METHOD FOR HANDLING A LOAD BODY WITH A HOOKLIFT AND A HOOKLIFT

TECHNICAL FIELD RELATING TO THE INVENTION

The object of the invention is a method for handling a load body with a hooklift and a hooklift according to the preambles of the independent claims presented below.

PURPOSE AND DESCRIPTION OF THE INVENTION

The purpose of this invention is to reduce or even completely eliminate problems related to prior art.

The purpose of this invention is to reduce the friction and noise, which during the horizontal movement is generated between a load body and load body supports or the like, and the wear of the parts, which is caused by the friction.

The purpose of this invention is to reduce said friction without a compensating cylinder and other additional devices.

In order to realise for instance the above-mentioned purposes, the method for handling a load body with a hooklift and the hooklift according to the invention are characterised by what is presented in the characterising parts of the enclosed independent claims.

The embodiments mentioned in this text relate, where applicable, both to the method for handling a load body with a hooklift and to the hooklift according to the invention, even though it is not always specifically mentioned.

In a typical method according to the invention for handling a load body with a hooklift,

- the load body is held in the transport position on the load body supports arranged in connection with a frame, - relief of the load body is performed by lifting the load body off from the connection with said load body supports, so that the load body is supported mainly on the relief support member and the rear support member arranged in connection to the second end of the frame,

- the load body is moved substantially in the horizontal direction in such a way that the load body is mainly detached from the load body supports situated in connection with the frame,

- the relief of the load body is performed automatically, using the main cylinder of the hooklift.

By frame is in this application meant mainly a subframe. In an embodiment a rear frame is also arranged in connection with the frame, which rear frame is presented in some of the figures in this application.

By relief of the load body is meant the lifting of the load body off from the connection with the load body supports in such a way that the weight of the load body is not substantially directed towards the supports in question. By load body supports is not meant the rear support member, such as the rear roller, or the relief support member.

According to an embodiment the load body supports are attached in connection with the frame, i.e. the subframe of the hooklift.

By transport position is meant the position, which the load body is ordinarily held in for example when driving.

By performing the relief of the load body automatically is meant that the relieving is programmed to occur automatically, when the load body is transferred from the transport position substantially in the horizontal direction towards the

rear end of the vehicle, and respectively when the load body is transferred substantially in the horizontal direction from the direction of the rear end of the vehicle towards the front end, back into the transport position.

According to an embodiment of the invention the relief of the load body is performed using the PLC technique. With the aid of the PLC technique the relief of the load body can be programmed to occur automatically in connection with the transfer of the load body, preferably prior to the horizontal movement.

According to an embodiment of the invention the rear support member is a rear roller. According to a preferred embodiment there are two rear rollers and they are arranged in connection with the rear part of the subframe. The rear support member can also be arranged in connection with the rear frame.

When the relief of the load body is performed using a main cylinder, the hookarm-middle frame combination is preferably moved with the aid of the main cylinder so that the hookarm-middle frame combination lifts the load body off from the connection with the load body supports. When the load body is moved back into the transport position and the horizontal movement of the load body towards the front end of the vehicle is completed, the effect of the main cylinder and thus of the hookarm-middle frame combination for supporting the load body is terminated, whereby the load body, supported by the load body supports, settles into the transport position.

According to an embodiment of the invention the relief support member is arranged to move with the hookarm-middle frame combination and/or the main cylinder. By hookarm-middle frame combination is meant the hookarm and the middle frame. According to an embodiment of the invention the relief support member is a roller, wheel or other rotating member.

According to an embodiment of the invention the load body is in the transport position mainly detached from the relief support member. According to an embodiment the relief support member, for example the roller in connection with

the middle frame or the hookarm-middle frame combination, is in the transport position held lower than the load body supports, whereby the weight of the load body is directed towards the load body supports.

According to an embodiment of the invention, when performing the relief of the load body, the load body is lifted off from the connection with said load body supports by 0.1 - 30 cm, according to a second embodiment by 0.5 - 20 cm and according to a third embodiment by 1 - 10 cm. The middle frame of the hooklift may thus turn around its attaching axis for example 0.5 - 15 degrees or 1 - 10 or 1 - 5 or 1 - 3 degrees.

According to an embodiment of the invention, after the transport position the relief of the load body is performed prior to the horizontal movement of the load body and/or in the initial stage of the horizontal movement.

Above the method is described mainly starting from the transport position. Having read this application, someone skilled in the art will understand that the stages of the method according to the invention are meant to be performed also in the reverse order, whereby the horizontal movement occurs first from the rear end of a vehicle towards the front end so that the load body is relieved in a manner according to the invention. In this case the relief is terminated after or at the end stage of the horizontal movement, i.e. the load body is lowered onto the load body supports, whereby the transport position is reached.

A typical hooklift according to the invention comprises

- a frame,

- a middle frame, which is arranged by its first end via an axis member in a tumable manner in connection with the frame,

- a hookarm, in connection with the second end of which is arranged a hook member and the first end of which is arranged at least partly inside the middle frame or vice versa, in such a way that the hookarm can be moved in a telescopic manner in relation to the middle frame,

- at least one main cylinder, which by its first end is arranged via an axis member in a turnable manner in connection with the frame, and by its second end in a turnable manner in connection with the middle frame

- at least one load body support, which is arranged in connection with the frame, i.e. typically with the subframe

- at least one rear roller element, such as a rear roller, in connection with the second end of the frame

The hooklift comprises a program, with the aid of which the load body is automatically relieved in connection with the horizontal movement.

According to an embodiment the program is carried out using the PLC technique.

Especially preferably the hooklift is meant for handling a load, for example handling a load body.

The advantage of the invention as defined in the independent claims, is that with its aid the friction and noise, which during horizontal movement is generated between the load body and the load body supports or the like, as well as the wear of the parts caused by the friction, can be automatically reduced.

An advantage of the invention is that with its aid said friction can automatically be reduced using a main cylinder, without a compensating cylinder and other additional devices.

With the aid of the invention the costs of acquiring, installing and servicing a compensating cylinder are avoided, and at the same time more free space is left in connection with the hooklift.

An advantage of the invention is that with its aid the load body can be relieved and positioned with more precision than before in the optimal position, especially for the duration of the horizontal movement.

BRIEF DESCRIPTION OF THE FIGURES

The invention is described in more detail below with reference to the enclosed schematic drawing, in which Figure 1 shows a hooklift according to the first embodiment of the invention, Figure 2 shows a hooklift according to the second embodiment of the inventtion and a load body arranged in connection with it in the transport position, Figure 3 shows a situation, where the main cylinder of the hooklift has been used according to the third embodiment of the invention, Figure 4 shows a situation, where the load body has been moved by the horizontal movement, and

In Figure 5 the main cylinder of the hooklift has been used to tilt the load body remarkably more.

DETAILED DESCRIPTION OF THE EXAMPLES OF THE FIGURES

Figure 1 shows a hooklift according to the first embodiment of the invention. The hooklift comprises a frame 9 and a middle frame 4, which by its first end 4a is arranged via an axis 10 in a turnable manner in connection with the frame 9. As an extension of the middle frame 4 there is a hookarm 7, in connection with the second end 7b of which is arranged a hook member 8 and the first end 7a of which is arranged at least partly inside the middle frame 4 in such a way that the hookarm 7 can be moved in a telescopic manner in relation to the middle frame 4. The hooklift has two main cylinders 2, which by their first end 2a are arranged via an axis 11 in a turnable manner in connection with the frame, and by their second end 2b in a turnable manner in connection with the middle frame 4. In connection with the frame of the hooklift in the Figure there are four load body supports 3, three of which can be seen in the Figure. In connection with the second end 9b of the frame of the hooklift there are two rear rollers 6.

Figure 2 shows a hooklift according to the second embodiment of the invention and a load body 1 arranged in connection with it in the transport position. The load body 1 lays steadily in connection with the hooklift in such a way that its

weight is mainly on the load body supports 3 and rear rollers 6. In the situation in the Figure the weight of the load body 1 is not substantially directed towards the rollers 5 of the middle frame, i.e. towards the relief support members of this example.

Figure 3 shows a situation where, compared to the situation in Figure 2, the main cylinder 2 of the hooklift has in accordance with the third embodiment of the invention been used to such an extent that the load body 1 has been lifted off from the connection with the load body supports 3 by a few centimetres. In the situation in the Figure the weight of the load body 1 is directed mainly towards the rollers 5 of the middle frame, i.e. the relief support members, and towards the rear rollers 6, but at least not substantially towards the load body supports 3.

In the situation shown in Figure 4 the load body 1 has, as compared to the situation in Figure 3, been transferred by horizontal movement in the direction of the arrow 31 away from the first end 9a of the frame of the hooklift, typically this direction is away from the front end of the vehicle in the direction of the rear end. The horizontal movement has been performed by moving the hookarm 7 in the manner of a telescope in relation to the middle frame 4, substantially in the direction of the arrow 31. The load body 1 is still lifted up off the load body supports 3 by a few centimetres with the aid of the main cylinder 2, in such a way that the weight of the load body is directed mainly towards the rollers 5 of the middle frame, i.e. the relief support members, as well as towards the rear rollers 6 situated in connection with the second end 9b of the frame.

In Figure 5 the main cylinder of the hooklift has, as compared to the situation in Figure 4, been used to tilt the load body 1 remarkably more than in the situation in Figure 3, in such a way that the middle frame-hookarm combination 12 has been turned around the attaching axis 10 of the middle frame with about 40 degrees clockwise, as seen from the direction of Figure 5.

Based on what has been presented in the application, it will be clear to someone skilled in the art that the method and the hooklift presented in the application are meant for handling a demountable load body of a vehicle in connection with a vehicle.

The invention is not meant to be limited to the embodiments shown as examples above but, on the contrary, the aim is to interpret it extensively within the scope of protection defined in the claims below.