GB1573157A - Mechanism for moving the operating cage of a motor-driven turntable firemen's ladder from a transporting position to an operating position - Google Patents

Description

(54) A MECHANISM FOR MOVING THE OPERATING CAGE OF A MOTOR-DRIVEN TURNTABLE FIREMEN'S LADDER FROM A TRANSPORTING POSITION TO AN OPERATING POSITION (71) We, MAGIRUS-DEUTZ AKTIENGESELLSCHAFT, a German Body Corporate, of Schillerstrasse 2, 79 Ulm, German Federal Republic, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: This invention relates to a mechanism for moving the operating cage or basket of a motor-driven turntable firemen's ladder between a transporting position and an operating position at approximately 90" thereto, comprising a guide system for the cage including two hydraulic cylinders interconnected by hydraulic lines, one cylinder being a receiving cylinder disposed at the cage and the other being a transmitting cylinder disposed between the turntable and the lower part of the ladder, the transmitting cylinder being energized from a hydraulic pressure-medium circuit of hydraulic supporting columns for supporting the vehicle during operation of the ladder, a control lever for raising and lowering the columns acting also to move the cage from the transporting to the operating position while the columns are being lowered and to move the cage back to the transporting position while the columns are being raised, the transmitting cylinder being isolated from the said pressure-medium circuit during operation of the ladder and the transmitting and receiving cylinders being coupled together.

It is known for the operating cage or basket of a motor-driven turntable ladder to be pivoted when required by the guide system mto a position (the transporting position) which is swung forwards and downwards by approximately 90" relative to the operating position. A disadvantage of the known system is that the cage has to be moved into the transporting position by the turntable ladder operator. There is thus a risk that this movement may be accidentally initiated during a rescue operation.

It is also known for an operating cage or basket disposed on the top end of an extensible mast to be controlled by a hydraulic cylinder pivoting between the cage and the end of the mast and connected by hydraulic lines to a second hydraulic cylinder pivoted between the bottom of the mast and the vehicle, so that the bottom of the cage is always kept horizontal, independently of the angle of inclination of the extended mast. However, in the case of the last-mentioned guide system, the cage cannot be pivoted into a transporting position.

Starting from this prior art, the aim of the present invention is to provide a mechanism of the above-mentioned kind wherein the cage is moved into the operating or transporting position at the same time as hydraulic columns for supporting the vehicle during operation of the ladder are raised or lowered.

To this end, according to the invention, there is provided a mechanism for moving the operating cage or basket of a motordriven turntable firemen's ladder between a transporting position and an operating position approximately 90" thereto, comprising a guide system for the cage including two hydraulic cylinders interconnected by hydraulic lines, one cylinder being a receiving cylinder disposed at the cage and the other being a transmitting cylinder disposed between the turntable and the lower part of the ladder, the transmitting cylinder being energized from a hydraulic pressure-medium circuit of hydraulic supporting columns for supporting the vehicle during operation of the ladder, a control lever for raising and lowering the columns acting also to move the cage from the transporting to the operating position while the columns are being lowered and to move the cage back to the transporting position while the columns are being raised, the transmitting cylinder being isolated from the said pressure-medium circuit during operation of the ladder and the transmitting and receiving cylinders being so coupled as to guide the cage while the ladder is being raised and lowered so that the bottom of the cage is always parallel to the longitudinal axis of the vehicle.

The advantage of the inventive improvement on the mechanisms earlier is that the additional pivoting motion of the cage occurs automatically, without the intervention of the operator, in conjunction with the switching operations required for operating the supporting columns. As a result of this advantageous construction of the mechanism, the operator is relieved of any extra work and the risk of mistakes is eliminated.

Another advantage of the mechanism according to the invention is that the construction is very simple and compact, since the hydraulic drive to the cage is connected to the hydraulic pressure-medium circuit of the columns supporting the vehicle.

According to one embodiment, the pressure-medium circuit comprises a pressure-medium pump driven by a pressure-medium motor connected via hydraulic supply lines to the main pump for the columns.

Advantageously, in order to simplify the control of the pressure-medium motor, a multi-position two-way slide valve having a flow-through position and a closed position is disposed in the hydraulic supply lines and actuated by an electro-magnetic actuator via switching contacts in operative connection with the control lever for the columns.

According to another advantageous feature, in order further to simplify the erection drive, an additional multi-position slide valve is disposed in the hydraulic connecting lines from the pressure-medium pump to the guide system, and further electro-magnetic actuators for the additional slide valve controlled by the said contacts operated by the control lever.

An embodiment of the invention is shown in the accompanying drawing, which shows a part-diagrammatic, part-schematic layout of a mechanism according to the invention.

Referring to the drawing, a turntable mounting 2 on a vehicle 1 is rotatable around a vertical axis, and a turntable ladder 4 is connected to mounting 2 so as to be pivotable around a horizontal erecting shaft 3.

Ladder 4 comprises a number of telescopically extensible parts, and a rescue or operating cage or basket 5, pivotable around a horizontal axis, is secured to the outer end of that part of the ladder which can be furthest extended. Cage 5 is controlled by a hydraulic guide system 6, so that the cage bottom remains horizontal irrespective of the angle to which ladder 4 is raised.

The guide system 6 comprises a transmitter cylinder 7 pivoted between mounting 2 and the bottom end of ladder 4, or the erecting frame on which the ladder is mounted, and a receiving cylinder 8 pivoted to cage 5 and the top end of the ladder. Cylinders 7, 8 are so connected by hydraulic lines 9, 10 that the same amount of liquid always flows between cylinders 7 and 8 when ladder 4 moves.

In the drawing, ladder 4 is shown in the operating and in the transporting position.

For the purpose of transportation, cage 5 can be brought into a position in which its bottom is out of sight of the driver and thus does not restrict visibility. To this end, cage 5 is moved from its operating position, corresponding to the horizontal guided position, through approximately 90C by the receiver cylinder 8 of guide system 6, so that the front wall of cage 5 is in line with ladder 4 when retracted.

According to the invention, this additional pivoting motion of the cage is initiated at the same time as the switching-on or off the columns 11, 12 for supporting ladder 4 on the vehicle. To this end, the transmitting cylinder 7 is connected by lines 13, 14 to hydraulic drive 15. Drive 15 comprises a pressuremedium pump 16 and a pressure-medium motor 17 connected by supply lines 18, 19 to the hydraulic system for columns 11, 12 and the associated main lines 20, 21 and main pump 22. A multi-position slide valve 23, having a closed and a through-flow position, is disposed in connecting lines 13, 14 and a similar multi-position slide valve 24 is disposed in supply lines 18, 19. When the ladder is in operation, valves 23, 24 are in the closed position, so that the guide system 6 is completely disconnected and isolated from the hydraulic system of the columns.This position is also secured by a pressure-controlled shut-off valve 35 in lines 13, 14. Valves 23, 24 are moved into the other positions directly by the control lever 25 of columns 11, 12. Lever 25 is coupled to a multi-way valve 26 installed in the main hydraulic lines 20, 21. Lever 25 actuates two switching contacts 28, 29 via a switching arm 27. The two contacts 28, 29 are connected via electric circuits 30, 31 to an electro-magnetic actuator 32 operatively connected to the multi-position slide valve 24 and to electromagnetic actuators 33, 34 at slide valve 23.

If ladder 4 is in the standby position after use, lever 25 is moved clockwise to retract columns 11, 12, so that arm 27 touches contact 29. A current flows through line 31 to the electro-magnetic actuators 32, 33, and the two valves 23, 24 are moved to the left in the drawing. As a result, pump 22 delivers pressure oil along line 18 to motor 17. Motor 17 drives pump 16, which conveys pressure medium from an oil storage container through line 14 and cylinder 7 to cylinder 8, which moves cage 5 from the operating into the transporting position.

Conversely, when lever 25 extends the columns 11 and 12, arm 27 touches contact 28. Current flows along line 3 to electromagnetic actuators 32 and 34. Slide valve 23 is pushed to the right and valve 24 is in the flow-through position, so that pump 16 delivers pressure medium through line 13 directly to cylinder 8, which moves cage 5 from the transporting to the operating position. As soon as cage 5 has reached the operating position, a limit switch moves one of the valves 23 or 24 into the closed position, so that the parallel guide system 6 is disconnected from the hydraulic system of columns 11, 12.

WHAT WE CLAIM IS: 1. A mechanism for moving the operating cage or basket of a motor-driven turntable firemen's ladder between a transporting position and an operating position at approximately 90C thereto, comprising a guide system for the cage including two hydraulic cylinders interconnected by hydraulic lines, one cylinder being a receiving cylinder disposed at the cage and the other being a transmitting cylinder disposed between the turntable and the lower part of the ladder, the transmitting cylinder being energized from a hydraulic pressure-medium circuit of hydraulic supporting columns for supporting the vehicle during operation of the ladder, a control lever for raising and lowering the columns acting also to move the cage from the transporting to the operating position while the columns are being lowered and to move the cage back to the transporting position while the columns are being raised, the transmitting cylinder being isolated from the said pressure-medium circuit during operation of the ladder and the transmitting and receiving cylinders being so coupled as to guide the cage while the ladder is being raised and lowered so that the bottom of the cage is always parallel to the longitudinal axis of the vehicle.

2.A mechanism according to Claim 1, in which the pressure-medium circuit comprises a pressure-medium pump driven by a pressure-medium motor connected by hydraulic supply lines to a main pump for the supporting columns.

3. A mechanism according to Claim 2, comprising a multi-position slide valve having a flow-through position and a closed position disposed in the said hydraulic supply lines, and an electro-magnetic actuator to actuate the slide valve, the actuator being controlled by contacts operated by the control lever.

4. A mechanism according to Claim 3, comprising an additional multi-position slide valve disposed in hydraulic lines connecting the pressure-medium pump to the guide system, and further electro-magnetic actuators for the additional slide valve controlled by the said contacts operated by the control lever.

5. A mechanism for moving the operating cage or basket of a motor-driven turntable firemen's ladder from a transporting position into an operating position at approximately 90" thereto, constructed and arranged substantially as herein described, with reference to and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. Conversely, when lever 25 extends the columns 11 and 12, arm 27 touches contact 28. Current flows along line 3 to electromagnetic actuators 32 and 34. Slide valve 23 is pushed to the right and valve 24 is in the flow-through position, so that pump 16 delivers pressure medium through line 13 directly to cylinder 8, which moves cage 5 from the transporting to the operating position. As soon as cage 5 has reached the operating position, a limit switch moves one of the valves 23 or 24 into the closed position, so that the parallel guide system 6 is disconnected from the hydraulic system of columns 11, 12. WHAT WE CLAIM IS:

1. A mechanism for moving the operating cage or basket of a motor-driven turntable firemen's ladder between a transporting position and an operating position at approximately 90C thereto, comprising a guide system for the cage including two hydraulic cylinders interconnected by hydraulic lines, one cylinder being a receiving cylinder disposed at the cage and the other being a transmitting cylinder disposed between the turntable and the lower part of the ladder, the transmitting cylinder being energized from a hydraulic pressure-medium circuit of hydraulic supporting columns for supporting the vehicle during operation of the ladder, a control lever for raising and lowering the columns acting also to move the cage from the transporting to the operating position while the columns are being lowered and to move the cage back to the transporting position while the columns are being raised, the transmitting cylinder being isolated from the said pressure-medium circuit during operation of the ladder and the transmitting and receiving cylinders being so coupled as to guide the cage while the ladder is being raised and lowered so that the bottom of the cage is always parallel to the longitudinal axis of the vehicle.

2.A mechanism according to Claim 1, in which the pressure-medium circuit comprises a pressure-medium pump driven by a pressure-medium motor connected by hydraulic supply lines to a main pump for the supporting columns.

3. A mechanism according to Claim 2, comprising a multi-position slide valve having a flow-through position and a closed position disposed in the said hydraulic supply lines, and an electro-magnetic actuator to actuate the slide valve, the actuator being controlled by contacts operated by the control lever.

4. A mechanism according to Claim 3, comprising an additional multi-position slide valve disposed in hydraulic lines connecting the pressure-medium pump to the guide system, and further electro-magnetic actuators for the additional slide valve controlled by the said contacts operated by the control lever.

5. A mechanism for moving the operating cage or basket of a motor-driven turntable firemen's ladder from a transporting position into an operating position at approximately 90" thereto, constructed and arranged substantially as herein described, with reference to and as illustrated in the accompanying drawing.