Patent Application
20060101953
The present invention relates, in a first aspect, to a tool holder for tools for cranes, which tool holder comprises hydraulic cylinder means arranged to detachably be able to lock a tool to the tool holder, hydraulic coupling means arranged to be connected with hydraulic coupling member on tools and hydraulic line means.
In a second aspect, the invention relates to a crane provided with the invented tool holder and in a third aspect to use of the invented tool holder.
Tool holders of the corresponding type are used also at different types of contractor's machinery such as excavators, wheel loaders, movers of material and the like machine types. A complication at tool holders for cranes such as, e.g., lorry cranes is that the tools are pendulum suspended, the tool holder being provided with a hydraulic rotator. Such a one is required at timber grip, clamshell bucket, pallet forks and other similar tools.
At conventional tool holders for cranes, hydraulic lines are run to the tool holder for the hydraulic manoeuvre of the tool as well as for manoeuvre of the locking mechanism of the tool holder. Since the locking mechanism consists of one or more double-acting hydraulic cylinders, two hydraulic lines are normally run for the locking function. With two or more hydraulic lines for manoeuvre of the tool, it means that at least four hydraulic lines are run to the tool holder. This implies a relatively complicated, and thereby expensive arrangement. On one hand because the hydraulic lines have to be run up along the entire crane jib, which becomes additionally cumbersome in connection with lorry cranes having a plurality of crane jib projections. And on the other hand because the rotators that most cranes are equipped with, normally only has one pair of swivel fairleads. For manoeuvre of the locking mechanism, additionally two swivel fairleads are required. It means that the rotator has to be provided with four coil ducts in the swivel, which implies a complication and price increase.
Tool holders of the above-mentioned type are manufactured by OilQuick AB at a system called OQ 60 and by Liebherr at a system called Topas.
Furthermore, a tool holder is previously known manufactured by HEVO Parts AB, at which the hydraulic hose problems are handled in a different way. In that connection, a hydraulic cylinder is integrated in the tool holder, which also serves as tool cylinder. By utilizing the existing work hydraulics under the rotator in this way, no connection of hoses at operation with, e.g., clamshell bucket and pallet forks is needed. At all other types of hydraulic tools, such as earth drill, vibrating tamper, etc., the hydraulic hoses, however, have to be connected as usual by hand. To interconnect hydraulic hoses by hand frequently involves problems, because of back-pressure in the lines as well as general oil mess. A disadvantage of said holder is that only specially adapted tools can be used in connection with the holder. Also size and weight of the holder are experienced as a disadvantage. The holder has mechanical locking, which is made by the operator by hand on site. By this holder, the hydraulic hose problems are partly solved.
The object of the present invention is to provide a tool holder of the kind in question, at which the disadvantages that are associated with previously known tool holders of the corresponding type are eliminated.
The object set up has, according to the present invention, been attained by the fact that a tool holder of the kind defined in the preamble of claim 1 has the special features that the tool holder comprises valve means provided with switching means arranged to connect the hydraulic line means to either the hydraulic cylinder means or to the hydraulic coupling means of the tool holder.
Thanks to the switchable valve means, the hydraulic lines to the tool holder may serve the double purpose of manoeuvring the locking mechanism as well as manoeuvring the tool. Thereby, the number of requisite hydraulic lines of the hydraulic line means is reduced, the number of lines may, for instance, be reduced from four to two. This decreases the extent of running hydraulic lines along the crane jib as well as the number of swivel fairleads, so that the construction becomes simpler, and thereby more inexpensive.
With a tool holder according to the invention, it is enabled to provide an optimal tool holder system for cranes, especially lorry cranes that comply with those requirements being appropriate to put on such a one, viz.:
According to a preferred embodiment of the invented tool holder, the cylinder means comprises two double-acting hydraulic cylinders. It may be enough, per se, with only one such hydraulic cylinder. However, the locking becomes less stable or supplementation of the locking by providing the hydraulic cylinder with a mechanical branching is required in order to obtain two-point locking. However, with two hydraulic cylinders the locking becomes simpler. Having more than two hydraulic cylinders is unnecessary and risks leading to an overdetermination of the locking position. By the fact that the hydraulic cylinders are double-acting, the locking and release function, respectively, is achieved in a smooth way.
According to an additional preferred embodiment, the hydraulic coupling means comprises at least two coupling units and the hydraulic line means at least two hydraulic lines. This is an expedient embodiment since the manoeuvre of the tool in most cases requires more than one hydraulic line.
According to an additional preferred embodiment, each hydraulic coupling unit is connected to the valve means by a hydraulic coupling line and each hydraulic cylinder is connected to the valve means by at least one hydraulic cylinder line, a connection line being arranged between each hydraulic coupling line and one of the hydraulic cylinder lines where a non-return valve is arranged in each connection line, which non-return valve is directed in such a way that it enables flow from the hydraulic coupling line to the hydraulic cylinder line but not in the opposite direction. By the by-pass function that is achieved by this embodiment, it is guaranteed that the pressure in the hydraulic cylinders in locking position is maintained when the hydraulic lines after the locking operation have been switched to connection to the hydraulic coupling member of the tool. Thereby, it is guaranteed in a simple way that the tool is locked to the tool holder during operation.
According to an additional preferred embodiment, the switching member is arranged for manual switching of the connection of the valve means. This represents a simple and safe switching that eliminates the need for running electric cables along the crane jib for manoeuvre of the valve means.
According to an additional preferred embodiment, the switching means is provided with remote-controlled driving means for switching the connection of the valve means. This embodiment may constitute a complement or alternative to the closest above-described embodiment and eliminates the need for the operator to leave the operator seat thereof at switching the valve means.
Above-mentioned preferred embodiments of the invented tool holder are defined in the claims depending on claim 1.
The crane and the use according to the present invention have advantages of the corresponding type as has been given above for the invented tool holder and the preferred embodiments of the same.
The invention is explained closer by the subsequent detailed description of advantageous embodiment examples of the same while referring to the appended drawings.
The tool 3 may be released from the tool holder and be replaced by another kind of tool. The invention is intended to enable such a tool change in an optimal way.
The tool holder is illustrated more in detail in
On the tool gate 3a, there are two bars (not shown), which are located in order to co-operate with the recesses 12 and the L-profiles 13a, 13b, respectively. When a tool is to be connected to the tool holder, the same are positioned so that the U-shaped recesses engage one bar of the tool gate 3a. Next, the tool and the tool holder are turned in relation to each other around said bar until the second bar of the tool gate is situated in the L-profiles. In this position, hydraulic cylinders are activated, which project the lock plungers 14a, 14b so that the second bar becomes located in the U-profile then formed. In the same position, the tool is locked to the tool holder. Furthermore, the hydraulic coupling unit on the tool holder has been brought to connection with hydraulic coupling units on the tool. The sequence of operations described hitherto for the connection is the state of the art.
At the tool holder according to the invention, a valve plate 9 is mounted on the tool holder. The valve plate 9 can be manoeuvred by means of two levers 10, 10b. By means of these, the hydraulic lines which lead from the hydraulic source of power to the tool holder can be switched to connect either to the hydraulic cylinders that manoeuvre the locking or to the hydraulic coupling units that are connected with corresponding units on the tool. In the position shown in
Said position is illustrated in
In
The principle of the invention should most clearly be seen in the hydraulic schemes in
When the locking phase is accomplished, the valves 9a, 9b are switched to the position shown in
When the tool is to be released from tool holder, for instance for exchange of tool, the valves are switched to the position shown in
The switching of the valves 9a, 9b is carried out by the levers 10a, 10b illustrated in
As alternative to manual switching by means of the levers 10a, 10b, a battery-driven motor may be arranged in connection with the valve plate in order to displace positions of the valves. This is suitably operated by wireless remote control.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0300229-2 | Jan 2003 | SE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/SE04/00117 | 1/29/2004 | WO | 7/27/2005 |
