Abstract:
Embodiments of the present invention generally relate to a rollover protection cab. In one embodiment, a rollover protection cab for a construction vehicle includes a structural frame defining cabin space for a vehicle operator. The structural frame is operable to substantially maintain the cabin space while withstanding a crushing load greater than or equal to twenty tons. The cab further includes a window; a door; a seat disposed in the cabin space; and controls for operating the vehicle disposed in the cabin space.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional App. No. 61/122,991, filed Dec. 16, 2008, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the present invention generally relate to a rollover protection (ROP) cab. 
     2. Description of the Related Art 
     Large off-road machines are employed for moving large quantities of earth, such as in building highways or dams, and are used in hauling ore as a part of mining operations. These large machines are required to travel at fairly fast speeds for efficiency and economy of operation and normally travel on temporary road surfaces or over terrain on which work is being preformed. For this reason, these large off-road machines are somewhat dangerous to operate since conditions do not permit construction of smooth, level roadbeds in most work situations. With the heavy loads, at fairly fast speeds and uneven terrain, the possibility of rollover of large machines, while relatively infrequent, nevertheless, is a safety concern of manufacturers and users of such machines. For this reason, chassis of these machines include a protective structure for the cab, commonly known as a rollover protection structure (ROPS). This requires extensive additional design and testing of the vehicle chassis. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention generally relate to a rollover protection (ROP) cab. In one embodiment, a rollover protection cab for a construction vehicle includes a structural frame defining cabin space for a vehicle operator. The structural frame is operable to substantially maintain the cabin space while withstanding a crushing load greater than or equal to twenty tons. The cab further includes a window; a door; a seat disposed in the cabin space; and controls for operating the vehicle disposed in the cabin space. 
     In another embodiment, a crawler includes an undercarriage and a main assembly. The undercarriage includes a lower frame; and two tracks. Each track includes a track frame coupled to the lower frame; and a track shoe supported by the track frame and movable around the track frame. The main assembly is supported by the undercarriage so that the main assembly may rotate relative to the undercarriage. The main assembly includes a main frame; a boom pivoted to the main frame; and a rollover protection cab fastened to the main frame. The cab includes a structural frame defining cabin space for an operator. The structural frame is operable to substantially maintain the cabin space while withstanding at least a substantial portion of a weight of the crawler. The structural frame is independent from the main frame. The cab further includes a window; a door; and a seat disposed in the cabin space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIGS. 1A-1D  are various views of an ROP cab, according to one embodiment of the present invention.  FIG. 1E  is a plan view of a control center of the ROP cab. 
         FIGS. 2A-2F  illustrate the structural frame of the cab. 
         FIGS. 3A-3B  illustrate an alternative ROP cab, according to another embodiment of the present invention.  FIGS. 3C-3D  illustrate an alternative ROP cab, according to another embodiment of the present invention. 
         FIGS. 4A and 4B  are views of an excavator, according to another embodiment of the present invention.  FIG. 4C  is a view of a jackhammer that may be used with the excavator instead of the shovel. 
         FIGS. 5A and 5B  illustrate the cab mounted on a cab actuator, such as a riser, according to another embodiment of the present invention.  FIGS. 5C and 5D  illustrate details of the riser. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1A-1D  are various views of an ROP cab  1 , according to one embodiment of the present invention. The cab  1  may include a structural frame  5 , one or more floor panels  11 , one or more windows  15   b,d,f,               ,ra,rb,rc,t , one or more body panels  20             ,r,b,d , control panel  20   c , mounting brackets  25 , door  30 , seat  35 , control center  100  (see  FIG. 1E ), and a climate control system  40 . The climate control system  40  may include an air conditioner and/or heater. The control center  100  (including the seat  35 ) may be disposed within a cabin space defined by the structural frame  5 . The body panels  20             ,r,b,d  may be plates and welded (i.e.,  20   b,d ) or fastened (i.e.,  20             ,r ) to the structural frame  5 . The control panel  20   c  may be fastened to the structural frame  5 .
     The structural frame  5  may be made from heavy-wall steel pipe and have adequate strength to withstand a crushing force, such as at least twenty tons, fifty tons, one hundred tons, or two hundred fifty tons. Alternatively, the structural frame  5  may be configured to withstand at least a substantial portion of the weight of a construction vehicle, on which the cab  1  is mounted. Additionally, the structural frame  5  may be configured to withstand the weight of the vehicle or the weight of the vehicle plus a safety margin. Alternatively, the structural frame  5  may be made from another alloy or metal or a composite, such as a fiber-resin composite. Alternatively, the structural frame  5  may be made to meet or exceed any one or more of the following standards: SAE J1040, ISO 3471, SAE J154, SAE J397, SAE J1043, SAE J1164, SAE J1194, and SAE J2194. 
     The crushing force may result from tipping or rollover of the construction vehicle on which the cab  1  is mounted. The structural frame  5  may withstand application of the crushing force from one or more directions, such as the force exerted on top of the cab  1 , the force exerted on the front of the cab  1 , and/or the force exerted on sides of the cab  1 . The structural frame  5  may deflect upon being loaded by a weight of the vehicle; however, the structural frame may substantially maintain the cabin space during loading, such as at least eighty percent, eighty-five percent, or ninety-percent. Alternatively, the structural frame  5  may be made from other structural shapes instead of pipe, such as I-beam, channel, angle, or rectangular (including square). 
     The structural frame  5  may be integral to the cab  1  so that the cab  1  requires no rollover protection from the vehicle&#39;s chassis. This independence allows for the cab  1  to be designed and tested separately from the vehicle, thereby freeing the vehicle design from having rollover structure to protect the cab. This independence may also allow the cab  1  to be modular with respect to an array of construction vehicles, including incorporation in newly designed vehicles or retrofit for existing vehicles. 
       FIG. 1E  is a plan view of a control center  100 . The control center  100  may include the operator&#39;s seat  35 , one or more hand-operable joysticks  105 , one or more consoles  102 ,  103 , one or more foot-operable pedals  106 , and a video display  110 . The consoles  102 ,  103  may include various pushbuttons and/or switches to control various functions of the vehicle. Alternatively, the consoles  102 ,  103  may be located overhead instead of adjacent the seat  35  or some of the pushbuttons and/or switches may be located adjacent to the seat and some overhead. The video display  110  may be a flat panel monitor, such as LCD or plasma. The video display  110  may display an operational status of the vehicle, such as video gauges, load graphs, and/or system messages. The control center  100  may further include a controller (not shown), such as a microprocessor, located behind the seat  35 . The controller may be in electrical, i.e., power and data, communication with the consoles  102 ,  103 , joysticks  105 , foot pedals  106 , and video display  110 . The controller may be in hydraulic and/or electrical communication with a manifold of the vehicle via conduits extending through the control panel  20   c.    
     The controller may include a load management system (LMS). The LMS may be a include a variety of sensors in communication with the controller to calculate and display boom angle, boom capacity, and/or the boom load. The LMS may include a database of boom capacities for various operating positions and surface grades. The LMS may alert the operator, with audio and/or visual warnings, when rated capacity is imminent, reached, and/or exceeded. 
       FIGS. 2A-2F  illustrate the structural frame  5  of the cab  1 . The structural frame  5  may include columns  6 , beams  7 , curved beams  8 , and elbows  9 . The structural frame  5  may be connected by welds. The columns  6 , beams  7 ,  8 , and elbows  9 , may be connected by butt-welds. The structural frame may further include one or more sub-frames, such as floor frame  10 , window frames  12   b,d,f,               ,ra,rb,rc,t , door frame  27 , body panel frames  18             ,r , climate control base  39 , and control panel frame  18   c . The sub-frames may be plates welded to the structural frame  5 . Openings may be cut out from the sub-frames before or after the sub-frames are welded to the structural frame  5 .
     The windows  15   b,d,f,               ,ra,rb,rc,t  may be made from a transparent polymer, ceramic, or composite, such as polycarbonate (PC), polymethyl methacrylate (PMMA), tempered glass, laminated glass, aluminium oxynitride, magnesium aluminate spinel, or aluminum oxide. The windows  15   b,d,f,             ,ra,rb,rc,t  may be mounted on the window frames  12   b,d,f,             ,ra,rb,rc,t  by an adhesive or fasteners. The windows  15  may be sufficiently impact-resistant to protect the operator from falling objects. The front window  15   f  may be curved to improve operator visibility forward and/or above the cab  1 . Some of the windows, i.e., the front window  15   f  and/or the window  15   ra  opposite the door  35 , may serve as an escape-hatch for the operator. These escape-hatch windows may have quick-release fasteners  310  (see  FIG. 3B ) to allow the operator to release the window after rollover and be adequately sized for the operator to climb through. Alternatively, the escape-hatch windows may be mounted so that the operator may detach the windows by a kick from the seat  35 .
     A seal  15   s  may be disposed on each of the window frames  12   b,d,f,               ,ra,rb,rc,t , the floor frame  10 , and/or the door frame  27  so that the cabin  1  is air-tight. A filter may be disposed on an inlet of the climate control system  40  to filter exhaust fumes. The climate control system  40  may also maintain positive pressure in the cab  1  to ensure that any leaks are from the cab  1  to the environment and not vice-versa. The cab  1  may further include an air or oxygen tank (not shown) so that if the vehicle falls in water, the operator may wear a mask in communication with the tank. The tank may store an amount of air or oxygen, such as one hour to twenty-four hours, to allow a rescue crew to retrieve the operator before drowning of the operator.
     The floor frame  10  may include angle or L-shaped beams having openings (i.e., nuts welded to holes formed therethrough) for receiving fasteners to retain the floor panels  11 . The floor panels  11  may be made from metal, alloy, or polymer. A doorway may be cut out from the door frame  27  for receiving the door before or after the frame is welded. Hinges (not shown) may be welded or fastened to the door frame  27 . The door frame  27  may include a plate and/or L-shaped beam welded to the structural frame  5 . 
     The mounting brackets  25  may be welded to the structural frame  5 . The mounting brackets  25  may have holes formed therethrough for receiving fasteners to retain the cab  1  to the vehicle. The fasteners may be conventional (i.e., bolts or threaded studs). The fasteners and mounting brackets  25  may be configured to retain the cab  1  to the vehicle during tip-over or rollover (i.e., have a similar design strength to the structural frame  5 ). The mounting brackets  25  may serve as the sole support from the vehicle&#39;s chassis or main frame so that the vehicle chassis or main frame may omit a separate structure for the cab, thereby reducing expense of the vehicle chassis design. 
     Alternatively, the fasteners may be frangible so that the cab  1  may detach from the vehicle upon a predetermined force exerted on the cab  1  during tipping or rollover of the vehicle. Configuring the cab  1  to separate from the vehicle during tipping or rollover may be beneficial so that the operator is not trapped within the cab  1  after the vehicle has rolled over, such as if the door  30  is sandwiched between the machine and the ground and/or the structural frame deforms and wedges the door shut. The predetermined force necessary to shear the frangible fasteners may be a ratio of the vehicle&#39;s weight, such as one-tenth to three-quarters or one-quarter to one-half of the vehicle&#39;s weight to ensure that the cab  1  separates from the vehicle before the entire weight of the machine rests on the cab  1 . 
       FIGS. 3A and 3B  illustrate an alternative ROPS cab  300 , according to another embodiment of the present invention. The cab  300  may be similar to the cab  1  with the addition of a falling object protection shield (FOPS)  302 . The FOPS  302  may be curved to correspond to the curved front window. The FOPS  302  may include a frame  318 , one or more plates  312   u ,           , one or more pads  316 , and one or more fasteners  310 . The FOPS  302  may include a pad  316  and fastener  310  adjacent each corner of the frame. The plates  312   u ,          may be made from any of the materials discussed above for the windows. The plates  312   u ,          may each be bonded to the frame  318  and the pads  316  may be bonded to the plates  312   u ,          A hole may be formed through each pad  316  and plate  312   u ,          for receiving a respective fastener  310 . A corresponding hole may be formed through the front window frame  12   f  for receiving each fastener. Each fastener  310  may include a shaft  311 , washers  319   i,o , a spring  313 , and pins  320   i,o . Each pin  320   i  may be disposed in the cabin space and each pin  320   o  may be externally disposed. The washer  319   i  may be disposed between the pin  320   i  and an inner surface of the window frame  12   f  and the washer  320   o  may be disposed between the external pin  320   o  and the pad  316 . The spring  313  may be disposed between an outer surface of the window frame  12   f  and an inner surface of the respective plate  312   u ,         , thereby biasing the FOPS  302  away from the window frame  12   f . The fasteners  310  allow for the operator to quickly release the shield  302  from the cab by pulling each pin  320   i  from the shaft  311 .
       FIGS. 3C and 3D  illustrate an alternative ROPS cab  350 , according to another embodiment of the present invention. The cab  350  may be similar to the cab  1  with the addition of a FOPS  362 . The FOPS  362  may be curved to correspond to the curved front window. The FOPS  362  may include a grating of curved beams, such as pipe, rods, or expanded metal or alloy, joined at each longitudinal end by beams  363 , such as pipe or rods. The curved beams may be spaced apart to allow visibility therethrough by the operator. The FOPS  362  may further include an actuator  365  rotationally coupled to one of the braces and mounted to the cab  300 . The actuator  365  may include a hydraulic or electrical motor to pivot the FOPS  362  between an engaged position as shown and a disengaged position. A switch may be disposed in the cab  350  to allow the operator to operate the actuator  365  between the positions. The operator may desire the FOPS  362  to be disengaged during jobs that have a minimal risk of falling objects to obtain better visibility and the FOPS to be engaged during jobs that have a substantial risk of falling objects. Alternatively, the actuator may be omitted and the FOPS  362  may be manually actuated between the positions. Alternatively, the FOPS  362  may be fixed to the cab in the engaged position. 
       FIGS. 4A and 4B  are views of a crawler, such as an excavator  400 , according to another embodiment of the present invention.  FIG. 4C  is a view of a jackhammer  495  that may be used with the excavator  400  instead of a shovel  440 . The excavator  400  may include a main assembly  450   a  mounted on an undercarriage  450   b  so that the main assembly  450   a  may rotate relative to the undercarriage  450   b . In the position illustrated, a longitudinal axis L mf  of the main assembly  450   a  is perpendicular to a longitudinal axis L uc  of the undercarriage  450   b.    
     The main assembly  450   a  may include a main frame  405 , the cab  300 , a boom assembly  420 , a counterweight  445 , and an engine  447 . The main frame  405  may have a front  405   a  and a back  405   b  distal from the front  405   a . The boom assembly  420  may be pivoted  420   p  to the main frame at or near the front  405   a . The cab  300  may be fastened to the main frame  405  via the mounting bracket  25 . Alternatively, the cab may be fastened to the main frame via a hydraulic or electrical cab actuator (see  FIGS. 5A-5D ). The cab actuator may allow the cab to pivot and/or elevate relative to the main frame  405 , thereby allowing operator adjustment to improve visibility. For example, the cab actuator may pivot the cab so that the curved front widow faces above the excavator  400  for demolition work. Alternatively, the cab  1  or  350  may be used with the excavator  400  instead of the cab  300 . 
     The boom assembly  420  may include a boom  420   a  and an arm or stick  420   b  pivoted to the boom  420   a . One or more first PCAs  425   a  may be pivoted to the main frame at or near the front  405   a  and pivoted to the boom  420   a  for articulating the boom  420   a  relative to the main frame  405 . A second PCA  425   b  may be pivoted to the boom  420   a  and the stick  420   b  for articulating the stick  620   b  relative to the boom  620   a . A bucket  440  may be pivoted to the stick  420   b . A third PCA  425   c  may be pivoted to the stick  420   b  and the bucket  440  via a linkage for articulating the bucket  440  relative to the stick  420   b . Alternatively, a jackhammer  495  may replace the shovel  440  for demolition work. Alternatively, a grapple, shear, or pulverizer may replace the shovel  440 . Alternatively a demolition boom assembly may replace the boom assembly  420 . Alternatively, the boom assembly  420  may be removed and an adaptor fastened to the boom  420   p  and first PCA pivots to allow a crane boom to be pivoted to the adaptor, as discussed and illustrated in U.S. Pat. No. 6,003,252, which is herein incorporated by reference in its entirety. Alternatively, the adaptor may accept a pipelayer (i.e., A-frame boom) so that the pipelayer boom may be pivoted to the main frame using the adaptor. 
     The counterweight  445  may be vertically supported and longitudinally coupled to the main frame  405  at the back  405   b . Housed near the back  405   b  of the main frame  405  may be the engine  447 . The engine  447  may drive a hydraulic pump (not shown) and a generator or alternator (not shown) for providing hydraulic or electrical energy to components, such as the cab  300 , the PCAs  425   a - c , and the track rollers  480  via a manifold (not shown). Associated hydraulic and/or electrical circuitry (not shown) interconnecting these components may also be provided. The engine may be a diesel engine or an alternative fuel engine. Examples of alternative fuel engines include diesel-electric hybrid and hydrogen fuel-cells. The diesel-electric hybrid may use a smaller diesel engine and a bank of batteries (not shown) which would allow operation of the excavator  400  without operation of the diesel engine. 
     Rotation of the main assembly  450   a  relative to the undercarriage  450   b  and support for the main assembly  450   a  by the undercarriage  450   b  may be provided by a rotary drive mechanism (not shown) and a bearing (not shown). The rotary drive mechanism may include a hydraulic or electric motor (not shown) attached to the main frame  405  and rotationally coupled to a pinion (not shown) which meshes with a gear (not shown) rotationally coupled to the undercarriage  450 . Operation of the motor may rotate the main assembly  450   a  relative to the undercarriage  450   b . The rotary drive mechanism may further include a slew lock mechanism (not shown) for selectively rotationally coupling the main assembly  450   a  relative to the undercarriage  450   b . The slew lock mechanism may include a gear tooth (not shown) selectively engageable with the gear via operation of a hydraulic cylinder or electic motor (not shown) and a proximity switch to verify engagement of the tooth with the gear. Engagement of the gear with the tooth rotationally couples the main assembly  450   a  to the undercarriage  450   b . Verification of engagement by the proximity switch also prevents operation of the motor. 
     Alternatively, the slew lock mechanism may include a disk (not shown) incorporated in the motor and a retaining mechanism for retaining the disk. The slew lock mechanism is such that when the rotary motor is stopped, the disk is retained by the retaining mechanism to fix a rotor of the motor so as not to rotate, and when the motor is started, the disk is hydraulically or electrically disengaged from the motor, thereby freeing the rotor. 
     The undercarriage  450   b  may include a lower frame  460  attached to the bearing and two track assemblies  475 , each fastened to the lower frame  460 . Each of the track assemblies  475  may include a track frame  482  and one or more rollers  480   a,b , such as sprockets, operatively coupled to a track shoe or belt  485 . The track shoe  485  may extend around the track frame  482  and be movable relative to the track frame. The rollers  480   a, b  may be supported by the track frame  482  so that the rollers may rotate relative to the track frame. One of the rollers  480   a, b  may be a drive sprocket and the other an idler roller. A rotor of an electric or hydraulic track motor (not shown) may be rotationally coupled to the drive sprocket and a housing of the track motor may be attached to the track frame. A conduit, such as an electrical cable or hydraulic hose, may extend from the main frame  405  to the track motor. The conduit may be connected to the track motor by a quick-connect fitting. Operation of the track motor may move the track shoe  485  relative to the track frame. 
     Alternatively, each of the track motor housings may be attached to the lower frame  460  and each rotor thereof rotationally coupled to a respective drive roller via a removable shaft. The shaft may be removably rotationally coupled at the track motor. Alternatively, each of the track assemblies  475  may be attached to the lower frame  460  by one or more telescoping axles (not shown). The telescoping axles may extend to provide a wide footprint for operation and retract to provide a narrow footprint for transportation. 
     To facilitate disassembly of the excavator  400  for transport and re-assembly of the excavator  400  for delivery to the next job site, each of the track assemblies  475  may include one or more lugs attached to the track frame  482 . Each of the lugs may include a hook and a hole. Each of the lugs may be received in an opening of a bracket assembly attached to the lower frame  460 . The bracket assembly may include two plates spaced apart to define the opening, each plate attached to the lower frame  460 . Fasteners (i.e., a bolt or a pin) may each be disposed through corresponding holes in the plates. To fasten each track assembly  475  to the lower frame  460 , the fastener may be removed and the hook may be engaged with the fastener and the fastener may then be inserted through holes in the plates and the hole and then locked to the track frame by a fastener (i.e., a nut or a clip). The track conduit may then be connected to the track motor by the quick-connect fitting. Alternatively, the lug may be attached to the lower frame  460  and the bracket assembly may be attached to the track frame  482 . 
     To further facilitate disassembly for transport and re-assembly for delivery of the excavator  400 , one or more outriggers  465  may be pivoted to the lower frame  460 . Each outrigger  465  may include a first arm, a second arm, a third arm, and a pad. The first arm may be pivoted relative to the lower frame  460 . The second arm may be pivoted to the first arm and retractable within the first arm. The third arm may be retractable within the second arm. The pad may be pivoted to the third arm. The outriggers  465  may be operable between an extended position and a retracted position. 
     To remove the track assemblies for transportation, the outriggers  465  may be extended to support the main frame. The boom assembly  420  may be used to hoist each track assembly  475  and load the track assembly on to a low-boy trailer. Once the track assemblies are loaded, a second low-boy may be backed underneath the excavator and the outriggers may then lower the excavator onto the second low boy. The boom assembly may then be folded. Alternatively, the excavator may be self-loaded on to only one low-boy. 
     Additionally, the cabs  1 ,  300 ,  350  may be used with other off-road vehicles, such as any type of crawler, such as cranes, side-booms, bulldozers, forestry carriers, waste handlers, or pipelayers. Additionally, the cabs  1 ,  300 ,  350  may be used for on-road or off-road vehicles, such as wheeled vehicles, such as tractors, loaders, skid-steers, forklifts, backhoes, articulated haulers, scraper haulers, motor graders, pavers, or compactors. 
       FIGS. 5A and 5B  illustrate the cab  300  mounted on a cab actuator, such as a riser  500 , according to another embodiment of the present invention.  FIGS. 5C and 5D  illustrate details of the riser. Alternatively, the riser  500  may be used with either of the cabs  1 ,  350 . As shown, the cab riser  500  is mounted on a test stand  501 . The cab riser  500  may be fastened to the main frame  405  and operable to vertically move the cab  300  between a raised position and a lowered position relative to the main frame  405 . In this manner, the operator may adjust the height of the cab relative to the main frame to obtain optimum visibility. The cab riser  500  may raise the cab a maximum distance from a bottom of the main frame, such as one to six feet, such as about two and one-half feet. 
     The cab riser  500  may include a base  505 , a frame  510 , and a piston  515   p  and cylinder  515   c  assembly (PCA). The frame  510  may be moved relative to the base  505  by the PCA  515   p,c . The frame  510  may include one or more guide sleeves  511  and one or more brackets  512 ,  513 . The frame members  511 - 513  may each be fastened and/or welded together or integrally formed. Each guide sleeve  511  may be fastened to the PCA  515   p,c  via the bracket  512 . The bracket  512  may be fastened or welded to the cylinder  515   c . The bracket  25  of the cab  300  may be fastened to the frame bracket  513 . The PCA  515   p,c  may be operable to raise or lower the frame  510  (and cab  300 ) relative to the base  505  (and main frame  405 ) via injection and/or removal of hydraulic fluid via one or more ports  515   h . Alternatively, an electric motor may be used to raise or lower the base  505  instead of the PCA  515   p,c . The PCA  515   p,c  may be in fluid communication with the hydraulic system of the excavator  400  via a hydraulic conduit, such as a hose (not shown). The cab riser  500  may also include a lock (not shown) operable to retain the base  505  at a selected height. One or more guide posts  525  may be fastened to the base  505  via brackets  526 . Each of the guide sleeves  511  may be laterally coupled to a respective guide post  525  and free to vertically slide along the respective guide post  525 . The piston  515   p  may be fastened to the base  505 . Upon removal of the test stand  501 , the base  505  may be fastened to the main frame  405 . 
     The riser  500  may further include one or more conduits  530 . The conduits  530  may each house one or more hydraulic hoses and/or electric cables (not shown) extending between the excavator manifold and the cab  300 . The conduit  530  may also house the hydraulic hoses extending between the manifold and the PCA  515   p,c . Each conduit  530  may include a first end fastened to the base  505  via bracket  532  and a second end fastened to the cab  300  via bracket  531 . Alternatively, the second end may be fastened to the frame  510 . Each conduit  530  may include a plurality of links  533 , each link pivoted to other links  533  so that the conduit  530  may accommodate vertical movement of the frame  510  relative to the base  505 . Each link  533  or every other link may include a top and bottom rung to house the cables and/or hoses, thereby protecting them from entanglement in the riser  500 . The links  533  may be made from a metal or alloy, such as steel. Alternatively, the conduit may be a single member made from a flexible material, such as a polymer. Alternatively, the cab  300  may only be in electrical communication with the manifold via wireless power and data couplings, such as inductive couplings and/or RF transceivers. Alternatively, the PCA  515   p,c  may be inverted. 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.