LU85934A1 - TELESCOPIC BOOM OF A TOWER CRANE OR THE LIKE - Google Patents

Description

& f - 2 - The invention relates to a telescopic boom of a tower crane or the like, of the type comprising at least two boom sections sliding one inside the other and a carriage movable on each of the sections, each section of arrow î. being provided with two tracks extending in the longitudinal direction of the arrow, the tracks r located on the same lateral side of the arrow being transversely offset, the carriage comprising a body and at least one pair of devices of support located on each lateral side facing each other, each support device of a pair comprising at least one support member, connection means between this support member and the body allowing transverse movement of this member and therefore of this support device relative to the body and at least one rolling roller mounted for rotation on the support and rolling on the rolling track of a boom section on the corresponding side of the boom, the boom comprising means for controlling the transverse movement of the support members of a pair of support devices at the point where the carriage passes from one boom section to the other so that the running roller mounted on r the support members pass from a track of the first section to a track of the other section.

Arrows like this allow the carriage to roll the full length of the boom for any position in the boom sections. The carriage can roll both on the foot section and on the tip section without the latter having to be removed or retracted at the same time.

Arrows of the kind in question also allow a so-called closed construction of the boom sections. In the retracted boom position, the foot section can completely surround the tip section.

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The boom sections are of a much simpler construction and above all can be lighter when the construction is closed instead of being open.

This last advantage is especially important for long booms comprising for example three or more sections.

An arrow of this kind is known from French patent no. 2,211,393.

In this arrow, all the tracks are located along their entire length at the same level. The rollers of the carriage are mounted each time on a support piece which is connected to the body of the carriage by a deformable parallelogram making possible a transverse translational movement of the corresponding roller. This parallelogram has two end of travel positions which each correspond to a position of the roller connected to it on one of the different tracks of the boom sections. The movement of the deformable parallelogram from one end-of-travel position to the other is ensured automatically by feeler members associated with it and detecting the passage of the carriage from one boom section to another, these feeler members comprising a stop provided towards the end of the outer boom section and a cam cooperating with this stop when the carriage is about to pass from one boom section to the other, this cam being pivotally mounted on the body of the carriage and being connected by a lever to one of the links of the deformable parallelogram.

During each passage of the carriage from one boom section to the other, the rollers move transversely from one rolling track to another which. causes significant wear of the rollers and tracks.

In addition, during this transverse movement, axial forces act on the bearings of these rollers while these bearings are constructed to withstand forces (/ * r - A - radial. Premature wear of these rollers results.

The tracks of the different boom sections must necessarily be at the same level.

The links of the deformable parallelogram of ", each support device of the carriage moreover have the tendency to take the vertical position because of the weight - of the carriage and especially of the weight of the load which this carriage carries. When these links of the deformable parallelogram are are in one of the extreme positions, the corresponding roller will therefore be pushed with its outer flange against the raceway, which brakes the roller. When this link is in another extreme position, this roller will instead be pulled outwards and risk leaving the track.

When the rods of the parallelogram of a front pair or a rear pair of support devices move from one extreme position to the other, the body of the carriage makes a fairly large movement in height. A force - quite significant is therefore necessary to effect this change of position of the links and therefore for the passage of the carriage from one section to another, especially if the carriage carries a load.

The object of the invention is to remedy these drawbacks and to provide a telescopic boom of the kind mentioned above in which the transverse translation of the rolling rollers of the carriage, when this carriage passes from one section of boom to another, is obtained in a simple and effective way, without significant wear of the rollers or tracks and without requiring significant forces.

For this purpose, the telescopic boom comprises means for lifting the rollers of the support devices for a pair of their rolling tracks at the location

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* - 5 - where these track rollers must pass from the track of a boom section to the track of another boom section and at least during all the time that the means for transversely moving the devices' support are in action, means for lifting, part of which is mounted on the carriage and the other part of which is mounted at the above-mentioned location on the end of one of the sections, one of these parts comprising a pair of auxiliary tracks and the other part comprising rollers cooperating with these auxiliary tracks.

Since the rollers of the support devices are no longer in contact with their raceway during their transverse movement, this movement cannot cause any wear of these rollers and these paths.

For this transverse displacement, a very minimal displacement in height is sufficient. During this movement, the carriage is supported by the parts cooperating with each other means for lifting the rollers. These parts do not move transversely.

In a particular embodiment of the invention, the part of the lifting means which is mounted on one of the sections at the place where the carriage passes from one section to the other is mounted on the tip end of that of these sections which is located on the mast side of the crane.

In a remarkable embodiment of the invention, the rollers of the support devices for a pair of these devices are fixedly mounted in height relative to the body of the carriage, and the means for lifting these rollers are means for * lifting the body of the carriage.

Preferably, the auxiliary tracks form a pair of the running tracks mounted on the end of one of the sections and the auxiliary rollers are rollers of

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- 6 - bearing mounted on the carriage body.

In an advantageous embodiment of the invention, the means of connection between the support member of each support device and the body of the carriage allowing a transverse movement of the device relative to the body of the carriage comprises a guide mounted on the body and extending transversely and a member guided by this guide, member which carries the support member.

In an effective embodiment of the invention, the means for controlling the transverse movement of the support devices comprise a guide mounted at the place where the carriage passes from one boom section to the other on the boom section located mast side and a member guided by this guide, member which is mounted on the support device concerned.

In an embodiment of the invention preferably applied, the carriage comprises locking means for the support devices movable transversely relative to the body, these locking means preventing any transverse movement of the support devices towards the outside except when 'they have to change their track.

Other features and advantages of the invention will emerge from the description of a telescopic boom of a tower crane or the like according to the invention; this description is given below only by way of nonlimiting example and with reference to the attached drawings in - _ "which:

Figure 1 is a schematic elevational view of a telescopic boom according to the invention.

2 shows a section along line II-III of Figure 1 of a portion of the boom but on a larger scale and with the carriage in its raised position.

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3 shows a cross section of part of the boom of Figures 1 and 2 on the same scale as Figure 2 and with the carriage also in the raised position.

'Figure 4 is a plan view of the rear half of the carriage, on another scale, with the raceways in phantom.

Figure 5 is an elevational view of a detail of the carriage of Figure 4 on a larger scale.

Figure 6 shows a section along the line VI-VI of Figure 5 with dotted part of an auxiliary raceway.

In the different figures, the same reference notations designate identical elements.

The telescopic boom according to the figures is mounted in a known manner on the upper end of the mast, not shown in the figures, of a tower crane.

This arrow comprises two sections of closed construction, sliding one inside the other, that is to say an outer leg section 1, and a lower tip section 2.

'Each section 1 and 2 has a triangular cross section and is formed by two lower lateral sections 3, a crown section 4 and by tubes 5 connecting these different sections.

All profiles have a rectangular cross section.

The sections 3 of the section 2 are lower than the sections 3 of the section 1.

As is clear from FIG. 1, the boom sections 1 and 2 are constructed and mounted in such a way that the upper faces of the sections 3 are all located at the same level, the upper faces of the same lateral side of the boom being further shifted transversely but located in close proximity to one another.

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These upper faces form horizontal tracks 6 or 7 for the carriage 8.

In the figures, the tracks formed by the two sections 3 of the leg section 1 are indicated by the reference numeral 6, and the tracks formed by the sections 3 of the tip section 2 by the reference number 7.

The carriage 9 comprises a body 10 in which the pulleys 11 are housed for the lifting cable. This body 10 is fixed at the front and at the rear to a cable 12 to move the carriage 9 in both directions. The pulleys are driven and the carriage is moved in a known manner and the known means for carrying out this drive and or this movement are not shown in the figures for the sake of clarity.

Similarly, the extension and removal of the boom are carried out in a known manner. For the sake of clarity, the known means for sliding the section 2 relative to the section 1 are not shown in the figures, and roller trains 8 mounted on the leg section 1 to guide this section 2 in a known manner during this sliding only one is shown.

To the body 10 of the carriage 9 are connected four support devices 13, a pair at the front and a pair at the rear, the support devices for a pair being located opposite one another.

Each support device 13 comprises a vertical support member 14 formed by a tube and projecting upward relative to the body 10, a roller 15 mounted for rotation about a transverse axis relative to the arrow on the upper end of the support member 14, and a small carriage 16,17 constituted by a chassis 16 and four rollers 17, on which the lower end of the support member 14 t'i fn ,.

i. ' - 9 - is fixed.

The small carriage 16,17 of each of the four support devices 13 and mounted displaceably transversely on the body 10 by means of a guide constituted by a pair of rails at ü 18 closing the tracks for the rollers bearing 17, these rails extending parallel in the transverse direction with their openings facing one another, these rails being integral with the body 10 of the carriage 9.

A spring 19 mounted below the small carriage 16,17 around a rod 20 extending transversely relative to the body 10, on the one hand between a retaining plate 21 fixed by means of angles 22 with bolts 23 and nuts 24 at the outer end of the two rails 18 and on the other hand a projection 25 mounted on the chassis 16, projecting downwards and freely surrounding the rod 20, pushes the small carriage 16,17 and therefore the entire support device 13 in the transverse direction towards the middle of the body 10.

The retaining plate 21 carries the rod 20, keeps the free ends of the rails 18 at a distance from each other and prevents the small carriage 16, 17 from leaving the rails 18.

The movement of the support device 13 inwards is limited by a guide roller 26 mounted for rotation about a vertical axis in a support 27 mounted on the mast side on the support member 14 and rolling on a formed guide track by the vertical external lateral face 28 or 29 of a lateral profile 3 of the section 1 or of the section 2. The support member 14 is obviously located more outside of this lateral face 28 or 29 while the rolling roller 15 of the support device 13 rolls on the track

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-lüde bearing 6 or -7 of the corresponding profile 3.

At the tip end of the leg section 1, the two lateral sections 3 of this section are bevelled, so that the lateral face 28 of these sections 3 - joins at this end the lateral face 29 of the corresponding sections of the section peak 2.

"At the above end, that is to say where the„ support device 13 must pass from one section to another, the lateral face of the profiles 3 forms a guide ramp for the guide rollers 26 causing a transverse displacement of these rollers 26 and therefore of the support device 13 on which this roller 26 is mounted.

The boom comprises lifting means ensuring that at the time of its transverse displacement the support device 13 is slightly raised so that its running roller 15 no longer touches its running track 6 or 7.

These means comprise two auxiliary rolling tracks 30 mounted on the leg section 1 and auxiliary rolling rollers 31 cooperating with these auxiliary rolling tracks 30.

The two auxiliary rolling tracks are formed by the upper face of two support pieces 32 extending in the longitudinal direction of the leg section 1.

The two support pieces 32 are welded, at the tip end of the leg section 1, each to a longitudinal vertical support plate 33 which is in turn welded to two cross members 34 welded by their ends to the underside of the profiles 3 lower leg section 1.

The two ends of the support pieces 32 are at a corner, which means that in the longitudinal direction, the upper face of the support pieces, face forming a rolling track, rises at one end over a distance j in height and descends to the other end over the same distance while the underside of the support pieces 32 descends at one end over a distance in height and rises at the other end over the same distance.

On the body 10 of the carriage 9 are mounted four auxiliary rolling rollers 31, two at the front between the support members 14 of the front pair of support devices 13 and two at the rear, between the support members 14 of the rear pair of support devices 13.

The two auxiliary rolling rollers 31 on the same lateral side of the body 10 cooperate with the same auxiliary rolling track 30 but one after the other.

Each auxiliary roller 31 is mounted for rotation about a transverse horizontal axis in a bearing 35 mounted on a longitudinal tube 36 which is welded on the two rails 18 projecting relative to the body 10, on the corresponding lateral side and at the corresponding end of the body 10.

The aforesaid underside of the support pieces 32 forms a guide track 37 intended to cooperate with an elbow lever 39 of a locking mechanism 38 which can prevent a transverse movement towards the outside of a support device 13. This transverse movement is already thwarted but not made impossible by a spring 19.

Such a lever 39 is mounted for rotation about a horizontal axis transverse to the top of one of the rails 18 of each pair of rails 18 forming the guide for a small carriage 16,17.

One arm of each lever 39 extends above the rail 18 obliquely upwards, the free end of this arm being curved. The other arm of the lever 39 extends downward along the rail 18. A spring 40 mounted between the latter arm and a retaining plate 41 fixed to the rail 18 pushes this arm towards the rail 18. In the rest position f of the lever 39, that is to say in the position shown in FIGS. 5 and 6, the last arm is against the rail 18.

In this position the end of the arm forms a stop 42 cooperating with one of the fingers 43 of a plate 44 fixed to the lower part of the chassis 16 of the small carriage 16,17. This plate 44 has two fingers 43 protruding outside the guide formed by the two rails = 18.

When cooperating with the guideway 37, the upper arm of the lever 39 is tilted down, the other arm of this lever 39 is distant from the above-mentioned guide and no longer retains the fingers 43, and therefore no longer prevents a transverse displacement towards the outside of the small carriage 16,17 and therefore of the entire corresponding support device 13.

When the carriage 9 moves on the leg section 1, the rollers 15 of the four support devices 13 roll on the tracks 6. At the same time, the guide rollers 26 mounted on these support devices roll on the guide tracks 28 of this leg section 1, which prevents the support devices 13 of a front pair or a rear pair from moving away from each other. The support devices 13 of each pair are prevented from approaching one another by the locking devices 38 mounted between these devices and the body 10 of the carriage 9.

When the carriage 9 reaches the tip end of the leg section 1, the lever 39 of the two locking devices 38 locking the two front support devices 13 come into contact with the guide tracks 37 formed by the two support pieces 32. These levers 39 are tilted as clearly shown in FIG. 2 and the small carriages 16, 17 of the front support devices 13 are released.

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Almost at the same time, the two auxiliary rolling rollers 31 come into contact with the two auxiliary rolling tracks 30 and mount thereon. The rollers 15 of the support devices 13 before it is thus lifted from their race 6.

- The carriage 9 is still supported by the = leg section but the front of the carriage 9 is no longer supported by means of the support devices 13 but by means of the auxiliary rolling rollers 31 before. The height over which the front of the carriage 9 is lifted is very small, for example 0.5 to 0.9 cm and does not require significant forces, even if a load is carried by the carriage.

Immediately afterwards, the guide rollers 26 roll on the inclined ramp at the end of the lateral guide face 28 of the sections 3 of the leg section 1 up to the lateral guide faces 29 of the sections 3 of the tip section 2.

This change in the guide track of the guide rollers 26 results in a transverse movement of the two support devices 13 before one towards the other, movement which is assisted by the springs 19 pushing these support devices 13 inwards. . For security reasons, an external guide extending parallel to the end of one of the side faces 28 can optionally be mounted on the leg section 1 to force the guide rollers to follow the inclined end of the side faces 28 .

The transverse movement of the front support devices 13 is done without difficulty and without using the rollers 15 or the tracks 6 or 7, since these rollers 15 are no longer in

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- 14 - contact with these tracks.

This transverse movement is finished when the front levers 39 and the auxiliary auxiliary rollers 31 reach the corner end of the tip of the arrow of the support pieces 32.

At this end, the lever 39 on each side of the carriage 9 returns to its initial position and its lower arm enters between the two fingers 43 of the plate 44 fixed to the support device 13 on the corresponding side, locking this device in its new position, the auxiliary running rollers 30 before descend to their initial height but on the running tracks 7 of the tip section 2 instead of the running tracks 6 of the foot section 1.

The change of track of the support devices 13 of the rear pair is done in the same way as the change of track described above of the support devices 13 of the front pair.

The change of track of the support devices 13 is also done in a similar manner when the carriage passes from the tip section 2 to the foot section 1 but the transverse movement of the support devices 13 is done in the direction of the outside, the devices of a front or rear pair moving away from each other. During this passage from section 2 to section 1, the support devices 13 before resp. rear are lifted, move outward, then descend to their original height. During this time, the corresponding guide rollers pass from a guide track 29 to a guide track 28 and the body of the carriage hangs by means of the auxiliary rollers 30 before resp. rear, to support pieces 32.

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The ^ passage of the carriage from one boom section to another is done in a simple manner, without significant wear and without requiring great forces.

It should be understood that the invention is in no way limited to the embodiment described above and that many modifications can be made to it, in particular as to the form, the arrangement, the composition and the number of elements. involved in its realization.

In particular, the number of boom sections is not limited to two. The invention lends itself very well to being applied in arrows with three or more than three sections. The mat side end of each section is provided with two support parts forming auxiliary rolling tracks and the passage of the carriage from one section to the other takes place in the manner described above.

The blocking or locking device blocking the small carriages must obviously be adapted to allow as many locking positions as there are boom sections.

Locking by this device does not necessarily have to be in both transverse directions.

It is sufficient that the device in action prevents movement of the small carriage outwards, movement inwards being made impossible by the guide roller.

The blocking or locking device need not necessarily include a lever cooperating with the fingers of a plate .11 may also include pins pivotally mounted and which can enter holes in the guide rails of the small carriage.

The tracks of the boom sections need not be located at the same level. When the tracks are at a different level, h j - 16 - the shape of the auxiliary tracks must be adapted, one end having to cause a difference in height different from the other end.

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Claims (17)

1. Telescopic boom of a tower crane or the like, of the type comprising at least two boom sections sliding one inside the other and a carriage displaced on each of the sections, each boom section being provided with two raceways extending in the longitudinal direction of the boom, the raceways located on the same lateral side of the boom being transversely offset, the carriage comprising a body and at least one pair of support devices located on each side lateral opposite one another, each support device of a pair comprising at least one support member, connection means between this support member and the body allowing transverse movement of this member and therefore of this support device with respect to the body and at least one rolling roller mounted for rotation on the support and rolling on the rolling track of a section of boom on the corresponding side * of the boom, the boom comprising means for r order the transverse movement of the support members of a pair of support devices at the point where the carriage passes from one boom section to the other so that the rolling roller mounted on the support members passes from a track of the first section to a track of the other section, characterized in that it comprises means for lifting the track rollers of the support devices of a pair of their track tracks with the place where these track rollers must pass from the track of one section of boom to the track of another section of boom and at least during the whole time that the means for transversely displacing the devices support are in action, means for lifting, a part of which is mounted on the carriage and the other part of which is mounted at the above-mentioned location on the end of one of the sections, one of these parts comprising a pair auxiliary channels and the other part includes ant rollers cooperating with these auxiliary tracks. 2. Telescopic boom according to claim 1, characterized in that the part of the lifting means which * is mounted on one of the sections at the place where the carriage passes from one section to the other is mounted on the end of point of the one of these sections which is located on the mast side of the crane. 3. Telescopic boom according to either of claims 1 and 2, characterized in that the rollers of the support devices of a pair of these devices are fixedly mounted in height relative to the body of the carriage , and the means for lifting these rollers are means for lifting the body of the carriage. 4. Telescopic boom according to claim 3, characterized in that the auxiliary tracks form a pair of rolling tracks mounted on the end of one: sections and the auxiliary rollers are rolling rollers mounted on the body of the carriage. 5. Telescopic boom according to claim 4, characterized in that the rolling tracks of the different boom sections are located at the same level and the auxiliary tracks form at their two ends ramps. Inclined in opposite directions and spanning the same difference in level . 6. Telescopic boom according to either of Claims 4 and 5, characterized in that the carriage comprises two pairs of support devices, one at the front and one at the rear of the carriage, the means for lift comprising at least two pairs of auxiliary rollers, one / at the front and one at the rear of the body of the carriage, the rollers ts \ \ - 19 - of a pair being mounted at a fixed distance one of the other in the transverse direction. 7. Telescopic boom according to either of claims 1 to 6, -caractérisée in that the connection means between the support member of each device - support and the carriage body allowing a transverse movement of the device relative to the body of the carriage comprise a guide mounted on the body and extending transversely and a member guided by this guide, member which carries the support member. 8. Telescopic boom according to claim 7, characterized in that the guide comprises at least one rolling track and the guided member comprises a small carriage having at least one rolling roller rolling on this track. 9. Telescopic boom according to either of claims 1 to 8, characterized in that the means for controlling the transverse movement of the support devices comprise a mounted guide, at the place where the carriage passes from a section boom to another, on the boom section located on the mast side and a member guided by this guide, member which is mounted on the support device concerned. 10. Telescopic boom according to claim 9, characterized in that each boom section comprises two longitudinal sections, each section having a face whose transverse direction extends in the transverse direction of the arrow, this face forming a track-of " bearing, and a face facing the outside, this face of the section located on the mast side forming at the end remote from the mast a ramp extending inwards forming the guide of the means for controlling the transverse movement A support device. F - 20 - 11. Telescopic boom according to either of claims 9 and 10, characterized in that the guided member means for controlling the transverse movement of a support device comprises a guide roller mounted on the member support of this device, and cooperating with the guidance of the above means. • "12. Telescopic boom according to either of claims 9 to 11, characterized in that the carriage comprises a spring by support device, mounted between this device and the body of the carriage, and exerting on the device supports a transverse force towards the middle of the body. 13. Telescopic boom according to either of claims 1 to 12, characterized in that the carriage comprises locking means for the support devices movable transversely relative to the body, these locking means preventing any transverse movement towards the outside of the support devices except when they have to change track. 14. Telescopic boom according to claims 4 and 13, characterized in that the locking means comprise a control lever by carriage support device "mounted on the body and cooperating with the auxiliary path with which an auxiliary roller cooperates during passage from the support device for the track of one boom section to the track of another section. 15. Telescopic boom according to claim 14, characterized in that the auxiliary track has wedge-shaped ends. 16. Telescopic boom according to claims 8, and 14, characterized in that the locking means for a support device comprise a member of a retaining element cooperating with this locking member, element mounted on the small carriage of connection means between the support member of the support device and the body of the carriage. 17. Telescopic boom of a tower crane or the like as described above or shown in the accompanying drawings. ^ Aàaxjuu "a