Low Profile Mower

The present invention is directed to a battery powered mower with a low profile design that minimizes the height of the mower to make the mower easier to operate and store. The low profile design places the cutting blade motor in the center of the deck volute so that it doesn't extend above the volute. Additionally, the batteries do not include a cover and so holes are located within the housing to drain away any water that collects. The invention also covers a simplified manufacturing process for the terminal blocks for the battery and a rear door. Lastly, the invention includes a cable guide to prevent the electrical cable from pinching when the handle is folded for storage.

FIELD OF THE INVENTION

The present disclosure relates to an electric battery powered outdoor lawn mower with a low profile.

BACKGROUND OF THE INVENTION

Electric battery powered outdoor lawn mowers are known in the art. These mowers typically use removable batteries that power the cutting blade motor and drive wheel motor (if applicable).

Electric mowers have gained in popularity in recent years because of their convenience and ease of use over gas powered mowers. Electric mowers eliminate the need for messy gasoline and oil, and requires less maintenance. Additionally many gas mowers have a pull cord starter as compared to a push button start of an electric mower.

Furthermore, having removable batteries allow for the easy recharging of the battery. The batteries can be small and portable so that they can be transported from the garage to the home, and eliminate the need to go to gas stations.

Many battery powered electric mowers position the batteries centrally above the mower deck, mimicking the look of traditional gas powered mowers. The batteries are typically placed inside a housing with a closable door to protect the batteries from water and other outdoor contaminants. These battery housings protrude upwardly from the deck and create large obstacles that can make maneuvering around or under bushes or other structures more difficult. These large battery housings also require increased use of plastic materials which leads to increased manufacturing costs.

A further issue with battery powered mowers is that the electrical cables must be run between the motor and the battery and controls. The cables are run from the motor to the user controls on the handle, and are secured to the handle with plastic ties. When the mowers are folded into a storage position, the handles are folded over the deck and the cables are often “pinched” by the handles. Repeated pinching of the cables can damage the cable.

BRIEF SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a battery powered mower includes a low profile design that minimizes the height of the mower to make the mower easier to operate and store. The low profile design places the cutting blade motor in the center of the deck volute so that it doesn't extend above the volute. The batteries are angled into the volute to further minimize the height.

The batteries for the mower are held by a housing that is placed over the deck. The housing provides a pocket for the batteries to sit in, but does not include a cover, so the batteries are exposed to the environment. Drainage holes are located within the housing so that any water that collects in the housing has a means of egress. The advantage of not including a cover is that again lowers the overall height of the mower and reduces the manufacturing cost.

In another aspect of the invention, the manufacturing of the mower is simplified by securing the terminal block for the battery on a pair of rails, and then sliding this subassembly onto grooves molded into the housing. Current plastic manufacturing processes pose challenges with obtaining specific geometry for the tooling needed for the parts. The present solution provides a simplified battery mounting geometry with low cost tooling in two separate parts (no slides, collapsing cores or other intricate tooling design needed). This design also maintains the vertical structural support by using an interlocking rail system where previous designs relied on fasteners to support the battery rail system.

In another aspect of the invention, the assembly of the mower is improved by securing the rear door of the mower to the housing, and then securing the housing and rear door to deck. By attaching the rear door to the housing first, the complexity of the assembly process is reduced. The rear door spring requires a large pre-load in order to comply with regulatory requirements. Typically, a person assembling the unit must hold the rear door assembly (rear door, pivot rod, and pre-loaded spring) to the deck while the housing is moved into place. Since this assembly is pre-loaded with a high spring force it causes the process to be very difficult. The method of the present invention separates the traditional process into two separate steps. First the rear door assembly (rear door, pivot rod, spring) is assembled to the housing with the pre-loaded spring leg in the housing (the spring leg attached to the housing is what allows the assembly to be separated from the deck). The housing design is such that it prevents the assembly from wanting to naturally separate with the spring force. The second step then brings the rear door assembly to the deck for final assembly.

In yet another aspect of the invention, the deck of the mower includes a cable guide adjacent the handle. Electrical cables are run from the motor up the handle pole to the user controls on the handle. When the handle is folded over the housing for storage, the handles tend to “pinch” and damage the cable. The cable guide secures the cable away from the pinching location reduces the likelihood of damage.

DETAILED DESCRIPTION OF THE INVENTION

FIG.1shows an electrically powered mower10as contemplated by the present invention andFIG.2shows an exploded view of the mower ofFIG.1. The mower10includes a deck12that is supported on the ground by four wheels22. A housing14covers the deck12and a handle18is connected to the rear of the deck12by two pole sections18A.

A rear chute door16is secured at the rear of the mower which can be opened and closed. In the open position, as shown inFIGS.1and2, a collection bag20is attached to catch any grass clippings or other debris cut and expelled by the mower. When the chute door16is closed, the grass clippings are trapped within the deck12and the grass clippings are mulched. A side chute door17is also provided so that the user can expel the grass clippings without mulching if desired.

Referring now toFIGS.3and4, the deck12is formed by a circular volute30with a hole or cavity32in the center. A motor34for driving a cutting blade is secured within the cavity32so that it's wholly contained within the cavity. In other words, the height of the motor34does not extend above the height of the volute30. This allows for the efficient use of space and reduces the overall height of the mower.

Referring now toFIG.3, the housing includes two openings40for battery connectors42(shown inFIG.2). To the rear of the openings40are two corresponding access pads44. As can be seen best inFIGS.4-6, the battery connectors42and access pads44are angled upward from front to rear.FIG.6shows the inserted batteries46, which are slid onto the battery connectors42from the rear.FIG.9shows an exemplary battery46having a groove48, which correspond to a tongue or rail61on the battery connector42(FIG.10). At the rear of the battery46is an interlock lever50that locks the battery to the battery connector42.

In order to minimize the height of the mower, the batteries46are inserted from the rear of the mower (as opposed to dropped in from the top). It is for this reason that the battery connector42and access pad44are angled so the user can access the battery46more easily. To further improve access to the battery, the access pads44are formed below the battery connectors42to provide access to the bottom of the battery making it easier for a user to grasp.

As can be seen inFIG.4, without the batteries the upper surface of the housing14forms the topmost surface of the mower.FIG.6shows the mower with the batteries46, with the batteries46slightly protruding above the height of the housing14. The extent that the batteries extend above the housing14will depend on the size of the battery, with batteries coming in different physical sizes depending on its energy capacity (for example a 2 amp-hr. battery vs. a 4 amp-hr. battery). Therefore, a battery with a low energy capacity could be small enough to stay below the housing. But even so, the configuration in the present invention reduces the height of the mower as compared to mowers where the batteries that are dropped in from the top.

FIG.7is another view of the mower showing the position of the motor34in the well of the deck12, and the position of the battery46over the motor34.FIG.8is a closeup view of the motor34and battery46ofFIG.7.

Referring now toFIG.10, the battery connector42is made up of two plates60that capture a terminal block62. Using the battery connector42subassembly improves the manufacturing and assembly of the mower since molding a separate battery connector for holding the terminal block is easier than molding this feature into the deck or housing. The plates60are held together with two screws64. Once assembled, the battery connector42is slid into the opening40in the housing14(seeFIGS.11and12), and then secured in place by screws66(seeFIG.13).

FIG.14is a top view of the mower showing the sectional line forFIG.15.FIG.15shows the rail61for the battery connector42that aligns with groove63in the housing14for holding the battery connector42. The battery connector42also includes an opening allowing the contacts for the terminal block62to extend through for connection with the battery46.

Using a rail61and groove63structure allows the battery connector42to support greater weights since the load is distributed along the length of the rail61. This can be an issue since user's often place heavy objects on top of the mower. The screws66are used to simply hold the battery connector42in place and keep it from sliding backward, and are not needed to support the weight of the battery connector42.

Furthermore, an embodiment of the invention shows that the battery connector42does not have a cover for the batteries14. This further minimizes the height of the mower and the amount of plastic or other materials needed. It also decreases the number of steps needed to insert or remove the batteries.

However, without a cover, the batteries are exposed to the elements, and if it rains, small amounts of water may collect in the battery connector42and access pads44. Because the battery connector42and access pad44are angled, any water flows to the bottom front portion of the two areas, and drainage holes are provided in these locations. Furthermore, the center of the battery connector42and access pads44are slightly raised so that any water flows outwardly away from the center.FIGS.16and17show front drainage holes70and rear drainage holes71in the housing14in the area of the battery connector42and access pad44, respectively.

FIGS.18,20and21shows the front drainage holes70connected to channels72formed in the deck12of the mower. The channels72carry the water from the housing14through the deck and out through an opening74in the bottom of the deck. The channel72is isolated from the rest of the deck, and importantly, from any electronics contained within. For exampleFIG.20shows the motor control PCB76is located adjacent the motor34and near the channel72.

In another embodiment of the mower, the channels72can be made of a flexible plastic tubing, which may simplify the injection molding of the deck. This is shown inFIG.19as reference numeral73. Here, as in the previous embodiment, the channels73transfer any water through the deck and out the opening74.

In an embodiment of the invention shown inFIGS.22-24, the rear drainage holes71open to an interior surface of the volute30. The water flows down the volute surface (as shown by the arrows80) until it reaches an opening78in a bottom of the deck12.FIG.23shows the location of the motor control PCB76, which is spaced from the surface of the volute30to prevent water contacting the PCB76.

FIG.25is top view of the mower deck showing the position of the motor control PCB76andFIG.26is a top view with the PCB76and other wiring removed for clarity. It shows the two openings74on opposite sides of the deck for the front drainage hole70, and two openings78for the rear drainage holes71. Several additional ventilation and drainage holes82are provide around the deck.

In another feature of the invention,FIGS.27-35show an embodiment of the invention for assembling the rear door16to the mower. Traditionally, assembling the doors to the mower is time consuming and often fatigues factory workers because of the need to control the high tension door spring. The present invention pre-assembles the door to the housing before it is assembled to the deck, which alleviates these drawbacks.

FIG.27shows the rear door16having a bracket90for holding a rod92. The rod92includes a high tension spring94to bias the door closed. The rod92and spring94are first inserted through holes within the ends of the bracket90.

A first end of the rod92is then inserted through a pair of elongated slots96(seeFIG.32) in a first arm100of the housing14. Once the rod92is fully inserted, it can be angled down and inserted into a similar elongated slot96in a second arm102, as shown inFIGS.28and29. The rod92can then be centered to engage with both arms100and102as shown inFIGS.30and31.FIG.32shows the rod92in the slots96(rear door16removed for clarity), andFIG.33shows a rear sectional view with portions of the arms100and102removed to better show the hubs200for holding the rod92. The housing14now temporarily holds the rear door16while it is secured to the deck12.

FIG.33Ais rear sectional view showing the deck12having several pillars97that support the rod92as the housing14and rear door16are secured to the deck12. The outer ends of the deck14have arms98that support the rod and keep it from moving laterally, eg. side-to-side when fully assembled.

Yet another feature of the invention is a cable routing system to protect the electrical wiring from damage. As shown earlier inFIGS.1and2, an electrical cable110connects the motor34to a control unit112on an upper portion of the handle18. The control unit112starts the motor34through the bail handle114. It can also include a safety lockout key115which prevents the motor34from starting unless the key115is inserted.

In a typical mower, a cable generally exits the housing and/or deck around the lower end of the handle. The cable is typically run up the handle with plastic ties used to secure the cable to one of the handle arms. When the handle is folded over for storage, the handle end can pinch the cable and damage it.

FIGS.36-39show an embodiment of the present invention that uses a raised arm12A of the deck12to divert the cable away from the handle.FIG.36shows the cable110being clamped against the raised arm12A by a switch housing118.FIG.37shows the arm12A of the deck with the switch housing118removed. The arm12A includes cutouts116for securing the cable110well below the end point of the handle18so that it does not pinch the cable110. So when the handle18is folded, as shown inFIGS.41, it does not pinch the cable110.FIG.36shows the cable110when the handle is in the upright position, andFIG.41shows the cable110when the handle is folded.

In another embodiment of the invention, the switch housing118includes a switch120that is actuated by the folding of the handle18.FIG.36shows that the handle18does not contact the switch120when the handle is in the upright position. This allows the motor to be actuated in the normal course of use.FIG.39shows the handle18in the folded position where it engages the switch120. When the switch120is actuated, it acts as a safety measure and prevents the motor from turning on.