Device for interconnecting two jib arms relatively displaceable and fixable in a plurality of positions

Abstract

 @ A device for interconnecting the arms (1,2) of a jib of a machine such as an excavator, a crane or the like, said arms being relatively displaceable and fixable in a plurality of positions, whereby one of the arms is provided with coupling pieces (16,17) extending transversely of the direction of length of the arms and the other arm is provided with at least one clamping piece (23) having a part (30) gripping around a coupling piece, whilst one of the arms is furthermore provided with a slidable lock (24) with the aid of which a coupling piece and a clamping piece can be pressed one to the other.

Description

[0001] The invention relates to a device for interconnecting two arms of a jib of a machine such as an excavator, crane or the like, said arms being relatively displaceable and fixable in a plurality of positions.

[0002] In the prior art constructions it is common practice to provide the two arms with a plurality of equidistant holes disposed so that in a plurality of positions of the arms relative to one another the holes in the arms concerned are registering. For interconnecting the arms pins have to be passed through said holes. It is particularly difficult and time-consuming to cause the desired holes to register in such an accurate manner that the pins can be inserted into the holes concerned. Therefore frequently no attempts are made to arrange the arms into the relative positions desired for the operations to be carried out, which may result in undesirable loads of parts of the jib.

[0003] Apart therefrom mobile cranes involve the problem that when driving such a crane along the road the jib must not project too far in front of the frame of the vehicle. With regard thereto there is a need for the possibility of readily displacing the parts of the jib with respect to one another in order to dispose the front end of the jib nearer the vehicle proper during road transport. However, the construction hitherto used cannot satisfy these requirements.

[0004] The invention has for its object to provide a device by which the arms of the jib can be relatively displaced and be fixed in a plurality of relative positions in a simple manner.

[0005] According to the invention this can be achieved in that one of the arms is provided with coupling pieces extending transversely of the direction of length of the arm, whereas the other arm is provided with at least one clamping piece having a part gripping around the coupling pieces, whilst one of the arms is furthermore provided with a displaceable lock with the aid of which a coupling piece and a clamping piece can be pressed one against the other.

[0006] By applying the invention it is not necessary to ensure accurate registering of the holes in the arms before it is possible to pass pins through said holes, since it is only necessary to dispose a coupling piece and a clamping piece opposite one another, after which this coupling piece and the clamping piece can be clamped together with the aid of the lock in the desired position.

[0007] The invention will be described more fully hereinafter with reference to the embodiment of the construction in accordance with the invention schematically illustrated in the accompanying Figures.

Fig. 1 schematically shows part of an excavator, the arms of which' can be interconnected in known manner with the aid of pins.

Fig. 2 shows on an enlarged scale the ends of two arms interconnected by using the construction embodying the invention.

Fig. 3 is a side elevation of an end of one of the arms provided with coupling pieces and a clamping piece co-operating with the former and included in a part of the other arm not shown in Fig. 3.

Fig. 4 is a plan view of the arm of Fig. 3, the part of the other arm comprising the coupling pieces being also shown.

Fig. 5 schematically shows a hydraulic circuit.

Fig. 6 schematically shows a further embodiment of a construction in accordance with the invention.

[0008] Fig. 1 schematically shows a jib of an excavator comprising two arms 1 and 2 rigidly interconnected during operation and an arm 4 pivotally fastened with the aid of a pivotal shaft 3 to the end of the arm 2 remote from the arm 1.

[0009] The end of the arm 1 remote from the arm 2 is pivotally fastened with the aid of a pivotal shaft 5 to the superstructure 6 of the excavator shown only schematically. Such a superstructure 6 is usually rotatable about a vertical rotary axis and mounted on a vehicle (not shown).

[0010] The jib 2 can be turned about the pivotal shaft 5 with the aid of a setting cylinder 7 arranged between the superstructure 6 and the arm 1. In a similar manner the arm 4 can be turned about the pivotal shaft 3 with the aid of a setting cylinder 8 arranged between the arm 2 and the arm 3.

[0011] With the lower end of the arm 2 is coupled in a conventional manner a digging trough 9, which is pivotable about a pivotal shaft 10 with respect to the arm 4 by means of a setting cylinder 11 arranged between the digging trough 9 and the arm 4.

[0012] In the disposition shown in Fig. 1 the ends of the arms 1 and 2 are intercoupled with the aid of shafts 12 and 13, which are passed through holes provided for this purpose in the arms 1 and 2. From Fig. 1 it is apparent that the arm 2 has further holes 14 and 15, the various holes in the arm 2 being spaced apart by equal distances.

[0013] It will be obvious that after the removal of the pins 12 and 13 from the holes concerned in the arms 1 and 2 the arm 2 can be shifted with respect to the arm 1 into a different position in which the two arms can again be interconnected by inserting the pins 12 and 13 into again registering holes in the arms 1 and 2.

[0014] As stated above, this is a very troublesome and time-consuming operation.

[0015] According to the invention each side of the arm 2 is provided with four equidistant coupling pieces 16 to 19. Although in this embodiment four coupling pieces are provided,three coupling pieces may be sufficient or more than four coupling pieces may be arranged in dependence on the number of desired positions of the arms 1 and 2 relative to one another. The two coupling pieces, for example, the two coupling pieces 16 located one on each side of the arm 2 at the same level are preferably formed by a solid metal beam extending transversely across the end concerned of the arm 2.

[0016] Viewed from aside all coupling pieces 16 to 19 have the same sectional area and each of them has a ramp face or clamping face 20 being at an acute angle, in the embodiment shown an angle of about 45° to the longitudinal axis of the arm 2.

[0017] From Fig. 4 it will be apparent that the end of the arm directed towards the arm 1 is slidable in its direction of length and locked between two guide and fastening blocks 21 fastened to the top end of the arm 1. Each of the blocks 21 has a recess 22 (Fig. 2) to receive a clamping piece 23 as well as a lock 24. At the lower end the lock 4 is bifurcated and by this lower end it is coupled with the end of a piston rod 25 fastened to a piston of a setting cylinder 26.

[0018] From Fig. 2 it will be apparent that the boundary rim of the part of the clamping piece 23 accommodated in the recess 22 remote from the lock 24 as well as the opposite boundary wall of the recess 22 have a stepped shape so that, as shown in Fig. 2, the clamping piece 23 has, near its lower end, a projecting part 27 which grips below a projecting part 28 engaged in the recess 22 and belonging to the fastening and guide block 21. It will be obvious that in this construction the clamping piece 23 can slide to and fro to a limited extent in the direction of the arrow A in the recess 22, but cannot drop out of the recess. Only when the lock 24 is fully withdrawn from the recess 22, the clamping piece 23 can be removed from the recess.

[0019] In the position shown in Fig. 2 the top end of the lock projects above the fastening block 21 and is in engagement by a boundary wall with a boundary face of the coupling piece 17 extending parallel to the direction of length of the lock and at least substantially at right angles to the longitudinal axis of the arm 2. The opposite boundary face 29 of the lock 24 is at an acute angle to the longitudinal axis of the lock 24 and the longitudinal axis of the arm 2 and is in engagement with a boundary face of the clamping piece 23 locked opposite and parallel to said boundary face 29.

[0020] On the side remote from the lock 24 the clamping piece 23 has a projecting nose 30 which grips around the coupling piece 20 and which is in engagement by a boundary face 31 with the inclined face 20 of the coupling piece 16.

[0021] Furthermore each fastening block 21 is provided with a projecting nose 32 forming a further clamping piece and being, by a boundary face 33, in contact with the inclined boundary face 20 of the coupling piece 17.

[0022] From Fig. 2 it will furthermore be apparent that the faces 29 and 31 are upwardly inclined away from one another.

[0023] It will be obvious that by the upwardly pushed lock 24 the clamping piece 23 gripping around the coupling piece 20 is clamped against the latter, whereas on the other hand the coupling piece 17 is clamped below the clamping piece 32 gripping around said coupling piece.

[0024] In principle, the clamping pieces 23 could be rigidly arranged on the fastening blocks 21, but in this case the various parts have to be manufactured with very narrow tolerances. Since the clamping pieces 23 are movable within given limits in the direction of the arrow A with respect to the fastening blocks 21 the manufacturing tolerances are less stringent.

[0025] From Figs. 2 and 4 it is furthermore apparent that the ends of the fastening blocks 21 are provided with an at least substantially U-section guide member 33 for the rear end of the arm 2, said guide member 33 comprising two relatively parallel plates 34 fastened to the guide blocks 21 and a plate 35 interconnecting the rims of the plates 34 remote from the guide blocks 21.

[0026] During operation the pressure in the two setting cylinders 26 coupled with the locks 24 is maintained in order to prevent these locks24 from getting unintentionally loose during operation.

[0027] For this purpose the feeding circuit schematically shown in Fig. 5 is used for the setting cylinders.

[0028] The inlet duct 36 for the supply of pressurized fluid is connected with an inlet valve 37, which communicates through a non-return valve 38 with an accumulator 39. The inlet valve 37 is designed so that through this valve pressurized fluid is admitted only when the pressure in the accumulator 39 has dropped below a given value, the pressure in the accumulator 39 being then raised to a higher value than that at which the valve 37 opens. The inlet duct 36 is connected with the duct for the supply of pressurized fluid to one of the setting cylinders 7, 8 or 11 so that during operation the pressure in the accumulator 39 will always be automatically restored if it would drop below the desired value.

[0029] Through a safety valve 40 which prevents transgression of a given maximum pressure in the accumulator 39, the accumulator 39 is connected with a supply tank 41.

[0030] The accumulator 39 is furthermore directly connected through a duct 42 with the top ends of the setting cylinders 26 and through a magnetically operable valve 43 with the lower sides of the setting cylinders 26.In the position shown of the piston rods 25 and of the pistons 25' connected therewith, which position corresponds with the locking position shown in Fig. 2 of the lock 24 concerned, the pistons 25' and hence the piston rods 25 and the locks 24 coupled herewith will be held in the position shown, since the surfaces of the pistons 25' exposed to the fluid pressure and located on the sides of the pistons remote from the piston rods 25 are larger than those on the sides where the piston rods are fastened to the pistons.

[0031] When the valve 43 is changed over, the lower ends of the setting cylinders 26 come into open cummunication with the supply tank 41 so that the fluid can flow away from the lower ends of the cylinders 26 and the- pistons with the piston rods and the locks are moved downwards, as viewed in Fig. 5, by the pressure exerted on the top sides of the pistons. When returning the valve 43 into its normal, preferred position, pressurized fluid will again be fed to the lower ends of the setting cylinders 26 so that the locks are reset into the locked position.

[0032] For displacing the arm 2 with respect to the arm 1 first the locks 24 are withdrawn after the digging bucket 9 has been deposited on the bottom. The lower rim of the bucket 9 is then a fixed supporting point for the parts connected herewith so that, after the withdrawal of the locks 24 a small displacement of the arm 2 in its direction of length with respect to the arm 1 can be performed by some manipulation of the setting cylinders 7, 8 and 11 in a manner such that the noses 30 and 32 gripping around the coupling pieces 16 and 17 are set free of said coupling pieces. Subsequently with the aid of the setting cylinder 7 the arm 1 can be slightly turned in clockwise direction about the pivotal shaft 5, as viewed in Fig. 1, which results in a relative turn of the arm 2 with respect to the arm 1 in an anti-clockwise direction. Therefore, the arm 2 with the coupling pieces 16 to 19 fastened thereto can be moved relatively to the initial position into the position indicated by broken lines in Fig. 3. By subsequently sliding the arm 2 in its direction of length indicated by the arrow B, viewed in Fig. 3 by an appropriate manipulation of the said setting cylinders, it can be achieved that, for example, the coupling piece 17 moves over and across the clamping piece 23 to arrive at the position initially occupied by the coupling piece 16 in the position indicated by broken lines. If further displacement of the arm 1 is desired, the arm 2 can be slid to an extent such that the coupling piece 18 arrives at the position initially occupied by the coupling piece 16. Subsequently the aforesaid relative turns of the arms 1 and 2 relative to one another can be caused to take place in the reverse direction so that the arm 2 will again be in the position shown in Figs. 2 and 3, after which by actuating the locks 24 the clamping pieces 23 will grip, for example, around the coupling pieces 17 or 18 and the clamping pieces 32 around the coupling pieces 18 or 19 in the position in which the arm 2 is again clamped around the arm 1.

[0033] During this displacement of the arm 2 with respect to the arm 1 the guide member 33 prevents the end of the arm 2 from moving from between the fastening and guide blocks 22 and from getting free of the arm 1.

[0034] From the foregoing it will be apparent that by using the construction embodying the invention a firm connection between the two arms 1 and 2 of the jib can be ensured in a simple manner, whilst without appreciable exertion of force the two arms can be relatively displaced and fixed to one another in a plurality of positions by the operator of the excavator without requiring time-consuming aligning operations.

[0035] Although the construction is described above in conjunction with an excavator, it will be obvious that the invention can also be applied to other devices such as cranes or the like in which jibs or the like are used, which have a plurality of relatively adjustable parts.

[0036] As a matter of course, within the spirit and scope of the invention complements and/or modifications of the embodiments described above are possible.

[0037] Fig. 6 schematically shows a further potential embodiment of the construction in accordance with the invention.

[0038] Parts corresponding with parts shown in and described with reference to preceding Figures are designated by the same reference numerals as in said Figures.

[0039] In this construction a locking plate 44 is used which is provided in the embodiment shown with two projecting lugs or locks 45, each of them being capable of co-operating with a clamping piece 23.

[0040] With the aid of guide members (not shown), for example, lugs fastened to the locking plate and guided in a guide and fastening block 21, the locking plate 44 is guided so that it can only move up and down at right angles to its direction of length, that is to say, as viewed in Fig. 6, in a vertical direction. For displacing the locking plate 44 there is provided a setting plate 46 provided with ears 47 extending upwardly at an acute angle to the longitudinal axis of the plate and being located in identically shaped recesses 48 in the plate 44. The setting plate 46 can be displaced in its direction of length, that is to say, viewed in Fig. 6 in a horizontal direction with the aid of a setting cylinder (not shown).

[0041] It will be obvious that a displacement of the setting plate 46 in a horizontal direction will result in a displacement of the locking plate 44 in a vertical direction owing to the resultant displacement of the projecting ears 47 in the recesses 48. In this way, with the aid of the locks 45 the clamping pieces 23 can be pressed home or released respectively in the same manner as described above.

[0042] The advantage of the construction embodying the invention is that with the aid of a single setting cylinder a plurality of locks 45 actuating each a clamping piece can be simultaneously displaced.

[0043] The figures used in the claims are only meant to explain more clearly the intention of the invention and are not supposed to be any restriction concerning the interpretation of the invention.

Claims

1. A device for interconnecting two arms of a jib of a machine such as an axcavator, a crane or the like, said arms being relatively displaceable and fixable in a plurality of positions, characterized in that one of the arms is provided with coupling pieces extending transversely of the direction of length of the arms and the other arm is provided with at least one clamping piece having a part gripping around a coupling piece, whilst one of the arms is furthermore provided with a slidable lock with the aid of which a coupling piece and a clamping piece can be pressed one to the other.

₂. A device as claimed in Claim 1 characterized in that at least one clamping piece B movable reciprocatorily with respect to the arm concerned in the direction in which the clamping piece is moved relatively to the coupling pieces when clamping the clamping piece to the coupling piece.

3. A device as claimed in Claim 1 or 2 characterized in that the clamping piece is provided with a projecting nose which grips around a coupling piece.

4. A device as claimed in anyone of the preceding Claims characterized in that a clamping piece and a coupling piece have boundary faces which are in contact with one another in a position in which the two arms are fastened to one another and are at an angle to the direction in which the clamping piece and the coupling piece are relatively moving during the fixation of the arms to one another.

₅. A devise- as claimed in Claim 4 characterized in that the lock is displaceable in a direction transverse of the direction in which during the coupling operation the clamping piece and the coupling piece are relatively moving, whilst the lock is provided with a face being at an acute angle to its direction of displacement and co-operating with a boundary wall of a clamping piece, which face is inclined in an opposite sense to the co-operating faces of a clamping piece and a coupling piece.

6. A device as claimed in anyone of the preceding Claims characterized in that to one arm are fastened fastening blocks on both sides of the other arm, whilst at least one clamping piece is integral with such a fastening block, whereas a further clamping piece is accommodated in a slidable manner in a recess in said fastening block and one arm is provided on both sides with coupling pieces.

7. A device as claimed in Claim 6 characterized in that a slidable clamping piece and a lock are located in the same recess in a fastening block.

8. A device as claimed in Claim 7 characterized in that the clamping piece and the fastening block are provided with interengaging parts which prevent a displacement of the clamping piece with respect to the fastening block in a direction parallel to. the direction of displacement of the lock as long as the lock is located in t recess.

9. A device as claimed in anyone of the preceding Claims characterized in that the end of one arm is provided with a guide cap for guiding the other arm during the displacement of the two arms relative to one another.

10. A device as claimed in anyone of the preceding Claims characterized in that the coupling pieces are formed by the ends of solid beams extending across the arm concerned.

11. A device as claimed in anyone of the preceding Claims characterized in that a plurality of locks are carried by a single carrying member which is displaceable with the aid of a single setting member.

12. A device as claimed in Claim 11 characterized in that the carrying member is formed by a plate displaceable at right angles to its direction of length and provided with recesses inclined to the longitudinal axis of the plate in which ears are located which are fastened to the setting member which is displaceable parallel to the direction of length of the plate.

13. A device as claimed in anyone of the preceding Claims characterized in that the lock is displaceable with the aid of a setting cylinder which is maintained under pressure to hold the lock in its locking position.

14. A device as claimed in Claim 3 characterized in that in normal operation the setting cylinder is in open communication with an accumulator to which pressurized fluid is fed from the feed duct of a working cylinder on the jib, whilst between the accumulator and the feed duct a valve is arranged which opens when the pressure in the accumulator drops below a given value and which closes when the pressure in the accumulator has reached a given value.

Drawing