EP2422039A1

EP2422039A1 - Telescopically extending shaft

Info

Publication number: EP2422039A1
Application number: EP10766690A
Authority: EP
Inventors: Pentti KUIVAMÄKI; Mikko Lindeman
Original assignee: Unisto Oy
Current assignee: MOVAX Oy
Priority date: 2009-04-20
Filing date: 2010-04-20
Publication date: 2012-02-29
Also published as: FI121893B; FI20090150A0; WO2010122212A1; EP2422039A4; FI20090150A

Abstract

Telescopically extending shaft that comprises parts (1 — 3) conveying rotation movement and axial force and the extending and shortening of which shaft is achieved with the help of a power unit, such as a hydraulic cylinder (8) moving in one axial direction and the moveable, separate parts (1 - 3) of which shaft moving telescopically in relation to each other are arranged to move in an as such known way by using pulling elements (6); (7) and sheaves (26); (27) attached to the parts (1) and (2) adjusted in such a way that the first part (1) that can be moved straight with the help of a power unit (8) causes the movement of the second part (2) through the pulling element (6) and the sheave (26) attached to the first part and the sheave (27) attached to the second part (2) causes the movement of the third part (3) through the pulling element (7) starting from the first part (1). In order to retract the parts (1 - 3) of the shaft the arrangement comprises the first part (1) that can be pulled to a retraction direction with the help of the power unit (8) and comprises a pulling element (24) the first end of which is attached to the moveable part (25) of the power unit in which case the second end of the pulling element (24) is attached to the third part (3) in such a way that it first passes round the sheave (23) located fixed inside the shaft and then passes round the sheave (22) attached to the moveable part of the power unit (8).

Description

TelescopicaUy Extending Shaft

This invention relates to a shaft that can be telescopically extended which shaft comprises parts that convey rotation movement and axial force and the extending and shortening of which shaft has been achieved with the help of a power unit, such as a hydraulic cylinder moving in axial direction and the parts of which shaft that move telescopically in relation to each other are arranged to move in an as such known way by using pulling elements and sheaves attached to the parts adjusted in such a way that with the help of a power unit the first part that can be moved straight causes the movement of the second part through the pulling element and the sheave connected to the first part and the sheave attached to the second part causes the movement of the third part through the pulling element starting from the first part.

Previously arms according to the above mentioned preamble that can be telescopically extended are known in the cranes, such as in truck cranes and timber loaders in which usually the outermost arm is arranged to be extending so that an accurate directional movement could be achieved and also due to a reason that with extending more extent can be achieved. In these solutions the needed cylinder can often be seen outside the parts. The cylinder pushes and retracts only one telescopic part. In some cranes the expulsion of several nested parts is realized according to the above mentioned preamble with one cylinder and with the help of pulling elements and sheaves. The telescopic arms in their service position are however so erect that the pulling of the parts within each other is not needed when they come down with gravitational force. Also a solution is known regarding the retraction in which solution the other end of the pulling element is attached to the outermost telescopic part and with the pulling element and for example a winch the parts are pulled back to be within each other.

Regarding earth boring bits, the outlet of several telescopic parts of the shaft of the earth boring bit is known with the gravitational force and their retraction occurs with the help of a pulling element and a winch, the publications US 5, 746, 277 and 4, 877, 091 being as examples. The usage of these is thus limited only to vertical drillings.

In the known solutions there is a disadvantage regarding directional limitation, hi the known earth boring bits the extending of the shaft functions only when the shafts are upright enough. Only drilling downwards is possible because there is no expulsion of the telescopic parts. This restricts the usage of the earth boring bits in such a way that for example horizontal drillings underneath a road cannot be performed. On the other hand some telescopic shafts consisting of several parts have the disadvantage regarding the retraction if the shaft cannot be turned to a vertical direction in such a way that the gravitational force would take care of the retraction.

With the telescopic shaft according to the invention the above mentioned problems can be solved and it is characteristic for the arrangement according to the invention that in order to retract the parts of the shaft the arrangement comprises the first part that can be pulled to the retraction direction with the help of a power unit and the arrangement comprises a pulling element the first end of which is attached to the moveable part of the power unit in which case the second end of the pulling element is attached to the third part in such a way that it first passes round the sheave located fixed inside the shaft and then passes round the sheave attached to the moveable part of the power unit.

The advantage of the telescopic shaft arrangement according to the invention is the fact that with a dual-purpose hydraulic cylinder having the length of one movement cycle a movement comprising three cycles can be realized outwards in a controllable manner and back inwards in a controllable manner. As a solution applied to the shaft of an earth boring bit one can drill with the earth boring bit to any angle because a feed motion can be given to a drill head with a movement directed outwards and needed feed force can also be combined to it. With the solution according to the invention the outer surfaces of the telescopic parts stay as completely free surfaces because all the equipments needed for the moving can be adjusted inside the telescopic parts.

In the following the invention is described more detailed by referring to the accompanying drawing in which

Figure 1 shows an earth boring bit as a side view.

Figure 2 shows an earth boring bit when its shaft is partly extruded.

Figure 3 shows the inner structure of the telescopic parts and the push/pull cylinder.

Figure 4 shows a cross section of the telescopic parts. Figure 5 shows diagrammatically an expulsion of the telescopic parts. Figure 6 shows diagrammatically a retraction of the telescopic parts. Figure 7 shows a push/pull cylinder.

In the figure 1 there is an earth boring drill equipped with a spiral cutter 13 the shaft 14 of which drill is attached to a connector 19 attached to the end of the outermost part 3 that can be moved telescopically. The parts 2 and 3 are other parts that can be moved telescopically. The parts 13, 14, 19, 3, 2 and 1 rotate during the drilling. The rotation occurs from the other end of a line haul section that does not rotate to which end a rotator 18, such as a rotator run by a hydraulic motor that can be used with a hydraulic motor has been installed. The earth boring bit is attached to a digging machine through a unit 16 that can be moved on top of the line haul section 5. With the help of the hydraulic cylinder 17 the earth boring bit can be moved in relation to the unit 16. The rotation of the round line haul section 5 in relation to the unit 16 is prohibited with a groove located in the unit 16 and with a bar 15 that is equivalent to it which bar is attached to move on the surface of the line haul section 5.

In the figure 2 the telescopic parts 1 - 3 are somewhat extruded like they are also in the figure 3. The pull/push cylinder 8 belonging to the equipment is installed in such a way that the head of the piston rod 9 is locked to a rotating flange 21 adjusted to the head of the line haul section 5 which flange cannot move in axial direction but can rotate rotated by a rotator 18, such as the telescopic parts 1- 3, too. The right-hand end of the cylinder part 8 of the pull/push cylinder is attached to the rear end of the first telescopic part 1 for example by using a pin 10. The first telescopic part 1 thus always moves when the cylinder 8 moves. A sheave 26 is attached to the left end of the cylinder part 8 through which sheave a pulling element 6 passes round, the pulling movement of which pulling element pushes the other part 2 outwards. The one end of the pulling element 6 is attached to a flange 21 staying at its place with the help of a short spring arrangement 20 and the other end is attached to the rear end of another part 2 to a location 12. A sheave 27 belongs to another part 2 to its left end through which sheave a pulling element 7 passes round, one end of which is attached to the rear end of the first part 1 and the other end to the rear end of the third part 3, to the location 1 1. In this way the expulsion occurs with a movement of one cylinder 8 and the outlet movement is three times compared with the movement of the cylinder 8.

The figure 4 shows how the sheaves are located to the intermediate spaces of the telescopic parts 1 - 3. Also the pulling elements naturally move in them. In order to achieve a symmetrical thrust motion the parts that are related to the expulsion can also be located to the intermediate spaces of the other, opposite side. Thus no equipment related to the pulling/pushing arrangement can be seen outside the telescopic parts 1 - 3.

The figure 5 shows diagrammatically the expulsion of the telescopic parts 1 - 3. With the movement of the cylinder 8 only the part 1 is pushed. The pulling elements 6 and 7 are for example chains or wire ropes.

The figure 6 shows diagrammatically the retraction of the telescopic parts 1 - 3. The retraction arrangement is adjusted inside the telescopic parts 1 - 3 in such a way that it is located also inside the smallest part 3 when the part 3 has been pulled in. The cylinder 8 pulls directly the first part 1 in, in the diagram the attachment point 28. Further only one pulling element 24 belongs to the retraction which pulling element is adjusted in such a way that its one end is attached to the moveable part of the cylinder 8, point 25 and the other end is attached to the third part 3, most advantageously to its front part, point 29. The pulling element further passes round through the sheave 22 attached to the cylinder 8 and moving along the cylinder and passes round through the fixed sheave 23 that can be arranged to stay at its location in such a way that the piston rod 9 of the cylinder 8 goes through the cylinder 8 and the mentioned sheave 23 is attached to the end of the piston rod. Alternatively this sheave 23 can be installed to be fixed inside the parts 1 - 3 with the help of some other attachment arrangement, such as to the end of the bar starting from the flange 21, but the first-mentioned solution is the most simple one.

When the parts 1 - 3 are being extruded, the pulling element 24 of the retraction gives a part of itself with the same speed to the part 3. The cylinder 8 can also be attached in such a way that the cylinder part 8 stays at its place and its other end is attached to the flange 21. The piston rod, moves inside the parts 1 - 3 and the moveable sheaves 26 and 22 are then attached to the piston rod and the fixed sheave 23 is attached to the cylinder 8. Although in the diagram 6 only the telescopic parts 1 and 3 are retracted, also the part 2 will be pulled because the pulling element 7 of the pushing^arrangement according to the figure 5 retracts the part 2 while the parts 1 and 3 are being retracted.

The invention is not limited to be only a shaft of a earth boring bit but many other tools and objects can be attached to the end of the shaft.

Claims

1. Telescopically extending shaft that comprises parts (1 - 3) conveying rotation movement and axial force and the extending and shortening of which shaft is achieved with the help of a power unit, such as a hydraulic cylinder (8) moving in one axial direction and the moveable, separate parts (1 - 3) of which shaft moving telescopically in relation to each other are arranged to move in an as such known way by using pulling elements (6); (7) and sheaves (26); (27) attached to the parts (1) and (2) adjusted in such a way that the first part (1) that can be moved straight with the help of a power unit (8) causes the movement of the second part (2) through the pulling element (6) and the sheave (26) attached to the first part and the sheave (27) attached to the second part (2) causes the movement of the third part (3) through the pulling element (7) starting from the first part (1), characterized in that in order to retract the parts (1 - 3) of the shaft the arrangement comprises the first part (1) that can be pulled to a retraction direction with the help of the power unit (8) and comprises a pulling element (24) the first end of which is attached to the moveable part (25) of the power unit in which case the second end of the pulling element (24) is attached to the third part (3) in such a way that it first passes round the sheave (23) located fixed inside the shaft and then passes round the sheave (22) attached to the moveable part of the power unit (8).

2. Shaft according to the claim 1, characterized in that the pulling elements (6); (7) and sheaves (26); (27) related to the expulsion of the parts (1 - 3) of the shaft are located to the intermediate spaces formed between the parts (1 - 3) which intermediate spaces have been achieved by adjusting a sufficient size difference for the cross section measurements of the profile forms of the parts (1 - 3).

3. Shaft according to the claim 1, characterized in that the movement arrangement of the parts (1 - 3) related to the shortening of the shaft is adjusted to the innermost part of the shaft in which case it is located to essentially function inside the smallest part (3) regarding its cross section measurements.

4. Shaft according to the claim 1, characterized in that a fixed sheave (23) related to the retraction of the parts (1 - 3) is attached to the end of the piston rod (9) going through the cylinder part (8) of the power unit.

5. Shaft according to the claim 1, characterized in that the pulling elements (6); (7); (24) are chains or wire ropes.