CN116762554A

CN116762554A - Robotic garden tool with appliance height adjustment

Info

Publication number: CN116762554A
Application number: CN202310270777.9A
Authority: CN
Inventors: 吴灏林
Original assignee: Techtronic Cordless GP
Current assignee: Techtronic Cordless GP
Priority date: 2022-03-16
Filing date: 2023-03-16
Publication date: 2023-09-19

Abstract

A robotic garden tool includes a platform, an implement movably coupled to the platform, a motor configured to drive the implement, and a height adjustment mechanism configured to control movement of the implement relative to the platform. The height adjustment mechanism includes an interface that engages the gear teeth.

Description

Robotic garden tool with appliance height adjustment

Cross Reference to Related Applications

The present application claims priority from co-pending U.S. provisional patent application number 63/320,599 (attorney docket number 206737-9030-US 02) filed on month 3 of 2022 and from co-pending U.S. provisional patent application number 63/321,536 (attorney docket number 206737-9030-US 03) filed on month 3 of 2022, the entire contents of all of which are incorporated herein by reference.

Background

The present disclosure relates to a garden tool, such as a robotic lawnmower, having a driven implement, such as a blade for cutting grass or other plants.

Disclosure of Invention

In one aspect, the present disclosure provides a robotic garden tool. The robotic garden tool includes a platform, an implement movably coupled to the platform, a motor configured to drive the implement, and a height adjustment mechanism configured to control movement of the implement relative to the platform. The height adjustment mechanism includes an interface that engages the 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 effect movement of the second set of gear teeth; the second set of gear teeth is configured to be driven by a servo motor; the height adjustment mechanism further comprises a manual actuator configured to move in response to manual actuation by an operator, wherein the implement is configured to move relative to the platform in response to manual actuation of the manual actuator; the interface of the meshing gear teeth comprises a spiral rack and a bevel gear; the helical rack defines a central axis and is configured to rotate about the central axis; the bevel gear is biased into engagement with the helical rack and configured to move at least axially relative 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 servo motor configured to drive the bevel gear or the helical rack; the interface of the meshing gear teeth includes a linear rack and a circular gear; the circular gear is configured to be manually actuated to effect movement of the linear rack; the height adjustment mechanism further includes a servo motor configured to drive the linear rack or the circular gear; rotation of at least a portion of the interface about the central axis causes the appliance to move by at least 0.75 inch per 90 degree rotation; the interface may include a manual actuator.

In another aspect, the present disclosure provides a cutting module for a robotic garden tool. The cutting module includes a motor configured to drive the implement and a height adjustment mechanism configured to move the implement independent of the drive of the implement. The height adjustment mechanism includes an interface that engages the 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 effect movement of the second set of gear teeth; the second set of gear teeth is configured to be driven by a servo motor; the interface of meshing gear teeth includes a helical rack and bevel gear interface or a linear rack and circular gear interface.

In another aspect, the present disclosure provides a robotic lawnmower. The robotic lawnmower includes a platform, a blade configured to move relative to the platform, and a motor configured to rotate the blade about an axis of rotation. The rotation is independent of the movement relative to the platform. The robotic lawnmower further includes a height adjustment mechanism configured to control movement of the blade relative to the platform. The height adjustment mechanism includes an interface that engages the gear.

Alternatively or additionally, in any combination: the interface of the meshing gears includes a first set of gear teeth and a second set of gear teeth, wherein the first set of gear teeth are configured to mesh with the second set of gear teeth; the first set of gear teeth is configured to be manually actuated to effect movement of the second set of gear teeth; the second set of gear teeth is configured to be driven by a servo motor; the height adjustment mechanism further comprises a manual actuator configured to move in response to manual actuation by an operator, wherein the blade is configured to move relative to the platform in response to manual actuation of the manual actuator; the interface of the meshing gear comprises a spiral rack and a bevel gear; the helical rack defines a central axis and is configured to rotate about the central axis; the bevel gear is biased into engagement with the helical rack and configured to move at least axially relative to the central axis; the blades are configured to move at least axially in response to axial movement of the bevel gear; the height adjustment mechanism further includes a servo motor configured to drive the bevel gear or the helical rack; the interface of the meshing gears comprises a linear rack and a circular gear; the circular gear is configured to be manually actuated to effect movement of the linear rack; the height adjustment mechanism further includes a servo motor configured to drive the linear rack or the circular gear; rotation of at least a portion of the interface about the central axis causes the appliance to move by at least 0.75 inch per 90 degree rotation; the interface may include a manual actuator.

In yet another aspect, the present disclosure provides a robotic garden tool. The robotic garden tool includes a platform, an implement coupled to the platform, a motor configured to drive the implement, and a height adjustment mechanism configured to control movement of the implement relative to the platform independent of the drive of the implement. The height adjustment mechanism includes a nesting ramp.

Alternatively or additionally, in any combination: the nesting ramps are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement relative to the platform and the extended position corresponds to a second position of the implement relative to the platform, 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 ramp includes 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 ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement relative to the platform and the extended position corresponds to a second position of the implement relative to the platform, wherein the first position is different from the second position; each of the first ramp and the second ramp is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is less than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp relative to the second ramp; the nesting ramp includes at least a first ramp and a second ramp, the first ramp and the second ramp being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is less 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 the retracted position; the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position.

In yet another aspect, the present disclosure provides a cutting module for a robotic garden tool. The cutting module includes a motor configured to drive the implement and a height adjustment mechanism configured to move the implement independent of the drive of the implement. The height adjustment mechanism includes a nesting ramp.

Alternatively or additionally, in any combination: the nesting ramp is movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement and the extended position corresponds to 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 ramp includes at least a first ramp having a first helical surface and a second ramp having a second helical surface; the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement and the extended position corresponds to a second position of the implement, wherein the first position is different from the second position; each of the first ramp and the second ramp is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is less than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp relative to the second ramp; the nesting ramp includes at least a first ramp and a second ramp, the first ramp and the second ramp being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is less than a second radius defined from the axis to the second ramp to allow nesting of the first ramp relative to the second ramp; the first ramp is configured to nest in the second ramp in the retracted position; the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position.

In yet another aspect, the present disclosure provides a robotic lawnmower. The robotic lawnmower includes a platform, a blade configured to move relative to the platform, and a motor configured to rotate the blade about an axis of rotation. The rotation is independent of the movement relative to the platform. The robotic lawnmower further includes a height adjustment mechanism configured to control movement of the blade relative to the platform. The height adjustment mechanism includes a nesting ramp.

Alternatively or additionally, in any combination: the nesting ramp comprises at least a first ramp and a second ramp, wherein each of the first ramp and the second ramp is rotatable about an axis, wherein the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the blade and the extended position corresponds to a second position of the blade, wherein the first position is different from the second position; the nesting ramps are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the blade relative to the platform and the extended position corresponds to a second position of the blade relative to the platform, 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 ramp includes 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 ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the blade relative to the platform and the extended position corresponds to a second position of the blade relative to the platform, wherein the first position is different from the second position; each of the first ramp and the second ramp is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is less than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp relative to the second ramp; the nesting ramp includes at least a first ramp and a second ramp, the first ramp and the second ramp being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is less 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 the retracted position; the first ramp and the second ramp are movable relative 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.

Drawings

FIG. 1 is a top perspective view of an autonomous lawn mower embodying the present disclosure.

FIG. 2 is a cross-sectional view of the autonomous lawn mower of FIG. 1 taken through line 2-2 in FIG. 1.

Fig. 3 is a schematic diagram illustrating a control system of the lawn mower of fig. 1.

Fig. 4 is a perspective view of a cutting module having a height adjustment mechanism of the autonomous lawn mower of fig. 1.

Fig. 5 is a perspective view of the cutting module of fig. 4 with another embodiment of a height adjustment mechanism.

Fig. 6 is a perspective view of a portion of the height adjustment mechanism of fig. 4 or 5.

FIG. 7 is a top perspective view of a cutting module having another embodiment of a height adjustment mechanism of the autonomous lawn mower of FIG. 1 in a first position and with a guard shown transparent for illustration purposes.

Fig. 8 is a top perspective view of a cutting module having the height adjustment mechanism of fig. 7, the height adjustment mechanism being in a second position.

Fig. 9 is a top perspective view of a cutting module having the height adjustment mechanism of fig. 7, the height adjustment mechanism being in a third position.

Fig. 10 is a cross-sectional view of a cutting module having the height adjustment mechanism of fig. 7.

Fig. 11 is a bottom exploded perspective view of a portion of the height adjustment mechanism of fig. 7.

Fig. 12 is a bottom orthogonal view of a portion of the height adjustment mechanism of fig. 7.

Fig. 13 is a top perspective view of a portion of the height adjustment mechanism of fig. 12.

Fig. 14 is a side view of the height adjustment mechanism of fig. 7 in a first position.

Fig. 15 is a side view of the height adjustment mechanism of fig. 8 in a second position.

Fig. 16 is a side view of the height adjustment mechanism of fig. 9 in a third position.

Fig. 17 is a top view of the height adjustment mechanism of fig. 14 in a first position.

Detailed Description

Before any embodiments 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 embodiments 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 is for the purpose of description and should not be regarded as limiting. The terms "about," "approximately," "substantially," and the like should be construed to be within standard tolerances, as would be understood by one of ordinary skill in the art, unless other definitions are provided for the following specific context. The term "helical surface" is defined herein as a surface comprising a helical curve. A "spiral curve" is a curve on a conical or cylindrical surface (which may be an imaginary conical or cylindrical surface for definition purposes only) other than a two-dimensional arc. Thus, "spiral" is meant to include a spiral curve on a surface.

Figures 1-2 illustrate a garden tool system 10. For example, the garden tool system 10 may include a garden tool 12, such as a lawn mower 12 (as shown), or in other embodiments may include tools for sweeping debris, cleaning debris, collecting debris, moving debris, and the like. The debris may include plants (such as grass, leaves, flowers, stems, weeds, twigs, branches, etc. and their trimmings), dust, dirt, work site debris, snow, etc. For example, other embodiments of the garden tool 12 may include a vacuum cleaner, a trimmer, a string trimmer, a brush cutter, a hedge trimmer, a sweeper, a cutter, a plow, a debris blower, a snow blower, and the like. In the illustrated embodiment, the garden tool system 10 includes a lawn mower 12 and a charging station 48. The garden tool 12 may be autonomous, semi-autonomous, or non-autonomous.

For example, as illustrated in fig. 3, the lawn mower 12 may include a controller 200 having a programmable processor 202 (e.g., a microprocessor, microcontroller, or another suitable programmable device), a memory 204, and a human interface 216 (which may include a mobile device). For example, memory 204 may include program storage area 206 and data storage area 208. Program storage area 206 and data storage area 208 may include a combination of different types of memory, such as read only memory ("ROM"), random access memory ("RAM") (e.g., dynamic RAM [ "DRAM"; ]Synchronous DRAM [ "SDRAM"]Etc.), an electrically erasable programmable read-only memory ("EEPROM"), a flash memory, a hard disk, an SD card or other suitable magnetic memory device, an optical memory device, a physical memory device, an electronic memory device, or other data structure. The controller 200 may also or alternatively include integrated circuits and/or analog devices (e.g., transistors, comparators, operational amplifiers, etc.) to perform the logic and control signals described herein. The controller 200 includes a plurality of inputs 210 and outputs 212 to and from various components of the lawn mower 12. The controller 200 is configured to provide control signals to the output 212 and receive data and/or signals (e.g., sensor data from the sensor 214, user input signals, etc.) from the input 210. The input 210 and output 212 are communicated, for example, by hard-wired and/or wireless communication (such as by satellite, internet, mobile telecommunications technology, frequency, wavelength, etc,Etc.) communicates with the controller 200. The controller 200 may include a navigation system that may include a Global Positioning System (GPS), a beacon, a sensor such as an image sensor, an ultrasonic sensor, a line sensor, and an algorithm for navigating an area to be mowed One or more of the following. However, in other embodiments, the lawn mower 12 may be non-autonomous.

Referring to fig. 2, the lawn mower 12 includes a platform 14 to support various components of the lawn mower 12, as will be described in greater detail below. The lawn mower 12 includes at least one prime mover 16 to provide traction to move the lawn mower 12 over a support surface, such as a charging station 48 or a lawn to be mowed. At least one prime mover 16 may be supported by the platform 14. For example, in the illustrated embodiment, the at least one prime mover 16 may include one or more electric motors 16. However, in other embodiments, prime mover 16 may include another type of motor, gasoline engine, or the like, in any suitable number and combination.

The lawn mower 12 also includes a plurality of wheels 18 (fig. 1) that may be supported by the platform (fig. 2) for converting traction into movement of the lawn mower 12 over a supporting surface. In the illustrated embodiment, each of the plurality of wheels 18 is supported by a tire 22. However, in other embodiments, the plurality of wheels 18 may support any combination of one or more tires, continuous tracks, and the like. The plurality of wheels 18 includes two front wheels 20a and two rear wheels 20b, although other numbers of wheels may be employed in other embodiments. In the illustrated embodiment, each of the two rear wheels 20b is operatively coupled to its own prime mover 16 (such as two electric motors, one for each corresponding rear wheel 20 b) to apply torque thereto, and the two front wheels 20a are not driven. However, in other embodiments, other torque transfer devices may be used having any number and combination of driven and non-driven wheels, any number of wheels driven by a single prime mover, and any number of prime movers.

The lawn mower 12 includes a power source 24 (fig. 2), such as a battery, for powering the at least one prime mover 16 such that the lawn mower 12 can perform lawn mowing operations in a cordless manner. Power source 24 may include one or more lithium ion battery packs and/or other battery chemistries. The power source 24 may be removable from the lawn mower 12. In other embodiments, at least one prime mover 16 may be powered by other power sources (such as solar panels, fuel cells, compressed fluid, fuel, etc.). The lawn mower 12 includes a battery charging contact 26 for receiving electrical charge from an external power source (not shown) to charge the power source 24.

Referring to fig. 1 and 2, the charging station 48 includes a docking pad 194 and a battery charging terminal 196. The docking pad 194 defines a generally planar surface 198, wherein a "generally planar surface" is defined as a portion that provides a sufficient planar surface, i.e., is comprised of a single continuous surface or a plurality of separate (discontinuous) surfaces, for the lawn mower 12 to travel thereon and to support the lawn mower during a charging operation. The battery charging terminal 196 is configured to engage with the battery charging contact 26 on the lawn mower 12 to provide an electrical connection therebetween to charge the power source 24 (e.g., a battery).

The lawn mower 12 includes a cutting module 30 (fig. 2) which may be supported by the platform 14. As best shown in fig. 4, the cutting module 30 includes a cutting module mount 32 that is fixed relative to the platform 14 or formed as part of the platform 14. Referring to fig. 2, the cutting module 30 further includes a blade 34 and a motor 36 configured to move the blade 34 about the axis of rotation a. The cutting module 30 includes a blade module 28 (which is one example of a driven implement herein) and a motor 36 configured to drive the blade module 28. In the illustrated embodiment, the blade module 28 includes one or more blades 34, and a motor 36 drives the blade module 28 about the axis of rotation a. In other embodiments, the vane module 28 includes a reciprocating trimming unit (not shown) having linearly reciprocating trimming vanes, and the motor 36 drives the trimming vanes of the trimming unit to reciprocally move. In yet further embodiments, blade module 28 includes a string (not shown), as in a string trimmer, and motor 36 drives the string about axis of rotation a. In yet further embodiments, the blade module 28 includes roller blades (not shown), such as reel blades or squirrel cage blades, and the motor 36 drives the roller blades to roll or rotate about an axis that is substantially parallel (e.g., substantially horizontal) to the support surface. In yet further embodiments, the blade module 28 includes an auger (not shown), such as a snow blower auger, and the motor 36 drives the auger to roll or rotate about an axis that is substantially parallel (e.g., substantially horizontal) to the support surface. In yet further embodiments, blade module 28 includes a fan (not shown), such as a blower fan, and motor 36 drives the fan in rotation. In addition to the examples given above, other types of blades are possible. In addition, other types of implements are possible, including the blades described above, as well as other non-blade implements driven by the motor 36, such as brushes.

The motor 36 includes a rotatable drive shaft 38 that is operably coupled to the vane module 28 (or any other appliance according to any embodiment of the present disclosure). In the illustrated embodiment, the drive shaft 38 is disposed coaxially with the axis of rotation a. In other embodiments, the drive shaft 38 may be disposed parallel (e.g., offset) or transverse to the axis of rotation a. The rotation axis a defines an axial direction B. The axial direction B is typically a vertical direction relative to a support surface on which the lawn mower 12 is traveling, such as an up-down direction relative to gravity, when the lawn mower 12 is in use. However, in certain embodiments, the axis of rotation a (and thus the axial direction B) may be inclined with respect to the vertical, for example 1 to 10 degrees, preferably 3 to 8 degrees, and more preferably 5 to 6 degrees. In some embodiments, the rotation axis a may be inclined forward in the traveling direction with respect to the vertical direction.

Blade module 28 (fig. 2) may include one or more blades 34 supported by a blade support 46. In the illustrated embodiment, each of the one or more blades 34 is configured to cut vegetation, such as grass and other plants. In some embodiments, each of the one or more blades 34 may include one or more flail-type blades and/or strings for cutting vegetation. In still further embodiments, one or more blades 34 may include any other type of blade for cutting vegetation, such as a blade cutter, a saw tooth cutter, a roller cutter, any of the cutters described above, or any other cutter. In still other embodiments, the blade support 46 may support other types of blades, such as fan blades, augers, and the like. In yet further embodiments, the blade support 46 may be integrally formed with one or more blades, one or more blades edges, teeth, one or more strings, or any other cutter(s) in any combination.

The cutting module 30 further includes a height adjustment mechanism 90 (fig. 4-5) for at least partially moving the blade 34 or other implement up and down in the axial direction B ("at least partially" means that the blade 34 has at least a component of movement in that direction, which may be vertical or inclined, but may or may not additionally move in other directions). The height adjustment mechanism 90 includes a manual actuator 92 configured to move in response to manual actuation by an operator. The operator's hand may reach the manual actuator 92 from outside the lawn mower 12 for manual engagement, as illustrated in fig. 1. For example, the manual actuator 92 includes a gripping surface 94, such as a triangular tab in the illustrated embodiment, that is disposed external to the lawn mower 12, as illustrated in fig. 1. In the illustrated embodiment, the manual actuator 92 is rotatable about the axis of rotation a of the blade. However, in other embodiments, the manual actuator 92 may be rotatable about a different axis, which may be parallel to or transverse to the axis of rotation a of the blade 34. The vane 34 is configured to move in the axial direction B in response to movement of the manual actuator 92, as will be described in more detail below. In the illustrated embodiment, the blade 34 is movable approximately 1.57 inches (40 mm) in the axial direction B between a raised position in which the blade 34 is fully raised and a lowered position (fig. 4) in which the blade 34 is fully lowered. In some embodiments, the vane 34 is movable in the axial direction B by at least 1.5 inches (38.1 mm), and may be movable in the axial direction B by at least 1.57 inches (40 mm), and in some embodiments may be movable in the axial direction B by more than 1.57 inches (40 mm). In certain embodiments, the cutting height (the height from the blade 34 to the ground on which the lawn mower 12 rests) varies from about 1.96 inches (50 mm) from the ground in the lowered position to about 3.54 inches (90 mm) from the ground in the raised position. In certain embodiments, the cutting height varies from about 0.78 inches (20 mm) from the ground in the lowered position to about 2.36 inches (60 mm) from the ground in the raised position.

Referring to the embodiment of fig. 4, the height adjustment mechanism 90 further includes an interface 100 having meshing gear teeth. The manual actuator 92 is operably coupled to the interface 100. In the illustrated embodiment, the interface 100 may be referred to as a helical rack-bevel gear interface 100 and is defined by a helical rack 102 and a bevel gear 104. In other embodiments, some of which are described in more detail herein, other types of interfaces 100 may be employed. For example, spur gears may be used instead of bevel gears. Bevel gear 104 includes bevel teeth 106 and bevel shaft 107. Bevel gear 104 is rotatable about a gear shaft axis D defined by a bevel shaft 107. In the illustrated embodiment, the helical rack 102 is rotatable about the central axis C, and the bevel gear 104 is axially translatable relative to the central axis C while being rotatable about the gear shaft axis D. The helical rack 102 spirals at least partially about the central axis C and includes a plurality of rack teeth 108 configured to engage with the bevel teeth 106 on the bevel gear 104. In the illustrated embodiment, the manual actuator 92 is rotatable about a central axis C coincident with the axis of rotation a. Thus, in the illustrated embodiment, the central axis C also defines an axial direction B. However, in other embodiments, the central axis C and the rotation axis a need not coincide, and may be offset (parallel) or transverse to each other.

In the illustrated embodiment, the helical rack 102 includes a helical surface 109 that extends 360 degrees about the central axis C. The rack teeth 108 protrude from the helical surface 109. In other embodiments, the helical surface 109 may have other configurations. For example, the helical surface 109 may extend less than 360 degrees around the central axis C to increase the pitch. As another example, the helical surface 109 may be divided into two separate helical surfaces, each extending 180 degrees around the central axis C, or three separate helical surfaces, each extending 120 degrees around the central axis C, etc., and a corresponding number of bevel gears 104 may be employed. In the illustrated embodiment, the helical surface 109 has a pitch angle of about 114.3 degrees per inch (where "about" refers to +/-10 degrees per inch) (pitch angle of about 4.5 degrees per millimeter). In some embodiments, the pitch angle may be between about 50.8 degrees per inch and about 152.4 degrees per inch (between about 2 degrees per millimeter and about 6 degrees per millimeter). The helical surface 109 has a radius R (from the central axis C, as shown in fig. 4) of about 2.36 inches (where "about" means +/-0.2 inches) (radius R is about 60 mm). In other embodiments, the radius R may be between about 0.78 inches and about 9.9 inches (about 20mm-250 mm), or between about 1.1 inches and about 7.9 inches (about 30mm-200 mm), or between about 1.5 inches and about 5.9 inches (about 40mm-150 mm), or between about 1.9 inches and about 3.9 inches (about 50mm-100 mm), or between about 2.3 inches and about 3.2 inches (about 60mm-80 mm). For example, the interface 100 is configured such that the vane 34 is displaced about 1.5 inches (38 mm) or more in the axial direction B in response to an angular range of 180 degrees of rotation of the manual actuator 92. In other embodiments, the vane 34 may be displaced about 1.57 inches (40 mm) or more in the axial direction B in response to 180 degrees of rotation of the manual actuator 92.

Referring to fig. 4, the interface 100 is disposed within a cylindrical volume 110 defined circumferentially by the helical rack 102 (e.g., by the helical surface 109) and is bounded axially (e.g., relative to the central axis C) by an upper distal end 112a and a lower distal end 112b of the helical rack 102. In the illustrated embodiment, the axis of rotation a intersects the cylindrical volume 110. In the illustrated embodiment, the cylindrical volume 110 is centered with respect to the axis of rotation a. In other embodiments, the rotation axis a may be disposed at other locations intersecting the cylindrical volume 110, such as parallel to the central axis C or transverse to the central axis C (e.g., if the rotation axis a is tilted as described above). In yet further embodiments, the axis of rotation a may be transverse to the central axis C and need not intersect the cylindrical volume 110. In the illustrated embodiment, the axis of rotation a intersects the manual actuator 92, and more specifically is coaxial with the manual actuator 92. Furthermore, the manual actuator 92 is rotatable about the central axis C, and thus also about the rotation axis a. However, in other embodiments, other configurations of the manual actuator 92 are possible. For example, in other embodiments, the central axis C need not be coaxial with the rotational axis a of the blade, and may be parallel (offset) or transverse to the rotational axis a of the blade.

The height adjustment mechanism 90 includes a motor mount 114 configured to support the motor 36 in a generally fixed relationship therewith, which may include a degree of movement or damping to accommodate vibrations, external forces, etc., or may be rigidly fixed. The motor mount 114 is axially slidable relative to the cutting module mount 32 in the direction of the central axis C. The motor mount 114 may be fixed against rotational movement relative to the platform 14 such that the motor mount 114 is configured to translate in the direction of the axis C without rotating relative to the platform 14. In the illustrated embodiment, the motor mount 114 includes one or more protrusions 118 that guide the movement of the motor mount 114 along a track 120 in the cutting module mount 32 in the direction of the axis C. The motor mount 114 is movable between a raised position (fig. 4) in which the blade 34 is fully raised and a lowered position in which the blade 34 is fully lowered. In the illustrated embodiment, the motor mount 114 also supports the drive shaft 38 and the vane 34 in fixed relation thereto such that the motor mount 116, the motor 36, the drive shaft 38, and the vane 34 move together as a unit in the direction of the axis C in response to movement of the manual actuator 92.

In the illustrated embodiment, the bevel gear is rotatably coupled to the motor mount 114 by a bevel shaft 107. The manual actuator 92 is operably coupled to a helical rack 102. As illustrated, the manual actuator 92 is fixed to the helical rack 102 such that the manual actuator 92 and the helical rack 102 rotate together as a unit. However, in other embodiments, an intermediate transmission may be provided between the manual actuator 92 and the helical rack 102.

Thus, in the illustrated embodiment, manual rotation of the manual actuator 92 causes rotation of the helical rack 102. Rack teeth 108 are configured to engage with bevel teeth 106. Rotation of the helical rack 102 thereby causes rotation of the bevel gear 104 about the gear shaft axis D. As the helical rack 102 rotates about the central axis C, the bevel gear 104, which is upwardly biased from the support surface, rises and falls in the direction of the central axis C to follow the helical rack 102. The motor mount 114 rises and falls in the direction of the central axis C with the bevel gear 104, as does any combination of any element secured to the motor mount 114, such as one or more of the motor 36, the vane 34, the vane mount 46, and the like.

In other embodiments, bevel gear 104 may be driven by a servo motor 122, which is schematically illustrated in fig. 4. The servo motor 122 is configured to drive the bevel gear 104 to rotate about the gear shaft axis D. In this embodiment, the manual actuator 92 need not be employed, and the height adjustment mechanism 90 is electronically controlled by the servo motor 122 via the controller 200. In yet further embodiments, the servo motor 122 may be configured to drive the helical rack 102.

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 upward (away from the support surface) in the direction of the central axis C. The one or more biasing members 116 restore the motor mount 114 to its uppermost position (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 projections 118 and the cutting module mount, and each of the one or more biasing members 116 is received in a respective rail 120. In the illustrated embodiment, the one or more biasing members 116 are each directly engaged with the cutting module mount 32 and the motor mount 114; however, in other embodiments, indirect engagement may be employed. The one or more biasing members 116 allow the cutting module 30 to float relative to the platform 14 and may thus allow the cutting module 30 to move in more than just the direction of the central axis C.

Referring to fig. 6, which illustrates another embodiment of a manual actuator 92 having a gripping surface 94', the height adjustment mechanism 90 may include a ratcheting mechanism 70 operatively coupled to the manual actuator 92 for producing audible and/or tactile feedback and maintaining the manual actuator 92 in a plurality of discrete angular positions. Indicia (not shown), such as height indicators, may be provided at predetermined rotational intervals of the manual actuator 92 corresponding to different cutting heights. As the manual actuator 92 rotates, the manual actuator 92 is also held at a fixed height (in the axial direction B) relative to the platform 14. In the illustrated embodiment, the ratcheting mechanism 70 includes spring-biased spheres 72 disposed about the periphery of the manual actuator 92 and extending radially from the outer peripheral surface 74 of the manual actuator 92. The spring biased ball 72 is biased radially outward from the peripheral surface 74 toward the cutting module mount 32 (or toward any other component coupled to or fixed relative to the platform 14, or toward the platform 14 itself). The illustrated ratcheting mechanism 70 includes ten spring-biased spheres 72 arranged at 36 degree intervals around a peripheral surface 74; however, in other embodiments, any number and spacing of one or more spring biased spheres 72 (or other ratcheting mechanism) may be employed. The ratchet lock mechanism 70 engages the cutting module mount 32 and aligns with an aperture 76 on the cutting module mount 32. In other embodiments, the aperture 76 may be provided on any other component coupled to or fixed relative to the platform 14, or on the platform 14 itself. The apertures 76 on the cutting module mount 32 may include notches (as shown), recesses, grooves, pockets, and the like. In the illustrated embodiment, two orifices 76 are employed in diametrically opposed positions; however, in other embodiments, any number of one or more apertures 76 arranged in any suitable fashion may be employed for engagement with the ratcheting mechanism 70. In yet further embodiments, the ratcheting mechanism 70 may be provided on the cutting module mount 32 (either on any other component coupled to or fixed relative to the platform 14, or on the platform 14 itself), and one or more apertures 76 may be provided on the manual actuator 92.

The cutting module 30 also includes a guard 40 (fig. 2 and 7) that covers a portion of the blade 34. The guard 40 may have any suitable configuration for covering a portion of the blade 34, and may cover a portion of the blade 34 at the bottom of the blade 34, a portion around the circumferential side of the blade 34, and/or a portion above the blade 34 in any combination. In the illustrated embodiment, the guard 40 is configured to move up and down in a fixed relationship with the blade 34 in response to movement of the manual actuator 92. However, in other embodiments, the guard 40 may remain fixed relative to the platform 14 as the blade 34 is adjusted.

The cutting module 30 is modular and may be removed from the lawn mower 12 as a unit and replaced as a unit.

Fig. 5 illustrates another embodiment of an interface 100' having meshing gear teeth. Only the differences between interface 100 and interface 100' will be described herein. It should be appreciated that the other features of the height adjustment mechanism 90 shown in fig. 4 and 6 are the same when used with the interface 100' shown in fig. 5 in place of the interface 100 shown in fig. 4. In the illustrated embodiment, the interface 100 'may be referred to as a linear rack-and-pinion interface 100' and is defined by a linear rack 132 and a pinion 134. In other embodiments, other types of interfaces 100' may be employed. Circular gear 134 includes gear teeth 136 and gear shaft 137. The manual actuator 92 may be rotatable about the central axis C and operatively coupled to the circular gear 134. The circular gear 134 is rotatable about a gear shaft axis D' defined by the gear shaft 137 in response to manual actuation of the manual actuator 92. The linear rack 132 includes a generally linear arrangement of rack teeth 138. The rack teeth 138 are configured to mesh with the gear teeth 136 such that rotation of the circular gear 134 causes linear movement of the linear rack 132, for example in the direction of the central axis C or in other linear directions in other embodiments. The motor mount 114 may be coupled to the linear rack 132 such that the motor mount 114 moves with the linear rack 132. All of the components supported by the motor mount 114 (as described above with respect to fig. 4) also move with the linear rack 132. In the illustrated embodiment, the linear rack 132 and the motor mount 114 move in the direction of the central axis C; however, in other embodiments, the motor mount 114 may move in other directions.

In some embodiments, the circular gear 134 may be driven by a servo motor 142, which is schematically illustrated in fig. 5. The servo motor 142 is configured to drive the circular gear 134 to rotate about the gear shaft axis D'. In this embodiment, the manual actuator 92 need not be employed, and the height adjustment mechanism 90 is electronically controlled by the controller 200 via the servo motor 142. In yet further embodiments, the servo motor 142 may be configured to drive the linear rack 132.

In operation, blade height adjustment may be accomplished manually by an operator or electronically by servo motors 122, 142. For manual adjustment, the operator engages the gripping 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 embodiment). At predefined angular intervals, the operator may hear and/or feel feedback from the manual actuator 92. For every 36 degree rotational angle interval, the blade height varies by approximately 0.314 inches (8 mm) (or more in some embodiments). The blade height varies by at least 1.5 inches (38 mm) or more in response to manual actuator 92 rotating 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 rotates the manual actuator in a second direction (e.g., counter-clockwise) to raise the blade 34 (or other implement). The second direction is opposite to the first direction. When the manual actuator 92 is rotated in the second direction, the biasing member 116 provides a force to return the blade 34 toward the raised position.

Although the present disclosure has been described in detail with reference to preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described.

Thus, the present disclosure provides, among other things, a garden tool 12, such as an autonomous lawn mower, having blade height adjustment.

Fig. 7-17 illustrate another embodiment of a height adjustment mechanism 290. The cutting module 30 may additionally or alternatively include a height adjustment mechanism 290 (fig. 7-17) for at least partially moving the blade 34 or other implement up and down in the axial direction B ("at least partially" means that the blade 34 has at least a component of movement in the direction, which may be vertical or inclined, but may or may not additionally move in other directions). The height adjustment mechanism 290 includes a manual actuator 292 (fig. 7) configured to move in response to manual actuation by an operator. The operator's hand may reach the manual actuator 292 from outside the lawn mower 12 for manual engagement, as illustrated in fig. 1. For example, the manual actuator 292 includes a gripping surface 294, such as a triangular tab in the illustrated embodiment, that is disposed external to the lawn mower 12, as illustrated in fig. 1. In the illustrated embodiment, the manual actuator 292 is rotatable about an axis C that may coincide with the rotational axis a of the blade. However, in other embodiments, the axis C may be offset parallel to the axis of rotation a or transverse to the axis of rotation a of the blade 34. The vane 34 is configured to move at least partially in the axial direction B in response to movement of the manual actuator 292, as will be described in more detail below. In the illustrated embodiment, the vane 34 is configured to move in an axial direction of the axis C, which in the illustrated embodiment is the same as the axial direction B. Thus, the terms "axial direction of axis C" and "axial direction B" may be used interchangeably herein. However, in other embodiments, the axial direction of axis C may be transverse to axial direction B.

In the illustrated embodiment, the blade 34 is movable approximately 1.57 inches (40 mm) in the axial direction of the axis C between a raised position (fig. 7 and 14) in which the blade 34 is fully raised and a lowered position (fig. 9 and 16) in which the blade 34 is fully lowered. The intermediate position (fig. 8 and 15) is disposed between the raised and lowered positions, and the vanes 34 are infinitely adjustable between the raised and lowered positions. In some embodiments, the blade 34 is movable in the axial direction of the axis C by at least 1.5 inches (38.1 mm), and may be movable in the axial direction of the axis C by at least 1.57 inches (40 mm), and in some embodiments may be movable in the axial direction of the axis C by more than 1.57 inches (40 mm). In certain embodiments, the cutting height (height from the blade 34 to the ground/support surface) varies from about 1.96 inches (50 mm) from the ground in the lowered position to about 3.54 inches (90 mm) from the ground in the raised position. In certain embodiments, the cutting height varies from about 0.78 inches (20 mm) from the ground in the lowered position to about 2.36 inches (60 mm) from the ground in the raised position.

Height adjustment mechanism 290 also includes an interface 300 with a nesting ramp 302 (which may also be referred to herein as a nesting telescoping ramp 302, or telescoping ramp 302). Manual actuator 292 is operably coupled to nesting ramp 302. In the illustrated embodiment, the manual actuator 292 is rotatable about an axis C that coincides with the axis of rotation a. Thus, in the illustrated embodiment, the axis C also defines the axial direction B. However, in other embodiments, the axis C and the axis of rotation a need not coincide and may be offset (parallel) or transverse to each other. The nesting ramp 302 may be described below with respect to an axial direction that primarily refers to the direction of axis C, but may also refer to axis direction B when axial direction B is the same as the axial direction of axis C.

The nesting ramps 302 are movable relative to one another between a retracted position (shown in fig. 7 and 14) and an extended position (shown in fig. 9 and 16). An intermediate position (shown in fig. 8 and 15) is defined between the retracted position and the extended position. In the retracted position, the blade 34 (or other implement) is fully raised. In the extended position, the blade 34 (or other implement) is fully lowered. In the neutral position, the blade 34 (or other implement) is between a fully raised position and a fully lowered position. In the illustrated embodiment, the fully raised position of the blade 34 corresponds to a longer grass setting and the fully lowered position of the blade 34 corresponds to a shorter grass setting.

The nesting ramp 302 includes 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 embodiment, the nesting ramp 302 includes a first ramp 304, a second ramp 306, a third ramp 308, a fourth ramp 310, and a fifth ramp 312. The manual actuator 292 is operably coupled to the first ramp 304 such that rotation of the manual actuator 292 about the axis C causes the first ramp 304 to rotate about the axis C. The manual actuator 292 is directly coupled to the first ramp 304; however, in other embodiments, the manual actuator 292 may be indirectly coupled to the first ramp 304, or may be directly or indirectly coupled to any other nesting ramp 302.

The first ramp 304 may be mounted relative to the platform 14 for rotation about the axis C and fixed relative to the platform 14 in the axial direction of the axis C. In some embodiments, manual actuator 292 may be mounted relative to platform 14 for rotation about axis C and fixed relative to the platform in the axial direction of axis C; further, the first ramp 304 may be fixedly mounted to the manual actuator 292 for movement therewith.

Referring to fig. 11, the first ramp 304 and the second ramp 306 are shown exploded from one another. The first ramp 304 includes an annular portion 314 and a helical projection 316 having a helical surface 317. The annular portion 314 is annular about the axis C. The helical projection 316 projects radially from an outer cylindrical surface 318 of the annular portion 314. The outer cylindrical surface 318 defines a first radial distance R1 (fig. 17) and a second radial distance R2 (fig. 17) at its furthest distance from the axis C by the helical projection 316. The helical projection 316 extends radially from a radial distance R1 to a radial distance R2. The helical projection 316 extends circumferentially about the axis C through an arc angle D (fig. 12 and 17) of about 70 degrees. In the context of degrees, "about" is understood to mean +/-10 degrees. In other embodiments, arc angle D may be between about 20 degrees and about 120 degrees, or between about 30 degrees and about 310 degrees, or between about 40 degrees and about 100 degrees, or between about 50 degrees and about 90 degrees, or between about 60 degrees and about 80 degrees. The helical projection 316 is also inclined in the axial direction of the axis C. The helical projection 316 may have an angular pitch of about 182.9 degrees per inch (7.2 degrees per millimeter). In some embodiments, the angular pitch may be between about 160 degrees per inch and about 200 degrees per inch (between about 6.3 degrees per millimeter and about 7.9 degrees per millimeter). In some embodiments, the angular pitch may be between about 100 degrees per inch and about 254 degrees per inch (between about 4 degrees per millimeter and about 10 degrees per millimeter). In the context of angular pitch, "about" is understood to mean +/-10 degrees per inch.

The first ramp 304 also includes a follower 320 that projects from the outer cylindrical surface 318 and has 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. The normal to the deployment stop surface 324 projects in a first direction 328 of rotation of the nesting ramp 302 about axis C, while the normal to the retraction stop surface 326 projects in a second direction 330 of rotation of the nesting ramp 302 about axis C. The second direction of rotation 330 is opposite the first direction of rotation 328.

With continued reference to fig. 11, the second ramp 306 is mounted for rotation about axis C and movement in the axial direction of axis C. The second ramp 306 includes an annular portion 334 and a helical protrusion 336. Annular portion 334 is annular about axis C and extends radially from inner cylindrical surface 335 to outer cylindrical surface 338. The inner cylindrical surface 335 is disposed substantially at a first radial distance R1 and the outer cylindrical surface 338 is disposed substantially at a second radial distance R2. Helical protrusion 336 protrudes radially from an outer cylindrical surface 338 of annular portion 334. The helical projection 136 includes a helical surface 337. A third radial distance R3 (fig. 12 and 17) is defined by helical projection 336 at its furthest distance from axis C. Helical protrusion 336 and follower 340 extend radially from radial distance R2 to radial distance R3, as best shown in fig. 12. Helical protrusion 336 extends circumferentially about axis C through arc angle D (fig. 12 and 17). The helical protrusion 336 is also inclined in the axial direction of the axis C (fig. 11), and may have the same pitch as the helical protrusion 316 described above.

The second ramp 306 also includes a follower 340 that projects from the outer cylindrical surface 338 and has 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. The normal to the deployment stop surface 344 projects in a first direction 328 of rotation about axis C, while the normal to the retraction stop surface 146 projects in a second direction 330 of rotation about axis C.

Fig. 12 and 13 illustrate a second ramp 306. As best shown in fig. 13, the second ramp 306 defines a helical track 348 (which may also be referred to herein as a helical surface 348). The helical track 348 extends radially from a radial distance R1 to a radial distance R2 between the inner and outer cylindrical surfaces 335, 338, as best shown in fig. 12. Spiral track 348 extends circumferentially about axis C through about arc angle D and is circumferentially bounded by deployment stop 350 and retraction stop 352. The helical track 348 is configured to engage the follower 320. The follower 320 is configured to move along the helical track 348 between a deployment stop 350 and a retraction stop 352. The deployment stop 350 is configured to engage the deployment stop surface 324. The retraction stop 352 is configured to engage the retraction stop surface 126. The helical track 148 may have the same angular pitch as the helical projection 316 described above.

The third ramp 308, fourth ramp 310 and fifth ramp 312 each have all the same features as the second ramp 306 described above and shown in fig. 11-13. As such, similar features of third ramp 308, fourth ramp 310, and fifth ramp 312 may be labeled in the figures with the same reference numerals used to describe corresponding features of second ramp 306, with the addition of a "'", a "" ", and a" "" "to similar features of third ramp 308, fourth ramp 310, and fifth ramp 312. Reference is made to the description of the second ramp 306 in order to describe the features of the third ramp 308, the fourth ramp 310 and the fifth ramp 312 so that a repeated description is not necessary herein. The only difference is that each of the third ramp 308, fourth ramp 310, and fifth ramp 312 progresses with increasing radial dimensions to allow nesting.

Specifically, as illustrated in fig. 17 (and with reference to the illustrated reference numerals of fig. 11-13), the inner cylindrical surface 335 'of the third ramp 308 is disposed generally at a radial distance R2, and the outer cylindrical surface 338' of the third ramp 308 is disposed generally at a radial distance R3. The helical track 348', the deployment stop 350', and the retraction stop 352' of the third ramp 308 extend radially between the inner and outer cylindrical surfaces 335', 338' generally from the radial distance R2 to the radial distance R3. The helical protrusion 336 'and follower 340' of the third ramp 308 extend radially from a generally radial distance R3 to a radial distance R4.

The inner cylindrical surface 335 "of the fourth ramp 310 is disposed substantially at a radial distance R3 and the outer cylindrical surface 338" of the fourth ramp 310 is disposed substantially at a 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 "generally from the radial distance R3 to the radial distance R4.

The helical protrusion 336 "and the follower 340" of the fourth ramp 310 extend radially from a generally radial distance R4 to a radial distance R5.

The inner cylindrical surface 335 '"of the fifth ramp 312 is disposed substantially at a radial distance R4 and the outer cylindrical surface 338'" of the fifth ramp 312 is disposed substantially at a 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 cylindrical surface 335 '" and the outer cylindrical surface 338 ' "generally from a radial distance R4 to a radial distance R5. The helical projection 336 '"and the follower 340'" of the fifth ramp 312 extend radially from a generally radial distance R5 to a radial distance R6. In some embodiments, helical protrusion 336 '"and follower 340'" may be omitted from fifth ramp 312 (last ramp).

In the context of radial distances R1-R6, "generally" is understood to mean that within the tolerance that allows nesting of the nesting ramps 302, e.g., fitting one within the other in a progressive manner. The gap between adjacent nesting ramps 302 is nominal.

The radial distance R6 is greater than the radial distance R5; the radial distance R5 is greater than the radial distance R4; the radial distance R4 is greater than the radial distance R3; the radial distance R3 is greater than the radial distance R2; the radial distance R2 is greater than the radial distance R1. In the illustrated embodiment, 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 embodiments, 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 incrementally greater than the previous radial distances of about 0.05 inches to about 0.3 inches (1.27 mm to 7.62 mm). In other embodiments, the radial distance R1 may be between about 1.0 inch (54.4 mm) and about 4.0 inches (101.6 mm), with the remaining radial distances R2-R6 incrementally greater than the previous radial distances of about 0.05 inches to about 0.3 inches (1.27 mm to 7.62 mm). In the context of radial distance, "about" is understood to mean +/-0.1 inches.

Fifth ramp 312 (or the furthest end of nesting ramp 302 if a different number of ramps are employed) may be directly and fixedly coupled to guard 40. In other embodiments, fifth ramp 312 may be coupled indirectly to guard 40 and/or may be coupled directly or indirectly to other components of blade module 28, such as blade support 46. The motor 36 may be fixed to and supported by the guard 40, which may include some degree of movement or damping to accommodate vibrations, external forces, etc., or may be rigidly fixed. The motor 36 is disposed in a receptacle 354 defined by the nesting ramp 302, which can save space, particularly in the axial direction of the axis C.

The second ramp 306 is suspended from the first ramp 304 (e.g., by gravity). Further, a third ramp 308 depends from the second ramp 306. Further, a fourth ramp 310 depends from the third ramp 308. Further, a fifth ramp 312 depends from the fourth ramp 310. Further, the guard 40 is suspended from the fifth ramp 312. Further, the guard 40 supports the motor 36, and in turn, the motor 36 drives the vane support 46 and the vane(s) 34.

The height adjustment mechanism 290 may include one or more resilient members (not shown), such as damping members (e.g., foam, rubber, elastomeric material, tape, etc.), 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, etc., to prevent the nesting ramps 302 from separating from one another. The height adjustment mechanism 290 may include one or more friction members (not shown) to prevent 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 ramp 302 or may be integrally formed with the nesting ramp 302 to provide an engagement friction surface therebetween. The resilient member and/or friction member may be disposed in the helical track 348, 348', 348", 348'", or any other location, such as in the receptacle 354 or external to the nesting ramp 302. Friction between the nesting ramps 302 themselves may prevent the nesting ramps 302 from separating from each other in the axial direction of axis C. In any event, the arrangement of the resilient/damping/biasing/friction members and/or the nesting ramp 302 may allow a degree of movement or damping to accommodate vibrations, external forces, and the like. For example, when the blade 34, blade support 46, or guard 40 strike a hard object, a degree of movement or damping may allow the cutting module 30 to move elastically or be damped.

In the illustrated embodiment, the fifth ramp 312, motor 36, drive shaft 38, guard 40, vane support 46, and vane 34 move together as a unit in the direction of 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 about 1.5 inches (38 mm) or more in the axial direction of the axis C in response to an angular range of 180 degrees of rotation of the manual actuator 292. In other embodiments, the vane 34 may be displaced about 1.57 inches (40 mm) or more in the axial direction of the axis C in response to 180 degrees of rotation of the manual actuator 292.

In some embodiments, the first ramp 304 may be driven by a servo motor (not shown). In this embodiment, the manual actuator 292 need not be employed, and the height adjustment mechanism 290 is electronically controlled by the servo motor via the controller 200.

In operation, blade height adjustment may be accomplished manually by an operator or electronically by a servo motor. For manual adjustment, the operator engages the gripping 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 embodiment). The operator rotates the manual actuator 292 in a first direction 328 (e.g., clockwise) to lower the blade 34 (or other implement) and rotates the manual actuator in a second direction 330 (e.g., counter-clockwise) to raise the blade 34 (or other implement). Fig. 7 and 14 illustrate the height adjustment mechanism 290 in a retracted position corresponding to the fully raised blade 34. When the manual actuator 292 rotates in the first direction 328, the first ramp 304 begins to rotate. As the first ramp 304 begins to rotate, the follower 320 moves along the helical track 348 of the next immediately adjacent ramp, in this case the second ramp 306. The follower surface 322 engages the helical track 348 and urges the second ramp 306 downward (away from the first ramp 304, toward the extended position) in the axial direction of the axis C until the deployment stop surface 324 engages the deployment stop 350. The third, fourth, and fifth ramps 308, 310, 312, and the blade 34 (and any other components configured to move as described above) move with the second ramp 306 in the axial direction of the axis C. Continued rotation of the first ramp 304 then causes the second ramp 306 to begin to rotate about axis C in fixed relation to the first ramp 304 due to engagement between the deployment stop surface 324 and the deployment stop 350. The follower 340 now follows the spiral track 348' of the next immediately adjacent ramp, in this case the third ramp 308. The follower surface 342 engages the helical track 348 'and urges the third ramp 308 downward (away from the first and second ramps 304, 306, toward the extended position) in the axial direction of the axis C until the deployment stop surface 344 engages the deployment stop 350' (as illustrated in the intermediate position shown in fig. 8 and 15). The fourth and fifth ramps 310, 312 and the blade 34 (and any other components configured to move as described above) move with the third ramp 308 in the axial direction of the axis C. Continued rotation of the first ramp 304 and the second ramp 306 then causes the third ramp 308 to begin to rotate about axis C in a fixed relationship with the first ramp 304 and the second ramp 306 due to the engagement between the expansion stop surface 344 and the expansion stop 350'. The follower 340' now moves along the helical track 348 "of the next immediately adjacent ramp, in this case the fourth ramp 310, and the above process is repeated until the fourth ramp 310 and the fifth ramp 312 are also deployed toward the extended position, thereby lowering the blade 34 to the fully lowered position (as illustrated by the extended position shown in fig. 9 and 16). Thus, the axially extending movement is sequentially transferred to adjacent ones of the second, third, fourth, and fifth ramps 306, 308, 310-312 (one at a time in adjacent order). Thus, the nesting ramp 302 is telescoping.

To return the blade 34 toward 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 the reverse order. Initially, the first ramp 304 rotates with the second ramp 306, the third ramp 308, and the fourth ramp 310 as a unit. 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 axis C, and continued rotation of the first ramp 304 now causes only the second ramp 306 and the third ramp 308 to rotate. This process continues until the nesting ramp 302 returns to the retracted position and the blade 34 is fully raised. Thus, the axial retraction movement is sequentially transferred to adjacent ramps (one after the other in adjacent order) of the fifth ramp 312, the fourth ramp 310, the third ramp 308 to the second ramp 306 and one at a time.

Accordingly, in one aspect, the present disclosure provides a robotic garden tool, comprising: a platform; an implement coupled to the platform; a motor configured to drive an appliance; and a height adjustment mechanism configured to control movement of the implement relative to the platform independent of actuation of the implement, the height adjustment mechanism comprising a nesting ramp.

The robotic garden tool according to any aspect, wherein the nesting ramp is movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement relative to the platform, and the extended position corresponds to a second position of the implement relative to the platform, wherein the first position is different from the second position.

The robotic garden tool according to 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 according to any aspect, wherein the nesting ramp comprises at least a first ramp and a second ramp, the first ramp comprising a first helical surface and the second ramp comprising a second helical surface.

The robotic garden tool according to any aspect, wherein the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement relative to the platform, and the extended position corresponds to a second position of the implement relative to the platform, wherein the first position is different from the second position.

The robotic garden tool according to any aspect, wherein each of the first ramp and the second ramp 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 relative to the second ramp.

The robotic garden tool according to any aspect, wherein the nesting ramp comprises at least a first ramp and a second ramp, the first ramp and the second ramp being rotatable about an axis, wherein a first radius defined from the axis to the first ramp is less 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 according to any aspect, wherein the first ramp is configured to nest in the second ramp in the retracted position.

The robotic garden tool according to any aspect, wherein the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position.

In another aspect, the present disclosure provides a cutting module for a robotic garden tool, comprising: a motor configured to drive an appliance; and a height adjustment mechanism configured to move the implement independent of the drive of the implement, the height adjustment mechanism comprising a nesting ramp.

The cutting module of any aspect, wherein the nesting ramp is movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement and the extended position corresponds to 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 ramp comprises 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 ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the implement and the extended position corresponds to 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 ramp and the second ramp is rotatable about an axis, wherein a first radius defined from the axis to the first helical surface is less than a second radius defined from the axis to the second helical surface to allow nesting of the first ramp relative to the second ramp.

The cutting module of any aspect, wherein the nesting ramp comprises at least a first ramp and a second ramp, the first ramp and the second ramp rotatable about an axis, wherein a first radius defined from the axis to the first ramp is less than a second radius defined from the axis to the second ramp to allow nesting of the first ramp relative to the second ramp.

The cutting module of any aspect, wherein the first ramp is configured to nest in the second ramp in the retracted position.

The cutting module of any aspect, wherein the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position.

In yet another aspect, the present disclosure provides a robotic lawnmower comprising: a platform; a blade configured to move relative to the platform; a motor configured to rotate the blade about an axis of rotation, wherein the rotation is independent of movement relative to the platform; and a height adjustment mechanism configured to control movement of the blade relative to the platform, the height adjustment mechanism comprising a nesting ramp.

The robotic lawnmower of any aspect, wherein the nesting ramp comprises at least a first ramp and a second ramp, wherein each of the first ramp and the second ramp is rotatable about an axis, wherein the first ramp and the second ramp are movable relative to each other between a retracted position and an extended position, and wherein the retracted position corresponds to a first position of the blade and the extended position corresponds to a second position of the blade, wherein the first position is different than the second position.

The robotic lawn trimmer may additionally or alternatively include any aspect of any cutting module and/or any robotic garden tool disclosed herein in any combination.

Thus, the present disclosure provides, among other things, a garden tool 12, such as an autonomous lawn mower, having blade height adjustment using a nesting ramp 302.

Claims

1. A robotic garden tool, comprising:

a platform;

an implement movably coupled to the platform;

a motor configured to drive the appliance; and

a height adjustment mechanism configured to control movement of the implement relative to the platform, the height adjustment mechanism comprising an interface that engages gear teeth.

2. The robotic garden tool of claim 1, wherein the interface of meshing gear teeth comprises 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.

3. The robotic garden tool of claim 2, wherein the first set of gear teeth is configured to be manually actuated to effect movement of the second set of gear teeth.

4. The robotic garden tool of claim 2, wherein the second set of gear teeth is configured to be driven by a servo motor.

5. The robotic garden tool of claim 1, wherein the height adjustment mechanism further comprises a manual actuator configured to move in response to manual actuation of an operator, wherein the implement is configured to move relative to the platform in response to manual actuation of the manual actuator.

6. The robotic garden tool of claim 1, wherein the interface of meshing gear teeth comprises a helical rack and a bevel gear.

7. The robotic garden tool of claim 6, wherein the helical rack defines a central axis and is configured to rotate about the central axis.

8. The robotic garden tool of claim 7, wherein the bevel gear is biased into engagement with the helical rack and configured to move at least axially relative to the central axis.

9. The robotic garden tool of claim 8, wherein the implement is configured to move at least axially in response to axial movement of the bevel gear.

10. The robotic garden tool of claim 6, wherein the height adjustment mechanism further comprises a servo motor configured to drive the bevel gear or the helical rack.

11. The robotic garden tool of claim 1, wherein the interface of meshing gear teeth comprises a linear rack and a circular gear.

12. The robotic garden tool of claim 11, wherein the circular gear is configured to be manually actuated to effect movement of the linear rack.

13. The robotic garden tool of claim 11, wherein the height adjustment mechanism further comprises a servo motor configured to drive the linear rack or the circular gear.

14. The robotic garden tool of claim 1, wherein rotation of at least a portion of the interface about a central axis causes the implement to move by at least 0.75 inches per 90 degrees of rotation.

15. A cutting module for robotic garden tools, comprising:

a motor configured to drive an appliance; and

a height adjustment mechanism configured to move the implement independent of actuation of the implement, the height adjustment mechanism including an interface that engages gear teeth.

16. The cutting module of claim 15, wherein the interface of meshing gear teeth comprises 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.

17. The cutting module of claim 16, wherein the first set of gear teeth is configured to be manually actuated to effect movement of the second set of gear teeth.

18. The cutting module of claim 16, wherein the second set of gear teeth is configured to be driven by a servo motor.

19. The cutting module of claim 15, wherein the interface of meshing gear teeth comprises a helical rack and bevel gear interface or a linear rack and circular gear interface.

20. A robotic lawnmower comprising:

a platform;

a blade configured to move relative to the platform;

a motor configured to rotate the blade about an axis of rotation, wherein the rotation is independent of movement relative to the platform; and

a height adjustment mechanism configured to control movement of the blade relative to the platform, the height adjustment mechanism including an interface that engages the gear.