Patent Application
20150159350
The present invention relates to a cutter head, and blade, for a dredger, and to an associated tool holder for blades for a dredger. In addition, the invention relates to a tool arrangement on a blade or a cutter head for a dredger. The invention further relates to a method of mounting a tool holder in a cutter head for a dredger. In addition thereto, the invention relates to a production method for blades or the cutter heads for a dredger comprising an adapter chamber.
Devices for dredging are used to displace, dig up or suck up material or sediment wholly or partially in liquid, for example in water. One example of a device for dredging is a dredger. Different types of dredger are designed for different applications and can comprise a large assortment of different mechanical machining methods for displacing, digging up or sucking up the material or the sediment. For example, dredgers can be based on different types of digging methods, such as, for example, different variants of buckets, drilling methods with different types of drills, pneumatic or hydraulic devices, as well as suction devices. Since the material and the sediments are of different nature, hardness and quantity, different methods are required to displace, dig up or suck up the material or the sediment. There are also different reasons for the working of the material or the sediment, wherein the removal of the material is in certain cases desired, such as in the dredging of a canal, for example. Other reasons for dredging are recovery of the material or sediment as raw material, for example the recovery of sand or metals or other substances in sand or other sediment.
For dredgers designed to machine the material or sediment with tools, the tools with which the dredgers are equipped in most cases become worn. The tools are configured to machine in different ways the material or sediment worked by the dredger. The tools are mounted in a tool holder and constantly replaced. Forces acting on the tool affect the tool holder and, after prolonged use, the tool holder may also need to be changed. A rule of thumb is that a tool holder needs to be changed after fifty tools have been worn out. The tool holder can need to be changed, however, before fifty tools are worn out, and the tool holder can also last for a significantly greater number of tools than fifty.
Traditionally, the tool holder is welded onto a cutter head. Dredgers equipped with the cutter heads are especially configured for dredging when the material or sediment is of such hardness that mechanical machining is required. A cutter head preferably consists of a number of blades, which preferably, in a spiral shape, pass from the base of the cutter head so as to jointly converge in the tip of the cutter head. On the blades of the cutter head, tool holders with tools are mounted or constructed. The tools are configured to machine the material or sediment worked by the cutter head, and thus the dredger.
The cutter heads for dredgers are often produced by casting, wherein, after the production of the cutter head, a tool holder is mounted on the cutter head. Assembly of the tool holder is preferably realized with welding or other thermal jointing methods. The placement of the tool holders is preferably realized by the assembly of templates or jigs which place and, prior to the assembly, fix the tool on the cutter head. Once the tool holder is temporarily fixed by the template or the jig, then welding of the tool holder onto the cutter head can take place. After the tool holder has been welded onto the cutter head, the template or jig can be disassembled and moved from the cutter head, or to another place on the cutter head, for further assembly of additional tool holders. Once all tool holders have been welded onto the cutter head, the tools can be mounted in the tool holders and the cutter head is ready for use on the dredger.
Patent document U.S. Pat. No. 4,470,210 describes a method and a device for mounting of a tool holder in an adapter, in which the adapter is configured in a spiral blade on a cutter head. A tooth having a tip is mounted on the tool holder, which tooth can be easily replaced in the event of wear, since the tooth is mounted with a lock.
The tooth is oriented in the tool holder with two lugs constructed in the tooth. The adapter has a recess in which the tool holder is mounted. The tool holder is mounted against a wall in the adapter and the space between the tool holder and the adapter is expediently filled with epoxy, which, after hardening, temporarily fixes the tool holder in the adapter, whereupon the tool holder is welded to the adapter. In the invention described in patent document U.S. Pat. No. 4,470,210, the change of the tool holder presupposes that the tool holder is fixed with epoxy in the adapter and is welded to the adapter, which involves extensive work by qualified staff on a cutter head removed from the dredger whenever the tool holder or tool holders is/are replaced.
An example of a patent document which describes a tool holder is U.S. Pat. No. 4,337,980. The patent document describes a tool holder in which the tool or the tool holder is mounted with a screw joint in a base member. The base member is, in turn, fixedly mounted on a mining machine, road-making machine or construction machine. The tool holder is mounted in the base member with a screw joint. Both the tool holder and the tools are circularly symmetric. It is proposed that the tool holder can have many different versions of the cross-sectional area of the tool holder in order to fix the tool holder in the base member. The invention described in patent document U.S. Pat. No. 4,337,980 presents a tool holder which is mounted in a base member, in which the base member is in itself mounted on a machine. The base member is arranged free from the machine and the tool holder/the tool is screwed to the base member and the threaded joint is arranged open. The tool holder is suitable for mining machines, road-making machines and construction machines.
Patent document U.S. Pat. No. 2,385,395 describes a device for mounting a tool in the form of an excavating tooth in a tool holder. The excavating tooth has a threaded part or a screw mounted in the excavating tooth, which is mounted with detaining elements in the form of a nut and a wedge. The excavating tooth is mounted on a bucket and the tool holder is a part of the lip of the bucket.
One object of the present invention is to propose a cutter head for a dredger constructed with a recess for mounting of a tool holder, in which the tool holder is mounted with a screw joint and mounting of a tool holder on a dredger can be realized without the tool holder being welded, or otherwise thermally mounted, on the cutter head.
Other objects of the invention are described in greater detail in connection with the detailed description of the invention.
The invention relates to a cutter head for a dredger, in which the cutter head is constructed with at least one blade and at least one adapter chamber is arranged in the blade for assembly of a tool holder in the blade, in which the adapter chamber is a cavity configured in the blade and having an opening and an assembly recess.
According to further aspects of the improved cutter head for a dredger:
the opening of the adapter chamber is made in the edge of the blade, and the extent of the adapter chamber is in the direction along the spine of the blade,
the assembly recess is arranged close to the inner end position of the adapter chamber, in which the assembly recess is wholly or partially penetrative of the blade in the direction through the blade spine,
the adapter chamber is conically configured and tapered towards the assembly recess.
The invention is further constituted by a blade for a cutter head for a dredger, in which the blade is constructed with at least one adapter chamber, arranged in the blade, for assembly of a tool holder in the blade, in which the adapter chamber is a cavity configured in the blade and having an opening and an assembly recess.
According to further aspects of the improved blade for the cutter heads:
the opening of the adapter chamber is made in the edge of the blade, and the extent of the adapter chamber is in the direction along the spine of the blade,
the assembly recess is arranged close to the inner end position of the adapter chamber, in which the assembly recess is wholly or partially penetrative of the blade in the direction through the blade spine,
the adapter chamber is conically configured and tapered towards the assembly recess.
The invention is further constituted by a tool holder for assembly on a cutter head for a dredger, in which the tool holder is configured to fit an adapter chamber constructed in the cutter head.
According to further aspects of the improved tool holder for assembly on the cutter heads:
the tool holder is conically configured to fit an adapter chamber constructed in the cutter head, and the tool holder is constructed with a mounting device for assembly of the tool holder on the cutter head,
the mounting device of the tool holder, for assembly of the tool holder on the cutter head, is a threaded end piece constructed on the tool holder,
the mounting device of the tool holder, for assembly of the tool holder on the cutter head, is an assembly recess, constructed on the tool holder, for a wedge.
The invention is further constituted by a tool arrangement for a dredger, in which at least one tool holder is mounted with a locking mechanism in an adapter chamber constructed on a blade on a cutter head, in which the adapter chamber is a cavity configured in the blade and having an opening and an assembly recess, and in which a tool, for dredging, is mounted on the tool holder.
According to further aspects of the improved tool arrangement for a dredger:
the locking mechanism is a threaded joint, the locking mechanism is a cottered joint,
inlays are used between the tools and the tool holder or between the adapter chamber and the tool holder.
The invention is further constituted by a method for assembly of a tool holder in a cutter head for a dredger, in which:
a) the tool holder is mounted and oriented in an opening, made on the cutter head, to an adapter chamber, in which the adapter chamber is constructed in a cavity on a blade on the cutter head, and
b) the tool holder is fixed with a locking mechanism which is mounted in an assembly recess configured on the cutter head and constructed on the blade on the cutter head.
The invention is further constituted by a production method for a blade for a cutter head for a dredger, in which an adapter chamber for assembly of a tool holder is machined by:
a) the blade for the cutter head, or the whole of the cutter head, being die-cast with a cavity for an adapter chamber and an assembly recess,
b) the blade, or the whole of the cutter head, being mounted, after casting, in a machine tool,
c) the bearing surfaces of the adapter chamber being machined with the machine tool.
The invention will be described in greater detail below with reference to the appended figures, in which:
a and
a shows an adapter chamber in section, with tool holder and mounting device according to one embodiment of the invention,
On the cutter head 30 of the dredger, also referred to as the cutting head, one or more adapter chambers 11 are constructed on one of the blades 10 of the cutter head. A cutter head 30 has a number of blades 10 or arms, which are mounted in part in a hub 41, in the tip of the cutter head, and in part in a ring 40 in the base of the cutter head. The blades 10 are gathered in the hub 41 and the hub 41 is preferably constructed with a thread for assembly of the cutter head 30 in the dredger and for force transfer from the dredger to the cutter head 30. Normally a cutter head 30 for a dredger consists of an even number of blades 10, in which two different versions of the blades are found. Where two different blades are used, the two different blades have separate positioning of the adapter chamber 11, and thus also separate positioning of the tools 50, also referred to as the teeth, in order that the cutter head 30 shall acquire a suitable construction for machining. On each blade is arranged a number of tools 50 and tool holders 20 for working of the material or sediment which the cutter head is meant to machine. The blades on the cutter head 30 give rise to the formation of a number of openings 39 between the individual blades 31, 32, 33, 34, 35, 36 on the cutter head, in which openings the sediment or dredged material which is machined can be evacuated or otherwise transported away from the cutter head and thus the machining zone. Each blade has a spine 37 and an edge 38 which is directed towards the machining direction for the cutter head.
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Various types of inlays, also referred to as liners or inserts, 5, 5′, 5″, 5′″, 5″″ can be used to absorb forces between the tool holder 20 and the adapter chamber 11 and/or between the tool 50 and the tool holder 20. By adapting the choice of material for the inlays, the wear can be shifted from the tools, and the tool holder, so that the inlays become worn first. In an advantageous embodiment, the inlays 5, 5′, 5″, 5′″, 5″″ can be made of a material which is softer than the tool 50 but harder than the tool holder 20. In addition, the inlays can act as supporting parts for worn tools or tool holders, so that the tools and the tool holders can be used longer and can thus acquire a longer service life. The inlays 5, 5′, 5″, 5′″, 5″″ are preferably used on surfaces which are exposed to high surface pressure and the inlays become deformed during use and are replaced when worn out. They are worn out once the extent of the deformation is such that the inlays 5, 5′, 5″, 5′″, 5′″ no longer fulfil their function. The inlays 5, 5′, 5″, 5′″, 5″″ are preferably produced in a number of standard dimensions and are adapted according to how wear is generated between the tool 50 and the tool holder 20 and between the tool holder 20 and the adapter chamber 11. The inlays 5, 5′, 5″, 5′″, 5″″ are expediently mounted with mechanical connection, for example screw joints, spot-welded, glued or otherwise mounted in their correct position. The inlays 5, 5′, 5″, 5′″, 5″″ can also be placed in their correct position without fixing.
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The tool holders are mounted in the cutter head by placement of the tool holder 20 into a suitable adapter chamber 11. As a result of the construction of the adapter chamber, the tool holder will be oriented by the bearing surfaces 12, 17, 18 and the correspondingly oriented surfaces 22, 23, 24, 28 of the tool holder. Once the tool holder is correctly positioned, the mounting device 27 will also become visible in the assembly recess 16. On the mounting device, the cone 2, the washer 4 and, finally, the nut 3 can then be mounted. Where a wedge (not shown in the figures) has been used, then the recess of the mounting device for a wedge will be visible in the assembly recess. The wedge is subsequently placed in the mounting device 27 and forced with suitable equipment, for example a sledge hammer, so that the wedge locks the tool holder 20 in place in the adapter chamber 11. The wedge-based assembly method is referred to as a cottered joint. Where a threaded joint is used, then the nut 3 is screwed with suitable equipment, for example a hydraulic or pneumatic nut tightener, to a predefined torque. Where no pneumatic or hydraulic nut tightener is present, a suitable ratchet handle or other equipment is used to tighten the nut 3 to a suitable torque. The tool holders can be mounted and replaced once the cutter head is mounted on the dredger. The positioning of the tool holders can be realized with great accuracy when the adapter chamber is machined for a good fit, especially compared with the case in which the tool holders are welded onto the blades. When no welding or cutting of the tool holders takes place, the change of tool holder becomes more environmentally friendly. Welding/cutting requires gases, which can be avoided if the tool holders are mounted with a cottered or threaded joint. The tool holders can also be easily removed from the cutter head and repaired in order to further prolong the service life. Where the tool holders are cut away from the cutter head, then this very often results in the discarding of the tool holders.
In one example of the construction of a cutter head for a dredger, the cutter head has 6 blades, whilst 5 or 7 blades are also commonly found, in addition to which cutter heads for dredgers having a different number of blades are also found. The usual number of teeth on the cutter head, and thus also the number of tool holders, is 60. The number of teeth can be freely varied, however, depending on the application, dredger construction, or depending on the nature of the dredged material. The tool holder is often mounted with nuts in the order of magnitude of M60, but can be arbitrarily varied according to application, dredger construction, or depending on the nature of the dredged material or the construction of the tools and tool holders. Following assembly of the tool holders, the tools are mounted into the tool holders.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1230055-4 | May 2012 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/SE2013/000087 | 5/28/2013 | WO | 00 |
