational motion, thus allowing crane  10  to have ample freedom of movement. 
     With particular reference to the constraint between sliding element  16  and arm  18 , the term “hinged” should not be understood in a limiting way: i.e. sliding element  16  and arm  18  can be connected by means of a through pin, but, alternatively, they can also be constrained by means of any hinge system suited to allow them to mutually rotate. A similar observation applies to the other hinge constraints to be found in crane  10 . 
     Conveniently, arm  18  is telescopic. 
     With reference to a particular variant that is not shown herein, arm  18  is telescopic and comprises three mutually sliding segments, which are controlled by a third linear actuator. The first segment is constrained to the sliding element in a rotary manner, the second segment can slide relative to the first segment, and the third segment can slide relative to the second segment. The third linear actuator is adapted to perform the extraction/retraction of the segments, so as to increase/decrease the reach of arm  18 . In this way, loads can also be moved to considerable distances from the point where crane  10  is located, while ensuring a high degree of compactness of crane  10  itself. 
     Conveniently, hydraulic actuators  24 ,  26 , or at least one of them, are hydraulic jacks mainly consisting of a piston sliding inside a cylinder. 
     Preferably, arm  18  is provided with means for attaching and transporting the loads, such as, for example, a clamp, tongs, a hook  30 , or a platform, etc. 
     For example, arm  18  is associated with a winch system or a hoist, in order to move the loads. Said winch is conveniently activated by a motor means, such as an electric motor. 
     The winch (or hoist) is associated with a hook  30 , or the like, which can be extracted or retracted by operating the winch. 
     According to a variant which is not shown herein, arm  18  comprises a pair of hooks: the first hook is controlled by a winch and is therefore mobile, or extractable, relative to arm  18 ; the second hook, on the other hand, is fixed with respect to arm  18 . In particular, the first and the second hook can be placed on the distal end of the telescopic segment of arm  18 . 
     According to further variants, arm  18  can only be associated with one or more fixed hooks. Furthermore, the point in which the hooks, either fixed or extractable, are associated with arm  18  in the following examples should not be understood in a limiting way. For example, it is possible that the fixed hook is attached to the first or the second segment and is therefore not to be found on the distal end of arm  18 . Furthermore, it is possible to associate the at least one hook with a non-telescopic arm  18  as well. 
     With a non-limiting reference to the variant shown in  FIG. 1 , connection element  20  is manufactured by means of a pair of plates, among which an end of the first linear actuator  24  is hinged (in particular the upper end), and each plate is associated with a respective pair of rod elements  22  so as to create an articulated quadrilateral with the respective plate  20  and base frame  12 . 
     In particular, base frame  12  comprises a pair of uprights  28 , and each upright  28  is connected in a mobile manner to the respective plate  20  by means of the respective pair of rod elements  22 . Therefore, in the example shown, there are two uprights  28  belonging to base frame  12 , two plates making up the connection element  20 , and four rod elements  22 . 
     This preferred embodiment allows some of the mobile elements suited to lift and move the load to partially interlock with each other, thus combining a high load capacity and a wide range of movements in a remarkably compact structure. 
     The lower end of the first linear actuator  24  is hinged to the lower part of base frame  12  and said first linear actuator  24  is mainly located between the two uprights  28 . The first linear actuator  24  is also located between the two pairs of rod elements  22  and between the two plates making up connection element  20 . In this configuration, which represents a preferred non-limiting variant of the invention, crane  10  gains remarkable compactness. 
     Generally, the two plates making up connection element  20  are mutually constrained by means of structural elements such as connection brackets or the like. Conveniently, a tubular element or a pin is fixed between the plates, the upper end of the first linear actuator  24  being pivoted on said tubular element or pin. 
     In the variant shown herein, the two plates  20  are arranged laterally with respect to sliding element  16 , close to the point where they are hinged to said sliding element  16 . 
       FIG. 2  shows a variant of crane  10  in four different operating conditions. 
     In the first operating condition, arm  18  is in a lowered position and is arranged horizontally, and one can see other mobile elements, among which rod elements  22 , connection element  20 , sliding element  16  and linear actuators  24 ,  26 . 
     In the second operating condition, arm  18   r  is in a lowered and inclined position. 
     In the third operating condition, arm  18 ′ is in a lifted position and is arranged horizontally, and one can see other mobile elements, among which rod elements  22 ′, connection element  20 ′, sliding element  16 ′ and linear actuators  24 ′,  26 ′. In this lifted condition, C′ and D′ indicate the points that, together with A and B, make up the articulated quadrilateral. Indeed, points A and B are fixed with respect to base frame  12  (in particular A and B belong to uprights  28 ), while points C, C′ and D, D′ are mobile and represent the point where rod element  22  is hinged to connection element  20 . 
     In the fourth operating condition, arm  18 ′ r  is in a lifted and inclined position. 
     As already mentioned above, in order to move arm  18  from lowered condition ( 18 ,  18   r ) to the lifted one ( 18 ′,  18 ′ r ) and vice versa, the first linear actuator  24  is used; whereas in order to allow arm  18  to tilt, the second linear actuator  26  is used. 
     In the figure,  18   t  schematically indicates the telescopic segment of arm  18 . 
     Preferably, crane  10  comprises a ground drive transmission means to transmit the drive to the ground, which is controlled by a rudder  32 , conveniently a servo-assisted one. The ground drive transmission means can comprise a driving wheel  34 , or a track, or any other means suited to transmit a driving force onto a support surface. For example,  FIG. 6  shows a preferred ground drive transmission means comprising a pair of driving wheels  34 , which are conveniently able to rotate independently of one another. This solution turns out to be particularly advantageous when steering, since the presence of a pair of wheels  34 , compared to a single wheel, brings about a reduction in the friction force arising between wheels  34  and the ground and obstructing the steering. 
     The pair of wheels  34  is supported by a support structure  44  associated with base frame  12  in a rotary manner, in particular it is associated with the first portion  36 . For the sake of simplicity, in the remaining part of the description, reference is made to driving wheel  34 , nonetheless without limiting the inventive concept. 
     The servo-assistance of the steering gear can be of a known type, and it is useful to reduce the force that needs to be exerted by a user who intends to steer the wheel manually by holding the rudder, thus making the crane easier to use, especially when the weight of the crane and of the supported load amounts to a few tons, in which case the friction force of the wheel on the ground would make it difficult for a user to steer only manually. In the example shown in  FIGS. 3 and 6 , on the first portion  36  there is a steering linear actuator  46 , for example a hydraulic jack, which acts upon support structure  44 , allowing it to rotate relative to base frame  12 . Steering linear actuator acts upon support structure  44  by means of a gear  52  which is associated with base frame  12 . Alternatively, steering linear actuator  46  can be directly constrained (in particular by means of a hinge) to support structure  44 ; or it can be connected to support structure  44  by means of further mechanisms. 
     Preferably, rudder  32  is equipped with a plurality of control tools to control the movement of crane  10  and the movements of the “lifting mechanism” comprising arm  18 , sliding element  16 , rod elements  22 , connection element  20 . By using the control tools it is possible to control the activation of linear actuators  24 ,  26 , and, if necessary, of the third linear actuator. By using the control tools it is also possible, if necessary, to control the activation of the means for attaching and transporting the loads, such as extractable hook  30 , etc. 
     The control tools can comprise, for example, push-buttons, levers, screens, warning lights, sirens, indicators of different types, thus allowing the user to receive signals of various kinds regarding the operation of crane  10 . 
     According to a preferred embodiment of the present invention, crane  10  comprises a wireless remote control system, adapted for controlling the movement of arm  18  and/or the movement of ground drive transmission means  34 . In the further advantageous variant in which the remote control system is suited to control both the movement of arm  18  and the movement of driving wheel  34 , the operator can operate in a totally remote manner by remaining at a distance from crane  10  during the movement of the crane itself on the supporting ground, as well as during the moving of the loads. By so doing a higher degree of safety is achieved, due to the fact that the user does not have to remain in contact with crane  10  while performing all the operations anymore, in particular when it is necessary to operate in dangerous situations, such as unsafe environments where there may be falling objects, the presence of high temperature objects, the presence of harmful substances, etc. 
     The roll-over protection system will now be described in detail, with a non-limiting reference to the examples shown and explained herein. 
     As already mentioned above, the control system is capable of detecting the mutual position between the first  36  and the second portion  38  and of carrying out predetermined tasks of the crane when said mutual position reaches a threshold condition. 
     For example, arm  18  of crane  10  is telescopic and, when the mutual position reaches the threshold condition, the control system prevents telescopic arm  18  from extending or moving. 
     With particular reference to figures from  3  to  5 , the roll-over protection system comprises a pair of elastic means (in the example, springs)  40 , each connected to the first  36  and to the second portion  38  of base frame  12 . 
     Preferably, crane  10  comprises at least one sensor (a sensor means, or the like) capable of detecting the mutual position between said portions  36 ,  38 . The at least one sensor is conveniently associated with the first  36  and/or the second portion  38  of the base frame. 
     With reference to the variant shown, a sensor  48  is advantageously used, which is associated with one of said portions (in the example, said sensor is associated with the first portion  36 ) adapted to detect the proximity to or the contact with the other portion (in particular, the second portion  38 ). Sensor  48  is preferably a contact sensor or a proximity sensor (e.g. a photodetector, a sensor of the capacitive, inductive, magnetic, ultrasound or optical type, etc.). 
     On the second portion  38  there is a striker portion  50  adapted to cooperate with sensor  48 , so as to signal the mutual position between the first  36  and the second portion  38 . Alternatively, crane  10  can be provided with further known types of sensors, to be arranged on the first  36  and/or second portion  38  of base frame  12 , designed to detect the mutual position between said portions. 
     According to a particular variant, the detection of the mutual position between the first  36  and the second portion  38  is carried out by means of the detection of the deformation of elastic means  40 . Indeed, since the first  36  and the second portion  38  are constrained by means of at least one hinge (in the figure, number  42  indicates, by way of example, the hinging point, which from now on will also be called “hinge” for the sake of brevity) and at least one elastic means  40 , the deformation of elastic means  40  is linked to the position of the first  36  and second portion  38 , which are capable of rotating around the hinging point  42 . With a non-limiting reference to figures from  1  to  4 , hinge  42  is located in the lower part of base frame  12  and elastic means  40  is located in an upper part; therefore, the two portions  36 ,  38  of base frame  12  are constrained to rotate around hinging point  42 , and said rotation corresponds to a greater or smaller elongation of elastic means  40 . Therefore, by measuring the deformation of elastic means  40 , it is possible to detect the mutual position between the first  36  and the second portion  38 . 
     In general, when the mutual position between the first  36  and the second portion  38  reaches a threshold condition, or a threshold value, the control system can be suited to carry out many and different predetermined tasks, such as for example: stopping one or more linear actuators  24 ,  26 ,  46 ; performing one or more predetermined movements of at least one linear actuator  24 ,  26 ,  46 ; interrupting the operation of driving wheel  34 ; emitting an emergency signal that can be perceived by a user (e.g. light and/or sound signal), etc. 
     In general, the control system can be designed in such a way that, when the mutual position between the first  36  and the second portion  38  reaches a threshold value, every movement of crane  10  that is likely to cause an increase in the rolling-over torque is interrupted or inhibited. The control system can also be designed in such a way that, when the mutual position between the first  36  and the second portion  38  reaches a threshold value, one or more movements of crane  10  that are likely to cause a decrease in the rolling-over torque are carried out. 
     By mere way of example, a description follows of how the roll-over protection system operates with reference to the variant of crane  10  shown. During the load moving operations, telescopic arm  18  supports a load at its ends; depending on the extension of said arm  18 , a rolling-over torque is generated relative to the support base of crane  10 —in the example shown, the support base is made up of the support wheels  14  and driving wheel  34 . Therefore, when the extension of arm  18  generates a rolling-over torque having a limit value, the crane is in danger of rolling over, consequently posing risks to the health of the people in its vicinity, to the integrity of the goods and of the surrounding environment. Based on the rolling-over torque (depending on the weight of the load and the reach of telescopic arm  18 ), the contact means arranged in contact with the support surface (in this specific case, wheels  14  and driving wheel  34 ) generate a constraining reaction with respect to the support surface; as the rolling-over torque changes, the constraining reaction of wheels  14 ,  34  changes accordingly, so as to generate a stabilizing torque which Therefore, based on the constraining reactions of the different contact means, the mutual position between the first  36  and the second portion  38  of base frame  12  will change, since the first and the second portion are mutually constrained by means of a hinge  42  and an elastic means  40 . As a consequence, when the rolling-over torque assumes a predetermined limit value, or a danger one, which corresponds to a mutual position between the first  36  and the second portion  38 , the control system detects said mutual position and, if the mutual position reaches a threshold condition, or a limit or “danger” value, the control system carries out predetermined tasks of the crane. 
     Even if in the example shown the contact means arranged in contact with the surface include wheels  14 ,  34 , it is also possible to use other known contact means, such as a track etc. 
     For example, with reference to the variant shown, when safety conditions are in place the first  36  and the second portion  38  are spaced apart in the area close to elastic means  40 . As the rolling-over torque increases, said portions  36 ,  38  get closer by rotating, thus compressing elastic means  40 , until striker portion  50  touches sensor  48 ; now the control system intervenes by carrying out predetermined tasks of crane  10 , since the mutual position between portions  36 ,  38  has reached the threshold condition. According to a preferred variant, elastic means  40  works in compression. Alternatively, elastic means  40  works in traction. 
     By changing the geometry of crane  10  or of the base frame of crane  10 , the stiffness of elastic means  40 , or by setting sensor  48  or the control system differently, the user can freely define how the roll-over protection system should intervene. 
     Furthermore, as one can clearly understand, the roll-over protection system also intervenes in order to prevent crane  10  from rolling over in dynamic operating conditions, since crane  10 , in order to move the loads, moves its parts and, if necessary, moves along the support surface. 
     Optionally, the control system is capable of detecting the mutual position between the first  36  and the second portion  38  as a variation of said mutual position relative to an initial position in which crane  10  is in a safety condition. If said variation of the mutual position exceeds a predetermined threshold value, the control system carries out predetermined tasks of the crane. For example, it is possible to detect a variation of the deformation of elastic means  40  relative to a predetermined initial deformation corresponding to a safety condition; if said variation of the deformation exceeds a predetermined threshold value, the control system carries out predetermined tasks of the crane. 
     With reference to the example shown, rudder  32  and driving wheel  34  belong to the first portion  36 , while uprights  28 , as well as the lifting mechanism, belong to the second portion  38 . 
     Crane  10  preferably comprises at least one electric battery, which can be of the rechargeable type or not. Conveniently, the battery is rechargeable and can be recharged without being removed from the crane through suitable battery recharging means, for example by connecting the battery recharging means to an industrial or domestic socket outlet. 
     The battery is adapted to supply the power required to carry out one or more of the following operations: activating linear actuators  24 ,  26 ; activating the signaling devices, among which the acoustic and visual ones; supplying power to the control system; activating the ground drive transmission means (e.g. driving wheel  34 ); etc. 
     The roll-over protection system of the present invention can be integrated in many further types of crane, which are equipped, for example, with very different lifting mechanisms. 
       FIG. 7  shows a further variant of crane  10  having a simpler lifting mechanism and comprising: a telescopic arm  18  associated with base frame  12  (in particular with the second portion  38 ) and activated by a further linear actuator  54 . 
     The figure does not indicate the roll-over protection system, however, this should be located (similarly to the embodiment described above) close to the broken line (indicated with letter L) separating the first  36  from the second portion  38  of base frame  12 . 
     According to further variants, arm  18  of crane  10  can be moved by means of a wire rope system, alternatively or in addition to linear actuator  24 ,  26 ,  54 . 
     Naturally, the principle of the present invention being set forth, embodiments and implementation details can be widely changed relative to what described above and shown in the drawings as a mere way of non-limiting example, without in this way going beyond the scope of protection provided by the accompanying claims. 
     KEY TO THE NUMERICAL REFERENCES 
     
         
         crane  10   
         base frame  12   
         wheels  14   
         sliding element  16   
         arm  18   
         connection element  20   
         rod element  22   
         first linear actuator  24   
         second linear actuator  26   
         upright  28   
         hook  30   
         rudder  32   
         ground drive transmission means  34   
         first portion (of the base frame)  36   
         second portion (of the base frame)  38   
         elastic means  40   
         hinging point  42   
         support structure  44   
         steering linear actuator  46   
         sensor  48   
         striker portion  50   
         gear  52   
         further linear actuator  54