Abstract:
A mechanism is provided for engaging and disengaging the reverse operation of a feederhouse of a harvesting apparatus. The mechanism solves the problem of accurate engagement between the shift collar or driving element and the reverse gear, teeth or splines and the forward gear, teeth or splines of the feederhouse transmission. The mechanism comprises an actuator, electrically controlled, which loads or compresses a spring, wherein the spring exerts a shifting force on a shift shaft or shift fork of the gearbox which automatically moves the shift collar or driving element of the transmission into either a forward or reverse drive position when the gear, teeth of splines of the shift collar is aligned or meshed with the gear, teeth or splines of either the reverse or forward drive of the feederhouse transmission.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The invention is directed to a reverser for a feederhouse of a harvesting apparatus. The reverser is particularly well adapted for use in combines.  
         BACKGROUND OF THE INVENTION  
         [0002]    Agricultural combines are typically provided with an outwardly extending feederhouse for directing harvested crop from a harvesting platform into the combine. In difficult crop conditions, it is possible to plug the feederhouse by the harvested grain. As such, some method is needed to free the plug.  
           [0003]    U.S. Pat. No. 4,879,868 discloses a reverser assembly that can be used to reverse the feederhouse used for transmitting small grains into the combine. The main driven sheave is provided with an externally toothed cooperating assembly that is selectively engaged by an internally splined drive element that can be moved along the drive shaft. The drive shaft is provided with external splines that cooperate with the internal splines of the drive element so that when the drive element is operably coupled to the toothed cooperating assembly of the main driven sheave, the main driven sheave drives the drive shaft. The drive element is also provided with a gear assembly that can be operably coupled to a toothed cooperating assembly located on the second driven sheave. By sliding the driven element away from the main driven sheave, the drive element disengages the toothed cooperating assembly of the main driven sheave and the second toothed element engages the toothed cooperating assembly of the second driven sheave. Thereby, the main driven sheave becomes operatively disengaged from the drive shaft and the second driven sheave now drives the drive shaft. By coupling the second toothed assembly to the toothed cooperating assembly on the second driven sheave, the output is effectively reversed, reversing the rotation of the feederhouse drive shaft.  
           [0004]    The positioning of the drive element is controlled by a push/pull cable having a handle located in the operator&#39;s cab of the combine. The push/pull cable is operatively coupled to a bell crank that is coupled to the drive element by a link.  
           [0005]    Another feederhouse drive and reverser assembly is described in U.S. Pat. No. 4,138,837. In this patent, a planetary gear set arrangement is described that facilitates the provision of a reverse drive, including a single ring gear assembly and a control linkage. The ring gear is maintained in his radial position by its engagement of the planetary pinions of the gear set. A shifting collar, splined to an output shaft, transmit output from the planetary gear set to that shaft, selectively engaging either a sun gear for the reduced speed forward drive or, internally, a hub plate attached to the ring gear for the reverse drive. The control linkage includes a push-pull control cable connected to a manual control handle located in the operator&#39;s station.  
           [0006]    In the John Deere 10 Series Combine, the reverser is activated by pressing a pedal in the cab that is connected to a push/pull cable routed to the shift collar or drive element in the gearbox. However, when the selected gear and shift collar are misaligned, it is necessary to maintain pressure on the pedal and “jog” the front end drive to the on and off position until the gear and shift collar are aligned. Once the components become aligned, the shift collar will slide over allowing the gearbox to be switched to reverse drive.  
           [0007]    In the aforementioned assemblies, successful engagement of the reverser depends upon proper drive element or collar and gear alignment. Frequently, the operator must attempt several times to engage the reverser using either the manual lever or pedal, decreasing operator efficiency.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention provides a mechanism for engaging and disengaging the reverse operation of a feederhouse of a harvesting apparatus. The mechanism solves the problem of accurate engagement between the shift collar or drive element and the reverse gear, teeth or splines and the forward gear, teeth or splines of the feederhouse transmission. The mechanism comprises an actuator, electrically controlled, which loads or compresses a spring, wherein the spring exerts a shifting force on a shift shaft or shift fork of the gearbox which moves the shift collar or drive element of the transmission into either a forward or reverse gear engagement.  
           [0009]    According to the preferred embodiment, the mechanism includes a plunger. The actuator and plunger are mounted in series with the shift shaft or shift fork of the gearbox, on the bottom side of the feederhouse. The actuator drives the plunger and the plunger compresses the spring. The spring stores the energy provided by the actuator, allowing the shift inside the gearbox to occur when the gears, teeth or splines are correctly aligned. If the gears are meshed correctly, the shift occurs instantaneously. However, if misalignment is present, the spring retains force on the shift shaft or shift fork in the direction of the proposed shift. When the operator selects a shift from forward to reverse, or vice versa, the shift will take place automatically once the gears, teeth or splines are aligned properly.  
           [0010]    The required motion to engage and disengage the feederhouse reverser is supplied by the actuator. Preferably, the actuator is an electrically driven device. A switch in the operator&#39;s station or cab allows the user to remotely actuate the actuator to complete the selected motion. Due to the energy stored in the spring, the operator can make a reverser shift selection once, and allow the system to engage when the shift collar is aligned with the selected one of either the forward or reverse gears, teeth or splines.  
           [0011]    According to a further development of the shift control of the invention, the engine delivers rotary power to a controllable clutch. The clutch, when engaged, delivers rotary power to the transmission of the feederhouse. A controller is signal-connected to the controllable clutch, via appropriate signal conditioning, to control the engagement/disengagement of the clutch. The operator-controlled switch is signal-connected to the controller.  
           [0012]    When the switch is thrown to engage, or alternately to disengage, the reverser, the controller disengages the clutch. A speed sensor monitors the speed of the transmission gears, such as via an output shaft engaged to the driven side of the clutch. When the shaft has stopped, the controller causes the actuation of the actuator. Additionally, the controller can then send a signal to the clutch to pulsate the clutch to cause a slow movement of the gears within the transmission until the reverse gears, teeth or splines, or alternately the forward gears, teeth or splines , are aligned with the shift collar gears, teeth or splines. Once aligned the shift occurs. The transmission can be configured to send a feedback signal to the controller, the signal confirming the successful occurrence of the shift. Alternatively, the controller can cause the clutch to pulsate only for a preset time interval, requiring a second attempt to shift if the shift has not successfully occurred. The controller then engages the clutch and full rotary power is once again communicated to the feederhouse transmission.  
           [0013]    According to the present invention, a shift into reverse operation, or back to forward operation, can be accomplished by a simple action of throwing a switch. The operator need not manually jog the gears of the feederhouse transmission in order to mesh the reverse or forward gear assemblies. The shift will be automatically accomplished. The automatic control of the reverser operation will result in less damage due to operator error caused by attempting to shift while the transmission gears have not sufficiently decreased in speed. The switch is easier and more convenient for the operator to actuate compared to foot operated or hand operated push-pull cables. Furthermore the elimination of the push-pull cable eliminates a dust and noise entry point into the cab.  
           [0014]    Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a schematic side elevational view of a combine embodying the invention.  
         [0016]    [0016]FIG. 2 is an enlarged semi-schematic partial side elevation of the combine of FIG. 1.  
         [0017]    [0017]FIG. 3 is a sectional view on line  3 - 3  of FIG. 2 of the planetary transmission assembly showing the shift collar engaging the planetary output gear for forward drive.  
         [0018]    [0018]FIG. 4 is a partial view, similar to FIG. 3 showing the shift collar engaging the ring gear clutch plate for reverse drive.  
         [0019]    [0019]FIG. 5 is an enlarged partial sectional fragmentary view of the shift mechanism of the invention.  
         [0020]    [0020]FIG. 6 is an electrical schematic of the control system for the shift mechanism of FIG. 5.  
         [0021]    [0021]FIG. 7 is a schematic of a further development of the control system for the shift mechanism of FIG. 5. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawings, and will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.  
         [0023]    [0023]FIG. 1 illustrates a self-propelled combine having a main separator body  10 , mounted on a pair of forward drive wheels  12  and steerable rear wheels  14 . An elevated operator&#39;s station  16  is mounted at the front of the separator body  10 . A forward mounted header indicated generally by the numeral  18  is pivoted on a horizontal transverse pivot (not shown) at the front of the separator body  10  for vertical adjustment by conventional means. The header includes a feeding unit  20  and a gathering unit  22 . A transversely oriented internal combustion engine  24  indicated in schematic outline only in FIG. 1, is mounted toward the front of the separator body  10  and has an output power shaft  26  extending from the left-hand side of the separator body. A belt-type drive system indicated in its entirety by the numeral  28  is disposed on the left side of the combine and transmits power from the engine power shaft  26  to the header  18 .  
         [0024]    The belt drive system  28  includes a primary countershaft  30  mounted on the combine body  10  and connected to the engine power shaft  26  by a primary countershaft belt drive  32 . A movable countershaft assembly  34  is mounted on the left-hand side of the feeding unit  20  and is connected to the primary countershaft  30  by a header transfer drive indicated generally by the numeral  36 . A header drive shaft  38  is mounted transversely beneath the forward end of the feeding unit  20  as shown most clearly in FIG. 2. The header drive shaft  38  is connected to the movable countershaft  30  by a header drive indicated generally by the numeral  40  in FIGS. 1 and 2. Final drives to the feeding unit  20  and the gathering unit  22  are taken from the header drive shaft  38  by conventional means such as the platform drive  42  indicated schematically in FIG. 1.  
         [0025]    The feeding unit  20  shown in schematic outline in FIG. 2 includes a pair of opposite upright sidewalls  44 , a top wall  46  and a bottom wall  48 .  
         [0026]    A V-belt  124  of the header drive  40  transmits power from the movable countershaft assembly  34  to the header drive shaft  38  via a transmission assembly indicated in its entirety by the numeral  126 , coaxial with and drivingly engaging the header shaft  38 .  
         [0027]    The transmission assembly  126 , best shown in FIG. 3, is mounted on the left-hand sidewall  44  of the feeding unit toward its forward end by a bracket assembly  128  (shown only in FIG. 2) and disposed so that the header drive shaft  38  lies transversely immediately beneath the bottom wall  48  of the feeding unit. The transmission assembly  126  combines, in an integrated unit, a planetary transmission indicated generally by the numeral  130  and a sheave assembly indicated generally by the numeral  132 .  
         [0028]    The sheave assembly  132 , driven by the V-belt  124 , is of the variable effective diameter torque-sensing or torque responsive type, and includes an axially fixed sheave element  134  and an axially adjustable sheave element  136 . A compression spring  138  carried between a spring retainer  140  and the movable sheave element  136  biases that element axially towards the fixed sheave element  134  in the direction of increasing effective diameter. The torque-sensing or torque responsiveness of the sheave assembly  132  depends upon control of relative rotation between the two sheave elements  134  and  136 , and is effected by a cam assembly  142  annularly contained between them.  
         [0029]    The cam assembly  142  is so disposed between the sheave elements  134  and  136  that any tendency for relative rotation between the two sheave halves results in a cam action biasing the axially adjustable sheave element  136  toward sheave element  134 . The sheave assembly  132  is rotatably carried on the header drive shaft  38  by a hub-like extension  144  of an input sun gear  146  journaled on the shaft  38  by a pair of the bearings  148 . The sheave assembly  132  is drivably keyed and secured to the input gear hub  144  by a key  150  and setscrews  152  respectively.  
         [0030]    The planetary transmission  130  includes a generally annular bell-shaped gear housing  154  that includes the actual attaching points (not shown) of the transmission assembly  126  to the bracket assembly  128 . The inner end of the gear housing  154  includes a bearing housing  156  and the outer end has an annular flange  158 .  
         [0031]    A boss  160  having a bore  162  parallel to the header drive shaft and communicating with the interior of the gear housing  154  extends axially from the rearward side of the gear housing adjacent the bearing housing  156 . A pinion carrier  164  closes the bell mouth of the gear housing  154  and includes a cover portion  166  secured to the flange  158  of the gear housing  154  by a plurality of fasteners  168 . The pinion carrier  164  includes a pinion carrier structure  170  extending axially from the cover portion  166 .  
         [0032]    The gear housing  154  and the pinion carrier  164  together form a gear housing assembly through which the header drive shaft  38  rotatably extends, carried by bearings  172  and  174 , housed in the bearing housing  156  of the gear housing and in a central bore of the pinion carrier  164 , respectively. Annularly interposed between the bearings and the shaft are a shaft hub  176  and the input gear hub  144  respectively. A woodruff key  178  drivingly connects the shaft hub  176  to the shaft  38 . An enlarged diameter portion of the shaft hub  176  extends within the gear housing  154  and includes external splines  180  and a snap ring groove  182  intersecting the splines.  
         [0033]    The pinion carrier structure  170  includes a plurality of bores  184  carrying a plurality of pins  188  on which are journaled, by a plurality of bearings  190 , pinion gears  192 . Each pinion gear  192  includes, as integral parts, a first planetary pinion  194  immediately adjacent the pinion carrier cover and drivably engaging the input sun gear  146 , and a second planetary pinion  196  immediately adjacent the first. The second planetary pinions  196  drivingly engage and carry a ring gear assembly  198  which includes a ring gear  200  and a concentrically dished clutch plate  202  secured to the ring gear by a plurality of fasteners  204 . The ring gear assembly is free to float in the gear housing  154 , its movement being limited radially only by the engagement of the ring gear  200  with the second planetary pinions  196 , and axially by the confinement of the clutch plate  202  between adjacent faces  206  and  208  of the gear housing  154  and pinion carrier structure  170 , respectively. An output sun gear  210  is interposed, concentrically with the header drive shaft  38 , between the shaft hub  176  and the input sun gear  146 . The output sun gear  210  includes a spur gear portion  212  drivably engaging the second planetary pinions  196  and, immediately adjacent the shaft hub  176 , a hub-like extension  214  bearing external splines  216  matching those ( 180 ) of the shaft hub  176 . The output sun gear  210  has an internal bore  218  exceeding the diameter of adjacent portions of the header drive shaft  38  and is maintained in position radially only by its engagement with the teeth of the second planetary pinions  196  and axially by its close confinement between the shaft of  176  and the input sun gear  146 .  
         [0034]    An internally splined shifting collar  220  is slidably carried on the matching splines of the shaft hub  176  and is axially disposed so that the internal splines  221  (shown in FIG. 3) selectively also engage (as shown in FIG. 3) or disengage the external splines  216  of the output sun gear  210  so that the shaft hub  176  is selectively coupled to, or uncoupled from, the output sun gear  210 . An increased diameter outer portion of the shifting collar  220  bears an external splined section having external splines  222  matching internal splines  202   a  of the clutch plate  202 . The inner end of the shifting collar has an external annular groove  224 . The shifting collar  220  is also disposed axially so that the internal splines  202   a  of the clutch plate  202  selectively drivably engage (as shown in FIG. 4) or disengage the matching external splines  222  of the shifting collar so that the shaft hub  176  is selectively coupled to, or uncoupled from, the ring gear assembly  198 .  
         [0035]    A shifting assembly  226  has a shift shaft or shift fork  228  slidably disposed in the bore  162  of the boss  160  of the gear housing  154 . The shaft  228  extends into the gear housing  154  and carries a shifter plate  230  that engages the external groove  224  of the shifting collar  220 .  
         [0036]    As previously stated, the header drive shaft  38  extends transversely beneath the feeding unit  20 . Its right-hand end (not shown) extends beyond the right-hand sidewall  44  of the feeding unit and is journaled adjacent its end in a bearing supported by the feeding unit  20 . Final drives to the feeding and gathering units are taken from the shaft  38  by conventional means including chain or splined couplers, a typical chain coupler half  238  being shown in FIG. 3, retained on the header drive shaft  38  by cap screw  240 . A header drive arrangement, using splined couplers in the header drive shaft is disclosed in U.S. Pat. No. Re 26,512.  
         [0037]    The input to the planetary transmission  130  is through the input sun gear  146  which is keyed to the driven sheave assembly  132 , the gear and sheave assembly being journaled as a unit on header drive shaft  38 . For normal (forward) harvesting operation, the operator, by means of a direction switch  236  mounted in the operator&#39;s station, shown in FIG. 2 and described below, moves the shifting collar  220  to the position shown in FIG. 3, which drivingly connects the output sun gear  210  with the header drive shaft  38  so that the shaft is driven through the planetary pinion  192  and output gear  210  at a speed considerably slower than that of the sheave assembly  132 .  
         [0038]    To drive the gathering and feeding unit in the reverse direction, for example to clear a blockage, the operator moves the shifting collar  220  to the position shown in FIG. 4 where and the ring gear assembly  198  is drivingly connected to the header drive shaft  38 . Drive is now transmitted from the input sun gear  146  through the planetary pinion  192  and the ring gear  198  so that the shaft  38  is driven in a reverse direction.  
         [0039]    [0039]FIG. 5 illustrates the shifting mechanism  226  in accordance with the invention. The shifting mechanism  226  includes an electrical actuator  242 , such as a linear actuator, having an actuator rod  244  connected via a chain link  246  to a plunger  250 . The actuator can be a Warner ELECTRAK ONE with a seventy-five pound force to a two-inch stroke, and a maximum current draw of 6A at 12VDC.  
         [0040]    A spring system  256  is connected to the actuator rod  244 . The spring system  256  includes a housing or tube  258  holding a first compression spring  260  and a second compression spring  264 . The plunger  250  includes a rod  270  penetrating into the tube  258 , the rod  270  connected to a head  276 , the head  276  enclosed in the tube  258 . The tube has a reduced diameter opening  280  on a base end  281  thereof to retain the first spring  260 , and a threaded closure  284  fit on an opposite end of the cylinder to retain the second spring  264 . The threaded closure includes a threaded central hole  286  that allows the threaded closure to be screwed onto a threaded end of the shift shaft  228  of the transmission  130 . The spring system is contained inside the tube to prevent distortion of the springs, and to maintain the direction of force.  
         [0041]    In operation, the operator engages the feederhouse reverser by changing the state of the switch  236  located in the operator&#39;s station. When the switch is closed, and current flows to the actuator, the actuator  242  will retract the actuator rod  244  a pre-selected distance to the left in FIG. 5, such as two inches, to pull the plunger  250 . The plunger  250  will apply a compression force on the first spring  260 , compressing the first spring. The first spring  260  in turn applies pressure on the base end  281  of the tube  258 . This movement causes the spring assembly  256  and shift shaft  228  to be pulled toward the actuator  242 , generating the shift force. The shift force remains via the compressed spring  260  until the internal splines  202   a  of the clutch plate align with the splined section  222  of the shift collar  220 . When alignment occurs, the feederhouse reverser is engaged by the shift force.  
         [0042]    To disengage the feederhouse reverser, a similar sequence occurs. The actuator  242  will extend, moving the plunger  250  a distance to the right in FIG. 5, such as two inches to compress the second spring  264 . The compressed spring  264  causes a force to be applied on the shift shaft  228 . If the shifting collar internal splines  221  are not precisely aligned with the external splines  216  of the output sun gear  210 , the spring  264  will remain compressed to store energy. As the gearbox rotates, the splines  221 ,  216  will eventually align and be meshed by force from the spring  264  via the shift shaft  228 .  
         [0043]    Each spring is in compression only during one direction of movement.  
         [0044]    A bracket  290  can be used to secure the shift mechanism  226  to the bottom wall  48  (FIG. 2) of the feederhouse, to restrict unwanted movement during extension and retraction. All force supplied by the actuator  242  is applied to the plunger  250 .  
         [0045]    [0045]FIG. 6 illustrates the electrical system  300  for the shift mechanism  226 . The switch  236  can be a single-pull, single-throw (SPST) switch located in the instrument panel of the operator&#39;s station. An electrical relay  304 , such as a dual-pull, dual-throw (DPDT) relay, is used to reduce the current draw through the switch  236 , and to reduce the length and gauge of the wiring. Actuation is achieved by reversing the polarity of the supply voltage by throwing the switch  236 . Conductors A and B are thus alternatively at drive voltage, such as 12 volts, or ground depending on the selected direction of shift of the actuator  242 . The conductors are routed to the actuator  242  via a cable  309 .  
         [0046]    To maintain a high reliability and high product life, the switch can be integrated into a control system so that the shift cannot occur while the combine is at full throttle or while the separator is engaged. A combine controller C can be signal-connected to a relay or switch  310 . The switch  310  is connected in series with the switch  236 . The switch  236  for the reverser can thus be electrically dependent on the throttle position or on the header shut-off switch. As a result, the shift of the feederhouse into reverse gear cannot occur unless damage-preventive steps are taken.  
         [0047]    [0047]FIG. 7 illustrates a further development of the control of the reverser shift mechanism of the invention. According to this control scheme, the engine delivers rotary power to a hydraulically operated clutch  350  which is spring-engaged and hydraulically disengaged. The clutch  350 , when engaged, delivers rotary power to the output shaft  26  which delivers rotary power to the belt system  38 . A hydraulic proportional control valve  354  delivers a controlled-pressure hydraulic fluid to the clutch  350 . The controller C is signal-connected to the control valve  354 , via appropriate signal conditioning, to control the engagement/disengagement of the clutch  354 . The switch electrical system  300  is signal-connected to the controller C.  
         [0048]    When the switch  236  is thrown to engage the reverser, the controller disengages the clutch, via control of the control valve  354 . A speed sensor  360 , such as a Hall effect sensor, monitors the speed of the output shaft. When the shaft  26 , and thus the clutch plate  202 , has sufficiently slowed or stopped for engagement of the internal splines  202   a  of the clutch plate  202  to the splined section  222  of shift collar  220 , the electrical system  300  energizes the actuator  242 . Additionally, the controller C can then send a signal to the clutch control valve  354  to pulsate the clutch  350  to cause a slow movement of the gears within the transmission until the internal splines  202   a  of the clutch plate  202  align with the splined section  222  of the shift collar  220 . Once aligned the shift occurs. The transmission  126  can be configured to send a feedback signal to the controller C, the signal confirming the successful occurrence of the shift. Such a feedback signal can be, for example, based on the movement of the shift shaft  228 . The controller C then engages the clutch  350 , via the control valve  354 , and full rotary power is once again communicated to the feederhouse transmission. Alternatively, the controller can cause the clutch to pulsate only for a preset time interval, requiring a second attempt to shift if the shift has not successfully occurred.  
         [0049]    To disengage the feederhouse reverser, a similar sequence occurs. When the switch  236  is thrown to disengage the reverser, to revert to normal, forward operation, the controller disengages the clutch, via control of the control valve  354 . A speed sensor  360 , such as a Hall effect sensor, monitors the speed of the output shaft. When the shaft  26 , and thus the output sun gear  210 , has sufficiently slowed or stopped for engagement of the output sun gear  210  with the shift collar  220 , the electrical system  300  energizes the actuator  242 . Additionally, the controller C can then send a signal to the clutch control valve  354  to pulsate the clutch  350  to cause a slow movement of the gears within the transmission until the shifting collar internal splines  221  are precisely aligned with the external splines  216  of the output sun gear  210 . As the gearbox rotates, the splines  221 ,  216  will eventually align and be meshed by force from the spring  264  via the shift shaft  228 , i.e., the shift occurs. The transmission  126  can then send a feedback signal to the controller C, the signal confirming the successful occurrence of the shift. Alternatively, the controller can cause the clutch to pulsate only for a preset time interval, requiring a second attempt to shift if the shift has not successfully occurred. The controller C then engages the clutch  350 , via the control valve  354 , and full rotary power is once again communicated to the feederhouse transmission.  
         [0050]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.