Patent Application
20160353659
The present disclosure is directed to a lawn maintenance tool configured to perform a grass cutting function utilizing a reduced amount of energy than a typical tool.
Typical walk-behind lawn mowers and riding mowers utilize an engine or other power supply to rotate one or more mower blades. The mower blades are typically formed by stamping a thick metal sheet in order to form an elongated metal blade. These thick, heavy blades rotate at high speeds, which requires significant torque to maintain such high rotational speeds of the blade(s). As a result, large engines—typically in the form of a combustion engine—are attached to a mower deck or a mower frame, and these large engines are needed to produce the high torque requirements for rotating the heavy blades. The engines are often quite loud, requiring hearing protection during operation of the mowers.
According to one aspect of the present disclosure, a high-efficiency lawn maintenance tool includes a frame and a deck attached to the frame. The high-efficiency lawn maintenance tool also includes a plurality of ground engaging members attached to the frame. The high-efficiency lawn maintenance tool further includes a power source attached to one of the frame and the deck, wherein the power source is connected to a drive shaft that passes through the deck. The high-efficiency lawn maintenance tool still further includes a high-efficiency blade system attached to the drive shaft. The high-efficiency lawn maintenance tool also includes a controller electrically connected to the power source, wherein the controller is configured to correlate the load and/or the mower groundspeed independent of an operator's control.
Advantages of the present disclosure will become more apparent to those skilled in the art from the following description of the embodiments of the disclosure which have been shown and described by way of illustration. As will be realized, the disclosed apparatus are capable of other and different embodiments, and their details are capable of modification in various respects.
These and other features of the present disclosure, and their advantages, are illustrated specifically in embodiments of the disclosure now to be described, by way of example, with reference to the accompanying diagrammatic drawings, in which:
It should be noted that all the drawings are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these figures have been shown exaggerated or reduced in size for the sake of clarity and convenience in the drawings. The same reference numbers are generally used to refer to corresponding or similar features in the different embodiments. Accordingly, the drawing(s) and description are to be regarded as illustrative in nature and not as restrictive.
For the purposes of this disclosure, the term low-energy is used interchangeably with the term “high-efficiency.”
Referring to
The high-efficiency lawn maintenance tool 20 includes ground engaging members 26 attached to the frame 24. Any suitable ground engaging member 26 can be used with the described lawn maintenance tool 20 including, but not limited to, pneumatic tires, non-pneumatic tires/wheels, track assemblies, and wheels with built-in suspension features. As shown in
The high-efficiency lawn maintenance tool 20 includes a deck 28. The deck 28 can include various parts including a deck shell 30. Use of the below described mower blade assembly enables the deck shell 30 and the deck 28 to be of relatively short vertical height when compared to many known walk-behind mower decks. This lessened height requirement, or “low profile” deck, can provide benefits such as minimized storage volume requirements, minimized shipping volume requirements and the like. The deck shell 30 can be constructed of any suitable material.
The high-efficiency lawn maintenance tool 20 includes a power source 34 configured to provide rotational power to a cutting blade system. In the illustrated embodiment, the power source 34 is a battery-powered electric motor, but it should be understood by one having ordinary skill in the art that the power source 34 may also be an internal combustion engine, a hybrid-electric motor, or any other power source capable of providing a rotational power output. The power source 34 is mounted to one of or both the frame 24 and the deck 28, and the power source 34 includes a drive shaft 36 extending through the frame 24 and the deck 28.
The illustrated exemplary embodiment of high-efficiency lawn maintenance tool 20 includes a user-operated handle 38 connected to the frame 24 and/or the deck 28. In one example, the collapsible handle is “U”-shaped, with the ends of the U being mounted to the handle mounts and the closed portion of the U serving as a handle for an operator to push or otherwise control the high-efficiency lawn maintenance tool 20. The collapsible handle can include any number of ergonomic designs to ease operator interaction. In another example, the handle 38 can comprise a “J”-shape that connects to the frame 24 on only one side. Of course, other shapes of handle 38 are also contemplated.
In one example, the collapsible handle 38 can be rotated at the handle mounts to facilitate folding the collapsible handle 38. Furthermore, the collapsible handle 38 can include a hinged portion at approximately one-half of the length of the collapsible handle 38 such that the collapsible handle 38 can be folded onto itself and lie flat on the deck 28 and/or the frame 24.
In another example, the collapsible handle 38 can also be attached to a damping cylinder. The damping cylinder can, when actuated, raise a portion of the collapsible handle 38 at a controlled rate from a collapsed position to an extended position. The damping cylinder can be mounted to the collapsible handle 38 and to the frame 24.
The combination of the low-profile deck 28 previously described and the collapsible handle 38 enable reduced shipping volume requirements compared to typical walk-behind mowers. In one example, the walk behind mower embodiment of the high-efficiency lawn maintenance tool 20 can be shipped in a box having less than one-half of the height of a typical walk-behind mower. In a more particular example, the shipping box height can be between one-half and one-third the height of a typical walk-behind mower. In yet another example, the shipping box may be described as having dimensions approximating the dimensional proportions of a pizza box, that is, the height of the shipping box is significantly less than the length or width of the shipping box.
The handle 38 can be folded toward the frame 24 for storage and/or shipping purposes. Turning to
As shown in
The shell 50 is a generally flexible or semi-rigid member that forms a physical barrier between the deck 28 and the cutting blades 56 as well as the cut grass, as shown in
As shown in
The biasing member 70 is configured as a generally L-shaped spring, as shown in
The biasing member 70 is attached to the mounting plate 54 in a cantilevered manner, wherein the distal end of the biasing member 70—defined by the base 74—is attached to the mounting plate 54 and the remainder of the biasing member 70 extends therefrom. The illustrated embodiment shows the base 74 as having two (2) attachment mechanisms 84 for attachment to the mounting plate 54, but it should be understood by one having ordinary skill in the art that the mounting plate 54 may include any number of attachment mechanisms 58. The base 74 is attached to the surface of the mounting plate 54 and extends through a corresponding opening of the mounting plate 54 such that the body 76, curved portion 78, and bearing portion 80 are generally positioned below a downward facing lower surface of the mounting plate 54.
The body 76 of the biasing member 70 of each quick-attach mechanism 58 extends from the base 74 at an angle, as shown in
In an embodiment, a cap 86 of the quick-attach mechanism 84 extends downwardly from the downward facing lower surface of the mounting plate 54, as shown in
As shown in
In operation, the cutting blades 56 are operatively connected to the blade system 48 by way of the quick-attach mechanism 58. The cutting blade 56 is first positioned adjacent to the cap 86 of the quick-attach mechanism 58 such that the aperture 100 of the cutting blade is aligned with the cap 86. The cutting blade 56 is then pushed toward the mounting plate 54, wherein the cap 86 of the quick-attach mechanism 58 is received in the aperture 100 of the cutting blade 56. Further, the mounting portion 94 of the cutting blade 56 contacts the body 76 and curved portion 78 of the biasing member 70, and as the cutting blade 56 is moved toward the mounting plate 54, the biasing member 70 is actuated by bending and rotating in a cantilevered manner. If the cutting blade 56 is not fully attached to the cap 86, the biasing member 70 biases the cutting blade 56 away from the mounting plate 54 such that the cutting blade 56 is disengaged from the cap 86. As the biasing member 70 is actuated, the bearing portion 80 extends through the corresponding slot 66 of the shell 50. Once the cutting blade 56 has been pushed until it is flush with the mounting plate 54, the cutting blade 56 is then pulled radially toward the radial edge 68 of the shell 50 until the post 88 of the cap 86 contacts the end of the elongated aperture 100 formed through the cutting blade 56. As the cutting blade 56 slides radially outward, the mounting portion 94 of the cutting blade 56 slides along the body 76 and curved portion 78 of the biasing member 70 after which the distal end of the cutting blade 56 slides along the bearing surface (downward facing surface) of the bearing portion 80. In this position, the cutting blade 56 is positively attached to the quick-attach mechanism 58 extending from the mounting plate 54, and the spring bias generated at the curved portion 78 of the biasing member 70 continually pushes radially against the edge at distal end of the cutting blade 56. This radial bias from the biasing surface against the cutting blade 56 ensures continuous attachment between the cutting blade 56 and the mounting plate 54. This radial bias also prevents accidental disconnection of the cutting blade 56 by preventing the cutting blade from 56 sliding radially toward the central aperture 64 of the mounting plate 54. The mounting portion 94 of the cutting blade 56 is sandwiched between a portion of the cap 86 and the mounting plate 54 to reduce or eliminate any “bounce” at the distal end of the tip portion 98.
The cutting blade 56 is removed by actuating—or pressing—the biasing member 70 toward the mounting plate 54, thereby removing the radial bearing force applied to the cutting blade 56 and effectively disengaging the cutting blade 56 from the biasing member 70. The cutting blade 56 is then slid radially inward toward the central aperture 64 of the mounting plate 54 until the entire plate 90 of the cap 86 is aligned with the aperture 100 of the cutting blade 56. At this point, the cutting blade 56 can be removed from the quick-attach mechanism 58.
As noted previously, the quick-attach mechanism 58 allows the cutting blades 56 to be releasably attachable to the mounting plate 54 without the use of any handheld tools or other tool separate from the blade system 48.
The described high-efficiency blade system 48 is further described in U.S. Patent Application having Ser. No. 62/325,159 and related applications. It is to be understood that other, similar systems can also be used such as the blade system in described in U.S. Patent Application having Ser. No. 15/166,378 and related applications.
It is to be understood that the design of the high-efficiency blade system 48 can be scalable to larger or smaller needs. For example, a larger walk-behind mower may require a larger blade system 48, or even a plurality of smaller blade assemblies 48, as shown in
When scaling the design for larger or smaller blade systems 48, a mathematical relationship between the optimal number of blades and the diameter of the blade system 48 can be calculated. The mathematical relationship can include a minimum of ten (10) blade passes per foot at a minimum. This relationship may also place a maximum 19,000 feet per minute (fpm) cutting blade tip speed on the blade system 48. In one example, a desired cutting blade speed 56 can be about 10,000 fpm. In another example, the high-efficiency blade assembly 48 can operate at about 2,200 rpm with a projected 12,000 foot per minute (fpm) blade tip speed. This is a significant reduction from a standard 21-inch diameter system that may operate at 3,200 rpm and have a 19,000 fpm blade tip speed.
In the shown examples of
In another example of the walk-behind mower, the lawn maintenance tool 20 can include a trailing shield for several purposes. One such purpose is to prevent undesirable debris from being propelled toward the operator. Another purpose is to urge grass clippings to lie flat as the trailing shield passes over the grass clippings. Yet another purpose is to “comb” the grass clippings and the uncut grass as the trailing shield passes over them. In this example, the trailing shield can include a number of teeth or channels that can comb the grass.
In one example, the high-efficiency lawn maintenance tool 20 includes a brush 110 (best seen in the underside view of
As shown in
One example bagging attachment 114 is supported on both sides by a brace 118. A rear end of the brace 118 can be attached at the rear of the bagging attachment 114, while a front end of the brace 118 extends past the front of the bagging attachment 114. The front end of the brace 118 includes structure configured to attach the brace 118 to corresponding structure on the collapsible handle 38 or some other portion of the frame 24 and/or deck 28.
The brace 118 defines an aperture 120 somewhere between the rear end and the front end of the brace 118. A shaft 124 passes through the apertures of the brace 118 on each side of the bagging attachment 114. The terminal ends of the shaft 124 include rollers 126 which rest on the ground engaging members 26 at the rear of the lawn maintenance tool 20. When the lawn maintenance tool 20 traverses along a driven surface (e.g., a yard), the ground engaging members 26, through friction, urge the rollers 126 and the shaft 124 to rotate. The brush 110 or a similar structure is attached to the shaft 124 and is located generally within a case 128. As the walk-behind mower moves along, the ground engaging members 26 rotate, which in turn rotates the rollers 126 and the shaft 124, which rotates the brush 110. The rotating brush 110 urges grass clippings lying on the driven surface to elevate and be placed into the bagging attachment 114 behind the case 128. In one example, the bagging attachment 114 can be a drawstring bag designed to attach to the case 128 and collect grass clippings. As the bag becomes full, the operator can remove the drawstring bag from the case 322 and simply pull the string to close the bag. It is to be understood that the grass clipping bagging attachment 114 is not necessarily present in order to use the high-efficiency lawn maintenance tool 20, but may be attached and removed as the operator sees fit.
In another example of the high-efficiency lawn maintenance tool 20, such as a walk-behind mower equipped with a sweeper for collection of grass clippings, another attachment system can be used. Turning to
Continuing with
Yet another sweeper mounting arrangement is shown in
The sweeper is easily driven by attaching a gear to the wheel shaft, with a mating gear on the sweeper. This rotates the sweeper in the proper direction for best function. Unfortunately, since the wheels move up and down in relation to the deck to accommodate different cutting heights, the deck drive must also be able to accommodate that motion.
To solve this problem, the sweeper gear 150 is mounted on the end of a pivot arm 154 which is spring loaded to assure gear engagement. The pivot point 156 of the pivot arm 154 is coincident with the sweeper shaft 124, enabling rotation about the sweeper shaft 124 in directions represented by arrow 158. The sweeper gear 150 also has a cogged belt sprocket 160. This cogged belt sprocket 160 is matched by a sprocket 164 on the sweeper shaft 124. Related and proportional motion between the sprockets 160, 164 is accomplished via a cogged belt 166.
In this configuration, when the mower 20 is pushed (or driven) a rear wheel gear 168 attached to a rear wheel shaft drives the sweeper gear 150 which in turn drives the sweeper shaft 124 via the sprockets 160, 164.
A problem arises when performing a common pivot turn on the inside wheel with the mower. If the sweeper drive is on the inside wheel (which does not rotate in a pivot turn), the sweeper stops functioning in a pivot turn. To address this, another drive system (the mirror of the first) is attached to the opposite side of the sweeper shaft 124 which likewise engages an identical gear on the other rear wheel of the mower 20. This is best seen in
In one example, the sprockets 164 on the sweeper shaft 124 are equipped with a one-way clutch or bearing. This allows either sprocket 164 to engage the shaft 124 when the mower is moving forward. But when one sprocket 164 slows down (as in a turn) or reverses, it no longer engages the shaft 124 and spins freely. As such, the outside and faster wheel will always determine the speed of the sweeper brush 110.
In the shown example, the one-way bearing/clutch is accomplished with a sliding pin/internal cam design used on the drive system of some known front wheel drive mowers.
In another example, the brush 110 can be powered by the power source 34 located on the deck 28. Furthermore, structure for taking power from the power source 34 and rotating the brush 110 can be an after-market feature sold as a snap-in place upgrade.
In another example, the walk-behind mower example of the lawn maintenance tool 20 can be self-propelled by using the power source 34 located on the deck 28. In yet another example, the self-propelled feature can be an after-market kit. The after-market kit can include the structure necessary to add the self-propelled feature, higher capacity batteries (for battery-powered lawn maintenance tools 20), and a controller. The controller can include software that senses the load on the drive shaft 36 and then adjusts the ground speed of the walk-behind mower to optimize the cut of the grass. In one example, the grass clipping bagging attachment 114 can be included in the kit as well.
The self-propelled lawn mower example can use either a differential or a straight drive system. At least one of the ground engaging members 26 or its associated structure can include a one-way drive, or over-running clutch.
In another embodiment, the high-efficiency maintenance tool 20 comprises a handheld implement such as a typical string trimmer. In this example, a guard can be placed around the exterior of a trimmer shell such that the cutting blades 56 cannot contact a relatively strong stationary object such as a fence post, tree trunk, building foundation, etc. while trimming grass.
For the high-efficiency lawn maintenance tools described, the battery-operated versions can be charged in various ways. In particular, the walk-behind lawn mower high-efficiency lawn maintenance tools 20 will be discussed. In one example, the rechargeable batteries 46 can be simply removed from their docking stations on the deck 28 and charged at a location convenient to the operator. In another example, a power cord 170 can be provided to be plugged into a typical wall outlet 174 for 110-volt or other standard electrical supply in order to charge the battery(ies). The other end of the power cord 170 can be plugged into a charging receptacle on the high-efficiency lawn maintenance tool 20.
As shown in
As shown in
Returning to
In a separate example, it may be beneficial to require the operator to remove the rechargeable batteries 46 from the mower frame 24 and/or deck 28 prior to folding the collapsible handle 38 onto the deck 28.
The described apparatus can have numerous benefits. The blade system 48 can be significantly quieter than typical mower blades when in operation. In some instances, it may be desirable to add a feature to the high-efficiency lawn maintenance tools 20 to alert the operator that the tool 20 is in operation and the blade system 48 may be rotating. Some examples of alerts can include lights, physical movement of an additional structure, or creation of an artificial sound.
The high-efficiency walk-behind lawn mower described herein enables a relatively low-weight mower and shipping box combination that enables shipping by typical standard carriers such as UPS, FedEx, etc. without incurring additional charges based upon weight overages. The same can be said of the dimensions of the high efficiency walk-behind lawn mower; it enables shipping via standard carriers without incurring additional charges based upon total dimensional overages.
The high-efficiency lawn maintenance tool 20 also has a relatively high efficiency thereby enabling: increased run-time of the battery, lower cost to operate, or both.
The described apparatus further enables a high-efficiency method of collecting the grass clippings via rotating brush. Another feature of the disclosure is the skeletal frame of the high-efficiency walk behind lawn mower from which all other features are attached. In contrast, many existing walk-behind mowers have a stamped metal or formed plastic deck that is used as the frame of the lawn care device.
As described above, the individual grass cutting blades on the blade system 48 can be considered quick-change, or tool-less for installation and removal. Furthermore, the wheels of the mower can be “fast attach” wheels that can be removed for shipping. In another example, the wheels remain on the frame 24 for shipping, and serve as weight bearing structure within a shipping box to enable reliable stacking of the mowers within shipping boxes.
The disclosed lawn maintenance tool 20 also enables a control system that has an infinitely variable motor speed by analyzing the load on the rotating blade system 48 or on the deck 28 itself to vary the power to the power source 34 (e.g., an electric motor). For example, if the control system senses a small load, e.g., from short dry grass cutting operations, the controller will slow the motor. This method can correlate the load and/or the mower groundspeed independent of the operator's control. In another example, the controller can vary both the speed and the torque delivered from the power source 34 to achieve an optimal grass cutting condition.
In one example, the high-efficiency lawn maintenance tool 20 can include multiple decks 28 on a single mower unit.
In yet another example, the lawn maintenance tool 20 can include a formed handle (e.g. in the frame 24 or the deck 28) such that the handle corresponds with an opening in a corresponding shipping container. When the need arises to move the lawn maintenance tool 20 during shipping or storage, an operator can simply hold the lawn maintenance tool 20 via the handle in the chassis through the hole in the box. This can provide much more reliable shipping container movement, as the container (e.g., cardboard box) will simply move along with the encased lawn maintenance tool 20.
Another possible benefit to the described apparatus is a reduction in the revolutions per minute (rpm) required for optimal grass cutting. For example, the relatively high-speed rotation of typical lawn mower blades can be reduced by as much as 33%. This can enable a reduction in mower operating noise and a reduction in operation energy needs. In one example, the high-efficiency mower can operate at about 2,200 rpm with a projected 12,000 foot per minute (fpm) blade tip speed. This is a significant reduction from a standard 21-inch diameter system that may operate at 3,200 rpm and have a 19,000 fpm blade tip speed. In some examples, it has been shown that the cutting frequency (how many times a blade cutting surface contacts a blade of grass) can be more important than the tip speed of the mower blade.
The described lawn maintenance tool 20 can also include features that snap together and snap apart. In this way, it is possible to have an end consumer open the shipping container of the mower and put it together with minimal tools or no tools at all. Furthermore, many if not all maintenance items can include the snap together and snap apart features to eliminate the need for tools for regular maintenance tasks.
While preferred embodiments of the present disclosure have been described, it should be understood that the present disclosure is not so limited and modifications may be made without departing from the present disclosure. The scope of the present disclosure is defined by the appended claims, and all devices, processes, and methods that come within the meaning of the claims, either literally or by equivalence, are intended to be embraced therein.
This application claims the benefit of U.S. Provisional Application No. 62/171,475, filed Jun. 5, 2015 and U.S. Provisional Application No. 62/325,490, filed Apr. 21, 2016, the entire disclosures of which are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62171475 | Jun 2015 | US | |
| 62325490 | Apr 2016 | US |
