Crane telescope locking device

Abstract

A crane telescope locking device includes a control device which is hydraulically in contact with a telescoping cylinder of a crane telescope and, for the purpose of actuating, with at least one cylinder lock hydraulic cylinder and includes a valve which is open in its inactivated resting state and thus opens a fluidic connection between the telescoping cylinder and the at least one cylinder lock hydraulic cylinder. A telescoping cylinder (6) of a crane includes such a crane telescope locking device.

Claims

1. A crane telescope locking device for a crane telescope having a telescoping cylinder and telescopic sections, the locking device comprising: at least one first hydraulic cylinder configured to releasably couple the telescoping cylinder and a telescopic section of the telescopic sections to each other; and a control device in hydraulic contact with the telescoping cylinder and the at least one first hydraulic cylinder, wherein the control device is configured to actuate the at least one first hydraulic cylinder by controlling hydraulic fluid flow from the telescoping cylinder to the at least one first hydraulic cylinder, wherein the control device comprises a valve which is open in an inactivated resting state to fluidically connect the telescoping cylinder to the at least one first hydraulic cylinder, wherein the control device comprises a return line comprising at least one closing valve and a bypass which bypasses the at least one closing valve, the bypass comprising the valve, and wherein hydraulic fluid is fed in the direction from the telescoping cylinder toward the at least one first hydraulic cylinder via the bypass when the at least one closing valve is closed and the valve is open in the inactivated resting state.

2. The crane telescope locking device according to claim 1, wherein the bypass additionally comprises a pressure sequence valve configured to open the return line for hydraulic fluid flow in the direction from the telescoping cylinder toward the at least one first hydraulic cylinder and/or open the bypass above a defined pressure.

3. The crane telescope locking device according to claim 1, wherein the return line comprises a pressure reservoir configured to receive the hydraulic fluid from the at least one first hydraulic cylinder before the hydraulic fluid is fed back into the telescoping cylinder.

4. The crane telescope locking device according to claim 1, wherein the control device comprises a feed line via which the hydraulic fluid is fed from the telescoping cylinder to the at least one first hydraulic cylinder.

5. The crane telescope locking device according to claim 4, wherein the feed line comprises a pressure reservoir configured to receive the hydraulic fluid from the telescoping cylinder before the hydraulic fluid is fed to the at least one first hydraulic cylinder.

6. The crane telescope locking device according to claim 1, further comprising at least one second hydraulic cylinder configured to operate a section lock to releasably couple the telescopic sections to each other.

7. A telescoping cylinder of a crane, comprising: a first cylinder part comprising a fastening portion configured to fasten the telescoping cylinder to a base of a crane telescope; a second cylinder part configured for movement relative to the first cylinder part, the second cylinder part comprising a crane telescope locking device; and an annular space between the first cylinder part and the second cylinder part, wherein the crane telescope locking device comprises: at least one cylinder lock first hydraulic cylinder configured to releasably couple the second cylinder part and a telescopic section of the crane telescope to each other; and a control device in hydraulic contact with the annular space and the at least one first hydraulic cylinder, wherein the control device is configured to actuate the at least one first hydraulic cylinder by controlling hydraulic fluid flow from the annular space to the at least one first hydraulic cylinder, wherein the control device comprises a valve which is open in an inactivated resting state to fluidically connect the and annular space to the at least one first hydraulic cylinder, wherein the control device comprises a return line comprising at least one closing valve and a bypass which bypasses the at least one closing valve, the bypass comprising the valve, and wherein hydraulic fluid is fed in the direction from the annular space toward the at least one first hydraulic cylinder via the bypass when the at least one closing valve is closed and the valve is open in the inactivated resting state.

Description

(1) FIG. 1 schematically shows a preferred embodiment of the crane telescope locking device in accordance with the invention, which comprises the hydraulic cylinder 5 which is designed to activate a lock (not shown) between the telescopic sections 1, 2 and 3 of the telescope 4. In addition, the locking device also comprises a hydraulic cylinder 7 which can be indirectly coupled to one of the telescopic sections 1, 2 via engagements. The corresponding telescopic section 1, 2 is thus in turn fixedly coupled to the extending and retracting part 19 of the telescoping cylinder 6 and can be telescoped in and/or out together with the part 19 relative to the base section 3. When telescoping in and out, the moving part 19 of the telescoping cylinder 6 is moved relative to the piston rod 17 which is fixedly connected to the base section 3 via the interface 18. It should be noted at this juncture that the arrangement of the telescopic sections 1, 2 and 3 and hydraulic cylinders 5 and 7 is shown purely schematically and that the engagements necessary for the ultimate coupling processes can comprise an additional mechanism (not shown) between the hydraulic cylinders 5 and 7 on the one hand and the telescopic sections 1, 2 and 3 on the other.

(2) The control device 8 designed to activate the hydraulic cylinders 5 and 7 is hydraulically connected both to the hydraulic cylinders 5 and 7 and to the piston-rod-end annular space 20 of the telescoping cylinder 6 and retrieves the hydraulic fluid necessary for activating the hydraulic cylinders 5 and 7 from the annular space 20 and also feeds it back there again.

(3) Given a sufficiently high pressure in the annular space 20, hydraulic fluid is moved into the high-pressure reservoir 16 via the feed line 15, while the return line 10 together with the bypass 12 is closed to the hydraulic fluid coming from the annular space 20 by means of the closing valves 11 and the valve 9 which is always closed during normal operation.

(4) In order to activate the hydraulic cylinders 5 and 7, the hydraulic fluid is retrieved from the high-pressure reservoir 16 and channelled in a desired way to the cylinder space of the hydraulic cylinder 5 and/or 7 via the two correspondingly switched two-way valves 21 and 22. It should be noted at this juncture that the two-way valves 21 and 22 connect the cylinder space of the hydraulic cylinder 7 to the return line 10 in the inactivated resting state, i.e. including when the control electronics or actuator have failed or are broken.

(5) As soon as hydraulic fluid is to be discharged from the cylinder spaces of the hydraulic cylinders 5 or 7, it is channelled into the return line 10 via the correspondingly switched two-way valves 21 and 22 and into the annular space 20 via the closing valves 11 which open in this direction, wherein the bypass 12 is in turn closed by the valve 9. The same applies to the feed line 15 which comprises a closing valve (not indicated) which closes in the direction of the annular space 20.

(6) If the control electronics or actuator for the control device 8 and its valves 9, 21, 22 fail, said valves assume their inactivated resting position, wherein the valves 21 and 22 connect the cylinder space of the hydraulic cylinder 7 to the return line 10, and the valve 9 opens the bypass 12. If, at the time of the damage, the moving cylinder part 19 is coupled to one of the telescopic sections 1 and 2 via the hydraulic cylinder 7 and is also in a position in which access to the control device 8 situated on the moving cylinder part 19 is not possible, the cylinder space of the hydraulic cylinder 7 can be pressurised and the cylinder lock released by pressurising the annular space 20 which is hydraulically connected to the hydraulic cylinder 7 when the valves 9, 21 and 22 are in the “emergency operating mode” position shown in FIG. 1. The valves 21 and 22 close the hydraulic fluid's path from the annular space 20 to the hydraulic cylinder 7 via the feed line 15. The same applies to the strand of the return line 10 which is closed by means of the closing valves 11. The bypass 12, by contrast, is opened by the valve 9 which is in its resting position. In order to activate the hydraulic cylinder 7, it is merely necessary to apply a sufficiently high pressure, such that the pressure sequence valve 13 opens. At a lower pressure, the bypass 12 is also closed by the pressure sequence valve 13. In this case, only the telescoping cylinder 6 is retracted, whereas the hydraulic cylinder 7 of the cylinder lock is not activated.

(7) In the scenario shown, the cylinder lock and thus the coupling between the moving cylinder part 19 of the telescoping cylinder 6 and one of the telescopic sections 1, 2 is released by pressurising the annular space 20, whereupon the telescoping cylinder 6 is retracted to an inspection or repair position.