METHOD AND ARRANGEMENT RELATING TO A SWING DAMPER

Abstract: The invention relates to an arrangement and to a method related to a swing damper, particularly to a swing damper (1) for supporting a tool (5) that hangs from a crane arm (2) or some similar structure. The swing damper (1) includes an upper part (11), which is connected to the crane arm (2), and a lower part (12) that carries a work tool (5) or some similar device either directly or via a rotator (4) for instance. The upper part (11) and the lower part (12) are pivotally interconnected via a pivot joint (13), wherewith the swing damper (1) includes a brake arrangement (50) in the form of a male-female-cone arrangement. Either the upper part (11) or the lower part (12) carries two mutually opposing female cones (52, 53). The part that lacks the female cones carries two mutually opposing male cone parts (60, 61). The conical surfaces of the male cone parts and the female cones are in mutual contact in effecting a braking operation, and the conical surfaces of the male cone parts and the female cones also function as bearing surfaces between the upper part (11) and the lower part (12). An outer portion (64, 65) of the male cone parts (60, 61) functions to transfer load to that part which lacks said female cones (52, 53).

Description: METHOD AND ARRANGEMENT RELATING TO A SWING DAMPER The present invention relates to a swing damper arrangement according to the preamble of Claim 1. The invention also relates to a method. A swing damper is used in conjunction with supporting different types of tools suspended, for instance, from a crane arm or jib with the intention of effectively and reliably braking or damping the pendular movement/swinging movement that normally occurs when manoeuvring the crane arm in connection with carrying out different tasks, for instance. Swing dampers can be used in connection with all conceivable types of tools that are suspended from the tip of a crane arm, for instance in connection with forest harvesters, forwarders, forest processors, log cranes, excavating machines, special duty machines, etc. The swing damper may have both a single damping mode and a double damping mode, i.e. it can dampen/brake pendular movement in one or two pendulating/swinging planes. An object of the present invention is to provide a highly advantageous brake arrangement in a swing damper, and also to provide a highly advantageous braking method. These objects are achieved with an arrangement and a method that have the characteristic features set forth in respective accompanying Claims . Listed below are a number of advantages afforded by the invention. A swing damper that includes an inventive arrangement is very compact . There is obtained a smooth and uniform braking action with even wear on those parts of the brake arrangement that are prone to wear, and also a highly advantageous bearing from a load carrying aspect, among other things. The brake arrangement has a long useful life and long intervals between adjustments are possible. The brake arrangement can be readily serviced. A desired basic braking torque setting can be easily achieved and any subsequent adjustment necessary to the brake arrangement can also be carried out very readily. Inventive arrangements can be used in swing dampers of both single and double mode types. The inventive arrangement also has technical and economical advantages . The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawings, in which Fig. 1 is a perspective view of an inventive arrangement mounted on the tip of a crane arm and carrying a gripping tool; Fig. 2 is an exploded perspective view of a swing damper that includes an inventive arrangement; and Fig . 3 is a vertical section view of said arrangement . Fig. 1 shows an inventive swing damper 1 pivotally mounted on the tip of a crane arm 2 through the medium of a swing joint/bearing 3. The swing damper 1 carries at its lower end a rotator 4, which, in turn, carries a tool in the form of a gripper 5. The bearing 3 allows free pendulating movement/swinging movement about a shaft or axis 6 , and the rotator 4 of the illustrated embodiment is hydraulically operated and enables the gripper 5 to be rotated in the performance of its duties . The hydraulic hoses leading to the rotator and the gripper have been omitted for the sake of clarity. The swing damper 1 includes an upper part 11, which is freely pivotally connected to the crane arm 2 via the bearing 3. The swing damper 1 also includes a lower part 12, which carries the tool 5, for instance via the rotator 4. The upper part 11 includes an attachment lug 15, which co-acts with the bearing 3. The lower part 12 includes an attachment means 16 for the rotator 4 or for direct attachment of the tool 5. The upper part 11 and the lower part 12 of the swing damper are pivotally connected to one another via a swing joint/bearing 13, so as to be able to swing about a shaft/axis 14. The pivot shaft 14 is generally perpendicular to the pivot shaft 6. This contributes to the desired mobility of the tool 5. In order to enable the pendulating movement/swinging movement of the tool 5 as the crane arm is manoeuvred to be dampened relatively quickly, the swing damper 1 is provided with a brake arrangement 50 which enables said pendulating movement/swinging movement about the pivot shaft 14 to be braked in a desired manner. The brake arrangement 50 included in the swing damper 1 has the form of a male-female-cone arrangement, which is described in more detail hereinafter. In the illustrated embodiment, the upper part 11 carries a brake element 51 that includes two mutually facing female cones 52, 53. The brake element 51 also includes a longitudinally extending slot 54 and an internal, central ring groove 55. The brake element 51 is placed in a corresponding hole 56 in the upper part 11 and fixed thereto by means of a lock pin 57. The brake element 51 is thus non- rotatably connected to the top part 11. The lower part 12 carries two mutually facing male cone parts 60,61 which each have a conical portion 62,63 and a cylindrical portion 64,65. The one male cone part 60 is non- rotatably carried by an attachment lug 66 on the lower part 12 and the other male cone part 61 is non-rotatably carried by an attachment lug 67 on the lower part 12. The attachment lugs 66 and 67 have holes 68,69 which are in longitudinal sliding co-action with the cylindrical portion 64,65 of the male cone parts. Non-rotatable locking of said parts can be achieved by the abutment of slide shoulders 70,71 against anvil shoulders 72,73. The brake arrangement 50 includes a tightening or tensioning device 80 which functions to move the male cone parts 60,61 towards each other. The tightening/tensioning device 80 includes a screw 81 and a nut 82, said screw 81 is extending through a clearance hole 83,84 in the male cone parts 60,61. The tensioning device 80 has at its nut end a spring element 85 that is comprised of mutually opposing cup springs 86, as apparent from Fig. 3. When greater spring forces are desired, the cup springs 86 can be grouped in a manner different to that illustrated. The cup springs 86 are guided by a collared guide sleeve 87 and are mounted in a recess 88 in the male cone part 61. A pressure-operated power generating means 90 is provided in the male cone part 60. This power generator 90 is comprised of a hydraulic piston to which pressure medium is supplied through a delivery line 91, said medium entering through an axial gap 92 located between the hydraulic piston 90 and a recess 93 in the male cone part 60. The hydraulic piston 90 is held in place by the head 94 of the screw 81, as will be apparent from Fig. 3. The pressure medium is conveniently delivered through the medium of a duct system that communicates with the rotator. The male cone parts 60 and 61 are thus held together by means of the aforesaid screw-and-nut arrangement, said nut 82 being tightened so as to compress the spring element 85 to an extent at which an appropriate basic braking action is obtained. When necessary, the braking effect can be increased by pressure adjustment with the aid of hydraulic oil introduced through the axial gap 92 at the hydraulic piston 90, such as to press the male cone parts 60,61 towards each other and therewith decrease the gap 95 between the male cone parts in keeping with wear and the contact pressure between the conical surfaces of the male cones and the conical surfaces of the female cones will be increased to an extent corresponding to the desired braking effect. It will be noted that the conical surfaces of the male cone parts and the female cone parts also function as bearing surfaces between the upper part 11 and the lower part 12. The bearing 13 will thereby be very stable and the screw 81 is relieved of the necessity to take-up transversally acting forces. The bearing surfaces /brake surfaces may be oil lubricated if so desired. It will also be noted that the cylindrical portions 64,65 of the male cone parts are in load transferring engagement with the holes/openings 68,69 in the lower part 12. Thus, swing damping is achieved by virtue of two mutually opposing female cones 52,53 carried by said upper part 11 and by virtue of two mutually opposing male cone parts 60,61 carried by the lower part 12, wherewith the conical surfaces of the male cone parts and the female cone parts are in mutual contact to provide a braking effect and, at the same time, function as load-carrying bearing surfaces between the upper part 11 and the lower part 12. Braking is achieved by a compressive force effect between the male cone parts 60,61. This pressure force is achieved by means of mechanical devices and/or by means of pressure medium actuation. Slotted female cones provide a play-free bearing when the brake arrangement 50 is tensioned/activated. The slots 54 in the female cones coincide with the hole centre of the lock pin 57. A basic braking action is set by appropriate compression of the spring element 85. An additional braking effect is achieved by hydraulic actuation. The male cone parts 60,61 have several functions; they function as shaft bearings, brake elements, hydraulic cylinders and wear limiting means. With respect to the male cone parts, means which lock said parts against rotation and which prevent separation of said parts are provided. The centre screw 81 is not subjected to any transversally acting forces and the guide sleeve/spacer sleeve 87 limits the magnitude to which the spring is tensioned and minimises the risk of fatigue in the cup springs 86. In the case of a simpler embodiment, the hydraulic piston 90 may be omitted so that solely the force exerted by the spring element 85 will be utilised in generating a braking torque. In this respect, a spring element may be mounted within both of the male cone parts 60,61 if so desired. In a further embodiment, the spring elements are excluded and replaced by hydraulic piston means . It will be noted that many constructive options exist within the scope of the present invention. The design and construction of the spring elements may also vary widely within the scope of the invention. In the case of the illustrated embodiment, the female cones are carried by the upper part and the male cone parts by the lower part. Naturally, the inventive arrangement may be constructed such that the female cones are carried by the lower part and the male cone parts are carried by the top part. Although the swing damper of the illustrated embodiment is a single-type damper, it will be understood that inventive arrangements can be used in double-type swing dampers, wherein swinging of both the bearing 3 and the bearing 13 can be dampened by means of inventive arrangements. In an alternative embodiment, the lengths of the cylindrical portions 64,65 of the male cone parts 60,61 may be such that said portions extend into the end parts of the brake element 51 prior to the cylindrical portions 64,65 merging with the conical portions 62,63. In addition to its female cones 52,53, the brake element 51 also includes cylindrical end parts for receiving end sections of the cylindrical portions 64,65 of the male cone parts 60,61. In the case of this alternative embodiment, the inner surface of the brake element includes both a cylindrical and a conical section. It will be understood that described and illustrated components can be replaced with functionally equivalent components within the concept of the invention. The choice of materials used is, of course, also optional. It shall thus be understood that the invention is not restricted to the illustrated and described embodiments and that changes and modifications can be made within the scope of the accompanying Claims .

Claims: CLAIMS 1. An arrangement relating to a swing damper, particularly to a swing damper (1) for carrying a tool (5) that hangs from a crane arm (2) or a similar device, wherein the swing damper (1) includes an upper part (11) which is connected to the crane arm (2) , and a lower part (12) which carries a working tool (5) or a similar device either directly or through the medium of a rotator (4) for instance, wherein the upper part (11) and the lower part (12) are pivotally interconnected via a pivot joint (13), and wherein the swing damper (1) includes a brake arrangement (50) in the form of a male-female-cone arrangement, characterised in that either the upper part (11) or the lower part (12) carries two mutually opposing female cones (52,53); in that the part which lacks the female cones carries two mutually opposing male-cone parts (60,61); in that the conical surfaces of the male-cone parts and the female cones are mutually in contact when effecting a braking action; in that the conical surfaces of the male-cone parts and female cones also function as bearing surfaces between said upper part (11) and said lower part (12); and in that the male cone parts (60,61) have an outer portion (64,65) which is in load transfer engagement with openings (68,69) in that part that lacks said female cones (52,53). 2. An arrangement according to Claim 1, characterised in that said arrangement (50) includes a tensioning device (80) which is adapted to exert a braking torque generating force between the male cone parts (60,61) . 3. An arrangement according to Claim 2, characterised in that the tensioning device (80) includes a screw (81) and a nut (82) . 4. An arrangement according to Claim 2 or 3 , characterised in that the tensioning device (80) includes a spring element (85) and/or a pressure-medium manoeuvred force generator (90) that acts between the male cone parts (60,61). 5. An arrangement according to any one of Claims 1-4, characterised in that the male cone parts (60,61) are non- rotatably connected to either the lower part (11) or to the upper part (12) of said damper. 6. An arrangement according to any one of Claims 1-5, characterised in that a part (51) or parts carrying the female cones (52,53) is/are non-rotatably connected to the upper part (11) or to the lower part (12) of said damper. 7. An arrangement according to Claim 6 , characterised in that the female cone part or parts includes/include a longitudinally extending slot (54) . 8. An arrangement according to any one of Claims 1-7, characterised in that a radial gap is arranged between the tensioning device (80) and one in the male cone parts (60,61) arranged axial through-penetrating opening (83,84) for the tensioning device (80) so that the tensioning device (80) is only subjected to axially acting forces. 9. A method relating to a swing damper, particularly to a swing damper (1) for carrying a tool (5) that hangs from a crane arm (2) or a similar device, wherein the swing damper (1) includes an upper part (11), which is connected to the crane arm (2) and a lower part (12) which carries a working tool (5) or a similar device either directly or via a rotator (4) for instance, wherein the upper part (11) and the lower part (12) are pivotally interconnected via a pivot joint (13), and wherein the swing damper (1) includes a brake arrangement (50) in the form of a male-female-cone arrangement, characterised by generating a swing damping effect through the medium of two mutually opposing female cones (52,53) carried by either the upper part (11) or the lower part (12), wherein the part that lacks the female cones carries two mutually opposing male cone parts (60,61); causing the conical surfaces of the male cone parts and the female cones to contact each other to produce a braking/damping effect and causing the conical surfaces of the male cone parts and the female cones to function as load carrying bearing surfaces between the upper part (11) and the lower part (12) at the same time; and by causing an outer part (64,65) of the male cone parts (60,61) to transfer load to that part which lacks said female cones (52,53) . 10. A method according to Claim 9, characterised in that braking torque is obtained by force exertion between the male cone parts (60,61) . 11. A method according to Claim 10, characterised by exerting said force with the aid of mechanical means (85) and/or by pressure medium actuation. 12. A method according to any one of Claims 9-11, characterised by applying a friction influencing medium to the conical surfaces of the male cone parts (60,61) and the female cones (52,53). 13. The use of an arrangement according to any one of Claims 1-8, characterised in that the arrangement is used to dampen or brake swinging of a suspended object (5) .

Inventors: HARR JOAKIM, JONSSON ANDERS, JONSSON CHRISTER, HARR, JOAKIM, JONSSON, ANDERS, JONSSON, CHRISTER
Applicants: HARR JOAKIM, INDEXATOR AB, JONSSON ANDERS, JONSSON CHRISTER, HARR, JOAKIM, JONSSON, ANDERS, JONSSON, CHRISTER
Application year: 2000
Main classification: B66C3
IPC codes: B66C3, F16F7