A load hooking and lifting system

Abstract: A load hooking and lifting system (20), comprising a sling (70), which guarantees the hold during the lifting and movement operations of the loads and a connecting rod (40), having the fulcrum at one of its ends (41) on the sling (70) and being kept integral with a lifting hook (50), belonging for instance to a crane, which is positioned at the other end (42). A holding element (30) of the hook (50) prevents the accidental fall of the slung load and allows the release of the sling (70) only in case that the load is placed on a surface.

Description: The present invention refers to a load hooking and lifting system, utilised, in particular in the industrial plants for the production and processing of metal parts. In the steel mills and in the foundries, a sling is used to lift and also to move heavy loads, said sling wraps completely the object in order to guarantee a safe hold and to avoid accidents during the whole operation. A hook of a crane is, then, fixed to a rope of the sling, so that the operator, while working in the crane cab, can lift and move the load in every direction. It is clear that, in such case, any jolts of the load, due to bumps during the lifting or the handling operation, or to an unexpected manoeuvre by the operator can cause the release and the fall of the load, with consequences which can be very dangerous both for the machines and for the machine operators close to the crane. In order to overcome said disadvantage, gravity or spring lever systems are further used, said systems require the presence of a second operator (besides the crane operator) to hook or release a rope of the sling to the crane arm. However, there are specific plant situations (especially in the steel mills and in the foundries), wherein several lifting operations of extremely heavy loads are needed, using specific equipment, inside polluted environments; in these cases, it would be better to reduce the operator exposure to environmental risks. Further also the current safety rules prohibit the presence of operators on the ground during working operations in polluted environments; the stoppage of the plant is mandatory in case that the operator intervention on the machines is needed (due to malfunctions or failures). A system as described in EP 561 751 A, which discloses a load hooking and lifting system according to the preamble of claim 1, is able to overcome the above mentioned disadvantages, and to provide a hooking, lifting and release system of slung loads and of other specific equipment with the operator inside a crane cab, and without any operator on the ground. This system is a hooking and lifting system for slung loads which avoids the accidental release of the load sling from the lifting hook, due to accidental jolts, bumps or to unexpected manoeuvres of the crane operator. A purpose of the present invention is to indicate a load hooking and lifting system, whereby its realisation does not require the use of expensive materials and/or of complex technologies. This and other purposes are achieved through the realisation of a load hooking and lifting system according to claim 1. The system of the present invention realises a safety connection between the lifting hook of a crane and a sling, and the crane operator works inside the crane cab, without any intervention by outside operators on the ground, both to hook and to release the loads. This system allows to work with an open hook, without the need to have a gravity or spring type hook; the crane operator needs to wilfully manoeuvre the crane hook in order to release the load, whilst accidental jolts, bumps or unexpected manoeuvres do not cause the fall of the load. The hooking and lifting system comprises a connecting rod, pivoted on the lifting sling of the load; when said connecting rod is horizontally positioned, it allows the engagement of the crane hook, and, when said connecting rod is vertically positioned in the locking position, it locks in place the crane hook. In fact, in order to release the load, it is necessary to execute a downward manoeuvre of the crane arm, whereby the run length is substantially longer than the usual handling of the load. The features and the advantages of a load hooking and lifting system, according to the present invention, will be better understood from the following description of a non limiting example, referred to the attached drawings, in which: Figure 1 is a partial front view of a load hooking and lifting system, according to the present invention, in its hooking or release position; Figure 2 is a partial front view of a load hooking and lifting system, according to the present invention, in its lifting position. With reference to the figures, the load hooking and lifting system is generally indicated by numeral 20, said system comprises a sling (indicated by numeral 70), which holds safely and steadily the load, a connecting rod 40, pivoted to the sling 70 of the load at one of its ends 41 and a hook 50 to lift the sling 70. The lifting hook 50 is pivotally connected to a pulley 65 and it is fixed to a handling equipment (e.g. a bridge crane) by means of a rope 72; alternatively, the lifting hook 50 is located at one end of a crane arm (not shown) and it is driven by an operator inside the crane cab. The hook 50 engages on a projection 43 of the connecting rod 40, said projection is provided at the end 42, which is opposite to the end 41 whereto the load sling 70 is pivotally connected. Finally, numeral 30 indicates a metallic element which extends from the surface of the connecting rod 40, in order to hold the hook 50 in its lifting position of the load. The hooking and lifting system 20, according to the invention, works substantially as follows: the load hooking operation is executed when the connecting rod 40, whereto the sling 70 is fixed, reaches a substantially horizontal position (as shown in Figure 1) in relation to the end 41; then, the crane operator, working inside the crane cab, puts the curved surface of the hook 50 in contact with the walls of the projection 43, at the end 42 of the connecting rod 40, in order to guarantee the hold. Then, by lifting the hook 50 upward (by means of the rope 72 belonging to a bridge crane or of the crane arm action), the connecting rod 40 reaches a vertical position and becomes the connecting element between the lifting means 50 and the sling 70 which holds the load; in this position, the load can be lifted and moved, in any direction, without causing the release and accidental fall of the load, as a consequence of accidental jolts of the lifting equipment or bumps of the load, due to sudden movements or to sudden or unexpected manoeuvring. A holding metallic element 30 is provided, said element extends from the surface of the connecting rod 40 and holds the hook 50 against the walls of the projection 43 and avoids the release of the hook; in fact, a downward movement of the hook 50 is held by one of the surfaces of the element 30, which is formed by a strap of metallic material applied across the direction of the longest dimension of the connecting rod 40 and which is positioned close to the curved portion of the hook 50. In order to release the sling 70, it is necessary to tilt again the connecting rod 40 until it reaches the horizontal position and to execute a downward run of the hook 50 much longer than in a normal handling of the load during the lifting and movement phases; the horizontal position of the connecting rod 40 can be reached again without the help of operators on the ground, just by putting the load in contact with a surface: in this position, the hook 50 can be easily released from the walls of the projection 43 through a downward movement of the crane arm or of the bridge crane. The features, as well as the advantages, of the load hooking and lifting system, which is the object of the present invention, are clearly defined by the above description. In particular such features and advantages are indicated by the possibility of: avoiding the accidental release of the load during the lifting and movement operations; releasing the sling only in the case that the load is in contact with a surface; hooking or releasing, without the risk of falls, specific equipment (cranes, bridge cranes) from heavy loads through remote control by a crane operator, without any help from operators on the ground. Finally, it is possible to introduce changes to the shown embodiment of the invention, without leaving the basic principles of the innovative idea, as well as it is possible, in the embodiment of the invention, to choose materials and dimensions according to the technical needs.

Claims: A load hooking and lifting system (20) utilised, in particular, in industrial plants for the production and processing of metals, said system being of the type that comprises at least a device (50, 65, 72) for moving the loads and a sling (70) and which guarantees the hold of the loads during the handling operations, characterised by further comprising at least one connecting rod (40), having the fulcrum at its first end (41) on said sling (70) and being kept integral, at its second end (42), with said device (50, 65, 72) for moving the loads, said device (50, 65, 72) comprising at least a hook (50), which is held in the lifting position of the loads by at least an element (30) extending from the surface of the connecting rod (40), said hook (50) engaging at least a projecting portion (43) of the connecting rod (40), said projecting portion (43) being positioned on said second end (42) of the connecting rod (40), and said element (30), which extends from the surface of the connecting rod (40), being positioned close to said second end (42), so as to hold said hook (50) engaged to said projecting portion (43) of the connecting rod (40) during the load lifting and movement operations. A hooking and lifting system (20) according to claim 1, characterised in that said connecting rod (40) is in a horizontal position during hooking or release of the loads from the device (50, 65, 72) used for handling the loads. A hooking and lifting system (20) according to claim 2, characterised in that the load release is allowed only when the load is in contact with a horizontal surface. A hooking and lifting system (20) according to claim 1, characterised in that the connecting rod (40) is in a vertical position during the lifting and the movement of the loads.

Inventors: JUCHEM YVAN, JUCHEM, YVAN
Applicants: LANGONNAISE S A H, LANGONNAISE S.A.H.
Application year: 1998
Main classification: B66C1
IPC codes: B66C1