GB2354489A

GB2354489A - Work boat with hydraulically controlled boom

Info

Publication number: GB2354489A
Application number: GB9922569A
Authority: GB
Inventors: Brian Boner
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-09-23
Filing date: 1999-09-23
Publication date: 2001-03-28
Anticipated expiration: 2019-09-23
Also published as: GB2354489B; GB9922569D0

Abstract

A work boat 1 comprises a hydraulic boom assembly arranged to carry a tool 7, with user operable control means which allow location of said tool mounted on the boom assembly to be moved to a desired working position. The hull may be designed to maximise displacement and stability, with the engine, hydraulic pump and tank located below deck level to further enhance stability. The boom assembly may comprise a pair of spaced arms 5 pivotally mounted at one end to a midpoint 31 of the hull, with an implement bar 6 for supporting the tool mounted between the other ends of the arms. The work boat may be propelled by hydraulically powered means 4.

Description

2354489 Work Boats This invention relates to work boats which are suitable

for carrying out maintenance work on canals and other waterways.

Various tasks are necessary to keep canals and other waterways in a usable condition, for example weed or vegetation tends to grow within the waterway and channels through this weed must be maintained to allow the safe passage of boats. Further, in various locations along a waterway the bank may have to be reinforced and maintenance work on such reinforcements as well as their initial deployment is necessary.

Thus it is desirable if a device can be provided which can be used for a variety of different maintenance tasks many of which will have to be carried out in regions which are inaccessible from land surrounding the waterway.

It is an object of this invention to provide a device for carrying out maintenance work on canals and other waterways which alleviates some of the drawbacks associated with existing devices.

2 According to the present invention there is provided a work boat for carrying out maintenance work on canals and other waterways comprising a boom assembly arranged to carry a tool and user operable hydraulic control means for controlling the boom assembly to allow location of a tool mounted on the boom assembly in a desired working position.

The hydraulic control means typically includes a hydraulic fluid circuit comprising pumping means, a plurality of actuators for driving components and interconnecting piping. Preferably the interconnecting piping consists of rigid pipe wherever possible flexible hosing only being used across moving arcs. This reduces the risks of bursts.

The hydraulic control means may comprise remotely operable valve means. One or more user input devices, for example a joystick, may be connected to the valve means and disposed at a location remote from the hydraulic fluid circuit. Preferably the valve means is operated by one or more solenoid.

The provision of remotely operable valve means serves to minimize the length of piping used and allows the user 3 to operate the boat from a location safely away from the hydraulic circuit.

At least one hydraulically operated paddle wheel may be provided for propelling the boat. Preferably a pair of paddle wheels are provided each being disposed on a respective side of the boat. The hydraulic control means may be arranged for controlling the paddle wheel or wheels in addition to the boom assembly.

Preferably common pumping means is provided to supply the necessary hydraulic fluid to all of the hydraulically operated components. Preferably the common pumping means is a variable displacement pump. Preferably the common pumping means is controllable in response to a load sensing signal. This means that it is possible to ensure that each of the hydraulically operated components receives the required supply of fluid at all times.

Preferably the remotely operable valve means is arranged to receive hydraulic fluid from the common pumping means and control the flow of fluid to and from each hydraulically operated component.

Preferably the remotely operable valve means has load 4 sensing capabilities and is arranged to transmit a load sensing signal to the common pumping means.

Preferably the hydraulic circuit comprises one or more safety valve arranged to prevent operation of some or all of the hydraulic components in the event of predetermined conditions, for example any one or any combination of power shut down, power failure, pipe failure and hose failure.

An isolator switch may be provided which may be operable by a user and arranged to lock all user operable controls and hold all of the hydraulic components static.

The boom assembly may comprise a pair of spaced arms which may be pivotally mounted on the boat. At least one boom hydraulic ram may be provided to allow controlled movement of the arms around their mountings. The mountings for the pair of arms may be disposed towards the midpoint between the bow and stern to aid stability.

The arms may be arranged to extend from the mountings towards and preferably beyond the bow of the boat.

The boom assembly may further comprise an implement bar 25 disposed between the distal ends the spaced arms. The implement bar may be pivotally mounted relative to the spaced arms and at least one tilt hydraulic ram may be provided to allow controlled relative movement between the arms and the implement bar.

The boom assembly may comprise a link arrangement between the pair of arms and the implement bar. The link arrangement may be such that a f irst end of the bar hydraulic ram is connected to one of the arms and a push link is connected between a second end of the tilt hydraulic ram and the implement bar. A slave link may be provided and may be connected between said one of the arms and the connection point between the push link and the second end of the tilt hydraulic ram.

The implement bar is arranged to carry a tool and pivotal movement between the pair of arms and the implement bar can allow a working angle of the tool to be selected.

The boom assembly may comprise two boom hydraulic rams and/or two tilt hydraulic rams. The hydraulic control means may be arranged so that a boom user input device controls both of the two boom hydraulic rams and/or a tilt user input device controls both of the two tilt hydraulic rams. One valve in the valve assembly may 6 control the supply of hydraulic fluid to both of the two boom hydraulic rams. One valve in the valve assembly may control the supply of hydraulic f luid to both of the tilt hydraulic rams.

The hull of the boat may comprises a main frame of box sections and may have a skin of welded plates. The bow may be shaped to facilitate maximum displacement and/or maximize stability when a load is placed on the boom assembly. The mainframe may be arranged to allow mounting of additional tools towards the stern.

The boat may comprise a weatherproof cab from which an operator may control the boat. The user input devices for controlling the remotely operable valve means may be disposed in the cab.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a schematic side view of a work boat; Figure 2 is a schematic plan view of the work boat shown in Figure 1; 7 Figure 3 is a schematic plan view of a tool for use with the work boat shown in Figure 1; Figure 4 is a fragmentary view of a blade of the tool 5 shown in Figure 3; Figure 5 is a side view of part of the boat shown in Figure 1 including more detail; Figure 6 is an exploded view of a boom arm of the boat shown in Figure 1; Figure 7 is a plan view of part of the boat shown in Figure 1 including more detail, Figure 8 is a schematic view of an implement bar of the boat shown in Figure 1; and Figure 9 is a schematic view of a hydraulic control 20 circuit of the boat shown in Figure 1.

Figures 1 and 2 schematically show a work boat which generally comprises a hull 1, an operator's cab 2, a boom assembly 3 and a pair of paddle wheels 4 which are 25 disposed on opposite sides of the boat.

8 The boom assembly 3 comprises a pair of spaced arms 5 at the distal ends of which is mounted an implement bar 6 which is arranged to carry a tool, for example, a clearing rake 7 as shown in Figures 1 and 2 or a weed cutting tool 8 as shown in Figures 3 and 4. The clearing rake 7 essentially comprises a number of curved elements 71 only some of which are shown in Figure 2, which are arranged in a frame 72 such that debris or vegetation can be scooped out of the water and off-loaded at a desired location. The weed cutting tool 8 shown in Figures 3 and 4 comprises an essentially D-shaped cutting member which is formed of two adjacent double edged saw toothed blades 81 and 82 which can be driven relative to one another to provide a scissor-like cutting action. With the weed cutting tool 8 mounted on the implement bar 6 the boat can be used to cut channels through vegetation growing in a canal. other tools may be mounted on the implement bar, for example, a platform on which workers can stand or a hammer for driving in bank reinforcing piles.

The paddle wheels 4 are used for propelling and manoeuvring the boat and are driven hydraulically. The position of the boom assembly 3 as a whole and the position of the implement bar 6 and hence any attached tool can be controlled by the user via a hydraulic 9 control system which is described in more detail below.

Figures 5, 6, 7 and 8 show various parts of the boat in more detail.

As shown in Figures 5 and 7 the cab comprises three windows 21, each of which is provided with a cover 22. In the case of the side windows the cover 22 is a hinged shutter and in the case of the front window the cover 22 is a removable plate.

The hull 1 comprises a main frame of steel box sections 11 which are welded together and are shown in dotted lines in Figure 5. A skin of welded plates 12 is attached to the main frame. The shape of the hull I and especially the bow of the boat is designed to maximise displacement and stability which are important bearing in mind the high loads which may be exerted on a tool attached to the implement bar 6. Further, mounting the arms 5 at positions removed from the bow of the boat aids stability when large loads are exerted on the ends of the boom assembly 3. The design of the hull 1, and in particular the use of a steel box 11 section main frame ensures that a large working surface area is provided and can allow the attachment of further tools at the stern of the boat.

Each of the arms 5 of the boom assembly 3 is mounted for pivotal movement on a respective bracket 31 provided just in front of the respective paddle wheel 4. As can be seen f rom Figure 6 each arm 5 has a double acting boom hydraulic ram 32 connected between the pivot bracket 31 and a boss plate 33. At a position beyond the boss plate 33 each of the arms 5 is cranked such that when the boat is in operation the free end of the arms 5 point down towards the water surface. In the region of the crank a second boss plate 34 is provided on each arm 5 to which a respective double acting tilt hydraulic ram 35 is mounted. At an end opposite to the second boss plate 34 each tilt ram 35 is connected to a respective push link 36 and slave link 37. The opposing end of the slave link 37 is connected to the respective arm 5 and the opposing end of the push link 6 is connected to a respective one of a pair of brackets 61 provided on the implement bar 6. Each of the implement bar brackets 61 is also connected to the distal end of the respective arm 5.

The attachment of the implement bar 6 to the arms 5 and hydraulic rams 35 via a link arrangement allows smoother controlled movement of the implement bar 6 and hence the tool 7,8. Further, the load holding capabilities of the device are improved.

It will be appreciated that by operating the boom hydraulic rams 32 it is possible to raise and lower the distal end of the boom assembly 3 as a whole as the arms 5 pivot about their mountings in the brackets 31.

Further, by operating the tilt hydraulic rams 36 it is possible to cause the implement bar 6 to pivot relative to the arms 5 so that the working angle of a tool 7, 8 attached to the boom 3 can be changed. This allows various operations, for example, a scooping action can be made with the rake 7.

Hydraulic hosing H and piping P is shown in Figure 6 for the supply of hydraulic fluid to the rams 32 and 35. Flexible hosing H is used where necessary across moving arcs (in the region of the hydraulic rams themselves and the pivot points between various components) but elsewhere rigid steel piping P is used. This minimises the risk of bursts occurring. At the same time the number of joints between hosing and piping is kept to a minimum.

Figure 8 shows the implement bar 6 in more detail. At least some of the tools used with the boat will require hydraulic drive. Thus hydraulic hosing H is provided from one of the arms 5 to the implement bar 6 where rigid 12 piping P runs to the mid-point of the bar 6 and terminates in connectors. Hosing H associated with an attached tool can be connected to the connectors. The implement bar 6 further comprises two tool supporting brackets 62 which are arranged to be engaged by corresponding hook means provided on a tool.

Figure 9 schematically shows the hydraulic control system used to control the boom assembly 3, the paddle wheels 4 and any hydraulic functions of a tool 7, 8 attached to the boom assembly 3. The hydraulic control system generally comprises a hydraulic fluid circuit and remote user operable controls which are located in the cab 2.

The hydraulic circuit 9 includes a common pump 91 which is driven by a diesel engine E and is used to supply hydraulic fluid to all of the hydraulic components provided on the boat. Hydraulic fluid is stored in a tank 92 from which it is drawn through a filter F by the pump 91. A service flow line 93 is provided from the pump 91 to a remotely operable spool valve assembly 94. A service return line 95 connects the spool valve assembly 94 via a filter F to the tank 92 to complete the service circuit.

13 A hydraulic tank filling pump 96 is provided and connected via a filter F to the pump 91 and the tank 92 to allow hydraulic f luid to be introduced into the system.

The pump 91 is a variable displacement pump which is controlled in accordance with a load sensing signal. A load sensing connection line LS is provided between the valve assembly 94 and the pump 91. As the load sensed at the valve assembly 94 changes, the amount of fluid supplied along the connection line LS changes due to the operation of a sensing valve (not shown) provided in the valve assembly 94. The displacement of the pump 91 changes in response to this change in supply along the line LS.

The valve assembly 94 comprises five two way spool valves each of which is controlled by a respective one of five joysticks 23 (see Figures 5 and 7). Each valve is a proportional valve so that the flow rate through it can be adjusted rather than it having simply open and shut states. Each joystick 23 controls the flow of hydraulic fluid to one of the respective components via the respective outlets 97 provided in the valve assembly 94.

As shown in Figure 9 respective pairs of outlets 97 are 14 connected via hydraulic lines 98 (which are implemented as piping and hosing P, H) to the hydraulically operated components provided on the boat. Thus a f irst pair of outlets is connected to the port paddle 4, a second pair of outlets is connected to the boom rams 32, a third pair of outlets is connected to the tilt rams 35, a fourth pair of outlets is connected to the starboard paddle 4 and the fifth and final pair of outlets is connected to the tool 7, 8 when this has a hydraulically operated function.

In the case of both the connections to the boom rams 32 and tilt rams 35 each of the respective lines 98 is split so that each of the boom outlets 97 is connected to both of the boom rams 32 and each of the tilt outlets 97 is connected to each of the tilt rams 35. This gives the necessary connections to the boom and tilt rams 32, 35 which are double acting and serves to ensure that when the user operates the boom joystick 23, both of the boom rams 32 act in unison and when the user operates the tilt joystick 23, both of the tilt rams 35 act in unison. This clearly makes the device easier to control than would be the case if the pair of boom rams 32 or pair of tilt rams 35 had to be operated independently of one another. Further this arrangement uses fewer valves than would be necessary if the lines were not split.

All of the valves in the valve assembly 94 are solenoid operated so electrical signals can be sent from the appropriate joysticks 23 to the remotely operable valve assembly 94 and all of the hydraulic circuit can be disposed in a region away from the operator and in particular outside the operator's cab 2. Whilst Figure 9 schematically shows the hydraulic circuit 9, the actual positions of the components concerned can be seen from Figure 7, i.e. towards the stern of the boat and housed below deck level. The positioning of the hydraulic circuit 9 away from the operator greatly improves safety and ensures that no hydraulic fluid contamination will occur within the worker's cab 2. The engine E, pump 91 and hydraulic fluid tank 92 act as ballast and can be positioned to aid stability.

Because the pump 91 is a variable displacement pump and has load sensing capabilities an appropriate supply of hydraulic fluid to all components can be ensured irrespective of the number of hydraulic components which are being operated at any one time.

Safety valves (not shown) are provided at the boom and 16 tilt rams 32, 35 which prevent movement of the boom assembly 3 and attached tool in the event of power shutdown/failure or pipe/hose failure.

The electric control circuitry including the joysticks 23 includes an isolator switch disposed in the cab 2 which is operable by a user and when operated locks all of the controls such that a user cannot (inadvertently) operate any of the hydraulic devices and moreover such that all of the hydraulic devices are held in a static position. This state is retained until the isolator switch is cleared once the circumstances which caused its operation have been removed for example, once an obstruction has been moved or a fault has been rectified.

17

Claims

1. A work boat for carrying out maintenance work on canals and other waterways comprising a boom assembly arranged to carry a tool and user operable hydraulic control means for controlling the boom assembly to allow location of any tool mounted on the boom assembly in a desired working position.

2. A work boat according to claim I in which the shape of the hull is designed to maximise displacement and stability.

3. A work boat according to claim I or claim 2 in which the boom assembly comprises an implement bar for supporting a tool and the beam of the boat is substantially equal to the length of the implement bar. 15

4. A work boat according to any preceding claim in which the boom assembly comprises a pair of spaced arms which are pivotally mounted on the hull of the boat, wherein the mountings for the pair of arms are disposed towards the midpoint between the bow and stem to aid stability. 20

5. A work boat according to any preceding claim in which the hull is 6 substantially enclosed, a skin of plates being attached to a main frame.

6. A work boat according to any preceding claim in which an engine, hydraulic pump and hydraulic fluid tank are positioned below deck level to aid stability.

7. A work boat according to any preceding claim in which the hydraulic control means includes a hydraulic fluid circuit comprising pumping means, a plurality of actuators for driving components, interconnecting piping, and remotely operable valve means.

S. A work boat according to claim 7 in which the hydraulic control means comprises at least one user input device which is arranged for controlling the valve means and disposed at a location away from the hydraulic fluid circuit. 15 9. A work boat according to any preceding claim which comprises hydraulically operated propulsion means for propelling the boat.