The present invention concerns a device for attaching a first part in the form of an instrument or tool to a second part in the form of a beam or such on a working machine according to the preamble of the attached claim 1.
The working machine can be of any type and trucks, front loaders, digging machines and demolition machines can be mentioned as examples, which in general are supplied with different types of working instruments or tools. Examples of such instruments are forks of different types, scoops, clamping units, man baskets, lever arms and other special types of equipment for handling special loads.
An attachment device of the type defined in the introduction is usually called “rapid attachment”, because the attachment of instruments to the working machine can occur relatively quickly by making said engagement and then utilizing force of gravity to fixedly hold the instrument at the working machine's beam or such. “Engagement” is to be understood to have a broad meaning and can for example mean that hooks on the working instrument are held under the force of gravity and are clamped onto an outer edge of the holding frame of the working machine's beam and the instrument is held against the frame and supported by the frame in some additional position. Such so-called rapid attachments are used for tools and instruments such as scoops, lever arms and other tools, which do not require any separate machine operation of any type. In prior art devices for attaching an instrument or a tool to a beam or such on a working machine according to the preamble of claim 1 there is a risk that the instrument or tool will gradually become more loosely attached on said beam or such because of the effect of the operation of the working machine on the device itself.
The aim of the present invention is to provide a device of the type defined in the introduction, which remedies the above-mentioned inconveniences associated with such prior art devices.
This aim is achieved according to the invention by providing such a device with the features that are given in the characterizing part of claim 1.
By providing the fixedly locking arrangement with resilient members in combination with the wedge element the gap in the attachment will constantly be automatically eliminated, because the resilient member constantly ensures that the wedge element is pushed as far as possible into the recess. Consequently the invention solves the problem effectively using surprisingly simple means.
The wedge element's wedge form is thereby preferably such that the wedge element will be pushed into the recess under the action of the internal walls of the recess in such a direction that the part that is provided with the recess is pushed with its engagement means having surfaces converging towards each other into an engagement-making direction.
According to another preferred embodiment of the invention the device also comprises controllable power means for transferring the locking arrangement between an inactive position and an active position with the wedge element pushed into the recess and held during pre-loading. The wedge element can hereby be held back and is not in the way of the insertion of the first engagement means in the second engagement means and it is then driven to the active locking position via the operation of the power means.
According to another preferred embodiment of the invention the locking arrangement connected with the wedge element comprises, a dead centre defining means, and the power means is designed to influence said dead centre means to transfer the wedge element from an inactive position to an active position located on the opposite side of a dead centre, in which the resilient member is solely responsible for holding the wedge element in the recess. The holding in locking position is hereby very reliable, as it does not depend on the power means being supplied with energy.
Advantageously the wedge element is arranged on the second part, i.e. the working machine, and the recess is arranged on the first part, i.e. the instrument or the tool.
According to a preferred embodiment of the invention the second, female-type engagement means has two opposite walls, converging towards one another, which laterally restrict a channel directed substantially vertically in the normal direction of the first part when attached to the second part and form said converging internal surfaces. Arranging the converging surfaces in this way results in a very stable holding of the first part in the second part. It is thereby advantageous that an internal large surface part of the second engagement means, that is substantially planar, forms the bottom of the canal and contacts an external surface part of the fist engagement means, that is substantially planar, in the locked position. It is especially advantageous if two other walls, at least partly restricting the canal, extend substantially at a right angle relative to the formerly mentioned walls and converge towards each other to form said converging internal surfaces, since such a convergence of two planes lying cross-wise with respect to each other results in a very distinct locked position of the first part in the second part. It is more specially preferred if the other walls are formed from said substantially planar large surface parts.
According to another preferred embodiment of the invention the second, female-type engagement means has an opening intended to be turned towards the other part in a direction substantially perpendicular to the direction of convergence of this engagement means' converging surfaces during the engagement operation to facilitate the insertion of the male-type engagement means in the female-type engagement means. The driver of a working machine can hereby rapidly force the first engagement means into the second and lock the first part at the second part without nerve racking precision work being required.
Further advantages and advantageous features of the invention will be apparent from the following description and the other dependent claims.
Preferred embodiments of the invention are described below by way of example with reference to the attached drawings, in which:
The locking arrangement has, on one hand, a recess 19 in the form of a through-hole arranged in the instrument part, more particularly in the planar surface part 8, and, on the other hand, a locking unit arranged in the working machine's attachment frame 12. The locking unit has a wedge element 20 that is movably controlled via a control means 21 to move out of the frame 12 for insertion into the recess 19 to an active locking position and out of the recess to an inactive position. For this reason the locking element is connected to a dead-centre-defining toggle joint 22, between whose one end 23 and a stop bolt a compression spring 24 is arranged. The locking arrangement even has a power means 25 in the form of a hydraulic cylinder, whose piston rod is connected to the toggle joint device's 22 toggle joint.
The function of the locking arrangement is as follows. When this is in the active position shown in
The inventive device therefore provides the possibility to achieve a play-free attachment and locking of an instrument to a beam or such of a working machine according to the rapid attachment principle, i.e. without the driver having to leave the driver's cabin of the working machine.
The invention is of course not in any way limited to the preferred embodiment described above, but a number of modification possibilities thereof should be apparent for a person skilled in the art, without having to deviate from the basic idea of the invention as defined in the attached claims.
For example it would be completely possible to arrange the female-type engagement means on the beam or such and the male-type engagement means on the instrument instead, and these would then have the shape of a V instead of an inverted V.
It is even, in principle, possible for the engagement means to have fewer or more converging surfaces than what has been illustrated above. In principle substantially cone-formed male type engagement means would be possible, even if the above described embodiments are preferred in relation thereto because of the possibility of more simply inserting the female-type means and probably even of attaining a better stability in the attached position.
As regards the use of the words “upward” and “vertical” in this document these words relate to the usual position which the working machine and the instrument have when they are resting on horizontal ground, and departure from said directions will of course occur when the working machine and/or the instrument are/is otherwise directed.
Number | Date | Country | Kind |
---|---|---|---|
0202205-1 | Jul 2002 | SE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/SE03/01212 | 7/15/2003 | WO | 1/13/2005 |