The present disclosure relates to a garden tool, such as a robotic lawn mower, having a driven implement such as a blade for cutting grass or other plants.
In one aspect, the disclosure provides a robotic garden tool. The robotic garden tool includes a deck, an implement movably coupled to the deck, a motor configured to drive the implement, and a height adjustment mechanism configured to control the movement of the implement with respect to the deck. The height adjustment mechanism includes an interface of meshing gear teeth.
Alternatively or additionally, in any combination: the interface of meshing gear teeth includes a first set of gear teeth and a second set of gear teeth, wherein the first set of gear teeth is configured to mesh with the second set of gear teeth; the first set of gear teeth is configured to be manually actuated to effectuate movement of the second set of gear teeth; the second set of gear teeth is configured to be driven by a servomotor; the height adjustment mechanism further includes a manual actuator configured to move in response to manual actuation by an operator, wherein the implement is configured to move with respect to the deck in response to the manual actuation of the manual actuator; the interface of meshing gear teeth includes a spiral rack and a bevel gear; the spiral rack defines a central axis and is configured to rotate about the central axis; the bevel gear is biased into engagement with the spiral rack and configured to move at least axially with respect to the central axis; the implement is configured to move at least axially in response to axial movement of the bevel gear; the height adjustment mechanism further includes a servomotor configured to drive the bevel gear or the spiral rack; the interface of meshing gear teeth includes a linear rack and a circular gear; the circular gear is configured to be manually actuated to effectuate movement of the linear rack; the height adjustment mechanism further includes a servomotor configured to drive the linear rack or the circular gear; rotation of at least a portion of the interface about a central axis causes the implement to move at least 0.75 inches per 90 degrees of rotation; the interface may include a manual actuator.
In another aspect, the disclosure provides a cutting module for a robotic garden tool. The cutting module includes a motor configured to drive an implement, and a height adjustment mechanism configured to move the implement independently from the driving of the implement. The height adjustment mechanism includes an interface of meshing gear teeth.
Alternatively or additionally, in any combination: the interface of meshing gear teeth includes a first set of gear teeth and a second set of gear teeth, wherein the first set of gear teeth is configured to mesh with the second set of gear teeth; the first set of gear teeth is configured to be manually actuated to effectuate movement of the second set of gear teeth; the second set of gear teeth is configured to be driven by a servomotor; the interface of meshing gear teeth includes a spiral rack and bevel gear interface or a linear rack and circular gear interface.
In another aspect, the disclosure provides a robotic lawn mower. The robotic lawn mower includes a deck, a blade configured for movement with respect to the deck, and a motor configured to rotate the blade about an axis of rotation. The rotation is independent from the movement with respect to the deck. The robotic lawn mower also includes a height adjustment mechanism configured to control the movement of the blade with respect to the deck. The height adjustment mechanism includes an interface of meshing gears.
Alternatively or additionally, in any combination: the interface of meshing gears includes a first set of gear teeth and a second set of gear teeth, wherein the first set of gear teeth is configured to mesh with the second set of gear teeth; the first set of gear teeth is configured to be manually actuated to effectuate movement of the second set of gear teeth; the second set of gear teeth is configured to be driven by a servomotor; the height adjustment mechanism further includes a manual actuator configured to move in response to manual actuation by an operator, wherein the blade is configured to move with respect to the deck in response to the manual actuation of the manual actuator; the interface of meshing gears includes a spiral rack and a bevel gear; the spiral rack defines a central axis and is configured to rotate about the central axis; the bevel gear is biased into engagement with the spiral rack and configured to move at least axially with respect to the central axis; the blade is configured to move at least axially in response to axial movement of the bevel gear; the height adjustment mechanism further includes a servomotor configured to drive the bevel gear or the spiral rack; the interface of meshing gears includes a linear rack and a circular gear; the circular gear is configured to be manually actuated to effectuate movement of the linear rack; the height adjustment mechanism further includes a servomotor configured to drive the linear rack or the circular gear; rotation of at least a portion of the interface about a central axis causes the implement to move at least 0.75 inches per 90 degrees of rotation; the interface may include a manual actuator.
In yet another aspect, the disclosure provides a robotic garden tool. The robotic garden tool includes a deck, an implement coupled to the deck, a motor configured to drive the implement, and a height adjustment mechanism configured to control movement of the implement with respect to the deck independently from the driving of the implement. The height adjustment mechanism includes nesting ramps.
Alternatively or additionally, in any combination: the nesting ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement with respect to the deck, and the extended position corresponds with a second position of the implement with respect to the deck, wherein the first position is different from the second position; the motor is configured to drive the implement when the implement is in the first position and when the implement is in the second position; the nesting ramps include at least a first ramp and a second ramp, the first ramp including a first helical surface and the second ramp including a second helical surface; the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement with respect to the deck, and the extended position corresponds with a second position of the implement with respect to the deck, wherein the first position is different from the second position; each of the first and second ramps is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is smaller than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp with respect to the second ramp; the nesting ramps include at least a first ramp and a second ramp, the first and second ramps being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is smaller than a second radius defined from the axis to the second ramp to allow nesting of the first ramp into the second ramp; the first ramp is configured to nest in the second ramp in a retracted position; the first and second ramps are movable with respect to each other between a retracted position and an extended position.
In still another aspect, the disclosure provides a cutting module for a robotic garden tool. The cutting module includes a motor configured to drive an implement, and a height adjustment mechanism configured to move the implement independently from the driving of the implement. The height adjustment mechanism including nesting ramps.
Alternatively or additionally, in any combination: the nesting ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement, and the extended position corresponds with a second position of the implement, wherein the first position is different from the second position; the motor is configured to drive the implement when the implement is in the first position and when the implement is in the second position; the nesting ramps include at least a first ramp and a second ramp, the first ramp having a first helical surface and the second ramp having a second helical surface; the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement, and the extended position corresponds with a second position of the implement, wherein the first position is different from the second position; each of the first and second ramps is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is smaller than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp with respect to the second ramp; the nesting ramps include at least a first ramp and a second ramp, the first and second ramps being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is smaller than a second radius defined from the axis to the second ramp to allow nesting of the first ramp with respect to the second ramp; the first ramp is configured to nest in the second ramp in a retracted position; the first and second ramps are movable with respect to each other between a retracted position and an extended position.
In another aspect still, the disclosure provides a robotic lawn mower. The robotic lawn mower includes a deck, a blade configured for movement with respect to the deck, and a motor configured to rotate the blade about an axis of rotation. The rotation is independent from the movement with respect to the deck. The robotic lawn mower further includes a height adjustment mechanism configured to control the movement of the blade with respect to the deck. The height adjustment mechanism including nesting ramps.
Alternatively or additionally, in any combination: the nesting ramps include at least a first ramp and a second ramp, wherein each of the first and second ramps is rotatable about an axis, wherein the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the blade, and the extended position corresponds with a second position of the blade, wherein the first position is different from the second position; the nesting ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the blade with respect to the deck, and the extended position corresponds with a second position of the blade with respect to the deck, wherein the first position is different from the second position; the motor is configured to drive the blade when the blade is in the first position and when the blade is in the second position; the nesting ramps include at least a first ramp and a second ramp, the first ramp including a first helical surface and the second ramp including a second helical surface; the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the blade with respect to the deck, and the extended position corresponds with a second position of the blade with respect to the deck, wherein the first position is different from the second position; each of the first and second ramps is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is smaller than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp with respect to the second ramp; the nesting ramps include at least a first ramp and a second ramp, the first and second ramps being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is smaller than a second radius defined from the axis to the second ramp to allow nesting of the first ramp into the second ramp; the first ramp is configured to nest in the second ramp in a retracted position; the first and second ramps are movable with respect to each other between a retracted position and an extended position.
Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings.
Before any implementations of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other implementations and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The terms “approximately”, “about”, “generally”, “substantially”, and the like should be understood to mean within standard tolerances, as would be understood by one of ordinary skill in the art, unless other definitions are provided for certain contexts below. The term “helical surface” is defined herein as a surface that includes a helical curve. A “helical curve” is a curve on a conical or cylindrical surface (which may be an imaginary conical or cylindrical surface for purposes of definition only) other than a two-dimensional arc. Thus, to be “helical” means to include a helical curve on a surface.
For example, as illustrated in
With reference to
The lawn mower 12 also includes a plurality of wheels 18 (
The lawn mower 12 includes a power source 24 (
With reference to
The lawn mower 12 includes a cutting module 30 (
The motor 36 includes a rotatable drive shaft 38 operably coupled to the blade module 28 (or any other implement in accordance with any implementation of the disclosure). In the illustrated implementation, the drive shaft 38 is disposed coaxially with the axis of rotation A. In other implementations, the drive shaft 38 may be disposed parallel with (e.g., offset from) or transverse to the axis of rotation A. The axis of rotation A defines an axial direction B. The axial direction B is typically a vertical direction with respect to the support surface on which the lawn mower 12 rides, e.g., up and down with respect to gravity, when the lawn mower 12 is in use. However, in certain implementations, the axis of rotation A (and thus the axial direction B) may be tilted relative to the vertical direction, for example by 1 to 10 degrees, preferably by 3 to 8 degrees, and more preferably by 5 to 6 degrees. In certain implementations, the axis of rotation A may be tilted forward in the travelling direction relative to the vertical direction.
The blade module 28 (
The cutting module 30 also includes a height adjustment mechanism 90 (
With reference to the implementation of
In the illustrated implementation, the spiral rack 102 includes a helical surface 109 extending 360 degrees about the central axis C. The rack teeth 108 protrude from the helical surface 109. In other implementations, the helical surface 109 may have other configurations. For example, the helical surface 109 may extend less than 360 degrees about the central axis C to increase the pitch. As another example, the helical surface 109 may be broken into two separate helical surfaces extending 180 degrees each about the central axis C, or three separate helical surfaces extending 120 degrees each about the central axis C, etc., and a corresponding number of bevel gears 104 may be employed. In the illustrated implementation, the helical surface 109 has a pitch angle of about 114.3 degrees per inch (with “about” meaning +/−10 degrees per inch) (the pitch angle is about 4.5 degrees per mm). In some implementations, the pitch angle may be between about 50.8 degrees per inch and about 152.4 degrees per inch (between about 2 degrees per mm and about 6 degrees per mm). The helical surface 109 has a radius R (from the central axis C as shown in
With reference to
The height adjustment mechanism 90 includes a motor mount 114 configured to support the motor 36 in a generally fixed relation thereto, which may include a degree of movement or damping to adapt to vibrations, external force, etc., or may be rigidly fixed. The motor mount 114 is axially slidable, in the direction of the central axis C, with respect to the cutting module mount 32. The motor mount 114 may be fixed against rotational movement with respect to the deck 14 such that the motor mount 114 is configured to translate in the direction of the axis C without rotation with respect to the deck 14. In the illustrated implementation, the motor mount 114 includes one or more lobes 118 that guide the motor mount 114 to move in the direction of the axis C along tracks 120 in the cutting module mount 32. The motor mount 114 is movable between the raised position in which the blade 34 is fully raised and the lowered position (
In the illustrated implementation, the bevel gear is rotatably coupled to the motor mount 114 by way of the bevel shaft 107. The manual actuator 92 is operatively coupled to the spiral rack 102. As illustrated, the manual actuator 92 is fixed to the spiral rack 102, such that the manual actuator 92 and the spiral rack 102 rotate together as one unit. However, in other implementations, an intermediate transmission may be disposed between the manual actuator 92 and the spiral rack 102.
Thus, in the illustrated implementation, manual rotation of the manual actuator 92 causes rotation of the spiral rack 102. The rack teeth 108 are configured to mesh with the bevel teeth 106. Rotation of the spiral rack 102 thereby causes the bevel gear 104 to rotate about the gear shaft axis D. The bevel gear 104, being biased upwards away from the support surface, rises and lowers in the direction of the central axis C to follow the spiral rack 102 as the spiral rack 102 rotates about the central axis C. The motor mount 114 rises and lowers in the direction of the central axis C with the bevel gear 104, as does anything fixed with the motor mount 114, such as any combination of one or more of the motor 36, the blade 34, the blade holder 46, etc.
In other implementations, the bevel gear 104 may be driven by a servomotor 122, which is illustrated schematically in
The height adjustment mechanism 90 also includes one or more biasing members 116, such as coil springs (as illustrated), one or more leaf springs, one or more cup springs, any other type of spring or resilient member, or the like, for biasing the motor mount 114 upwards in the direction of the central axis C (away from the support surface). The one or more biasing members 116 restore the motor mount 114 to its highest position (the raised position). Specifically, each of the one or more biasing members 116 is disposed between the cutting module mount 32 and the motor mount 114. Even more specifically, each of the one or more biasing members 116 is disposed between a respective one of the lobes 118 and the cutting module mount, and each of the one or more biasing members 116 is received in the respective track 120. In the illustrated implementation, the one or more biasing members 116 are each in direct engagement with the cutting module mount 32 and the motor mount 114; however, indirect engagement may be employed in other implementations. The one or more biasing members 116 allow the cutting module 30 to float with respect to the deck 14, and may therefore allow for movement of the cutting module 30 in more than just the direction of the central axis C.
With reference to
The cutting module 30 also includes a guard 40 (
The cutting module 30 is modular and can be removed from the lawn mower 12 as a unit and replaced as a unit.
In some implementations, the circular gear 134 may be driven by a servomotor 142, which is illustrated schematically in
In operation, blade height adjustment may be achieved manually by an operator or electronically by way of the servomotor 122, 142. For manual adjustment, the operator engages the grip surface 94 of the manual actuator 92 and moves the manual actuator 92 (e.g., rotates the manual actuator 92 about the central axis C in the illustrated implementation). At predefined angular intervals, the operator may hear and/or feel feedback from the manual actuator 92. For each angular interval of rotation of 36 degrees, the blade height changes by about 0.314 inches (8 mm) (or more in some implementations). The blade height changes by at least 1.5 inches (38 mm) or more in response to the manual actuator 92 being rotated 180 degrees. The operator rotates the manual actuator 92 in a first direction (e.g., clockwise) to lower the blade 34 (or other implement) and in a second direction (e.g., counterclockwise) to raise the blade 34 (or other implement). The second direction is opposite the first direction. The biasing members 116 provide a force to return the blade 34 towards the raised position when the manual actuator 92 is rotated in the second direction.
Although the disclosure has been described in detail with reference to preferred implementations, variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described.
Thus, the disclosure provides, among other things, a garden tool 12, such as an autonomous lawn mower, with blade height adjustment.
In the illustrated implementation, the blade 34 is movable about 1.57 inches (40 mm) in the axial direction of the axis C between a raised position (
The height adjustment mechanism 290 also includes an interface 300 with nesting ramps 302 (which may also be referred to as nesting telescoping ramps 302, or telescoping ramps 302, herein). The manual actuator 292 is operably coupled to the nesting ramps 302. In the illustrated implementation, the manual actuator 292 is rotatable about the axis C, which is coincident with the axis of rotation A. Thus, in the illustrated implementation the axis C also defines the axial direction B. However, in other implementations, the axis C and the axis of rotation A need not be coincident and may be offset (parallel), or transverse, to each other. The nesting ramps 302 may be described below with respect to an axial direction, which refers primarily to the direction of the axis C, but may also refer to the axial direction B when the axial direction B is the same as the axial direction of the axis C.
The nesting ramps 302 are movable with respect to each other between a retracted position (illustrated in
The nesting ramps 302 include at least a first ramp 304 and a second ramp 306. Any number of two or more nesting ramps 302 may be employed. In the illustrated implementation, the nesting ramps 302 include the first ramp 304, the second ramp 306, a third ramp 308, a fourth ramp 310, and a fifth ramp 312. The manual actuator 292 is operatively coupled to the first ramp 304 such that rotation of the manual actuator 292 about the axis C causes rotation of the first ramp 304 about the axis C. The manual actuator 292 is coupled directly to the first ramp 304; however, in other implementations, the manual actuator 292 may be coupled indirectly to the first ramp 304, or may be coupled directly or indirectly to any of the other nesting ramps 302.
The first ramp 304 may be mounted with respect to the deck 14 for rotation about the axis C and is fixed with respect to the deck 14 in the axial direction of the axis C. In some implementations, the manual actuator 292 may be mounted with respect to the deck 14 for rotation about the axis C and is fixed with respect to the deck in the axial direction of the axis C; in turn, the first ramp 304 may be mounted fixedly to the manual actuator 292 for movement therewith.
With reference to
The first ramp 304 also includes a follower 320 projecting from the outer cylindrical surface 318 and having a follower surface 322 that is offset from the helical projection 316, e.g., spaced from the helical projection 316 in the axial direction of the axis C. The follower surface 322 may be helical and may have the same pitch as the helical projection 316 described above. The follower 320 also includes a deployment stop surface 324 and a retraction stop surface 326. A normal to the deployment stop surface 324 projects in a first direction 328 of rotation of the nesting ramps 302 about the axis C, and a normal to the retraction stop surface 326 projects in a second direction 330 of rotation of the nesting ramps 302 about the axis C. The second direction 330 of rotation is opposite the first direction 328 of rotation.
With continued reference to
The second ramp 306 also includes a follower 340 projecting from the outer cylindrical surface 338 and having a follower surface 342 that is offset from the helical projection 336, e.g., spaced from the helical projection 336 in the axial direction of the axis C. The follower surface 342 may be helical and may have the same pitch as the helical projection 316 described above. The follower 340 also includes a deployment stop surface 344 and a retraction stop surface 346. A normal to the deployment stop surface 344 projects in the first direction 328 of rotation about the axis C, and a normal to the retraction stop surface 146 projects in the second direction 330 of rotation about the axis C.
The third ramp 308, the fourth ramp 310, and the fifth ramp 312 each have all the same features as the second ramp 306 described above and shown in
Specifically, as illustrated in
The inner cylindrical surface 335″ of the fourth ramp 310 is disposed approximately at the radial distance R3, and the outer cylindrical surface 338″ of the fourth ramp 310 is disposed approximately at the radial distance R4. The helical track 348″, the deployment stop 350″, and the retraction stop 352″ of the fourth ramp 310 extend radially between the inner and outer cylindrical surfaces 335″, 338″, approximately from the radial distance R3 to the radial distance R4. The helical projection 336″ and the follower 340″ of the fourth ramp 310 extend radially from approximately the radial distance R4 to a radial distance R5.
The inner cylindrical surface 335″′ of the fifth ramp 312 is disposed approximately at the radial distance R4, and the outer cylindrical surface 338″′ of the fifth ramp 312 is disposed approximately at the radial distance R5. The helical track 348″′, the deployment stop 350″′, and the retraction stop 352″′ of the fifth ramp 312 extend radially between the inner and outer cylindrical surfaces 335″′, 338″′, approximately from the radial distance R4 to the radial distance R5. The helical projection 336″′ and the follower 340″′ of the fifth ramp 312 extend radially from approximately the radial distance R5 to a radial distance R6. In some implementations, the helical projection 336″′ and the follower 340″′ may be omitted from the fifth ramp 312 (the last ramp).
“Approximately” in the context of the radial distances R1-R6 should be understood to mean within tolerances that allow the nesting ramps 302 to nest, e.g., to fit one inside the other in a graduated fashion. Clearance between adjacent nest ramps 302 is nominal.
The radial distance R6 is larger than the radial distance R5; the radial distance R5 is larger than the radial distance R4; the radial distance R4 is larger than the radial distance R3; the radial distance R3 is larger than the radial distance R2; the radial distance R2 is larger than the radial distance R1. In the illustrated implementation, R1 is about 2.36 inches (about 60 mm), R2 is about 2.48 inches (about 63 mm), R3 is about 2.60 inches (about 66 mm), R4 is about 2.72 inches (about 69 mm), R5 is about 2.83 inches (about 72 mm), and R6 is about 2.95 inches (about 75 mm). In other implementations, the radial distance R1 may be between about 1.72 inches (43.69 mm) and about 3.72 inches (94.49 mm), with the remaining radial distances R2-R6 being incrementally larger than the previous radial distance by about 0.05 to about 0.3 inches (1.27 to 7.62 mm). In other implementations, the radial distance R1 may be between about 1.0 inches (54.4 mm) and about 4.0 inches (101.6 mm), with the remaining radial distances R2-R6 being incrementally larger than the previous radial distance by about 0.05 to about 0.3 inches (1.27 to 7.62 mm). “About” should be understood to mean +/−0.1 inches in the context of radial distance.
The fifth ramp 312 (or the most distal of the nesting ramps 302 if a different number of ramps is employed) may be directly and fixedly coupled to the guard 40. In other implementations, the fifth ramp 312 may be indirectly coupled to the guard 40, and/or may be directly or indirectly coupled to other components of the blade module 28, such as the blade holder 46. The motor 36 may be fixed to, and supported by, the guard 40, which may include a degree of movement or damping to adapt to vibrations, external force, etc., or may be rigidly fixed. The motor 36 is disposed in a receptacle 354 defined by the nesting ramps 302, which may save space, particularly in the axial direction of the axis C.
The second ramp 306 hangs (e.g., by gravity) from the first ramp 304. In turn, the third ramp 308 hangs from the second ramp 306. In turn, the fourth ramp 310 hangs from the third ramp 308. In turn, the fifth ramp 312 hangs from the fourth ramp 310. In turn, the guard 40 hangs from the fifth ramp 312. In turn, the guard 40 supports the motor 36 and, in turn, the motor 36 drives the blade holder 46 and the blade(s) 34.
The height adjustment mechanism 290 may include one or more resilient members (not shown), such as damping members (e.g., foam, rubber, elastic material, tape, or the like), biasing members such as coil springs (as illustrated), one or more leaf springs, one or more cup springs, or any other type of spring or damping member, or the like, to inhibit the nesting ramps 302 from separating from each other. The height adjustment mechanism 290 may include one or more friction members (not shown), to inhibit the nesting ramps 302 from separating from each other in the axial direction of the axis C. The friction members may be separate components from the nesting ramps 302 or may be integrated with the nesting ramps 302 to provide engaging friction surfaces therebetween. The resilient members and/or friction members may be disposed in the helical tracks 348348′, 348″, 348″′, or any other location, such as in the receptacle 354 or outside the nesting ramps 302. Friction between the nesting ramps 302 themselves may inhibit the nesting ramps 302 from separating from each other in the axial direction of the axis C. In any case, the resilient/damping/biasing/friction member(s) and/or the arrangement of nesting ramps 302 may allow a degree of movement or damping to adapt to vibrations, external force, etc. For example, the degree of movement or damping may allow the cutting module 30 to move resiliently or be dampened when the blade 34, blade holder 46, or guard 40 hits a hard object.
In the illustrated implementation, the fifth ramp 312, the motor 36, the drive shaft 38, the guard 40, the blade holder 46, and the blade 34 move together as one unit in the direction of the axis C in response to movement of the manual actuator 292.
For example, the height adjustment mechanism 290 is configured such that the blade 34 is displaced in the axial direction of the axis C about 1.5 inches (38 mm) or more in response to an angular range of 180 degrees of rotation of the manual actuator 292. In other implementations, the blade 34 may be displaced in the axial direction of the axis C about 1.57 inches (40 mm) or more in response to 180 degrees of rotation of the manual actuator 292.
The cutting module 30 is modular and can be removed from the lawn mower 12 as a unit and replaced as a unit.
In some implementations, the first ramp 304 may be driven by a servomotor (not shown). In such an implementation, the manual actuator 292 need not be employed, and the height adjustment mechanism 290 is controlled electronically through the servomotor by way of the controller 200.
In operation, blade height adjustment may be achieved manually by an operator or electronically by way of the servomotor. For manual adjustment, the operator engages the grip surface 294 of the manual actuator 292 and moves the manual actuator 292 (e.g., rotates the manual actuator 292 about the central axis C in the illustrated implementation). The operator rotates the manual actuator 292 in the first direction 328 (e.g., clockwise) to lower the blade 34 (or other implement) and in a second direction 330 (e.g., counterclockwise) to raise the blade 34 (or other implement).
To return the blade 34 towards the raised position, the first ramp 304 is rotated in the second direction 330. The process of extending the height adjustment mechanism 90 from the retracted position to the extended position described above now occurs in reverse order. Initially, the first ramp 304 rotates together as one unit with the second ramp 306, the third ramp 308, and the fourth ramp 310. The follower 340″ of the fourth ramp 310 moves along the helical track 348″′ of the fifth ramp 312 until the retraction stop surface 346″ engages the retraction stop 352″′. Now, the fourth ramp 310 stops rotating about the axis C, and continued rotation of the first ramp 304 now causes only the second and third ramps 306, 308 to rotate. The process continues until the nesting ramps 302 return to the retracted position and the blade 34 is fully raised. Thus, axial retracting motion is transferred to adjacent ones of the fifth through second ramps 312, 310, 308, 306 serially (one after another in adjacent order) and one at a time.
Thus, in one aspect, the disclosure provides a robotic garden tool, including: a deck; an implement coupled to the deck; a motor configured to drive the implement; and a height adjustment mechanism configured to control movement of the implement with respect to the deck independently from the driving of the implement, the height adjustment mechanism including nesting ramps.
The robotic garden tool of any aspect, wherein the nesting ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement with respect to the deck, and the extended position corresponds with a second position of the implement with respect to the deck, wherein the first position is different from the second position.
The robotic garden tool of any aspect, wherein the motor is configured to drive the implement when the implement is in the first position and when the implement is in the second position.
The robotic garden tool of any aspect, wherein the nesting ramps include at least a first ramp and a second ramp, the first ramp including a first helical surface and the second ramp including a second helical surface.
The robotic garden tool of any aspect, wherein the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement with respect to the deck, and the extended position corresponds with a second position of the implement with respect to the deck, wherein the first position is different from the second position.
The robotic garden tool of any aspect, wherein each of the first and second ramps is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is smaller than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp with respect to the second ramp.
The robotic garden tool of any aspect, wherein the nesting ramps include at least a first ramp and a second ramp, the first and second ramps being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is smaller than a second radius defined from the axis to the second ramp to allow nesting of the first ramp into the second ramp.
The robotic garden tool of any aspect, wherein the first ramp is configured to nest in the second ramp in a retracted position.
The robotic garden tool of any aspect, wherein the first and second ramps are movable with respect to each other between a retracted position and an extended position.
In another aspect, the disclosure provides a cutting module for a robotic garden tool, including: a motor configured to drive an implement; and a height adjustment mechanism configured to move the implement independently from the driving of the implement, the height adjustment mechanism including nesting ramps.
The cutting module of any aspect, wherein the nesting ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement, and the extended position corresponds with a second position of the implement, wherein the first position is different from the second position.
The cutting module of any aspect, wherein the motor is configured to drive the implement when the implement is in the first position and when the implement is in the second position.
The cutting module of any aspect, wherein the nesting ramps include at least a first ramp and a second ramp, the first ramp having a first helical surface and the second ramp having a second helical surface.
The cutting module of any aspect, wherein the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the implement, and the extended position corresponds with a second position of the implement, wherein the first position is different from the second position.
The cutting module of any aspect, wherein each of the first and second ramps is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is smaller than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp with respect to the second ramp.
The cutting module of any aspect, wherein the nesting ramps include at least a first ramp and a second ramp, the first and second ramps being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is smaller than a second radius defined from the axis to the second ramp to allow nesting of the first ramp with respect to the second ramp.
The cutting module of any aspect, wherein the first ramp is configured to nest in the second ramp in a retracted position.
The cutting module of any aspect, wherein the first and second ramps are movable with respect to each other between a retracted position and an extended position.
In yet another aspect, the disclosure provides a robotic lawn mower, including: a deck; a blade configured for movement with respect to the deck; a motor configured to rotate the blade about an axis of rotation, wherein the rotation is independent from the movement with respect to the deck; and a height adjustment mechanism configured to control the movement of the blade with respect to the deck, the height adjustment mechanism including nesting ramps.
The robotic lawn mower of any aspect, wherein the nesting ramps include at least a first ramp and a second ramp, wherein each of the first and second ramps is rotatable about an axis, wherein the first and second ramps are movable with respect to each other between a retracted position and an extended position, and wherein the retracted position corresponds with a first position of the blade, and the extended position corresponds with a second position of the blade, wherein the first position is different from the second position.
The robotic lawn mower may additionally or alternatively include any aspect of any cutting module and/or of any robotic garden tool, in any combination, that is disclosed herein.
Although the disclosure has been described in detail with reference to preferred implementations, variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described.
Thus, the disclosure provides, among other things, a garden tool 12, such as an autonomous lawn mower, with blade height adjustment using nesting ramps 302.
This application claims priority to co-pending U.S. Provisional Patent Application No. 63/320,599, filed on Mar. 16, 2022 (Atty. Docket No. 206737-9030-US02), and to co-pending U.S. Provisional Patent Application No. 63/321,536, filed on Mar. 18, 2022 (Atty Docket No. 206737-9030-US03), the entire contents of all of which are incorporated herein by reference.
Number | Date | Country | |
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63320599 | Mar 2022 | US | |
63321536 | Mar 2022 | US |