FIELD OF THE INVENTION

The present invention relates to a boom launch trailer.

BACKGROUND OF THE INVENTION

When connecting elongated loads such as booms to load receivers such as boom trucks, correct lateral positioning of the boom launch trailer carrying the boom is essential in order for the boom to not have to be rotated continuously in order to correctly position the connection end of the boom as the boom launch trailer reverses and approaches the connection point of the boom truck. Prior art solutions to this include the abovementioned continuous rotation of the boom in order to line up its connection end with the connection point of the boom truck as the boom launch trailer reverses. This is a delicate procedure however, and one that is prone to error. Another solution is to strive to achieve a perfect or near-perfect lateral alignment of the boom launch trailer with the boom truck before connecting the boom thereto. This is difficult and may require several retries before being successful, but rear-view cameras and modem driving aids simplify this operation somewhat.

SUMMARY OF THE INVENTION

It is an object of the present invention to alleviate at least some of the mentioned drawbacks of the prior art and to provide a boom launch trailer capable of more efficiently positioning an elongated load, e.g. a boom, in relation to a load receiver, e.g. a boom truck. This and other objects, which will become apparent in the following, are accomplished by a boom launch trailer as defined in the accompanying independent claim.

The term exemplary should in this application be understood as serving as an example, instance or illustration.

The present invention is at least partially based on the realization that correct lateral positioning of the boom launch trailer is key when using a traditional boom launch trailer to connect at boom to a boom truck. If the lateral positioning is a little bit off, the boom support arrangement needs to constantly reposition the boom as the boom launch trailer approaches the boom truck, in order for the boom to connect correctly to the boom connection arrangement of the boom truck. By being able to reposition the entire boom launch trailer by rotating the trailer frame thereof, the need for boom support rotational correction is reduced or eliminated. This is beneficial as it decreases the time it takes to unload a boom from the boom launch trailer and connect it to a boom truck, and reduces the risk of errors in doing so.

The present invention is furthermore based on the realization that there are other types of elongated loads for which the lateral and/or rotational position of which is important during unloading. The present invention is thus equally applicable in cases where an elongated load needs to be carefully unloaded from a trailer while maintaining a given rotation and position relative to the unit at which the elongated load is unloaded.

According to the first aspect of the present invention, a boom launch trailer is provided. The boom launch trailer comprises: a trailer frame having a vehicle connection arrangement provided at a first end thereof for connection of the boom launch trailer to a vehicle, and a wheel axle provided at an opposite second end thereof, said wheel axle having a pair of wheels for supporting a portion of the boom launch trailer when connected to a vehicle; wherein said boom launch trailer further comprises a boom support arrangement that is connected to the trailer frame and is arranged to support an elongated load; and a rotational adjustment arrangement arranged to adjust a rotational position of said trailer frame about a rotational center that coincides with a permanent or semi-permanent pivot joint thereof.

In the context of the present invention, a vehicle is to be interpreted as meaning for example a semi-truck trailer, and the elongated load is for example a boom.

Furthermore, any spatial references herein are to be interpreted from the perspective of the normal use scenario of the boom launch trailer, i.e. when the wheels are facing towards the ground and a rearmost part of the vehicle pulling the trailer is connected to the vehicle connection arrangement. This means that "up" refers to a direction away from and perpendicular to the ground, and "down " refers to a direction towards and perpendicular to the ground. “Forward” and “backward” are to be interpreted from the orientation of the intended primary direction of travel of the vehicle pulling the boom launch trailer. Finally, the “lateral” directions are those to either side of the boom launch trailer, i.e. perpendicular to up/down-direction and forward/backward- direction. Other spatial references are to be interpreted according to their normal meaning using the above definitions as a frame of reference.

According to one example embodiment, the permanent or semipermanent pivot joint allows rotation of the trailer frame about a vertical axis.

According to one example embodiment, the permanent or semipermanent pivot joint is provided at the vehicle connection arrangement. Alternatively, the permanent or semi-permanent pivot joint is provided rearwards of the vehicle connection arrangement.

According to one example embodiment, the rotational adjustment arrangement is provided at said second end of the trailer frame and comprises a pair of vertically adjustable support legs connected to each other by a connection member.

According to one example embodiment, the permanent or semipermanent pivot joint and the rotational adjustment arrangement are provided on either side of a center of gravity of the boom launch trailer measured in a longitudinal direction a horizontal plane. In other words, the permanent or semi-permanent pivot joint is provided in front of the center of gravity of the boom launch trailer, and the rotational adjustment arrangement is provided rearwards of the center of gravity of the boom launch trailer.

According to one example embodiment, the connection member is slidably connected to the trailer frame such that the lateral position of the pair of vertically adjustable support legs relative the trailer frame may be controlled.

According to one example embodiment, each one of the pair of vertically adjustable support legs comprises a linear actuator having a foot member arranged at the movable end thereof, such that the foot member may be lowered and raised relative the trailer frame by means of the linear actuator.

According to one example embodiment, each one of the pair of vertically adjustable support legs comprises a linear actuator.

According to one example embodiment, each one of the pair of vertically adjustable support legs comprises a foot member arranged at a movable end thereof, such that the foot member may be lowered and raised relative the trailer frame.

According to one example embodiment, each one of said vertically adjustable support legs is a foldable leg mechanism arranged to move a foot member thereof between a raised and a lowered position by means of rotation of at least one link of the foldable leg mechanism.

According to one example embodiment, the vertically adjustable support legs are realized by a pair of support legs connected by a connection member, wherein the vertical position of the foot members of the support legs relative the ground may be controlled by means of the suspension arrangement of the wheel axle at the second end of the boom launch trailer. The suspension arrangement does this by controlling the relative position of the wheels and the support legs between a raised position and a lowered position of the support legs, i.e. by raising and lowering the height of the wheel axle, also known as controlling the ride height.

According to one example embodiment, the foot member is, in a raised position, arranged higher than the lowest part of the pair of wheels of the boom launch trailer, and wherein the foot member is, in the lowered position, arranged lower than the lowest part of the part of wheels of the boom launch trailer, such that the second end of the trailer frame may be lifted relative the ground when the boom launch trailer is connected to a vehicle and the foot member is lowered.

According to one example embodiment, the connection member of the rotational adjustment arrangement is slidably connected to the trailer frame along a circular arc having a radius that is equal to the distance between the connection member and the permanent or semi-permanent pivot joint. According to one example embodiment, the circular arc along which the connection arrangement of the rotational adjustment arrangement is slidably connected to the trailer frame is centered on the permanent or semipermanent pivot joint of the trailer frame.

According to one example embodiment, the connection member of the rotational adjustment arrangement and the trailer frame are connected to each other by means of a linear actuator that is movable between two end states and an intermediate state between said two end states, wherein the first end state is such that the linear actuator is extended to a degree that the rotational adjustment arrangement is moved along said circular arc to a laterally offset first position on a first side of said trailer frame, and wherein the second end state is such that the linear actuator is retracted to a degree that the rotational adjustment arrangement is moved along said circular arc to a laterally offset second position on an second side of said trailer frame that is opposite said first side, and wherein said intermediate state is achieved by the linear actuator being positioned such that the rotational adjustment arrangement is centered relative the trailer frame.

According to one example embodiment, the boom support arrangement is arranged on the same side of the permanent or semipermanent pivot joint of the trailer frame as the rotational adjustment arrangement, measured in a longitudinal direction of the boom launch trailer.

According to one example embodiment, the boom support arrangement is arranged between the rotational adjustment arrangement and the permanent or semi-permanent pivot joint of the trailer frame, measured in a longitudinal direction of the boom launch trailer.

According to one example embodiment, the connection arrangement of the rotational adjustment arrangement is slidably connected to the trailer frame by means of a sliding contact bearing, i.e. two plain surfaces arranged for low friction contact with each other. This may for example be realized by means of a film of lubricant provided therebetween, or simply by having two opposing polished surfaces. According to one example embodiment, the boom support arrangement comprises means for longitudinal adjustment of said elongated load.

According to one example embodiment, the boom support arrangement comprises a rear boom support and a main boom support.

According to one example embodiment, the means for longitudinal adjustment is realized by the rear boom support being slidably connected to the trailer frame and actuated therealong by means of an boom support actuator, and the main boom support being provided with a roller bearing surface on which the elongated load is to be placed, such that the elongated load slides over the main boom support while being supported thereby when the rear boom support is moved along the trailer frame by means of the boom support actuator.

According to one example embodiment, the boom support arrangement comprises a rear boom support and a main boom support, and wherein said means for longitudinal adjustment of said elongated load is provided by the rear boom support and the main boom support both being slidably connected to the trailer frame and at least one of them being actuated therealong by means of at least one boom support actuator, such that the elongated load may be moved in a longitudinal direction by means of the rear boom support and the main boom support sliding along the trailer frame by means of the at least one boom support actuator while the elongated load is supported by the boom support arrangement.

Generally, all terms used in the description are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the [element, device, component, means, step, etc.]” are to be interpreted openly as referring to at least one instance of said element, device, component, means, step, etc., unless explicitly stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will now be further clarified and described in more detail, with reference to the appended drawings showing different embodiments of a... according to the present invention.

Figure 1 is a perspective view showing the boom launch trailer of one embodiment of the present invention, and a boom truck to which the boom carried by the boom launch trailer is to be connected,

Figure 2a is a side view of the boom launch trailer of Figure 1 , with the vertically adjustable support legs thereof in a raised position, such that the wheels of the boom launch trailer are on the ground,

Figure 2b is a side view of the boom launch trailer of Figure 1 , with the vertically adjustable support legs thereof in a lowered position, such that the wheels of the boom launch trailer are lifted from the ground,

Figure 3 is a top view showing the boom launch trailer of Figure 1 before and after the rotational adjustment arrangement has adjusted the rotational position of the trailer frame relative the vehicle to which it is connected,

Figure 4a is a section view of the trailer frame and the rotational adjustment arrangement of the boom launch trailer of Figure 1 , seen from underneath,

Figure 4b is a section view of the rotational adjustment arrangement of the boom launch trailer of Figure 1 , seen from underneath.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following detailed description, some embodiments of the present invention will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. Even though in the following description, numerous specific details are set forth to provide a more thorough understanding of the present invention, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well- known constructions or functions are not described in detail, so as not to obscure the present invention. Figure 1 is a perspective view showing the boom launch trailer 1 of one embodiment of the present invention, and a boom truck 7 to which the boom carried by the boom launch trailer 1 is to be connected. The boom launch trailer 1 comprises a trailer frame 10 made from two parallel and interconnected beams, and a vehicle connection arrangement 11 provided at a frontmost first end 12 thereof. The vehicle connection arrangement 11 is arranged to allow the boom launch trailer to be connected to a vehicle 9 such as a semi-truck. The boom launch trailer 1 further comprises, as a rearmost second end 14 thereof, a wheel axle 13, wherein this wheel axle 13 has a pair of wheels 15 connected thereto for supporting the rear portion of the boom launch trailer 1 when it is connected to a pulling vehicle 9.

The boom launch trailer 1 further comprises a boom support arrangement 20 that is connected to the trailer frame 10. The boom support arrangement 20 is arranged to support and secure an elongated load 8, such as the boom illustrated herein. The boom support arrangement 20 comprises means for longitudinal adjustment of the elongated load 8 along a length of the trailer frame 10, as well as a rear boom support 21 and a main boom support 22 located in front of the rear boom support 21. The means for longitudinal adjustment of the elongated load 8 is provided by means of the rear boom support 21 and the main boom support 22 both being slidably connected to the trailer frame 10 and at least one of them being actuated therealong by means of at least one boom support actuator (not illustrated). Thus, the elongated load 8 may be moved in a longitudinal direction by means of the rear boom support 21 and the main boom support 22 sliding along the trailer frame 10 by means of the at least one boom support actuator while the elongated load 8 is supported by the boom support arrangement 20.

The boom launch trailer 1 further comprises a rotational adjustment arrangement 30 arranged to adjust a rotational position of the trailer frame 10 relative the vehicle 9 to which it is connected, by means of rotation about a vertical axis that is aligned with a permanent or semi-permanent pivot joint 16 of the trailer frame 10. In the illustrated embodiment, the permanent or semipermanent pivot joint 16 is provided at the vehicle connection arrangement 16, and the rotational adjustment arrangement 30 is provided at the second end 14 of the trailer frame 10. The rotational adjustment arrangement 30 comprises a pair of vertically adjustable and laterally separated support legs 31 connected to each other by a connection member 32.

As is seen in more detail in Figures 3, 4a and 4b, the connection member 32 is slidably connected to the trailer frame 10 such that the lateral position of the pair of vertically adjustable support legs 31 relative the trailer frame 10 may be controlled. The connection member 32 is slidably connected to the trailer frame 10 along a circular arc having a radius that is equal to the distance between the connection member 32 and the permanent or semipermanent pivot joint 16 about which the trailer frame 10 is arranged to rotate. The circular arc along which the connection arrangement 32 of the rotational adjustment arrangement 30 is slidably connected to the trailer frame 10 is thus centered on the permanent or semi-permanent pivot joint 16 of the trailer frame 10.

The connection member 32 of the rotational adjustment arrangement 30 and the trailer frame 10 are connected to each other by means of a linear actuator 35, seen in Figure 4b, that is movable between two end states and an intermediate state between said two end states. Figure 3 illustrates one end state and the intermediate state. The first end state is such that the linear actuator 35 is extended to a degree that the rotational adjustment arrangement 30 is moved along the circular arc to a laterally offset first position on a first side of the trailer frame 10. The second end state is such that the linear actuator 35 is retracted to a degree that the rotational adjustment arrangement 30 is moved along the circular arc to a laterally offset second position on an second side of the trailer frame 10 that is opposite the first side. Finally, the intermediate state is achieved by having the linear actuator 35 be positioned such that the rotational adjustment arrangement 30 is centered relative the trailer frame 10. The connection arrangement 32 of the rotational adjustment arrangement 30 is slidably connected to the trailer frame 10 by means of a sliding contact bearing, i.e. two plain surfaces arranged for low friction contact with each other. This may for example be realized by means of providing a film of lubricant therebetween, or simply by having the two opposing surfaces be polished such that their coefficient of friction is lower than similar unpolished surfaces.

Figures 2a and 2b are side views of the boom launch trailer 1 of Figure 1 . Figure 2a illustrates the vertically adjustable support legs 31 in a raised position, such that the wheels 15 of the boom launch trailer 1 are on the ground, while Figure 2b illustrates the vertically adjustable support legs 31 in a lowered position, such that the wheels 15 of the boom launch trailer 1 are lifted from the ground. As is seen in these figures, each one of the pair of vertically adjustable support legs 31 comprises a linear actuator 33 having a foot member 34 arranged at the movable end thereof, such that the foot member 34 may be lowered and raised relative the trailer frame 10 by means of the linear actuator 33. The foot member 34 is, in the raised position illustrated in Figure 2a, arranged higher than the lowest part of the pair of wheels 15 of the boom launch trailer 1 . The foot member 34 is, in the lowered position illustrated in Figure 2b, arranged lower than the lowest part of the part of wheels 15 of the boom launch trailer 1. This results in that the second end 14 of the trailer frame 10 is lifted relative the ground and the boom launch trailer 1 is caused to pivot about its vehicle connection arrangement 11 when connected to a vehicle 9 (not illustrated in Figures 2a and 2b) and the foot member 34 is lowered.

In the illustrated embodiment, the permanent or semi-permanent pivot joint 16 and the rotational adjustment arrangement 30 are provided on either side of a center of gravity of the boom launch trailer 10, when measured in a longitudinal direction of the boom launch trailer 1 along a horizontal plane. In other words, the permanent or semi-permanent pivot joint 16 is provided in front of the center of gravity of the boom launch trailer 1 , and the rotational adjustment arrangement 30 is provided rearwards of the center of gravity of the boom launch trailer 1 . The boom support arrangement 20 is arranged between the rotational adjustment arrangement 30 and the permanent or semi-permanent pivot joint 16 of the trailer frame 10, measured in a longitudinal direction of the boom launch trailer 1.

The person skilled in the art realizes that the present invention by no means is limited to the embodiments described above. The features of the described embodiments may be combined in different ways, and many modifications and variations are possible within the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting to the claim. The word "comprising" does not exclude the presence of other elements or steps than those listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.