AN ARRANGEMENT FOR SECURING A MOUNTING PART FOR A LOAD-HANDLING DEVICE

Abstract: The invention relates to an arrangement for securing, in a parking position, a part (3) of an implement attachment to the free end (2f) of a crane arm (2e), wherein said implement attachment part (3) is pivotally mounted on said free end (2f) by means of at least one pivot shaft (6a, 6b), wherein said implement attachment part (3) comprises at least two parts (3a, 3b) which are rotatable relative to each other, and wherein said parts are adapted for rotation in relation to each other by means of a piston-cylinder device (7). At least one tension-force take-up device (4a, 4b) is mounted between a securing device (10) associated with the implement attachment part and a securing device (11a, 11b) associated with the crane arm. Activation of the piston cylinder device (7) can bring the implement attachment part (3) to a parking position beneath or above the crane arm (2e).

Description: AN ARRANGEMENT FOR SECURING A MOUNTING PART FOR A LOAD- HANDLING DEVICE Field of invention The present invention relates generally to an arrangement for securing an implement attachment, and more particularly to an arrangement for securing a part of an implement attachment means. The invention is concerned with such an arrangement that functions to hold securely a part of an implement attachment or implement holding means to the free end of a crane arm in a so-called parking position. By parking position is meant a position or a setting of the implement attachment and its part associated with the crane arm in a transport-adapted position. In the case of an arrangement of this kind, said part of the implement at- tachment is pivotally mounted to the free end of the crane arm via at least one pivot shaft. The invention is also based on an arrangement in which said part of the implement attachment may consist in or co-act with at least two parts that can rotate relative to each other, and in which said parts are adapted for rotation relative to each other about a pivot shaft through the medium of a piston-cylinder device. Said part of the implement attachment is included in a two-part coupling arrangement as a first part, and is adapted for co-action with an implement- associated second part, this second part not being described in detail in this document. Description of the background art Several different crane-arm constructions that can be conveniently adapted for fixation to an automotive vehicle, normally trucks, are known to the art. These crane-arm arrangements are constructed to enable them to be accommo- dated between the rear part of the driver's cabin and the front portion of the loading platform of the truck in a folded state or a parked state (parking position). Normally, a crane-arm arrangement of this kind will include a vertical part whose bottom end is fastened to the chassis of a truck and whose upper part includes means for pivotal co-action with one end of an arm, whose other end can pivotally co-act with a dipper stick whose free end pivotally carries a first implement-securing part of a two-part coupling arrangement. It will be evident in this regard that diverse efforts have been made to obtain such a crane-arm arrangement that will be as compact as possible in a parked position, but which is nevertheless dimensioned for heavy loads, primarily with regard to lifting goods from a position in which the crane arm and dipper stick and/or other parts are fully extended. Also known to the art are different kinds of two-part implement attachments of which one part can normally be mounted on the free end of the crane arm or the dipper stick . The implement attachments may have different forms and different sizes for respective applications. The present invention is based on the use of more complex implement attachments, in other words on the use of implement attachments that include an at- tachment part which is integrated with a rotating component and which is therefore relatively space-demanding. For implement attachment parts of the kind in question, particularly where one part of said attachment consists in at least two parts that are rotatable relative to one another, and where the parts of a piston-cylinder device are adapted for ro- tation relative to one another, it has been necessary in practice to dismantle said attachment parts before the crane-arm arrangement can be folded together or collapsed into a parking state. Alternatively, the crane-arm arrangement cannot be folded together or collapsed into a parking state, but must take another more open state, which experience has shown can result in damage. The crane arrangement marketed by HIAB-FOCO, Hudiksvall, Sweden, can be mentioned as an example of a crane-arm arrangement that can be fitted to trucks. Several different types of implement attachments are known to the art, and with regard to the following description it can be mentioned that one such imple- ment attachment is illustrated and described in International Patent Application PCT/SE99/02235 corresponding to Swedish Patent Application No. 99 02120-6. Such implement attachments also comprise one part associated with the implement and one part associated with a crane-arm, where the latter part is significant to the present invention. Summary of the present invention Technical problem When taking into consideration the technical deliberations that a person skilled in this particular art must make in order to find a solution to one or more technical problems that he/she encounters, it will be seen that it is necessary initially to realise the measures and/or the sequence of measures that must be undertaken to this end on the one hand, and on the other hand to realise which means is/are required to solve one or more of said problems. On this basis, it will be evident that the technical problems listed below are highly relevant to the development of the present invention. When considering the present state of the art, as described above, it will be seen that a technical problem resides in provisions, created with the aid of simple means, which allow an implement attachment part, connected to the free end of a crane arm and having a more voluminous and complicated form, to be readily accommodated between the rear part of a lorry cabin and the front part of a loading platform when fitted to the free end of the crane arm or the dipper stick, and which enable the arm-portions of the crane-arm arrangement to be folded fully to a parking position or state. Another technical problem is one of realising the significance of and the advantages afforded by creating conditions that will enable said implement attachment part to take a folded-in position in said parking state that connects with the free end of the crane arm or dipper stick . Another technical problem is one of realising the significance of and the advantages gained by utilising a device that extends between the front part of said crane-arm arrangement or said dipper stick and the implement attachment part, for achieving said connecting and inwardly folded position. Another technical problem is one of realising the significance of and the advantages gained by clamping said attachment part against the crane arm or said dipper stick in said parking state, with the aid of said device and a piston- cylinder device. Another technical problem is one of realising the significance of and the advantages gained by providing at least one tension-force take-up device between a first securing device associated with said implement attachment part and a sec- ond securing device associated with the dipper stick . In this regard, a technical problem resides in realising the significance of and the advantages gained by causing said implement attachment part to be brought to a parking position beneath the crane arm and said dipper stick with the aid of said tension force take-up device upon actuation of the piston-cylinder device. Another technical problem resides in realising the significance of and the advantages afforded by the use of two tension-force take-up devices, a first device for rotating the implement attachment about a first pivot shaft, and a second de- vice for lateral orientation or lateral rotation of the implement attachment about a second pivot shaft. In this regard, a technical a problem resides in realising the significance of and the advantages associated with making the first device shorter than the second device, wherewith at least one of said devices may consist of a chain. Another technical problem is one of realising the significance of and the advantages that are gained by enabling the length of one such device to be adjustable, by means of a bottlescrew or some corresponding means, so that a relative length adjustment of the two tension-force take-up devices can be achieved according to the application concerned. Another technical problem resides in realising the significance of providing at least one rotor unit, a first pivot shaft, a link, and a second pivot shaft between the said implement attachment part and the free end of said arm or dipper stick . In this regard, a technical problem resides in realising the significance of and the advantages associated with pivotally mounting a generally U-shaped ele- ment on the free end of the arm or the dipper stick , and to provide on said element a holder for holding said first pivot shaft. Another technical problem is one of realising the significance of and the advantages associated with enabling the pivotal attachment of said U-shaped element to be adjustable backwards and forwards along the extension of the crane-arm arrangement, so as to enable the parking position of said implement attachment part to be regulated and adjusted. It will also be seen that a technical problem resides in realising the significance of fastening a first tension-force take-up device to a fixed part of the crane arm or dipper stick, and to fasten a second tension-force take-up device to an ex- tension of said generally U-shaped element in a direction towards the fixed part of a crane-arm arrangement. In the case of an arrangement of the aforedescribed kind that succeeds in solving one or more of the aforesaid technical problems, it will be seen that a technical problem resides in applying this solution to a special crane-arm arrangement that has a pivotal arm at both ends thereof and a dipper stick fixed to one end of the arm and orientated in the close proximity thereof but in a vertical plane located laterally of the vertical plane of said arm, and to provide provisions such that the implement attachment part in a parking position or when moving to- wards said parking position can be so orientated laterally or so pivoted laterally about a pivot shaft as to enable the implement attachment part to move freely past said arm and/or its pivotal fastening. Solution The present invention takes as its starting point an arrangement which will enable an implement attachment part to be held securely to the free end of a crane arm in a parking position, wherein said implement attachment part is pivotally fastened to said free end via at least one pivot shaft, wherein said implement attachment part comprises at least two mutually rotatable parts, wherein said parts are adapted for rotation in relation to each other through the medium of a piston cylinder device. For the purpose of solving one or more of the aforesaid problems, it is proposed in accordance with the present invention that there is provided, between a first securing device associated with said implement attachment part and a sec- ond securing device associated with the crane arm, at least one tension-force take-up device, and that activation of said piston-cylinder device causes the implement attachment part to be brought to a parking position beneath or above the crane arm. By way of embodiments that lie within the scope of the inventive concept, it is proposed that two tension-force take-up devices shall be used, a first for rotating the implement attachment part about a first pivot shaft, and a second for laterally orientating the implement attachment part about a second pivot shaft. It is also proposed that the length of the first device shall be shorter than the length of the second device. At least one of said devices may consist of a chain, and the lengths of respective devices may be mutually adjustable by means of a bottlescrew or corresponding means. It is also proposed in accordance with the invention that a first rotor unit, a first pivot shaft, a link, and a second pivot shaft that crosses the first pivot shaft at right angles, or some corresponding arrangement, is provided between the implement attachment part and the free end of said arm or dipper stick . It is also proposed that a generally U-shaped element shall be pivotally mounted on the free end of the arm or dipper stick and carry a holder that is adapted for co-action with said first pivot shaft. It is also proposed in accordance with the invention, that the pivotal attachment to the free end of the arm or dipper stick can be adjustable, so as to enable the position of the first pivot shaft to be adjusted. It is also proposed that a tension-force take-up device is fastened to a fixed part of the crane arm or the dipper stick, and that a further tension-force take- up device may be attached to an extension of said generally U-shaped element with said element facing towards the fixed part of the crane arm. In particular, the invention proposes that the arrangement is applied to a crane-arm arrangement that has an arm pivotally mounted at both ends and a dip- per stick which is fastened to one end of said arm and positioned in the close proximity of said arm but in a vertical plane that is orientated laterally of the vertical plane of said arm, and in which the implement attachment part is rotated laterally in relation to a parking position so as to be able to move freely past said arm and/or its pivotal attachment and into said parking position. Advantages Those advantages that can be considered to be primarily characteristic of an inventive arrangement reside in the creation of conditions for moving and folding a crane-arm arrangement of known kind into a parking position, wherewith the free, dipper stick -associated end of the crane-arm arrangement can securely hold an implement attachment part in said parking position, even an attachment part of a more complex kind, namely an attachment part that consists of at least two parts that can be rotated relative to each other, and wherewith the parts, by means of a piston-cylinder device, are adapted for rotation in relation to each other, and wherein, inter alia, a rotor unit, a first pivot shaft, a link and a second pivot shaft can be provided between the implement attachment part and the free end of said arm. By laterally displacing or laterally rotating the implement attachment part, said part is able to move past a pivotal connection between the free end-part of a crane arm and the pivotal attachment of the dipper stick to said free end-part of the crane arm. The primary characteristic features of an arrangement for securing an implement attachment part to the free end of a crane arm or dipper stick in a parking position are set forth in the characterising clause of the accompanying claim 1. Brief description of the drawings An arrangement at present proposed and having characteristic features significant of the invention and illustrating the construction of said arrangement and its application will now be described by way of example with reference to the accompanying drawings, in which Figure 1 is a perspective view of a truck seen obliquely from the rear and equipped with a crane-arm arrangement and with an implement attachment part mounted in accordance with the invention; Figure 2 is a side view illustrating the free end of a crane arm or a dipper stick to which the implement attachment part is pivotally mounted, and shows a tension-force take-up device connecting the free end of the crane arm to the implement attachment part, distanced from a parking position; Figure 3 is a side view which shows the implement attachment part in a position beneath and adjacent to the free end of the crane arm or dipper stick , and also shows a piston-cylinder device associated with the implement attachment part and activated to initiate tensile forces in the tension-force take-up device; Figure 4 is a plan view illustrating the side-related position taken by the arrangement shown in fig. 3; Figure 5 is a side view of the arrangement in an upper locked position; and Figure 6 is a slightly enlarged view of part of fig. 5. Description of embodiments at present preferred Figure 1 is a perspective view of a truck 1 on which a crane-arm arrangement 2 is mounted. Connected to the free end of the arrangement 2 is one part 3 of a two-part implement attachment of the kind illustrated in fig. 12 of the interna- tional patent application mentioned in the introduction. Provided in the truck 1 between the driver's cabin 1a and the loading platform 1 b of the truck is a space 1c within which the crane-arm arrangement 2 is able to take a parking position. The contents of said international patent application shall be included as part of the present patent application. The crane-arm arrangement 2 comprises a vertical pillar 2a which is mounted in means (not shown) for rotation about a vertical axis 2a' and which carries, via a horizontal pivot shaft 2b', an arm 2c which, via a pivot shaft 2d', co-acts with a dipper stick 2e which supports said part 3 of the implement attachment or said part 3 of the implement holder at its free end 2f, through the medium of known means. It will be seen from fig. 1 that the arm 2c is positioned in a first vertical plane V1 while the dipper stick 2e is positioned in a second vertical plane V2, in which the arm 2c and the dipper stick 2e can lie in close proximity to each other. Because the implement attachment part 3 is comprised of a complex unit, it is necessary that said part is able to move past the pivot shaft 2b' so that it can be folded from an extended position to a fully collapsed position, a so-called parking position. This will be described in more detail below. It will be seen from fig. 2 that the free end 2f of the dipper stick 2e, consist- ing of several telescopic arms, securely holds the implement attachment part 3, and that a device 4 that functions to take-up tensile forces is connected between the attachment part 3 and a fastening means 5. The inventive arrangement is adapted for rotation of the crane-arm arrangement 2 from a fully extended position to a parking position with the imple- ment attachment part 3 mounted on the arrangement, while said part 3 remains attached to the free end 2f of the crane arm or the dipper stick . The implement attachment part 3 is rotatably mounted to said free end 2f, through the medium of at least one pivot shaft (6a or 6b). The implement attachment part 3 is comprised of at least two mutually ro- tatable parts 3a, 3b, wherein, although not shown, the parts 3a, 3b are adapted for rotation relative to one another from the position shown in fig. 2 to the position shown in fig. 3, by means of a piston-cylinder device 7 not specifically shown. This is illustrated and described in more detail in the aforesaid interna- tional patent application and will not therefore be described in detail in this document. The inventive arrangement includes at least one device 4 which functions to take up tensile forces and which extends between a securing device 10 on the implement attachment part 3 and a securing device 1 1 on the crane arm 2. Activation of the piston-cylinder device 7 will cause the implement attachment part 3 to be moved to a lifted parking position (see fig. 3) beneath the crane arm and/or the dipper stick . More particularly, the invention includes the use of two tension-force take- up devices 4a, 4b that have a common point of attachment to the securing device 10 and respective fastening points 11a, 1 1 b each being related to the free end 2f of the crane arm arrangement with a first fastening point 1 1a centrally orientated and a second attachment point 1 1 b being laterally orientated. A tension-force take-up device 4b is adapted to rotate the implement attachment part 3 about a pivot shaft 6a up towards the dipper stick 2e, while a sec- ond tension-force take-up device 4a is adapted to be able to laterally orientate or laterally rotate the implement attachment device 3 about another pivot shaft 6b. It will be noted that these pivot shafts 6a and 6b are orientated at right angles to each other in their respective mutually parallel planes. The length of at least one of said tension-force take-up devices, preferably the effective length of the first device 4a, is shorter than the effective length of the other device, preferably the second device 4b. These devices 4a, 4b may conveniently consist of one or more chains and the lengths of one or both chains may be adjustable with the aid of a bottlescrew or corresponding means. The complexity of the implement attachment part 3 lies, inter alia, in the inclusion between the part 3 and the free end 2f of the arm 2e of an hydraulically rotatable rotor unit 20, a pivot shaft 6b, a link 21 , a second pivot shaft 6a, and a generally U-shaped element 30 mounted on said free end 2f. The U-shaped element 30 is conveniently pivotally mounted on the free end 2f of the arm 2e and carries a holder 31 for the first pivot shaft 6a. The pivotal attachment 6a enables the part 3 to be swung to a position that lies closer to or further from that part of the crane arm that is adjacent its free end. The first tension-force take-up device 4a is attached to a fixed part of the crane arm and the second tension-force take-up device 4b is attached to an extension of the U-shaped element 30 in a direction towards said fixed part of the crane arm. The invention therewith provides an arrangement which can be applied to a crane arm arrangement which has an arm 2c that is pivotally mounted at both ends and a dipper stick 2e which is mounted on one end of the arm in the close proximity of but in a vertical plane V2 that is orientated laterally of the vertical plane V1 of said arm. According to the invention, when parked the implement attachment part 3 shall have been so rotated laterally as to have freely moved past said arm and/or its pivotal fastening 2b' and can thus be enclosed in a space that is exposed by the crane arm construction when this is located in a parking position. Figures 5 and 6 illustrate how an implement attachment 3 can be rotated to a position above the dipper stick 2e with the aid of the tension-force take-up de- vices 4a, 4b. It will be understood that the invention is not restricted to the aforede- scribed exemplifying embodiment thereof and that modifications can be made within the scope of the inventive concept illustrated in the accompanying claims.

Claims: CLAIMS 1. An arrangement for securing a part of an implement attachment to a free end of a crane arm, in a parking position, wherein the implement attachment part is pivotally mounted to said free end through the medium of at least one pivot shaft, wherein said implement attachment part comprises at least two parts that can be rotated relative to each other, and wherein said parts can be rotated relative to each other through the medium of a piston-cylinder device, characterized in that at least one tension-force take-up device is provided between a securing device associated with said implement attachment part and a securing device associated with said crane arm; and in that activation of said piston-cylinder device can bring the implement attachment part to a parking position beneath or above the crane arm. 2. An arrangement according to claim 1 , characterized in that the arrangement includes two tension-force take-up devices, of which a first allows rotation of the implement attachment part about a first pivot shaft and a second permits the implement attachment to be orientated laterally about a second pivot shaft. 3. An arrangement according to claim 2, characterized in that the effective length of one of said devices is shorter than the effective length of the other device. 4. An arrangement according to claim 1 or 2, characterized in that at least one of said tension-force take-up devices is a chain. 5. An arrangement according to claim 1 or 2, characterized in that the lengt of the tension-force take-up device can be adjusted through the medium of a bot- tlescrew or corresponding means. 6. An arrangement according to claim 2, characterized in that at least one rotor unit, a first pivot shaft, a link, and a second pivot shaft are mounted between Ifce implement attachment part and the free end of said arm. 7. An arrangement according to claim 1 , characterized by a generally U- shaped element pivotally attached on the free end of the arm and carrying a pivot shaft holder. 8. An arrangement according to claim 7, characterized in that the pivotal at- tachment can be adjusted. 9. An arrangement according to claim 1 or claim 7, characterized in that a first tension-force take-up device is attached to a part of the crane arm, and in that a second tension-force take-up device is attached to an extension of said U- shaped element that faces towards the fixed part of the crane arm. 10. An arrangement according to claim 1 , when applied to a crane arm arrangement that has an arm pivotally mounted at both ends and a dipper stick which is attached to one end of the arm and which is positioned in the close prox- imity of said arm but in a vertical plane that is orientated laterally of the vertical plane of said arm, characterized in that in a parking position the implement attachment part is orientated laterally as to move freely past said arm and/or its pivotal attachment.

Inventors: HAMMARSTRAND OVE, HAMMARSTRAND, OVE
Applicants: HAMMARSTRAND OVE, HEVO PARTS AB, HAMMARSTRAND, OVE, HEVO-PARTS AB
Application year: 2001
Main classification: B66C3
IPC codes: B66C23