Crane

Abstract

The present invention relates to a crane having a multiple-piece longitudinal structural part, in particular a tower or boom, whose pieces comprise corner arms or horizontal beams which can be placed next to one another and which can be releasably connected to one another by a mortise and tenon joint, wherein the mortise and tenon joint comprises a tongue which can be plugged into a tongue receiver and which can be fixed by means of at least one crossbar which can be inserted transversely to the plug-in direction of the tongue. In accordance with the invention, the crossbar of the mortise and tenon joint can be spread apart by a spreading device such that the pieces of the longitudinal structural part to be connected can be clamped to one another by spreading apart the crossbar.

Claims

1. A crane having a multiple-piece longitudinal structural part that is either a tower or a boom, where pieces of the tower or boom comprise corner arms or horizontal beams which can be placed next to one another and which can be releasably connected to one another by a mortise and tenon joint, wherein the mortise and tenon joint comprises a tongue which can be plugged into a tongue receiver and which can be fixed in the tongue receiver by means of at least one crossbar insertable transversely to a plug-in direction of the tongue, wherein the crossbar can be spread apart by a spreading device such that the pieces of the longitudinal structural part to be connected can be clamped to one another by spreading apart the crossbar, wherein the crossbar comprises at least two spreading parts which are displaceable relative to one another in a longitudinal crossbar direction and which comprise at least one oblique surface which converts a relative movement of the spreading parts in the longitudinal crossbar direction into a spreading movement transversely to the longitudinal crossbar direction, and wherein the two spreading parts form crossbar half-shells which are seated on one another, the crossbar half-shells aligned in opposite directions to one another, where each of the crossbar half-shells has a cross-section that includes a rounded portion and a substantially planar portion, the cross-sections being an approximately crescent-shaped or semi-oval-shaped cross-section, wherein the crossbar has a cross-section differing from a circular shape, and wherein the crossbar has a cross-section that is approximately an oval cross-section.

2. The crane in accordance with claim 1, wherein the crossbar can be spread apart in a longitudinal direction of the tongue or of the longitudinal structural part in an inserted state such that the tongue can be clamped into the tongue receiver and the pieces of the longitudinal structure part can be clamped to one another in the longitudinal direction of the longitudinal structure part.

3. The crane in accordance with claim 1, wherein the oblique surface forms a slanted longitudinal sectional plane through the crossbar.

4. The crane in accordance with claim 1, wherein at least one of the spreading parts forms a spreading wedge, and wherein the crossbar half-shells are spread apart from one another via the spreading movement transversely to the longitudinal crossbar direction.

5. The crane in accordance with claim 1, wherein the two spreading parts forming the crossbar half-shells are of approximately the same size.

6. The crane in accordance with claim 1, wherein the crossbar comprises three or more spreading parts which are displaceable in the longitudinal crossbar direction relative to one another and have oblique surfaces aligned transversely with respect to a common spreading plane.

7. The crane in accordance with claim 1, further comprising a middle wedge having two oppositely disposed oblique surfaces arranged between two outer wedges which are both oriented in opposite directions to the middle wedge or which bound a V-shaped intermediate space between them in which the middle wedge is seated.

8. The crane in accordance with claim 1, wherein the at least one oblique surface is aligned substantially perpendicular to a plane which is defined by a longitudinal crossbar axis and by a longitudinal tongue or structural part axis.

9. The crane in accordance with claim 1, wherein the crossbar has a main cross-sectional axis which extends approximately in parallel with a longitudinal axis of the tongue or the longitudinal structural part.

10. The crane in accordance with claim 1, wherein the tongue or one of the corner arms or one of the horizontal beams having the tongue receiver has/have a plug-through cut-out for the crossbar which is adapted to the spreadable crossbar and which is of an elongated hole shape.

11. The crane in accordance with claim 1, wherein the horizontal beams or corner arms of two longitudinal structural part pieces to be connected to one another have end surfaces, wherein the end surfaces are end sides which can be clamped against one another with each of a first and a second plug-in cut-out in the tongue and the tongue receiver is spaced apart from the end surfaces such that a flush overlap can only be achieved under a preload by spreading apart the crossbar.

12. The crane in accordance claim 11, wherein the first plug-in cut-out in the tongue from the end surface of one of the corner arms or one of the horizontal beams having the tongue is smaller than a spacing of the second plug-in cut-out in the tongue receiver from the end side of the corner arm or horizontal beam having the tongue receiver.

13. The crane in accordance with claim 1, wherein the spreading device comprises adjustment means for adjusting at least a part of the crossbar in the longitudinal crossbar direction.

14. The crane in accordance claim 13, wherein the adjustment means comprise an adjustable tie rod, as well as an abutment which supports a first spreading part of the crossbar at an end side and supports the tie rod by which a second spreading part is adjustable at a spacing from the abutment.

15. The crane in accordance with claim 1, wherein the spreading parts of the crossbar have a wedge angle of a in a range from 0.5 degrees to 10 degrees, wherein the wedge angle can be one of between 1 degree to 5 degrees, and 2 degrees to 4 degrees.

16. The crane in accordance with claim 1, wherein the tongue and the tongue receiver comprise plug-in cut-outs, the plug-in cut-outs contoured to a shape and dimensions of the crossbar, and where the crossbar is plugged into the plug-in cut-outs with an exact fit.

17. The crane in accordance with claim 1, wherein the cross-section of each of the crossbar half-shells does not have a circular shape.

18. The crane in accordance with claim 1, where the substantially planar portions of the crossbar half-shells are positioned between the rounded portions of the crossbar half-shells.

19. The crane in accordance with claim 1, where the rounded portions of the crossbar half-shells are oriented away from one another and the substantially planar portions are positioned between the rounded portions.

Description

BRIEF DESCRIPTION OF FIGURES

(1) FIG. 1 shows a schematic side view of a tower slewing crane in accordance with an advantageous embodiment of the invention whose tower is composed of a plurality of tower pieces which can be tensioned with one another by means of a mortise and tenon joint with a spreadable crossbar.

(2) FIG. 2 shows a schematic sectional view of a mortise and tenon joint and its crossbar for connecting two tower pieces, wherein, in accordance with an advantageous embodiment of the invention, the two crossbars are each composed of two spreading wedges of half-shell shape.

(3) FIG. 3 shows a side view of a crossbar from FIG. 1 in the widened or spread apart or wedged state.

(4) FIG. 4 shows a side view of the crossbar from FIG. 1 in the released or non-widened state.

(5) FIG. 5 shows an end-face view of the crossbar from FIG. 1 which shows the cross-sectional contouring of the spreading wedges of the crossbar of half-shell shape.

(6) FIG. 6 shows a cross-section of the tongue receiver of a corner arm with the plug-through cut-outs provided therein for the crossbar of the mortise and tenon joint.

(7) FIG. 7 shows a cross-section under tension of the tongue which can be inserted into the tongue receiver of the corner arm of FIG. 6.

(8) FIG. 8 shows a perspective representation of the corner arms of two tower pieces placed next to one another in the open, non-latched state, wherein the plug-through cut-outs in the cross-arm, which are of an elongate hole type in cross-section, and the holder for the holding abutment of the crossbars are shown.

(9) FIG. 9 shows a cross-section through the mortise and tenon joint between two tower pieces and their crossbars which are, in accordance with a further advantageous embodiment of the invention, composed of a respective three spreading wedges.

(10) FIG. 10 shows a side view of a crossbar from FIG. 9, wherein the three spreading wedges are shown in the spread, widened state.

(11) FIG. 11 shows a side view of the crossbar from FIG. 10 in the unspread, non-wedged state.

(12) FIG. 12 shows an end-face representation of the crossbar from FIGS. 10 and 11 which show the cross-sectional contouring of the crossbar and its spreading wedges.

DETAILED DESCRIPTION

(13) As FIG. 1 shows, the crane 1 can comprise as longitudinal structural parts 2 a tower 3, on the one hand, and a boom 4 connected in an articulated manner thereto and projecting therefrom, on the other hand, wherein the tower 3 and the boom 4 are each composed of a plurality of tower pieces or boom pieces 3a, 3b . . . 3n or 4a, 4b . . . 4n respectively. The tower 3 and the boom 4 and their pieces can each be formed as lattice supports. The tower pieces 3a, 3b . . . 3n, for example, can each comprise four corner arms 5 which extend in the longitudinal tower direction and which can be connected to one another by cross-connectors in the form of transverse or diagonal bars so that the tower pieces and thus the tower 3 in its entirety have a quadrangular cross-section. In a similar manner, the boom or a respective boom piece can comprise three horizontal beams which are arranged in the longitudinal boom direction and which can be connected to one another by corresponding cross-connectors in the form of transverse and diagonal bars so that the boom in its entirety has a triangular cross-section. It is, however, understood that other cross-sectional shapes having different corner arm arrangements or horizontal beam arrangements can be provided.

(14) As FIG. 2 shows, the tower pieces 3a and 3b can be connected to one anotherin an analog manner also the boom piecesby means of mortise and tenon joints 6 in the region of the corner arms 5, wherein the corner arm of a first tower piece 3a can comprise a tongue 7 which projects axially at the end face and which can move with an exact fit into a tongue receiver 8 at the end of the corner arm 5 of the other tower piece 3b. The named tongue receiver 8 can be a hole which is open at the end face, which extends in the longitudinal direction of the corner arm 5, which can be provided in the inner space of the corner arm 5 or in a connection piece welded thereto or fixed in another manner and which extends in the longitudinal direction of the corner arm 5. The tongue receiver 8 is adapted with respect to its cross-section and its dimensions to the tongue 7 so that the tongue 7 is seated with an exact fit at the tongue receiver 8.

(15) As FIG. 8 shows, the front faces at the end side of the corner arms 5 of the tower pieces 3a and 3b to be connected can abut one another when the mortise and tenon joint is moved in or the power pieces are positioned next to one another.

(16) To secure the mortise and tenon joint 6 and to hold the tower pieces 3a and 3b at one another by a compressive force or to clamp the connection surfaces of the tower pieces 3a and 3b toward one another, the tongues 7 of the mortise and tenon joint 6 are secured and clamped in the tongue receiver 8 by means of crossbars 9. As FIG. 2 shows, two crossbarsoptionally also more than two or also only one crossbarcan be provided per mortise and tenon joint 6 whose longitudinal crossbar axis 25 can extent transversely to the longitudinal tongue axis or transversely to the longitudinal corner arm axis or transversely to the longitudinal tower axis through the respective tongue 7 and also through the respective tongue receiver 8. The tongue 7 and the tongue receiver 8 have plug-in cut-outs 20 and 21 respectively for this purpose which can each be formed as passage cut-outs and which can beapproximatelyaligned with one another or overlap one another so much when the tongue 7 has been moved into the tongue receiver 8 that the crossbar 9 can be plugged through the plug-in cut-outs 20 and 21.

(17) As FIG. 8 shows, the named plug-in cut-outs 20 and 21 respectively can be contoured differently from the circular shape and can in particular be shaped as approximately oval or of elongate hole shape. The cross-sectional contouring of the named plug-in cut-outs 20 and 21 is in this respect adapted in shape to the cross-sectional contour of the crossbar 9 which can be spread apart and is also adapted with respect to the dimensions such that the crossbar 9 can be plugged in with an exact fit and can be spread apart.

(18) As FIGS. 3 to 5 show, the crossbar 9 can likewise haveviewed in its entiretyan approximately oval cross-sectional contouring, wherein the crossbar 9 can be composed of two spreading parts 11 and 12 which are both respectively contoured as elongate and which approximately form half tongues which supplement one another. The two spreading parts 11 and 12 are in particular each contoured in wedge shape and are formed as half-shells which each have a crescent-shaped or half-oval shaped cross-section. Viewed over the length, each of the spreading parts 10 and 11 tapers toward one side so that a wedge-shaped contouring is produced, wherein the oblique surfaces 14 of the two half-shells which are preferably planar lie on one another so that the crossbar 19 overall has the named oval cross-sectional contour. Viewed overall, the crossbar 9 forms a plug-in pin or a plug-in tongue which can be plugged transversely through the connection region of the corner arms.

(19) As in particular FIGS. 2 and 3 show, the wedge-shaped half-shells, i.e. the spreading parts 10 and 11, are oriented in opposite directions from one another, i.e. the thinner end of the one spreading part 10 faces one end of the crossbar 9, whereas the other spreading part 11 faces the oppositely disposed end. The oblique surfaces 14 which lie on one another form a slanted longitudinal section or a slanted longitudinal section plane through the crossbar 9 which extends inclined at an acute angle toward the longitudinal crossbar axis 25.

(20) As a comparison of FIGS. 3 and 4 makes clear, the crossbar 9 can be spread apart in that the two wedge-shaped spreading parts 10 and 11 are displaced relative to one another in the longitudinal direction of the crossbar so that they can slide off one another on their oblique surfaces. The crossbar 9 is hereby widened transversely to its longitudinal axis, i.e. the diameter dimension increases in a plane perpendicular to the oblique surfaces. The diameter measurement transversely to the named wedge action plane, however, remains the same.

(21) The crossbars 9 are arranged in the corner arms or the elongate hole-like plug-in cut-outs 20 and 21 are oriented such that the spreading apart of the crossbar 9 takes place in the direction of the longitudinal axis of the corner arms 5, i.e. the two corner arms 5 to be connected to one another are drawn or pressed toward one another by spreading apart the crossbars 9 so that they are held on one another by compressive forces.

(22) To be able to displace the spreading parts 10 and 11 relative to one another in the longitudinal crossbar direction and thus to be able to spread the crossbar 9 apart, the two spreading parts 10 and 11 are fixed to an abutment 24 at the end face, wherein an adjustment means 22, for example in the form of a screw 23, is associated with at least one of the spreading parts 11 and the spacing of the spreading part 11 from the abutment 24 can be varied by means of it. As FIG. 2 shows, one of the spreading parts 12 can in particular be fixedly fastened to the abutment 24 at the end face, whereas the other spreading part can be drawn onto the abutment 24 by a screw 23 or can be moved further away from the abutment 24 on a loosening of the screw 23 to reach the released or non-spread apart configuration shown in FIG. 4 or, conversely, to reach the spread apart configuration shown in FIG. 3.

(23) The named abutment 24 can be secured at the corner arm 5 by holding means 26, for example in the form of a screw, or can be fastened to a securing hoop 27 attached thereto, cf. FIG. 8.

(24) The named abutment 24 can be configured in the form of a holding plate which surrounds the corner arm 5 at the peripheral side, cf. FIG. 6 or FIG. 2, for example in the form of an L-shaped metal holding plate, cf. FIGS. 2 and 6.

(25) As FIGS. 9 to 12 show, the crossbar 9 can also be composed of more than two spreading parts and can in particular comprise a middle wedge 13 which can be arranged between two spreading wedges 11 and 12 which can have the same properties of the previously described half-shells of the previous embodiment. The two outwardly disposed spreading parts 11 and 12 in this respect bound a V-shaped intermediate space between them in which the named middle wedge 13 is received.

(26) In a similar manner to the previously described embodiment, a screw 23 with which the middle wedge 13 can be adjusted with respect to the abutment 24 can be provided as an adjustment means 22 for spreading apart the crossbar 9. In another respect, this three-part configuration of the crossbar 9 corresponds to the previously described embodiment so that reference can be made thereto.

(27) The connection of the longitudinal structural part pieces to be connected to one another works via a clamping effect due to the formation of sliding and spreading planeor a plurality of such sliding and spreading planes. In this respect, tolerances can be taken up by the individual parts and a pre-loaded connection generating compressive force can nevertheless be achieved. A rotation of the individual parts in the installed state is prevented by the cross-sectional shape which differs from the circular shape and which is in particular approximately oval and it is additionally ensured that the crossbars 9 are installed in a correctly oriented manner. The individual parts of the crossbar 9 center themselves due to the shown shape of the individual parts.

(28) To overcome the friction on the spreading apart of the crossbars 9, the crossbar 9 or its spreading parts 11, 12 and 13 can be provided with a friction-reducing surface coating. A greasing can optionally also be provided.

(29) A pre-load in the corner arm of a connected tower piece or boom piece can be achieved by the spreadable crossbar 9. The operation is in this respect similar to a pre-loaded screw connection. The pre-load by the clamping effect as a consequence of the spreading apart of the crossbar 9 can be achieved by a simple adjustment screw 23 which is screwed at the end face into one of the spreading parts 11, 12 or 13, wherein a release of the connection during operation is made impossible by the applied pre-load.