Abstract:
A self-propelled material handler has a pivotally mounted boom on a frame, and a cab that is positioned adjacent the side of the boom. The cab has an operator&#39;s entrance and exit opening on a side of the cab, that is positioned to permit an operator to enter and exit the cab and sit on a seat in the cab. A lateral restraint bar is mounted between the seat and the cab opening, and is movable to a working position where it obstructs the cab opening so that portions of the operator cannot be moved outwardly through the cab side opening from the interior, and which pivots to a raised position to permit an operator to pass through the cab opening. When the restraint bar moves away from its working position, a signal is provided to disable machine controls.

Description:
The present application is based on and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/429,755, filed Nov. 27, 2002, the content of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a lateral restraint system in a cab on a material handler or TOOL CARRIER that moves along side an operator&#39;s seat, and is particularly useful to restrain an operator when there is no side door on the cab operator access opening. The lateral restraint system includes a restraint bar and an arm rest on the exterior side of the operator and is movable from a working, operator and leg restraining position to a raised position. The restraint bar pivots upwardly so in its raised position it is out of the way to permit egress and entrance to the cab and the system has a sensor to disable controls when not in a working position. It is preferable that the operator wears a seat belt during operation to avoid injury. 
     Telescoping boom tool carriers or material handlers that have telescoping booms mounted onto a mobile platform are well known. These machines generally will have a pivoting boom along one side of the machine frame, with an operator&#39;s cab that is positioned on the frame and is laterally positioned relative to the boom. The cab has a side opening for the operator to get in and out of the cab on the opposite side of the cab from the boom. While many of these cabs are provided with doors over these openings, there are times when it is desirable to not have a door. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a movable bar acting as a lateral operator restraint and has an arm rest portion for operator comfort. The pivoting restraint bar is mounted on the side of an operator&#39;s cab of a machine such as a material handler, adjacent to the operator access door opening, and positioned to the exterior side of the operator&#39;s seat. The operator restraint bar is oriented for movement from a working position wherein it is located to block lateral movement of the operator and the operator&#39;s foot and leg in a direction toward the exterior of the cab, and which can be manually moved upwardly out of the way easily for operator access and egress from the cab. As shown, the restraint bar is pivoted by a mounting linkage or other support arrangement can be used. 
     The lateral operator restraint system is primarily useful when there is no door provided for the cab operator access opening, to avoid involuntary or voluntary outward movement of the operator or of the operator&#39;s foot and leg that is adjacent to the cab opening. Moving the foot and leg outside of the cab or canopy is restrained. 
     The manually operated restraint bar is provided with a spring to hold it in its working position, and also to hold it in its open position. The restraint bar is provided with a sensor or switch that senses when the restraint bar is not in its working position (and thus the operator is not present) to permit the machine controls to be disabled through an interlock control system. When the restraint bar moves a selected distance from its working position toward the raised or non-working position, the sensor provides a signal to the interlock circuit to disable the machine controls so the material handler machine cannot be moved or operated and preferably the brake is applied. Therefore, the machine can be operated only when the restraint bar is in its working position, meaning an operator is present. 
     Normally the material handlers use a joystick control, and all of the functions that are controlled by the joystick will be disabled by the interlock when the restraint bar is moved to its raised or open position. This means that the boom cannot be lifted, lowered, or telescoped, and the dump and crowd controls for attachments, and the auxiliary controls for the attachment cannot be utilized. The transmission and frame leveling functions also can be disabled so that the machine could not be moved, and at the same time brakes for the machine can be enabled holding the machine stationary when the operator restraint bar and arm rest portion is raised. 
     The restraint bar is very simply operated. A retainer for holding the lower portion of the restraint bar in place when in its working position is provided. It is used with an armrest pad of suitable design in the lowered or working position. Bumpers on the cab surfaces for stopping the restraint bar when it is moved to its raised position are also provided. The restraint bar is out of the way, and shielded by the cab panels when it is in its open position. 
     As shown, the sensor system for providing a signal to the interlock circuit for the material handlers controls, is a Hall effect sensor. The sensor is mounted stationarily on the door post or side panel of the machine cab and a magnet is mounted to move with the restraint bar mount, so that when the restraint bar has moved a selected distance away from its working position, the controls to the material handler will be completely disabled. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a material handler including a pivotal boom and having a restraint bar made according to the present invention installed therein; 
         FIG. 2  is a side elevational view of the cab portion of the material handler of  FIG. 1  with the restraint bar in its working position; 
         FIG. 3  is a side view similar to  FIG. 2  with the restraint bar in its raised or open position; 
         FIG. 4  is a front elevational view of the restraint bar assembly in its raised position; 
         FIG. 5  is a side view from the interior of the cab showing the restraint bar system and the spring for holding the positions of the restraint bar in an enlarged view; 
         FIG. 6  is a schematic perspective view of a mounting support for the restraint bar with parts removed for sake of clarity; 
         FIG. 7  is a view of an interior of a mounting hub for the restraint bar which mounts onto a pivot shaft shown in  FIG. 6 ; 
         FIG. 8  is a perspective view of a retainer used with the lower end of the restraint bar when it is in its working position; and 
         FIG. 9  is a schematic diagram of a typical control and interlock system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In  FIG. 1 , a material handler machine indicated generally at  10 , as shown, has a main frame  12 , and drive and steering wheels  14 A and  14 B. The material handler  10  can have two wheel steer, crab steer, or four wheel steer, and generally speaking all four wheels that are shown are powered, for normal operation. 
     The material handler frame  12  has a telescoping boom  16  mounted thereon about a pivot at the rear of the frame (not shown) and the boom extends forwardly and overlies the right hand side of the frame. It can be seen that the boom  16  is to the inside of the wheel  14 A on the right hand side of the machine oriented with the operator looking forwardly. 
     The frame  12  also has an operator&#39;s cab or canopy shown generally at  18 , which is supported on the frame  12  in a normal manner. In a telescoping boom material handler, the side of the cab adjacent to the boom is generally closed with windows or screens for visibility, so that an operator cannot move into the path of the boom as the boom pivots. 
     The operator cab  18  has an operator&#39;s seat  20 , as can be seen which includes a seat cushion  20 A and a back rest  20 B. A seat belt  20 C is also provided. The cab  18  has an operator opening  22  on the side opposite from the boom that permits the operator to move in and out onto the seat  20 . The opening  22  can be covered by a door in some instances, but a door may not be provided, and also climate conditions may make it desirable to not have a door. 
     The operator cab or compartment has a floor  24  on which an operator&#39;s feet can rest (see FIG.  2 ) and an operator  25  seated on the seat cushion  20 A is in a position to operate a joystick control  26 , or other type of control systems which controls the various functions of the machine including, as will be shown schematically, the drive transmission, and the various actuators for operating the boom  16 , and auxiliary equipment. The material handler has an engine (not shown) located in an engine compartment, for providing power to hydraulic circuits that include valves that are controlled by the joystick  26 . 
     When the cab lateral opening  22  is unobstructed, as seen, the operator&#39;s feet and legs  32 , which are illustrated in  FIG. 2 , for the operator seated on the seat cushion  20 A, can be moved to the exterior of the cab  18 , where they can be struck by objects or equipment that may be operating in the vicinity. In order to provide a lateral operator restraint, to restrain movement out through the opening  22  when working, a restraint and operator presence sensor bar assembly  30  is provided. The restraint bar  30  blocks the cab opening  22  when down, or in its working position and enables the machine controls in that position. The restraint bar will obstruct outward movement of the exterior foot and leg of the operator as shown the left leg and foot  32 . The operator&#39;s body is also blocked or restrained from sliding off the seat and out the opening  22 , as can be seen in  FIGS. 1 and 2  by a horizontal arm rest portion. 
     The operator restraint bar  30  has a mounting hub assembly  33 , which includes a support frame  34  shown in  FIG. 6  at  34  that is secured to an upright post  36  of the operator&#39;s cab or to the side panel or wall of the cab. This support frame  34  has a downwardly depending support leg  38 , as can be seen, and mounts a fixed pivot shaft  40  that protrudes laterally, as can be seen so that it pivotally mounts a pivoting or rotating hub  42  ( FIGS. 4 ,  5 , and  7 ). The hub  42  can be held onto the shaft  40  with a nut and washer assembly at the outer end of the shaft. The rotating hub  42  as shown in  FIG. 7  has a bore  44  that fits over the shaft  40 , and also has a flange  46  that will surround a central chamber on the inside of an end plate  50 . The hub  42  extends inwardly from an outer plate  50  of the hub  42 . The plate or wall  50  is spaced from the surface of the mounting frame  34 . 
     Movable hub  42  mounts the restraint bar  52 , which is fixed to rotating hub  42 , is part of assembly  30 , a pipe that is bent to include a generally horizontal pipe arm rest portion  52 A with a pad  92  thereon when the restraint bar is in its lowered or working position; a forwardly and downwardly inclined portion  52 B that is spaced from the operator&#39;s seat cushion, and blocks the outward movement from the space ahead of the operator&#39;s seat. The space  49  is the leg space between the seat  20  and the front panel  51  of the cab. The bar or pipe portion  52 B is in a position to interfere with any lateral movement of the outer foot and leg  32  of the operator  25  toward the outside. 
     The arm rest portion  52 A also restrains lateral outward movement of the operator&#39;s body and provides for operator comfort. The bar or pipe  52  has an inwardly tapering portion  52 C that extends down from portions  49  across the lower portions of the operator&#39;s cab across the space  49 , again to the exterior of an operator&#39;s foot and leg  32 . The portion  52 C has a short bent retainer end  52 D formed on the restraint bar. The retainer end  52 D, as can be seen in  FIG. 8 , is parallel to the floor  24  and is received in a retainer bracket  54  that is secured to the seat support  56  and receives the end portion  52 D of the restraint bar pipe when the restraint bar is in its lowered or working position. 
     The hub  42  has an outwardly projecting ear  60 , that is used for connecting a spring end  62 , that forms part of a telescoping center slide and guide member  64  for a compression spring  66 . The spring  66  acts against a pivot block  68  that is pivoted to the upright post  36  of the cab, and is used to provide a spring force that will bias the restraint bar assembly  30  and thus pipe  52  toward its working position. 
     As shown in  FIG. 5 , in solid lines, the hub  42  and ear  60  are positioned so the line of force from spring  66  will go “over center” relative to the pivot axis of hub  42  as the restraint bar is raised in the direction as indicated by the arrow  70  (FIG.  5 ), toward its open position that is shown in FIG.  3 . When the restraint bar has moved to its substantially vertical position as indicated in dotted lines in  FIG. 5 , the spring force from spring  66  will cause the restraint bar to pivot rearwardly in the direction of arrow  70 , and move against its stopped position, as shown in FIG.  3 . 
     In  FIG. 3 , a portion of the cab side wall has been broken away to show a rubber bumper  74  against which the restraint bar pipe  50  will rest when it is moved toward its raised position. It can be seen that the restraint bar is out of the way when it is in its open position, with the pipe sections recessed behind the edges of the cab. The pipe  50  does not interfere with any movement of the operator when open. 
     It can be thus seen that the restraint bar be manually moved by grasping a handle  74 , which also serves as an additional lateral restraint, and then lifting the bar against the force or spring  66  as indicated by the arrow  70  in  FIG. 5  until the spring goes over center, and then the spring  66  will urge the restraint bar assembly  30  to its fully raised or open position. 
     More than one spring can be used, and the spring can be a tension spring, or a gas spring, or even a suitable elastomeric spring. Other types of retainers for retaining the bar in its lowered position and in its raised position can be used. 
     The restraint bar assembly also serves the function of disabling the controls to the material handler, when it is in its raised position making it necessary to lower the restraint bar before operating the machine. In order to achieve this, a sensor that senses the position of the restraint bar pipe  52  is utilized. The sensor can be of any desired type, but a Hall effect sensor is the preferred form shown. The Hall effect sensor  76  is fixed to the support frame  34  (FIG.  6 ), and is positioned relative to a magnet  78  shown in  FIG. 7 , that is attached to the wall  50  of the hub  42 , so that when the restraint bar is very close to its working position, the Hall effect sensor will sense the magnetic field at the selected restraint bar position and enable a joystick control circuit to be operated. When the restraint bar assembly  30  is raised a short distance, for example with the end  52 D raised up from the floor  24 , the magnet  78  will move sufficiently far from the sensor  76  so that the joystick control circuit will be disabled, and the machine and its components cannot be operated. A brake also can be applied when the signal is sensed. The sensor that senses the working portions of the bar can be used with only the arm rest portion, or shorter sections of pipe, to effectively permit operations only when an operator has lowered the restraint bar. 
       FIG. 9  shows a schematic diagram of this arrangement including the Hall effect sensor  76 , that is connected to the joystick or machine control circuit  80 . The control circuit  80  which as shown is a joystick control, controls numerous functions of the machine. When a desired signal is provided by a sensor  76 , the machine control or interlock circuit will lock out the transmission  82 ; the boom telescoping cylinders  84 ; the boom pivot cylinder  86 ; the tilt cylinders (they are used for auxiliary equipment  88 ). The conventional transmission used has a circuit that actuates brakes when it is in neutral, after a time delay. When the transmission is locked out, by the sensor signal the transmission acts as if it is in neutral and the control for the transmission will actuate the brake  90  that is provided on the machine after about a one second time delay. Hydraulic auxiliary functions  89  can be locked out and if provided, and if desired, a frame leveling circuit  91  can be disabled. Many of these components are controlled conventionally by the machine control circuit, operated as shown with the joystick  26  by the operator. Of course, the items or functions that are disabled can be one or more of any type of operation which should not be operated when the operator is not present. 
     The lateral restraint bar assembly  30 , therefore, is positioned between the open lateral side of the cab and the operator&#39;s seat, and is movable to a raised position. As shown, the bar assembly  30  is pivoted about a horizontal axis at a suitable location using a post or other frame member from the cab so that when it is raised it will be retracted up to the periphery of the opening for the cab and out of the way, but when lowered, it will provide a barrier for the feet and legs of an operator, as well as the portions of the operator&#39;s body above the seat, to restrain lateral movement out through the cab opening either inadvertently or intentionally. The arm rest portions restrain the operator&#39;s body from movement out the cab opening when in its working position. 
     The restraint bar  52  is retained in its two positions with a single spring as shown that will go over center so that in portions of the pivoting action it will urge the restraint toward its working position, and serve to retain it in that position during use, but which will then go over center as the restraint bar is pivoted toward its open position, and will hold the restraint bar in its open position. 
     The sensor that is used as shown is a Hall effect sensor so that it is not a contact type sensor and has great reliability. Other sensors for providing a disabling/enabling signal can be used, so long as they will operate reliably under working conditions. The sensor is also enclosed within the hub  42 , and the flange  46 , so that it is protected from damage. 
     Spring  66  has sufficient force so that it will hold the restraint bar assembly  30  in its working position even in rough terrain operations, and it will hold it sufficiently lightly so that the sensor will not be accidentally moved sufficiently to disable the machine control circuit. The spring also will hold the restraint bar assembly  30  in its upper or open position, while not exerting excessive force. An operator can lift and lower the bar assembly quite easily. 
     The restraint bar can be covered with a suitable foam or elastomeric material for comfort, and of course the arm rest  92  can be formed in any desired manner. 
     Disabling the control circuits also insures that the operator lowers the restraint bar in order to operate the machine&#39;s controls. 
     The operator restraint bar may be designed in various ways, for example by extending forwardly to the dash board  51 , or end part way up on the seat support. It can operate as an arm rest that blocks substantial lateral leg movement as well. It also can be mounted for movement between its lower and raised position by links, sliding connections and other mounting devices. Pivoting the lateral restraint bar is a convenient mounting arrangement. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.