A DEVICE IN TELESCOPIC ARMS

Abstract: In a telescopic arm device having three arm parts (4, 5, 6), flexible hydraulic hoses (12) extend between connection places (13, 14) on a base arm part (4) and the outermost (5) of the arm parts. The lines are between these connection places arranged in a bight (15), from which the lines run in generally the same direction to the connection places (13, 14). Between the bight (15) and the connection place (14) on the outer arm part, the lines run in tubes secured to the second and third parts (5, 6), said tubes co-operating telescopingly so as to guide the lines to extend in a generally straight path between the bight (15) and the connection place (14) on the outer arm part (5).

Description: A device in telescopic arms FIELD OF INVENTION AND PRIOR ART The present invention is related to a device in telescopi arms, in particular telescopic arms intended for cranes, according to the preamble of enclosed claims 1 and 8. The power supply lines are preferably formed by pressure fluid lines, for example hydraulic hoses, intended to serve for power supply to a load handling apparatus pro¬ vided on the arm part which is located outermost in the extended state of the telescopic arm. However, it is to be understood that also other types of power supply lines may be in question, e.g. electric lines. Such a device is disclosed in the French patent specifi¬ cation 2 287 411. In this known device, the hydraulic lines are located internally within the space commonly formed by the arm parts, a fact which in certain cases may involve a considerable disadvantage since the internal arrangement of the lines makes it impossible to provide a further telescopically extendable elongation part within the arm part, which is located outermost in the extended state of the telescopic arm. Further, in the device according to the French patent specification the bight-like diversion of the hydraulic lines is defined by means of a diverting member in the form of a wheel located within the intermediate part. The diverting member acts on the hydraulic lines on con¬ traction of the telescopic arm so that the lines are pulled back. In certain cases it is disadvantageous to have to use such internally located diverting members since they increase the cost and are difficult to get access to for service and replacement. SUMMARY OF THE INVENTION The present invention aims at reducing disadvantages men¬ tioned hereinabove and thus present construction solu¬ tions, by means of which the lines may be located exter¬ nally in the sense that the interior of the arm part lo¬ cated outermost in the extended state of the telescopic arm is available for arranging a further elongation part extendable from this outermost arm part or by means of which the device generally speaking may be simplified so that there is no longer need for any diverting members in the form of wheels or the like for the lines, which thus then are intended to run JLn a bight-like free diver¬ sion. These aims are met by the present invention by the constru tional features more closley defined in the characterizing portions of the enclosed claims . BRIEF DESCRIPTION OF THE DRAWINGS With reference to the enclosed drawings, a more specific disclosure of embodiment examples of the invention follows hereinbelow. In the drawings: fig 1 is a perspective view of a telescopic arm device according to the invention, fig 2 is a partly cut side view of a telescopic arm device in contracted state, fig 3 is likewise a partly cut side view of the telescopi arm device, illustrated, however, in extended state, fig 4 is a cross section taken along the line IV-IV in fig 2, the telescopic arm proper being diagrammatically illustrated in fig 4, fig 5 is a partly cut side view similar to fig 2 but illustrating an alternative embodiment in contracted stat and fig 6 is a view similar to fig 5 but illustrating the telescopic arm in extended state. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The embodiment according to figs 1-4 will now initially be more closely described. The telescopic arm 1 illustra¬ ted therein is intended to be comprised in a load crane. The arm 1 is preferably intended to be pivotably arran¬ ged about a normally generally horizontal axis relative to a further arm 2 contained in the crane. A power member 3, e.g. in the form of a hydraulic cylinder, acting bet¬ ween arms 1 and 2 may serve for controlling said pivota- bility. The arm 1 comprises in the embodiment three arm parts mutually movable by means of a power arrangement, namely a first base arm part 4 and two second and third arm parts 5 and 6 respectively extendable therefrom. The arm part 6 receives in an internal space therein the arm part 5 whereas arm part 6 itself is adapted to be received in an internal space in arm part 4. Thus, arm parts 4-6 are formed by hollow beams. The power arrangement for obtaining the mutual mobility between arm parts 4-6 comprises in the embodiment a power member 1 , e.g. a hydraulic cylinder, variable in length and acting between an attachment 8 relative to arm part 4 and an attachment 9 relative to arm part 6. Thus, arm part 6 will on extension and contraction of power member 7- be pushed out of respectively drawn into arm part 4. Further, the power arrangement comprises means for ob¬ taining, on movement of arm part 6 relative to arm part 4, an equally great and unidirectional movement between arm parts 5 and 6. As an example it may be mentioned that the power arrangement advantageously may be designed in accordance with our Swedish patent 8403618-5 (442 985), according to which the movement of arm part 5 relative to arm part 6 is effected by means of flexible traction force transmitting members, e.g. chains. With other words, arm part 5 will on extension and contraction respectively of arm 1 move relative to arm part 4 in the_ same direction as arm part 6 moves relative to arm part 4 but with double velocity. The outer arm part 5 comprises at its extreme end means 10 for attaching load carrying apparatus of various nature. The load carrying apparatus is in the embodiment intended to consist of a load gripping apparatus comprising a ro¬ tator 11 for rotating the gripping apparatus about a ge¬ nerally vertical axis. The gripping apparatus is not illus rated in fig 1 but is intended to be connected to the lower side of rotator 11. Power supply lines 12, in the embodiment four in number, extend between fixed connection places 13 and 14 on arm parts 4 and 5 respectively (see in particular fig 2). The lines 12 are at least along a portion of their length flexible and arranged in a bight-like diversion 15, from which the lines run to the respective connection places 13 and 14 on arm parts 4 and 5 respectively in generally the same direction along the longitudinal extent of arm 1, i.e. towards the extreme ends of arm parts 4 and 5 located to the left in fig 2. As appears when comparing figs 2 and 3, the bight-like diversion 15 is adapted to be displaced along arm part 1 on extension and contrac¬ tion of the telescopic arm 1. The lines 12 should be flexi ble at least along such a length that this displacement of the diversion location 15 is allowed. The lines 12 are in the embodiment formed by hoses, in particular hydra lic hoses, which present flexibility along the entire extent between the connection places 13 and 14. The arm comprises an arrangement guiding the lines and generally denoted 16, said arrangement comprising first guide means 17 connected to arm part 6. This guide means 17 is located externally of the internal space of arm part 6 adapted for receiving arm part 5 and defines a guiding passage 18 for the lines 12 along part 6 and bet¬ ween bight 15 of the lines and their connection place 14 to arm part 5. The guiding arrangement 16 comprises furthermore second guide means 19 attached to arm part 5, said guide means defining a guiding passage 20 for lines 12 and co-operatin in a telescoping manner with first guide means 17 so that first and second guide means 17 and 19 on contrac¬ tion of telescopic arm 1 will force lines 12 and there by bight 15 to be displaced rearwardly in direction to the right in fig 3. The portion of lines 12 being displace is accordingly bight 15 and the line portions between the latter and connection place 14, whereas the line por¬ tions between bight 15 and connection place 13 will not be displaced. The first guide means has the character of a tubular member 17, which as appears from fig -4 has a rectangular cross section and which at its one end comprises an attachment 21, by means of which tube 17 is secured to an attach¬ ment 22 provided on the extreme end of arm part 6. The connection between attachments 21 and 22 may be formed by a pivot pin 23. Tube 17 projects into a space 24 in connection with arm part 1. Locating members 25, e.g. in the form of slide pads, may be provided within space 24 and locate in conjunction with pivot pin 23 the tube 17 in a . position along arm 1. Also the second guide means 19 is formed by a tubular member having a rectangular cross section and being at one of its ends secured to the extreme end of arm part 5. More specifically, tube 19 comprises an attachment 26, by means of which tube 19 is secured to an attachment 27 on arm part 5 through a suitable connection 28, e.g. in the form of a pivot pin. The connection place 14 of lines 12 is in the embodi¬ ment formed at the attachment 26 so that lines 12 thereat are secured such that lines 12 on extension of arm 1 will be pulled out starting from connection place 14 during simultaneous displacement of bight 15 to the left in fig 2. At connection place 14 there are in the embodiment arranged coupling nipples or the like (fig 2), to which lines 12 adjoin and to which flexible line sections 29 (fig 1 ) may be secured. The latter form a transition to the gripping apparatus; the four lines in the embodiment may more specifically be used so that two of them form hydraulic supply and return respectively for rotator 11 whereas the two other lines form hydraulic supply and return respectively for a power member contained in the gripping apparatus for operating arms or the like therein. The number of lines 12 may of course vary from 1 and higher as appears in fig 4 it is suitable, if four lines 12 are in question, to arrange them in rectangular distribution within the rectangular tubes 17 and 19. Tube 19 extends exteriorly of the internal space of arm part 5 and has a smaller cross section than the internal cross section of tube 17 so that tube 19 may enter into tube 17 in the manner illustrated in the drawings. It may be suitable to arrange slide pads or the like between the external surface of tube 19 and the internal surface of tube 17. The space 24 is in the embodiment formed exteriorly of arm part 4. More specifically, a housing generally de¬ noted 30 may as appears from fig 4 be arranged on one side of arm part 4, said housing comprising a body part 31 having a plate formed base portion 32 laid against arm part 4 and two mutually spaced shanks 33 projecting away from the plate portion 32 in a direction away from arm part 4. Further, housing 30 comprises in the embodi¬ ment a cover 34, which may be put on shanks 33 and secure thereto be means of diagrammatically indicated securing means so that body part 31 and cover 34 jointly form space 24, which extends along arm part 4. Housing 30 may be open at its ends in a manner appearing from figs 1 and 2. As an alternative to housing 30 illustrated it would be conceivable to design space 24 as a chamber located within arm part 4 but entirely or partly separated from the in¬ ternal space of arm part 4 which telescopingly receives arm part 6. From that stated it appears that tube 17 in the embodiment extends exteriorly of the interior space in arm part 4 receiving arm part 6. It is essential that lines 12 at connection place 13, which here is located within space 24, are secured in such way that the connection place 13 is not displaced relative to arm part 4 when telescopic arm 1 is extended and contracted. In the embodiment the flexible lines 12 transform at connection place 13 into rigid line sections 35 secured relative to housing 30 and thereby relative to arm part 4. These rigid line sections 35 transform at a coupling location 36 into flexible hoses 37, which extend out of the interior of housing 30 through an ope¬ ning and then are drawn, in a manner not illustrated in detail, towards crane arm 2 along arm part 4 and pass over to crane arm 2 via a loop or in other arbitrary manne It is to be understood that although there are in the embodiment also line couplings at connection places 13 and 14, such line couplings are no necessity. Thus, it is only intended with the expression "connection places" that the lines are so firmly connected relative to respec¬ tive arm parts 4 and 5 that the hose guiding described and desired is obtained. As appears from fig 2, the bight 15 and the rear end of the guide tube will protrude somewhat out from the interna space 24 of housing 30 when telescopic arm 1 is contracted this is due to the fact that in the embodiment chosen housing 30 cannot be allowed to extend further rearwardly along arm part 4 but in other embodiments it may be suitab to design housing 30 so that bight 15 always is located within space 24 of the housing. However, bight 15 will also in the embodiment described generally be located within housing 30. From the description hereinabove it appears that bight 15 extends freely without particular diverting members. At one end of the bight the lines obtain support of the adjacent end of tube 17, whereas the lines near the other end of the bight obtain support of the shank 33 of hou¬ sing 30. On extension of telescopic arm 1 tractive forces are at connection place 14 applied on lines 12 such that these are pulled out simultaneously with and with the same pace as the arm parts 5 and 6 are pushed out. On contraction;of telescopic arm, tubes 17 and 19 will act as guides hin¬ dering lines 12 to deviate within tubes 17 and 19 from a generally rectilinear path, whereby the compressive force on the lines exerted at connection place 14 will cause the lines to be displaced within tube 17 rearwardly so that simultaneously the bight 15 is displaced rear¬ wardly. The embodiment described involves the advantage that the hose guiding device is readily accessible for service, maintenance and replacement by the exterior location of components exteriorly of the internal cavities of arm parts 4-6, and thereby the outer part 5 is ' interiorly free to receive a further telescoping elongation part. In cases where no such further telescoping elongation part is required and where an exterior arrangement of the hose guiding components is not suitable, it is to be understood that the telescoping tubes 17 and 19, hoses 12 and accordingly bight 15 could be located internally in the cavity formed by arm parts 4-6 in the manner occur¬ ring in the French patent specification 2 287 411. In that case it is suitable to arrange the attachment 21 of tube 17 in the area of the rear end of arm part 6. An alternative embodiment of the invention is illustrated in figs 5 and 6. With exception for what will be described hereinafter, the embodiment according to figs 5 and 6 corresponds entirely with the embodiment previously de¬ scribed, for what reason like characters are used for analogous parts in figs 5 and 6 only with addition of an "a". The guiding arrangement 16a for the lines comprises in the embodiment according to figs 5 and 6 also a diver¬ ting member 38, e.g. a wheel, about which the bight-like diversion 15a of the lines is formed and which is arranged to pull back lines 12a through tube 17a when the telescopi arm is contracted in a manner known per se by the French patent specification 2 287 411. Diverting member 38 is via a suitable attachment 39 secured to the rear end of tube 17a, i.e. the end of the tube which is turned away from the extreme end of arm part 6. Since diverting member 38 in this embodiment displaces bight 15a rearwardly on contraction of telescopic arm 1a and accordingly pulls back the hoses through tube 17a, tube 19 illustrated in the embodiment according to figs 1-4 may, as appears from figs 5 and 6, be deleted and accordingly the hoses may run freely between connection place 14a and the adjacent end of tube 17a. However, tube 19 may also be used in the embodiment according to figs 5 and 6 and then prima¬ rily to give protection for lines 12a along the entire extent of arm parts 5a and 6a.'The embodiment according to figs 5 and 6 may be suitable in cases where ' the consti¬ tution of lines 12a causes problems in achieving such pushing movement backwards of the lines which is aimed at in the embodiment according to figs 1-4. The embodiments described may of course be modified in several ways within the scope of the invention.

Claims: Claims 1. A device in telescopic arms, in particular telescopic arms intended for cranes, of the kind comprising at least three by means of a power arrangement mutually movable arm parts, namely a first base arm part (4, 4a) and at least two second and third arm parts (5, 6; 5a, 6a) exten dable therefrom, one or more power supply lines (12, 12a) extending between connection places (13, 14; 13a, 14a) on the first base arm part and the second arm part, said first and second arm parts (4, 5, 4a, 5a) being the mostl remote when the telescopic arm is extended, and being at least in part flexible between these connection places and arranged in a bight-like diversion (15, 15a), from which the lines run to the respective connection places on the first and second arm parts in generally one direc--. tion of the longitudinal extent of the telescopic arm and which is adapted to be displaced along the first arm part on extension and contraction of the telescopic arm, the device comprising an arrangement (16; 16a) guiding the lines and comprising first guide means (17, 17a) con¬ nected to the third arm part (6; 6a), which has the cha¬ racter of intermediate part, c h a r a c t e r i z e d by said first guide means (17 , 17a) being located exter¬ nally of the internal space of the third arm part (6, 6a) intended for receiving the second arm part (5; 5a), said guide means defining a guiding passage (18)- for the lines along the third part and between the bight-like diversion and the connection place (14, 14a) of the lines to the second part, and by a) either second guide means (19) being attached to the outer second part (5) and defining a guiding passage (20) for the lines and co-operating in a telescopic manner with said first guide means (17) so that the first and second guide means on contraction of the telescopic arm will force the lines and accordingly the bight-like di¬ version (15) to be pushed back, b) or said first guide means (17a) carrying at least one diverting member (38), about which the bight-like diver¬ sion (15a) of the lines is formed and which is adapted to pull back the lines in a manner known per se on contrac¬ tion of the telescopic arm. 2. Device according to claim 1, c h a r a c t e r i z e d in that said first guide means (17; 17a) projects into a space (24) in connection with the first arm part (4) and the bight-like diversion (15, 15a) of the lines is likewise receivable in said space. - 3. A device according to claim 2, c h a r a c t e r i ¬ z e d -in that said space (24) is formed externally of the first arm part (4). 4. A device according to any preceding claim, c h a r a c t e r i z e d in that said first guide means (17; 17a) comprises a tubular member, which at one of its ends is attached to the extreme end of the third arm part (6, 6a) . 5. A device according to claim 4, c h a r a c t e r i ¬ z e d in that said second guide means (19) comprises a tubular member, which at one of its ends is attached to the ' extreme end of the second arm part (5). 6. A device according to claims 1 and 4, c h a r a c t e r i z e d in that the diverting member (38) is arranged at the second end of said first guide means ( 17a) . 7. A device according to claims 2 and 6, c h a r a c t e r i z e d in that the diverting member (38) is receivable in the space (24a) associated to the first arm part (4a). 8. A device in telescopic arms, in particular telescopic arms intended for cranes, of the kind comprising at least three by means of a power arrangement mutually movable arm- parts, namely a first base arm part (4) and at least two second and third arm parts (5, 6) extendable there¬ from, one or more power supply lines (12) extending bet¬ ween connection places (13, 14) on the first base arm part and the second arm part, said first and second arm parts (4, 5) being the mostly remote when the telescopic arm is extended, and being at least in part flexible betwe these connection places and arranged in a bight-like di¬ version (15), from which the lines run to the respective connection places (13, 14) on the first and second arm parts in generally one direction of the longitudinal exten of the telescopic arm and which is adapted to be displaced along the first arm part (4) on extension and contraction of the telescopic arm, the device comprising an arrange¬ ment (16) guiding the lines and comprising first guide means (17) connected to the third arm part (6), which has the character of intermediate part, c h a r a c t e r i z e d by said first guide means (17) defining a guiding passage (18) for the lines (12) along the third part (6) and between the bight-like diversion (15) and the connection place (14) of the lines to the second part (5), and by second guide means (19) attached to the outer second part (5), said second guide means defining a guiding passage (20) for the lines and co-ope¬ rating in a telescoping manner with said first guide means (17) so that the first and second guide means (17, 19) on contraction of the telescopic arm will force the lines and thereby the bight-like diversion (15) to be pushed back. 9. A device according to any preceding claim, c h a r a c t e r i z e d in that the power arrangement is adapted to simultaneously and with the same velocity and direction displace the first and third as well as the second and third arm parts relative to each other. 10. A device according to any preceding claim, c h a r a c t e r i z e d in that the power supply lines (12; 12a) comprise hydraulic hoses for a hydraulic appa¬ ratus arranged at the extreme end of the second arm part (5, 5a)/ .

Inventors: GUSTAFSSON PAUL, GUSTAFSSON, PAUL
Applicants: TICO AB, AB TICO
Application year: 1988
Main classification: B66C13
IPC codes: B66C13