Abstract: A method is carried-out by a controller architecture coupled to a beam assembly actuator, which is included in an articulating tongue arrangement connecting an agricultural implement to a tow vehicle. In an embodiment, the method includes: (i) monitoring, via the controller architecture, an effective tow length of an articulating beam assembly further included in the articulating tongue arrangement, the effective tow length measured along a straight line extending from a leading pivot joint of the articulating tongue arrangement to a trailing pivot joint of the articulating tongue arrangement; (ii) determining, at the controller architecture, an effective tow length target of the articulating tongue arrangement based upon operator input, sensor input, or a combination thereof; and (iii) transmitting commands from the controller architecture to the beam assembly actuator to maintain the effective tow length of the articulating beam assembly in conformance with the effective tow length target.

Abstract: A baler includes a near-infrared testing system configured to receive near-infrared radiation reflected by plant material in a bale and to analyze the near-infrared radiation and generate evaluation data reflecting one or more properties of the plant material. The near-infrared testing system is calibrated using a calibration sample at a calibration temperature. A temperature sensor measures a sample temperature of a crop sample of the plant material and a temperature alteration mechanism adjusts the sample temperature of the crop sample so that the sample temperature matches the calibration temperature of the calibration sample before the near-infrared testing system receives the near-infrared radiation reflected by the plant material. A computer receives and combine the evaluation data of the plant material to produce overall evaluation data reflecting one or more overall properties for the at least one bale of the plurality of bales, and assign the overall evaluation data to the bale.

Abstract: An apparatus and method for baling plant materials such as grasses, leaves and pine straw a hydraulic power unit, a conveyor operatively coupled to the hydraulic power unit, a hopper for depositing the material on a proximal end of the conveyor and a baler operatively coupled to the hydraulic power unit and arranged for receiving a material from the conveyor. The power unit, conveyor and baler are supported on a trailer. An electronic control system is operatively coupled to the hydraulic power unit, the conveyor and the baler for automatically suspending operation of the conveyor when the baler contains a sufficient amount of material for initiating bundling of the material and automatically resuming operation of the conveyor following dispensing of a bundle of the material from the baler.

Abstract: Systems and methods for estimating remaining life in an agricultural baler comprise a reciprocating plunger for compressing gathered agricultural material into bales. A first sensor generates signals corresponding to force applied to the reciprocating plunger and any baling components configured to at least partially carry forces applied to the plunger. Based on input signals from at least the first sensor, forces associated with a load are recorded and a life state is estimated for the reciprocating plunger and/or at least one associated baler component. An output signal is then generated corresponding to the one or more estimated life states. In an embodiment, an input signal from a second sensor indicates completion of a bale, wherein an amount of life consumed from the plunger and/or baling components is determined in association with the bale, based at least in part on operating conditions of the baled material.

Abstract: A round baler includes a housing, and a gate rotatably attached to the housing. A bale holder is attached to and moveable with the gate. The bale holder includes a retractable member that is moveable between an engaged position operable to grasp a bale and move the bale with the gate, and a disengaged position operable to release the bale. The retractable member is positioned to grasp an end face of the bale at a contact location. The contact location is disposed rearward of a vertical reference plane passing through a centerline of the bale when the bale is within an interior region of the round baler and the gate is in the closed position. The contact location may be disposed below a horizontal plane passing through the centerline of the bale when the bale is within the interior region and the gate is in the closed position.

Abstract: A high capacity square baler including a pickup mechanism configured to pick up a single windrow of crop material off the ground. The baler additionally includes one or more stuffer chutes each configured to receive at least a portion of the crop material picked up by the pickup mechanism. The baler additionally includes one or more stuffer assemblies each configured to push crop generally upward through one of the stuffer chutes. The baler further includes a plurality of separate bale-forming chambers each configured to receive crop material from one or more of the stuffer chutes and to form a bale of crop material therein.

Abstract: Self-propelled vehicles for forming bales of crop or forage material are disclosed. The self-propelled baling vehicles include independently driven real wheels and front caster wheels that allow the baling vehicle to turn with a counter-steer profile. In some embodiments, the center of mass of the formed bale is toward the rear of the vehicle to improve the weight distribution of the vehicle.

Abstract: A harvesting system includes at least one modular unit coupled to a harvester includes a drying unit to dry a harvested material introduced into the harvester including at least one rotating drum, a number of appendages extending from the at least one rotating drum, at least one sensor to determine at least one environmental state within the drying unit, and at least one environmental state adjustment device to adjust at least one environmental attribute within the drying unit. The modular unit also includes a collection unit to collect the harvested material into a unit, a first conveyor mechanism to convey the harvested material from the drying unit to the collection unit, and a control system to control at least the harvester, the drying unit, the collection unit, the first conveyor mechanism, the sensor, and the environmental state adjustment device based on a signal received from the at least one sensor.

Abstract: A supply apparatus for supplying wrapping material to a wrapper inlet of a baling chamber, in which a bale is to be wrapped. A reservoir supplies the wrapping material to an upper driven roller forming a lower part of the wrapper inlet. The wrapping material is guided to the wrapper inlet from above the wrapper inlet. A displaceable supply unit is located between the reservoir and the upper driven roller, the supply unit being moveable between a baling position and a wrapping position about a pivot axis located above the wrapper inlet. A free end of the wrapping material outside of the baling chamber is protected by the displaceable supply unit from air turbulence during operation of the baling apparatus.

Abstract: An agricultural baler including a baling chamber and a pre-compression chamber, the baling chamber including at least one movable wall. The agricultural baler further includes multiple sensors and a controller adapted for controlling operation of the agricultural baler based on inputs of the multiple sensors, wherein a first subset of the multiple sensors is related to a first feature and a second subset of the multiple sensors is related to a second feature. The controller is configured to control the operation of the agricultural baler in a first time period until the first feature is within a first predetermined range, and to control the operation of the agricultural baler in a subsequent time period, until the second feature is within a second predetermined range.

Abstract: A crop cutting device including knives pivotally mounted below a crop guiding surface. Each knife is pivotable between a retracted position in which it is located below the guiding surface and an extended position. At least a cutting edge of the knife projects above the surface. A selector mechanism selectively holds spring loaded parts of operating members to maintain the corresponding knife in its retracted inoperative position while the operating member is moved to its second position. The selector mechanism includes a shaft carrying a plurality of cam elements which are mounted on the shaft and arranged to be moved to a position for blocking a respective spring loaded part upon rotation of the shaft from a non-holding to a holding position.

Abstract: A continuous baler having a movable section having an open mode and a closed mode. In the closed mode, the movable section is joined to a baling half chamber and a tying half chamber to form a baling chamber and a tying chamber, respectively. In the open mode, the movable section is moved away from the baling half chamber and tying half chamber, in order to allow passage of a bale formed in the baling chamber from the baling half chamber to the tying half chamber.

Abstract: A baler includes a housing forming a baling chamber. The baling chamber has an inlet that defines an inlet width perpendicular to a central longitudinal axis of the baler. A pre-cutter is disposed forward of the inlet along the central longitudinal axis and includes a cutter width perpendicular to the central longitudinal axis. The cutter width is substantially less than the inlet width. A crop distributor is disposed between the pre-cutter and the inlet and conveys the crop material from the pre-cutter to the inlet. A pick-up head is disposed forward of the pre-cutter and lifts the crop material from the ground and conveys it to the pre-cutter.

Abstract: A system and method of using a combination strapping machine including a wire tying system and a plastic tying system is provided. Embodiments of the strapping machine include a common frame coupled to a wire strapping system, a single wire track, a plastic strapping system, and a single plastic track. Some embodiments of the combination strapping machine include a strapping machine frame having a common track perimeter. Further, the strapping machine includes a plastic tying system configured to apply a plastic strap to a baled material, and a wire tying system configured to apply a wire strap to the baled material. Some embodiments of the strapping machine include a common track for the wire tying system and plastic tying system. Some embodiments of the strapping machine include a common frame for the wire tying system and plastic tying system with a non-common track.

Abstract: In one aspect, the present subject matter is directed to a method for maintaining a desired amount of residue coverage in a field during a tillage operation. The method includes generating, with a computing device, an available residue map that includes an amount of available residue at each location of the field using a yield map and/or crop biomass. The method also includes generating, with the computing device, a desired residue coverage map that includes a desired amount of residue coverage for each location within the field. Further, the method includes determining, with the computing device, an amount of residue that needs to be incorporated into the surface of the field based on the available residue map and the desired residue coverage map.

Abstract: A unit for conveying agricultural products including a device (3) for conveying agricultural products picked up by an apparatus (2) toward an inlet to a chamber (102) of an agricultural machine (100). The device (3) includes a main rotating shaft (4) facing the apparatus (2) and a plurality of teeth (5), and an auger (6). The auger (6) includes an auxiliary rotating shaft (7) facing the apparatus (2) and contiguous and substantially coaxial to the main shaft (4). A screw (8) is wound around the auxiliary shaft (7) to push the agricultural products toward the teeth (5). Each stem of a series of stems (9) is interposed between a first surface (8a) of the screw (8) and an inner end (7a) of the auxiliary shaft (7), for facilitated movement of the agricultural products propelled by the auger (6) toward the teeth (5).

Abstract: An agricultural baler system has a plunger, a bale chamber, a pre-compression chamber and a stuffer unit, for moving crop from the pre-compression chamber to the bale chamber. The stuffer unit includes a stuffer fork trigger mechanism, an actuator and a controller. The actuator is coupled to the stuffer fork trigger mechanism. The controller is in controlling connection with the actuator. The actuator is configured to arm the stuffer fork trigger mechanism by moving the actuator between a first position and a second position. The actuator is further configured to be held in the first position and/or the second position with substantially no energy use.

Abstract: A bale wrapper and a round baler with such a device are described. The bale wrapper comprises a supply device, extending along the width of a bale chamber of a round baler, for the introduction of wrapping material. The supply device comprises a shielding layer, located on its upper side, for the upper-side shielding of a free end of the wrapping material, to be introduced into the bale chamber. In order to improve the supply operation of wrapping material into the bale chamber, the shielding layer comprises several shielding lips, located parallel to one another along the width of the bale chamber, which extend in the direction of an interior of the bale chamber.

Abstract: A bale forming device forms a bale in a bale forming chamber surrounded by a casing. A discharge gate actuator moves a discharge gate from a closed position into an opened position. The formed bale is ejected out of the casing and drops onto a ramp. A ramp sensor detects the bale dropping onto the ramp and triggers the discharge gate actuator to stop opening the discharge gate.

Abstract: An agricultural baler including a bale chamber; a feeder duct communicating with the bale chamber; and a feeder operable within the feeder duct to accumulate a charge of crop material therein and then stuff that accumulated charge into the bale chamber. The baler further includes a conveying channel and a conveyor operable in the conveying channel to convey the crop material along a bottom wall of the conveying channel toward the feeder duct. The bottom wall of the conveying channel is adapted to be moved away from the conveyor; and the lower end part of the bottom wall of the feeder duct is attached to the movable bottom wall of the conveying channel.

Abstract: A repair, conversion or retrofit kit includes at least two continuously closable replacement baler belts which correspond substantially in their combined width to the width of a continuously closed baler belt to be replaced. The replacement baler belts may be closable in a force-fitting and/or form-fitting manner by a connecting means, and the connecting means may be at least partially hook connectors. In some embodiments, the repair, conversion or retrofit kit further includes at least one guide means arranged on the round baler such that at least two replacement baler belts each extend laterally with respect to the at least one guide means, and the at least two replacement baler belts are guided laterally with respect to one another. In some cases, the guide means is an auxiliary guide disk arranged on a rotatable shaft of the round baler.

Abstract: An apparatus for transferring agricultural products, for agricultural machines designed for the formation of a bale is provided. The transfer apparatus includes at least one impeller rotor, which can be arranged between a pick-up drum of agricultural products and a chamber for the compression of the agricultural products. The rotor is facing a deck, for delimiting at least partially a channel. The deck is coupled to a fixed frame by way of at least two supports which can move on command. At least one first support includes at least one support pin, which is coupled to a first portion of the deck and moved, in a corresponding guiding slot, by a corresponding actuator. At least one second support includes at least one crank, which is coupled to a second portion of the deck and rotatable about a rotation axis that is perpendicular to the advancement direction.

Abstract: An agricultural baler including a bale chamber, a feeder duct communicating with the bale chamber for charges of crop material to be transferred from the feeder duct into the bale chamber; and a feeder operable within the feeder duct to accumulate a charge of crop material therein and then stuff that accumulated charge into the bale chamber. There is an opening in the bottom wall of the feeder duct and at least one door hingedly attached to an edge of the opening, the edge being the edge of an end part of the bottom wall of the feeder duct, and the end part of the bottom wall to which the door is hingedly attached, is movably arranged relative to the top wall of the feeder duct.

Abstract: A square baler including a baling chamber having a floor formed of spaced profiles, side walls and a top wall, and a density belt surrounding the baling chamber. The density belt is formed of a U-shaped frame having three beams welded to one another to define a floor beam for supporting the floor of the baling chamber and two upright beams for supporting the side walls of the baling chamber and a tensioning rod releasably secured to the upper ends of the two upright beams to prevent the upright beams from splaying apart.

Abstract: An agricultural harvester (100) has a control system (166) that is configured to control a biomass harvesting rate based upon electronically calculated soil effects.

Abstract: An agricultural baler includes a main bale chamber, a plunger, a gear box, and a stuffer unit. The plunger is reciprocally movable within the main bale chamber. The stuffer unit is driven by the plunger and the gear box, and is movable through a stuffer cycle for transferring crop material in charges into the main bale chamber. The agricultural baler further includes a hydraulic brake associated with and configured for acting as a brake on the stuffer unit during a portion of the stuffer cycle.

Abstract: A wrap feed arrangement is disclosed for an agricultural harvester having a module-forming chamber. The arrangement includes a conveyor arrangement, which delivers crop to the module-forming chamber, and a module-forming arrangement which, at least in part, builds the module. The conveyor arrangement has a first roll and a first endless member disposed about the first roll for rotation. The module-forming arrangement has a second roll and a second endless member disposed about the second roll for rotation. At least one of the first and second rolls is movable from a first position in which the first and second endless members are disengaged to a second position in which the first and second endless members are engaged.

Abstract: A sensor detects a characteristic of accumulated crop material and a controller manipulates the speed of a baling chamber in response thereto. The speed of a baling chamber of a variable speed baler is manipulated in response to a characteristic of an accumulated crop material. For example, the height of accumulated crop material in an accumulation area may be detected and the speed of the baling chamber manipulated in response thereto. The rate of growth of the bale may also be determined and used in manipulating the speed of the baling chamber.

Abstract: A rectangular baler comprising a bale chamber delimited by a plurality of walls including a movable wall section, an actuator for exerting a pressure on the movable wall section, a plunger for compressing crop material in the bale chamber, and a density control system including: a position calculating module configured to calculate a new position for the movable wall section based on an input representative for bale density of compressed crop material in the bale chamber, and a position control module configured to control the actuator to position the movable wall section in the calculated position.

Abstract: A system for controlling the speed of harvested crop as it is discharged from a crop accumulator onto a field comprising a discharge mechanism for imparting a desired rearward travel speed to the harvested crop as it is being discharged from the crop accumulator and a speed measurement device for measuring forward travel speed of the crop accumulator. A processor is in communication with the discharge mechanism and the speed measurement device and is operable to adjust the discharge mechanism for imparting the desired rearward travel speed or the forward travel speed of the crop accumulator, to discharge harvested crop with a rearward travel speed that is substantially equal to the forward travel speed such that the harvested crop has a substantially net zero speed as it contacts the ground.

Abstract: In an example embodiment, a sensor detects a characteristic of accumulated crop material and a controller manipulates the speed of a baling chamber in response thereto. In an example method, the speed of a baling chamber of a variable speed baler is manipulated in response to a characteristic of an accumulated crop material. For example, the height of accumulated crop material in an accumulation area may be detected and the speed of the baling chamber manipulated in response thereto. The rate of growth of the bale may also be determined and used in manipulating the speed of the baling chamber.

Abstract: The present invention is a rake, comprising a tongue assembly and a wheel assembly operably coupled to the tongue assembly and being rotationally shiftable relative to the tongue assembly and the wheel assembly mounting a pair of rake assemblies. Each of the pair of rake assemblies is disposable in a generally horizontal disposition when the rake is in a transport disposition, the generally horizontal disposition being effected in part by the rotational shifting of the wheel assembly when transitioning between a working disposition and the transport disposition. The present invention is further a method of disposing the aforementioned rake in the transport disposition.

Abstract: A bale density adjustment system for adjusting the density pressure on bale during formation comprising: a bale chamber, at least a first density adjuster, at least a first weight sensor, at least a first diameter sensor, at least a first operator interface, and a controller, in operable communication with and configured to process digital and/or analog information from the at least first weight sensor, the at least first diameter sensor, the at least first density adjuster, and the at least first operator interface.

Abstract: A square baler has a baling chamber, a plunger reciprocable at one end of the baling chamber, a pre-compression chamber within which charges of crop are amassed and pre-compressed by a rotor prior to transfer into the baling chamber, and a pickup roller having radially projecting tines for picking up crop from the ground and advancing the crop to the rotor. A torque sensor is connected to at least one tine of the pickup roller to produce an electrical output signal indicative of the torque experienced by the pickup roller, and a processing circuit is operative to estimate the rate of crop flow into the chute by analyzing the electrical output of the torque sensor only at times when the position of the tine lies within a predetermined angular position of the pickup roller.

Abstract: An improved belt tensioning system for an agricultural round baler that increases belt tension to reduce slippage between the belts and the driving rolls during the initial stage of a bale forming cycle when the bale chamber is empty and as the belts are beginning to be rolled. The system includes an accumulator that is pressurized by the tensioning system as a bale is being formed. The accumulator pressure may then be directed to a hydraulic cylinder included in a bale density system to increase tension in the belts after a completed bale is ejected and the bale chamber is being reset for the next bale.

Abstract: Agricultural baler with feeder system arranged for repeatedly feeding crop material towards a baling chamber, the feeder system includes a feeding chamber and a stuffer. The feeder system is arranged for collecting a crop material. The stuffer is arranged for repeatedly carrying out a stuffing cycle and varying an entry position and/or an exit position and/or a stroke depth. The feeder system further includes a sensor arranged for generating a signal indicative of the accumulated crop material in the feeding chamber. A controller that is arranged for triggering the stuffer to start a stuffing cycle wherein the entry position, the exit position, and/or the stroke depth, is adjusted in response to an indication by the sensor signal of the accumulated crop material in the feeding chamber.

Abstract: A harvester assembly has a feeder assembly, a bottom floor assembly, and a crop collection channel. The rear portion of the bottom floor assembly is capable of variable movement to facilitate the passage of crop material through the crop collection channel with a reduced risk of clogging or plugging of the channel.

Abstract: A web wrap device is provided for a round baler. The device has a web carrier for pulling the web from a roll of web to a bale chamber. In a leading portion the web carrier has two elements at least one of which being moveable towards the other. The moveable element has a leading edge, which engages the web and is pulled by the tensioned web onto the other element, which increases the clamping effect. In addition a guard is provided to cover a knife during the wrapping mode, but to expose the knife to the web, when it should be cut.

Abstract: A baler apparatus includes a baling chamber including a channel including an inlet end and an outlet end, a reciprocating plunger adjacent the inlet end of the baling chamber that is operable to compress a body of bale material within the baling chamber, a binding device for binding the compressed body of bale material to form a bale, and at least one adjustable wall for adjusting the compression of the bale material during formation of a bale.

Abstract: An improved belt tensioning system for an agricultural round baler that temporarily bypasses a bale density, belt tension increasing system while the baler tailgate is moved out of a closed position thereby allowing the tailgate to be opened without encountering resistance form the belts and the belt tensioning system. Bypass operation is coordinated with the tailgate position so that the bypass is not activated when such activation would frustrate operation of the belt tensioning system. In balers equipped with a belt tensioning pre-tensioning system, the bypass operation is further coordinated with the pre-tensioning system to maintain proper pre-tension function.

Abstract: An agricultural round baler has an electronic control unit (ECU), a bale diameter sensor, a gate position sensor, and an electro-hydraulic valve that controls the flow to the gate lift cylinder. The ECU determines the height to which the gate must be raised based on the bale diameter. When the gate reaches the desired height, the ECU closes or restricts the electro-hydraulic valve for a brief period of time thereby momentarily slowing or stopping gate the gate. Momentarily trapping the bale between the gate and ground allows the bale to come to rest before the bale is released from the baler. The gate can then be fully opened so that the tractor and baler can be moved clear of the bale before closing the gate.

Abstract: A combined baler/bale wrapper (1) comprises a chassis (5) on which a baler (10) and a bale wrapper (11) are mounted. The baler (10) comprises a stationary segment (18), a lower segment (19) and an upper segment (20) which together define a bale forming chamber (15) within which a round bale (2) is formed. The lower segment (19) and the upper segment (20) are pivotal from a bale forming position (FIG. 5) to a discharge position (FIG. 1) for transferring a bale of the bale forming chamber (15) onto bale supporting rollers (50) of the bale wrapper (11). The bale supporting rollers (50) rotate the bale (2) about a first wrapping axis (53) while a carrier ring (55) simultaneously revolves a pair of wrapping material dispensers (54) about a second wrapping axis (56) for dispensing wrapping material onto the bale (2).

Abstract: An improved baler and a method of using the improved baler to produce high density bales. The baler comprises a pick-up assembly configured to pick-up crop material; a compression assembly comprising at least one pair of opposing compression rollers configured to generate a pressure on the crop material sufficient to crush the nodes as it passes between the compression rollers; and a bale chamber, wherein the crushed crop forms a bale. The compression rollers define an adjustable gap therebetween. By adjusting the gap, a pressure sufficient to crush the nodes of the crop may be exerted on the crop material as it passes between the compression rollers may be controlled, resulting in bales of higher density than conventional bales.

Abstract: A baler comprises a pick-up assembly configured to pick-up crop material; a compression assembly comprising at least one pair of opposing compression rollers configured to generate a pressure on the crop material as it passes between the compression rollers; and a bale chamber, wherein the pre-compressed crop forms a bale. The compression rollers define an adjustable gap therebetween. By adjusting the gap, pressure exerted on the crop material as it passes between the compression rollers may be controlled, resulting in bales of varying density.

Abstract: The invention relates to a wrapping device to wrap an object in foil material including a frame, a wrapping table mounted on the frame and configured to support the object during wrapping, one or more roll support devices to support one or more rolls of foil material to be rotated about the object during wrapping, a carrying structure mounted on the frame and configured to carry the one or more roll support devices, and a clamping and cutting device to clamp the foil material after wrapping of an object, and to cut the clamped foil material, wherein the clamping and cutting device is mounted on the carrying structure, and wherein the carrying structure is pivotable about a substantially horizontal pivot axis with respect to the frame.

Abstract: In a method for operating a round baler, the harvested crop flow is controlled at any time of the bale forming process by time control with the control and governing device of the round baler, based on a stored theoretical minimum time for pressing a harvested crop bale defined by predetermined parameters and based on actually determined harvested crop parameters, such that the harvested crop bale defined by the predetermined parameters is produced at maximum baler utilization in a nominal press time determined for the harvested crop bale.

Abstract: A conveyor system that may be used with an agricultural harvester, such as a round baler, waste baler, combine, sugarcane harvester or cotton harvester. More particularly, the conveyor system utilizes at least a first and a second conveyor belt of which at least one of the conveyor belts is independently movable in the forward and backward directions. The speed and direction of the conveyor belts can be controlled to perform continuous baling of harvested crop in the agricultural baler.

Abstract: A baler for agricultural material including a reciprocating plunger that compresses crop material in a channel into flakes which are stacked to provide a bale length of the desired size. The baler is towed from and powered by a steerable tractor having an operator display. The channel receiving the plunger has right and left walls which support star wheels having points projecting into the channel for the flakes and bale. The relative movement of the bale from right to left is determined and indicated to the operator of the vehicle to steer right, left or straight to ensure that bales have thickness that is uniform across their width.

Abstract: A crop harvesting system for continuous round baling is described that comprises a first and second bale chamber and a conveyor system in operable communication with the first and second bale chambers. The crop harvesting system can comprise at least three bale carriers, at least two serpentine systems to facilitate movement of the bale into and out of the first and second bale chambers. The crop harvesting system can be integrated into an agricultural harvester such as a baler or combine.

Abstract: The present invention relates to a hydraulic circuit mechanically linked to a panel and agricultural harvesters comprising the same. The hydraulic circuit of the present invention can be used to facilitate the transition of hydraulic states from a quick speed to a slow speed, when opening and closing the panel. The hydraulic circuit comprises a fluid stop valve comprising a restrictive orifice which, when narrowed, reduces the rate of pressurized fluid flow into a hydraulic actuator during the actuator's extension. The reduced flow of pressurized fluid into the hydraulic cylinder substantially reduces the speed at which the panel opens or closes.