US 20050230168 A1
Provided is an all-electric riding greens mower. The mower includes a frame which is supported for movement upon a plurality of ground engaging wheels and upon which are supported a modularly interchangeable power source and a plurality of reel lawn mowers. An electric motor provides driving torque to enable movement of the mower between and over golf course greens or other surfaces to be mowed, electric motors provide driving torque for each of the reel lawn mowers. The interchangeable power source provides electrical energy for driving the electric motors, including the primary mover and the electrical motors for the reel type lawn mowers. The modularly interchangeable power sources may comprise a bank of batteries, a motor/generator set, a fuel cell, or a combination of these. The power source may be easily exchanged in the field for another, freshly charged power source. Exchange occurs using either a fixed change stand or a mobile change stand. The change stands are configured to facilitate exchange by reducing friction caused by the generally weighty power source. The power source is delivered to the fixed stand on towable trailers.
1. A trailer for supplying electrical energy to a self-propelled riding vehicle, comprising:
a power source;
a frame for supporting said power source;
a pair of ground engaging wheels for supporting said frame; and
a tongue extending from said frame and having a hitch for connecting to said vehicle;
wherein said power source may be connected to said self-propelled riding vehicle in order to supply electrical energy to said self-propelled riding vehicle.
2. The trailer of
3. The trailer of
4. The trailer of
5. The trailer of
6. The trailer of
7. The trailer of
8. The trailer of
9. The trailer of
10. The trailer of
11. The trailer of
12. The trailer of
13. The trailer of
This application is a divisional of U.S. patent application Ser. No. 10/797,521 filed Mar. 10, 2004, which is a divisional of U.S. patent application Ser. No. 10/268,358 filed Oct. 10, 2002, which is a divisional of U.S. patent application Ser. No. 09/489,124 filed on Jan. 21, 2000, now U.S. Pat. No. 6,571,542 issued Jun. 3, 2003, which claims the benefit of U.S. Provisional Patent Application No. 60/126,153 filed on Mar. 25, 1999. The disclosures of the above applications are incorporated herein by reference.
The present invention generally relates to electrically-powered riding mowers for use on golf courses and other large grounds, and more particularly relates to electrically-powered riding mowers that utilize modular, interchangeable electrical power sources which may include a bank of batteries, a motor/generator set, a fuel cell or combination thereof, for providing electrical power to the mower.
The assignee of the present invention recently introduced an all-electric riding greens mower. The mower of this all-electric riding greens mower is described in detail in U.S. Pat. No. 5,406,778, issued Apr. 18, 1995, the disclosure of which is hereby incorporated by reference. The triplex riding mower disclosed in this patent has a bank of batteries supported near the rear of the frame of the riding mower which provides electrical power for operating the main drive electric motor, three reel motors, and three lift motors for raising and lowering the reel type mowing heads as needed. The main motor drives a transaxle that provides a driving force to the two forward wheels of the triplex mower. The three reel mowers each directly drive one of the reels, which may be operated independently. The three lift motors individually drive a screw-type lift mechanism which raises and lowers a head much the same way that conventional hydraulically-powered single-rod cylinders do. The mower includes a foot pedal controlled by the operator which actuates a potentiometer which directs forward or reverse motion of the vehicle at any desired rate of speed, within the limits permitted by the drive motor control circuitry and by the power capabilities of the main motor and batteries. Heavy duty contactors switchably apply electrical energy to the reel motors, which are provided with the full voltage of the battery pack, which is nominally 48 volts presently obtained by eight 6-volt batteries wired in series.
There are numerous advantages to using an all-electric riding greens mower. These include very quiet operation, because there is no noisy internal combustion engine. Another advantage is the absence of hydraulic devices and accompanying hydraulic oil on the machine, which eliminates the possibility of hydraulic oil leaks. As is known, hydraulic oil leaks in conventional hydraulically-driven and hydraulically-powered turf care equipment can significantly damage a golf green or fairway if undetected by the mower operator.
Another major advantage of the all-electric greens mower is that it does not produce byproducts of combustion, and thus can operate in areas where the use of conventional internal combustion powered mowers is prohibited due to pollution concerns and regulations.
While the disclosed all-electric greens mower is quite satisfactory and much appreciated, it is difficult and impractical to mow large areas, such as fairways or parks with that style of mower, even when appropriate reel-style mowing heads are installed. The range of the battery packs carried by the present mowers remain inherently limited by the power capabilities of conventional batteries.
One challenge presently faced by many golf course operators is that municipalities and communities, especially those which have residential homes bordering the golf courses, restrict by ordinance the hours during which the fairways and greens may be mowed. Homeowners have tired of noisy mowing equipment awakening them during the early morning hours, between 5:00 a.m. and 8:00 a.m., and disturbing them in their leisure during the later evening hours, between 7:00 p.m. and 10:00 p.m., when they expect peace and quiet in their neighborhoods. Golf course operators, on the other hand, dislike mowing their courses during peak golfing times, between 7:00 a.m. and 7:00 p.m. during the golfing season. This challenge presents particular difficulties for golf course owners whose courses are continuously busy, and usually have a waiting list of people seeking tee times.
A sufficiently quiet mower, such as an all-electric mower would allow for mowing fairways and greens on golf courses even where communities have instituted noise-limiting ordinances. This is because the all-electric mowers are very quiet. Unfortunately, the battery range of a riding electric mower with one bank of batteries (even though the battery weight is in excess of 400 pounds) is limited. Battery-powered commercial mowers, therefore, remain impractical for mowing large areas due to the typically extensive recharge times required to fully recharge the battery and the undesirable need to interrupt the mowing process (which the golfers wish to have completed as expeditiously as possible) while the batteries are re-charging.
Therefore, it is a principal object of the present invention to provide an electrically-powered riding mower which is capable of mowing large areas of turf, such as golf course fairways, soccer fields, parks, and municipal grounds. A related object is to provide an all-electric riding mower which is capable of mowing large areas while producing very little noise and minimizing mowing interruptions to replace or re-charge the on-board power source.
Another object of the present invention is to provide an electrically-operated riding mower that utilizes modular, interchangeable electric power sources which may include, for example, a bank of batteries, a motor/generator set, or a fuel cell, individually or in combination, to provide electrical power to the mower. Still another object of the present invention is to provide removable, rechargeable electrical power sources on easily interchangeable trays, so that they can be quickly changed and moved about.
Yet another object of the present invention is to provide an additional electrical power source in the form of a towed power source mounted on a trailer which provides supplemental electrical energy to an all-electric battery-powered mower so that it runs longer distances.
Yet another object is to provide a preferred method for efficiently utilizing such electrically-powered riding mowers having towed power sources.
Yet another object is to provide changing structures which facilitate the removal of replaceable, rechargeable electrical power sources from turf equipment, such as the disclosed fairway mowers.
Yet another object is to provide a stacked vertical power source change rack, a horizontal power source change platform, and a towable power source change platform.
Still further objects of the present invention are set forth in and will become apparent from the following summary of the invention and the detailed description and claims thereafter.
In light of the foregoing problems and in order to fulfill one or more of the foregoing objects, there is provided, in accordance with a first aspect of the present invention, a self-propelled riding mower having a frame supported on a plurality of ground engaging wheels. The frame supports an electrical power source for supplying electrical energy to the mower and further supports a plurality of reel type lawn mowers which are movable between a raised position and a lowered position, in accordance with operation and non-operation, respectively. The reel mowers are driven by electrical motors which receive electrical power from the power source, which may be, for example, a battery pack, a motor/generator set, or a fuel cell. A prime mover having an electric motor is also supplied with electrical energy from the power source, where the prime mover is adapted to provide torque to one of the ground engaging wheels upon which the frame is supported.
There is provided in accordance with a second aspect of the present invention, a self-propelled riding mower having a frame supported on a plurality of wheels. A plurality of reel type lawn mowers are also supported by the frame and are movable between a raised, non-operative position and a lower operative position. The reel type lawn mowers are powered by electric motors which receive electrical power from the power source. A prime mover having an electric motor supplied with electrical energy from the power source provides driving torque for at least one of the ground engaging wheels. Further, the self-propelled riding mower includes support for at least a portion of the power source which engages and disengages the frame to enable removal and installation of the power source.
In a third aspect of the present invention, a self-propelled riding mower having a frame supported on a plurality of ground engaging wheels. The mower also includes a first power source and a plurality of reel type lawn mowers supported from the frame which are movable between a raised position and a lowered position. The reel type lawn mowers are driven by electric motors receiving electrical power from the power source. Further, a prime mover comprising an electric motor supplied with electrical energy from the power source is adapted to provide driving torque to at least one of the ground engaging wheels. Further yet, a power source trailer is supported on a plurality of ground engaging wheels and supports a second power source. The trailer interconnects with the frame by a hitch so that the self-propelled mower tows the trailer.
In accordance with another aspect of the present invention, a power source change stand for switching power sources between a vehicle having interchangeable power sources and an auxiliary power source platform. The power source change stand includes a first support to support the power source on the change stand and a second support to support the power source on the change stand, one of which is empty. To change the power source, one of the two supports receives the depleted power source from the mower, while other supports support a fresh power source which is then placed on to the frame of the electrically powered vehicle.
There is provided in accordance with yet another aspect of the present invention, a trailer for supplying electrical energy to a self-propelled riding mower including a frame for supporting a power source and a pair of ground engaging wheels for supporting the frame. The trailer includes a tongue extending from the frame having a hitch for interconnecting to the towing vehicle. The power source is then interconnected to the towing vehicle in order to provide electrical energy to the towing vehicle.
These and other objects, advantages and aspects of the present invention may be further understood by referring to the detailed description, accompanying Figs., and appended claims.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The drawings form an integral part of the description of the preferred embodiments and are to be read in conjunction therewith. Like reference numerals designate the same or similar components or features in the various figures, where:
The present invention is directed to a riding greens mower powered directly by electric power or indirectly by electric power through a hydraulic drive system. For the purpose of providing a detailed description of the preferred embodiments of the invention, the invention is described as embodied as an electric or electrohydraulic triplex reel greens mower or a quintplex reel greens mower, each having a frame supported on at least three wheels, the defined number of reel-type lawn mowers supported from the frame member, an operator station including a seat from which an operator controls the function of the mower, and a source of electrical energy, such as on-board or towed battery packs, a motor/generator, or a fuel cell. It should be readily understood that the teachings of the present invention are not limited to the specific type of mowers described herein and can be extended to a variety of applications in the turf care industry and elsewhere.
Each of the reel lawn mowers are driven by an electric reel motor 111 of
In another embodiment of the present invention, the electrical power source 24 may be a fuel cell. As is well-known, a fuel cell is similar to a battery in that it produces electricity as the result of a chemical reaction. Often the chemicals reacting are merely hydrogen and oxygen. Fuel cells have a significant advantage over batteries because they do not run down like batteries. In this regard, as long as fuel and oxygen are supplied to the cell, it will continue to produce electricity. Consequently, a fuel cell merely requires refueling and not recharging. U.S. Pat. No. 5,248,566 entitled, “Fuel Cell System for Transportation Applications” discloses a fuel cell propulsion system for a wheeled vehicle, the disclosure of which is hereby incorporated by reference. Such a fuel cell system may be suitably adapted for use as a power source of the present invention.
The power source 24 also provides electrical energy to a drive motor or primary mover (not shown in
Mower 10 is operated from an operator station 30, which includes a seat 32 supported above frame 12 and power source 24 by seat support 34. Operator station 30 also includes a control support arm 36 which is secured to a rearward portion of the frame 12. Control support arm 36 extends forwardly and around the seat 32 such that a steering wheel 38 is located directly in front of the operator and a control module 40 for housing control elements such as control switches and indicators is within view and reach of the operator. Located on control support arm 36 and adjacent to steering wheel 38 may be a communication panel which is operable for displaying mowing and operating instructions to the operator. Formed integral to frame 12 and associated with operator station 30 is a foot deck 44. Foot deck 44 is ergonomically angled for operator comfort and ease of reaching the drive pedal 46, brake pedal 48, and the reel mower activation switch 47. Seat 32 further may also include an assist handle 49 for assisting the operator on and off the mower 10.
Mower 10 also includes a steering mechanism 50 for rotating steerable rear wheel 16 of mower 10. Steerable rear wheel 16 is mounted to a pair of brackets 52 secured to a U-shaped yoke member 54. U-shaped yoke member 54 includes spindle 56 which is journally supported within a sleeve which is in turn secured to frame 12. Spindle 56 projects upwardly through frame 12 allowing for a steering sprocket 58 to be secured thereto. Steering sprocket 58 has a plurality of teeth 60 formed along its circumference for engaging a plurality of complimentary teeth formed in a shaft 62 projecting from steering motor 64 secured to the frame 12. Steering motor 64 enables the projection and retraction of shaft 62 which, through engagement of teeth 60 induces rotation of steering sprocket 58, thereby causes rotation of steerable rear wheel 16. Steering motor 64 may be an electrically or hydraulically actuated device which receives control commands from an electronic (or hydraulic) controller to cause projection or retraction of shaft 62. For example, steering motor 64 may be an electric motor operating a ball screw mechanism or a self-contained hydraulic cylinder integral with shaft 62.
Motor controller 85 receives the output voltage provided by battery pack 81 and modulates the voltage input to motor 87. In this manner, motor controller 85 modulates the output of motor 87 by modulating the voltage input to motor 87. Motor controller 85 operates in conjunction with an electronic control circuit 93, which determines the desired mower speed and varies the output of motor 87 using a control signal input to motor controller 85 in order to vary the output of motor 87. Electronic control circuit 93 receives input signals through a pair of potentiometers 95 and 97 which are controlled by operator foot pedals 99 and 101, respectively. When the operator (not shown) presses operator foot pedal 99 (the brake pedal), a change in the position of potentiometer 95 results in a variation of the signal input to electronic control circuit 93. Similarly, when the operator depresses operator foot pedal 101 (the drive pedal), a change in the position of potentiometer 97 results in a variation of the signal input to electronic control circuit 93. Electronic control circuit 93 determines the desired output of motor 87 in accordance with the input signals and generates a control signal to motor controller 85. Motor controller 85 in turn varies the output voltage applied to motor 87 in accordance with the received control signal.
Electronic control circuit 93 also receives input from operator control panel 103, which is analogous to the operator control panels mentioned with respect to
With reference to
The power source 24, as described with respect to
The angled channels 82 and 84 are separated by a distance sufficient to accommodate the power source 24 and the attached frame 96, but are preferably also spaced to limit movement of the power source 24 perpendicularly to the direction of angled channels 82 and 84. Angled channels 82 and 84 include pins or keys 100 inserted in holes 102 at preferably each end of angled channels 82 and 84 to limit movement of power source 24 relative to mower 10.
The change stand 110 is preferably a rigid structure having a plurality of supporting legs 128 having sufficient strength to support the weight of at least two power sources. A plurality of cross-members 130 preferably provide additional rigidity to the overall structure of the change stand 110. The change stand 110 also includes a top surface 132 preferably formed of a material to facilitate sliding a power source and its supporting frame over the top surface 132 of the change stand 110. The top surface 132 may also optionally include rollers or inverted casters to further facilitate manipulation of the power sources. Change stand 110 also preferably includes a side guard 134 which maintains the power sources within the top surface 132 of change stand 110.
In order to replace a depleted power source 112 with a fully energized power source 126, the grounds maintenance crew must first deliver a power source to the change stand 110. A towable trailer 140 provides a vehicle to deliver the energized power source 126 to the change stand 110.
In operation, the towable trailer 140 is aligned so that when the leafs 148 are placed in a lowered position, they substantially align with changing plank 114. After the leafs 148 are lowered, the power source 150 may then be moved to the change stand 110. Once on the change stand 110, the power source 150, the operator positions energized power source 150, the depleted power source on change stand 110 may then be transferred onto towable trailer 140. Thus, the energized power source may be exchanged with the depleted power source so that the depleted power source may be returned to a specific location for replenishing.
It will be understood by one skilled in the art that various modifications of towable trailer 140 may be made. For example, towable trailer 140 need not include leafs 148. Transfer may be effected by aligning, for example, the rear end of towable trailer 140 with the changing plank 114 and switchably changing power sources off the rear of towable trailer 140. Further, it will be understood by one skilled in the art that towable trailer 140 may also function as a mobile change stand. That is, towable trailer 140 may be disposed in various locations where stationary change stand 110 would otherwise be disposed. Leafs 148 may then be lowered to a downward position and may function similarly to the top surface 132 of change stand 110. In this particular embodiment, the plank may be adapted for storage on the towable trailer 140 during transportation and attached to the rear portion of towable trailer 140 when the trailer is placed in position for power source interchange.
In a second embodiment of a trailer adapted for direct interchange,
The battery pack 192 is disposed within a rack 230. The rack 230 has a lower platform 232 which supports the individual batteries 234. An upper rail 236 of the rack 230 provides upper stability to the individual batteries 234 of the battery pack 192. Disposed beneath the lower platform 232 is a plurality of rollers 238 attached to the lower platform 232. The rollers 238 facilitate movement of the battery pack 192 over the top surface of frame 208. Further, the mower 190 includes on either side of the frame 208, where the battery pack 192 is located, gates 240 which retained the battery pack 192 laterally on the mower 190. The gates 240 may be lowered to enable the transfer of a battery pack onto and off of the mower 190.
The lower portion of scissor jack 280 includes a pair of rollers 284 which translate within lower horizontal track 286. Similarly, a pair of vertical tracks 288 accommodates rollers 290 which translate within the track 288. The rollers 290 are attached to the upper shelf 270 and lower shelf 272 so that the upper and lower shelves remain horizontally stable during the raising and lowering operation.
In operation, the operator positions the mower 190 adjacent to the battery change rack 260. One of the upper shelf 270 or lower shelf 272 preferably does not contain a battery pack. The empty shelf is then positioned in substantial vertical alignment with the upper surface of battery frame 208. The operator then transfers the battery pack 192 from the mower 190 onto the empty shelf (272 as shown in
In a first configuration of the present embodiment, the trailer 302 includes a pair of wheels 316 supporting the main platform 318. A screw jack 320 having a crank handle 322 may be operated to support the trailer 302 when disengaged from the mower 300. Following engagement of the tow bar 304 with the hitch 306, the screw jack 320 may be raised to lower the hitch 306 onto the ball 305 to enable transport of the trailer 302. A battery pack 324 includes a plurality of batteries 326 housed in a frame 328 which rests on main platform 318. The batteries may be interchanged using one of the methods described herein. The battery pack 324 is placed on a lower shelf 330 of main platform 318. A motor/generator set 334 rests upon the top shelf 332 of the trailer 302. The motor/generator set 334 includes an internal combustion motor 336 which provides mechanical input to one of a motor or generator 338 converts the mechanical input energy into electrical energy to drive the mower 300. The internal combustion motor 336 receives fuel from a fuel source such as a fuel tank 340 and preferably includes a muffler to abate noise generated by the internal combustion motor 336. The motor/generator set 334 also includes a gel cell 342 to provide electrical input for starting the internal combustion motor 336. The motor/generator set 334 operates in conjunction with battery pack 324 to provide driving electrical energy to the mower 300. Further, the motor/generator set 334 preferably provides sufficient electrical energy to charge battery pack 324 when the electrical output of the battery pack 324 drops below a predetermined level.
In another embodiment of the present invention, a second battery pack 324 may substitute for the motor/generator set 334 on the top shelf 332 of the trailer 302. A dual battery pack configuration has particular appeal when operating in golf courses in residential areas which require extremely low noise levels. Thus, the all electric mower 300 driven by dual battery packs 324 presents a particularly quiet option for operation of the mower 300. The trailer 302 may also include a vented cover 344 to prevent dirt, moisture, and other debris from entering the interior of the trailer 302.
In yet another embodiment, the ball 305 and the hitch 306 also connect electrically to indicate a positive connection therebetween. In this manner, the ball 305 and hitch 306 cooperate so that a good mechanical connection must be established prior to establishment of an electrical connection. The electrical connection may then be checked prior to enabling operation of the mower 300. This provides an electrical interlock mechanism to allow for safe operation of the mower.
In still another embodiment of the present invention, a motor/generator set similar to that shown at 334 in
It should be noted by one skilled in the art that the trailers of
Each battery tray 374, 376, and 378 includes a single conductor having two terminal connections A7 and A8 and B7 and B8 and C7 and C8, respectively. The single conductors enable the controller to verify a positive electrical connection between connector 384 and a mating connector. By verifying a current flow or voltage potential across each connector pair A7 and A8, A7 and A8, and A7 and A8, the system can verify an electrical connection between connector 384 and a mating connector to help ensure safe operation of the vehicle. It should be noted that while the embodiment of
In operation, when mowing around the golf course, and in particular the fairways, a towed battery trailer arrangement as described in
Following the completion of mowing at the third hole, the operator proceeds to battery drop site two where the battery pack on the mower, which is in a discharged state, is replaced with a fresh, fully charged battery pack from the trailer dispatch to battery drop site two. Upon replacement of the discharged battery with a fully charged battery pack, the operator then proceeds to mow fairways four, five, and six. After mowing the sixth fairway, the operator proceeds to battery drop site one where the battery pack installed at battery drop site two, which will now be in a discharged state, is replaced with a fully charged battery pack found at battery drop site one. The operator then proceeds to mow the fairways of the seventh, eighth, and ninth holes. After completion of the ninth hole, the operator then proceeds to the service building.
Alternatively, after completion of mowing the ninth hole, the operator may then proceed along the predetermined path, indicated by a dotted line, to battery drop site two where the towable trailer found at battery drop site two is attached to the trailer hitch found at the rear of the mower. The operator then proceeds to move the mower and the attached battery trailer to battery drop site one where the trailer found at battery drop site one is hitched to the trailer hitch found at the rear of the towable trailer hitch to the fairway mower at battery drop site one. The operator then tows both towable battery trailers back to the service building where all three battery packs, which are in a currently discharged state, can be recharged in anticipation of the next day's operation. Of course, it will be understood by one skilled in the art that the following procedure may vary in accordance with the mowing to occur, the discharge rate of the batteries, the number of holes on the golf course, and the length of the holes on the golf course, as well as several other factors. The above description is primarily an exemplary description of one particular implementation of the above-described operation.
The foregoing detailed description shows that the preferred embodiments of the present invention are well suited to fulfill the objects above-stated. It is recognized that those skilled in the art may make various modifications or additions to the preferred embodiments chosen to illustrate the present invention without departing from the spirit and proper scope of the invention. For example, drive motors, reel motors, lift motors and steering motors of different voltages may be utilized, and the taps into the battery packs may be changed accordingly. Further, gear boxes may be used between the reels and reel motors if desired, and the number of batteries in the battery pack may be varied as needed.
While the present invention has been discussed with respect to riding mowers having a reel-type mowing heads, those skilled in the art will appreciate that it may be applied to electrically-powered riding mowers having multiple rotary mowing heads. In addition, the electrical control systems, generator set arrangements, and virtually all other aspects of the present invention may be used in connection with other turf care equipment used to tend large expanses of grass. For example, electrically-powered riding sprayers, aerators, dethatchers, and other equipment which would be beneficially operated in a pollution-free way with extremely low noise would benefit by the systems and structures of the present invention. In other words, except for the working tool being a mowing head, most such equipment can be readily adapted to utilize the various aspects of the present invention. Thus, the term “turf care machine” or “turf care equipment” if used in the claims below is to be understood to extend to all such forms of power-consuming equipment when arranged to be operated and/or driven using electrical motors and/or electrically-powered work-producing devices. Accordingly, it is to be understood that the protection sought and to be afforded hereby should be deemed to extend to the subject matter as defined by the appended claims, including all fair equivalents thereof.