U.S. patent application number 11/906546 was filed with the patent office on 2008-04-17 for hybrid electric device.
Invention is credited to Delbert E. Lucas, Justin Lucas, Ryan J. Lucas, Rick Nuchols.
Application Number | 20080086997 11/906546 |
Document ID | / |
Family ID | 39303203 |
Filed Date | 2008-04-17 |
United States Patent
Application |
20080086997 |
Kind Code |
A1 |
Lucas; Delbert E. ; et
al. |
April 17, 2008 |
Hybrid electric device
Abstract
A device includes a housing configured with a working element.
The device further includes a motor configured for urging motion of
the working element. The device further includes a power control
module. The power control module is configurable for being in
electrical connection with at least one of the motor, a first power
source configuration and a second power source configuration. The
first power source configuration is configurable for being
electrically connected to a battery assembly having a DC power
output. The second power source configuration is configurable for
being electrically connected to a power inverter, the power
inverter configured for receiving an AC power and further
configured for outputting a DC power to the second power source
configuration. The motor receives power via the power control
module from the first power source configuration and/or the second
power source configuration.
Inventors: |
Lucas; Delbert E.; (Bowling
Green, KY) ; Lucas; Justin; (Stone Mountain, GA)
; Lucas; Ryan J.; (Atlanta, GA) ; Nuchols;
Rick; (Loveland, OH) |
Correspondence
Address: |
SUITER SWANTZ PC LLO
14301 FNB PARKWAY
SUITE 220
OMAHA
NE
68154
US
|
Family ID: |
39303203 |
Appl. No.: |
11/906546 |
Filed: |
October 1, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11899616 |
Sep 5, 2007 |
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11906546 |
Oct 1, 2007 |
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11670932 |
Feb 2, 2007 |
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11899616 |
Sep 5, 2007 |
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11550476 |
Oct 18, 2006 |
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11670932 |
Feb 2, 2007 |
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11550104 |
Oct 17, 2006 |
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11550476 |
Oct 18, 2006 |
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Current U.S.
Class: |
56/10.6 ; 310/66;
310/89; 318/441 |
Current CPC
Class: |
A01D 34/78 20130101;
A01D 69/025 20130101 |
Class at
Publication: |
056/010.6 ;
310/066; 310/089; 318/441 |
International
Class: |
H02K 7/14 20060101
H02K007/14; A01D 34/37 20060101 A01D034/37; H02P 4/00 20060101
H02P004/00; H02K 5/00 20060101 H02K005/00 |
Claims
1. A device, comprising: a housing configured with a working
element; a motor configured for urging motion of the working
element; a power control module, the power control module
configurable for being in electrical connection with at least one
of the motor, a first power source configuration and a second power
source configuration, the first power source configuration
configurable for being electrically connected to a battery assembly
having a Direct Current (DC) power output, the second power source
configuration configurable for being electrically connected to a
power inverter, the power inverter configured for receiving an
Alternating Current (AC) power and further configured for
outputting a DC power to the second power source configuration,
wherein the motor receives power via the power control module from
at least one of the first power source configuration and the second
power source configuration.
2. The device as claimed in claim 1, wherein the device is an
electric lawnmower.
3. The device as claimed in claim 1, wherein the power control
module is manually operable via a power selection switch for
selecting between the first power source configuration and the
second power source configuration.
4. The device as claimed in claim 3, wherein the power control
module includes an automatic power selection configuration for
automatically selecting the second power source configuration when
the second power source configuration receives DC power from the
power inverter.
5. The device as claimed in claim 4, wherein the automatic power
selection configuration is overridable by manual selection via the
manually operable power selection switch.
6. The device as claimed in claim 1, wherein the power control
module further includes a both configuration, wherein when the both
configuration is selected, the motor receives power from both the
first power source configuration and the second power source
configuration.
7. The device as claimed in claim 1, wherein the power inverter is
a rectifier and filter combination.
8. The device as claimed in claim 1, wherein the power inverter
includes a step down controller.
9. The device as claimed in claim 8, wherein the step down
controller includes a voltage rectifier and a pulse width
modulator.
10. The device as claimed in claim 1, wherein the battery assembly
has a normal output voltage of 60 volts.
11. The device as claimed in claim 1, wherein the power inverter
receives an AC input of 120 volts, and outputs a DC output of 60
volts.
12. The device as claimed in claim 1, wherein the battery assembly
includes a stack of DC batteries connected in series.
13. The device as claimed in claim 1, wherein the battery assembly
is removable from the device, and is chargeable at a location
separate from the device.
14. The device as claimed in claim 1, wherein the battery assembly
is chargeable while on board the device and during the operation of
the device.
15. The device as claimed in claim 3, wherein the power selection
switch is positioned on the housing.
16. The device as claimed in claim 3, wherein the power selection
switch is positioned on a handle of the device.
17. A device, comprising: a housing configured with a working
element; a motor configured for urging motion of the working
element; a power control module, the power control module
configurable for being in electrical connection with at least one
of the motor, a first power source configuration and a second power
source configuration, the first power source configuration
configurable for being electrically connected to a battery assembly
having a DC power output, the second power source configuration
configurable for being electrically connected to a power inverter,
the power inverter configured for receiving an AC power and further
configured for outputting a DC power to the second power source
configuration, wherein the motor receives power via the power
control module from at least one of the first power source
configuration and the second power source configuration, wherein
the power control module further includes a boost conserve switch
including a conserve mode for supplying a first voltage to the
motor when the boost conserve switch is established in the conserve
mode and a boost mode for supplying a second voltage to the motor
when the boost conserve switch is established in the boost mode,
the first voltage being less than the second voltage.
18. The device as claimed in claim 17, wherein the power control
module is configured for controlling motor speed by supplying at
least one of the first voltage and the second voltage when the
boost conserve switch is established in at least one of the
conserve mode and the boost mode.
19. The device as claimed in claim 17, wherein motor speed when the
first voltage is supplied is below 14,000 feet per minute blade
speed, and motor speed when the second voltage is supplied is above
15,000 feet per minute blade speed.
20. The device as claimed in claim 17, wherein the boost conserve
switch is configured for at least one of establishing an electrical
connection with an auxiliary battery and terminating an electrical
connection with an auxiliary battery.
21. The device as claimed in claim 17, wherein the boost conserve
switch is configured for at least one of increasing DC power output
of the power inverter and decreasing DC power output of the power
inverter.
22. The device as claimed in claim 17 wherein the boost conserve
switch is configurable for at least one of establishing an
electrical connection with the battery assembly and terminating an
electrical connection with the battery assembly.
23. A device, comprising: a housing configured with a first working
element and a second working element; a first motor configured for
urging motion of the first working element; a second motor
configured for urging motion of the second working element; a power
control module configurable for being in electrical connection with
at least one of the first motor, the second motor, a first power
source configuration and second power source configuration, the
first power source configuration configurable for being
electrically connected to a battery assembly having a DC power
output, the second power source configuration configurable for
being electrically connected to a power inverter, the power
inverter configured for receiving an AC power and further
configured for outputting a DC power to the second power source
configuration, wherein the first motor and the second motor are
configured for receiving power via the power control module from at
least one of the first power source configuration and the second
power source configuration.
24. The device as claimed in claim 23, wherein the first and the
second motors are electrically connected in a parallel
configuration.
25. The device as claimed in claim 23, wherein the first and the
second motors are electrically connected in a series
configuration.
26. The device as claimed in claim 23, wherein the power control
module further includes a circuit setting switch having a first
circuit setting and a second circuit setting, the circuit setting
switch allowing the first motor and the second motor to be
electrically connected in a parallel configuration when the circuit
setting switch is established at the first circuit setting, the
circuit setting switch further allowing the first motor and the
second motor to be electrically connected in a series configuration
when the circuit setting switch is established at the second
circuit setting.
27. The device as claimed in claim 26, wherein the circuit setting
switch is a three pole double throw switch configured for
electrically connecting with at least one of the first power source
configuration, the second power source configuration, the first
motor and the second motor, the circuit setting switch being
further configured for automatically selecting the first circuit
setting when the circuit setting switch is connected to the first
power source configuration, the circuit setting switch being
further configured for automatically selecting the second circuit
setting when the circuit setting switch is connected to the second
power source configuration.
28. The device as claimed in claim 23, wherein the power control
module further includes a boost conserve switch including a
conserve mode for supplying a first voltage to the first motor and
the second motor when the boost conserve switch is established in
the conserve mode and a boost mode for supplying a second voltage
to the first motor and the second motor when the boost conserve
switch is established in the boost mode, the first voltage being
less than the second voltage.
29. A device, comprising: a housing configured with a working
element; a motor configured for urging motion of the working
element; a power control module, the power control module
configurable for being in electrical connection with at least one
of the motor, a first power source configuration and a second power
source configuration, the first power source configuration
configurable for being electrically connected to a battery assembly
having a Direct Current (DC) power output, the second power source
configuration configurable for being electrically connected to a
power inverter, the power inverter configured for receiving an
Alternating Current (AC) power and further configured for
outputting a DC power to the second power source configuration; and
a switch for selecting between a first mode for charging the
battery assembly when the power control module is receiving AC
power and a second mode for not charging the battery, wherein the
motor receives power via the power control module from at least one
of the first power source configuration and the second power source
configuration.
30. A device, comprising: a housing configured with a working
element; a motor configured for urging motion of the working
element; the motor mounted on a deck having a first rigidity; and a
reinforcing framework having a second rigidity mounted to the
deck.
31. The device as claimed in claim 30, wherein the deck comprises
at least one of plastic and fiberglass.
32. The device as claimed in claim 31, wherein the deck comprises
reinforcing ribs.
33. The device as claimed in claim 30, wherein the reinforcing
framework comprises steel.
34. The device as claimed in claim 33, wherein the reinforcing
framework comprises a substantially tubular shape.
35. The device as claimed in claim 30, further comprising: a
handle; and at least one axle tower positioned on the deck, wherein
the handle is in supportive contact with the axle towers.
36. The device as claimed in claim 35, further comprising: a
controller mounted on the deck in electric connection with the
motor, wherein the motor, the controller, the axle towers and the
deck form a box structure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part
application and claims priority under 35 U.S.C. .sctn. 120 to U.S.
patent application Ser. No. 11/899,616 entitled: Hybrid Electric
Lawnmower filed Sep. 5, 2007, (pending) which is a
continuation-in-part application claiming priority under 35 U.S.C.
.sctn. 120 to U.S. patent application Ser. No. 11/670,932 entitled:
Hybrid Electric Lawnmower filed Feb. 2, 2007, (pending) which is a
continuation-in-part application claiming priority under 35 U.S.C.
.sctn. 120 to U.S. patent application Ser. No. 11/550,476 entitled:
Hybrid Electric Lawnmower Having Dual Power Supply filed Oct. 18,
2006, (pending) which is a continuation-in-part application
claiming priority under 35 U.S.C. .sctn. 120 to U.S. patent
application Ser. No. 11/550,104 entitled: Hybrid Electric Lawnmower
filed Oct. 17, 2006 (pending). U.S. patent application Ser. Nos.
11/899,616, 11/670,932, 11/550,476 and 11/550,104 are hereby
incorporated by reference in their entireties herein. Further, U.S.
patent application entitled Hybrid Electric Device filed Oct. 1,
2007 and having Express Mail Mailing Label Number EM 005738901 US
is also hereby incorporated by reference its entirety herein.
FIELD OF THE INVENTION
[0002] The present invention generally relates to the field of
hybrid electric devices, and more particularly to a hybrid electric
device having a boost/conserve power feature and a dual mode power
supply for providing power to an electric motor.
BACKGROUND OF THE INVENTION
[0003] Power tools are frequently utilized for lawn and property
maintenance operations in and around various properties. The tools
may be commonly utilized for operations that require a motor, such
as operations requiring the rotational actuation of a working
element, such as a cutting blade and/or an impeller. One such power
tool is a lawnmower. Another such tool is a snow blower. Lawnmowers
typically utilize a rotating cutting blade, while snow blowers
typically utilize a rotating impeller/fan. Some power tools may be
operated from AC mains, such as power supplied by a utility company
or from an AC generator. Other power tools may be operated
utilizing a battery.
SUMMARY OF THE INVENTION
[0004] Accordingly, an embodiment of the present invention is
directed to a device including: a housing configured with a working
element; a motor configured for urging motion of the working
element; a power control module, the power control module
configurable for being in electrical connection with at least one
of the motor, a first power source configuration and a second power
source configuration, the first power source configuration
configurable for being electrically connected to a battery assembly
having a Direct Current (DC) power output, the second power source
configuration configurable for being electrically connected to a
power inverter, the power inverter configured for receiving an
Alternating Current (AC) power and further configured for
outputting a DC power to the second power source configuration,
wherein the motor receives power via the power control module from
at least one of the first power source configuration and the second
power source configuration.
[0005] An additional embodiment of the present invention is
directed to a device, including: a housing configured with a
working element; a motor configured for urging motion of the
working element; a power control module, the power control module
configurable for being in electrical connection with at least one
of the motor, a first power source configuration and a second power
source configuration, the first power source configuration
configurable for being electrically connected to a battery assembly
having a DC power output, the second power source configuration
configurable for being electrically connected to a power inverter,
the power inverter configured for receiving an AC power and further
configured for outputting a DC power to the second power source
configuration, wherein the motor receives power via the power
control module from at least one of the first power source
configuration and the second power source configuration, wherein
the power control module further includes a boost conserve switch
including a conserve mode for supplying a first voltage to the
motor when the boost conserve switch is established in the conserve
mode and a boost mode for supplying a second voltage to the motor
when the boost conserve switch is established in the boost mode,
the first voltage being less than the second voltage.
[0006] A further embodiment of the present invention is directed to
a device, including: a housing configured with a first working
element and a second working element; a first motor configured for
urging motion of the first working element; a second motor
configured for urging motion of the second working element; a power
control module configurable for being in electrical connection with
at least one of the first motor, the second motor, a first power
source configuration and second power source configuration, the
first power source configuration configurable for being
electrically connected to a battery assembly having a DC power
output, the second power source configuration configurable for
being electrically connected to a power inverter, the power
inverter configured for receiving an AC power and further
configured for outputting a DC power to the second power source
configuration, wherein the first motor and the second motor are
configured for receiving power via the power control module from at
least one of the first power source configuration and the second
power source configuration.
[0007] A further embodiment of the present invention is directed to
a device, including: a housing configured with a working element; a
motor configured for urging motion of the working element; a power
control module, the power control module configurable for being in
electrical connection with at least one of the motor, a first power
source configuration and a second power source configuration, the
first power source configuration configurable for being
electrically connected to a battery assembly having a Direct
Current (DC) power output, the second power source configuration
configurable for being electrically connected to a power inverter,
the power inverter configured for receiving an Alternating Current
(AC) power and further configured for outputting a DC power to the
second power source configuration; and a switch for selecting
between a first mode for charging the battery assembly when the
power control module is receiving AC power and a second mode for
not charging the battery, wherein the motor receives power via the
power control module from at least one of the first power source
configuration and the second power source configuration.
[0008] A further embodiment of the present invention is directed to
a device, including: a housing configured with a working element; a
motor configured for urging motion of the working element; the
motor mounted on a deck having a first rigidity; and a reinforcing
framework having a second rigidity mounted to the deck.
[0009] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not necessarily restrictive of the
invention as claimed. The accompanying drawings, which are
incorporated in and constitute a part of the specification,
illustrate an embodiment of the invention and together with the
general description, serve to explain the principles of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The numerous advantages of the present invention may be
better understood by those skilled in the art by reference to the
accompanying figures in which:
[0011] FIG. 1 is an isometric view of a hybrid mower;
[0012] FIG. 2 is another isometric view of the hybrid mower
illustrated in FIG. 1;
[0013] FIG. 3 is a perspective view of the hybrid mower illustrated
in FIG. 1;
[0014] FIG. 4 is another perspective view of the hybrid mower
illustrated in FIG. 1;
[0015] FIG. 5 is a side elevation view of the hybrid mower
illustrated in FIG. 1;
[0016] FIG. 6 is a rear elevation view of the hybrid mower
illustrated in FIG. 1;
[0017] FIG. 7A is a top plan view of the hybrid mower illustrated
in FIG. 1;
[0018] FIG. 7B is a bottom view of the hybrid mower illustrated in
FIG. 1;
[0019] FIG. 8 is a perspective view of the hybrid mower illustrated
in FIG. 1;
[0020] FIG. 9 is a partial cross-sectional side elevation view of
the hybrid mower illustrated in FIG. 1;
[0021] FIG. 10 is an isometric view of the hybrid mower illustrated
in FIG. 1, wherein the hybrid mower is operated via a battery;
[0022] FIG. 11 is an isometric view of the hybrid mower illustrated
in FIG. 1, wherein the hybrid mower is operated via AC current;
[0023] FIG. 12 is an exploded isometric view of the hybrid mower
illustrated in FIG. 1;
[0024] FIG. 13 is an exploded isometric view illustrating a
removable battery and a housing cover for the hybrid mower
illustrated in FIG. 1;
[0025] FIG. 14 is an exploded isometric view illustrating a control
unit for the hybrid mower illustrated in FIG. 1;
[0026] FIG. 15 is an exploded isometric view illustrating a deck
assembly for the hybrid mower illustrated in FIG. 1;
[0027] FIG. 16 is an isometric view illustrating a height
adjustment assembly for the hybrid mower illustrated in FIG. 1;
[0028] FIG. 17 is side elevation view of the height adjustment
assembly illustrated in FIG. 16;
[0029] FIG. 18 is an isometric view illustrating a hybrid mower,
wherein the hybrid mower includes a cord holder;
[0030] FIG. 19 is an isometric view illustrating a hybrid mower,
wherein the hybrid mower includes another cord holder;
[0031] FIG. 20 is an isometric view illustrating a hybrid mower in
a stowage position;
[0032] FIG. 21 is an exploded isometric view illustrating the
hybrid mower shown in FIG. 20, wherein the hybrid mower is shown in
a shipping configuration;
[0033] FIG. 22 is an isometric view of the hybrid mower illustrated
in FIG. 1;
[0034] FIG. 23 is a circuit diagram of one option of a battery
assembly for use with the hybrid mower illustrated in FIG. 1;
[0035] FIG. 24 is a circuit diagram of one option of a power
control circuit for use with the hybrid mower illustrated in FIG.
1;
[0036] FIG. 25 is a circuit diagram of one option of the power
inverter and hybrid control illustrated in FIG. 24 for use with the
hybrid mower illustrated in FIG. 1;
[0037] FIG. 26 is a circuit diagram illustrating one option of the
power control circuit for use with the hybrid mower illustrated in
FIG. 1;
[0038] FIG. 27 is a circuit diagram illustrating an alternative
option of the power control circuit for use with the hybrid mower
illustrated in FIG. 1;
[0039] FIG. 28 is a circuit diagram illustrating still an
alternative option of the power control circuit for use with the
hybrid mower illustrated in FIG. 1;
[0040] FIG. 29A is a top plan view of a hybrid mower including two
motors and two cutting blades;
[0041] FIG. 29B is a bottom view of the hybrid mower illustrated in
FIG. 29 A;
[0042] FIG. 30 is a circuit diagram illustrating one option of the
power control circuit for use with the hybrid mower illustrated in
FIGS. 29A and 29B;
[0043] FIG. 31 is a circuit diagram illustrating an alternative
option of the power control circuit for use with the hybrid mower
illustrated in FIGS. 29A and 29B;
[0044] FIG. 32 is a cross-sectional side view of a motor
assembly;
[0045] FIG. 33 is a circuit diagram illustrating a parallel
configuration utilized by the motor illustrated in FIG. 32;
[0046] FIG. 34 is a circuit diagram illustrating a parallel
configuration utilized by the motor illustrated in FIG. 32;
[0047] FIG. 35 is a circuit diagram illustrating one option of the
power control circuit for use with the hybrid mower utilized the
motor illustrated in FIG. 32;
[0048] FIG. 36A is a partial isometric view illustrating a hybrid
mower, wherein a battery compartment is in a closed
configuration;
[0049] FIG. 36B is a partial isometric view of the hybrid mower
illustrated in FIG. 36A, wherein the battery compartment is in an
open configuration;
[0050] FIG. 37 is a top plan view of a power selection switch;
[0051] FIG. 38 is a partial cross-sectional side elevation view of
a hybrid mower, wherein an airflow path is illustrated;
[0052] FIG. 39 is a partial isometric view of a hybrid mower
illustrating a lever for a height adjustment assembly;
[0053] FIG. 40 is a circuit diagram of another option for the power
inverter and hybrid control illustrated in FIG. 24 for use with the
hybrid mower illustrated in FIG. 1;
[0054] FIG. 41 is an isometric view of a hybrid snow blower;
and
[0055] FIG. 42 is graphical depiction which depicts a relationship
between mower load, voltage level, power consumption and blade
speed in accordance with an exemplary embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0056] Reference will now be made in detail to the presently
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings.
[0057] A hybrid electric device is described herein and set forth
in the claims and is partially depicted in the perspective view of
FIG. 1 wherein an exemplary embodiment of a hybrid mower 10 is
shown. The hybrid mower 10 includes a deck 50 with an outwardly
extending handle including an upper handle 55a and a lower handle
55b. Positioned on top of the deck 50 is a control box 24 including
a controller and at least one power selection switch 21. The deck
50 further includes a number of features including, but not limited
to, the power control and supply described herein as well as a DC
motor, a cutting component housing including at least one blade
(cutting component), and other necessary features for making the
electric lawnmower described herein operable to function as
desired. Such function and structure includes the DC motor for
driving the blade, the DC motor being powered by alternative power
supplies (power source configurations) which may include 120 VAC
line voltage or DC power supply such as a battery assembly 52. The
motor drives the blade, while the power control system/power supply
system of the hybrid electric mower allows the user to select the
power source whether it be AC power supply or DC power supply. In
either selection, the power control system of the electric mower
provides adequate voltage to the motor. Further, a selection is
available for the user of the present embodiment to drive the motor
in either conserve or boost mode. Conserve mode utilizes less power
from the power source than boost mode, thereby increasing run time
for each full battery charge under such selection, should the DC
operation mode be selected. It is understood that conserve and
boost mode may also be operable in AC operation mode.
[0058] Further, the motor may be designed as a dual voltage motor
which has the capability to operate on two different DC voltages,
such as a motor as described in U.S. Pat. No. 6,172,437. In one
embodiment, the dual voltage motor utilizes two separate
commutators on a single armature. Each commutator connects to one
set of windings (coils) that are separated from the other. Each
commutator is also in electric contact with a corresponding set of
brushes. The two sets of brushes may be selectively configured
through the use of a user selection switch which reconfigures the
two sets of coils on the motor from series connectivity, for higher
voltage source such as rectified line voltage, to parallel
connectivity, for a lower voltage source such as a battery
pack.
[0059] In this dual voltage motor configuration, if the higher
voltage is approximately twice the potential of the lower voltage,
the power supply will provide substantially the same voltage
potential across a first and a second commutator on the electric
motor. For example if the mower is connected to a standard AC power
source of 120 VAC, a rectifier may rectify the voltage to about 120
VDC (a higher voltage source). In such case, a series configuration
will provide each set of coils about 60 VDC. Alternatively, the
mower may be connected to a 60 VDC battery pack (a lower voltage
source). In such case, a parallel configuration will provide each
set of coils about 60 VDC also. Substantially the same voltage
provided to the sets of coils in both higher and lower voltages
results in substantially the same revolutions-per-minute or
rounds-per-minute (RPM) of the motor. In this manner, the
dual-voltage lawnmower may be capable of executing speed control
over the motor and the cutting blade without the utilization of an
electronic controller. This may represent a significant cost
benefit to a consumer. In one specific embodiment, the lack of a
controller may represent a cost savings of approximately ten
percent. It will be appreciated that the number of windings in the
motor may vary and/or the diameter of wires including the windings
may vary.
[0060] It is understood that alternative designs of the mower may
be employed without departing from the scope and spirit of the
present invention. For example, in one embodiment, the mower
utilizes a second electric motor in order to increase the cutting
width of the electric lawn mower without increasing the blade
diameter. Moreover, it will be appreciated that in addition to
permanent magnet DC motors, many other various types of motors may
be utilized with the present invention. These motors may include,
but are not limited to, a universal motor, a brushless DC motor, a
switched reluctance motor, a stepper motor, and/or an induction
motor.
[0061] Referring generally to FIGS. 1 through 11. A hybrid mower
with a boost conserve feature of the present embodiment is
depicted. A plurality of wheels support the deck 50 such that the
hybrid mower 10 may roll, be powered or be pushed over terrain
required to be cut by the blade 51. The specific configuration of
the hybrid mower 10 of the present embodiment, as depicted in FIG.
1, is not necessarily limiting in that the many structures and
switches which are depicted may be positioned on multiple surfaces
or in multiple positions on the hybrid mower 10 and thus, the
particular location and limitation of the depictions and structure
set forth are considered to be merely exemplary.
[0062] The hybrid mower 10 of the present embodiment incorporates
controls near the upper handle 55a such that they may be readily
accessible to the operator of the mower 10. A circuit breaker 28
having a key 28a is utilized to break the electrical connection to
the motor 56, hence stopping the blade 51, should the key 28a be
removed from a fully inserted position. Further, the circuit
breaker 28 also serves as a theft-prevention device as the motor
cannot be started without the key 28a. Also found located on the
upper handle 55a is a blade clutch handle 31. The blade clutch
handle 31 is utilized as an interlock handle switch to engage and
disengage the DC motor 56 from rotating the blade 51. The blade
clutch handle 31 must be operatively held in close relationship to
the upper handle 55a in order to engage the DC motor 56 and
correspondingly the blade 51. The blade clutch handle 31, when
placed and held in close relationship to the upper handle 55a,
engages an interlock handle switch as will be described herein
which may be a double throw switch, and which operates to act as a
user's dead man switch in order to disengage the DC motor if
released. Such features may be desirable in order to discontinue
rotation of the blade 51 upon release of a manually actuatable
handle within a limited and short period of time. Thus, the
interlock handle switch as depicted herein is integrated with the
blade clutch handle 31 and acts to operatively disengage the DC
motor and also cause resistive breaking (hard dynamic break) of
both the motor and the blade upon release of the handle 31.
[0063] The hybrid mower 10 of the present embodiment is designed to
be operated on either AC line voltage from an AC power source (such
as a wall plug or other AC source), or from a DC battery assembly
(pack) 52 which is mounted on the deck 50 or in close conductive
and operative relationship with the DC motor 56 depicted. The
hybrid mower 10 of the present embodiment is designed such that the
operator may operatively select functionality of the hybrid mower
10 and the motor 56 by either AC or DC power. When the mower 10 is
connected to an AC power source, as depicted in FIG. 8, an AC cord
22 is electrically connected to an AC receptacle 23 positioned on
the mower 10. The AC cord may be directly plugged into AC line
voltage which is typically 60 Hz 120 Volts. A battery pack 52
located on the deck 50 may provide DC power to the motor 56. The
battery pack 52 may be rechargeable.
[0064] Positioned on the mower 10 is also a power selection switch
21, as depicted in FIG. 37. In one specific embodiment, the power
selection switch 21 includes a battery charge indicator 83, a
plurality of power source selections 85, and a knob 86 for
selecting a specific power mode. In the present embodiment, the
power source selections 85 include a charge mode, a battery mode, a
battery boost mode, a 120V cord mode and a 120V boost mode. The
battery mode and the 120V cord mode are conserve modes, while the
battery boost mode and the 120V boost mode are boost modes. The
boost modes provide the functionality of increasing the voltage
provided to the DC motor 56 thereby increasing the rotational speed
of the blade 51 compared to conserve modes. When a boost mode is
selected, a boost conserve switch in the controller is turned on.
Conversely, when a conserve mode is selected, the boost conserve
switch in the controller is turned off. Selecting boost or conserve
mode may increase or decrease the voltage and thereby increase or
decrease the actual drain on the battery pack 52 or other power
supply due to the increased current provided to the DC motor 56. It
is understood that the power selection switch may have different
configuration. For example a plurality of buttons may be utilized
in place of a knob. Further, a different set of power source
selections may be provided.
[0065] In a present embodiment, the hybrid control system of the
hybrid mower 10 allows for the hybrid mower 10 to be powered from
regular household AC line voltage or from a DC voltage battery
pack. The battery pack may be designed to have a lower available
operating voltage than the average peak voltage of household
current. This arrangement may be provided in order to allow the
mower to run in a possible conservation mode in order to preserve
battery run time under less demanding grass conditions.
Alternatively, when the mower is plugged in to AC household current
or line voltage or when additional voltage is tapped from the
battery pack or from a battery associated with the battery pack,
the hybrid mower 10 of the present embodiment may selectively be
operated in a boost or power mode, the boost mode allowing for
mulching of taller grass or pick up of various debris, such as pine
cones, during operation.
[0066] Thus, for an example, when the hybrid mower 10 with power
boost conserve feature of the present embodiment is in
operation/being used for cutting relatively shorter grasses as
shown in FIG. 10, since such task requires less power, the battery
mode (a conserve mode) may be selected by the power selection
switch 21. The battery pack 52 may be brought in electrical
conductivity with the DC motor 56 and the conserve setting may
reduce the rotational speed of the blade 51 thereby decreasing the
rate of drain of the battery pack 52 and also increasing the run
and operation time of the hybrid mower 10 per charge. However,
should there be a need to increase the rotational speed of the
blade 51, the battery boost mode may be selected to increase the
voltage being supplied to the motor 56. It will be appreciated that
the battery boost mode may supply added voltage to the motor from a
secondary battery, and/or from any other auxiliary power source
included with and/or connected to the hybrid mower 10 as
needed.
[0067] Alternatively, the hybrid mower 10 with power boost conserve
feature of the present embodiment may be in operation while
connected to an AC power source, as shown in FIG. 11. Thus, for
cutting relatively taller grasses (as shown in FIG. 11), which
requires more power, the 120V boost mode may be selected by the
power selection switch 21. It will be appreciated that the 120V
boost mode may supply added voltage to the motor from the battery
pack 52, from a secondary battery, and/or from any other auxiliary
power source included with and/or connected to the hybrid mower 10
as needed. However, should there be a need to decrease the
rotational speed of the blade 51 (for example when operating over
an area where the grasses are generally shorter), the 120V mode (a
conserve mode) may be selected to decrease the voltage being
supplied to the motor 56 to conserve energy. Thus, the boost and
conserve feature as shown and depicted in the examples may be
integrated with either power selection of the AC power input line
or DC power input line to the DC motor 56. Further descriptions and
implementations of such examples will be described hereinafter.
[0068] In exemplary embodiments, the controller may include a speed
sensor for sensing a speed of the mower blade and adjusting the
voltage supplied to the motor to maintain the speed of the blade of
a substantially constant level. A relationship 2000 between mower
load, voltage level 2004, power consumption 2002 and blade speed
2008 for a specific embodiment is depicted in FIG. 42. As the load
of the mower increases (from IDLE towards FULL), the voltage level
2004 (hence the power consumption 2002) also increases in order to
maintain the blade speed 2008 of the substantially constant level
2006 (for example within 5% in this specific embodiment).
[0069] It may also be desirable in one of the present inventive
embodiments, to provide a battery pack 52 which is easily removable
from the lawnmower deck 50. The hybrid mower 10 of the present
embodiment may be used without the battery pack so as to be more
easily maneuverable in sloped areas due to the reduced weight of
not having the battery pack 52 installed. In one specific
embodiment, the total weight of the mower 10 with the battery
assembly is between approximately 60 lbs to approximately 70 lbs,
while the battery assembly weighs approximately 20 lbs. Therefore,
removing the battery assembly may reduce a considerable amount of
the weight. Additionally, the mower 10 of the present invention may
make it easier to stow/store the mower and charge the battery pack
52 separately or alternatively, may promote ease of charging the
battery when the mower 10 is still in operation (i.e., when AC
power is available). It may also be desirable that a battery cover
52a, as shown in FIG. 36A at a closed position and in FIG. 36B at
an open position, be provided to cover the location of the battery
pack 52. In addition, as illustrated in FIG. 22, the mower 10 with
the battery pack removed may be stored outside the garage 306,
hence saving space that would otherwise be used to store a
mower.
[0070] The DC motor 56 may be a permanent magnet type DC motor and
may be designed to receive power from the battery and/or from the
hybrid power controller which will be described herein. The DC
motor 56 may be provided to power the rotating blade 51 while
cutting vegetation and the motor 56 may act as a generator in order
to provide resistive breaking after deactivation of the interlock
handle switch described thereby providing a resistive load to stop
the blade quickly once the blade interlock handle 31 is released.
It is contemplated, as shown in FIG. 38, that the motor 56 may be
designed to further include a fan 91 to promote cooling of the DC
motor 56, thereby providing air circulation vent paths 93 across
the brushes and through the motor. For example, in a specific
embodiment, the motor promotes airflow up (relative to the ground
upon which the mower is supported) and across the heat sink. Then,
the airflow proceeds down through the motor (i.e., within the motor
housing). Alternative embodiments with multiple motors or with
multiple commutators selectively operating in series or in parallel
may also be provided.
[0071] As previously described, the blade 51 may be provided in
order to mulch or cut vegetation. Typical blade tip speeds may be
between approximately 16,000 to 19,000 ft. per minute during
non-cutting and between approximately 12,000 to 18,000 ft. per
minute during cutting of vegetation with a proportionate horsepower
rating for the DC motor of about 1.5. Higher speeds may be
indicated/attained when operating from AC line voltage while lower
speeds may be recognized/attained when operating off of Battery DC
voltage. Alternatively, in a low power or conservation mode, the
run time may be considerably longer with battery life expected to
be increased by 50% and with the speed of the DC motor 56
correspondingly decreasing to drive the blade 51 at approximately
14,000 ft. per minute blade speed as measured at the tip of the
blade. The various speeds of the blade 51 can correspond to a
plurality of voltage outputs from the hybrid power supply as
seen/detected/received by the DC motor 56. Namely, to provide
higher speed functionality of the blade, a voltage of 66V or 72V DC
may be presented to the DC motor with a 300 watt/hr batter charge
capacity. Alternatively, in conservation or low speed mode, which
may thereby correspond to higher battery pack run time duration or
less current draw from the power supply, the power consumption may
be significantly reduced by providing 60V or less to the DC motor
56. These various power consumption modes may be provided through
the use of the boost and conserve switch which, as can be seen from
the examples depicted herein, may be a single pole double throw
switch as shown in order to increase the voltage through the
various means depicted and described in the multiple examples
hereof.
[0072] Thus, when the mower 10 is in conservative mode, the
corresponding blade speed may be less than 15,000 ft. per minute
blade tip measurement and preferably at 14,000 ft. per minute blade
tip measurement or less thereby significantly increasing the
battery pack charge run time when the battery pack is in operation
and the power selection switch 21 is selected/positioned in the
battery mode. In such an instance, the 60 volts may be provided to
the DC motor by the battery pack 52, which may include a series of
five batteries connected in series, each of the batteries providing
12 volts. Alternatively, should the power selection switch 21 be
set to the battery boost mode, an additional or secondary battery
which may be integrated with or separated from the battery pack 52,
may be brought in series with the battery pack 52 power supply
thereby increasing the voltage to 66 or 72 volts, depending on
desirability and the blade speed at which the mower 10 is to be
operated.
[0073] The battery assembly may include a stack of DC batteries
connected in series. In one specific embodiment, as shown in FIG.
23, the battery assembly 700 includes a stack of five lead acid
five amp-hour 12V DC batteries 702. In this configuration the
voltage of the battery assembly may be around 60V. It will be
appreciated that when fully charged, the voltage of the battery
assembly 700 may be approximately 66V and, during battery
discharge, may be reduced to approximately 50V. Further, it will be
appreciated that as the battery discharges, the speed of the mower
blade may be reduced proportionally. For this reason, it is
contemplated that the speed of the mower blade may be set based on
the fully-charged voltage of the battery assembly and/or the
battery assembly and one or more other power sources, as utilized
in a power boosting configuration.
[0074] In a further embodiment, the battery assembly 700 may be
connected in series with an auxiliary battery 54 in a power
boosting configuration, through the control of the boost conserve
switch 26. The auxiliary battery 54 may be a five amp-hour 12V DC
battery. In this configuration, when in the power boosting mode
(boost conserve switch 26 is set to ON), the voltage of the battery
assembly and the auxiliary battery together may be around 72V. It
is understood that variations may be provided in the configuration
and implementation while running in DC mode for the battery pack
depicted herein as this example is provided merely for descriptive
purposes only and many other embodiments including bringing
batteries in parallel, series, or providing additional power
sources may be utilized.
[0075] While the example of the conserve and boost switch has been
provided for operation in DC mode, alternative embodiments which
may provide an increase in motor speed while running in AC mode
will also be described herein. Such embodiments may include
increasing the step down voltage from the power supply controller
as presented to the DC motor or alternatively bringing in series
the secondary battery while also operating in AC mode thereby
increasing the DC voltage presented to the motor and resulting in
an increase in rotational speed of the blade. Thus alternative
embodiments are shown and depicted wherein the power supply of the
present embodiment generates DC power to the motor and wherein the
boost or increased voltage may be derived from either the power
supply by various techniques, such as depicted, or by providing
additional voltage from the battery pack or secondary battery,
either of which may result in increased operational speed of the
motor and blade speed.
[0076] One other aspect of the present embodiment of the hybrid
mower 10 of the present embodiment is the ability to provide a user
selectable power supply to a DC motor driving the blade 51. In the
hybrid mower 10 of the present embodiment, a DC motor 56 is
provided to rotate blade 51 on the mower deck 50 due to its energy
use and supply characteristics. A user selectable alternative power
supply or power selection switch 21 is provided in order that the
DC motor 56 may be user switchable from power sources, namely from
an AC 120 volt 60 Hz power input representing line voltage should
an extension cord or line voltage be readily accessible, or
alternatively, to a battery pack DC voltage provided on board of
the mower, both power supplies selectable by the operator and both
power supplies driving the same motor mounted on the lawnmower
housing or deck 50. Such an option may be highly desirable and
unique in that the user may selectively operate the mower from
various user selectable inputs representing alternative power
inputs, a first power input being provided at the power selection
switch 21 representing a power input line from a battery pack 52,
with a second power input being provided at the power selection
switch 21 representing the AC line 22.
[0077] Further, as an alternative design element, an automatic mode
may be available for the power selection switch 21. Under the
automatic mode, the power control circuit 60 could include a solid
state relay which, as an example, has a zero crossing circuit for
voltage detection to activate a triac or other relay device to
automatically connect the electric motors to line voltage, when
plugged into the power control circuit. Such user selectable power
selection can thus be automated by an automated voltage or other
detection circuit or may be actuated by the switch 21 herein
described. It is appreciated that the automatic selection may be
overwritten by the user selection by setting the power selection
switch 21 to an alternative power source selection. In exemplary
embodiments, a switch/relay/solid-state switching device may be
utilized to accomplish power supply selection.
[0078] The controller may employ a set of algorithms to control the
battery assembly charge logic. For example, during an operation in
AC power mode, the algorithm employed by the controller may examine
the charge level of the battery assembly, and determine if
recharging of the battery assembly is necessary. In one embodiment,
a PIC algorithm(s) programmed on to an ASIC programmable controller
chip is utilized to control all of the charge logic. It is further
contemplated that the controller may contain a current sensor that
senses the electric current going to the motor 56 and
examines/references/compares the current level against the blade
speed to provide a soft start ramp up. The current sensor may also
serve as a current overload protection device, preventing circuit
breaker trip should a sudden drop of load occur (moving from a
taller grass area to a shorter or no grass area). Further, the
current sensor may signal a raise of the voltage to meet an
increased power demand, thus maintaining the blade speed at a
relatively consistent level.
[0079] Referring to FIGS. 12 to 15, there is shown an exploded view
of an exemplary embodiment of the mower 10. Enclosed between a
housing cover 82 and the deck 50 includes a controller (power
control module) 20 mounted on to a generally triangular shaped
support plate (control mount). Positioned on top of the controller
is the power selection switch knob 86, covered by a control box
cover 84. In one specific embodiment, the control mount is formed
as an A-frame structure that is independent of the housing cover
82. This configuration may aid in the assembly of the hybrid mower
10. The knob 86 is accessible by a user through an opening on the
housing cover 82. Also mounted on to the support plate are
additional circuit boards, electrical connectors, an AC receptacle
23, and cooling devices such as a heat sink and/or a fan. Attached
to the bottom of the support plate on one end is the top portion of
the motor 56, which is electrically connected to the controller 20,
and has its bottom portion attached to the deck 50. A shaft 57 is
attached to the motor to transfer rotational energy to the blade
51, which is rotatably attached to the bottom of the deck 50, and
connected to the shaft 57 through an opening at the bottom of the
deck 50. Positioned on the bottom of the deck 50 are a rear axle
302 supporting rear wheels, and a front axle 304 supporting front
wheels. The front and rear axles 302 and 304 may comprise
self-aligning, snap-in axles (as an assembly aid and labor
reducer).
[0080] As depicted in FIG. 15, the deck 50 is reinforced utilizing
reinforcing ribs 90 in combination with a steel reinforcing
framework, which may be provided by the lower handle 55b or
separate tube extending around the periphery of the mower deck and
intersecting with the handles and/or other structural components
mounted to the mower deck. In one specific embodiment, a steel tube
extending around the mower deck is connected to the mower deck
utilizing screws or other fasteners as required. In one embodiment,
the deck made of plastic with reinforcing framework is able to
achieve similar rigidity of a steel deck. It is understood that the
deck 50, the reinforcing ribs 90, and the lower handle 55b may be
made of various materials. For example, in a specific embodiment,
the deck and the reinforcing ribs are made of plastic.
Alternatively, the reinforcing ribs may be made of steel or other
metal materials. Additional suitable materials may include
fiberglass and other composite materials.
[0081] Also mounted on to the top of the deck 50 is the lower
handle 55b. In one specific embodiment, the lower handle 55b
includes a generally parallel portion, which is generally parallel
to the deck on one end, and an outwardly extended portion on the
opposite end. The outwardly extended portion forms an angle with
the deck 50. Thus, to securely support the outwardly extended
portion of the lower handle 55b, two handle support posts (axle
towers) 88 are positioned on either side of the deck 50 above the
location of the rear axle 302. This setup allows the outwardly
extended portion of the handle to establish a contact point with,
and be secured onto, the support post 88. A generally triangular
shape formed by the handle, the deck and the post allows the
attachment relationship between the lower handle 55b and the deck
50 to be more stable and less vulnerable to breakage and/or
flexing. In one specific embodiment, the axle towers 88, together
with the motor 56 and the controller 20 mounted on the deck 50,
form a box structure which is more stable and provides more
protection to the motor 56 and the controller 20.
[0082] It will be appreciated that strengthening the rigidity of
the mower deck may be desirable for providing an added feel of
quality for a consumer. It is understood that alternative designs
of the handle may be employed without departing from the scope and
spirit of the present invention. For example, in one embodiment,
the handle may have the lower handle adjustably attached to an
upper handle. Thus, the upper handle 55a may be folded down, as
illustrated in FIGS. 21 and 22, requiring a smaller storage and/or
packaging space. Height adjustment of the handle may also be made
available in this setup. Alternatively, the handle may be designed
as one-piece having one end attached to the deck 50 and the
opposite end to be handled/grasped by the user.
[0083] A single point height adjustment assembly is utilized in one
specific embodiment. As illustrated in FIGS. 16 and 17, this single
point height adjustment assembly includes a lever connected to a
first bar 302. The first bar 302 is connected to a second bar 304,
via a connecting rod. The connecting rod may be coupled to the
height adjustment handle 72 utilizing a spring 70. In exemplary
embodiments, the first bar 302 and the second bar 304 are offset
from a rotational axis for a set of wheels connected to the
lawnmower. In this manner, adjustment of the handle 80 will cause
the first and second bars 302 and 304 to move around fixed points
and thereby raise/lower the wheels as illustrated in FIG. 17. This
assembly may be applicable to electric, gas, and even push
mowers.
[0084] It is understood that alternative designs of the mower may
be employed without departing from the scope and spirit of the
present invention. For example, in one embodiment, the power
control switch 21 is positioned near the controller 20 on the deck
50 to reduce the amount of wiring needed for connection. In an
alternative embodiment, the power control switch 21 may be
positioned near the circuit breaker 28 on the upper handle 55a to
promote ease of use. Further, an AC cord holding device may be
utilized to promote easier retrieving or retracting of the AC cord
22. In one embodiment, as illustrated in FIG. 18, an AC cord
holding device 76 of a generally rectangular shape is rotatably
attached to the handle. Rotating the device 76 in one circular
direction (for example clockwise) may retract the AC cord 22, while
rotating the device 76 in a reverse circular direction (for example
counterclockwise) may allow user to retrieve more of the AC cord
22. Alternatively, the device 76 may be configured in other
geometrical shapes, for example, in a generally circular shape, as
depicted in FIG. 19. In still another alternative embodiment, the
cord holding device includes two stationary holders distanced apart
from each other (for instance 1 foot apart), where the user may
wind/unwind the AC cord around the two stationary holders to
retract/retrieve the cord 22.
[0085] Turning to an exemplary embodiment shown in FIG. 24 wherein
a power control circuit 60 is depicted providing, among other
things, the boost and conserve power features of the present
embodiment. The DC electric motor 56 is shown in electrical
connectivity with the various power control circuit elements 60,
100 which include the interlock handle switch 31, for example being
a double pole double throw switch, a circuit breaker 28 being, as
depicted herein, a 35 amp breaker, a boost/conserve switch 26, in
this example being a single pole double throw switch, a power
selection switch 21, in this example being a single pole double
throw switch, a battery pack 52 which is depicted as a 60 volt DC
battery pack providing 60 volts presented to the motor 56 when
operatively selected by the power selection switch 21, and a hybrid
AC/DC controller 100 which serves as a power inverter or step down
controller for converting the line voltage 120 VAC presented by the
plug 23. The battery pack is shown as sharing a common ground with
other portions of the power control circuit but may be in
electrical connectivity with the power control circuit in many
known and understood manners without actual connected electrical
wiring as long as the user operation of the lawn mower is actuated
through activation of the various switches.
[0086] In this present example, the boost selection switch 26
provides an increased voltage to the motor 56 by virtue of
modifying an input resistive value or timing signal value to the
pulse width modulation control unit 120 (see FIG. 25), which will
be described below, in order to alter the gating of the IGBT
thereby affecting the voltage wave form at the output of the power
inverter or step down controller 100. The in rush current limiter
may be provided as shown in order to prevent over-saturation of the
circuit during the initial startup and energizing of the circuit.
The rectifier 110 (see FIG. 25) as is commonly understood rectifies
the voltage from AC to DC, in this case utilizing a full bridge
rectifier as shown. However, many different forms of providing a
step down controller are known in the art and the depictions set
forth are not to be considered unduly limiting.
[0087] As depicted in FIG. 24, the design consists of the AC
receptacle 23 which connects to the hybrid AC/DC controller 100
acting as a voltage converter which in turn is connected to a
single pole double throw power selection switch 21 and a single
pole double throw boost switch 26. The boost switch 26 is the boost
conserve switch depicted and described herein and it provides
resistive loads to the CMOS micro-controller for pulse width
modulation control 120 when selected and opens the contacts when
off. The power selection switch 21 toggles the DC motor between the
output of the step down controller 100 and the DC battery voltage
source 52. The output of the power selection switch 21 feeds a
voltage meter shown which may be connected in parallel with the
double pole double throw interlock handle switch 31, the interlock
handle switch 31 toggling between shorting the DC motor 56 through
resister R1 to ground and connecting the output of the power
selection switch 21 through a circuit breaker 28 to the DC motor
56.
[0088] In this embodiment as depicted in FIG. 24, the boost switch
26 may provide increased voltage to the motor 56 when the hybrid
mower 10 of the present embodiment is plugged in and running off of
line voltage AC power. Such boost may be effectuated by modifying
the pulse width modulation control 120 through alteration of the
input resistive load at input pin 7 of the micro-controller shown
in FIG. 25. More description of the power inverter and/or step down
controller 100 of the power supply and mower of the present
invention will be set forth herein.
[0089] Turning to an additional embodiment for the power supply
circuit 160 of the present embodiment in FIG. 26, this embodiment
provides an AC wall plug 23 which connects to an AC voltage and to
the hybrid AC/DC controller 100 which in turn is connected to the
power selection switch 21 which allows toggling between output of
the AC/DC hybrid controller 100 when in the AC selection and to a
boost conserve switch 26 and alternative power source when in the
DC position. The boost conserve switch 26 toggles between shorting
the positive side of the battery source 52 directly to the boost
switch 26 when off and connecting the battery source 52 in series
with the secondary or boost battery 64 before connecting to the
power selection switch or AC/DC switch 21. The power selection
switch 21 then feeds a voltage meter V which is connected in
parallel with an interlock handle switch 31, here depicted as a
double pole double throw switch. The interlock handle switch 31
toggles between shorting the DC motor 56 through a resistor R1 to
ground and connecting the output of the power selection switch 21
through the circuit breaker 28 to the DC motor 56.
[0090] As depicted, in the example shown in FIG. 26, additional
voltage is provided to the DC motor 56 when the hybrid mower is
positioned in the DC power selection option and the boost switch 26
is activated thereby providing an additional 6 volts DC to the 60
volts DC provided by the battery 52. A secondary battery 64
provides additional voltage to the motor thereby increasing the
motor speed and corresponding blade speed through actuation of the
boost/conserve switch 26 to the boost setting. Thus, the power
control circuit or power supply 160 depicted in FIG. 26 allows the
operator, while in the DC battery operation mode, to increase the
operating speed of the motor 56 corresponding to/via the additional
voltage provided by the secondary battery 64. Controls are also
provided allowing the operator to select between the operation of
the motor 56 through the use of line voltage, namely 120 VAC, or
through the use of the battery pack 52. Depicted herein is a
secondary boost battery 64 which is provided separately from the
battery pack 52, but it may be more practical to provide a
secondary boost battery 64 in combination with and contiguous to
the battery pack 52 as assembled and shown in the figures. Thus,
the secondary boost battery 64 may be continuous with the battery
pack 52 or may be separate but is provided to add additional
voltage to the motor 56 in order to modify the operating output
voltage of the power supply as presented to the motor 56.
[0091] The hybrid AC/DC controller 100 as shown provides both power
inverter and step down capabilities in order to modify and regulate
the 120 VAC to the proper voltage required to run the DC motor 56.
However, these functions are provided to be only exemplary. The
controller 100 acts as an inverter via rectifier 110 and also acts
to properly modulate the voltage via the PWM controller 120 and
associated gates. The power inverter and step down controller 100
may be part of the power supply or power control module 60 (see
FIG. 24), 160 (see FIG. 26), 260 (see FIG. 27) and 360 (see FIG.
28) as needed, or may be excluded, depending on the voltage
characteristics of the input line voltage and the requirements of
the electric motor implemented in the present design.
[0092] An alternative construction for the power control is the
power supply circuit 260 depicted in FIG. 27 wherein both 120 VAC
may be provided to supply power to the motor 56 while optionally a
60 volt DC battery may be provided and may be operatively
selectable by the user through/via the power selection switch 21a.
As depicted in this example, the boost switch 26a is operative to
bring in series a secondary battery 64 which is 6 volts DC (when
set in "BOTH" mode) with the voltage provided by the hybrid
controller 100 of the power supply or the battery pack 52. The
secondary battery 54, as previously described and as depicted in
this embodiment of the power control circuit 260, may be in
combination with the battery pack or may be secondary and separate
therefrom. Additionally, as shown in the illustrated example, the 6
volt battery is brought into the circuit in series with the DC
output of the hybrid control 100 or with the battery pack 52. Also,
many variations for the structure, assembly and actual value of the
secondary battery 64 for all embodiments may be provided in order
to increase the voltage to the motor 56.
[0093] As depicted in FIG. 27, the power selection switch 21a
further provides for three settings allowing user selectable
options of powering the DC motor 56 by either 120 VAC, by the
direct battery pack connection or by a hybrid BOTH connection. When
operating in the strictly 120 VAC mode, the hybrid AC to DC control
100 of the present embodiment regulates and modulates the voltage
for proper supplying of voltage to the DC motor 56. Alternatively,
the power selection switch 21a provides for a DC operation whereby
the motor 56 is operated merely by the battery pack 52. A third
option is placement of the power selection switch 21a into the BOTH
mode, wherein there may be a limited amount of power contribution
from the battery. In such instance, voltage drops caused by
increased load on the motor 56 may result in increased contribution
from the battery pack 52. Additionally, as depicted in the
embodiment shown, the boost conserve switch 26a may be provided for
contribution of additional voltage from the secondary battery 64
when the power selection switch 21a is placed in either the BOTH or
DC mode. In such an instance, the secondary battery 64 is brought
in series with the voltage contribution from either the power
supply 100 or the battery pack 52.
[0094] Turning to FIG. 28, an alternative construction and
embodiment of the power control and supply circuit 360 is depicted.
In the example depicted, the power supply circuit 360 consist of a
120 VAC wall receptacle 23 which connects to the hybrid AC
controller 100 which in turn is connected to an exemplary single
pole double throw boost switch 26 thereby allowing the circuit to
bypass boost battery 64 when off or be connected to the boost
battery 64 when on. Additionally, the circuit continues to an
exemplary single pole double throw power selection switch 21 which
toggles between the output of the speed selection switch 26 when in
the AC position and the DC battery assembly 52 when in the DC
position. The power selection switch 21 feeds a voltage meter V
which is connected in parallel with an exemplary double pole double
throw interlock handle 31, the interlock handle switch 31 toggling
between short in the DC motor 56 through a resistor R1 to ground
and connecting the output of the power selection switch 26 through
a circuit breaker 66 to the DC motor 56. In this example of the
power control circuit 360, the boost or secondary battery 64 is
brought in parallel with the power pack 52 or with the output of
the hybrid controller 100 which may increase the current capacity
for the motor when in higher speed or boost mode.
[0095] Multiple variations of power control module or power supply
may be provided and are described herein. When mentioned herein as
a hybrid power controller, power supply, power control module, step
down controller or hybrid controller, these terms are collectively
meant to imply providing electricity to the motor placed on the
mower housing. No single element set forth in the exemplary
embodiments provided herein, namely the power supply elements of
the switches, battery packs, circuit breakers, inverters and
modulation elements are to be unnecessarily applied to the
interpretation of these terms. In fact, the power supply circuit
collectively described herein may be implemented through the use of
a significant number of alternative structures for regulation,
modulation, controlling or limiting the proper voltage or power to
the motor implemented in the examples herein. No unnecessary
limitation should be interpreted from the particular use of the
term controller, inverter, regulator or regulation or modulation as
depicted herein.
[0096] Turning to the exemplary power inverter and in combination
step down controller 100 which acts as a portion of the power
control module, the hybrid controller 100 receives as input 120
volts AC which, in this example, is inverted utilizing a full
bridge rectifier 110 depicted in FIG. 25. An in rush current
limiter is provided also to prevent current surges during initial
loading of the circuit and prevent further damage or
over-saturation. A number of different inverter designs may be used
in order to provide voltage rectification. As depicted in the
present example, a full bridge rectifier may be utilized but this
may be replaced with other known inverter circuitry as is available
and known in the art.
[0097] In addition, as depicted in FIG. 25, an optional boost
switch may be provided which may correspond to the boost switch 26
depicted in FIG. 24. In the present exemplary embodiment, the
optional boost switch may be operable to modify the input to the
pulse width modulation controller 120 which defines the voltage
output for the step down controller 100. As shown, a
micro-controller is utilized in order to set the appropriate pulse
rate for the PWM control and feeds into the insulated gate bi-polar
transistor (IGBT) which provides the switching or pulse gate driver
122 for the DC output of the hybrid AC/DC control 100. Thus, the
hybrid controller 100 incorporates, but does not necessarily
require, the utilization of voltage rectification and a voltage
rectifier as is necessary in combination with variations of voltage
modification such as a pulse width modifier. However, multiple
options for step down voltage and control are known and may be
utilized such as diode controls, triac controls, MOSFET controls
and the like. Many of these are well known in the art and may be
utilized in the step down controller and power inverter in
combination as described herein. Additionally, as depicted, the
pulse width modulation control circuit 120 receives as input in one
possible embodiment the ability to modify the voltage by use of the
boost switch. The boost switch in this embodiment modifies the
reference signal fed into pin 7 of the micro-controller for the
reference value which operates to modify the gating of the IGBT and
therefore, the voltage characteristics of the DC output depicted.
The boost mode depicted provides the alternative function of a
boost integrated with the power inverter and step down controller.
As shown integrated with the controller 100 in FIG. 24, the boost
switch can be alternatively provided in many connections and this
integrated boost switch may be integrated with many of the other
alternative embodiments.
[0098] Referring now to FIG. 40, the hybrid mower 10 may include a
switch for selectively activating a battery charge operation, such
as a charge mode active switch 124, or the like. The charge mode
active switch 124 may be utilized for switching the hybrid mower 10
from a battery charging mode to a mode where the battery is not
being charged, and then back again. In one specific embodiment, the
battery is charged in the mower while not in operation, either by
automatic switch or by user selectable switch. In another specific
embodiment, the battery may be charged while in use (e.g., while
mowing a lawn with the cord connected). In an embodiment with a
user selectable switch and in situ charging, an operator may be
able to control when power from AC mains is being utilized to
charge the battery. Further, a battery charge light 126 (e.g., a
Light Emitting Diode (LED) or another type of light and/or
indicator) may be provided to indicate when such charging is taking
place. It will be appreciated that the charge mode active switch
124 may be placed on the hybrid mower 10 and indicated accordingly
with various labels and/or indicia. Moreover, it will be
appreciated that a multi-colored LED and/or multiple LEDs may be
utilized to indicate various charging states to an operator, such
as the battery charging mode and modes in which the battery is not
being charged. Further, it will be appreciated that various battery
charging level indicators may be provided in a similar manner,
including various combinations of indicators (e.g., tones, flashing
lights, multi-colored lights, meters, and the like). Additionally,
it should be noted that battery charge information may be presented
by the battery itself (e.g., the battery may include an indicator
for demonstrating a charge level to a user of the hybrid mower
10).
[0099] As is known, many variations of a step down controller and
inverter may be utilized and in general, the power control module
of the present embodiment may utilize power input of 120 VAC and
may incorporate many switches and controls for electrically
connecting the DC motor to either the 60 volt DC battery or the DC
output of the hybrid power controller. This may include utilization
of a power source switch as indicated wherein the power source
switch effectively has a first power input as a connection of the
power control module of the DC output of the power inverter and
step down controller 100 or receive as a second input the 60 volt
DC of the battery pack, the power selection switch providing the
ability of the operator to switch between 120 VAC power and 60 VDC
power from the battery pack. The power selection switch may be
directly connected to the DC motor, in this exemplary embodiment a
60 volt DC motor, which operates the blade. The 60 volt DC motor
may be operationally modified by utilization of a boost switch
which is optional in many embodiments depicted herein, the boost
switch changing voltage applied to the DC motor from 60 volts by an
incremental value, thereby increasing rotational speed of the blade
as necessary by the operator. Such increase in blade speed, as
previously indicated, may be necessitated by thicker grass or other
items being cut/mulched by the hybrid mower 10 of the present
embodiment. This boost/conserve function which is shown herein
provides the ability through the many embodiments disclosed to
increase the voltage of the power control module, thereby
increasing the rotational speed of the blades. As indicated, this
may be desirable for short periods of time and may provide a first
power output of the power control module, the first power output
higher than a second power output, the second power output being a
conserve feature wherein the DC motor draws less current and
thereby increases the battery life charge of the battery pack.
However, such feature does not have to be implemented only with the
use of DC operation and DC power input as it is apparent that the
increase rotational speed (boost) feature may be implemented also
with 120 VAC wall power by increasing the DC voltage output of the
hybrid AC/DC control 100 or by adding a supplemental DC power
supply from the operating batteries, whether primary or
secondary.
[0100] Referring now to FIGS. 29 through 31, an alternative
embodiment of the electric lawnmower of the present invention is
depicted. In such an alternative construction, the electric
lawnmower 500 has a first and a second blade 551A and 551B mounted
to a housing 550. Driving each of the blades, 551A and 551B are a
first and second motor 552A and 552B as depicted in FIGS. 30 and
31. The alternative dual motor construction as is depicted may
substantially use similar power control circuitry with the
modification in the series or parallel connection of the DC motors
552A and 552B to the power supply voltage. It may be desirable to
provide the DC motors with either 120 VAC line power (which is
current rectified) or with the battery pack supplied DC electrical
power. In the multiple embodiments provided, two blades may be
provided to cut vegetation within and below the deck 550 of the
electric lawnmower 500. A total cutting width of approximately 19
inches may be provided wherein each of the blades may be about 9.5
inches (end-to-end length). When attempting to cut a relatively
large diameter with a single blade, such as the entire 19 inches of
the housing width, excessive battery drain and power consumption
may be experienced due to air movement resistance encountered by
the blade. The air movement load may goes up exponentially as
related to the blade speed thus adding a significantly higher load
in addition to the normal vegetation cutting resistance load. The
increased rotation speed of the blade and increased length of the
blade may cause a significant proportion of the power supply to be
used for moving air as opposed to cutting of vegetation.
[0101] Thus, for cutting of wider diameters, it may be preferable
to utilize two motors and two blades working in tandem. By
utilizing two motors as opposed to a single motor with an increased
rotational speed, significant power savings may be experienced and
run time lengths for the power supply battery as well as power
consumption in both DC and AC operations may be significantly
reduced. Additionally, when using dual motors 552A and 552B, such
dual motor implementation may preferably not be used in series in
conjunction with battery operation due to the motors running at
half speed, i.e. sharing the battery pack supplied voltage in
series. Thus, in a preferred implementation for dual motor use,
although not necessarily required, the DC electric motors may
preferably be placed in parallel (as is depicted in FIG. 30) in
certain operations, such as when operated by the battery pack, and
possibly in series in others, such as when connected to higher line
voltage. However, the DC motors may be placed in either operation
as is deemed necessary. Also, power usage may not become an issue
when providing line voltage through the hybrid AC to DC controller
wherein the AC current is rectified for operation of the DC motors
depicted.
[0102] As depicted in FIG. 30, the dual DC motors 552A and 552B for
the power control and supply system 520 of the present embodiment
are shown in parallel. A circuit breaker may be provided in
combination with the interlock handle switch as previously
described in order to operationally connect and disconnect the
motors as selected by the user through the blade clutch handle 31.
Further, an AC/DC operational switch may be provided for selection
of either power supply, either AC line voltage or DC battery power
supply as previously described. Further, a hybrid AC/DC controller
may be utilized to implement rectification of the 120 VAC to
provide an adequate supply of DC current to the motors 552A and
552B. Further, the boost switch may be provided in combination with
the hybrid controller or separately as previously described as
various combinations of these individual elements may be
selected.
[0103] In an embodiment, the dual blade DC motor combination may
provide a 21 inch path for cutting vegetation wherein similar
rotational speeds of 16,000 to 19,000 feet per minute blade speed
may be experienced either on battery or on the AC line voltage with
the higher rotational speed indicated when operating using line
voltage. Such rotational speed indicates a potential of 5,800 to
6,900 RPM. These speeds typify the efficiency of the motor when the
mower 10 is implemented in a non-cutting environment. During
cutting of vegetation, the rotational speed of the blade tip may be
12,000 to 18,000 feet per minute, again with the higher rotational
speeds indicated when operating on line voltage. These speeds
relate to approximately 4,300 to 6,500 RPM on each of the two
blades providing a 19 inch cutting diameter. Similar motors may be
provided as previously described for implementation by the electric
lawnmower of the present invention.
[0104] Further, the horsepower at cutting speed may be anywhere
from 1.5 to 2.0 HP with the battery capacity being approximately
480 watt hours as necessary. Excellent cutting at these speeds with
either the single motor or dual motor implementation may be
experienced with adequate blade speed, cutting action and suction
experienced within the lawnmower deck or housing. Mulching may also
be accomplished when operating at these speeds and may be increased
by implementation of the boost feature previously described which
would be available to both DC electric motors during operation if
implemented in one of the many various boost and conserver
implementations previously described. Referencing again FIG. 30,
both motors are depicted in parallel combination with the motors
seeing approximately 60 volts from the power supply. When the
motors are in such parallel connectivity, as one motor is loaded
disproportionately due to various factors from either air
resistance or vegetation and cutting resistance, the second motor
slows down due to the reduced power available from the battery
caused by the internal resistance and the higher amperage of the
power supply as is depicted. Such self adjustment of the motor and
hence blade speeds provide automated self regulation of both
motors.
[0105] Given the power supply and control embodiment depicted in
FIG. 31, the user may select either AC or DC operation, which also
serves as a circuit setting switch, and places the two motors 552a
and 552b in either series or parallel configuration. When in DC
mode, the battery 52 supplies constant current and may result in
better performance of the motors. Further, when placed in DC mode,
the motors are in parallel and, as one motor is loaded
disproportionately, the second motor may slow down due to the
reduced power available from the battery pack caused by the
internal resistance of the power supply design and motor
configuration and by the higher amperage.
[0106] Turning to the alternative construction and embodiment of
the power supply and control circuitry of FIG. 31, the power supply
and control circuit 560 indicates that the dual DC motors 552A and
552B are connected to the output of the AC/DC power selection
switch 521 which toggles the power supply of the circuit from the
full bridge rectifier 501 when in the AC position, to the DC
battery source 52 when in the DC position as is depicted. The
output of the power selection switch 521 feeds the voltage meter
shown which is connected in parallel with the double pole, double
throw interlock handle switch 31. The interlock handle switch 31
toggles between short in the DC motors 552A and 552B through a
resistor, R1 to ground and connecting the output of the power
selection switch 521, a three pole double throw switch in this
disclosed embodiment, through circuit breaker 28 to the dual DC
motors 552A and 552B. When the power selection switch 521 is in the
AC selection position, the dual motors M1 and M2 are connected in
series thereby splitting the voltage output of the rectifier. In
such operation, the full bridge rectifier may provide 120 VDC with
60 V the seen by each motor. When the AC/DC power selection switch
521 is in the DC position, the motors M1 and M2 are connected in
parallel thereby each sharing in the DC voltage output of the
battery pack. The battery, being a constant current power supply,
may provide better performance of the DC motors M1 and M2 in
parallel and thus the connection as is described may be provided
with the capability of switching between parallel and series
connectivity of the motors M1 and M2 depending on the power
source.
[0107] Further, as disclosed in FIG. 31, a full bridge rectifier or
possibly other current rectification is depicted wherein the 120
VAC is input into the hybrid controller (not depicted as previously
shown for simplicity). The full bridge rectifier in this embodiment
may readily be replaced by various rectification circuitry, such as
that previously disclosed herein. Thus, the rectifier depicted may
be replaced by other current rectification means to rectify the
current from AC to DC. These known systems include but are not
limited to pulse width modulation which may readily be implemented
herein.
[0108] When AC mode is selected from the user selectable power
selection switch shown in FIG. 31, the total current going through
many of the switches and electronic circuit elements presented
herein may be one half of that going through the same switches and
electronic circuit elements in the parallel or battery mode, given
the embodiments depicted as a result of the rectification of the
current and positioning of the loads. In other words, as shown in
FIG. 31, the battery pack provides 60 VDC which is shared by the
dual motors in parallel and the AC input line provides 120 VDC to
be split by the dual motors in series in the disclosed embodiments.
The response to uneven loading also may be more desirable as
previously described in parallel as opposed to in series mode,
since, when in series mode, as one motor is disproportionately
loaded and slows down, the other motor will speed up. The actual
speed modification of the motors in series however may be mitigated
due to the nature of the air resistance to the blades and the
significant amount of energy and load required to move the air in
the mower housing. The relationship between air movement resistance
and blade speed is an exponential relationship thus adding a
significantly higher load when the blade is spinning faster, thus
tending to cause the blades to operate at similar speeds in these
embodiments. However, either combination of either series or
parallel connection of the two DC motors as is depicted may readily
be implemented and such description as set forth herein is not
deemed limiting.
[0109] In both configurations of the dual motor design depicted,
the ability and functionality of the boost and conserve features
are still present in that the blade speed for both motors may be
reduced in a conserve mode, particularly when operating off of the
DC battery power supply in order to increase charge life. As shown
in FIG. 30, a boost and conserve switch and feature may be
implemented in conjunction with the hybrid controller shown.
However, many differing combinations of the boost and conserve
feature previously described may be applicable to either design and
power supply shown. In conjunction with the power supply and
control depicted in either embodiment, a secondary battery pack may
be utilized as discussed herein to increase the voltage output of
the DC operation and power supply thereby increasing the blade
speed for both motors while also allowing battery use to be
conserved in a second state thereby increasing overall run life per
charge. Alternatively, increased voltage may be provided directly
from the hybrid controller as depicted when drawing power from AC
power supply.
[0110] In addition to the dual motor or other designs depicted, a
dual voltage motor may also be desirable. Such dual voltage may be
seen by the electric motor when switching between rectified line
voltage from an outlet or from a battery pack, which may, in one
embodiment, roughly be one half the line voltage. It would be
preferable that a dual voltage electric motor be implemented for
hybrid operation wherein all electrical or electro-mechanical
aspects of the electric motor are in operation and use when
utilizing either high voltage operation or lower voltage operation.
By all electrical or electro-mechanical aspects being in use, it is
meant that windings, brushes, commutators and other aspects of the
electrical motor are mostly in operation and electrically connected
to the power supply, whether high voltage AC or lower voltage DC.
The described DC voltage permanent magnet motor design of the
exemplary embodiment allows a single motor to operate using two
different DC voltages. This may be accomplished through providing a
hybrid controller which places electrically separated windings on
the armature in either serial or parallel configuration, parallel
for lower voltage operation and serial configuration for higher
voltage configuration. In either configuration, the voltage
potential across each coil will be about 60 VDC, or half the high
voltage, as the coils are placed in series when in AC mode and in
parallel when in lower voltage mode. Similarly alternative
constructions may be implemented in the embodiment shown.
[0111] Presently, in the various embodiments depicted, a dedicated
electric motor design may be implemented in the hybrid electric
lawnmower which implements the ability and functionality of direct
AC power supplied from a standard line voltage power source
providing 120 VAC, or, of power provided from a secondary power
supply source such as a battery pack, which would supply about 60
VDC to about 72 VDC, as is necessary or as is designed, all to the
same electric motor driving the blade on the mower housing. In one
embodiment, the hybrid controller utilized in the embodiment may
convert the 120 VAC to 120 VDC through the use of various
techniques, such as a rectifier or other circuit implementations.
In such implementation, the user would elect to switch the mower
power supply selection switch to AC, the hybrid controller would
rectify the voltage to DC and the motor would operate at a possibly
higher voltage supply. Alternatively, user selection of the power
selection switch to DC would electrically connect the battery pack
or other lower voltage power supply to the motor in order to
operate the blade on the mower housing.
[0112] In either situation, user selection of AC operation as when
the mower embodiment depicted is plugged into an outlet, or when
user selection has been modified to DC operation for running the
mower off of the battery pack or other direct current power supply,
the electric mower of the present embodiment may alternate between
high voltage operation or low voltage operation, the low voltage
supply typically being one half the high voltage supply. Through
implementation of dual core windings which are electrically
separated and both rated at the lower voltage level, the rpm of the
hybrid motor presently described may be maintained in either
voltage configurations.
[0113] Referring now to FIG. 32, there is shown a dual voltage
motor 800. In this exemplary embodiment, the dual voltage motor 800
includes a permanent magnet 816 and a single armature 808 connected
to an axle 818. Attached to the armature 808 are a first commutator
802 separated from a second commutator 804. The first commutator
802 connects to a first set of windings (coils) 810, and the second
commutator 804 connects to a second set of windings 812. The first
set of windings 810 is separated from the second set of windings
812. Further, the first commutator 802 is in electric contact with
a corresponding first set of brushes 806A and 806B, and the second
commutator 804 is in electric contact with a corresponding second
set of brushes 814A and 814B. The two sets of brushes (806 and 814)
may be selectively configured through the use of a user selection
switch which reconfigures the windings (810 and 812) on the motor
from series connectivity (for higher voltage source such as
rectified line voltage), to parallel connectivity (for a lower
voltage source such as a battery pack). If the higher voltage is
approximately twice the potential of the lower voltage, the power
supply will provide approximately the same voltage potential across
a first and a second commutator on the electric motor.
[0114] Referring now to FIG. 33, there is shown a parallel
configuration of the dual voltage motor. In such configuration, the
positive terminal of the V1 voltage source is connected to the
terminal T1 of the motor, and the negative terminal of the V1
voltage source is connected to the terminal T2 of the motor.
Terminals T1 and T2 are connected to the first commutator 802
through brushes 806A and 806B, which creates a voltage potential of
V1 across the first coil 810. The positive terminal of the V1
voltage source is also connected to terminal T3 of the motor, and
the negative terminal of the V1 voltage source is also connected to
terminal T4 of the motor. The terminals T3 and T4 are connected to
the second commutator 804 through brushes 814A and 814B, which
creates a voltage potential of V1 across the second coil 810.
[0115] Referring to FIG. 34, there is shown a series configuration
of the dual voltage motor. In such configuration, the positive
terminal of the V2 voltage source is connected to the terminal T1
of the motor, and the negative terminal of the V2 voltage source is
connected to the terminal T4 of the motor. Further, terminal T2 is
connected in series to terminal T3. Terminals T1 and T2 are
connected to the first commutator 802 through brushes 806A and
806B, and terminals T3 and T4 are connected to the second
commutator 804 through the brushes 814A and 814B. This
configuration creates a voltage potential of V2 across both coils
which means that each coil will have a potential of a half of V2 in
the present embodiment.
[0116] FIG. 35 depicts an exemplary circuit implementation of an
electric mower utilizing a dual voltage motor 553. The coils may be
placed in either a high voltage configuration or a low voltage
configuration by the user. In a high voltage configuration the
coils 554A and 554B are placed in series. In a low voltage
configuration the coils are placed in parallel. User selection of
the high or low voltage configuration may be achieved through the
use of the three pole double throw switch SW1 which provides the
operator of the hybrid mower presently described in this embodiment
the ability to provide a power supply of 120 VAC for higher voltage
operation or 60-72 VDC for lower voltage operation.
[0117] In one specific embodiment, for example, when the mower is
connected to a standard AC power source of 120 VAC, a rectifier may
rectify the voltage to about 120 VDC (a higher voltage source).
Thus, a series configuration will provide each set of coils about
60 VDC. Alternatively, when the mower is connected to a 60 VDC
battery pack (a lower voltage source), a parallel configuration
will provide each set of coils about 60 VDC as well. Substantially
the same voltage provided to the sets of coils in both higher and
lower voltages results in substantially the same revolutions per
minute/rounds-per-minute (RPM) of the motor. In this manner, the
dual-voltage lawnmower may be capable of executing speed control
over the motor and the cutting blade without utilizing an
electronic controller. This may represent a significant cost
benefit to a consumer. In one specific embodiment, the lack of a
controller may represent a cost savings of approximately ten
percent. It will be appreciated that the number of windings in the
motor may vary and/or the diameter of wires including the windings
may vary.
[0118] It will be appreciated that while the hybrid device
disclosed herein has been described with some specificity as a
hybrid lawnmower, many other devices may be provided which also
utilize some or all of the features disclosed herein. Moreover,
while the hybrid lawnmower described above has been shown and
described as including a cutting component housing including a
cutting blade, it will be appreciated that the cutting blade is
exemplary only, and a variety of other working elements may be
utilized with the hybrid electric device of the present invention.
For example, FIG. 41 illustrates a hybrid snow blower 10. The
hybrid snow blower may include a cutting component housing
including at least one impeller/fan (blowing component). In
exemplary embodiments, the hybrid snow blower 10 may implement a
removable battery/battery assembly which may be removed after each
use of the snow blower 10 and stored indoors for preserving the
battery during winter conditions. It is contemplated that other
hybrid powered devices may be provided as well, including large
devices similar to the mower and the snow blower (e.g.,
chipper/shredders, reel mowers, tillers, thatchers, and/or
aerators), as well as small devices, such as handheld devices like
trimmers and/or edgers. Moreover, it will be appreciated that these
devices may include a variety of working elements. Further, these
working elements may be provided in various quantities. For
example, one hybrid electric device may include two working
elements (and various types and combinations of motors for driving
the working elements as needed), while another hybrid device may
include three working elements (with an appropriate number and
configuration of motors as needed).
[0119] It is believed that the present invention and many of its
attendant advantages will be understood by the foregoing
description, and it will be apparent that various changes may be
made in the form, construction and arrangement of the components
thereof without departing from the scope and spirit of the
invention or without sacrificing all of its material advantages.
The form herein before described being merely an explanatory
embodiment thereof, it is the intention of the following claims to
encompass and include such changes.
* * * * *