Note: Descriptions are shown in the official language in which they were submitted.
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UNIVERSAL, RETROFITTABLE POWERHEAD
FOR SMALL GASOLINE ENGINE POWER IMPLEMENTS
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to electric motors for driving land
vehicles such as lawn mowers, snow throwers, tillers,npumps and
other tools, and more particularly to a universal powerhead
employing an electric motor and a universal mounting plate for
enabling the electric motor to be secured in place of an internal
combustion engine of the land vehicle or tool without requiring
modification to a frame portion thereof.
2. Discussion
Land vehicles such as lawn mowers, snow throwers, tillers,
thatchers and other vegetation, gardening and agricultural-like
products used in home or commercial environments, as well as many
other forms of tools such as string trimmers, chain saws, leaf
blowers, pumps, etc., have traditionally been used with internal
combustion engines. The internal combustion engine provides
power for either propelling the land vehicle over a ground
surface or for driving one or more sub-components of the land
vehicle or tool necessary for enabling the device to perform its
intended purpose. Such internal combustion engines typically are
relatively small displacement engines having a horsepower rating
less than 10 and more typically less than 5. The footprint of
an internal combustion engine manufactured by a certain
manufacturer typically does not vary, or varies insignificantly,
regardless of the form of land vehicle or tool with which the
engine is used. This is provided that the displacement
(horsepower rating) is the same for the particular engine under
consideration. Put differently, the footprint of an internal
combustion engine produced by a certain manufacturer and having
a given horsepower rating will not vary depending upon the form
of land vehicle or tool with which it is used. Thus, for
example, every 3.5 horsepower internal combustion engine
manufactured by a given manufacturer typically will have the same
footprint regardless of the device with which it is used.
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In most instances, the gasoline powered engine of a land
vehicle will be vertically mounted such that the crankshaft of
the engine is vertically positioned. The only exception is where
the engine must be horizontally mounted. Such applications
typically include those in connection with snow throwers,
tillers, and like equipment which incorporate an element which
is driven about a generally horizontally disposed axis of '
rotatioi~r. With these forms of land vehicles the engine is
typically mounted such that its crankshaft extends generally
horizontally rather than vertically. The overall footprint and
outer dimensions of the engine, however, do not vary: only the
manner in which the engine is mounted to the land vehicle ~(i.e.,
either vertically or horizontally). Thus, a manufacturer of
various land vehicles may be able to use one internal combustion
engine of a specific engine manufacturer on a wide variety of
land vehicles or tools which it manufacturers and sells for
various applications.
With the increasing attention to the environment, internal
combustion engines have come under increasing scrutiny.
Relatively small horsepower internal combustion engines typically
used with land vehicles such as lawn mowers, snow throwers,
tillers, thatchers, etc., produce a relatively high degree of
emissions compared to, for example, present-day automobiles which
include extensive pollution control equipment designed to reduce
hydrocarbon emissions. In many instances, a relatively small
internal combustion engine used with a land vehicle, for example
a 3.5 horsepower engine, can produce a significantly higher
degree of unwanted hydrocarbon emissions than the internal
combustion engines used with present-day automobiles. With
government regulation of air quality standards, and particularly
of air pollution produced by motor driven or powered vehicles,
it is anticipated that land vehicles having relatively small
displacement internal combustion engines will come under ,
increasing scrutiny in the years to come for the pollutants that
such engines produce.
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In view of the above, it would be highly desirable to be
able to mount an electric power source, such as an electric
motor, directly to a frame portion of a land vehicle or tool
either during assembly of the land vehicle at a factory or
thereafter by authorized personnel of the manufacturer of the
land vehicle or tool, or other individuals. As will be
appreciated, electric motors do not provide any airborne
pollutants which negatively impact the atmosphere. With
relatively recent advances in battery technology, batteries are
now available which can power electric motors suitable to drive
land vehicles such as lawn mowers, snow throwers, tillers, etc.,
for a continuous length of time in the range of about '20-45
minutes without adding significant weight or cost to the device
over that of a conventional internal combustion engine. For many
applications such as the mowing of residential lawns and clearing
of snow on residential driveways, this running time is more than
sufficient to enable the operator to cut a residential lawn or
clear a residential driveway of snow on a battery single charge.
Thus, electric motors are becoming increasingly popular for land
vehicles and a wide variety of other tools used for various
purposes where an extended running time of an hour or more is
typically not need to accomplish the desired task.
While electric motors have therefore become common in many
instances, many manufacturers of various forms of land vehicles
still are relying primarily on the internal combustion engine as
the exclusive means for powering one or more types of land
vehicles or tools which they offer for sale. This is likely due,
at least in part, to the belief of many manufacturers that it
would be necessary to design an electric motor requiring a
specific mounting assembly for each model of land vehicle offered
by the manufacturer.
Thus, there is a need for an electric motor assembly
having some form of universal mounting assembly which would allow
the electric motor to be quickly and easily mounted to a frame
of a land vehicle which was originally designed for an internal
combustion engine, and to replace the internal combustion engine
as the power source for the land vehicle. There is further a
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need for such an electric motor and mounting assembly which could
be secured to a wide variety of land vehicles or tools in place
of a specific make of internal combustion engine without
requiring the manufacturer to modify a frame portion of a land
vehicle beforehand.
Accordingly, it is a principal object of the present
invention to provide an electric powerhead apparatus having an '
electric motor and a universal mounting plate. The universal
mounting plate would allow the powerhead apparatus to be quickly
and easily fitted to a wide variety of land vehicles or tools in
place of a specific model of internal combustion engine
originally used or intended for use with the land vehicle or
tool, and without requiring a frame portion of the land vehicle
or tool to be significantly modified to accept the powerhead
apparatus in place of the internal combustion engine.
It is another object of the present invention to provide
a powerhead apparatus having a universal mounting plate as well
as a secondary mounting assembly for allowing the apparatus to
be mounted in either a vertical orientation or a horizontal
orientation with no modification to the apparatus and with little
or no modification to the land vehicle or tool to which the
powerhead apparatus is to be mounted in lieu of the~original
planned-for-use internal combustion engine.
It is still another object of the present invention to
provide a universal powerhead apparatus which is standard for use
with a wide variety of land vehicles and tools and which includes
an overall footprint which is substantially similar to the
internal combustion engine which it is designed to replace, such
that the powerhead apparatus does not interfere with other
component parts of the land vehicle or tool designed to be
positioned in the near vicinity of the power source of the
vehicle or tool.
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It is still another object of the present invention to
provide a universal powerhead apparatus having a mounting plate
and a secondary mounting assembly, where the mounting plate is
adapted to secure an electric motor of the apparatus such that
the output shaft of the motor is orientated in a vertical
position, and the secondary mounting assembly is adapted to
~ secure the apparatus such that the output shaft is orientated in
a horizontal position.
It is still another object of the present invention to
provide a universal powerhead apparatus having a universal
mounting plate and a secondary mounting assembly, where each of
the universal mounting plate and secondary mounting assembly do
not require adapters or other additional component parts to allow
the powerhead apparatus to be secured to a variety of land
vehicles or tools originally designed to be used with a specific
internal combustion engine.
It is a further object of the present invention to provide
a universal powerhead apparatus adapted to be used with a wide
variety of land vehicles or tools in place of an internal
combustion engine, where the apparatus includes an electric motor
and a battery for powering the electric motor, as well as a
battery charger interface assembly for allowing the battery of
the apparatus to be quickly and easily recharged. It is still
a further object to provide the powerhead apparatus with an
interlock assembly which prevents the electric motor of the
apparatus from being turned on while an external battery charger
is secured to the charger interface circuitry and for preventing
an external charger from being hooked-up to the charger interface
circuitry while the electric motor of the apparatus is running.
3 0 SUN~IARY OF THE INVENTION
The above and other objects are accomplished by a
universal powerhead apparatus in accordance with the preferred
embodiments of the present invention. The universal powerhead
apparatus generally comprises a housing having an overall
"35 footprint substantially similar to a specific make of internal
combustion engine, an electric motor disposed within the housing
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and a universal mounting plate secured to a portion of the motor.
The universal mounting plate is adapted to be secured to a frame
portion of a wide variety of land vehicles or tools without
modification to the frame portion. This enables the powerhead
apparatus to be substituted for an internal combustion engine of
the land vehicle or tool while assembling the device at a factory
or other like facility, or even retrofitted to the device to
replace an internal combustion engine thereof with little or no
modification to the placement of other components of the device.
It is still another object of the present invention to
provide a universal powerhead apparatus adapted to be secured to
a wide variety of land vehicles or tools, and which is adapted
to be powered by an AC power source, and which further includes
an interlock assembly which disables an electric motor of the
apparatus when a portion of the interlock assembly is removed
from the apparatus.
In one preferred embodiment the powerhead apparatus may be
secured to a frame portion of a land vehicle or tool such that
the electric motor of the apparatus is orientated vertically.
In an alternative preferred embodiment of the apparatus, a
secondary mounting assembly is included which allows the electric
motor to be mounted to a frame portion of the land vehicle or
tool such that the output shaft of the electric motor extends
generally horizontally. In the first-described preferred
embodiment, the vertical orientation of the output shaft of the
motor allows the powerhead apparatus to be used with land
vehicles such as lawn mowers which require a vertically
orientated output shaft for driving a cutting blade. In the
just-described alternative embodiment, the horizontal mounting
of the apparatus allows the apparatus to be used with land
vehicles having an implement required to be rotated about a
horizontal axis. Such land vehicles may include snow throwers,
tillers and thatchers.
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In the preferred embodiments the universal powerhead
apparatus has an overall footprint which is substantially similar
to the specific make of internal combustion engine which it is
designed to replace. This allows the universal powerhead
~ 5 apparatus to be secured to the land vehicle or tool without
requiring other component parts of the device normally positioned
about the perimeter of the internal combustion engine to be moved
and mounted elsewhere on the frame portion, which could
complicate the assembly of the device or the retrofitting of the
powerhead apparatus to the device in lieu of an internal
combustion engine. In one preferred embodiment both the
universal mounting plate and secondary mounting assembly are
secured to the apparatus in a manner which does not present an
interference problem no matter which mounting component is used
to secure the powerhead apparatus to the frame of the land
vehicle or tool. In this manner both the universal mounting
plate and secondary mounting assembly may be provided with the
apparatus without the drawback of the unused one of the two
interfering with other components of the land vehicle or tool
which are positioned adjacent the apparatus.
The universal powerhead apparatus of the present invention
thus allows an electric motor to be secured to a frame portion
of a wide variety of land vehicles or tools which were originally
designed to be used with a specific make of internal combustion
engine without requiring modification to the frame portion of the
land vehicle or tool, or repositioning of other components
designed to be mounted in close proximity to the internal
combustion engine. The universal powerhead apparatus is further
readily retrofittable to a wide variety of land vehicles or tools
which require either a vertically orientated output drive shaft
or a horizontally orientated output drive shaft without
significant modification to the apparatus or to the frame portion
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of the land vehicle or tool. Accordingly, the apparatus of the
present invention obviates the need for a manufacturer of various
types of land vehicles or tools to manufacture and stock a wide
variety of electric motor and mounting assemblies for use with
each specific type of land vehicle or tool to be manufactured.
The substitution of the universal powerhead apparatus of
the present apparatus further provides the land vehicle or tool '
with a power means which provides no airborne pollutants or other
environmental drawbacks normally associated with internal
combustion engines. This, in turn, allows the device to be used
in enclosed environments such as factories where the emissions
normally produced by an internal combustion engine might give
rise to a health concern.
BRIEF DESCRIPTION OF THE DRAWINGS
The various advantages of the present invention will
become apparent to one skilled in the art by reading the
following specification and subjoined claims and by referencing
the following drawings in which:
Figure 1 is a perspective view of a land vehicle in the
form of a lawn mower including a universal powerhead apparatus
in accordance with a preferred embodiment of the present
invention mounted thereon:
Figure 2 is an enlarged perspective view of the powerhead
apparatus shown in Figure 1~
Figure 3 is a plan view of the apparatus shown in Figure
2:
Figure 4 is a side view of the apparatus shown in Figure
2;
Figure 5 is a bottom view of the apparatus shown in Figure
2;
Figure 6 is a rear view of the apparatus of Figure 2
showing the charger interface assembly electrically coupled with
an external battery charger and the interlock assembly key
removed:
Figure 7 is a perspective view of the universal mounting
plate secured to a motor of the apparatus;
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Figure 8 is a rear view of an alternative preferred
embodiment of the present invention adapted to be used with an
AC power source showing the apparatus coupled via an AC power
cord to an AC receptacle;
' S Figure 9 is a perspective view of a snow thrower
incorporating the powerhead apparatus of the present invention;
w Figure 10 is a perspective view of a tiller incorporating
the powerhead apparatus of the present invention:
Figure 11 is an exploded perspective view of the electric
motor of the powerhead apparatus uncoupled from the universal
mounting plate; and
Figure 12 is a cross-sectional view of the universal
mounting plate taken in accordance with section line 12-12 in
Figure 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Figure 1, there is shown a vegetation cutter
in the form of a lawn mower 10 incorporating the universal
powerhead apparatus 12 in accordance with a preferred embodiment
of the present invention. It will be appreciated immediately
that while the powerhead apparatus 12 will be described in
connection with a lawn mower, that the apparatus is equally well
adapted for use with a wide variety of tools requiring a power
source for driving a component thereof. Virtually any land
vehicle or tool which has been designed for use with a small
internal combustion engine is within the intended scope of use
of the powerhead apparatus 12.
With further reference to Figure 1, the powerhead
apparatus 12 is adapted to be quickly and easily secured to a
frame portion, in this case a deck of the lawn mower 10, to
replace a specific make and displacement internal combustion
engine originally intended to be mounted on the lawn mower 10.
The powerhead apparatus 12'is quickly and easily secured to the
f.
deck 14 via a universal mounting member of plate 16 which secures
a main body portion 18 rigidly and fixedly to the deck 14. The
universal mounting plate 16 and main body portion 18 each have
a "footprint" which is substantially similar to the specific
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model of internal combustion engine which the apparatus is
designed to replace. The powerhead apparatus 12 can thus be
assembled to the deck 14 by a manufacturer at a factory or other
like facility or even retrofitted to the lawn mower 10 by a
dealer or other factory authorized service representative or
other individual. Since the overall footprint of the powerhead
apparatus 12 is substantially similar to that of the specific
engine which it is designed to replace, the universal mounting
plate 16 may be secured directly to the deck 14 without any
modification of the deck 14 such as the drilling of additional
holes therein, the use of external adapter plates, etc. The
substantially identical footprint further enables the po~aerhead
apparatus 12 to be secured to the deck 14 without requiring other
component parts originally supplied with the lawn mower 10 to be
relocated on the lawn mower. The substantially identical
footprint further allows the retrofitting or original mounting
of the powerhead apparatus 12 to the lawn mower 10 to be
accomplished quickly, easily and without significant disassembly
of the lawn mower l0 except for the originally supplied motor
when the apparatus is retrofitted to the lawn mower.
Since the powerhead apparatus 12 includes an electric
power source, there are none of the emissions produced by the
apparatus that would otherwise accompany an internal combustion
engine. Also, since the electric power source of the powerhead
apparatus 12 does not require any lubricating oil, fuel filter
element or air filter, the overall maintenance of the lawn mower
10 is reduced significantly and the problem of disposing of used
oil and other components which might present a hazard to the
environment if not disposed of properly is completely eliminated.
The internal electric motor of the powerhead apparatus 12 is
further significantly more quiet than any internal combustion
engine.
With specific reference to Figure 2, the main body portion
18 of the powerhead apparatus 12 includes a housing 20 having a
top member 22 secured via a hinge 23 and a conventional latch 23a
to a base portion 24. Within the housing 20 is a vertically
orientated electric motor 26 which is secured to the universal
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mounting plate 16 such that it is rigidl~~ and fixedly supported
mostly within the ~:ousing 18. A plurlity of rechargeable
batteries are also anted within the hous_ng 18 for powering the
electric motor 26. The motor 26 is commercially available and
- 5 presently manufactured by the assignee of the present invention
and used commercially on a variety of products of the assignee.
The preferred embodiment of the powerhead apparatus 12
shown in Figure 2 further includes a secondary mounting assembly
28 comprised of a first U-shaped bracket member 28a and a second
1G U-shaped bracket member 28b. The first bracket member 28a is
secured such as by threaded fastener and nut assemblies (not
shown) to a side wall 30 of the top member 22 to present a
vertically orientated mounting surface 31. The second bracket
member 28b is similarly secured to the base portion 24 via
15 conventional threaded nut and bolt assemblies (not shown) to
present a second, vertically orientated support surface 32. A
first pair of apertures 34 are formed in the support surface 32
and a second pair of apertures 36 are formed in the support
surface 32 which enable the entire powerhead apparatus 12 to be
20 secured to a horizontally extending frame portion of a land
vehicle, such as a snow thrower or tiller, which require a
horizontally disposed output shaft to drive the working implement
of the vehicle. Thus, the powerhead apparatus 12 can be mounted
in either a vertical or horizontal orientation without requiring
25 disassembly of the powerhead apparatus, modification thereto or
other manufacturing steps such as drilling, tapping holes, etc.,
prior to securing the powerhead apparatus to the specific land
vehicle or tool. The placement and construction of the secondary
mounting assembly 28 components are further such that disassembly
30 does not interfere with other components of the land vehicle
mounted in close proximity to the powerhead apparatus since the
overall footprint of the apparatus, as seen particularly well in
Figures 3 and 4, is not substantially increased by the secondary
mounting assembly 28.
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With further reference to Figures 2, 3 and 6, the
powerhead apparatus 12 further includes a removable interlock
assembly 38 and a charger interface circuit assembly 40 (Figure
6). The interlock assembly 38 is the subject of U.S. Patent No.
5,085,043, assigned to the assignee of the present application.
Briefly, the interlock assembly 38 includes aremovable "key" 42
which, when removed as shown in Figure 6, electrically disables
the electric motor 26 such that the motor 26, and thus the
powerhead apparatus 12, cannot be operated while an external
battery charger 44 is electrically coupled to the charger
interface circuit assembly 40. Accordingly, there is no~chance
of the motor 26 being operated while the battery 25 is being
charged by the external charger 44. When the key 42 is inserted
into the charger circuit assembly 40, the electric motor 26 is
enabled and a charging port 45 is physically blocked by a portion
of the key 42. The key 42, however, cannot be coupled while the
charger 44 is electrically coupled to the charger assembly 40.
Thus, the key 42 can only be inserted once an electrical jack 46
associated with the external charger 44 is uncoupled from the
charger circuit assembly 40. As a result, the powerhead
apparatus 12 cannot be operated (i.e., the motor 26 turned on)
when the battery charger 44 is coupled to the charger assembly
40, while the charger 44 is prevented from being coupled to the
powerhead apparatus while the key 42 is inserted. Thus, it is
impossible to turn-on the motor 26 of the powerhead apparatus 12
while charging the battery 25 and further impossible to hook-up
the charger 44 to the apparatus while the motor 26 is running.
The placement of the charger circuit assembly 40 further allows
quick and convenient access by the operator without requiring
removal of any other components positioned closely adjacent the
powerhead apparatus12.
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With reference now to Figure 7, the universal mounting
plate 16 is shown coupled to the electric motor of the powerhead
apparatus 12. The universal mounting plate includes a central
portion 48 which is separated by an outer perimeter portion 50
by a generally circular inner wall portion 52. A generally
circular outer wall 54 further circumscribes the inner wall
- portion 52. A plurality of upstanding support walls 56 are
formed in-between the inner wall portion 52 and the outer wall
portion 54 to further add rigidity and strength to the mounting
plate 16.
With reference to Figures 5, 7, 11 and 12 the outer
perimeter portion 50 includes a first plurality of apertures 58
spaced apart generally equidistant from one another while the
central portion 48 includes a second plurality of apertures 60
also spaced apart generally equidistant from one another. A
central aperture 62 (Figure 7) is formed at the center of the
mounting plate 16.
With brief reference to Figures 4-6 and 11, the central
aperture 62 allows a lower cover member 27 secured to a flux can
29 of the electric motor 26 to pass through the mounting plate
16. The apertures 60 allow the mounting plate 16 to be coupled
to the lower cover member 27 of the motor 26 (shown in Figure 11)
via conventional threaded bolts which extend through apertures
26d (Figures 11 and 12) to thus hold the motor 26 rigidly
relative to the mounting plate 16. The apertures 58 are
positioned to overlay the engine mounting holes (not shown) in
the deck 14 of the lawn mower 10 to allow the mounting plate 16
to be secured directly to the deck 14 via threaded bolts and nuts
to thus secure the entire apparatus 12 rigidly to the deck 14.
The universal mounting plate 16 is preferably formed from
a suitably high-strength material such as metal. Alternatively,
a high-strength plastic such as glass filled nylon could be used
and the mounting plate 16 formed by well-known inj ection molding
techniques in a suitably shaped injection molding die.
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Referring now to Figure 8, there is shown a universal
powerhead apparatus 80 in accordance with an alternative
preferred embodiment of the present invention. The powerhead
apparatus 80 is essentially identical to the apparatus 12 with
the exception that it is adapted to be powered directly by an AC
power source via a conventional AC power cord 82. The components
of the apparatus 80, which are identical to those described in
connection with the apparatus 12, have been indicated by like
reference numerals with a "prime" superscript designation. With
the apparatus 80, the key 42' of the interlock assembly 38' , when
removed, prevents the powerhead apparatus from being turned on.
Once the key 42' is inserted into the interlock assembly 38' , the
apparatus may be turned on by a suitable on/off switch disposed
preferably on a handle portion (not shown) of the lawn mower 10
shown in Figure 1.
Referring briefly to Figure 9, the powerhead apparatus 12
is shown forming a power source for a snow thrower 84. The
apparatus 12 is mounted such that its output shaft (not visible)
is mounted in a horizontal orientation to a drive mechanism 85
as needed to drive the snow throwing implement 86 of the snow
thrower 84 . _. r _ _.
With brief reference to Figure 10, the powerhead apparatus
12 is shown mounted in a horizontal orientation to drive a tiller
88. The brackets 28a and 28b of the secondary mounting assembly
28 are secured directly to a frame portion 90 of the tiller 88.
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The output shaft (not shown) of the powerhead apparatus 12
extends horizontally into a drive assembly 92 of the tiller 88,
which drives a tilling implement 94 rotationally about a
horizontally extending axis of rotation.
It will thus be appreciated that the preferred embodiments
of the present invention described herein provide for an electric
powerhead apparatus which may be powered by batteries or directly
from an AC power source., The preferred embodiments of the
present invention are further adapted to be quickly and easily
secured to a frame portion of a land vehicle, tool or pump, as
well as virtually any form of implement which would otherwise be
used with an internal combustion engine, without requiring
significant modification of the frame portion or rearrangement
of other-component parts originally designed to be in close
proximity to the power source. The preferred embodiments of the
powerhead apparatus are further adapted to be secured directly
to a frame portion of a land vehicle, tool or pump during factory
assembly or retrofittable to the device to replace an internal
combustion engine. Accordingly, the powerhead apparatus of the
present invention allows an electric power source to be used in
place of an internal combustion engine on a wide variety of land
vehicles or tools without significant modification to the frame
portion of such vehicle or other components thereof. The
powerhead apparatus of the present invention furthex produces
none of the undesirable airborne pollutants normally produced by
internal combustion engines nor require the periodic maintenance
typically required for gasoline powered engines.
Those skilled in the art can now appreciate from the
foregoing description that the broad teachings of the present
invention can be implemented in a variety of forms. Therefore,
while this invention has been described in connection with
particular examples thereof, the true scope of the invention
should not be so limited since other modifications will become
apparent to the skilled practitioner upon a study of the
drawings, specification and following claims.
