Abstract:
An operator&#39;s station for a machine having at least two stations comprises a seat mounted to swivel between at least a first position and a second position, at least first and second windshield portions disposed generally opposed or at an angle to one another and generally corresponding to the first and second positions, and at least first and second windshield wipers movably mounted to selectively sweep the first and second windshield portions, respectively. At least one control device selectively renders the first windshield wiper selectively operable when the seat is disposed in the first position and inoperable when the seat is disposed in the second position.

Description:
TECHNICAL FIELD 
     This patent disclosure relates generally to an operator station of a machine, and, more particularly, to a windshield wiper control arrangement for an operator station of a machine. 
     BACKGROUND 
     In the forestry industry, it is common for trees to be cut down in the woods and then hauled to a central collection point for further processing. One type of machine used for loading and transporting logs is typically referred to as a log forwarder or, simply, a forwarder. A forwarder typically includes a frame that can be unitary or articulated in one or more locations and is supported on a plurality of wheels or other ground engaging members. An operator station or cab is mounted onto a portion of the frame. The operator cab typically includes a seat that is mounted to swivel between a forward facing position from which the operator can drive the forwarder, and one or more generally rearward or sideward facing positions from which the operator may operate an articulated arm or boom to load previously cut logs into a payload portion of the forwarder for further transport. 
     Forwarders often operate in heavily forested areas, and areas where dirt and debris may collect on one or more of the machine windshields. Rain, snow, condensation or debris may cause wear to the windshield surface over time, which can be a particular concern if the windshield is formed of a plastic material. As a result, it is desirable to minimize operation of such wipers, particularly if not all of the windshields are in use at a given time. Moreover, in forwarders, controls are typically located near the windshields themselves. Accordingly, the operator must reach to the individual wiper controls to activate the wipers, distracting the operator from the other machine controls. 
     U.S. Pat. No. 5,734,243 discloses a vehicle that includes right and left side driver stations with dual operator controls for the wiping mechanism. The &#39;243 patent additionally provides a selector means that is operative to provide use of one control to the exclusion of the other so that the driver can operate the wiping mechanism, regardless of which of the driver stations the driver is using. 
     The present disclosure is directed to overcoming one or more of the problems and shortcomings of the art as set forth above. 
     SUMMARY 
     The disclosure describes, in one aspect, an operator&#39;s station comprising a seat mounted to swivel between at least a first position and a second position, and at least first and second windshield portions disposed generally opposed or at an angle to one another and generally corresponding to the first and second positions. At least first and second windshield wipers are movably mounted to selectively sweep the first and second windshield portions, respectively. At least one control device selectively renders the first windshield wiper selectively operable when the seat is disposed in the first position and inoperable when the seat is disposed in the second position. 
     In another aspect, the disclosure describes a machine comprising a frame, at least two ground engaging members supporting the frame, and an operator&#39;s station disposed on the frame. The operator&#39;s station includes a seat mounted to swivel between at least a first position and a second position. At least first and second windshield portions are disposed generally opposed or at an angle to one another and generally corresponding to the first and second positions. Each windshield portion includes an outside surface. At least first and second windshield wipers are movably mounted to selectively sweep the first and second windshield portions, respectively. At least one control device selectively renders the first windshield wiper selectively operable when the seat is disposed in the first position and inoperable when the seat is disposed in the second position. 
     In yet another aspect, the disclosure provides a method of operating an operator&#39;s station that includes the steps of disposing the seat in a first position generally facing a first windshield portion that includes at least a first windshield wiper disposed to selectively sweep an outside surface of said first windshield portion, swiveling the seat to a second position generally facing a second windshield that includes at least a second windshield wiper disposed to selectively sweep an outside surface of said second windshield, the first and second windshields being disposed in different planes, and actuating at least one control device as the seat swivels to render the first windshield wiper selectively operable when the seat is disposed in the first position and inoperable when the seat is disposed in the second position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  and  FIG. 2  are outline views from different perspectives of a log forwarder in accordance with the disclosure. 
         FIG. 3  is an enlarged, fragmentary, schematic plan view of the operator station of the log forwarder of  FIGS. 1 and 2  broken away to show the seat assembly. 
         FIG. 4  is a perspective view of a seat assembly for use in the log forwarder illustrated in  FIG. 1  and  FIG. 2 , in accordance with the disclosure. 
         FIG. 5  is an enlarged fragmentary perspective view of the mounting assembly for the seat assembly of  FIG. 4 . 
         FIG. 6  is a further enlarged fragmentary perspective view of the mounting assembly of  FIG. 5 . 
         FIG. 7  is a schematic diagram illustrating the control arrangement for operation of the wipers of the log forwarder of  FIGS. 1-3 . 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure relates to a control arrangement for a wiper mechanism for a machine that includes workstations wherein the operator&#39;s support is pivoted between different positions. The term “machine” as used in this disclosure may refer to any machine that performs some type of operation associated with an industry such as mining, construction, farming, transportation, or any other industry known in the art wherein the operator&#39;s support pivots to varied positions. For example, the machine may be a forwarder, a backhoe, a bi-directional agricultural tractor, or the like. Moreover, an implement may be connected to the machine. Such implements may be utilized for a variety of tasks, including, for example, loading, compacting, lifting, brushing, and include, for example, arms, booms, buckets, compactors, forked lifting devices, brushes, grapples, cutters, shears, blades, breakers/hammers, augers, and others. 
     Two outline views from different perspectives of a machine  100  are shown in  FIG. 1  and  FIG. 2 .  FIG. 1  is a side view of the machine  100  and  FIG. 2  is a three-quarter view from the rear. In the illustrations of  FIG. 1  and  FIG. 2 , the machine  100  is a forwarder  102 . In the illustrated forwarder  102  includes an articulated frame  104  having an engine frame portion  106  and a payload frame portion  108  connected to one another at a pivot joint  110 . In an alternate embodiment, the frame  104  may be a rigid frame with no articulated connections between portions thereof or, alternatively, with more than one articulated joint connecting three or more frame portions to one another. Each of the engine frame portion  106  and payload frame portion  108  includes ground engaging members  112 , here, four driven wheels  114  for a total of eight driven wheels  114 . The eight driven wheels  114  are arranged in pairs, and each pair is arranged on a tandem drive beam  116 . Four such tandem drive beams  116  are included with the forwarder  102  to provide traction and stability when traversing rough and/or uneven terrain. Although a forwarder  102  including eight driven wheels  114  is illustrated, the machine  100  could alternately include only four or six wheels. As with the illustrated embodiment, all or a portion of the wheels  114  may be driven. Alternate ground engaging members  112  may include, for example, track mechanisms. 
     The payload portion  108  of the illustrated embodiment includes four bunks  118  that are arranged along the payload frame portion  108  and extend from a segment thereof that is adjacent to the base  120  along the length of the payload frame portion  108 . Each of the four bunks  118  has a flattened Y-shape having base  122  extending horizontally away from a longitudinal centerline, C, of the forwarder  102  and a pair of posts  124  extending upwardly. When logs or other elongate cargo is loaded on the forwarder  102 , the four bunks  118  are disposed to retain and align the cargo onto and over the payload frame portion  108  within the space between each pair of posts  124 . A headboard  126  is connected to the payload frame portion  108  and extends in a generally vertical direction away from the articulated frame  104 . The headboard  126  provides a bumper or stop that protects the base  120  and the crane  128  from impacts with logs being loaded on the forwarder  102  while also providing a surface that the operator can use to “bump” and align the logs being loaded. 
     In the illustrated embodiment, the engine frame portion  106  supports a prime mover (not visible) beneath an engine cover  130  and a cab or operator station  132 . The forwarder  102  may include any appropriate prime mover for movement of the forwarder  102  and operation of the various systems. For example, the prime mover may be an engine. A drive system using electrical or mechanical power may be used to operate the driven wheels  114 . Alternately, the drive system may include hydrostatic motors associated with the eight driven wheels  114 . A hydraulic system may further be provided to operate hydrostatic actuators are also used to actuate the boom or crane  128 . The crane  128  is connected to the frame  104  at one end and is provided with a grapple assembly  133  at the opposite end. 
     Referring to  FIG. 3 , the operator station  132  includes a seat  134 , and a plurality of machine controls for operation of the various operations of the forwarder  102 . The machine controls may include, for example, a steering wheel  136 , and/or control mechanisms  138  disposed on the arms of the seat  134  itself, such as one or more joysticks  140 , buttons  141 , or switches. To allow the operator to view the environment forward, to the sides, and to the rear, the operator station  132  includes a plurality of windshields  142 ,  144 ,  146 . While only three windshields are visible in  FIGS. 1 and 2 , windshields  142 ,  144 ,  146 ,  148 ,  150 ,  152  may be provided about the operator station  132 , as shown in the fragmentary schematic plan view of the operator station  132  in  FIG. 3 . Further, two or more of the windshields  142 ,  144 ,  146 ,  148 ,  150 ,  152 , here, four such windshields are provided with at least one respective windshield wiper  154 ,  156 ,  158 ,  160 . 
     To facilitate driving the machine  100  as well as the operator&#39;s use of the crane  128 , the seat  134  is pivotally mounted within the operator station  132  such that it may be pivoted selectively and at least partially between forward and rearward facing positions. The mounting may be accomplished by any appropriate arrangement. For example, the seat assembly  170 , as may be seen in  FIG. 4 , in addition to the seat  134  itself, may include a base  172  having a stationary portion  174  that is secured to the floor of the operator station  132 , and a rotating portion  176  to which the seat  134  is secured (see  FIGS. 5 and 6 ). In this embodiment, the stationary portion  174  is a generally circular structure that is mounted to the floor of the operator station  132  by a plurality of threaded projections  178  and associated nuts  180 . Washers  182  or the like may be provided to inhibit the nuts  180  from unthreading. 
     The rotating portion  176  here includes a generally planar structure or plate  184  that is coupled to the stationary portion  174  by a plurality of mounting flanges or brackets  186 . The brackets  186  are removably coupled to the plate  184  by rivets, screws  188 , or the like. Ball bearings or the like (not visible) may be disposed between the stationary portion  174  and the plate  184  to provide smooth motion of the seat  134  as it pivots. 
     The seat  134  itself is mounted to the plate  184  by any appropriate means. In this embodiment, the rotating portion  176  includes a pair of longitudinally extending mounting bars  190  to which the seat  134  is mounted. While the seat assembly  170  has been described with regard to the illustrated arrangement, it will be appreciated that alternate arrangements are likewise appropriate with regard to the appearance, seat structure, and mounting structure, among other things. 
     In order to minimize unnecessary usage of the wipers  154 ,  156 ,  158 ,  160 , selective operation of the wipers  154 ,  156 ,  158 ,  160  is provided, based upon the needs or desires of the operator, on the safety of the operator and on the safe usage of the machine. Accordingly, the operator station  132  includes controls that enable operation of a limited number of the wipers  154 ,  156 ,  158 ,  160 , depending upon the direction in which the seat  134  is facing. For example, if the seat  134  is facing generally forward, that is, toward the steering wheel  136  and front windshield  148 , the front wiper  158  is operative, and the rear, right, and left side wipers  154 ,  156 ,  160  are inoperative. Conversely, if the seat  134  is facing generally rearward or sideward, the rear, right and left side wipers  154 ,  156 ,  160  are operative, while the front wiper  158  is not. Further, the wiper arrangement may be provided with additional functionality beyond a conventional on/off arrangement such that actuation may provide a limited number of sweeps, such as a single sweep of the wipers  154 ,  156 ,  158 ,  160 . In this way, the operator&#39;s actuation of the appropriately enabled wipers  154 ,  156 ,  158 ,  160  would yield, for example, a single sweep of the wipers across only the windshields  142 ,  144 ,  148 ,  152  in use. 
     This limited operation of the wipers  154 ,  156 ,  158 ,  160  may be provided by any appropriate mechanism. Referring to  FIGS. 5 and 6 , in the illustrated embodiment, the seat assembly  170  is provided with a plurality of control devices, such as proximity sensors  200 ,  202 , here, two such sensors  200 ,  202 , which are coupled to the rotating portion  176 . The plate  184  of the rotating portion  176  is provided with a central opening  204  through which a stationary flange  206  protrudes. Here, the stationary flange  206  is coupled to the stationary portion  174 , although is could alternatively be coupled, such as, to the floor of the operator station  132 . The stationary flange  206  may likewise include a central opening  208  to allow the passage of cables or the like, if desired. Here, the sensors  200 ,  202  are electrically connected to the wiper control mechanisms  138  disposed in the seat assembly  170  by an electrical bus  210  that extends through the openings in both the stationary portion  174  and the rotating portion  176 , and other electrical connections. As the seat  134  and the plate  184  to which it is coupled rotate, the flange  206  actuates one or the other of the proximity sensors  200 ,  202 , depending upon the position of the rotating portion  176 . The proximity sensors  200 ,  202  are disposed and electrically connected and the flange  206  is disposed such that one of the sensors  200  allows operation of the front wiper  158  upon proximity actuation by the flange  206 , while the other sensor  202  allows operation of the rear, right, and left side wipers  154 ,  156 ,  160  upon proximity actuation by the flange  206 . In this way, the control mechanisms  138  located in the seat assembly  170  are operative to actuate only one or the other of the front wiper  158  or the rear, right, and left wipers  154 ,  156 ,  160 , depending upon the swiveled location of the seat assembly  170 . 
     It will be appreciated that the arcuate nature of the flange  206  enables operation of the wipers  154 ,  156 ,  158 ,  160  associated with the actuated proximity sensors  200 ,  202  when the seat is disposed at a range of angles, rather than only precisely forward facing or rearward facing. This arrangement allows the operator to adjust the seat  134  to a desired location and still actuate the appropriate wipers while providing the operator some flexibility in the exact positioning of the seat  134 . For example, an operator may prefer to operate the crane  128  with the seat  134  facing slightly to one side or the other, based upon the location of logs to be moved in to the payload portion  108  of the forwarder  102 . 
     Further, while two sensors  200 ,  202  are illustrated, a fewer or greater number of sensors or the like may be provided. For example, a first sensor may be provided to activate and a second sensor to deactivate the front wiper  158 ; a third sensor may be provide to activate and a fourth to deactivate the rear, right and left side wipers  154 ,  156 ,  160 . 
     A schematic diagram of  FIG. 7  illustrates a representative control arrangement  212  for controlling the operation of the wipers  154 ,  156 ,  158 ,  160 . A control device  214  creates a control signal as a result of the swiveling of the is created as a result of the rotating portion  176  relative to the stationary portion  174 . In the embodiment of  FIGS. 5-6 , the control device  214  includes the sensors  200 ,  202  and the flange  206 . Alternate arrangements are equally appropriate. By way of example only, one or more mechanical switches or the like may be provided such that the swiveling of the rotating portion  176  causes activation and/or deactivation of the switches. 
     Returning to  FIG. 7 , the control signal from the control device  214  is provided to a control unit  216 , which may be in the form of a central processing unit, a microprocessor, or another controller. The control unit  216  then provides signals to the relays  218 , which in turn activate the appropriate wiper(s)  154 ,  156 ,  158 ,  160  to allow further actuation by the operator by way of appropriate control mechanisms  138 . It will be appreciated that alternate control arrangements may be provided, and that the illustrated control arrangement  212  is provided merely by way of example. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure is applicable to machines  100  having a seat  134  that swivels between two or more stations and at least one wiper  154 ,  158  at each of the stations. In an embodiment, the disclosed arrangement may be utilized on machines  100  having greater than two windshields and associated wipers. 
     In an embodiment, the arrangement may be utilized in conjunction with traditional wiper controls. For example, the arrangement may include controls for the enabled wipers  154 ,  158  that allow the wipers  154 ,  158  to be switched on continuously, intermittently, and/or as a single or other controlled number of sweeps. Controls may be provided whereby the operator may actuate each of the wipers individually, or as a group. In an embodiment, a control arrangement  212  may be provided wherein actuation of a control mechanism  138  results in a preselected number of swipes of the wiper(s), as, for example, a single swipe. 
     Activation of a limited number of the wipers  154 ,  156 ,  158 ,  160  based upon seat  134  location may result in reduced wear on the wiper blade and the associated windshields  142 ,  144 ,  148 ,  152 . Placement of the wiper control mechanisms  138  along the seat  134  itself may result in reduced distraction to an operator during use. 
     Some embodiments may be economically manufactured, and/or may be readily incorporated into such machines  100 . 
     It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.