CA2022504A1 - Mower variator control mechanism - Google Patents
Mower variator control mechanismInfo
- Publication number
- CA2022504A1 CA2022504A1 CA 2022504 CA2022504A CA2022504A1 CA 2022504 A1 CA2022504 A1 CA 2022504A1 CA 2022504 CA2022504 CA 2022504 CA 2022504 A CA2022504 A CA 2022504A CA 2022504 A1 CA2022504 A1 CA 2022504A1
- Authority
- CA
- Canada
- Prior art keywords
- rod
- flange
- lever
- reverse
- spring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Gear-Shifting Mechanisms (AREA)
Abstract
Abstract The shift mechanism utilizes a foot pedal to control the movement of the lawn tractor to the limit preset by a speed lever. A spring loaded shift mechanism causes a dog clutch to be spring biased against forward and reverse gears upon shifting when such are not in engaging alignment.
Description
20~250i MOWER VARIATOR CONTROL MECHANISM
This invention relates to a variator control mechan'ism for a lawn mower.
Background Of The Invention Lawn mowers are considered by many to be a necessary part of suburban life. Typically these lawn mowers include a vertical shaft engine (mounted in either the front or back part of the lawn mower) driving a cast aluminum transaxle and a mower deck through separately clutched belt drives. The transmission is normally either a continuously variable transmission (such as a variable belt or hydraulic drive) or a multi speed mechanical transmission (such as a selectable gear drive). The control of these transmissions and the other operative parts of the mower are occasioned through a combination of rods, levers and wires which lead to cantrols in the operator station for the lawn mowers. The control 7:
mechanisms in their entirety are complex. In addition the cooperation and manipulation of these controls is frequently fought with much uncertainty and confusion on the part of the operator. ;
.. , ' '''~'" ' ObLects Of The Invention lt 18 an ob~ect of ttl1s ln~tltLon tv provLd~ t~r ~n improved operator control of a variable transmission.
It is an object of this invention to provide an immediate shift capability to a transmission having fixed teeth dog clutches.
IPge~
- ~02250~ 1 It is an object of this invention to increase the serviceability of lawn mowers.
. ' It.is an object of this invention to reduce the ..
complexity of the controls for lawn mowers.
It is an object of this invention to provide for a reliable interlock to prevent operation of reverse while the mower is engaged. ~
Other objects and a more complete understanding of the invention may be had by referring to the drawings in which:
Drawinqs Figure 1 is a perspective breakout view of the drive .-train of a lawn mower incorporating the invention of the application;
Figure 2 is a top view of the spring loaded dog . .
clutch shift interconnect mechanism for the transmission of the - -lawn mower of Figure l;
Figure 3 is a side view of the interconnect of Figure - . -2;
Figure 4 is a cut away cross sectional view of part of a transmission incorporating the interconnect of Figure 2; ... j.--.. .--Figure 5 is a series of representati.onal views of the spring loaded interconnect mechanism and the dog clutch of Figure 4 showing various operating positions thereof; :-: .
Figure 6 iiY a side view of the speed and direction : -operator controls of the lawn mower of Figure l; and, Figure 7'is a side view of the main operating control :~.
detailing the interconnection of the reverse interlock. : . .
l , ',, l Page #2 .-~ ~ 22~
Description Of The Drawinqs This invention relates to improved operator controls.
The in~ention will be described in its preferred embodiment of operator control for a rear engine, front control lawn mower.
Other engine and control placements could also be utilized with the invention.
The lawn mower 20 has a body 21, a transmission 22, a separate variator drive mechanism 23, and operator station controls 24 (Figure 1).
The body 21 provides a physical support and locating means for the remainder of the parts of the lawn mower 20. The particular body 21 shown is a stamped steel frameless member having integral reinforcing flanges 30 and access cutouts 31.
The flanges 30 are designed so as to strengthen the rigidity of the stamped steel sections of the body 21. The cutouts 31 are designed in order to provide either physical access to or ~ -physical space for other parts of the lawn mower 20. Other body designs with or without separate frames could also be utilized as appropriate.
The transmission 22 for the lawn mower 20 selectively interconnects the engine 35 to the ground engaging wheels 36.
The particular transmission 22 shown in the preferred embodiment is a forward--neutral--reverse shift transmission - -having a reduction gear train and differential for use with a separate variator speed mechanism 23 (later described).
~Integral speed features could be incorporated into the transmission if desired--i.e. multiple gears, integral variator, hydrostatic, etc.) The particular transmission 22 disclo~ed ha~ a slideable dog clutch 39 located on a central ¦ Dg~ ~3 ~ ~
~ ~ 20~0~
rotatable drive shaft 40 between the forward 37 and reverse 38 gears for the transmission 22 (Figure 4). These two gears 37, 38 are'in constant mesh with an input bevel gear driven by the shaft 53 for providing oppositely rotating gears on the shaft 40. The teeth 34 of the dog clutch 39 selectively engage holes 41 in either the forward 37 or reverse 38 gears in order to interconnect same to the drive shaft 40 and th.us provide for forward and reverse operations of the transmission 22. There is a gear 36 on the rotatable shaft 40 that in turn drives the reduction gear (and output axles) of the transmission 22. Note that in the particular transmission 22 disclosed, the teeth 34 of the dog clutch 39 do not retract. This particular construction allows the dog clutch 39 to be made stronger than would be possible in the same space had retractable spring loaded teeth been utilized instead. This presents problems and advantages later discussed. If desired other transmissions including those having integral variable speed mechanisms (meshing gear, hydrostatic, etc.) could be utilized with the invention.
The variator mechanism 23 is connected between the engine 35 and the transmission 22 in order to selectively ;~ ;
interconnect the same (Figure 1). In the particular embodiment -shown, the preferred variator mechanism 23 is a belt mechanism incorporating both variable speed and selective clutching attributes. This variator mechanism 23 utilizes a fixed diameter input pulley 42 journaled on the output shaft of the -engine 35. This pulley 42 is connected by a belt 44 to the variator pulley 43. This variator pulley 43 itself mounted in a fixed location to the body 21 of the lawn mower 20. This . . ,.,..
' Page #4 . , : , , .: , :. .
21)22~0~ 1 variator pulley 43 includes two variable diameter sheave~ 56, 57. The belt 44 from the engine 35 is connected to the upper sheave ~6 of the variator pulley 43. The belt 44 also is fed about the pulley 45 which is mounted to the end of a moveable arm 49. The effective length of this belt 44 is adjusted through the use of selective movement of this arm 49 (as later described). A spring 47 biases the arm 49 (and,thus the belt 44) into its high speed engaged position (as later described).
The upper sheave 56 of the variator pulley 43 is n~ <~-7 rr~)n~ w-~r ~l~a;~v~ r~-7 ~f l l~o vn~ tr r t~ v movable element 50. The movement of this element 50 alters r~lationship between the effective, diameters of the two sheaves 56, 57 of the variator pulley 43. The lower sheave 57 of the variator pulley 43 is interconnected ,to the input shaft 53 of the transmission 22 by a second belt 52 interconnecting to a large diameter pulley 54 interconnected to such input shaft 53.
A spring loaded idler mechanism 55 mounted on the pivoting arm 46 insures that this second belt 52 is under constant tension.
With this variator mechanism, movement of the arm 49--i.e. movable pulley 45--directly alters the relative speed of the input shaft 53 of the transmission 22 in respect to the speed of the pulley 42 on the engine 35 by altering the ratio ,-of the diameters of the upper sheave 56 to lower sheave 57,of the variator pulley 43. The actual movement of the arm 49 is accomplished through the use of a rod 48 which interconnects , directly to the arm 67 off of the pedal 60 at the operator -station controls 24. Upon forward positioning of the pedal 60, "~
the belt 44 has no tension such that the pulley 42 of the ¦ engine 35 rotates freely of the variator mechanism 23--i.e. the ,' age S
. 1 ~, J --2022~0~
¦ drive is declutched. Upon movement of the pedal 60 rearward the rod 48 also moves rearward. The spring 47 facilitates this movement. The rearward movement of the rod 48 in turn engages and then begins to shorten the effective length of the belt 44 between the engine 35 and variator pulley 43. This first engages the drive between engine and transmission--i.e.
clutches the lawn mower drive. Subsequent move~ent of the pedal 60 further tightens the belt 44. This causes the movable element 50 of the variator pulley 43 to move downwards. This in turn alters the diameters of the sheaves 56, 57 and thus lengthens the effective length of the second belt 52 between the variator pulley 43 and the input shaft 53 of the transmission 22. In combination this action reduces the ~ -relative ratio of speed between the engine 35 and the input -shaft 53 of the transmission 22--i.e. increases the mowers -speed of travel. Upon movement of the pedal 60 forward, the -rod 48 moves forward (and thus the movable pulley 45 inwards) in order to lengthen the length of the belt 44. This in turn increases the size of the top sheave 56 and reduces the size of -the bottom sheave 57 of the variator pulley 43 in order to increase the ratio of speed of the transmission pulley 54 in respect to the engine pulley 40--i.e. reduces the mowers speed --of travel. Eventually the belt 44 is relieved of tension and -the drive between engine and transmission is again ~ --disengaged--i.e. the lawn mower drive is declutched. -The forward/reverse movement of the rod 48 is under the operator's control at the operator station 24. The operator station controls 24 include a main foot pedal 60, a ¦ Page :6 , ,, ~ , .... . . . . . . .. . .. .. . . . .
1 202~0~
¦ lever 61, a power takeoff lever 62, and a parking brake 63 (Figures 1, 6 and 7).
The foot pedal 60 is the main operational control for the lawn mower 20. This foot pedal 60 controls the speed of the lawn mower 20 including braking functions The foot pedal 60 shown accomplishes this operational control through the use of a rotating rod 64 located underneath the body 21 of the mower. The speed rod 48 is attached to a hole in the extension arm or bracket 65 of the rotating rod 61 such any rotary movement of the foot pedal 60 is transferred directly into a corresponding forwardtreverse axial movement of the rod 48 (from the default spring loaded rqarward position of the rod 48 application of the foot pedal 60 pulls such rod 48 forward). A
brake rod 66 is interconnected into a slot 67 in the same extension 65 of the foot pedal 60 such that on the forward positioning of the foot pedal 60, the brake rod 66 is pulled forward to apply the brake. The slot 67 which interconnects the brake rod 66 to the part 65 of the rotating rod 64 thus - :
allows for a lost motion interconnection such that the brake is disconnected from the foot pedal 60 for most of the travel ~-thereof. A spring 69 located between the brake rod 66 and the actual braking mechanism 68 on the transmission 22 allows for a mechanical interconnection therebetween such that there is a modicum of over travel on the foot pedal 60 after the brakes are applied. This over travel allows the bottom section 70 of the parking brake rod 63 to be selectively engaged with a hook 71 extending off of, another extension 72 of the rotating rod 64 to hold the foot pedal 60 forward and the brake rod 66 in an engaged parking position upon the downward positioning of the Page 7 ¦
."~.' "
2022~0~ 1 parking brake rod 63. Note that except for shifting the transmission into reverse, the foot pedal 60 controls the directional operation of the lawn mower 20--i.e. clutching, speed of travel, and braking functions. (The preferred embodiment has only one reverse speed. In other embodiments multiple reverse speeds could be provided if desired.) The speed of forward travel and the.reverse shifting for the preferred transmission 22 is controlled by the reverse 1-shift--forward speed preset shifter control 85. This control -85 is rotatively connected to the body 21 of the lawn mower.
The control 85 is mechanically interconnected to the forward speed rotating rod 64 ~and thus the foot pedal 60) via a rod 80 interconnecting a slot 81 in the control 85 with a hole 82 in the other extension 72 of the speed rotating rod 64. The positioning of the preset control 85 is thus able to limit the rearward motion of the rotating rod 64 after a certain predetermined point. The predetermined point is set by the preset lever 87. This forward speed preset lever 87 is ~-rotatively mounted to the body 21 of the lawn mower neighboring the lever 61 of the control 85. In use the operator determines ~-initially what maximum speed he desires to operate the lawn - :
mower. The operator then sets the preset lever 87 into the appropriate one of the slots 86 in the body of the lawn ~ower immediately adjacent to the preset lever 87. The position of this preset lever 87 determines the maximum angular rotation of the control 85 (and thus the rotating rod 64) by allowing such control 85 to move no further forward than the physical positioning of the lever 87. In the embodiment disclosed, the I ; ~: ~
Page #8 , -. ' , `- - 2022~0~ 1 more forward the slot 86 for the lever 87, the higher the maximum preset forward speed of the lawn mower.
' In use the operator begins with the foot pedal 60 in a forward braked position. Upon release of the foot pedal, the rotating rod 64 and the extension 65 of the pedal control rod move backward. This releases the brakes via movement of the brake rod 66. The rod 80 (interconnecting with the front of the hole 82 of the other extension 72) also begins to move the reverse shift/forward speed preset control 85 forward.
Eventually the lever 61 of the control 85 will contact the speed preset lever 87 (previously positioned by the operator).
At this point the control 85 will not move further. When the hole 82 in the extension 72 contacts the rod 80, this rod 80 then cannot move backwards any more and the movement of the rotating rod 64 is ceased. This causes the lawn mower to proceed in the speed set by the forward speed preset lever 87. -If the operator wants to go faster than this speed, the operator pushes in the foot pedal 60 slightly to release the tension between the lever 61 of the control 85 and preset lever 87 and moves the preset lever 87 to a more forward slot 86.
Upon release of the foot pedal 60, the lawn mower will proceed at the higher rate of speed. Similarly the speed can be reduced by moving the speed preset lever 87 backward into a more rearward slot 86.
In order to place the lawn mower into reverse, the lever 61 of the control 85 is pulled backwards. This backward ;
motion o the control 85 moves a bearing 89 in a slot 88 to cau~e movement of the lever 90 from its normal forward gear ¦ po~ition to a rearward reverse gear position. This causes the ¦ Page #9 202~50~ 1 forward--neutral--reverse lever 91 of the transmission 22 to switch between its forward and reverse conditions (by a shift mechanism later described). Note that there is a notch 93 that interconnects with the power takeoff lever 62 in order to prevent the movement of the control 85 into a reverse position while the power takeoff 62 is engaged (Figure 7). This reverse interlock feature is accomplished by having a rod 94 extend from an extending portion 95 of the power takeoff lever upwards adjacent to the notch 93 on the control 85 such that when the po~er takeoff lever 62 is in its rearw~rd n~n-o~ od p~tl~n, ~- --there is a clearance between the end 96 of the rod 94 and the notch 93. When these two parts are in this orientation, the lever 61 can be moved backwards into its reverse gear selection -position without opposition~ However upon movement of the power takeoff lever 62 forwards into an engaged condition (as shown in Figure 7), the end 96 of the rod 94 is moved upwards such that such end 96 is within the arc traced by the notch 93.
Thereafter upon attempted motion of the control 85 backwards to engage reverse gear, the notch 93 will engage the end 96 of the -rod 94 prior to the transmission 22 being switched into its reverse condition. This interconnection prevents the engagement of the reverse condition of the transmission 22 while the power takeoff lever 62 is engaged. The net effect is -that an operator is unable to operate the machine in reverse without first disengaging the power takeoff lever 62.
The positioning of the forward speed preset lever 85 :
does not have any effect on the reverse speed of the lawn mower 20 which is set at a single 8peed in this preferred embodiment I . , ',' ,~''' I . ' ~:' ¦ Page #10 , . .:,, . , -.. . .. . . .
~- ~ 202~
(in other embodiments multiple speeds could be provided if desired with or without usage of the control 85).
The forward--neutral--reverse lever 90 is interconnected with the forward--neutral--reverse lever 91 of the transmission 22 through a lost motion spring loaded shift mechanism 100 (Figures 2-5). This shift mechanism 100 is designed to allow the shifting of the transmission 22, which has a fixed teeth dog clutch, between forward gear and reverse gear drive states without first aligning the teeth 34 of the dog with the notches 41 in the gears.
The shift mechanism 100 begins with a rod 101 that is connected between the lower end of the forward--neutral--reverse léver 90 such that any rotary movement of the lever 90 is transferred into axial movement of the rod 101. The other end section of the rod 101 is in turn connected at the rear of the lawn mower to a pivoting arm 102 which is pivotally bolted to a flange 103 extending off of the transmission 22. The bolts 112 to connect this flange 103 to -the transmission 22 are the same bolts used for as the brake -mechanism 68. This reduces the number of parts for the shift - -mechanism 100 as well as allowing it to be incorporated into -the transmission 22 without need for special mounting holes, -etc. (This allows an existing transmission to be utilized.) The direct connection of the flange 103 to the casting of the ~-transmission 22 insures that there is a minimal dimensional tolerance problem for the mechanism 100. The arm 102 in turn pivots around a bolt 104 such that forward and backward axial movement of the rod 101 is transferred into side to side movement of a ~mall tab 106 which extends downwardly off of the ~dge~
,, , , . , ,,,, .,~"", ", ., , " . . " . ", " , ~ , .
. . . .. . . . ..
- 202250~ 1 l arm 102. The tab 106 in turn has a hole 107 in the center ¦ thereof through which a further rod 108 or actuation piece extends. One end 109 of this rod 108 is pinned to the forward--neutral--reverse lever 91 on the transmission 22 for movement therewith. The other end 110 of the rod 108 has a nut 111 on it. The flange 106 is located on the rod between the two ends thereof. There are two springs 114, 115 which extend about the rod 108 on either side of the flange 106 thereof.
In a neutral position the flange 106 is located substantially in the middle of the rod 108 between the two ends 109 and 110 (see position A of Figure 5). (The fact that the end 109 of the rod 108 is adjustable through the nut 111 allows this neutral position to be preset during initial manufacture and subsequently). Upon movement of the rod 101 into a forward position, the flange 106 is moved to the right against the pressure of the spring 115 ~see position B of Figure S). At :
this time the dog 39 in the transmission is urged against the forward gear 37. If the teeth 34 of the dog clutch 39 are not ~
perfectly matched with the hole 41 in the forward gear 37, the ;-dog 39 will not drivingly engage the gear 37. The spring 115, however, biases the teeth 34 into engagement with the gear 37. :' Upon release of the foot pedal 60, the dog 39 begins to rotate -and with rotation comes the alignment of the teeth 34 with the hole 41 in the forward gear 37. At this point the teeth 34 engage the hole 41 so as to drivingly interconnect the dog 39 with the gear 37 (position C of Figure 5). This is the forward condition of the transmission. Upon shifting of the transmission back into a neutral condition (position D of ¦ Figure 5), the teeth 34 will normally disengage from the gear age tl2 ~ '- ~ 2~Z2!j~
37. Under certain circumstances, however, this may not occur.
Since this shifting condition also produces the neutral posi*~on o~ the main drive clutch for the entire unit, the fact that the dog 39 might not be disengaged from a gear is of no importance. However upon shifting of the transmission into reverse (position E of Figure S), the spring 114 will be physically collapsed into a solid mass such th~t there will be a solid interconnection between the flange 106 and the end 109 of the bolt 108. At this time any further movement of the flange will physically move the dog 39 out of engagement with the forward gear 37 and move its teeth 34 into spring loading biased position in respect to the reverse gear 38 ~position F
of Figure S--this is equivalent to position B in respect to a ~-forward condition. If the dog 39 is already disengaged from the forward gear 37, the movement will move the dog 39 into the same spring loaded biased position in respect to the reverse gear 38). At this point release of the clutch will again cause the dog 39 to begin rotating to align the teeth 34 with the - -hole 41 (if not already aligned) and thus drivingly engage the dog 39 with the reverse gear 38. Note that in all of this shifting it is not necessary for the dog 39 to be in driving engagement with either the forward 37 or the reverse 38 gear in order for the control 85 (and interconnecting parts including the flange 106) to be positioned in a forward or reverse position. This allows shifting between forward, neutral and reverse at any time. Note also that due to the physical size of the compacted springs 114, 115, it is impossible for the flange 106 to be shifted into either a forward or reverse condition while the oppo~ite gear 37, 38 is still engaged with .
Page #13 ~ ~_ ` 202250~ 1 the dog 39. This mechanism thus provides for forward--neutral--reverse fixed position shifting of a transmission in a non-synchronized dog clutch type mechanism.
Although the invention has been described in its preferred form with n cortnill ~e~ree ~f p.~tic~ r11y, be understood that numerous changes can be made without deviating from the invention as hereinafter claimed.
Page ~14
This invention relates to a variator control mechan'ism for a lawn mower.
Background Of The Invention Lawn mowers are considered by many to be a necessary part of suburban life. Typically these lawn mowers include a vertical shaft engine (mounted in either the front or back part of the lawn mower) driving a cast aluminum transaxle and a mower deck through separately clutched belt drives. The transmission is normally either a continuously variable transmission (such as a variable belt or hydraulic drive) or a multi speed mechanical transmission (such as a selectable gear drive). The control of these transmissions and the other operative parts of the mower are occasioned through a combination of rods, levers and wires which lead to cantrols in the operator station for the lawn mowers. The control 7:
mechanisms in their entirety are complex. In addition the cooperation and manipulation of these controls is frequently fought with much uncertainty and confusion on the part of the operator. ;
.. , ' '''~'" ' ObLects Of The Invention lt 18 an ob~ect of ttl1s ln~tltLon tv provLd~ t~r ~n improved operator control of a variable transmission.
It is an object of this invention to provide an immediate shift capability to a transmission having fixed teeth dog clutches.
IPge~
- ~02250~ 1 It is an object of this invention to increase the serviceability of lawn mowers.
. ' It.is an object of this invention to reduce the ..
complexity of the controls for lawn mowers.
It is an object of this invention to provide for a reliable interlock to prevent operation of reverse while the mower is engaged. ~
Other objects and a more complete understanding of the invention may be had by referring to the drawings in which:
Drawinqs Figure 1 is a perspective breakout view of the drive .-train of a lawn mower incorporating the invention of the application;
Figure 2 is a top view of the spring loaded dog . .
clutch shift interconnect mechanism for the transmission of the - -lawn mower of Figure l;
Figure 3 is a side view of the interconnect of Figure - . -2;
Figure 4 is a cut away cross sectional view of part of a transmission incorporating the interconnect of Figure 2; ... j.--.. .--Figure 5 is a series of representati.onal views of the spring loaded interconnect mechanism and the dog clutch of Figure 4 showing various operating positions thereof; :-: .
Figure 6 iiY a side view of the speed and direction : -operator controls of the lawn mower of Figure l; and, Figure 7'is a side view of the main operating control :~.
detailing the interconnection of the reverse interlock. : . .
l , ',, l Page #2 .-~ ~ 22~
Description Of The Drawinqs This invention relates to improved operator controls.
The in~ention will be described in its preferred embodiment of operator control for a rear engine, front control lawn mower.
Other engine and control placements could also be utilized with the invention.
The lawn mower 20 has a body 21, a transmission 22, a separate variator drive mechanism 23, and operator station controls 24 (Figure 1).
The body 21 provides a physical support and locating means for the remainder of the parts of the lawn mower 20. The particular body 21 shown is a stamped steel frameless member having integral reinforcing flanges 30 and access cutouts 31.
The flanges 30 are designed so as to strengthen the rigidity of the stamped steel sections of the body 21. The cutouts 31 are designed in order to provide either physical access to or ~ -physical space for other parts of the lawn mower 20. Other body designs with or without separate frames could also be utilized as appropriate.
The transmission 22 for the lawn mower 20 selectively interconnects the engine 35 to the ground engaging wheels 36.
The particular transmission 22 shown in the preferred embodiment is a forward--neutral--reverse shift transmission - -having a reduction gear train and differential for use with a separate variator speed mechanism 23 (later described).
~Integral speed features could be incorporated into the transmission if desired--i.e. multiple gears, integral variator, hydrostatic, etc.) The particular transmission 22 disclo~ed ha~ a slideable dog clutch 39 located on a central ¦ Dg~ ~3 ~ ~
~ ~ 20~0~
rotatable drive shaft 40 between the forward 37 and reverse 38 gears for the transmission 22 (Figure 4). These two gears 37, 38 are'in constant mesh with an input bevel gear driven by the shaft 53 for providing oppositely rotating gears on the shaft 40. The teeth 34 of the dog clutch 39 selectively engage holes 41 in either the forward 37 or reverse 38 gears in order to interconnect same to the drive shaft 40 and th.us provide for forward and reverse operations of the transmission 22. There is a gear 36 on the rotatable shaft 40 that in turn drives the reduction gear (and output axles) of the transmission 22. Note that in the particular transmission 22 disclosed, the teeth 34 of the dog clutch 39 do not retract. This particular construction allows the dog clutch 39 to be made stronger than would be possible in the same space had retractable spring loaded teeth been utilized instead. This presents problems and advantages later discussed. If desired other transmissions including those having integral variable speed mechanisms (meshing gear, hydrostatic, etc.) could be utilized with the invention.
The variator mechanism 23 is connected between the engine 35 and the transmission 22 in order to selectively ;~ ;
interconnect the same (Figure 1). In the particular embodiment -shown, the preferred variator mechanism 23 is a belt mechanism incorporating both variable speed and selective clutching attributes. This variator mechanism 23 utilizes a fixed diameter input pulley 42 journaled on the output shaft of the -engine 35. This pulley 42 is connected by a belt 44 to the variator pulley 43. This variator pulley 43 itself mounted in a fixed location to the body 21 of the lawn mower 20. This . . ,.,..
' Page #4 . , : , , .: , :. .
21)22~0~ 1 variator pulley 43 includes two variable diameter sheave~ 56, 57. The belt 44 from the engine 35 is connected to the upper sheave ~6 of the variator pulley 43. The belt 44 also is fed about the pulley 45 which is mounted to the end of a moveable arm 49. The effective length of this belt 44 is adjusted through the use of selective movement of this arm 49 (as later described). A spring 47 biases the arm 49 (and,thus the belt 44) into its high speed engaged position (as later described).
The upper sheave 56 of the variator pulley 43 is n~ <~-7 rr~)n~ w-~r ~l~a;~v~ r~-7 ~f l l~o vn~ tr r t~ v movable element 50. The movement of this element 50 alters r~lationship between the effective, diameters of the two sheaves 56, 57 of the variator pulley 43. The lower sheave 57 of the variator pulley 43 is interconnected ,to the input shaft 53 of the transmission 22 by a second belt 52 interconnecting to a large diameter pulley 54 interconnected to such input shaft 53.
A spring loaded idler mechanism 55 mounted on the pivoting arm 46 insures that this second belt 52 is under constant tension.
With this variator mechanism, movement of the arm 49--i.e. movable pulley 45--directly alters the relative speed of the input shaft 53 of the transmission 22 in respect to the speed of the pulley 42 on the engine 35 by altering the ratio ,-of the diameters of the upper sheave 56 to lower sheave 57,of the variator pulley 43. The actual movement of the arm 49 is accomplished through the use of a rod 48 which interconnects , directly to the arm 67 off of the pedal 60 at the operator -station controls 24. Upon forward positioning of the pedal 60, "~
the belt 44 has no tension such that the pulley 42 of the ¦ engine 35 rotates freely of the variator mechanism 23--i.e. the ,' age S
. 1 ~, J --2022~0~
¦ drive is declutched. Upon movement of the pedal 60 rearward the rod 48 also moves rearward. The spring 47 facilitates this movement. The rearward movement of the rod 48 in turn engages and then begins to shorten the effective length of the belt 44 between the engine 35 and variator pulley 43. This first engages the drive between engine and transmission--i.e.
clutches the lawn mower drive. Subsequent move~ent of the pedal 60 further tightens the belt 44. This causes the movable element 50 of the variator pulley 43 to move downwards. This in turn alters the diameters of the sheaves 56, 57 and thus lengthens the effective length of the second belt 52 between the variator pulley 43 and the input shaft 53 of the transmission 22. In combination this action reduces the ~ -relative ratio of speed between the engine 35 and the input -shaft 53 of the transmission 22--i.e. increases the mowers -speed of travel. Upon movement of the pedal 60 forward, the -rod 48 moves forward (and thus the movable pulley 45 inwards) in order to lengthen the length of the belt 44. This in turn increases the size of the top sheave 56 and reduces the size of -the bottom sheave 57 of the variator pulley 43 in order to increase the ratio of speed of the transmission pulley 54 in respect to the engine pulley 40--i.e. reduces the mowers speed --of travel. Eventually the belt 44 is relieved of tension and -the drive between engine and transmission is again ~ --disengaged--i.e. the lawn mower drive is declutched. -The forward/reverse movement of the rod 48 is under the operator's control at the operator station 24. The operator station controls 24 include a main foot pedal 60, a ¦ Page :6 , ,, ~ , .... . . . . . . .. . .. .. . . . .
1 202~0~
¦ lever 61, a power takeoff lever 62, and a parking brake 63 (Figures 1, 6 and 7).
The foot pedal 60 is the main operational control for the lawn mower 20. This foot pedal 60 controls the speed of the lawn mower 20 including braking functions The foot pedal 60 shown accomplishes this operational control through the use of a rotating rod 64 located underneath the body 21 of the mower. The speed rod 48 is attached to a hole in the extension arm or bracket 65 of the rotating rod 61 such any rotary movement of the foot pedal 60 is transferred directly into a corresponding forwardtreverse axial movement of the rod 48 (from the default spring loaded rqarward position of the rod 48 application of the foot pedal 60 pulls such rod 48 forward). A
brake rod 66 is interconnected into a slot 67 in the same extension 65 of the foot pedal 60 such that on the forward positioning of the foot pedal 60, the brake rod 66 is pulled forward to apply the brake. The slot 67 which interconnects the brake rod 66 to the part 65 of the rotating rod 64 thus - :
allows for a lost motion interconnection such that the brake is disconnected from the foot pedal 60 for most of the travel ~-thereof. A spring 69 located between the brake rod 66 and the actual braking mechanism 68 on the transmission 22 allows for a mechanical interconnection therebetween such that there is a modicum of over travel on the foot pedal 60 after the brakes are applied. This over travel allows the bottom section 70 of the parking brake rod 63 to be selectively engaged with a hook 71 extending off of, another extension 72 of the rotating rod 64 to hold the foot pedal 60 forward and the brake rod 66 in an engaged parking position upon the downward positioning of the Page 7 ¦
."~.' "
2022~0~ 1 parking brake rod 63. Note that except for shifting the transmission into reverse, the foot pedal 60 controls the directional operation of the lawn mower 20--i.e. clutching, speed of travel, and braking functions. (The preferred embodiment has only one reverse speed. In other embodiments multiple reverse speeds could be provided if desired.) The speed of forward travel and the.reverse shifting for the preferred transmission 22 is controlled by the reverse 1-shift--forward speed preset shifter control 85. This control -85 is rotatively connected to the body 21 of the lawn mower.
The control 85 is mechanically interconnected to the forward speed rotating rod 64 ~and thus the foot pedal 60) via a rod 80 interconnecting a slot 81 in the control 85 with a hole 82 in the other extension 72 of the speed rotating rod 64. The positioning of the preset control 85 is thus able to limit the rearward motion of the rotating rod 64 after a certain predetermined point. The predetermined point is set by the preset lever 87. This forward speed preset lever 87 is ~-rotatively mounted to the body 21 of the lawn mower neighboring the lever 61 of the control 85. In use the operator determines ~-initially what maximum speed he desires to operate the lawn - :
mower. The operator then sets the preset lever 87 into the appropriate one of the slots 86 in the body of the lawn ~ower immediately adjacent to the preset lever 87. The position of this preset lever 87 determines the maximum angular rotation of the control 85 (and thus the rotating rod 64) by allowing such control 85 to move no further forward than the physical positioning of the lever 87. In the embodiment disclosed, the I ; ~: ~
Page #8 , -. ' , `- - 2022~0~ 1 more forward the slot 86 for the lever 87, the higher the maximum preset forward speed of the lawn mower.
' In use the operator begins with the foot pedal 60 in a forward braked position. Upon release of the foot pedal, the rotating rod 64 and the extension 65 of the pedal control rod move backward. This releases the brakes via movement of the brake rod 66. The rod 80 (interconnecting with the front of the hole 82 of the other extension 72) also begins to move the reverse shift/forward speed preset control 85 forward.
Eventually the lever 61 of the control 85 will contact the speed preset lever 87 (previously positioned by the operator).
At this point the control 85 will not move further. When the hole 82 in the extension 72 contacts the rod 80, this rod 80 then cannot move backwards any more and the movement of the rotating rod 64 is ceased. This causes the lawn mower to proceed in the speed set by the forward speed preset lever 87. -If the operator wants to go faster than this speed, the operator pushes in the foot pedal 60 slightly to release the tension between the lever 61 of the control 85 and preset lever 87 and moves the preset lever 87 to a more forward slot 86.
Upon release of the foot pedal 60, the lawn mower will proceed at the higher rate of speed. Similarly the speed can be reduced by moving the speed preset lever 87 backward into a more rearward slot 86.
In order to place the lawn mower into reverse, the lever 61 of the control 85 is pulled backwards. This backward ;
motion o the control 85 moves a bearing 89 in a slot 88 to cau~e movement of the lever 90 from its normal forward gear ¦ po~ition to a rearward reverse gear position. This causes the ¦ Page #9 202~50~ 1 forward--neutral--reverse lever 91 of the transmission 22 to switch between its forward and reverse conditions (by a shift mechanism later described). Note that there is a notch 93 that interconnects with the power takeoff lever 62 in order to prevent the movement of the control 85 into a reverse position while the power takeoff 62 is engaged (Figure 7). This reverse interlock feature is accomplished by having a rod 94 extend from an extending portion 95 of the power takeoff lever upwards adjacent to the notch 93 on the control 85 such that when the po~er takeoff lever 62 is in its rearw~rd n~n-o~ od p~tl~n, ~- --there is a clearance between the end 96 of the rod 94 and the notch 93. When these two parts are in this orientation, the lever 61 can be moved backwards into its reverse gear selection -position without opposition~ However upon movement of the power takeoff lever 62 forwards into an engaged condition (as shown in Figure 7), the end 96 of the rod 94 is moved upwards such that such end 96 is within the arc traced by the notch 93.
Thereafter upon attempted motion of the control 85 backwards to engage reverse gear, the notch 93 will engage the end 96 of the -rod 94 prior to the transmission 22 being switched into its reverse condition. This interconnection prevents the engagement of the reverse condition of the transmission 22 while the power takeoff lever 62 is engaged. The net effect is -that an operator is unable to operate the machine in reverse without first disengaging the power takeoff lever 62.
The positioning of the forward speed preset lever 85 :
does not have any effect on the reverse speed of the lawn mower 20 which is set at a single 8peed in this preferred embodiment I . , ',' ,~''' I . ' ~:' ¦ Page #10 , . .:,, . , -.. . .. . . .
~- ~ 202~
(in other embodiments multiple speeds could be provided if desired with or without usage of the control 85).
The forward--neutral--reverse lever 90 is interconnected with the forward--neutral--reverse lever 91 of the transmission 22 through a lost motion spring loaded shift mechanism 100 (Figures 2-5). This shift mechanism 100 is designed to allow the shifting of the transmission 22, which has a fixed teeth dog clutch, between forward gear and reverse gear drive states without first aligning the teeth 34 of the dog with the notches 41 in the gears.
The shift mechanism 100 begins with a rod 101 that is connected between the lower end of the forward--neutral--reverse léver 90 such that any rotary movement of the lever 90 is transferred into axial movement of the rod 101. The other end section of the rod 101 is in turn connected at the rear of the lawn mower to a pivoting arm 102 which is pivotally bolted to a flange 103 extending off of the transmission 22. The bolts 112 to connect this flange 103 to -the transmission 22 are the same bolts used for as the brake -mechanism 68. This reduces the number of parts for the shift - -mechanism 100 as well as allowing it to be incorporated into -the transmission 22 without need for special mounting holes, -etc. (This allows an existing transmission to be utilized.) The direct connection of the flange 103 to the casting of the ~-transmission 22 insures that there is a minimal dimensional tolerance problem for the mechanism 100. The arm 102 in turn pivots around a bolt 104 such that forward and backward axial movement of the rod 101 is transferred into side to side movement of a ~mall tab 106 which extends downwardly off of the ~dge~
,, , , . , ,,,, .,~"", ", ., , " . . " . ", " , ~ , .
. . . .. . . . ..
- 202250~ 1 l arm 102. The tab 106 in turn has a hole 107 in the center ¦ thereof through which a further rod 108 or actuation piece extends. One end 109 of this rod 108 is pinned to the forward--neutral--reverse lever 91 on the transmission 22 for movement therewith. The other end 110 of the rod 108 has a nut 111 on it. The flange 106 is located on the rod between the two ends thereof. There are two springs 114, 115 which extend about the rod 108 on either side of the flange 106 thereof.
In a neutral position the flange 106 is located substantially in the middle of the rod 108 between the two ends 109 and 110 (see position A of Figure 5). (The fact that the end 109 of the rod 108 is adjustable through the nut 111 allows this neutral position to be preset during initial manufacture and subsequently). Upon movement of the rod 101 into a forward position, the flange 106 is moved to the right against the pressure of the spring 115 ~see position B of Figure S). At :
this time the dog 39 in the transmission is urged against the forward gear 37. If the teeth 34 of the dog clutch 39 are not ~
perfectly matched with the hole 41 in the forward gear 37, the ;-dog 39 will not drivingly engage the gear 37. The spring 115, however, biases the teeth 34 into engagement with the gear 37. :' Upon release of the foot pedal 60, the dog 39 begins to rotate -and with rotation comes the alignment of the teeth 34 with the hole 41 in the forward gear 37. At this point the teeth 34 engage the hole 41 so as to drivingly interconnect the dog 39 with the gear 37 (position C of Figure 5). This is the forward condition of the transmission. Upon shifting of the transmission back into a neutral condition (position D of ¦ Figure 5), the teeth 34 will normally disengage from the gear age tl2 ~ '- ~ 2~Z2!j~
37. Under certain circumstances, however, this may not occur.
Since this shifting condition also produces the neutral posi*~on o~ the main drive clutch for the entire unit, the fact that the dog 39 might not be disengaged from a gear is of no importance. However upon shifting of the transmission into reverse (position E of Figure S), the spring 114 will be physically collapsed into a solid mass such th~t there will be a solid interconnection between the flange 106 and the end 109 of the bolt 108. At this time any further movement of the flange will physically move the dog 39 out of engagement with the forward gear 37 and move its teeth 34 into spring loading biased position in respect to the reverse gear 38 ~position F
of Figure S--this is equivalent to position B in respect to a ~-forward condition. If the dog 39 is already disengaged from the forward gear 37, the movement will move the dog 39 into the same spring loaded biased position in respect to the reverse gear 38). At this point release of the clutch will again cause the dog 39 to begin rotating to align the teeth 34 with the - -hole 41 (if not already aligned) and thus drivingly engage the dog 39 with the reverse gear 38. Note that in all of this shifting it is not necessary for the dog 39 to be in driving engagement with either the forward 37 or the reverse 38 gear in order for the control 85 (and interconnecting parts including the flange 106) to be positioned in a forward or reverse position. This allows shifting between forward, neutral and reverse at any time. Note also that due to the physical size of the compacted springs 114, 115, it is impossible for the flange 106 to be shifted into either a forward or reverse condition while the oppo~ite gear 37, 38 is still engaged with .
Page #13 ~ ~_ ` 202250~ 1 the dog 39. This mechanism thus provides for forward--neutral--reverse fixed position shifting of a transmission in a non-synchronized dog clutch type mechanism.
Although the invention has been described in its preferred form with n cortnill ~e~ree ~f p.~tic~ r11y, be understood that numerous changes can be made without deviating from the invention as hereinafter claimed.
Page ~14
Claims (17)
- Claim 1. A mechanism for connecting a shifter control to a transmission having a forward and reverse gearing selectable via movement of a lever, the mechanism comprising an actuation piece, said piece having two ends, a flange, said flange being located substantially at the midpoint of said piece between said two ends thereof, a first spring, said first spring extending between said flange and one of said two ends, a second spring, said second spring extending between said flange and the other of said two ends, means to connect one of said piece or said flange to the lever and means to connect the other of said piece or said flange to the shifter such that the forward and reverse positioning of the shifter is transferred to the lever by said first and second springs.
- Claim 2. The mechanism of Claim 1 wherein the forward and reverse gearing is selectable by movement of a shifter dog having fixed teeth engaging fixed teeth on the gears.
- Claim 3. The mechanism of Claim 1 characterized in that said first spring and said second spring have collapsed lengths respectively and said flange and said two ends have to move more than said lengths to alter the forward and reverse gearing condition of the transmission.
- Claim 4. The mechanism of Claim 1 characterized in that said piece is solidly connected to the lever.
- Claim 5. The mechanism of Claim 4 characterized in that said piece is solidly connected to the lever at an end of said piece.
Page #15 - Claim 6. The mechanism of Claim 1 characterized in that said flange has a hole and said piece is a rod extending through said hole.
- Claim 7. The mechanism of Claim 1 wherein the shifter moves perpendicularly in respect to the lever and characterized in that the shifter is connected to said flange through an arm, said arm being pivotally mounted to the transmission, and said arm transferring the movement of the shifter perpendicularly to the lever.
- Claim 8. A mechanism for connecting a shifter to a transmission having a forward and reverse gearing selectable via movement of a shift dog having fixed teeth engaging a forward or a reverse gear having fixed teeth, the shift dog selectably shifted via a lever, the mechanism comprising an actuation rod, said rod having two ends, a flange, said flange having a hole, said flange being located substantially at the midpoint of said rod between said two ends thereof with said rod lead through said hole in said flange, a first spring, said first spring extending between said flange and one of said two ends of said rod, a second spring, said second spring extending between said flange and the other of said two ends of said rod, means to connect said rod to the lever and means to connect said flange to the shifter such that the forward and reverse positioning of the shifter is transferred to the lever by said first and second springs to allow forward and reverse positioning of the lever irregardless of the engagement of the shift dog to the forward or reverse gear respectively.
- Claim 9. The mechanism of Claim 8 characterized in that said first spring and said second spring have collapsed Page #16 lengths respectively and said flange and said two ends have to move more than said lengths to alter the forward and reverse gearing condition of the transmission.
- Claim 10. The mechanism of Claim 8 characterized in that said piece is solidly connected to the lever.
- Claim 11. The mechanism of Claim 10 characterized in that said piece is solidly connected to the lever at an end of said piece.
- Claim 12. The mechanism of Claim 8 wherein the shifter moves perpendicularly in respect to the lever and characterized in that the shifter is connected to said flange through an arm, said arm being pivotally mounted to the transmission, and said arm transferring the movement of the shifter perpendicularly to the lever.
- Claim 13. A mechanism for connecting a shifter to a transmission having a forward and reverse gearing selectable via movement of a shift dog having fixed teeth engaging a forward or reverse gear having fixed teeth, the shift dog selectably shifted via a lever, the transmission having a casing, the mechanism comprising an actuation rod, said rod having two ends, one end of said rod being connected to the lever, a pivot arm, said pivot arm being rotatively mounted to the casing of the transmission about a pivot point, said pivot arm having a flange spaced from said pivot point, said flange having a hole, said flange being located at the midpoint of said rod between said two ends thereof with said rod extending through said hole in said flange, a first spring, said first spring extending between said flange and one of said two ends of said rod, a second spring, said second spring extending Page #17 between said flange and the other of said two ends of said rod, and means to connect the shifter to said pivot arm at a point spaced from said pivot point such that the selective movement of the shifter moves said flange a sufficient distance engage the shift dog with the desired gear.
- Claim 14. The mechanism of Claim 13 characterized in that said flange has to move between a first position engaging the shift dog with a first gear and a second position engaging the shift dog with a second gear, said first spring having a solid collapsed length, said second spring having a solid collapsed length and said solid collapsed length of said first spring and said second spring being sufficient to move said flange out of one of said first or second position before said flange is in the other of said first or second position.
- Claim 15. In a transmission having a forward and reverse control rotatably mounted to a body of a lawn mower, the control interconnected to the forward and reverse shifter of a transmission, and a power takeoff lever movable between engaged and disengaged positions, a reverse power takeoff inhibition mechanism comprising a notch, said notch being in the forward and reverse control, a rod, said rod having two ends, one end of said rod being connected to the power takeoff lever, a slot, said slot being in the body of the lawn mower neighboring the forward and reverse control, the other end of said rod being located in said slot and said other end of said rod engaging said notch in the forward and reverse control so as to prevent this control from moving the lever into a reverse condition when the power takeoff lever is in an engaged position.
- Claim 16. In a lawn mower having a body, a variable speed mechanism, a transmission with forward and reverse gearing, and a brake, an improved control comprising a foot pedal, said foot pedal being rotatively mounted to the body of the lawn mower, a bracket means, said bracket means being non-rotatively connected to said foot pedal, a first rod, said first rod directly connecting said bracket means to the variable speed mechanism, a slot, said slot being in said bracket means, a second rod, said second rod connecting said slot in said bracket means to the brake to provide a lost motion interconnection therebetween upon engagement of said second rod with an end of said slot, a second slot, said second slot being in said bracket means, a preset speed control lever, said control lever being selectably movably mounted to the body of the lawn mower, a third rod, said third rod connecting said control lever to said second slot in said bracket means to provide for a limit stop to prevent rotation of said foot pedal after engagement of said third rod with an end of said second slot, and means to connect said control lever to the transmission for selection of forward and reverse gearing.
- Claim 17. The control of Claim 16 characterized in that said second rod includes a spring means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54101390A | 1990-06-20 | 1990-06-20 | |
| US541,013 | 1990-06-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2022504A1 true CA2022504A1 (en) | 1991-12-21 |
Family
ID=24157846
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2022504 Abandoned CA2022504A1 (en) | 1990-06-20 | 1990-08-01 | Mower variator control mechanism |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2022504A1 (en) |
-
1990
- 1990-08-01 CA CA 2022504 patent/CA2022504A1/en not_active Abandoned
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6250414B1 (en) | Working vehicle | |
| CA2098892C (en) | Operator control for lawn and garden vehicles | |
| US4835949A (en) | Operator presence control for self-propelled implements | |
| US4689939A (en) | Operator presence control for self-propelled implements | |
| US20070240533A1 (en) | Speed change operating structure for hydrostatic stepless speed-changing apparatus of work vehicle | |
| CA2022504A1 (en) | Mower variator control mechanism | |
| CA2008712C (en) | Transmission control for self-propelled implement (13540-can) | |
| JP4474793B2 (en) | Traveling device | |
| JP2002193136A (en) | Traveling device | |
| JP4297589B2 (en) | Ride type rice transplanter | |
| JP3399026B2 (en) | Transmission operating device for traveling transmission | |
| JPS5856971A (en) | Very wet ground turning equipment | |
| JPH0774009B2 (en) | Work vehicle | |
| JPH0680088A (en) | Steering clutch for combine, etc. | |
| JP3443458B2 (en) | Work vehicle power take-out device | |
| JP3002440B2 (en) | Combine hydraulic unit | |
| JPS6316311B2 (en) | ||
| JP4600639B2 (en) | Traveling device | |
| JPH0745154Y2 (en) | Operation device in work vehicle | |
| JPS6251764B2 (en) | ||
| JPH0711007Y2 (en) | Hydraulic circuit structure of work vehicle | |
| JP3179011B2 (en) | Hydraulic valve neutral position return mechanism | |
| JP4141312B2 (en) | Ride type rice transplanter | |
| JP3458410B2 (en) | Transmission operating device for traveling transmission | |
| JPH061858Y2 (en) | Gear shift operation mechanism in work vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |