The present invention relates to the field of lifting equipment as well as cranes and other lifting devices used for lifting and loading within the transportation industry, energy industry, process industry and manufacturing industry, and more particularly to a lifting device and a chain lubrication arrangement of a lifting device.

Lifting equipment and cranes are used in industry for different applications, such as loading and unloading within the transportation industry and bulk material and other material handling within the process and manufacturing industry as well as within the energy industry. A crane is generally defined as a machine for lifting and moving heavy objects by means of ropes or cables suspended from a movable arm. One of the most common crane types is a telescopic crane. Telescopic cranes are special type of jib cranes having a telescopic jib or boom. Telescopic cranes are also often referred to as loader cranes, articulating cranes or knuckle-boom cranes. A telescopic crane has typically a hydraulically-powered articulated arm having one or more of the arm sections telescopic. Other lifting devices are for example forklift stackers and other lifting machinery.

One typical example of a lifting device is a telescopic crane. Telescopic cranes are used in industry for different applications these including handling of bulk material, such as coal, mineral, scrap metal and other material within the process and manufacturing industry as well as within the energy industry. Telescopic cranes are also typically used within the transportation industry as loading and unloading material these including loading and unloading of timber, bulk material, scrap metal and other material. The telescopic crane may also be a mobile crane or a truck-mounted crane. A truck-mounted telescopic crane is often a crane in which the numerous telescopic arm sections may be folded into a small space when the crane is not in use. Within forestry telescopic cranes are used in e.g. timber trucks for loading and unloading of timber.

One typical example of a telescopic crane according to the prior art may be seen in US Patent document US 7,311,489 B2, which presents a telescopic crane having an extendable telescopic arm structure, in which the hydraulic hoses are fitted outside the telescopic end-side inner arm portion. Another typical example of a telescopic crane according to the prior art may be seen in US Patent document US 3,893,480. In US 3,893,480 the hydraulic hoses are fitted inside the articulated arm of the telescopic crane and a separate coaxial hydraulic conduit is fitted outside the telescopic end-side inner arm portion when said arm is extended. When the telescopic end-side inner arm of US 3,893,480 is retracted, the coaxial hydraulic conduit slides inside the articulated arm of the telescopic crane.

Some of the typical telescopic cranes according to the prior art are designed to have the hydraulic hoses and pipes fitted inside the articulated arm and the telescopic end-side inner arm portion of the telescopic crane. Two typical examples of this type of telescopic cranes according to the prior art may be seen in US Patent documents US 5,924,837 and US 6,530,742 B2. Although the hoses and pipes may be somewhat safe from external objects these types of hoses are difficult to maintain or adjust. In US Patent documents US 5,924,837 there is presented a chain leading inside the articulated arm of the telescopic crane and the associated chain deflection roller or an idler deflecting the chain inside said articulated arm. The lubrication of the chain inside the articulated arm of the telescopic crane is very problematic to arrange satisfactorily.

European Patent documents EP 1842823 B1 and EP 2135836 B1 show a telescopic crane according to the prior art where in the connections for the hydraulic hoses are fitted to a special mounting block arranged in the end region of the articulated arm and in the interior of the crane arm pipe conduits lead to connections fitted to said mounting block. The prior art telescopic cranes, where both the hydraulic pipe conduits and the hydraulic hoses are fitted inside the telescopic crane structure have some problems. As the hydraulic hoses are tight and confined fitted inside the telescopic crane structure the hoses may wear against the moving telescopic boom parts. Furthermore, the special mounting block of a telescopic crane according to the prior art is complex and expensive to manufacture. Also the changing of the slide shoe is very troublesome and subject to dirt as the pipes and the hoses need to be disconnected. Furthermore, the chain leading to inside the articulated arm is difficult to replace and cannot be easily tightened. In these patent documents there also is no good lubrication of the chain in the tight and cramped space inside the articulated arm of the telescopic crane.

In lifting devices such as in telescopic cranes the chain leading inside the lifting device such as chain leading inside the articulated arm of a telescopic crane is one of the key components subjected to wear and tear. A good and satisfactory lubrication arrangement for the chain leading inside the lifting device would ensure the proper function and lifetime of the chain.

In today's demanding environment, the manufacturers of lifting devices are constantly looking for improvements and cost savings in the lifting device manufacturing. Likewise, there is also a demand in the market for a new type of a lifting device and a chain lubrication arrangement of a lifting device which would improve the use of the lifting device and ease the lifting device maintenance process when compared to the current prior art solutions.

An object of the present invention is thus to provide a method and an apparatus for implementing the method so as to overcome the above problems and to alleviate the above disadvantages.

The objects of the invention are achieved by a lifting device, said lifting device comprising a chain element leading inside said lifting device and a chain deflection roller deflecting the chain element inside the lifting device and a lubrication nipple, which said lifting device further comprises lubrication channel arrangement leading the lubricant through a bearing arrangement to an outer surface of said chain deflection roller to provide lubrication for said chain element.

Preferably, said lifting device is a telescopic crane comprising an articulated arm and at least one extendable arm.

Furthermore, the objects of the invention are achieved by a chain lubrication arrangement of a lifting device, said lifting device comprising a chain element leading inside said lifting device and a chain deflection roller deflecting the chain element inside the lifting device and a lubrication nipple, which said chain lubrication arrangement of a lifting device comprises lubrication channel arrangement leading the lubricant through a bearing arrangement to an outer surface of said chain deflection roller to provide lubrication for said chain element.

Preferably, the lubrication channel arrangement comprises a lubricant channel and a lubrication chamber. Preferably, the lubrication channel arrangement comprises lubrication channels in the chain deflection roller leading the lubricant to the lubricant to said bearing arrangement.

Preferably, the bearing arrangement of the lubrication arrangement comprises a bushing bearing. More preferably, the bushing bearing of the lubrication arrangement comprises holes leading the lubricant towards an inner surface of said chain deflection roller. Preferably, said bushing bearing is fixed to the inner surface of the chain deflection roller. Preferably, said bushing bearing has a sliding surface of suitable sliding bearing material, such as e.g. bronze, sintered tin bronze, plastic, bearing plastic, composite, polytetrafluoroethylene or polyoxymethylene.

Alternatively, the bearing arrangement of the lubrication arrangement comprises two or more rolling bearings and a channel between said rolling bearings. More preferably, said channel between said rolling bearings leads the lubricant towards an inner surface of said chain deflection roller.

Preferably, the lubrication channel arrangement comprises one or more lubrication channels in the chain deflection roller leading the lubricant to the lubricant to the outer surface of said chain deflection roller to provide lubrication for said chain element. Preferably, said chain lubrication arrangement comprises distribution grooves to help the grease distribution to the one or more channels in said chain deflection roller.

Preferably, said chain element is a chain, wire, belt, cable, hydraulic hose or another suitable chain element for transferring power or energy. Preferably, said chain element is connected to a chain tensioner.

• Figure 1 shows one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention;
• Figure 2 shows a detail of a longitudinal sectional view of an articulated arm of one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention;
• Figure 3 shows a detail of a longitudinal view of an articulated arm of one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention;
• Figure 4 shows a detailed view of one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention.

In the following, the invention will be described in greater detail by means of preferred embodiments with reference to the accompanying drawings of Figures 1 to 4.

Figure 1 shows one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention. The telescopic boom arrangement of a telescopic crane according to the present invention comprises an articulated arm 1, an extendable crane-side outer arm 2 and a further extendable end-side inner arm 3. The telescopic boom arrangement of a telescopic crane further comprises hydraulic pipe conduits arranged on top of the articulated arm 1 of the telescopic crane, which hydraulic pipe conduits are at least partially covered with a cover. Furthermore, the articulated arm 1 of the telescopic boom arrangement of a telescopic crane has an opening for the hydraulic pipe conduits on the upper face of the articulated arm, which opening may be at least partially covered with a removable cover arranged at the arm region of the articulated arm 1. The telescopic boom arrangement of a telescopic crane according to the present invention also comprises a chain element 4 which extends from the articulated arm over a chain wheel arranged at the crane-side outer arm 2 leading inside the articulated arm 1 of the telescopic crane and the associated chain deflection roller or and idler deflecting the chain inside said articulated arm further to the end-side inner arm 3, and which chain element 4 may be connected to a chain tensioner arranged at the end region of the articulated arm 1 of the telescopic crane. In this patent application the chain element 4 may be a chain 4, wire 4, belt 4, cable 4, hydraulic hose 4 or any other suitable chain element 4 for transferring power or energy.

Figure 2 shows a detail of a longitudinal sectional view of an articulated arm of one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention. The telescopic boom arrangement of a telescopic crane according to the present invention comprises a chain element 4 leading inside an articulated arm 1 of the telescopic crane and a chain deflection roller 5 deflecting the chain inside said articulated arm 1. Here the chain element 4 may be a chain 4, wire 4, belt 4, cable 4, hydraulic hose 4 or any other suitable chain element 4 for transferring power or energy.

Figure 3 shows a detail of a longitudinal view of an articulated arm of one embodiment of a telescopic boom arrangement of a telescopic crane according to the present invention. The telescopic boom arrangement of a telescopic crane according to the present invention comprises a lubricating nipple 6 on outer face of an articulated arm 1 of the telescopic crane. In the telescopic boom arrangement of a telescopic crane according to the present invention the lubricating nipple 6 is used to lubricate a chain deflection roller 5 and a bearing arrangement of said chain deflection roller 5 as well as a chain element 4 leading inside the articulated arm 1 of the telescopic crane. Here the chain element 4 may be a chain 4, wire 4, belt 4, cable 4, hydraulic hose 4 or any other suitable chain element 4 for transferring power or energy.

Figure 4 shows a chain lubrication arrangement of a lifting device according to the present invention. The lifting device according to the present invention comprises a lubricating nipple 6 on outer face of the lifting device. In the lifting device according to the present invention the lubricating nipple 6 is used to lubricate a chain deflection roller 5 and a bearing arrangement of said chain deflection roller 5 as well as a chain element 4 leading inside the lifting device. Here the chain element 4 may be a chain 4, wire 4, belt 4, cable 4, hydraulic hose 4 or any other suitable chain element 4 for transferring power or energy.

As lubricant e.g. grease is applied to the lubricating nipple 6 of the lifting device according to the present invention first the lubricant enters through a lubricant channel 7 of the lubricating nipple 6. The chain deflection roller 5 according to the present invention has a lubrication chamber 8 as well as one or more lubrication channels 9, 10 inside the chain deflection roller 5. From the lubricant channel 7 of the lubricating nipple 6 the lubricant e.g. grease enters to the lubrication chamber 8 of the chain deflection roller 5 and thereafter to the lubrication channels 9, 10 of the chain deflection roller 5. The chain deflection roller 5 according to the present invention also comprises a bearing arrangement 11. Said bearing arrangement 11 may comprise a bushing bearing 11 or two or more rolling bearings 11 and a channel between said rolling bearings 11. Said bushing bearing 11 may be fixed to the inner surface 13 of the chain deflection roller 5. A bushing bearing 11 according to the present invention has holes along said bushing bearing 11. From the lubrication channels 9, 10 of the chain deflection roller 5 the grease enters to a shaft surface 12 of the chain deflection roller 5 and thereafter through said holes along said bushing bearing 11 or through said channel between said rolling bearings 11 towards inner surface 13 of the chain deflection roller 5. Thereafter the grease enters further to one or more 16, 17 channels in the chain deflection roller 5 to an outer surface 18 of the chain deflection roller 5. In the outer surface 18 of said chain deflection roller 5 the lubricant provides lubrication for said chain element 4. In the inner surface 13 of the chain deflection roller 5 there may be distribution grooves 14, 15 to help the grease distribution along the inner surface 13 of the chain deflection roller 5 and on to the one or more 16, 17 channels in the chain deflection roller 5.

In the chain lubrication arrangement of a lifting device according to the present invention the said bushing bearing 11 may have a sliding surface made of any kind of suitable sliding bearing material, such as e.g. bronze, sintered tin bronze, plastic, bearing plastic, composite, polytetrafluoroethylene or polyoxymethylene.

With the help of the solution according to the present invention the lubrication of the chain inside the articulated arm of the telescopic crane can be satisfactorily arranged. The lubrication solution according to the present invention provides a no good lubrication of the chain in the tight and cramped space inside the lifting device e.g. inside the articulated arm of the telescopic crane. The lubrication solution according to the present invention ensures the proper function and lifetime of the chain.

The chain lubrication solution according to the present invention can be used in any kind of lifting equipment such as cranes, telescopic cranes, loader cranes, articulating cranes or knuckle-boom cranes and in other lifting devices such as forklift stackers and other lifting machinery.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.