This is a continuation-in-part of United States Serial No. 506,903 filed April 10, 1990.

Field of the Invention

This invention relates to power mowers and more particularly to power mowers powered by electrical motors.

Background of the Invention

Present day power mowers can be powered either by a 4-cycle gasoline engine or a 2-cycle gasoline engine for providing power to drive a cutting blade of either the rotary or reel type. Other power mowers have an electric motor that drives a cutting blade of either type the rotary or reel type. Such electric motor powered mowers have the power supply provided to the motor through an extensible cord which connects to a standard domestic power supply.

The use of gasoline engine constitutes a substantial source of air pollution which in time could become regulated by the E.P.A. as are larger engines for powering automobiles and other motor vehicles. The alternative to such gasoline engines is a cord type electric motor driven mower. Such mowers, however, are not as mobile as gasoline engine mowers in that they must be connected to a power supply by a cord during their operation. Such power cords are susceptible to being cut by the blade to produce exposed power leads. Additionally, while not a direct polluter, such electric powered mowers are powered from a central power plant which, if fossil fuel fired, can be a significant source of pollutants unless suitable waste recovery systems are incorporated in the central system.

Summary of the Invention

Accordingly, a feature of the present invention is to provide a powered mower with a power supply that has little or no emissions therefrom.

Another feature of the present invention is to provide an electrically powered mower with a power supply that does not reguire a cord for supplying electrical power thereto.

Another feature of the present invention is to provide a powered mower with a rotary blade driven by an electrical drive motor which is connected to a cordless source of power including a primary power source for providing electrical power to the drive motor and further including a secondary source of power that generates power solely on exposure to light energy.

Still another feature is to provide powered mowers of the type set forth in the preceding objects wherein the source of power includes a cordless power supply for an electric drive motor located on the upper surface of a protective housing; the cordless power supply including a primary source of electrical power for driving the electric motor and further including a secondary source of electrical power for charging the primary source of electrical power as power is supplied from said primary source of electrical power to the electric drive motor.

Yet another object of the present invention is to provide an electric power mower having a solar panel with solar cells thereon for charging onboard batteries which supply primary power to the electric motor of the electrically powered mower so as to eliminate the need for a power cord.

Still another object of the present invention is to provide a power mower with a rotary blade driven by an electric motor having a primary source of power defined by rechargeable batteries mounted on the mower and including a secondary source of power mounted on the mower for charging the rechargeable batteries as they supply power to the drive motor.

Another object of the present invention is to provide power mowers of the preceding object wherein the secondary power source is a solar panel located in overlying relationship to the drive motor so as to intercept sunlight from different directions as the mower is driven in a cutting pattern across a lawn surface.

Yet another object of the present invention is to provide a solar powered mower having the supplemental power source formed as separate solar panels or solar cells formed on the sides and front of the mower deck or blade housing and/or the handles thereof.

Still another object of the present invention is to provide a solar powered mower having the supplemental power source formed as separate solar panel or solar cells formed as covers on a grass catcher connected to the mower to collect grass cut by the cutting blades of the power mower.

Still another object of the present invention is to provide a solar powered mower which includes a rider platform thereon and wherein the

» solar power panels for an electric drive motor are formed covers over the front end of the solar powered mower.

Still another feature of the present invention is to provide such a powered mower wherein the solar panels or solar cells are mounted on outrigger panels which are extendable from the main housing of the power mower during use for greatest

sun exposure but which are retractable to define a compact storage configuration when the mower is not in use.

Still another object of the present invention is to provide a power mower with a solar power source including a shelter for the power mower and wherein the solar power source includes solar panels on the shelter to charge batteries onboard the power mower in conjunction with solar panels mounted on the power mower.

Yet another object of the present invention is to provide a solar powered mower including a solar panel or solar cell having output terminals and a connection circuit to the positive and negative terminals of a battery mounted on the power mower for powering a drive motor and wherein the connection circuit includes a capacitor which is charged by the solar panels when the panels are exposed to sun light and which is operative when the panels are not exposed to sun to provide supplemental battery charging current and wherein the connection circuit further includes a diode to protect the solar panel

or solar cell from backflow of current from the battery to the solar panel or solar cells when the panels are not producing a charging current.

Still another object of the present invention is to provide a solar powered mower of the type set forth in the preceding objects and features wherein the mower includes a safety switch in its electrical control circuit in the form of a attitude responsive switch on the mower that will disconnect the drive motor from the power sources when the mower is tilted or tipped through an angle which will expose the cutting blades to a user.

Yet another object of the present invention is to provide such a safety circuit of the preceding object wherein the switch is a mercury switch which is oriented to interrupt the power supply to the electric drive motor when the mower is tipped.

Still another object of the present invention is to provide the solar panels as flexible amorphous silicon sprayed or dipped on surfaces associated with the mower thereby allowing the full surface area of a mower deck, a mower chassis or a bagging unit to become a generator of solar power.

These and other features, advantages and objects of the present invention will become more apparent in view of the accompanying written description of a preferred embodiment of the invention when taken in conjunction with the appended drawings wherein:

Brief Description of the Drawings

FIG. 1 is a side view of a power mower of the present invention;

FIG. 2 is an enlarged top elevational view of the power mower of FIG. 1 with a solar panel thereof removed;

FIG. 3 is a top elevational view of the solar panel of the present invention;

FIG. 4 is a side elevational view of the solar panel of FIG. 3; and

FIG. 5 is a top elevational view of another embodiment of a solar panel for use with the present invention.

FIG. 6 is a perspective view of another embodiment of the invention with solar panels located on the front, sides and top of the mower deck as well as on the handles thereof;

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 6 looking in the direction of the arrows;

FIG. 8 is a perspective view of still another embodiment of the invention which includes a power mower having a grass catcher with solar panels forming the exterior surfaces thereof;

FIG. 9 is a perspective view of another embodiment of the invention having solar panels or solar cells mounted on outriggers connected to the housing of a power mower driven by a battery powered electric motor and wherein control circuits connect the solar panels or solar cells on the outriggers to the battery for charging it during use;

FIG. 10 is a perspective view of a rider mower including a forward compartment with its roof formed with outer solar panels thereon;

FIG. 10A is a front elevational view of an electric motor powered rider mower including a flat protective roof having solar panels thereon for charging a storage battery on the mower;

FIG. 10B is a side elevational view of an electric motor powered rider mower including a sloped roof cover having such solar panels thereon;

FIG. 11 is a perspective view of another rider mower including a rider seat mounted as a pedestal forward of a mower platform and wherein solar panels are provided on the sides and front of the mower platform and also on the top of a rear mounted grass collector;

FIG. 12 is a perspective view of a solar garage for housing a solar charged electric motor driven power mower including a roof panel defining a solar panel or solar cells to supplement the battery charging of the solar panels mounted directly on the solar power mower;

FIG. 12A is a flat roofed version of the solar garage of FIG. 12;

FIG. 12B is another embodiment of the solar garage;

FIG. 13 is a circuit diagram of a solar panel charging circuit for an onboard mounted solar panel for charging a battery on a power mower which powers an electric motor for driving the cutting blade of the mower; and

FIG. 14 is a fragmentary view of a safety switch for cutting off the power supply across the power terminals of an electric drive motor on a solar powered mower when the mower is tilted or tipped to expose the cutting blades thereof.

Description of a Preferred Embodiment

Referring now to FIG. 1, a powered mower 10 is illustrated including a protective housing 12 for a rotary blade 14. The blade 14 is suspended within the protective housing 12 by a drive train 16 including an electric clutch and brake unit 18. The drive train 16 is connected to a direct current energized electric drive motor 20 by the drive shaft 20a of the drive motor. The motor 20 is supported on the top 12a of the protective housing 12.

The powered mower 10 is powered by a primary source of power in the form of rechargeable batteries 22, 24 located on either side of the drive motor 20 where they are secured by suitable hold down fixtures (not shown) to the top 12a of the protective housing 12.

One feature of the present invention is that the provision of an onboard source of power for the drive motor 20 eliminates the need for power cords as presently found on electrically powered mowers. The present invention thereby obviates the attendant problem of accidental cutting of power cords during mower operation.

Another feature of the present invention is the provision of a solar cell system 30 for charging the batteries during mower operation to maintain the rechargeable batteries 22, 24 at a functional operating level. The provision of an onboard recharging source eliminates the need to connect the batteries for recharging from a central power source so as to eliminate power plant emissions which can be generated during such recharging. Initial charging will be necessary as may be periodic charging due to some loss from sitting, unless the mower is left in

the sunlight after use until the next mowing. A further advantage of electric powered mowers is that they eliminate pollutants and emissions produced by mowers of the type powered by either four or two cycle engines fueled by existing sources of fossil fuel. Such fossil fueled, internal combustion engines do not include emission control systems and in the aggregate produce combustion products that constitute a substantial source of nitrous oxides, carbon monoxide, carbon dioxide, as well as direct evaporation of the fuel supply all requiring regulation in order to protect the world environment.

A powered mower 10 having the aforesaid rechargeable batteries 22, 24 and solar ceil charging system 30 is readily adaptable for use with known drive systems. For example, the powered mower 10 can have a conventional handle 26 with a control module 28 for setting the control modes to operate a standard drive transmission 32 having either a pulley 34 or a gear on the drive shaft 20a. A drive belt 36 from the pulley 34 passes over a driven pulley 38. The driven pulley 38 can connect to a shaft 40 carrying a worm gear 42 that engages a worm 44 on the shaft 46 of a drive wheel 48. Such a drive transmission or its equivalent can be used to turn

the wheel (or wheels) of the powered mower 10 allowing the power from the onboard electrical power source to pull the mower over grass terrain to allow the rotating blade 14 to cut the individual blades of grass in a known manner.

In the illustrated arrangement and as best shown in FIG. 2, the rechargeable batteries 22, 24 have negative terminals 50 thereof connected to the negative terminal 52 of the D.C. drive motor 20 by suitable leads 54. Likewise the positive terminal 56 of the motor 20 is connected to either an on-off switch 28a on the control module 28 or to a variable speed control 28b thereon. When the switch 28a is turned on the power circuit is completed across the windings of the D.C. electric drive motor 20 through suitable leads 58 connected to the positive terminals 59 of the batteries 22, 24.

If a variable speed control 28b is used, the electronic speed control can produce a known pulse width modulated signal to the windings of the drive motor 20 to vary the r.p.m. of the drive motor 20 to control the cutting speed of the blade 14 alone. If a transmission 32 is used to propel a

drive wheel 48, the speed of the entire unit can be varied by varying the output speed of the drive motor 20.

The electric clutch 16 can serve as an electric brake by directing opposite polarity power thereto when a handle safety bar 26a is released. If the user's hands are removed from the handle 26 the safety release bar 26a conditions a safety switch 26b to condition the clutch 16 to instantaneously provide a stop action for the cutting blade 14. The clutch 16 also absorbs shock if the blade 14 strikes an object.

As a further safety feature, the onboard powered electric motor 20 of the present invention can be instantly stopped by utilizing the safety switch 26b to reverse the battery polarity to the electric motor 20 when it is turning the blade 14 in its normal cutting direction. When the motor stops the switch 26b disconnects the motor 20 from the batteries 22, 24 until the switch 26b is reset to a starting mode. Alternatively, an electromechanical brake band can be provided to apply emergency braking directly to a rotating clutch or drum assembly connected to the drive shaft 20a.

In operation, the storage cells or batteries 22, 24 are either dry charged or sealed units which are installed on the mower as precharged units from the manufacturer. If required the batteries 22, 24 can receive their initial charge of power from an external charging source. Once charged, however, the batteries 22, 24 can be operated for extended periods of time by utilizing the solar cell system 30 as a supplemental power source to maintain the initial charge on the primary source of power defined by the batteries 22, 24.

The solar cell system 30, more particularly, includes a pair of solar panels 60, 62 joined at a ridge line 64 at a point raised above the top of the electric drive motor 20. The solar panels 60, 62 each have a plurality of solar cells connected so as to produce a voltage and current supply on a lead line 66 which is generated as direct current and voltage when the cells are exposed to either the sun or to a bright light source. A voltage regulator 70 is connected either to a charging outlet 72 for the initial charge or to the lead line 66 to control the current flow with respect to the batteries 22, 24. The voltage regulator 70 is operative to maintain a safe charging level of voltage and current as

additional voltage and current is directed from the solar cell system 30 to the batteries to maintain them at a functional operating level.

In the embodiment of the invention in FIG.

5, the solar panels 60, 62 are replaced by a generally conically configured solar panel 80. In both the case of the solar panel 60, 62 and the conically configured solar panel 80, the solar cell system 30 is operative to intercept sun rays from a plurality of directions during operation of the mower 10 as the mower is passed in different cutting patterns across a lawn surface.

In all of the aforedescribed embodiments of the invention, as well as the following embodiments of the invention, the use of solar cells carried, mounted or attached to the cutting device operate so as to supply a charging voltage and current to the battery to extend the cutting time of the cutting device and to supply a convenient method of charging the battery after and during its use, and to increase the life of the battery.

The extended cutting time and extended life of the battery is accomplished due to the solar cells supplying voltage and current to the battery while it is in use, thereby reducing the internal resistance of the battery, allowing the battery to produce or supply more current to operate the cutting motor for a longer period of time.

By reducing the internal resistance of the battery while it is in use, the internal stress load of the battery is reduced while it is supplying voltage and current to the motor load. Accordingly, internal heat and plate warpage are reduced and the battery has a longer life.

Since recharge time is in direct proportion to the time that the mower is used, the recharge time can be reduced due to the battery retaining more of its energy, as long as the battery is not drained completely.

Automobile type batteries, otherwise known as starting batteries, are not useful devices for cutting equipment. They can supply high current for only a short period of time and cannot withstand deep cycle discharge and recharge without damage.

Special design "deep cycle" batteries such as, but not limited to, gell cells, nickel cadmium, sealed recirculating gas and other "deep cycle" non- spillable types are designed for deep cycle discharge and recharge on a continuous basis without damage. Such batteries are able to supply the necessary current over a longer period of time, allowing the cutting device to perform useful work without damage or dangerous spillage of their internal liquids, or the release of dangerous gasses.

The solar cells or photo voltaic cells used on or attached to the cutting or mowing device are not limited to solid, brittle types such as crystalline silicon types. Flexible or conforming types can be applied in any configuration, such as amorphous silicon which can be sprayed on, dipped onto or otherwise applied to any given surface, allowing utilization of the entire deck or chassis or bagging unit as a solar generator. The flexible type can be used in conjunction with the solid types of solar cells to allow maximum power generation for the mower or cutter application.

Further, the solar cells or solar panels can be designed and constructed as a "retrofit unit" to be applied onto existing battery operated or battery powered mowers or cutting devices to perform the same function as herein described.

Referring now to the embodiment of the invention shown in FIGS. 6 and 7, a solar powered mower 82 is shown having a mower deck carrying an electric drive motor 84 for the cutting blade which is like the blade shown in the previous embodiments which is connected to the output shaft of the electric drive motor 84 by suitable power train components (not shown) . In this embodiment the solar panels 90 for defining a secondary source of electrical power for charging a battery 86 that powers the electric drive motor 84 are mounted on the sides, top and front of a mower deck 88. More particularly there are two side solar panels 90a, 90b which are connected one either side of the mower deck 88 and arranged at an angle which is best suited for a particular latitude in which the mower is used. In the illustrated arrangement the angle is approximately 45 degrees from the vertical which is best suited for more northern latitudes. The mower 82 further includes a front solar panel 90c arranged

on the front of the mower deck 88 and arranged at a similar angle. The mower 82 further includes a horizontal solar panel 90d covering the motor 84. Additionally, a solar panel 90e is supported on the push handles 82a, 82b of the mower 82. In all cases, the positive and negative terminals of each panel are connected to the terminals of the voltage regulator 70 as shown at 67 in FIG. 2.

The embodiment of the invention shown in

FIG. 8 includes a solar powered mower 92 having a drive motor 93, storage battery 95, and charging circuit 97 like that in the embodiment of FIGS. 1-4 but in this embodiment the secondary source of electrical power for charging the power battery is defined by solar panels or cells 94a, 94b and 94c mounted on the outer surface of a rear mounted grass collector 96 connected to the deck 98 of the mower 92 at the aft end thereof.

The embodiment of the invention shown in FIG. 9 is a outrigger solar power mower 100 which includes a deck 102 having a electric drive motor 104. A primary power source for the electric drive motor 104 includes a battery 105 connected to a charging circuit 106 for receiving power from a

secondary power source in the form of a pair of spaced solar panels 108, 110. Each of the solar panels 108, 110 is carried on a outrigger panel 112 that is pivotable between a run position shown in FIG. 9 and a storage position shown in outline form at 113 in FIG. 9. More particularly, the outrigger panels 112 each have an inboard edge 112a connected by hinges 114 to raised brackets 115 on the mower deck 102. The outboard edge 112b of each of the outrigger panels 112 have wheels 116. Lock members 118 on each panel edge 112b snap together to hold the outrigger panels together in the raised position 113.

When the solar powered mower 100 is stored the outrigger panels 112 are pivoted upwardly about the hinges 114 until the lock members 118 are engaged at which point the solar panels 108, 110 are located within the outside side dimensions of the deck 102 so as to define a compact storage configuration.

The embodiment of the invention shown in FIG. 10 is a rider mower 120 having a rear mounted seat 122 and a front located housing 124 which encloses an electric drive motor, electric storage battery and suitable charging and power circuitry for interconnecting them to a solar power source 126 on

the rider mower 120. The charging and power circuits are like those described in the embodiment of FIGS. 1-4. In this embodiment the solar power source 126 includes a frame 128 on the front housing 124 which carries solar panels 130-134 for exposure to the sunlight to produce a charging current flow to a battery pack (not shown) for an electric drive motor for driving a cutting blade in a cutter deck 136 as well as a transmission 138 for transferring power from the drive motor to rear drive wheels 140. The drive train can take many forms and this embodiment is not cited for the drive train type but rather for another arrangement for supporting solar panels for charging an electric storage battery for powering the electric drive motor of a rider mower.

The embodiments of the invention shown in FIGS. 10A and 10B show arrangements for supporting solar panels above a rider motor on sunroofs thereof. The embodiment of FIG. 10A shows a roof type mount wherein solar panels 142, 144 are formed on a sloping roof 145 for protecting the driver of the rider mower. The embodiment of FIG. 10B shows a solar panel 146 formed on a flat roof 148 for protecting a driver.

The embodiment of FIG. 11 shows a rider mower 150 having a center mounted seat 152 located above a ride platform having a mower deck 154 and a front mounted steering pedestal 156. A side outlet 5 156 from the mower deck 154 is connected by a discharge chute 156 into a rear grass collector 158. In this embodiment the source of secondary power for charging an onboard electric storage battery for powering an electric drive motor is comprised of 10 _. solar panels 160, 162, 164 carried respectively by the pedestal 156, the seat frame and the top of the rear grass collector 158.

FIG. 12 shows a solar garage or shed 160 15 for housing a solar powered mower of the type set forth above. The solar garage has sides and a roof 162, 164 respectively for protecting the mower. It also includes a solar panel 166 formed either on a slope or flat to collect solar energy. The solar 20 panel 166 has terminals thereof connected to a power cord or to a power plug 168 that will connect to spade terminals 170 on the front of the power mower when it is housed within the solar housing. In FIG. 12A the housing is shown in the flat roof 172 version 25 and in FIG. 12B a garage version 174 is shown

including panels 174a, 174b having a power cord 174c adapted to connect to a charging receptacle 176 on a riding mower 178.

The above-described mower housings and garages all carry solar panels which can be used to charge storage batteries on solar powered mowers and in conjunction with the solar panels carried on such mowers or as a separate source of power for electric storage batteries on mowers that have an electric drive motor but do not have onboard solar panels. In both cases, however, the shed, garage or other shelter which carries the solar panels will serve to protect the mower from the elements when not in use while charging the onboard electric storage batteries of the mower when the sun is out.

In all cases, the maximum solar charging efficiency is achieved by the proper orientation of the solar panels to achieve maximum exposure to the suns rays. Thus in latitudes closer to the equator the solar panels are arranged more horizontal to capture rays from a sun position more overhead which more northern and southern latitudes will require

solar panels inclined more toward the vertical to capture rays from sun positions lower toward the horizon.

As shown in FIG. 14, a safety switch 180 is utilized on the mower to preclude its starting or running when the cutting device is tilted or tipped in extreme directions. This switch is a mercury switch 180 mounted on a pedestal 182 on mower deck which is able to be oriented to actuate or deactivate the electrical continuity to the running circuit through wire 58.

As shown in FIG. 13, a capacitor 184 may be placed across the output of the solar panels 186 to stabilize the output voltage delivered to the battery 188.

Thus, during sunlight periods when the panels 186 supply current, the capacitor 184 stores the output of the solar cells while, at the same time, allowing the battery to be charged by the solar cells. Then, when shade is encountered and the solar cells are not producing sufficient current, the stored energy within the capacitor 184 is discharged into the battery 188 until the solar cells receive

additional sunlight, thereby to continue charging the battery and recharging the capacitor. The capacitor must be at least the rated voltage output of the solar cell or cells to withstand the voltage and can be as high a capacity as necessary to be able to deliver its charge for a given amount of time.

A diode 190 is placed in series with the charging circuit 192 to prevent voltage and current feedback from the battery 188, during period of no sun, when the panels are not producing voltage. The diode 188 thereby prevent the voltage and current from the battery reaching the solar cells so as to damage them.

In all cases, the protective housing of the mower can be upsized to accommodate a larger number of rechargeable batteries to drive a larger load and likewise a larger support base is provided to accommodate a larger area of solar cells to provide the secondary source of power for charging the batteries.

While representative embodiments of the present invention have been shown and discussed, those skilled in the art will recognize that various changes and modifications may be made within the scope and equivalency range of the present invention.