Abstract:
An operator cab for a work vehicle is releasably mounted to a frame of the vehicle via a cab support pin and a flexible mount during vehicle work operations and rotationally attached via the cab support pin for servicing working parts of the work vehicle. An anchor arrangement for the cab support pin helps to maintain the position of the cab with respect to the cab support pin during work and service operations.

Description:
FIELD OF THE INVENTION 
     This disclosure relates to tilting mechanisms and, more particularly, to tilting mechanisms for pivotally mounted operator cabs for work vehicles. 
     BACKGROUND OF THE INVENTION 
     Operator cabs for work vehicles are often mounted over working components of the vehicles such as engines, transmissions, etc., which usually generate noise and vibration. Thus, in order to reduce the noise and vibration experience of operators, operator cabs are, at times, mounted to the frames of the vehicles via flexible connections designed to absorb vibrations and to, thereby, reduce noise inside the cabs. These cabs must have travel limiting devices as part of the roll over protection structure (ROPS) to restrict cab travel empowered by the flexible mounts as unexpected loads may enable cab travel to greater distances than acceptable. Further, such operator cabs must be somehow removable with respect to the frame of the vehicle in order to allow room to effect the inevitable servicing of the working components over which they, i.e., the cabs, are positioned. Traditionally, such cabs are removed from the service area via rotation toward the front, the rear, or either side of the vehicle using a corresponding hinge at the axis of rotation (see, for example, U.S. Pat. No. 7,607,721) or completely removed, via lift-off, from the frame of the vehicle (see, for example, US Patent Application Publication 2010/017662 A1) but these traditional solutions tend to be complex and/or inefficient when flexible mounts are used due to the nature and structure of the flexible mounts. 
     SUMMARY OF THE INVENTION 
     A vehicle includes a frame and an operator cab. The operator cab is attached to the frame via at least one mounting assembly capable of flexibly mounting the cab to the frame in a first adjustment and pivotally connecting the cab to the frame in a second adjustment where the first adjustment is for cab isolation and roll over protection during vehicle operations and the second adjustment is for service access to the vehicle. A flag pin serves as a motion limiting device for roll over protection in the first adjustment and as part of the pivotal connection in the second adjustment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will be described in detail, with references to the following figures, wherein: 
         FIG. 1  is a side view of a frame for a work vehicle having an operator cab releasably mounted to it (the frame) via a front mounting assembly and a rear mounting assembly; 
         FIG. 2  is an enlarged oblique view of the front mounting assembly from a first side of the frame; 
         FIG. 3  is an enlarged oblique view of the rear mounting assembly from the first side of the frame; 
         FIG. 4  is a side view of a cab support pin; 
         FIG. 5  is an oblique view of the cab support pin of  FIG. 4 ; 
         FIG. 6  is an enlarged oblique view of the rear mounting assembly of  FIG. 3  from a second side of the frame; 
         FIG. 7  is an oblique view of a cab attachment bracket; 
         FIG. 8  is a side view of the cab attachment bracket of  FIG. 6 ; 
         FIG. 9  is an oblique view of a travel limiting bracket; 
         FIG. 10  is a side view of the cab attachment bracket of  FIG. 8 , the travel limiting bracket of  FIG. 9  and the cab support pin of  FIG. 5  after assembly; 
         FIG. 11  is a perspective view of the rear mounting assembly of  FIG. 6  after the cab is rotated; 
         FIG. 12  is a side view of the cab and the rear mounting assembly when the mounting assembly is adjusted for vehicle operations; and 
         FIG. 13  is a side view of the cab and the rear mounting assembly when the mounting assembly is adjusted for vehicle servicing. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates an exemplary embodiment of a frame  10  of a working vehicle such as, for example, a dozer (not shown) having ground engaging tracks (not shown) and an operator cab  20 . Underneath the cab  20 , and attached to the frame  10  may be other conventional working components (not shown) of the vehicle which help to generate noise and vibration underneath the cab  20 . Attaching the cab  20  to the frame  10  are front cab support assemblies  30  and rear cab support assemblies  100  on the left and right sides of the cab. The front and rear cab support assemblies  30 ,  100  will be described for only one side of the frame  10  as, in this exemplary embodiment, they may be identically reflected on the other side of the frame  10 . 
     The cab  20  includes a roof  21 , two front support posts  23  (alternatively called A posts), two side support posts (alternatively called B posts)  24 , two rear support posts (alternatively called C posts)  25 , and a floor  26 . The cab  21  has a lower portion  21   a  toward the front of the cab  20  and a higher portion  21   b  toward the rear of the cab  20 . 
     As illustrated in  FIG. 2 , in this exemplary embodiment, the cab  20  is supported at B post  24  via a front cab support assembly  30  which includes: a channel shaped front support bar  31  spanning the width of the cab  20  between the two B posts  24 ; a front support plate  32  welded to an end of the front support bar  31  and having an anchor hole  32   a  and a clearance hole  32   b ; a front mounting pad  33  welded to the frame  10  and including threaded holes (not shown), a lower mounting pad support area  33   a , an elevated mounting pad support area  33   b , damper hole (not shown) and threaded motion limiter attachment hole (not shown); a motion limiter bolt assembly  34  including a motion limiter bolt  34   a  having a diameter less than the diameter of the clearance hole  32   b  and a motion limiter washer  34   b  welded thereto and having a diameter greater than the diameter of the clearance hole  32   b ; a conventional viscous damper  35  having a suspension anchor hole  35   a  (see  FIG. 11 ), and a damper attachment bracket  35 ′ with damper attachment holes  35   b  (See  FIGS. 3 and 11  also); damper attachment bolts  35   c ; and a suspension anchor bolt  36 . 
     As illustrated in  FIG. 2 , in this exemplary embodiment, the damper attachment bolts  35   c  connect the viscous damper  35  to the mounting pad  33  and, thereby, to the frame  10  via the threaded holes  33   c . The suspension anchor bolt  36  connects the front support plate  32  and, thereby, the front support bar  31 , to the viscous damper  35  via the threaded damper mounting hole  35   a  (see  FIG. 9 ), establishing a flexible and damped suspension for the cab  20  at the B post  24 . 
     As illustrated in  FIG. 2 , the motion limiter bolt  34   a  extends through the clearance hole  32   b  and is secured to the raised mounting pad support area  33   b  by threaded attachment via a threaded motion limiter attachment hole (not shown). The distance provided between the front support plate  32  and the motion limiter washer  34   b , when the front support plate is resting atop of the elevated mounting pad support area  33   b , provides a limited area in which the front support plate  32 , and thus, the cab  20 , may vertically move with respect to the frame  10 , the motion limiter bolt assembly  34  and the elevated mounting pad support area  33   b  restricting further vertical movement as the motion limiter washer  34   b  and the elevated mounting pad support area  33   b  are of greater diameter than the clearance hole  32   b.    
     A first portion  35   d  of the damper  35  extends above the damper attachment bracket  35   b . A second portion  35   e  of the viscous damper  35  extends below the damper attachment bracket  35 ′ and through the damper hole  33   c  (see  FIG. 11 ). 
     As illustrated in  FIG. 3 , the cab  20  is supported near C post  25  via a rear cab support assembly  100 , including: a cab support pin  110 ; a cab attachment bracket  120 ; a rear mounting pad  130  welded to the frame  10  over the fuel tank (not shown) and having a lower rear mounting pad portion  130 ′ and an elevated rear mounting pad portion  130 ″; a travel limiting bracket  140  welded to the rear mounting pad  130 ; a rear support plate  150  welded to the rear cab panel  26  and the cab attachment bracket  120  and including a rear anchor hole  150 ′ (see  FIG. 11  also); and a conventional viscous damper  35  having a threaded anchor hole  35   a  and damper attachment bracket  35 ′ with holes  35   b  (see  FIG. 11  also); rear suspension anchor bolt  151 ; and damper attachment bolts  35   c.    
     As illustrated in  FIGS. 4 and 5 , the cab support pin  110  includes a flag  111  at a first end  110   a  of the cab support pin  110  and a shank  112  having a groove  112   a , the groove positioned near a second end  110   b  of the cab support pin  110 . The flag  111  includes cab support holes  111   a  and anchor holes  111   b . Dual anchor holes  111   b  exist to allow each cab support pin  110  to be similarly located angularly regardless of the side of the frame  10  on which it is placed. 
     As shown in  FIG. 6 , in this exemplary embodiment the damper attachment bolts  35   c  connect the viscous damper  35  to the mounting pad  130  and, thereby, to the frame  10  of the vehicle (not shown) via the damper attachment holes  35   b  and the threaded holes (not shown) in the rear mounting pad  130 . As illustrated, a first portion  35   d  of the damper  35  extends above the damper attachment bracket  35 ′. A second portion  35   e  of the viscous damper  35  extends below the damper attachment bracket  35 ′ and through the damper anchor hole  132  (See  FIG. 11 ). 
     As shown in  FIGS. 7 and 8 , in this exemplary embodiment the cab attachment bracket  120  includes: an upper plate  121 ; a first side plate  122 ; and a second side plate  123 . The first side plate  122  is positioned closer to the C post  25  than the second side plate  123 . The upper plate  121 , the first side plate  122 , and the second side plate  123  are welded together as illustrated. The attachment bracket is welded to the rear cab panel  26  as illustrated in  FIGS. 3 ,  6  and  11 . A bracket brace  124  is welded to the top plate  121 , the first side plate  122 , and the C post  25  for additional structural support for the attachment bracket  120  (see  FIGS. 3 ,  6  and  11 ). As shown in  FIG. 8 , the side plates  122 ,  123  include substantially coaxial first and second cylindrical holes  122   a ,  123   a  having substantially equal diameters D 1 , D 2  and including chamfers  122   b ,  123   b  for ease of pin insertion. The first side plate  122  also includes a threaded flag attachment hole  125  for the flag  111  of the cab support pin  110 . 
     As shown in  FIGS. 9 and 10 , the travel limiting bracket  140  is, in this particular embodiment, welded to the rear mounting pad  130 , and includes a clearance hole  141  and threaded flag support holes  142 . The clearance hole  141  is sized to allow a desired amount of vertical, horizontal, and rotational movement for the shank  112  when the cab is supported by the rear viscous damper  35  during vehicle operations. As shown in  FIGS. 3 ,  6  and  11 , the rear support plate  150  may be welded to the second side plate  123  of the attachment bracket  120  and the rear cab panel  26 . The rear suspension anchor bolt  151  connects the viscous mount  35  to the rear support plate  150  and, thereby, to the cab attachment bracket  140  and the cab  110  via the threaded damper anchor hole  35   a.    
     As indicated in  FIGS. 3 and 6 , the shank  112  extends through the first cylindrical hole  122   a  of the cab attachment bracket  120 , the clearance hole  141  of the travel limiting bracket  140  and the second cylindrical hole  123   a  of the cab attachment bracket  120 . A snap ring  112   b  fits into groove  112   a  to hold the shank in place longitudinally. 
     As shown in  FIGS. 3 and 12 , when the cab  20  is suspended, i.e., when the rear support plate  150  is supported by the viscous damper  35 , the flag  111  of the cab support pin  110  is connected to the cab attachment bracket  120  via a flag anchor bolt  111   c . Thus, the cab support pin  110  may float with respect to the motion limiting bracket  140  but is fixed, with respect to the attachment bracket  120 . 
     In operation, to accomplish cab rotation, the cab support screws  111   d  are removed from the threaded flag support holes  142 , the flag anchor bolt  111   c  is removed from the threaded flag attachment hole  125  and the cab support pin  110  is rotated to align the cab support holes  111   a  with the threaded flag support holes  142 . The cab support screws  111   d  are then fitted through the cab support holes  111   a  and screwed into the flag support holes  142 . Finally, suspension anchor bolt  151  is removed from the threaded damper mounting hole  35   a  and the rear anchor hole  150 ′ and the cab  20  is rotated to the service position and held in place with the aid of a hydraulic cylinder (not shown). 
     To return the cab  20  to suspension for vehicle operation, the flag anchor bolt  111   c  is removed and the cab  20  is rotated from the service position to the operating position shown in  FIG. 12 . The suspension anchor bolt  36  is then fitted through the rear anchor hole and screwed into the threaded damper mounting hole  35   a . The cab support screws  111   d  are then removed, the flag is rotated to align the flag anchor hole  111   b  with the threaded flag attachment hole  125  and the anchor bolt  111   c  is fitted through the flag anchor hole  111   b  and screwed into the threaded flag attachment hole  125  to attach the flag  111  of the cab support pin  110  to first side plate  122  of the cab attachment bracket  120 . Finally, the cab support screws  111   d  are re-screwed into the flag support holes  142 .  FIGS. 12 and 13  illustrate views of the cab  20  and the cab support pin  110  when the cab  20  is in the work, or suspended position and the raised, or service, position, respectively. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.