Abstract:
An industrial truck comprising a pair of wheel arms, which at their free end in each case comprise a wheel arm end, each of which comprising a bearing body and a pair of load wheels, the load wheels in each case being rotatably mounted on a rocker, and the rocker being pivotably mounted on the bearing body in a region located between the load wheels, the bearing body comprising a bearing projection on which the rocker is mounted such that the rocker laterally defines the wheel arm end.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
       [0002]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates to an industrial truck comprising a pair of wheel arms. The present invention relates, in particular, to straddle trucks and reach trucks which comprise a pair of wheel arms. 
         [0004]    The known industrial trucks comprising wheel arms have at the free ends of the wheel arms one respective wheel arm end, each of which comprising a bearing body connected to the wheel arm and a pair of load wheels or load rollers. 
         [0005]    An industrial truck comprising wheel arms has been disclosed in DE 10 2008 034 614 A1, the entire contents of which is incorporated herein by reference, said wheel arms being fastened to a vehicle frame by means of adapter blocks. The free end of the wheel arms comprises a U-shaped holder, the limbs of the holder being connected to the wheel arms, and the connection between the limbs forming the free end of the wheel arms. The load wheels are arranged between the U-shaped limbs. 
         [0006]    A wheel arm end for an industrial truck has been disclosed in US 2008/0308539 A1, the entire contents of which is incorporated herein by reference, said wheel arm end comprising a recess in which a rocker is pivotably arranged. The wheel arms are in this case defined laterally by a pair of outer walls on the wheel arm end, between which the rocker is arranged. 
         [0007]    The object of the invention is to provide an industrial truck which has the narrowest possible wheel arms with the largest possible width of the load wheels. 
         [0008]    According to the invention, the object is achieved by the inventive industrial truck. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The industrial truck according to the invention comprises a pair of wheel arms, as for example is the case in straddle trucks and reach trucks. The wheel arms at their free ends are provided in each case with a wheel arm end which may be configured integrally with the wheel arm or as a separate component connected to the wheel arm. Each wheel arm end comprises a bearing body and a pair of load wheels. In the present application, no distinction is made between load wheels and load rollers, but the term “load wheel” is used throughout. The load wheels are in each case rotatably mounted at one end of a rocker, the rocker being pivotably mounted on the bearing body of the wheel arm end in a region located between the load wheels. According to the invention, the bearing body comprises a bearing projection on which the rocker is mounted such that the rocker laterally defines the wheel arm end. The lateral limit of the wheel arm end relates in this case to the longitudinal direction of the wheel arms. In contrast to the known solutions, in the embodiment according to the invention of the wheel arm end, an outer face of the rocker forms the lateral limit of the wheel arm end. This is achieved by the rocker being pivotably fastened to a bearing projection of the bearing body and not, as known from the prior art, to the side walls of the wheel arm end. 
         [0010]    In a preferred development, the bearing body comprises two opposing side walls, transversely to a longitudinal direction of the wheel arm, the bearing projection being arranged such that the side walls are arranged in each case above the rocker. In this preferred embodiment of the wheel arm end, the side walls do not extend over the entire height of the wheel arm end but are configured so that they are located above the rocker and thus a larger width is available for the rocker. 
         [0011]    In a preferred embodiment, the outer face of the side walls is substantially aligned with an outer face of the rocker. In this manner, the load wheels rotatably mounted on the rocker may be configured to be wider and thus have improved rolling behaviour, while the load arms have the same overall width. 
         [0012]    In a preferred embodiment, the side walls and in this case, in particular the side walls with their bottom edge, form stops for the rocker in order to limit a pivoting movement of the rocker. 
         [0013]    Whilst in a preferred embodiment the side walls are arranged above the rocker, the load wheels mounted on the rocker are partially covered at the side by the side wall of the bearing body. 
         [0014]    In a preferred embodiment of the wheel arm end, the bearing body has a substantially rectangular shape, the bearing body comprising a base plate with a connecting wall facing towards the wheel arm, and two lateral side walls, between which the bearing projection is arranged on the base plate. According to the invention, the force transmission of the wheel arm end takes place substantially via the bearing projection and the base plate towards the connecting wall, from where the force is introduced into the wheel arm. By the flux of force via the base plate of the bearing body, the side walls may be partially dispensed with, without loss of stability for the wheel arm end, as a result of which where the load wheels have the same width, the wheel arm end may be of narrower construction or with a predetermined width of the wheel arm end, wider load wheels may be used. 
         [0015]    In a preferred embodiment of the bearing body, the bearing projection protrudes over the side walls, so that to the side of the bearing body the rocker and the side walls may form an end portion for the wheel arm end. 
         [0016]    In a preferred embodiment, the side walls have in each case a curved contour which forms a stop surface for the rocker in order to limit the pivoting movement of the rocker. 
         [0017]    In a preferred embodiment, the rocker comprises two arms, between which the load wheels are arranged. The arms of the rocker may be configured, for example, as planar, plate-shaped elements, between which the load wheels are rotatably mounted. Preferably, in the mounted state of the rocker, the bearing projection is arranged between the arms of the rocker. 
         [0018]    In a further preferred embodiment, the bearing body at its end facing away from the wheel arm has a front wall which in the longitudinal direction has a curved contour, such that the transition from the base plate to the front wall on the side facing away from the load wheels has an arcuate path. The curved transition between the front wall and the base plate facilitates, on the one hand, moving underneath a load to be received. At the same time, a front wall of such a configuration permits a deformation of the wheel arm end to be absorbed via the base plate so that the wheel arm end also remains functional. 
         [0019]    In order to be able to absorb easily forces which occur in the event of a collision and to ensure a further operation of the wheel arm end, preferably the front wall has a smaller wall thickness than the base plate. As a result, preferably plastic deformations occur in the front wall whereby part of the impulse is already absorbed. 
         [0020]    In a further preferred embodiment, the front wall tapers to the side relative to the longitudinal direction of the wheel arms towards the free end. This tapering permits loads to be more easily received, as the wheel arm end is not able to become caught at the side on a load to be received. Even in the event of a collision, the tapered tip permits improved absorption of the shock impulse. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0021]    An advantageous embodiment of the invention is described in more detail hereinafter with reference to the figures, in which: 
           [0022]      FIG. 1  shows the wheel arm end according to the invention in a perspective view obliquely onto a connecting wall, 
           [0023]      FIG. 2  shows a perspective view of the wheel arm end mounted on the wheel arm, 
           [0024]      FIG. 3  shows a view of the wheel arm end from the side and 
           [0025]      FIG. 4  shows a plan view of the wheel arm end. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated. 
         [0027]      FIG. 1  shows a bearing body  11  of a wheel arm end  10  with a base plate  12 , a side wall  14 , a front wall  16  as well as a connecting wall  18 . The bearing body  11  shown is fastened with its connecting wall  18  to one end of the wheel arm, for example by welding. For improved orientation of the wheel arm end on the wheel arm, the connecting wall  18  has in its centre a V-shaped recess  20  into which a corresponding projection on the wheel arm may engage in order to position the bearing body  11  on the wheel arm. The side wall  14  has a curved contour  22  to the side, the contour at its end facing the front wall  16  and the connecting wall  18  having a greater height. The base plate  12  is positioned on the front wall  16  or configured integrally therewith. The front wall  16  has a height H which is greater than the height h of the connecting wall (see  FIG. 3 ). 
         [0028]    A bearing projection  24  is arranged centrally on the base plate, said bearing projection having a substantially parallelepiped shape. The bearing projection  24  has a through-bore  26  which extends transversely to the longitudinal direction of the load arm. The bearing projection  24  may be configured integrally with the base plate  12  or screwed thereon, for example through a bore  28 . 
         [0029]      FIG. 2  shows the wheel arm end of  FIG. 1  with the fully mounted wheels on a partially shown wheel arm  30 . The wheel arm  30  has a substantially rectangular cross section, the wheel arm end  10  being fastened with its connecting wall  18  to the front end of said wheel arm. The side walls  14  of the wheel arm end are connected to the side walls  32  of the wheel arm in a manner which is coplanar and aligned therewith. 
         [0030]    Below the side wall  14 , an arm  35  of the rocker for the load wheels  36 ,  38  may be seen. The arm  35  of the rocker is centrally mounted via a shaft  40  in the bearing projection  24  and the through-bore  26  thereof The load wheels  36  and  38  are in each case rotatably mounted via bearing elements  42  and/or  44  at the ends of the arm  35  of the rocker. It is significant in the view in  FIG. 2  that approximately in the regions A the arm  35  of the rocker comes into contact with a lower face of the side wall  14 . The arrangement of the arm  35  of the rocker below the side wall  14  is possible as the rocker is mounted on the bearing projection  24  and not inside the side wall  14 . 
         [0031]    Both in  FIG. 1  and in  FIG. 2 , the side wall, not shown, and the side, not shown, of the rocker are formed corresponding to the side wall  14  and/or corresponding to the arm  35  of the rocker. 
         [0032]      FIG. 3  shows the wheel arm end according to the invention in a view from the side. As already mentioned, the front wall  16  has a greater height H than the connecting wall  18  with a height h. The bearing projection  24  is arranged with its through-bore  26  approximately centrally on the base plate  12 . It may be clearly seen in  FIG. 3  that the front wall on its front face has an arcuate contour  46 , the contour  46  on the lower face of the front wall rising approximately vertically and merging in an arcuate manner with the approximately horizontal base plate  12 . In the event of a collision of the industrial truck, the front wall  16  bends inwards in the direction of the bearing projection  24 , a not inconsiderable part of the impulse which is produced during the collision being absorbed by a plastic deformation of the front wall  16  and the base plate  12 . 
         [0033]    The bearing projection  24  and the stop surfaces A formed by the side wall  14  are not altered in their position by such a collision, so that further smooth operation of the industrial truck is possible. 
         [0034]      FIG. 4  shows the wheel arm end in a plan view, in which it may be seen that the front wall  16  with its end facing forward has a portion  50  which has a width b, which is smaller than the overall width B of the wheel arm end. The front portion  50  in each case merges via an arcuate portion  48  with the side wall. 
         [0035]    The contour of the front wall  16  is configured such that, in the event of a collision at full speed and at nominal load, the energy produced in the event of a collision may be reduced by plastic deformation of the front wall, and damage to further structural elements or components on the industrial truck is prevented. In this case, the front wall  16  is designed so that the vehicle remains operational even in the event of repeated collisions. 
         [0036]    The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. 
         [0037]    Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim  1  should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below. 
         [0038]    This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.