FI68208B - LYFTKRAN - Google Patents

Description

68208

Crane

Modern vehicle-mounted cranes can generally be folded from the operating position to the compact position during transport, for which purpose the crane is equipped with a so-called crane. with a column folding joint.

Structurally different articulation solutions have been implemented in cranes from different manufacturers. They use a hydraulic cylinder or special mechanical design solutions as the locking member. What these solutions have in common has been the relatively high weight of the column and, when using the cylinder, also the high cost. Mechanical joint locking solutions have resulted in asymmetric joint forces and, on the road to avoid stress-strain growth, in heavy column construction. 15 In addition, the locking of an asymmetrical joint has caused deformation of the column during use and, as a result, high edge pressures on the joints, which quickly wear the joints loose and increase maintenance costs and reduce the crane's operating and replacement value. 20 Four-point support has also been sought in a pivot joint, e.g. in DE-A-25 58 613. However, the structure does not meet the operating requirements of a modern crane, as the locking shaft must be completely removed from the hole by hand and moved to another hole. In this case, the hole in the shaft 25 must be looser than normal in order for the shaft to be put in place and the looseness of the locking felt uncomfortable for the crane operator whose seat is attached to the column.

U.S. Patent No. 3,819,059 discloses a locking structure of approximately the same type which has resulted in an unfavorable solution in terms of transmission. The locking is also quite complicated and not quite reliable.

The aim is to provide a new crane in which the above-mentioned drawbacks have been eliminated.

The invention therefore relates to a crane comprising a base, a two-part, articulated wheel mounted here, a lifting boom articulated to the top of the column, a lifting cylinder articulated at one end to the lifting boom and at the other end to the lower part of the column 5, and a lifting cylinder in the operating and transport position of the crane.

The crane according to the invention is mainly characterized in that the locking means comprise two pivoting levers 10 connected to each other via the pivot axis of the lifting cylinder, each provided with a shoulder towards the top of the column, The mutual contact surfaces of the shoulders are preferably formed as self-retaining wedge surfaces.

The folding joint of the crane according to the invention has a four-surface support in both the operating and transport positions, thanks to which the joint is resistant to external stresses when the joint loads are symmetrical and the stresses are reduced compared to known solutions. The outer dimensions of the joint 20 are made smaller and the column as a whole lighter, whereby in addition to material savings, cheaper production and easier use are also achieved.

The invention will be explained in more detail below with reference to the accompanying drawing.

Figure 1 shows a jib crane seen from the right side in the operating position of the crane.

Figure 2 shows the preliminary step of folding the crane to the final transport position.

Figure 3 shows the crane in the final transport position.

Figure 4 shows on a larger scale the column joint from the right side, i.e. seen from the drive side and locked in the drive position.

Figure 5 shows the same joint from the left side.

Fig. 6 shows the column hinge locked in the transport position.

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Figure 7 shows the same from the other side.

Fig. 8 shows a section at the lever axis in the longitudinal direction of the lever with the joint locked in the operating position.

5 An exemplary crane according to the drawing comprises a platform 1, a lifting boom 2, a transfer boom 3, this extension 4, a grapple 5, a lifting cylinder 6, a transfer cylinder 7 and a two-part column with an upper part 8 and a lower part 9. the invention relates, is generally indicated by reference numeral 1a.

When folding the crane from the operating position according to Fig. 1 to the transport position according to Fig. 3, where dimension B represents the permissible transport width and dimension H the permitted transport height, the position according to Fig. 2 is a preliminary step. The lifting moment of the lifting cylinder 6 must overcome the boom 2, 3, 4 with respect to joint 11. When the crane is in this position, the joint 10 is opened from the locking of the operating position, after which the lifting cylinder 6 tilts the top 8 of the column around the joint 13 to the transport position, where the joint 10 is locked again. During movement, the weight of the boom rests on the tilt support 12 and the column top joint 11.

The structure 25 and operation of the folding joint 10 will now be described with reference to Figs.

The lifting cylinder 6 pivots relative to the lower part 9 of the column on a joint 14 and a hollow shaft 15, Fig. 8. Inside the hollow shaft 15 there is a groove shaft 16 connected at one end to a locking lever 30 18 with a handle 17 and at the other end to a locking lever 20. 20 thus move fixedly together. The levers 18 and 20 are provided with shoulders 21 and 22, respectively, which, when the crane is in the position according to Figures 1, 2, 4, 5 and 8, rest on the abutment shoulders 23, 24 formed in the top 8 of the column 8 and in the position according to Figures 3, 6 and 7. abutment shoulders 25 and 26 formed at the top of the column.

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The mutual contact surfaces of the shoulders are preferably formed as self-retaining wedge surfaces which firmly bind the joint together. Continuous backlash-free locking can be achieved, for example, by means of springs 27 and 28.

5 Compared to the known joint solutions, this also has the advantage that the joint wear reduces the joint clearances, on the contrary, the wear in the known joints increases the clearances and causes additional maintenance costs. When the crane is in the operating position, the locking can still be ensured, for example, by opening stops 30 mounted on the guides 29.

The abutment shoulders 25 and 26 of the transport position are preferably dimensioned so that the shoulders 21 and 22 of the pivot levers 18 and 20 hit them as the top 8 of the column is tilted to the transport position, i.e. the abutment shoulders 25 and 26 also act as tilt limiters.

Claims (3)

68208 5 A crane comprising a base (1), a two-part articulated column (8, 9) mounted thereon, a lifting boom (2) articulated to the upper part (8) of the column 5, a lifting cylinder (6) articulated at one end to the lifting boom (2) and at one end to the lower part (9) of the column, and means for locking the lifting cylinder (6) relative to the upper part (8) of the column in the crane operating position and transport position, characterized in that the locking means comprise two lifting cylinders (6) via a pivot shaft (15) a connected pivot lever (18, 20), each provided with a shoulder (21, 22) facing the top (8) of the column, and counter-bearings (23, 25, 24, 26) for the operating position and the transport position, respectively, formed in the upper part (8) of the column. ). Crane according to Claim 1, characterized in that the mutual contact surfaces of the shoulders (21, 22) of the pivot levers (18, 20) and the abutment shoulders (23, 25, 24, 26) 20 of the column (8) are formed as self-retaining wedge surfaces. Crane according to Claim 1 or 2, characterized in that the swivel levers (18, 20) are provided with retaining springs in order to ensure that the locking is continuously free of play.