Abstract:
The disclosure describes a lifting system for use with a hoist, comprising of at least one structural frame rail, attached to middle portions of cross members on the opposite ends of the frame rail, such that the two cross members are co-planar. Each end of the cross member is attached to an attachment assembly. The attachment assembly comprises of an extension link and a detachable pin member assembly. On end of extension link is attached to the cross member and the other end is provisioned to receive the pin member assembly. A lifting lug assembly is structured and arranged at the center of the frame rail towards the upper face of the rail, to connect an external hoist for lifting in vertical direction. The lifting system as described above provides an easy lifting mechanism for heavy objects, such as an alternator of the electric drive trucks.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to a lifting system designed to lift a substantial component from a machine and more particularly to safely manage the heavy objects such as an alternator/generator, a motor, axle etc., from electric drive machines. 
       BACKGROUND 
       [0002]    Large machines, such as mining trucks, are known to employ electric drive propulsion systems to propel or retard the machine. Typically, an electric drive propulsion system includes an alternator, or other electrical power generator, powered by an internal combustion engine which drives an electric power generator, for example. The alternator, in turn, supplies electrical power to one or more electric drive motors connected to wheels of the machine. As these machines often work in dirt and mud, and require periodic servicing, oftentimes, the electrical units such as, alternator, electric motor, etc., are removed, repaired (or serviced) and reassembled during a normal course of service or repair. These electrical units are typically substantial in size, bulky and quite often very heavy. There is currently no special tool available to manage a wide variety of these components, using a single tool, for the removal, service and installation of the alternator and other large electrical components, particularly at the worksite. Therefore, it is required to have a low profile lifting system of lower weight for expeditious yet safe removal and moving of heavy electrical components. 
         [0003]    U.S. Patent No. 2012/0272496 (the &#39;496 patent) discloses a system and method for lifting a casing section, during servicing or maintenance of a gas turbine. Patent &#39;496 discloses a lifting system to clutch and lift the top section vertically in relation to the bottom section. This lifting system can be used to lift the top cover to a limited height and require expensive and complex supporting members to hold the top cover in the elevated position. Moreover, the lifting system disclosed is not a standalone system to be lifted and move objects from one place to other. 
         [0004]    A lifting system which may overcome one or more of these limitations and one that would be readily manufacturable would be desirable. Furthermore, an integrated lifting system which does not significantly add cost and one that does not increase the weight of the component to be lifted, and one which may be readily adaptable to many machine types to robustly secure a component is highly desirable. 
       SUMMARY OF THE INVENTION 
       [0005]    The disclosure describes, a lifting system for use with a hoist to exert an upward force on the lifting system associated with the lifting of a load, comprising of at least one structural frame rail, attached to middle portions of cross members on the opposite ends of the frame rail, such that the two cross members are parallel to each other and co-planar. A pair of attachment assemblies is attached to both cross members, such that each end of cross member is attached to an attachment assembly. The attachment assembly comprises of an extension link and a detachable pin member assembly. The extension link comprises of two cavities on each end, such that one cavity is used to connect the end of cross member therethrough and the other cavity for attaching a pin member assembly to secure the object to be lifted. A lifting lug is structured and arranged at the center of the frame rail towards the upper face of the rail, to connect an external hoist for lifting in vertical direction. The rail frame is structured and arranged to be in compressive force contact with the first and second cross members and the first and second cross members are structured and arranged to be in compressive force contact with each of the extension links of the first and second pairs of attachment assemblies in response to the load being applied to the attachment assemblies and corresponding upward force on the lifting lug assembly. A lifting system as described above provides an easy lifting mechanism for heavy objects, such as an alternator of the electric drive trucks. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a left side view of an electrical mining truck which possesses electrical components to be installed/removed using the present disclosure lifting system; 
           [0007]      FIG. 2  is a perspective view of the truck of  FIG. 1  with the bed lifted and the air, fuel, electrical and exhaust lines removed, to illustrate the typical field environment and space constraints associated with the use of the low profile lifting system to install and remove an alternator from a truck; 
           [0008]      FIG. 3  is a perspective view of the lifting system of  FIG. 2 , showing the frame, cross member, lifting lug assembly, and detachable pin members etc.; 
           [0009]      FIG. 4  is a partial exploded view of the lifting system shown in  FIG. 3 . 
           [0010]      FIG. 5  is an exploded view of the lifting lug assembly shown in  FIG. 4  depicting the mounting plate and frame rail details; 
           [0011]      FIG. 6  is an exploded view showing the detachable pin, extension link, washer, and lock pin, and relationship therebetween; and 
           [0012]      FIG. 7A  and  FIG. 7B , are diagrammatic partial views showing elements of the present disclosure lifting system assembly and specifically illustrating the usage of multi-lifting connections between view  7 A and  7 B. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIG. 1 , an off-highway truck  10  having a load body  18 , includes a frame  12  having rear wheels  16  and front wheels  20  mounted to axles (not shown) which in turn are mounted to the frame  12  as is customary. An operator&#39;s station  14 , which is positioned adjacent an engine compartment  19  ( FIG. 2 ), is mounted at one end of the frame  12 . The off-highway truck  10  may include an electric powertrain (not shown) having an engine (not shown), for example, an internal combustion engine, for providing the off-highway truck  10  with mechanical energy. The engine (not shown) is operatively associated with an electric power generator (not shown), mounted within the engine compartment  19 , and may drive the electric power generator (not shown) such that the electric power generator (not shown) converts the mechanical energy from the engine (not shown) into electric energy. Thus generated electric energy can be coupled to rear wheels  16 , through electric drive motors (not shown). The load body  18  is pivotally attached to the frame  12  by a pair of body supports  17 . 
         [0014]    Referring to  FIG. 2 , as these trucks are continuously operated and are typically in harsh environments, periodic servicing of electrical systems is required. A typical electric system associated with truck  10  may include an alternator  22 , drive motors (not shown), inverter (not shown), etc. These electrical components are heavy and may require careful attention during their assembly and disassembly. For example, an alternator  22  used in a large electric or hydraulic mining truck  10  may weigh more than 10,000 lbs. 
         [0015]    In  FIG. 2 , certain components of the truck, such as a rectifier, grid, blower, inverter, etc., are not shown in order to illustrate the partially disassembled truck in preparation to receive the alternator  22 . To lift or install the alternator  22  assembled on a truck  10 , the load body  18  should be lifted such that it exposes the electrical component and then a hoist  49  may be positioned at a desired location, and allowed to lower chains  46 . In an exemplary embodiment, a service truck (not shown) with hoist is used for this purpose. The service truck is parked at an appropriate location next to the truck  10 . The chains  46  of the hoist  49  may be connected to a lifting system  24  which has been previously attached to the alternator  22 , as will be described hereinbelow. 
         [0016]    Lifting system  24  is mounted on the alternator  22 , and the lifting system  24  along with the alternator  22  is supported by the cylindrical-shaped hoist  49 . The hoist may be an electric,  10  ton hoist and supported by a foundational member  48  such as a metal beam as is customary. The lifting system  24  can be used to carry heavy loads such as drive shafts (not shown), traction motors (not shown), inverter cabins (not shown), etc. 
         [0017]    Referring to  FIG. 3 , the lifting system  24  will now be described. Lifting system  24  may include a rectangular frame rail  26 , having a first end  60  and a second end  62  and a center portion  64 . The frame rail  26  is a significant structural member and is attached substantially perpendicular with two cross members  28 . It is envisioned that cross members  28  could be welded to respective first and second ends  60 ,  62  of the frame rail  26  by any other method known to those having ordinary skill in the art. Each cross member  28  has a first end  70  and a second end  72  and a middle section  74 . The first end  60  of frame rail  26  is connected to the middle section  74  of each cross member  28  and the second end  62  of frame rail  26  is connected to the middle section  74  of the other cross member  28 . Attachment assemblies  29  are connected to each end  70  and  72 , respectively of the pair of cross members  28  providing four attachment assemblies  29  for lifting system  24 . Each of the four attachment assemblies  29  has an extension link  30  with a rectangular aperture  31  ( FIG. 4 ), to accommodate the ends  70 ,  72  of the pair of cross members  28  extending therethrough. 
         [0018]    Referring to  FIG. 4 , it may be seen that four triangular shaped gussets or support members  36  are configured to each have two adjacent edges, i.e. first end  76  and second end  78  therein that are generally orthogonal to one another. Each support member  36  is welded along the intersection of the support member  36  and the cross member  28  and along the intersection of the support member  36  and the frame rail  26  at the specified first end  76  and second end  78  of each support member  36  ( FIG. 3 ). The support members  36  provide additional support and rigidity to the lifting system  24 . Frame rail  26  includes mounting face  66  and orientation arrows  50  ( FIG. 4 ) attached to the mounting face  66  to aid a service person assembling the lifting system  24  to the alternator  22  to ensure the lifting system  24  is properly oriented relative to a front  79  of the alternator  22  ( FIG. 2 ). 
         [0019]    Referring again to  FIG. 4 , the center portion  64  of the frame rail  26  may have two distinct and alternatively used threaded holes  67 ,  69 , placed to coincide with different size alternators. Since each alternator is likely to have its own specific center of gravity the threaded holes  67  and  69  correspond with different size alternators each having distinct centers of gravity. Thus, the proper threaded hole  67 ,  69  can be selected and used to lift the lifting system  24  to insure that the frame rail  26  (and alternator shaft alignment) remains relatively horizontal during lifting. A mounting plate  38  having mounting holes  37 ,  39 , may be attached, by welding for example, to the mounting face  66  of the center portion  64  of frame rail  26  such that the first mounting hole  37  is in line with first threaded hole  67  and the second mounting hole  39  is in line with the second threaded hole  69 . In an exemplary embodiment, the mounting plate  38  may be made up of hardened steel and the mounting holes  37 ,  39  may be threaded, to provide additional strength and positive thread engagement for the lifting system  24 . A lifting lug assembly  40 , which may be connected to the mounting holes ( 37  or  39 ), is hereinafter described. 
         [0020]    Referring to  FIG. 5 , the lifting lug assembly  40  may include a lifting lug or eye-bolt type threaded fastener  44  (“eye bolt  44 ”), such that the eye-bolt  44  has a single chain link adapted to connect to a hook at the end of a the chain  46  (shown in  FIG. 2 ) of the hoist  49 , as is customary. The thickness of mounting plate  38  may be selected, such that an appropriate number of threads are engaged between the eye-bolt  44  and mounting plate  38 , for a full threaded bolted joint connection. The strength of bolted joint connection thus formed may depend on the size of thread on eye-bolt  44 , which may in turn depend on the weight of the object to be lifted. Referring to  FIG. 6 , the lifting system  24  has four attachment assemblies  29  ( FIG. 3 ), however further explanation of each attachment assembly  29  may be best explained with reference to  FIG. 6 . Each attachment assembly  29  includes an extension link  30 , a detachable pin member  32 , a lock pin  34  and a washer  35 . The pin member  32  is slidably engaged with the extension link  30  through an aperture  33  formed in the extension link  30 . The pin member  32  includes first end  56 , second end  57 , and middle portion  58 . At a location toward end  57  of the middle portion  58  of pin member  32  is a radially positioned hole  59 . The first end  56  of pin member  32  includes a head as is customary and the second end  57  has the hole  59  to receive lock pin  34  to ensure pin member  32  is properly retained in extension link  30 . The pin member  32  is of sufficient length to passthrough both sides of a mounting bracket  80  provided on alternator  22  ( FIG. 2 ). 
         [0021]    Referring now to  FIG. 7A  and  FIG. 7B , the alternative mounting options for lifting lug assembly  40  will now be described. In  FIG. 7A , the lifting lug assembly  40  may be fastened into mounting hole  39  for a first type of alternator  22  ( FIG. 2 ). Alternatively, and as shown in  FIG. 7B , lifting lug assembly  40  may be fastened into mounting hole  37  for a second type of alternator  22  ( FIG. 2 ). 
         [0022]    As best seen in  FIG. 3 , the assembly of the exemplary lifting system  24  will now be described. The connection between: frame rail  26  and cross members  28 ,; cross member  28  and each of the attachment assemblies  29 ,; support members  36  and frame rail  26  and cross member  28  are metal to metal connections perhaps carbon steel and permanently affixed by welding all abutting connection points. Alternatively the aforesaid connections can be permanently fixed by fastening or any other permanent fastening technique known by those having ordinary skill in the art of joining materials similar or dissimilar materials. 
         [0023]    In an exemplary embodiment, the structural components such as frame rail  26  and cross members  28  may be made out of readily available rectangular bar stock or rectangular tube stock having a rectangular or square cross-section and being made from carbon steel or other type of commonly available material with suitable structural integrity. Other types of materials known to those with ordinary skill in the art that could be used to construct the structural members of the lifting system  24  are contemplated by the present disclosure. 
       INDUSTRIAL APPLICABILITY 
       [0024]    The lifting system  24 , described above is economical, lighter in weight, easily manufacturable and made out of inexpensive and readily available material. The construct of lifting assembly  24  is designed such that substantially all of the permanently fixed (i.e., welded) joints in the structural members are in compression such that the quality of the welds will have little or no effect on the overall integrity of the lifting system. For example, lifting force acing on the lifting lug assembly  40 , transmits through various structural members to the mounting location (not shown) of the alternator  22 , such that there is a compressive force between the frame rail  26  and cross members  28  or between cross members  28  and the connected attachment assembly  29 . The design of the lifting system  24  as described above may be easier to manufacture, assemble and yield a higher integrity system resulting in an improved life due to the compressive forces as described. In particular, the customary service trucks used in the fields have a particular weight lifting capacity and are often times much shorter in height compared to a mining truck, such as the one illustrated in this disclosure. Therefore, a lightweight, low profile and simple lifting system is disclosed above, that can easily maneuver into the space available between the load body and chassis and the lifting system is easy to assemble/disassemble to the hoist of the service truck and the alternator or component to be lifted. The lifting system is constructed of a relatively light weight structure and one that is easy to manufacture and assemble. 
         [0025]    Referring to  FIG. 2 , in operation to remove the alternator  22  assembled on a machine, such as an off-highway truck  10  with its load body  18  lifted, the lifting system  24  may be linked to the hoist  49 , by attaching the eye-bolt  44  of lifting lug assembly  40  to the chain  46 . The foundational member  48  and the hoist  49  are adjusted such that the lifting system is moved and placed over the alternator  22 . At each corner of the lifting system  24 , the lock pin  34  is temporarily removed, and the pin member  32  is inserted through the extension link  30 , such that the second end  57  of each pin member  32  passes through each saddle or mounting bracket  80  on the alternator  22 . The box-type mounting brackets  80  fixed on the alternator may be constructed, as is customary, from suitable gage thickness carbon steel plate and welded together and permanently affixed to the outer portion of the alternator  22  in four places. To secure each attachment assembly  29  to each mount  80  on the alternator  22 , each washer  35  is inserted over an associated pin member  32  and a lock pin  34  is inserted through each radial hole  59  in the pin member  32 , such that the extension link  30 , mount  80  on the alternator  22 , and washer  35  are sandwiched between each lock pin  34  and the first ends  56  of each pin member  32 . The same procedure is repeated on remainder of the three attachment assemblies  29 , to secure the alternator  22  with the lifting system  24 . When all four lock pins  34  are in place within the pin members  32 , the hoist  49  is operated to lift the alternator  22  along with the lifting system  24  and moved to desired location. To remove the lifting system  24  from the alternator  22  once the alternator  22  is safely resting in its final destination, the lock pins  34  are removed and the pin members  32  are then removed. Thereafter the lifting system  24  may be moved out of place with the hoist  49 . 
         [0026]    Although the embodiments of this disclosure as described herein may be incorporated without departing from the scope of the following claims, it will be apparent to those skilled in the art that various modifications and variations can be made. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.