Crane

Abstract

A tower crane, and in particular a hammerhead crane, having at least one crane operator elevator, wherein the at least one crane operator elevator is arranged inside the rectangular cross section of the crane tower.

Claims

1. A tower crane comprising a crane tower, at least one crane cab, at least one crane operator elevator, and at least one crane ladder, wherein the at least one crane operator elevator comprises an elevator car configured to travel in a vertical direction inside a rectangular cross section of the crane tower, wherein access to the at least one crane ladder and the at least one crane operator elevator is secured by an access control system comprising a controller that controls the operation of the at least one crane operator elevator, wherein the at least one crane ladder is secured by one or more access doors including an access door at a lower entrance to the at least one crane ladder, wherein the controller deactivates a power supply of the at least one crane operator elevator as soon as access to the at least one crane ladder via the one or more access doors is enabled, wherein the controller activates the power supply as soon as access to the at least one crane ladder via the one or more access doors is blocked, and wherein access to the at least one crane operator elevator is not blocked by the one or more access doors when the one or more access doors are closed.

2. The tower crane according to claim 1, wherein one or more guide rails for guiding the at least one crane operator elevator is arranged inside the rectangular cross section of the crane tower in a vertical direction from a base of the crane tower to the at least one crane cab, wherein the tower crane comprises a stationary tower.

3. The tower crane according to claim 2, wherein an elevator car guide on a side of the at least one crane operator elevator and the one or more guide rails engage with one another to compensate for play due to variances and unevenness of the one or more guide rails.

4. The tower crane according to claim 1, wherein access to the one or more access doors is enabled or blocked via a mechanical and/or electronic key.

5. The tower crane according to claim 1, wherein the access control system has one or a plurality of reader units for wireless reception of electronic key data, including data based on an RFID system, an LWID system, or a radio transmission system, wherein reception is provided over an entire length of the at least one crane ladder.

6. The tower crane according to claim 5, wherein the access control system assures selective access to the at least one crane operator elevator or to the at least one crane ladder.

7. The tower crane of claim 1, wherein the one or more access doors include an access door at an upper entrance to the at least one crane ladder.

8. The tower crane of claim 1, wherein the one or more access doors are automatically unlocked or opened as long as the access control system approves access of an authorized person to the at least one crane ladder.

9. The tower crane of claim 5, wherein the access control system comprises a plurality of reader units.

10. The tower crane of claim 9, wherein distribution of the reader units on the crane tower enables continuous reception of the electronic key data over a length of the crane tower, and wherein a path of motion of a person can thereby be determined and evaluated in the access control system.

11. The tower crane of claim 10, wherein only after the person leaves a secured region can power be restored to the at least one crane operator elevator.

12. The tower crane of claim 1, wherein a lower entry to the at least one crane operator elevator is arranged at a lowermost tower section of the tower crane, and wherein an upper entry to the at least one crane operator elevator is arranged at the at least one crane cab.

13. The tower crane of claim 1, wherein the access door at the lower entrance to the at least one crane ladder is arranged in a vertical direction above a lower entry to the at least one crane operator elevator.

14. The tower crane of claim 1, wherein the access door at the lower entrance to the at least one crane ladder is arranged at a lowest entry region to the at least one crane ladder in a vicinity of a base of the crane tower.

15. The tower crane of claim 7, wherein the upper entrance to the at least one crane ladder is at a top of the crane tower.

16. The tower crane of claim 1, further comprising, in addition to the one or more access doors which secure the at least one crane ladder, an access door for entering the elevator car.

17. The tower crane of claim 16, wherein the access door for entering the elevator car is a side door and is configured to slide inwardly into the elevator car.

18. The tower crane of claim 1, wherein the space requirement for the at least one crane ladder requires approximately two thirds of the rectangular cross section of the crane tower, and wherein the at least one crane operator elevator is located in the remaining rectangular cross section of the crane tower.

19. The tower crane of claim 18, wherein a shaft of the at least one crane operator elevator occupies approximately half of the remaining rectangular cross section of the crane tower.

Description

(1) Additional advantages and features of the invention will be explained with the aid of the embodiments shown in greater detail in the drawings. The drawings show:

(2) FIG. 1A shows a cross section view through the tower of the tower crane according to the invention, FIG. 1B shows a detailed view of the lower entry point to the crane ladder, and FIG. 1C schematically shows an access control system and crane controller.

(3) FIG. 2 shows a schematic side view of the tower crane according to the invention.

(4) FIG. 3 shows a detailed view of the crane ladder and crane operator elevator.

(5) FIG. 1 shows a cross section through a single tower section 10 of the hammerhead crane according to the invention. The entire hammerhead crane has a conventional tower ladder 20, which consists of individual ladder elements 21. The crane operator can thus enter into the hollow space of the lowest tower section and reach the crane cab 40 (FIG. 2) by means of the ladder arrangement 21. The space requirement for the crane ladder requires approximately two thirds of the rectangular cross section of the crane tower. The arrow 22 indicates the stairway path through tower section 10.

(6) According to the invention, a crane operator elevator 30 is located in the remaining cross sectional area, which complements the conventional crane ladder (20). The elevator shaft is located in the plane of the drawing to the right and under the depicted corner of the tower section, and occupies approximately half of the remaining cross sectional area.

(7) The car 31 of the crane operator elevator 30 slides from the base of the tower 50 up to the crane cab 40 in the vertical direction (FIGS. 2 and 3). Two guide rails 60 are provided as guiding means, which pass inside the tower sections parallel to one another in the vertical direction from the base of the tower 50 to the crane cab 40. The car 31 itself is at least partially closed. A mechanical door mechanism 32 is used to enter the cabin. In order to open the access door 32, it is slid inwardly into the car 31 in the direction of arrow 33. Other opening mechanisms are obviously possible, and are included within the scope of the invention.

(8) A cable drive is used to drive the crane operator elevator 30, which is designed in a well known manner and form. The capstan 70 is provided (FIG. 3) in the region of the top of the tower, such that the elevator cable 71 passes from the elevator car 31 to the top of the tower, and is wound onto or about the capstan 70. Alternatively, the capstan can be arranged on the roof of the elevator car in a manner and form not shown here.

(9) Since the guide rails 60 remain fixed to the individual tower sections 10 during transport of the crane, it is necessary that they be subdivided into individual guide rail segments. Individual elements are thus mounted on the inside of each assembled tower section.

(10) Due to certain fabrication tolerances of the tower sections, a misalignment between the neighboring guide elements of the guide rails 60 may occur while rigging the individual tower sections. In order to eliminate time consuming readjustments, a certain amount of play is allowed in the guide rails 60 during engagement of the guide means of the car 31. In combination with the cable drive, it is possible to pass over such misalignments between neighboring guide elements without difficulty.

(11) An access control system 91 is installed for safety reasons in order to avoid the hazard to personnel in the crane ladder 20 region caused by the elevator car 31. A crane controller 92 is connected to the control system. The access control system has one or a plurality of reader units 93 for wireless reception of electronic key data, including data based on an RFID system 94, an LWID system 95, or a radio transmission system 96, wherein reception is provided over an entire length of the at least one crane ladder.

(12) As can be seen in FIG. 1a, access to the crane ladder 20 can be opened or blocked by a door assembly 80. The mechanical closing motion of the door 80 can be accomplished either automatically or manually. A door control mechanism is claimed for locking and unlocking the door 80 electronically through the access control system.

(13) The door 80 that is shown is arranged in the entrance region to the crane ladder 20 in the vicinity of the base of the crane. Another door element 80 is also located at the top of the tower, which blocks or enables access to the crane ladder.

(14) However, it must be assured that the access 90, 100 to the crane elevator 30 is not blocked by the door 80. In the indicated exemplary embodiment, the door 80 is arranged in the vertical direction above the entrance 90 to the elevator system 30. The crane operator is allowed access to the crane ladder 20 with the aid of a mechanical and/or electronic access key 85. If the door 80 is opened, the crane control system then automatically blocks the power to the elevator system 30 so that elevator operation is prevented when the crane ladder 20 is unblocked.

(15) After the door 80 is closed, it must then be locked with the key, after which permission to vacate is granted through a key switch. As soon as all required steps have been carried out according to specifications, the operation of the elevator 30 is again enabled. The same is true for access to the crane ladder 20 at the top, in which the upper access 100 is freely accessible to the elevator car 31, but access to the stairs descending the tower 20 is blocked and can be opened only by means of keys.

(16) In case of emergency, a key can be located in a glass box at both doors 80.

(17) Furthermore, access 90, 100 to the elevator 30 can likewise be secured by a key.

(18) Alternatively or in addition, one or more RFID chip reader units can be installed in each door 80. Persons who wish to enter the secured region of the crane ladder 20, whether gaining access from the top or bottom, must have an RFID chip that displays the appropriate dates for access from the access control system. Upon entry of the person having the RFID chip in the receiver region of the reader units, the electronic key data can be read by the chips and access is granted for the doors 80. The same is true for access 90, 100 to the cabin, which can likewise be controlled by means of reader units.

(19) In this case as well, the power to the crane operator elevator 30 can be interrupted as soon as one of the doors 80 is opened or unlocked. The actual passage through the door 80 by the person is simultaneously detected by the electronic access control system due to the movement of the chip. For this reason a plurality of reader units are distributed over the entire crane tower in order to enable continuous reception over the length of the tower. This authorized region is designated by the arrow 110. The path of motion of the chip, or the person, can thereby be determined and evaluated in the crane control system. Only after the person having the RFID chip leaves the secured region 110 can the door 80 at the bottom or at the top again be locked and the power restored to the crane operator elevator 30.