GB1568332A - Transport arrangement preferably for heavy loads - Google Patents

Description

(54) TRANSPORT ARRANGEMENT, PREFERABLY FOR HEAVY LOADS (71) We, TOTAL TRANSPORTATION SYSTEMS (International) A/S, a Norwegian company, of Bjrnegården, 5200 Os, Norway, do hereby dedare 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: The invention relates to a transport arrangement, preferably for heavy loads such as, for instance, relatively large ship sections in shipyards or lighters on board socalled "lash" ships.

According to the present invention, there is provided a transport arrangement, preferably for heavy loads, comprising a number of trolleys which can be moved adjacent supporting means for loads by means of a flexible pulling member which extends over wheels, at least one of which can be driven in rotation, the trolleys comprising at least one main trolley having a hydraulic pump arrangement coupled to the flexible pulling member and a number of load-bearing trolleys having hydraulic lifting members hydraulically coupled to the pump arrangement, wherein the flexible pulling member is endless and extends around a drive wheel coupled so as to drive the pump arrangement when rotated; the main trolley has a releasable brake arrangement for braking the drive wheel to enable the trolleys to be pulled by the flexible pulling member and a releasable brake arrangement for braking the main trolley to enable the lifting members to operate; and the main trolley has means which cause the brake arrangement of the drive wheel to be released when the brake arrangement of the main trolley is actuated, and vice versa.

Norwegian Patent Specification No.

-136 453 discloses a transport arrangement comprising a number of trolleys which can be moved between supporting members for loads by means of a flexible pulling member which extends over wheels, at least one of which can be driven in rotation. The trolleys comprise at least one main trolley having a hydraulic pump arrangement connected to the flexible pulling member and a number of load-bearing trolleys having hydraulic lifting members hydraulically connected to the pump arrangement. The pump arrangement mainly comprises a cylinder having a piston disposed slidably therein. The piston and cylinder are indirectly connected to each end of the flexible pulling member. The driving force is transmitted to the pump arrangement by the alternate tightening and slackening of the pulling member, the piston performing a horizontally reciprocating pumping movement in the cylinder.The force-transmitting tightening movement of the pulling member is achieved by one or more of the wheels of the pulling member being moved via the agency of a hydraulic actuator.

One disadvantage of the prior art transport arrangement is that the pump arrangement on the main trolley must be specially constructed and is therefore disproportionately expensive. Another factor which increases costs is the hydraulic actuator used for moving the wheel, and last but not least the individual hydraulic system which the actuator requires.

Another disadvantage is that the pump arrangement is of the reciprocating kind; so that hydraulic pressure medium is sup plied intermittently to the lifting cylinders of the load-bearing trolleys. As a result the load is lifted jerkily, with consequent extra stressing.

For a better understanding of the invention, embodiments thereof will now be described in greater detail, by way of example, with reference to the drawings, in which: Figs. 1 and 1A show a transport arrangement according to the invention in which the main trolley is manually controlled; and Figs. 2 and 2A show a variant of the transport arrangement illustrated in Fig. 1, the main trolley being automatically controlled.

Referring to Figs. l and 1 A, a transport arrangement runs on rails 1 and mainly comprises a main trolley 2 connected to lifting trolleys 3 which can move on whee's along the rails via the agency of a flexible pulling member 4 extending over wheels 5, 6 which are drivably connected to motors 7 and 8 respectively. The pulling member 4 is endless and in the main trolley 2 extends over two rigidly mounted wheels 9, 10 and a rigidly mounted drive wheel 11 disposed therebetween.Drive wheel 11 has a brake drum 12 which can be held by a brake shoe 13 operated by hydraulic brake cylinders 14. Via a chain transmission 15 or the like the drive wheel 11 is connected to a hydraulic pump 16 of rotary type which can pump hydraulic medium in both directions, in dependence on the direction of rotation.

The main trolley also has a rail brake 17 shown in greater detail in Fig. 1A, in which it is viewed in the longitudinal direction of the rail. The rail brake 17 mainly comprises two arms 18 which adjacent their centres are pivotably connected to one another and can be moved pincer-fashion by a hydraulic cylinder 19 disposed between the upper ends of the arms. The lower ends of the arms engage around the rail 1 and, when pressure medium is supplied to the cylinder - 19, grip the rail 1 tightly and therefore prevent the main trolley from moving. Pressure medium is supplied to the cylinder 19 and brake cylinders 14 from the pump 16 via a manual control valve 20.

The control valve has two positions, a first position in which the pressure medium is supplied to the brake cylinders 14 to actuate the brake shoes 13, but not to the rail brake 17, and a second position in which the pressure medium is supplied to the rail brake for its actuation, and also to the brake cylinders- 14 to disengage the brake shoes 13 from the brake- drum 12.

The lifting trolleys 3 comprises -hydraulic lifting members, in this embodiment taking the form of a cylinder 21 with associated piston 22. The two sides of the piston are each hydraulically connected to a side of the pump 16. The rotation of the pump in one direction therefore raises the piston 29, while its rotation in the opposite d;rec- tion lowers the piston. The pressure side i.e. the underside of the pistons 22is hydraulically connected to an accumulator 23 which evens out any pressure pulses, makes up for any leakages on the pressure side, and in certain situations supplies pressure medium to the rail brake 17.

When the transport arrangement is to be used to move a load, first the trolleys are moved under the load, which rests on loadsupporting members 25, with the lifting pistons lowered. The control valve 20 is in the opposite position from that shown in Fig. 1, so that the pressure medium is supplied to the brake cylinders 14 to actuate the trade shoes 13. As a result the drive wheel 11 is locked, as a result of which the flexible pulling member 4 is locked in relation to the main trolley 2, so that the main trolley and lifting trolleys can be driven over the rails in the required direction by one of the motors 7 or 8.

When the trolleys are brought into position under the load 24, the control valve is moved manually into the position shown in Fig. 1. As a result the drive wheel brakes 13, 14 are released, and the rail brake 17 is applied by means of pressure medium from the accumulator 23. Then the drive motor 7 is started, so that the pulling member 4 is set in movement. in the meantime the rail brake 17 prevents the main trolley 2 from moving, so that the movement of the pulling member 4 drives the drive wheel Il, which drives the pump 16 in the direction indicated by arrow A. As a result pressure medium is supplied to the underside of the lifting pistons, so that the pistons are moved upwards and lift the load 22 upwards from the load-supporting members 25.

When the load 24 is lifted high enough, the control valve 20 is changed over into the opposite position from that illustrated in Fig. 1. The pressure from the lifting cylinders and the accumulator is supplied to the brake cylinders 14 to actuate the brake shoes 13. At the same time the rail brake 17 is released. The pulling member 4 is then again locked in relation to the main trolley 2, and one of the motors 7, 8 can drive the load over the rails 1.

When the load has reached the required place, the drive motor used is stopped.

Then the control valve 20 is changed over, so that the rail brake is applied and the drive wheel brake released. Thereafter the drive motor 8 is so operated that the pump 16 is driven in the direction indicated by arrow B, so that the load 24 is lowered.

When the load has reached the required place and the lifting pistons 22 have been brought into the bottom position, the control valve 20 can again be changed over to apply the drive wheel brake and release the rail brake, whereafter the trolleys can be driven out from under the load and the aforementioned operations repeated.

The embodiment of the transport arrangement according to the invention illustrated in Figs. 2 and 2A differs from that illustrated in Fig. 1 mainly by virtue of the feature that the control valve is changed over automatically, not manually. This requires minor modifications to some of the members illustrated in Fig. 1, which in Fig. 2 have like reference numerals with the addition of an apostrophe.

The main trolley's 2 wheels 9', 10' for the pulling member 4 are in this embodiment movably attached to the main trolley. The wheels are each attached to one end of a respective rocking arm 26 which is pivo tably attached to the main trolley 2. Disposed between the other ends of the rocker arms is a pump cylinder 27 which is hydraulically connected to a shift device on the control valve 20'. Disposed between the wheels 9', 10' is a tension spring 28 which tends to move the wheels towards one another against the tensioning effect of the pulling member 4.

As well as the hydraulic shift device for the control valve 20', the hydraulic system comprises other components whose function is indicated by symbols which are familiar to a person skilled in the art and will therefore not be described in detail here.

When the transport arrangement illustrated in Fig. 2 is to be used for transporting a heavy load 24, first the trolleys 2 and 3 are driven in under the load with lowered lifting pistons 22. The control valve 20' is then in the position shown in the drawing. When the trolleys have moved into place, the two drive motors 7, 8 are started to tension the pulling member 4.

The wheels 9', 10' are moved away frcm one another against the force of the spring 28, and the pump cylinder 27 pressurises the shift device 29 on the control valve 20', so that it shifts. Pressure is supplied from the accumulator 23 to the rail brake 17, while the drive wheel brake 13, 14 is released. Continuing to allow the drive motor 7 to operate supplies pressure medium to the underside of the lifting pistons 22, so that the load 24 is lifted. When the load is sufficiently lifted, the drive motor 8 is started again, so that the pulling member 4 is tightened and moves the wheels 9', 10' away from one another. Pressure is again supplied from the pump cylinder 27 to the shift device 29, so that the control valve 20' changes over, and the pump brake (i.e. the drive wheel brake) is applied, while the rail brake is released.The load is thus driven to the required place by means of one of the drive motors 7, 8. The two drive motors are then used to tension the pulling member again, so that the control valve 20' changes over to apply the rail brake and release the pump brake. Then the drive motor 8 is used to drive the pump 16, so that the lifting pistons 22 and the load 24 are lowered. With the lifting pistons in the lower position that pulling member is again tensioned by means of the drive motors 7, 8, the rail brake being released, and the pump brake applied, so that the transport arrangement is ready to repeat the aforementioned operations.

It will be clear to a person skilled in the art that the system for the automatic changing over of the control valve can be modified in a number of ways. For instance, the wheels 9', 10' need not be suspended on rocker arms and act via the agency of the rocker arms on the pump cylinder 27, but can be directly attached to the pump cylinder, for instance, by its taking the place of the spring 28. The pump cylinder can also be adapted to perform the function of the spring, for instance by one side of the piston being acted upon by a pressurised gas, while the other side of the piston is connected to the shift device 29. The pump cylinder can also be connected to only one of the wheels, while the other is rigidly mounted on the trolley 2.

WHAT WE CLAIM IS; 1. A transport arrangement, preferably for heavy loads, comprising a number of trolleys which can be moved adjacent supporting means for loads by means of a flexible pulling member which extends over wheels, at least one of which can be driven in rotation, the trolleys comprising at least one main trolley having a hydraulic pump arrangement coupled to the flexible pulling member and a number of load-bearing trolleys having hydraulic lifting members hydraulically coupled to the pump arrangement, wherein the flexible pulling member is endless and extends around a drive wheel coupled so as to drive the pump arrangement when rotated: the main trolley has a releasable brake arrangement for braking the drive wheel to enable the trolleys to be pulled by the flexible pulling member and a releasable brake arrangement for braking the main trolley to enable the lifting members to operate; and the main trolley has means which cause the brake arrangement of the drive wheel to be released when the brake arrangement of the main trolley is actuated, and vice versa.

2. A transport arrangement according to claim 1, wherein the brake arrangement of the drive wheel and the brake arrangement of the main trolley each has at least one hydraulic actuating cylinder hydraulically coupled to a control device which ensures that pressure is supplied to at least one actuating cylinder of the drive wheel brake arrangement and that at the same time pressure is relieved in at least one actuating cylinder of the main trolley brake arrangement, and vice versa.

3. A transport arrangement according to claim 2, wherein the said means comprise at least one wheel which is movably disposed on the main trolley and engages the flexible pulling member and which, when the pulling member is tensioned, is moved against the force of a resilient member and causes a shifting of the control device such that the brake arrangement of the main trolley is actuated at the same time as the brake arrangement of the drive wheel is released, or vice versa.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. tably attached to the main trolley 2. Disposed between the other ends of the rocker arms is a pump cylinder 27 which is hydraulically connected to a shift device on the control valve 20'. Disposed between the wheels 9', 10' is a tension spring 28 which tends to move the wheels towards one another against the tensioning effect of the pulling member 4. As well as the hydraulic shift device for the control valve 20', the hydraulic system comprises other components whose function is indicated by symbols which are familiar to a person skilled in the art and will therefore not be described in detail here. When the transport arrangement illustrated in Fig. 2 is to be used for transporting a heavy load 24, first the trolleys 2 and 3 are driven in under the load with lowered lifting pistons 22. The control valve 20' is then in the position shown in the drawing. When the trolleys have moved into place, the two drive motors 7, 8 are started to tension the pulling member 4. The wheels 9', 10' are moved away frcm one another against the force of the spring 28, and the pump cylinder 27 pressurises the shift device 29 on the control valve 20', so that it shifts. Pressure is supplied from the accumulator 23 to the rail brake 17, while the drive wheel brake 13, 14 is released. Continuing to allow the drive motor 7 to operate supplies pressure medium to the underside of the lifting pistons 22, so that the load 24 is lifted. When the load is sufficiently lifted, the drive motor 8 is started again, so that the pulling member 4 is tightened and moves the wheels 9', 10' away from one another. Pressure is again supplied from the pump cylinder 27 to the shift device 29, so that the control valve 20' changes over, and the pump brake (i.e. the drive wheel brake) is applied, while the rail brake is released.The load is thus driven to the required place by means of one of the drive motors 7, 8. The two drive motors are then used to tension the pulling member again, so that the control valve 20' changes over to apply the rail brake and release the pump brake. Then the drive motor 8 is used to drive the pump 16, so that the lifting pistons 22 and the load 24 are lowered. With the lifting pistons in the lower position that pulling member is again tensioned by means of the drive motors 7, 8, the rail brake being released, and the pump brake applied, so that the transport arrangement is ready to repeat the aforementioned operations. It will be clear to a person skilled in the art that the system for the automatic changing over of the control valve can be modified in a number of ways. For instance, the wheels 9', 10' need not be suspended on rocker arms and act via the agency of the rocker arms on the pump cylinder 27, but can be directly attached to the pump cylinder, for instance, by its taking the place of the spring 28. The pump cylinder can also be adapted to perform the function of the spring, for instance by one side of the piston being acted upon by a pressurised gas, while the other side of the piston is connected to the shift device 29. The pump cylinder can also be connected to only one of the wheels, while the other is rigidly mounted on the trolley 2. WHAT WE CLAIM IS;

1. A transport arrangement, preferably for heavy loads, comprising a number of trolleys which can be moved adjacent supporting means for loads by means of a flexible pulling member which extends over wheels, at least one of which can be driven in rotation, the trolleys comprising at least one main trolley having a hydraulic pump arrangement coupled to the flexible pulling member and a number of load-bearing trolleys having hydraulic lifting members hydraulically coupled to the pump arrangement, wherein the flexible pulling member is endless and extends around a drive wheel coupled so as to drive the pump arrangement when rotated: the main trolley has a releasable brake arrangement for braking the drive wheel to enable the trolleys to be pulled by the flexible pulling member and a releasable brake arrangement for braking the main trolley to enable the lifting members to operate; and the main trolley has means which cause the brake arrangement of the drive wheel to be released when the brake arrangement of the main trolley is actuated, and vice versa.

2. A transport arrangement according to claim 1, wherein the brake arrangement of the drive wheel and the brake arrangement of the main trolley each has at least one hydraulic actuating cylinder hydraulically coupled to a control device which ensures that pressure is supplied to at least one actuating cylinder of the drive wheel brake arrangement and that at the same time pressure is relieved in at least one actuating cylinder of the main trolley brake arrangement, and vice versa.

3. A transport arrangement according to claim 2, wherein the said means comprise at least one wheel which is movably disposed on the main trolley and engages the flexible pulling member and which, when the pulling member is tensioned, is moved against the force of a resilient member and causes a shifting of the control device such that the brake arrangement of the main trolley is actuated at the same time as the brake arrangement of the drive wheel is released, or vice versa.

4. A transport arrangement according

to claim 3, wherein the or each movable wheel is connected to a hydraulic pump cylinder hydraulically connected to a shift device on the control device which is in the form of a valve.

5. A transport arrangement according to claims 3 or 4, characterised in that it comprises two drive motors adapted simultaneously to drive the pulling member in each direction to produce the aforementioned tensioning.

6. A transport arrangement substantially as hereinbefore described with reference to and as shown in Fig. 1 or Fig. 2 of the accompanying drawings.