Patent Publication Number: US-2015078869-A1

Title: Mobile service trailer with crane

Description:
FIELD 
     There is described a mobile service trailer, which has a built in crane. 
     BACKGROUND 
     Mobile service trailers are frequently used to transport equipment to job sites. However, without lifting capacity the mobile service trailer can only be used to service objects that can be manually lifted into the trailer. What is required is a mobile service trailer with lifting capacity. 
     SUMMARY 
     There is provided a mobile service trailer with crane which has a trailer platform resting upon ground engaging wheels. The trailer platform has a front end, a rear end, a first side, a second side, and a trailer hitch support extending forward of the front end. A plurality of structural support columns extend vertically from the trailer platform at spaced intervals along both of the first side and the second side. A plurality of roof support members are supported by the support columns and span the width of the platform between the first side and the second side. A first guide track is suspended underneath and extends between the roof support members. A first crane is positioned on an elongated trolley which travels along the first guide track between an extended position and a retracted position. In the extended position, the trolley extends past the rear end of the trailer platform in a cantilever fashion to enable the first crane to reach and lift an object positioned behind the trailer platform. In the retracted positioned, the trolley is retracted to enable the first crane to deposit the object onto the trailer platform. 
     The mobile service trailer, described above, can be backed up to a piece of equipment needed servicing. The trolley can then be extended in cantilever fashion over the piece of equipment and the first crane can be used to lift it. The trolley can then be retracted, so that the piece of equipment can be lowered onto the trailer platform adjacent to the work station where the piece of equipment is to be serviced. There are various ways of configuring the first guide track. Beneficial results have been obtained when the roof support members have a depending framework and the first guide track is defined by a channel defined by the framework which accommodates the trolley. 
     For some pieces of equipment, servicing requires multiple work stations. In such a situation, it may be necessary to repeatedly reposition the piece of equipment on the trailer platform to access different work stations. In such cases, a second guide track may be provided extending between the front end and the rear end, with the second guide track being supported by the support columns. A second crane can then be positioned on a beam that extends across the trailer platform between the first side and the second side. The second crane is capable of travelling along the beam between the first side and the second side. The beam is capable of travelling along the second guide track between the front end and the rear end. This enables the second crane is able to lift the object deposited by the first crane and reposition the object axially and laterally to any desired location on the trailer platform. There are various ways in which the second guide track can be configured. Beneficial results have been obtained when the support columns have an upper ledge and the second guide track is comprised of parallel crane rails. One of the crane rails is positioned on the upper ledge of the support columns the first side of the trailer platform and another of the crane rails positioned on the upper ledge of the support columns on the second side of the trailer platform. 
     It is preferred that the trailer platform be is enclosed by sheeting secured to an outside of the support columns and roof support members. The reason this is preferred is that it provides a working environment that is sheltered from the elements and it provides better security against trespass and theft of tools. It will be appreciated, however, that the trailer platform need not be enclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein: 
         FIG. 1  is a side elevation view of a mobile service trailer. 
         FIG. 2  is a detailed side elevation view of the mobile service trailer of  FIG. 1  with trolley partially extended to position the first crane. 
         FIG. 3  is a rear elevation view of the mobile service trailer of  FIG. 1  with the trolley retracted into the first guide track. 
         FIG. 4  is a top plan view, in section, of the mobile service trailer of  FIG. 1  showing possible mobile service shop layout with various work stations. 
         FIG. 5  is an end elevation view, in section, of the mobile service trailer of  FIG. 1  showing the second crane and the beam engaged on the second guide track. 
     
    
    
     DETAILED DESCRIPTION 
     A mobile service trailer generally identified by reference numeral  10 , will now be described with reference to  FIG. 1 through 5 . 
     Structure and Relationship of Parts: 
     Referring to  FIG. 1 , a mobile service trailer with crane  10  has a trailer platform  14  resting upon ground engaging wheels  16 . Trailer platform  14  has a front end  18 , a rear end  20 , a first side  22 , a second side  24  (visible in  FIG. 3  and  FIG. 4 ), and a trailer hitch  26  support extending forward of front end  18 . Mobile service trailer  10  may also have a side door  15  for personnel access. Referring to  FIG. 3 , a plurality of structural support columns  28  extend vertically from trailer platform  14  at spaced intervals along both of first side  22  and second side  24 . A plurality of roof support members  30  supported by support columns  28  and spanning the width of platform  14  between first side  22  and second side  24 . Trailer platform  14  may be enclosed by sheeting  32  around the outside of support columns  28  and roof support members  30 . A first guide track  34  is suspended underneath roof support members  30 . Roof support members  30  have depending framework  36  and first guide track  34  is defined by a channel  35  defined by framework  36  which accommodates trolley  38 . A first crane  40  is positioned on trolley  38  which travels along first guide track  34  between an extended position and a retracted position. Referring to  FIG. 2 , in the extended position, trolley  38  extends past rear end  20  of trailer platform  14  in a cantilever fashion to enable first crane  40  to reach and lift an object positioned behind trailer platform  14 . In the retracted positioned, trolley  38  is retracted to enable first crane  40  to deposit the object onto trailer platform  14 . 
     Referring to  FIG. 5 , mobile service trailer  10  has a second guide track  44  extending between front end  18  and rear end  20  and is supported by support columns  28 . Support columns  28  have an upper ledge  46  and second guide track  44  is comprised of parallel crane rails  48  with one of crane rails  48  positioned on upper ledge  46  of support columns  28  on first side  22  of trailer platform  14  and another of crane rails  48  positioned on upper ledge  46  of support columns  28  on second side  24  of trailer platform  14 . A second crane  50  is positioned on a beam  52  that extends across trailer platform  14  between first side  22  and second side  24 . Second crane  50  travels along beam  52  between first side  22  and second side  24 . Beam  52  travels along second guide track  44  between front end  18  and rear end  20 , such that second crane  50  is able to lift the object deposited by first crane  40  and reposition the object axially and laterally to a desired location on trailer platform  14 . 
     Referring to  FIG. 4 , mobile service trailer  10  may have several different work stations to allow an object to be worked on with different equipment. Work stations available in mobile service trailer  10  may include a work bench  54 , a welder or plasma cutter  56 , a band saw  58 , welders  60 , a hydraulic press  62 , tool chests  64 , a wash tank  66 , a drill  68 , bolt bins  70 , a lathe  72 , a pressure washer  74 , an air compressor  76 , a generator  78  and a fuel tank  80 . It will be understood that other types of work stations and equipment may be positioned within mobile service trailer  10  depending upon what type of objects are to be worked on. 
     Operation: 
     Referring to  FIG. 1 , mobile service trailer  10  is positioned such that rear end  20  of trailer  10  is near object to be lifted. Referring to  FIG. 2 , trolley  38  is extended past rear end  20  of trailer  10  to allow first crane  40  to be used to pick up objects. Once object has been picked up, trolley  38  is retracted to position object on trailer platform  14 . Referring to  FIG. 5 , second crane  50  can then be used to reposition object to different work stations in mobile service trailer  10 . Second crane  50  is movable along beam  52  between first side  22  and second side  24  of mobile service trailer  10  and beam  52  is movable along length of second guide track  44  to allow repositioning of object axially and laterally. 
     In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. 
     The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.