A crane with improved guidance of flexible hose from the pillar to the first arm of the crane and a forestry vehicle comprising said crane

Abstract

The invention relates to a crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) and a forestry vehicle comprising said crane. The pillar (3) of the crane is rotatably mounted on the base frame (2) and the first arm (4) is movably mounted on the pillar via the joint (8). At least one flexible hose (12) connects a connection point (13) on the pillar (3) or the base frame (2) to the end of the first arm (4), where the at least one flexible hose (12) exits. Due to the movable mounting of the arm (4) the distance between the connection point (13) and the exit from the first arm (4) changes, which leads to coiling of the flexible hose (12) inside the arm (4). To prevent this, the first arm (4) is further provided with: - an opening (20) on the back part (43) of the first arm (4) immediately adjacent to the first joint (8) to allow entering of the at least one flexible hose (12) into the interior of the arm (4), - a movably mounted clamp (23) installed in the bottom part (42) of the arm (4) and arranged to compress at least one flexible hose (12) against the bottom part (42) of the arm (4), where a sliding surface (24) is provided to prevent slipping of the flexible hose (12), - two supporting rollers (21, 22), wherein at each side of the said opening (20) one supporting roller (21, 22) is installed, which allows the at least one flexible hose (12) to roll or at least touch the roller (21, 22), and - at least one sliding surface (16, 17) from a thin material joined or glued on the inner surface of the upper part (41) of the arm (4), which allows sliding of the at least one flexible hose (12).

Description

Field of the invention

[0001] The invention belongs to the field of cranes and crane arms, more specifically to a solution for crane arms with improved guidance of flexible hoses inside the arm. The present invention relates to a crane with improved guidance of a flexible hose from the pillar to the first arm of the crane and to a forestry vehicle comprising said crane.Background of the invention and the technical problem

[0002] A crane is a type of machine used for lifting and lowering materials and for moving them horizontally. It can be a stand-alone machine or it can be mounted on a forestry truck or forestry trailer, where it is used for loading and unloading trees or logs. Cranes on trucks or trailers usually have a pillar that is rotatably mounted on a frame, and a movable crane arm connected to the pillar. The prior art comprises different solutions for leading at least one flexible hose in the transition area from the crane column to the first crane arm, but in all solutions the flexible hose can be damaged during crane operation.

[0003] The technical problem, which is solved by the present invention, is design of a crane with improved guiding or installation of the at least one flexible hose from the pillar to the crane arm, so as to prevent the flexible hose from being damaged or to prolong the life span of the flexible hose.Prior art

[0004] Patent EP2947037 addresses the technical problem described above, but is designed in a different way. This solution discloses a crane with a crane pillar rotatably mounted about a vertical axis on a base frame and a first crane arm rotatably mounted on the crane pillar via a first joint. At least one hose leads from a first connection point of a flexible tube on the crane pillar or base frame to a second connection point in or on the first crane arm, wherein the rotational movement of the crane arm relative to the crane pillar results in an increase or decrease in the distance between the first and second connection points, with excess sections of flexible tube appearing when the distance between the first and second connection points decreases. The flexible hose is therefore arranged within the first crane arm according to this solution and enters the first arm through an opening on the bottom surface of the arm near the first joint, but it still does not completely solve the technical problem. Such excess sections are problematic due to damage to the hose, which is visible from the drawings in the document, which in some cases also leads to oil leaks, where the entire pipe needs to be replaced, and at the same time it is difficult to access the second connection point within the first arm of the crane.Description of the solution to the technical problem

[0005] The present invention addresses the problem of guiding flexible hoses inside a crane or from its pillar to the first arm, while also addressing the disadvantages of existing solutions. The technical problem is solved as defined in the independent claim, wherein possible embodiments of the solution are defined in the dependent claims.

[0006] The crane according to the invention comprises a pillar installed on the base frame so that the pillar is rotatable around a vertical axis, wherein a first crane arm is movably installed on the pillar with a joint, which can also be called a hinge or a fulcrum. The first arm is movable with a hydraulic cylinder, the operation of which is ensured by at least one flexible hose allowing oil flow. The at least one flexible hose connects the first connection point on the pillar or the base frame to the end of the first crane arm, wherein the at least one flexible hose(s) exit. The at least one flexible hose does not have a connection point inside the first arm, but on the contrary only runs through the arm and exits at the end of the arm. This has several advantages, including: easier installation of the hose, easier replacement of the hose during maintenance, and elimination of the possibility of oil leaks.

[0007] Due to the flexibility of the arm with regards to the pillar, the distance between the connection site and the exit point from the first crane arm will increase or decrease, which means that: in case the first crane arm is fully lifted, which represents a working position, the at least one flexible hose does not have any excess sections but runs smoothly without coils, bends or loops, in case the first crane arm is not fully lifted, but is lowering or in any intermediate positions or in the initial position, excess sections of the at least one flexible hose form, which consequently means the hose coils and thus forms several coils or loops present inside the crane arm possibly leading to damaged hose(s), in case the first crane arm is folded, the highest number of excess sections of the flexible hose is present, all located inside the crane arm, which also may lead to damaged hose(s).

[0008] The essence of the invention is that for preventing the above-described problems, the first crane arm, which comprises a bottom part, an upper part and a back part located adjacent to the joint, is further equipped with: with an opening for entering of the at least one flexible hose into the interior of the first arm, wherein said opening is provided on the back part of the first arm adjacent to the first joint, a movably mounted clamp arranged to compress at least one flexible hose against the bottom part of the arm, wherein said clamp is installed in the bottom part of the arm, where a sliding, preferably rubber, surface is attached, joined or glued to the inner surface of the bottom part of the arm, said siding surface preventing the flexible hose from slipping, two supporting rollers, wherein at each side of the said opening one supporting roller is installed, which allows the at least one flexible hose to roll or at least touch the roller, and at least one sliding surface from a thin material joined or glued on the inner surface of the upper part of the arm, which allows sliding of the at least one flexible hose.

[0009] In the preferred embodiment, the opening is approximately rectangularly shaped and with rounded corners, wherein the shorter side is along the longitudinal direction of the arm and the longer side is in the transverse direction of the arm. The opening has a rounded edge at least on the bottom outer side, which prevents damages to the hose, however, all edges of the opening may be rounded. Additionally or alternatively, the sheet metal from which the arm is made may be curved / bent in the area of the opening, wherein the angle of the bending may be between 100° and 140°.

[0010] Both supporting rollers are positioned near the arm wall and close to the edges of the opening, so that they can efficiently guide at least one flexible hose into the interior of the arm. The supporting rollers may be made from one or more pieces.

[0011] Said clamp comprises a base body having a bottom surface with several semicircular grooves, which ensure that the clamp optimally fits the hoses in the arm. Through the base body of the clamp two screws are installed, wherein the heads of the screws are installed on the outer side of the bottom part of the arm, so that the clamp can be moved upwards and downwards and thus compress the at least one hose without the need for interference in the interior of the arm. The claim is installed in the bottom part of the arm, downstream of the second supporting roller and the first hydraulic cylinder. The technical effect of using the adjustable clamp is that it is not necessary to screw the flexible hose inside the arm, and when replacing it, the claim is simply unscrewed at the connection point and pulled through the arm.

[0012] In the preferred embodiment, two sliding surfaces are provided and are located: a first sliding surface above the first supporting roller in the direction towards the upper part of the arm, and a second sliding surface in the upper part of the arm up to the space approximately above the clamp.

[0013] The sliding surfaces have a preferred thickness from 0.1 to 1.5 mm and due to their slim design do not take a lot of space, which means that there is more space for the flexible hoses. When the first arm is lowered, the excess sections of the flexible hose accumulating in the arm lean and glide along said sliding surfaces.

[0014] In comparison to the solution described in patent EP2947037, the different construction allows a larger radius of bending the hoses in the working area, which prevents the flexible hoses from getting damaged and elongates their life span. A consequence of the solution according to the invention is also a more optimal curve of the hose, which runs between the connection point and the clamp, which enables use of hoses with larger diameters. Therefore, a larger amount of oil can reach the users, which are arranged downstream of the arm, thus making the crane faster.

[0015] In addition to the opening allowing the at least one flexible hose to enter the first crane arm, the first crane arm can be further provided with at least one, preferably two additional openings, namely: a second opening located at the upper part of the arm, which is intended for visual control, and which is provided with a cover for closing the access to the arm interior, and / or a third opening located on the bottom side of the first arm, which is intended for visual control of the flexible hose, wherein this opening is located in the part between the pillar and the hydraulic cylinder arranged to move the first crane arm.

[0016] The crane according to the invention can be mounted on any suitable forestry vehicle, wherein the forestry vehicle is preferably a forestry trailer or a forestry truck.

[0017] The invention will be described in further detail based on exemplary embodiments and figures, which show: Figure 1A schematic view of the crane with the pillar, the hydraulic cylinder and two arms Figure 2The first crane arm according to a possible embodiment in a working position, i.e. in a completely lifted position Figure 3The first crane arm according to a possible embodiment in an intermediate position Figure 4The first crane arm according to a possible embodiment in a folded position, when the flexible hose has the highest number of coiled sections Figure 5A cross-section of a part of the crane arm according to a possible embodiment, wherein the openings on the back, bottom and upper parts of the arm are visible Figure 6The angle of bending the sheet metal in the area of the opening for guiding at least one flexible hose Detailed description of the invention and exemplary embodiments

[0018] Figure 1 is a schematic view of the crane 1 with the pillar 3, the hydraulic cylinder 10 and two arms 4, 4a, wherein the second arm 4a can be elongated with a single our double telescope 4b and 4c, and wherein the pillar 3 is arranged on the base frame 2 in a manner allowing rotation around the vertical axis. The first arm 4 of the crane 1 is movably mounted on said pillar 3 with a joint 8. The first arm 4 is movable with the hydraulic cylinder 10, which can operate due to at least one flexible hose 12 allowing oil flow from the metal pipe 15, which supplies the oil to the connection point 13 on the pillar 3 or on the base frame 2 of the crane 1. The at least one flexible hose 12 thus connects the first connection point 13 on the pillar or the base frame 2 until the end of the first arm 4, where the at least one flexible hose 12 or hoses exit. The at least one flexible hose 12 is not interrupted by a second connection point inside the first arm 4, but only runs through it and exits it at the end of the arm.

[0019] Figures 2 to 4 show different positions of the first arm 1 of the crane relative to the pillar 3 of the crane, in which several different distances between the connection site 13 and the exit from the first arm 4 of the crane occur, which means that: in case the first crane arm 4 is fully lifted (Figure 2), which represents a working position, the at least one flexible hose 12 does not have any excess sections but runs smoothly without coils, bends or loops, in case the first crane arm 4 is not fully lifted (figure 3), but is lowering or in any intermediate positions or in the initial position, excess sections of the at least one flexible hose 12 form, which slide along the supporting roller 21 and / or supporting roller 22 and can also touch or slide along the sliding surfaces 16, 17, which are present inside the first arm 4, in case the first crane arm 4 is folded, the excess section of the flexible hose 12 is the longest (Figure 4) and consequently forms a part of a circle and runs from the opening via the supporting rollers and sliding surfaces 16, 17 to the clamp.

[0020] For improved guidance of the at least one flexible hose 12, the first arm 4 of the crane 1, which comprises a bottom part 42, an upper part 41 and a back part 43 adjacent to the joint 8, is further provided with: with an opening 20 for entering of the at least one flexible hose 12 into the interior of the first arm 4, wherein said opening 20 is provided on the back part 43 of the first arm 4 immediately adjacent to the first joint 8, a movably mounted clamp 23 arranged to compress at least one flexible hose 12 against the bottom part 42 of the arm 4, wherein said clamp 23 is installed in the bottom part 42 of the arm 4, where a sliding, preferably rubber, surface 24 is attached, joined or glued to the inner surface of the bottom part 42 of the arm 4, said siding surface 24 preventing the flexible hose from slipping, two supporting rollers 21, 22, wherein at each side of the said opening 20 one supporting roller 21, 22 is installed, which allows the at least one flexible hose 12 to roll or at least touch the roller 21, 22, and at least one sliding surface 16, 17 from a thin material with thickness from 0.1 mm to 1.5 mm joined or glued on the inner surface of the upper part 41 of the arm 4, which allows sliding of the at least one flexible hose 12, wherein the sliding surfaces are located: ∘ the first sliding surface 16 above the first supporting roller 21 in the direction towards the upper part 42 of the arm 4, and ∘ a second sliding surface 17 along the upper part 41 of the arm 4 to the area located approximately above the clamp 23.

[0021] Thus the at least one flexible hose 12 is guided that in a fully extended position of the arm 4 (figure 2) the flexible 12 runs essentially straight from the supporting roller to the clamp 23. In the fully folded position of the arm 4 (figure 4) the at least one flexible hose 12 runs in the following manner; the hose enters through the opening 20 into the interior of the first 4 at an approximately right angle relative to the opening and touches both supporting rollers 21, 22. Then, the hose touches the upper interior surface of the arm and then lowers to the clamp 23, thus forming a big loop with a large radius of curvature, which prevents damage to the hoses, while also allowing use of hoses with larger diameters. In case of intermediate positions, the flexible hose forms a smaller loop as shown in figure 3.

[0022] Said clamp 23 (visible in figures 2 to 5) comprises a base body 23a having a bottom surface with a plurality of semicircular grooves, which ensure that the clamp optimally fits the hoses in the arm. Through the base body 23a of the clamp two screws 23b are installed, wherein the heads of the screws are installed on the outer side of the bottom part 42 of the arm 4, so that the clamp 23 can be moved upwards and downwards and thus compress the at least one hose 12 without the need for interference in the interior of the arm 4. The clamp is installed in the bottom part 42 of the arm 4, downstream of the second supporting roller 22 and the first hydraulic cylinder 10.

[0023] In addition to the opening 20 allowing the at least one flexible hose 12 to enter the first crane arm 4, the first crane arm 4 can be further provided with two additional openings 18, 19 (figure 5), namely: a second opening 18 located at the upper part 41 of the arm 4, which is intended for visual control, and which is provided with a cover for closing the access to the arm interior, and / or a third opening 19 located on the bottom side 42 of the first arm 4, which is intended for visual control of the flexible hose 12, wherein this opening 19 is located in the part between the pillar 3 and the hydraulic cylinder 10 arranged to move the first crane arm 4.

[0024] Figure 5 shows a part of the first arm 4, wherein the above-mentioned openings 18, 19, 20 are visible, while figure 6 shows the angle β of bending the sheet metal in the area of the opening 20, which can be between 100° and 140°.

Examples

Embodiment Construction

[0018]Figure 1 is a schematic view of the crane 1 with the pillar 3, the hydraulic cylinder 10 and two arms 4, 4a, wherein the second arm 4a can be elongated with a single our double telescope 4b and 4c, and wherein the pillar 3 is arranged on the base frame 2 in a manner allowing rotation around the vertical axis. The first arm 4 of the crane 1 is movably mounted on said pillar 3 with a joint 8. The first arm 4 is movable with the hydraulic cylinder 10, which can operate due to at least one flexible hose 12 allowing oil flow from the metal pipe 15, which supplies the oil to the connection point 13 on the pillar 3 or on the base frame 2 of the crane 1. The at least one flexible hose 12 thus connects the first connection point 13 on the pillar or the base frame 2 until the end of the first arm 4, where the at least one flexible hose 12 or hoses exit. The at least one flexible hose 12 is not interrupted by a second connection point inside the first arm 4, but only runs through it and ...

Field of the invention

[0001] The invention belongs to the field of cranes and crane arms, more specifically to a solution for crane arms with improved guidance of flexible hoses inside the arm. The present invention relates to a crane with improved guidance of a flexible hose from the pillar to the first arm of the crane and to a forestry vehicle comprising said crane.Background of the invention and the technical problem

[0002] A crane is a type of machine used for lifting and lowering materials and for moving them horizontally. It can be a stand-alone machine or it can be mounted on a forestry truck or forestry trailer, where it is used for loading and unloading trees or logs. Cranes on trucks or trailers usually have a pillar that is rotatably mounted on a frame, and a movable crane arm connected to the pillar. The prior art comprises different solutions for leading at least one flexible hose in the transition area from the crane column to the first crane arm, but in all solutions the flexible hose can be damaged during crane operation.

[0003] The technical problem, which is solved by the present invention, is design of a crane with improved guiding or installation of the at least one flexible hose from the pillar to the crane arm, so as to prevent the flexible hose from being damaged or to prolong the life span of the flexible hose.Prior art

[0004] Patent EP2947037 addresses the technical problem described above, but is designed in a different way. This solution discloses a crane with a crane pillar rotatably mounted about a vertical axis on a base frame and a first crane arm rotatably mounted on the crane pillar via a first joint. At least one hose leads from a first connection point of a flexible tube on the crane pillar or base frame to a second connection point in or on the first crane arm, wherein the rotational movement of the crane arm relative to the crane pillar results in an increase or decrease in the distance between the first and second connection points, with excess sections of flexible tube appearing when the distance between the first and second connection points decreases. The flexible hose is therefore arranged within the first crane arm according to this solution and enters the first arm through an opening on the bottom surface of the arm near the first joint, but it still does not completely solve the technical problem. Such excess sections are problematic due to damage to the hose, which is visible from the drawings in the document, which in some cases also leads to oil leaks, where the entire pipe needs to be replaced, and at the same time it is difficult to access the second connection point within the first arm of the crane.Description of the solution to the technical problem

[0005] The present invention addresses the problem of guiding flexible hoses inside a crane or from its pillar to the first arm, while also addressing the disadvantages of existing solutions. The technical problem is solved as defined in the independent claim, wherein possible embodiments of the solution are defined in the dependent claims.

[0006] The crane according to the invention comprises a pillar installed on the base frame so that the pillar is rotatable around a vertical axis, wherein a first crane arm is movably installed on the pillar with a joint, which can also be called a hinge or a fulcrum. The first arm is movable with a hydraulic cylinder, the operation of which is ensured by at least one flexible hose allowing oil flow. The at least one flexible hose connects the first connection point on the pillar or the base frame to the end of the first crane arm, wherein the at least one flexible hose(s) exit. The at least one flexible hose does not have a connection point inside the first arm, but on the contrary only runs through the arm and exits at the end of the arm. This has several advantages, including: easier installation of the hose, easier replacement of the hose during maintenance, and elimination of the possibility of oil leaks.

[0007] Due to the flexibility of the arm with regards to the pillar, the distance between the connection site and the exit point from the first crane arm will increase or decrease, which means that: in case the first crane arm is fully lifted, which represents a working position, the at least one flexible hose does not have any excess sections but runs smoothly without coils, bends or loops, in case the first crane arm is not fully lifted, but is lowering or in any intermediate positions or in the initial position, excess sections of the at least one flexible hose form, which consequently means the hose coils and thus forms several coils or loops present inside the crane arm possibly leading to damaged hose(s), in case the first crane arm is folded, the highest number of excess sections of the flexible hose is present, all located inside the crane arm, which also may lead to damaged hose(s).

[0008] The essence of the invention is that for preventing the above-described problems, the first crane arm, which comprises a bottom part, an upper part and a back part located adjacent to the joint, is further equipped with: with an opening for entering of the at least one flexible hose into the interior of the first arm, wherein said opening is provided on the back part of the first arm adjacent to the first joint, a movably mounted clamp arranged to compress at least one flexible hose against the bottom part of the arm, wherein said clamp is installed in the bottom part of the arm, where a sliding, preferably rubber, surface is attached, joined or glued to the inner surface of the bottom part of the arm, said siding surface preventing the flexible hose from slipping, two supporting rollers, wherein at each side of the said opening one supporting roller is installed, which allows the at least one flexible hose to roll or at least touch the roller, and at least one sliding surface from a thin material joined or glued on the inner surface of the upper part of the arm, which allows sliding of the at least one flexible hose.

[0009] In the preferred embodiment, the opening is approximately rectangularly shaped and with rounded corners, wherein the shorter side is along the longitudinal direction of the arm and the longer side is in the transverse direction of the arm. The opening has a rounded edge at least on the bottom outer side, which prevents damages to the hose, however, all edges of the opening may be rounded. Additionally or alternatively, the sheet metal from which the arm is made may be curved / bent in the area of the opening, wherein the angle of the bending may be between 100° and 140°.

[0010] Both supporting rollers are positioned near the arm wall and close to the edges of the opening, so that they can efficiently guide at least one flexible hose into the interior of the arm. The supporting rollers may be made from one or more pieces.

[0011] Said clamp comprises a base body having a bottom surface with several semicircular grooves, which ensure that the clamp optimally fits the hoses in the arm. Through the base body of the clamp two screws are installed, wherein the heads of the screws are installed on the outer side of the bottom part of the arm, so that the clamp can be moved upwards and downwards and thus compress the at least one hose without the need for interference in the interior of the arm. The claim is installed in the bottom part of the arm, downstream of the second supporting roller and the first hydraulic cylinder. The technical effect of using the adjustable clamp is that it is not necessary to screw the flexible hose inside the arm, and when replacing it, the claim is simply unscrewed at the connection point and pulled through the arm.

[0012] In the preferred embodiment, two sliding surfaces are provided and are located: a first sliding surface above the first supporting roller in the direction towards the upper part of the arm, and a second sliding surface in the upper part of the arm up to the space approximately above the clamp.

[0013] The sliding surfaces have a preferred thickness from 0.1 to 1.5 mm and due to their slim design do not take a lot of space, which means that there is more space for the flexible hoses. When the first arm is lowered, the excess sections of the flexible hose accumulating in the arm lean and glide along said sliding surfaces.

[0014] In comparison to the solution described in patent EP2947037, the different construction allows a larger radius of bending the hoses in the working area, which prevents the flexible hoses from getting damaged and elongates their life span. A consequence of the solution according to the invention is also a more optimal curve of the hose, which runs between the connection point and the clamp, which enables use of hoses with larger diameters. Therefore, a larger amount of oil can reach the users, which are arranged downstream of the arm, thus making the crane faster.

[0015] In addition to the opening allowing the at least one flexible hose to enter the first crane arm, the first crane arm can be further provided with at least one, preferably two additional openings, namely: a second opening located at the upper part of the arm, which is intended for visual control, and which is provided with a cover for closing the access to the arm interior, and / or a third opening located on the bottom side of the first arm, which is intended for visual control of the flexible hose, wherein this opening is located in the part between the pillar and the hydraulic cylinder arranged to move the first crane arm.

[0016] The crane according to the invention can be mounted on any suitable forestry vehicle, wherein the forestry vehicle is preferably a forestry trailer or a forestry truck.

[0017] The invention will be described in further detail based on exemplary embodiments and figures, which show: Figure 1A schematic view of the crane with the pillar, the hydraulic cylinder and two arms Figure 2The first crane arm according to a possible embodiment in a working position, i.e. in a completely lifted position Figure 3The first crane arm according to a possible embodiment in an intermediate position Figure 4The first crane arm according to a possible embodiment in a folded position, when the flexible hose has the highest number of coiled sections Figure 5A cross-section of a part of the crane arm according to a possible embodiment, wherein the openings on the back, bottom and upper parts of the arm are visible Figure 6The angle of bending the sheet metal in the area of the opening for guiding at least one flexible hose Detailed description of the invention and exemplary embodiments

[0018] Figure 1 is a schematic view of the crane 1 with the pillar 3, the hydraulic cylinder 10 and two arms 4, 4a, wherein the second arm 4a can be elongated with a single our double telescope 4b and 4c, and wherein the pillar 3 is arranged on the base frame 2 in a manner allowing rotation around the vertical axis. The first arm 4 of the crane 1 is movably mounted on said pillar 3 with a joint 8. The first arm 4 is movable with the hydraulic cylinder 10, which can operate due to at least one flexible hose 12 allowing oil flow from the metal pipe 15, which supplies the oil to the connection point 13 on the pillar 3 or on the base frame 2 of the crane 1. The at least one flexible hose 12 thus connects the first connection point 13 on the pillar or the base frame 2 until the end of the first arm 4, where the at least one flexible hose 12 or hoses exit. The at least one flexible hose 12 is not interrupted by a second connection point inside the first arm 4, but only runs through it and exits it at the end of the arm.

[0019] Figures 2 to 4 show different positions of the first arm 1 of the crane relative to the pillar 3 of the crane, in which several different distances between the connection site 13 and the exit from the first arm 4 of the crane occur, which means that: in case the first crane arm 4 is fully lifted (Figure 2), which represents a working position, the at least one flexible hose 12 does not have any excess sections but runs smoothly without coils, bends or loops, in case the first crane arm 4 is not fully lifted (figure 3), but is lowering or in any intermediate positions or in the initial position, excess sections of the at least one flexible hose 12 form, which slide along the supporting roller 21 and / or supporting roller 22 and can also touch or slide along the sliding surfaces 16, 17, which are present inside the first arm 4, in case the first crane arm 4 is folded, the excess section of the flexible hose 12 is the longest (Figure 4) and consequently forms a part of a circle and runs from the opening via the supporting rollers and sliding surfaces 16, 17 to the clamp.

[0020] For improved guidance of the at least one flexible hose 12, the first arm 4 of the crane 1, which comprises a bottom part 42, an upper part 41 and a back part 43 adjacent to the joint 8, is further provided with: with an opening 20 for entering of the at least one flexible hose 12 into the interior of the first arm 4, wherein said opening 20 is provided on the back part 43 of the first arm 4 immediately adjacent to the first joint 8, a movably mounted clamp 23 arranged to compress at least one flexible hose 12 against the bottom part 42 of the arm 4, wherein said clamp 23 is installed in the bottom part 42 of the arm 4, where a sliding, preferably rubber, surface 24 is attached, joined or glued to the inner surface of the bottom part 42 of the arm 4, said siding surface 24 preventing the flexible hose from slipping, two supporting rollers 21, 22, wherein at each side of the said opening 20 one supporting roller 21, 22 is installed, which allows the at least one flexible hose 12 to roll or at least touch the roller 21, 22, and at least one sliding surface 16, 17 from a thin material with thickness from 0.1 mm to 1.5 mm joined or glued on the inner surface of the upper part 41 of the arm 4, which allows sliding of the at least one flexible hose 12, wherein the sliding surfaces are located: ∘ the first sliding surface 16 above the first supporting roller 21 in the direction towards the upper part 42 of the arm 4, and ∘ a second sliding surface 17 along the upper part 41 of the arm 4 to the area located approximately above the clamp 23.

[0021] Thus the at least one flexible hose 12 is guided that in a fully extended position of the arm 4 (figure 2) the flexible 12 runs essentially straight from the supporting roller to the clamp 23. In the fully folded position of the arm 4 (figure 4) the at least one flexible hose 12 runs in the following manner; the hose enters through the opening 20 into the interior of the first 4 at an approximately right angle relative to the opening and touches both supporting rollers 21, 22. Then, the hose touches the upper interior surface of the arm and then lowers to the clamp 23, thus forming a big loop with a large radius of curvature, which prevents damage to the hoses, while also allowing use of hoses with larger diameters. In case of intermediate positions, the flexible hose forms a smaller loop as shown in figure 3.

[0022] Said clamp 23 (visible in figures 2 to 5) comprises a base body 23a having a bottom surface with a plurality of semicircular grooves, which ensure that the clamp optimally fits the hoses in the arm. Through the base body 23a of the clamp two screws 23b are installed, wherein the heads of the screws are installed on the outer side of the bottom part 42 of the arm 4, so that the clamp 23 can be moved upwards and downwards and thus compress the at least one hose 12 without the need for interference in the interior of the arm 4. The clamp is installed in the bottom part 42 of the arm 4, downstream of the second supporting roller 22 and the first hydraulic cylinder 10.

[0023] In addition to the opening 20 allowing the at least one flexible hose 12 to enter the first crane arm 4, the first crane arm 4 can be further provided with two additional openings 18, 19 (figure 5), namely: a second opening 18 located at the upper part 41 of the arm 4, which is intended for visual control, and which is provided with a cover for closing the access to the arm interior, and / or a third opening 19 located on the bottom side 42 of the first arm 4, which is intended for visual control of the flexible hose 12, wherein this opening 19 is located in the part between the pillar 3 and the hydraulic cylinder 10 arranged to move the first crane arm 4.

[0024] Figure 5 shows a part of the first arm 4, wherein the above-mentioned openings 18, 19, 20 are visible, while figure 6 shows the angle β of bending the sheet metal in the area of the opening 20, which can be between 100° and 140°.

Examples

Embodiment Construction

[0018]Figure 1 is a schematic view of the crane 1 with the pillar 3, the hydraulic cylinder 10 and two arms 4, 4a, wherein the second arm 4a can be elongated with a single our double telescope 4b and 4c, and wherein the pillar 3 is arranged on the base frame 2 in a manner allowing rotation around the vertical axis. The first arm 4 of the crane 1 is movably mounted on said pillar 3 with a joint 8. The first arm 4 is movable with the hydraulic cylinder 10, which can operate due to at least one flexible hose 12 allowing oil flow from the metal pipe 15, which supplies the oil to the connection point 13 on the pillar 3 or on the base frame 2 of the crane 1. The at least one flexible hose 12 thus connects the first connection point 13 on the pillar or the base frame 2 until the end of the first arm 4, where the at least one flexible hose 12 or hoses exit. The at least one flexible hose 12 is not interrupted by a second connection point inside the first arm 4, but only runs through it and ...

Claims

1. A crane (1) with improved guidance of flexible hose (12) from a pillar (3) to a first arm (4) of the crane (1), wherein said crane (1) comprises: - the pillar (3) installed on a base frame (2) in a manner allowing rotation around a vertical axis, - the first arm (4) of the crane, which is movably mounted on the pillar (3) through a joint (8), - a hydraulic cylinder (10) for moving the first arm (4) of the crane, - at least one flexible hose (12), which enables operation of the hydraulic cylinder (10), wherein the at least one flexible hose (12) connects a first connection point (13) on the pillar (3) or the base frame (2) to the end of the first arm (4), where at least one flexible hose (12) exits, characterized in that the first arm (4) comprises a bottom part (42), and upper part (41) and a back part (43), which is located adjacent to the joint (8), and the first arm (4) further comprises: - an opening (20) for entering of the at least one flexible hose (12) into the interior of the first arm (4), wherein said opening (20) is provided on the back part (43) of the first arm (4) immediately adjacent to the first joint (8), - a movably mounted clamp (23) arranged to compress at least one flexible hose (12) against the bottom part (42) of the arm (4), wherein said clamp (23) is installed in the bottom part (42) of the arm (4), where a sliding surface (24) is attached, joined or glued to the inner surface of the bottom part 42 of the arm 4, said siding surface (24) preventing the flexible hose (12) from slipping, - two supporting rollers (21, 22), wherein at each side of the said opening (20) one supporting roller (21, 22) is installed, which allows the at least one flexible hose (12) to roll or at least touch the roller (21, 22), and - at least one sliding surface (16, 17) from a thin material joined or glued on the inner surface of the upper part (41) of the arm (4), which allows sliding of the at least one flexible hose (12).

2. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to claim 1, wherein the opening (20) for entering the at least one flexible hose (12) into the interior of the first arm (4) is approximately rectangular with rounded corners, wherein the shorter side of the opening (20) is in the longitudinal direction of the arm (4) and the longer side of the opening is in the transverse direction of the arm (4).

3. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to claim 2, wherein the opening (20) has at least on its bottom side a rounded edge, which prevents damages to the at least one flexible hose (12), wherein all edges of the opening (20) can be rounded.

4. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein in the area of the opening (20) the sheet metal, from which the arm (4) is made, is bent and the angle of bending is between 100° and 140°.

5. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein said clamp (23) comprises a base body (23a), having a bottom surface with a plurality of semicircular grooves, which ensure that the clamp optimally fits the at least one flexible hose (12) in the arm (4), wherein through the base body (23a) of the clamp two screws (23b) are installed, wherein the heads of the screws are installed on the outer side of the bottom part (42) of the arm (4), so that the clamp (23) can be moved upwards and downwards and thus compress the at least one flexible hose (12) without the need for interference in the interior of the arm.

6. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to the preceding claim, wherein the clamp (23) is arranged in the bottom part (42) of the arm (4), downstream of the second supporting roller (22) and the first hydraulic cylinder (10).

7. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein two sliding surfaces (16, 17) are provided in the following locations: - a first sliding surface (16) above the first supporting roller (21) in the direction towards the upper part (41) of the arm, and - a second sliding surface (17) in the upper part (41) of the arm up to the space approximately above the clamp (23).

8. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein the sliding surfaces (16, 17) have a thickness from 0.1 mm to 1.5 mm.

9. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein the first arm (4) of the crane is in addition to the opening (20) for entering of at least one flexible hose (12) into the interior of the arm provided with at least one, preferably two additional openings (18, 19), namely: - a second opening (18) located at the upper part (41) of the arm (4), which is intended for visual control, and which is provided with a cover for closing the access to the arm interior, and / or - a third opening (19) located on the bottom side (42) of the first arm (4), which is intended for visual control of the flexible hose (12), wherein this opening (19) is located in the part between the pillar (3) and the hydraulic cylinder (10) arranged to move the first arm (4) of the crane (1).

10. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein the first arm (4) of the crane (1) can be in different positions and - in case the first crane arm (4) is fully lifted, the at least one flexible hose (12) does not have any excess sections but runs smoothly without coils, bends or loops, to the clamp (23), - in case the first crane arm 4 is not fully lifted, but is lowering or in any intermediate positions or in the initial position, excess sections of the at least one flexible hose (12) form, which slide along the first supporting roller (21) and / or the second supporting roller (22) and can also touch or slide along the sliding surfaces (16, 17), which are present inside the first arm (4), - in case the first crane arm (4) is folded, the excess section of the flexible hose (12) is the longest and consequently forms a part of a circle and runs from the opening (20) via the supporting rollers (21, 22) and sliding surfaces (16, 17) to the clamp (23).

11. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein a second arm (4a) is connected to the first arm (4).

12. The crane (1) with improved guidance of flexible hose (12) from the pillar (3) to the first arm (4) of the crane (1) according to any of the preceding claims, wherein the second arm (4a) is provided with at least one telescopic arm (4b, 4c).

13. A forestry vehicle comprising the crane according to any of the preceding claims.

14. The forestry vehicle according to the preceding claim, wherein the forestry vehicle is a forestry trailer or a forestry truck.

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