in one embodiment shown in fig1 - 6 , lawn and garden tractor 10 may have front wheels 11 , rear wheels 12 , mower deck 13 suspended from the vehicle frame between the front and rear wheels , and grass collection container 14 mounted at the rear of the vehicle . at least one surface , or a portion of one or more surfaces , of collection container 14 may be an air permeable material , such as a mesh or screen . mower deck 13 may cover one or more cutting blades to cut and propel grass clippings into a material collection system . the material collection system may include discharge chute 15 extending rearwardly between an opening in mower deck 13 and grass collection container 14 . optionally , the material collection system may include an auxiliary blower or fan which may be mounted in a housing adjacent discharge chute 15 to help propel grass clippings through the duct into grass collection container 14 . in one embodiment , material collection system may have a rear discharge , rear collect configuration . for example , the mower deck may have two counter rotating cutting blades which force the grass clippings through a discharge chute located under the operator &# 39 ; s seat . the grass clippings may exit the discharge chute and enter the collection container that the operator may tip and dump from a seated position . however , the material collection system sensor also may be used on lawn and garden tractors having decks with three or more cutting blades . additionally , the material collection system sensor may be used on other types of grass mowing machines including but not limited to zero turning radius mowers . in one embodiment shown in fig1 - 6 , the material collection system sensor may include paddle 20 which may be a sheet metal or plastic member having a first or forward end 22 and a second or rearward end 24 . the paddle may have a width of between about 10 mm and about 50 mm , and a length of between about 200 mm and about 600 mm . the rearward end of the paddle may be pivotably mounted to tunnel 35 with pin 25 , so that the forward end of the paddle may have a maximum displacement ( upwardly and downwardly ) of at least about 10 mm and less than about 50 mm . in one embodiment , the material collection system sensor may include tunnel 35 which may be a sheet metal or plastic member mounted to the inside floor 28 of the collection container , preferably near the middle between the left and right sides of the collection container . the tunnel may provide an inclined surface above the generally flat and substantially planar inside floor surface of the collection container . the tunnel may have width and length dimensions substantially corresponding to the paddle width and length dimensions . the first or forward end 30 of the tunnel may be positioned on the inside floor adjacent the front of the collection container , and the second or rearward end 32 may be on the inside floor adjacent the rear or back of the collection container . the top surface 34 of the tunnel may be inclined or sloped upwardly from the forward end to the rearward end , and the underside of the tunnel may provide an open or hollow recess . in one embodiment , as shown in fig5 - 6 , hydraulic dump cylinder 40 may be positioned in the recess within the underside of the tunnel when the collection container is in the lowered or collection position . a forward end of the dump cylinder may be connected to frame assembly 42 attached to the rear of the lawn and garden tractor . a rearward end of the dump cylinder may be connected to rear support member 44 of the collection container near the rearward end of the tunnel . more specifically , the second end of the dump cylinder may be connected to a cross member of frame assembly 42 , under the floor of the collection container . the dump cylinder may extend to dump the collection container when it is in a raised position . in one embodiment , the material collection system sensor may include switch 50 . the switch body may be snap mounted to the tunnel below the top surface of the tunnel , and the switch may include button or actuator 51 projecting above the top surface of the tunnel where it may be contacted by paddle 20 . the paddle may contact and actuate the switch when the collection container fills with material . the switch may have a push button or plunger type switch actuator that may be spring biased to a normally open position and that requires motion of about 0 . 040 to about 0 . 150 inches to make or break contacts . an example of a switch is shown in u . s . pat . no . 4 , 812 , 604 . the switch may be connected by wiring harness 52 to visible or audible fullness indicator 54 in the operator station of the lawn and garden tractor . in one embodiment , grass clippings or other material may accumulate on paddle 20 to move the paddle downwardly sufficiently to actuate the switch . the displacement to actuate the switch may be at least about 5 mm and less than about 25 mm . this may be the required paddle displacement near the middle of the tunnel where the switch is positioned . the switch may be located in a fore and aft position near the middle of the tunnel between the tunnel &# 39 ; s forward and rearward ends . top surface 34 of the tunnel may provide a stop which limits downward displacement of the paddle . lip 70 on the forward end of the paddle may provide a stop that limits upward displacement of the paddle , because lip abuts forward end 30 of the tunnel . in one embodiment , the material collection system sensor may include sensitivity adjuster 58 attached by snap mounting to the underside of tunnel 35 and under the paddle near the paddle &# 39 ; s forward end . the sensitivity adjuster may include sensitivity adjustment knob 60 which may be rotatably mounted with bracket 66 to the outer bottom surface of the collection container . for example , the sensitivity adjustment knob may be attached to the lower end of captive screw 64 extending through openings in tunnel 35 and the bottom surface of the collection container . when the collection container is in the lowered or collection position , the operator may reach under the collection container to change the sensitivity setting using the sensitivity adjustment knob . when lift cylinder 40 is used to raise the collection container to the dump position , the operator may reach and change the setting of the sensitivity adjustment knob . bracket 66 also may include a guard extending from the bottom of the collection container that provides a protective structure adjacent the sensitivity adjustment knob . in one embodiment , sensitivity adjuster 58 may include spring 68 which may be seated on bushing 71 that rides on captive screw 64 in the recess under the tunnel . the spring may extend upwardly through the recess under the tunnel to contact and / or engage slot 72 on the paddle surface adjacent the paddle &# 39 ; s forward end . the spring may urge or bias the forward end of the paddle upwardly . the operator may turn sensitivity adjustment knob 60 to rotate captive screw 64 and raise bushing 71 up and toward the paddle and compress the spring , or down and away from the paddle to relax the spring . as a result , the sensitivity adjustment knob may be used to change the spring force and thus the sensitivity of the material collection system sensor . in one embodiment , the operator may turn sensitivity adjustment knob 60 in a direction to compress the spring and lower the sensitivity of the fill sensor so that more material , or material with an increased density such as wet grass clippings , may be required in the collection container to displace the paddle sufficiently to actuate the switch . the operator may turn sensitivity adjustment knob 60 in the other direction to relax the spring and increase the sensitivity of the fill sensor so that less material , or material with a lower density such as dry grass clippings , is required in the collection container to displace the paddle sufficiently to actuate the switch . having described the preferred embodiment , it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims .
a material collection system sensor includes a paddle pivotably mounted to a tunnel on a collection container floor . the forward end of the paddle is adjacent a front of the collection container and the rearward end is adjacent a rear of the collection container . a switch mounted to the tunnel under the paddle has an actuator extending above the tunnel that is actuatable by downward pivotal movement of the paddle . a sensitivity adjuster attached to the tunnel under the paddle has a sensitivity adjustment knob outside the collection container which compresses or relaxes a spring extending upwardly against the paddle .