[0001] The present invention refers to a load hooking and lifting system, utilized, in particular
in the industrial plants for the production and processing of metal parts.
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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).
[0007] A purpose of the present invention is to realize a load hooking and lifting system
able to overcome the above mentioned disadvantages, and to indicate 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.
[0008] Another purpose of the present invention is to indicate 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.
[0009] A further purpose of the present invention is to indicate a load hooking and lifting
system, whereby its realization does not require the use of expensive materials and/or
of complex technologies.
[0010] These and other purposes, according to the present invention, are achieved through
the realization of a load hooking and lifting system according to claim 1, which is
taken as reference.
[0011] The system of the present invention realizes 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
1. A load hooking and lifting system (20), utilized, in particular in industrial plants
for the production and processing of metals, said system is of the type that comprises
at least a device (50, 65, 72) for moving the loads and a sling (70), 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) comprises 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).
2. A hooking and lifting system (20) according to claim 1, characterised in that said
hook (50) engages at least a projecting portion (43) of the connecting rod (40), said
portion (43) is positioned on said second end (42) of the connecting rod (40).
3. A hooking and lifting system (20) according to claim 2, characterised in that said
holding element (30), which extends from the surface of the connecting rod (40), is
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.
4. 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.
5. A hooking and lifting system (20) according to claim 4, characterised in that the
load release is allowed only when the load is in contact with a horizontal surface.
6. 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.