Note: Descriptions are shown in the official language in which they were submitted.
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A SMALL ENGINE COMBINATION SWITCH
FIELD OF THE INVENTION
The invention relates generally to a portable internal combustion engine.
BACKGROUND
Internal combustion engines and equipment driven thereby provide one
form of temporary yet reliable power, which is also mobile or portable, that
is usable in
many fields or industries including in hospitals, hotels, construction,
environmental
protection and even in residential use settings. Such internal combustion
engines may
be fueled by gasoline, diesel oil, natural gas or liquefied petroleum gas.
One drawback of small internal combustion engines, including equipment
driven thereby, relates to the operation and efficiency thereof. More
specifically, a
choke, fuel valve and ON/OFF switch are designed as separate independently
operable
components even though they cooperate for several functions. For example, to
start
the engine, firstly the ON/OFF switch is opened, secondly the engine is
choked, and
thirdly the fuel valve is opened (either manually or via an electric switch).
In another
example, to turn off the engine, both the ON/OFF switch and the fuel valve are
closed;
otherwise, an open fuel valve may lead to fuel leakage and consequently form a
fire
hazard. In yet another example, for prolonged storage, it is often necessary
to use a
tool to manually drain the fuel from the carburetor float bowl, else the
residual fuel may
become form a gummy sticky material which may spoil the carburetor.
SUMMARY OF THE INVENTION
It is therefore one aspect of the invention to provide a control combination
switch for a small engine.
According to an aspect of the invention there is provided a small engine
control combination switch comprises a rotary knob assembly which includes on
its
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backside a shaft operably coupled to a fuel valve, a trigger tab disposed at a
peripheral
location of the backside to engage an engine ON/OFF switch for stopping the
engine,
and a circumferentially extending rail with gradually increasing height for
adjusting
position of a choke via a choke cable which is supported for contact with the
rail of the
knob assembly.
According to another aspect of the invention there is provided a small
engine control combination switch comprising:
a knob assembly;
a bracket rotatably supporting the knob assembly on one side of the
bracket;
a choke cable supported on an opposite side of the bracket and operably
coupled to the knob assembly for controlling a choke of an engine;
the knob assembly including:
a front gripping portion on a front side of the knob assembly;
a backside portion of the knob assembly comprising a central shaft
about which the knob assembly is rotatable, and a rail disposed at a
peripheral location
of a backside of the knob assembly and extending about a circumference of the
backside portion of the knob assembly;
the rail of the knob assembly being disposed in contact with a tip of the
choke cable via a first hole defined in the bracket;
the rail having an increasing height relative to the backside of the knob
assembly about the circumference of the backside portion of the knob assembly
such
that rotation of the knob assembly acts to drive the tip of the choke cable
towards and
away from the knob assembly.
Preferably, the switch further includes a fuel valve which is operably
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coupled with the shaft of the knob assembly via a second hole defined in the
bracket
so as to control on and off states of the fuel valve.
Preferably, the switch further includes a trigger tab disposed at a
peripheral location of a backside of the knob assembly.
Preferably, the switch further includes an engine ON/OF F switch
operatively coupled to the engine to control an on-off state of the engine,
and the trigger
tab is arranged to contact the engine ON/OFF switch upon rotation of the knob
assembly so that the knob assembly is operable to control the on-off state of
the engine.
In the illustrated embodiment, with respect to a circumferential direction
of the knob assembly, the trigger tab is disposed adjacent a minimum height
end of the
rail.
Preferably, the switch further includes a choke wire guide mounted to the
bracket, which carries the choke cable.
Preferably, the switch further includes a stopper plate mounted in fixed
relation to the fuel valve, a spring supported at one end on the stopper
plate, a steel
ball which is carried at an opposite end of the spring in opposite relation to
the stopper
plate, and the backside portion of the knob assembly defining sockets disposed
at
angularly spaced locations of the shaft and having smaller diameters than a
diameter
of the steel ball such that the steel ball is biased by the spring to be
received in a select
one of the sockets to define predetermined rotational positions of the knob
assembly
relative to the bracket.
Preferably, the bracket includes a panel and the knob assembly is
arranged in the panel.
In the illustrated embodiment, the rail comprises a first portion having the
increasing height which increases from a minimum height of the rail to a
maximum
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height of the rail relative to the backside of the knob assembly and a second
portion of
the rail having a uniform height equal to the maximum height of the rail.
Advantages of such arrangements of the present invention include:
1. Rotation of the knob assembly can alone act to control the choke,
the fuel valve and the engine ON/OFF switch which simplifies operation and
improves
efficiency;
2. The function of burning residual fuel in the carburetor is
incorporated into the switch so that a manual drain of the carburetor is not
separately
necessitated when it is desired to store the engine for a prolonged period of
time;
3. A simple and compact structure providing convenient, safe and
reliable operation and that is widely applicable in small engines and
equipment driven
thereby is provided.
According to another aspect of the invention there is provided a small
engine control combination switch comprising:
a fuel switch;
a bracket having a first hole and a second hole;
a knob assembly comprising a fixed plate, a rotating shaft which passes
through the second hole to connect with the fuel switch for driving the fuel
switch on or
off;
an engine controlling means comprising a convex block on the fixed plate,
an ON/OFF switch arranged on the bracket, the ON/OFF switch is matched with
the
convex block to control the engine;
a choke controlling means comprising a rail on the fixed plate, a choke
wire guide is provided on the bracket, a choke cable is in the choke wire
guide and
passes the first hole to contact with the rail, a reset spring is installed at
an end of the
Date Recue/Date Received 2021-02-02
4a
choke cable for making the end of the choke cable to keep touch on the rail,
the rail is
gradually increased in height, when the fixed plate of the knob assembly is
turned the
rail is turned too, thereby the rail drives the choke cable to move up and
down to control
the choke;
the bracket is provided with a panel and the knob assembly is set within
the panel, the panel is marked with labels of Start, Run, Run Out of Fuel and
Stop;
when the knob assembly is in the Start position, the fuel switch has been
partially open, the choke in a fully closed state, the ON/OFF switch is in an
off state;
when the knob assembly is within a scope from the Start to Run, the fuel
switch and the choke gradually opened to the maximum position, arbitrary
positions
within this range;
when the knob assembly is in the Run position, the choke and fuel switch
fully open;
when the knob assembly is in the Fuel Shut-Off position, the fuel switch
is fully closed, the choke valve remains fully open, the engine continues to
run,
carburetor fuel is burnt, thus avoiding use of tools to manually put the
carburetor fuel
out;
when the knob assembly is in the Stop Position, the ON/OFF switch is
contacted by the convex block to be turned on to make the engine flameout.
In one embodiment, the small engine control combination switch
comprises a stopper plate is on the fuel switch, a spring is arranged on the
stopper
plate, a steel ball is arranged on the spring, a plurality of grooves are in
the fixed plate,
which are matched with the steel ball respectively, and an outer diameter of
the steel
ball is larger than a pore diameter of the groove.
Date Recue/Date Received 2021-02-02
4b
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in conjunction with the accompanying
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1
drawings in which:
Figure 1 is a schematic view of an arrangement of the present invention;
Figure 2 is an exploded view of the arrangement of Figure 1;
Figure 3 is a schematic view of a knob assembly of the arrangement of
Figure 1; and
Figure 4 is a schematic view of a panel of the arrangement of Figure 1.
In the drawings like characters of reference indicate corresponding parts
in the different figures.
Also, in the above mentioned drawings, the following parts are identified
by the corresponding reference numerals: 1-knob assembly, 101-rail, 102-
rotating
shaft, 103-sockets, 104-fixed plate, 105-trigger tab, 106-rotating part, 2-
bracket, 201-
Date Recue/Date Received 2021-02-02
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first hole, 202-second hole, 3-nut, 4-choke cable, 41-choke cable guide, 5-
fuel valve,
6-stopper plate, 7-spring, 8-steel ball, 9-ON/OFF switch, 10- panel.
DETAILED DESCRIPTION
Reference is made to the accompanying drawings in which is shown an
illustrative embodiment of the invention from which its features and
advantages will be
apparent.
A small engine control combination switch includes a knob assembly 1, a
bracket 2 rotatably supporting the knob assembly 1 on one side of the bracket,
and a
choke cable 4 supported on an opposite side of the bracket 2 and operably
coupled to
the knob assembly 1 for controlling a choke of an engine (not shown). The knob
assembly 1 comprises a front gripping portion 106 on a front side of the knob
assembly
and a backside portion 104 of the knob assembly 1 which includes a central
shaft 102,
a trigger tab 105 disposed at a peripheral location of a backside of the knob
assembly
1, and a rail 101 disposed at a peripheral location of the backside of the
knob assembly
.. 1 and extending about a circumference of the backside portion of the knob
assembly.
The rail 101 of the knob assembly 1 is disposed in contact with a tip of the
choke cable
4 via a first hole 201 defined in the bracket 2. The rail 101 has a gradually
increasing
height relative to the backside of the knob assembly 1 about the circumference
of the
backside portion 104 of the knob assembly 1 such that rotation of the knob
assembly 1
which is actuated by a user at the front gripping portion 106 acts to drive
the tip of the
choke cable 4 towards and away from the knob assembly, for example up and
down.
The switch further includes a choke wire guide 41 mounted to the bracket 2,
which
carries the choke cable 4. A reset spring is installed at the end of choke
cable 4 so that
the point of contact between the choke cable 4 and the rail 101 is maintained
in sliding
.. contact, so as to control opening and closing of the choke'.
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Also, the switch further includes a fuel valve 5 which is operably coupled
with the shaft 102 of the knob assembly 1 via a second hole 202 defined in the
bracket
2 so as to control on and off states of the fuel valve 5.
The bracket 2 is provided with a panel 10 and the knob assembly is set
within the panel 10 so as to be arranged in the panel 10. The panel 10 is
marked at
various angularly spaced locations about the knob assembly 1 with labels
including
"Start", "Run", "Run Out of Fuel" and "Stop".
The switch also includes an engine ON/OFF switch 9 which is operatively
coupled to the engine to control an on-off state of the engine and is arranged
for contact
with the trigger tab 105 so that the knob assembly is operable to control the
on-off state
of the engine. The ON/OFF switch 9 may be mounted on the bracket 2. Upon
rotation
of the knob assembly 1 via the front gripping portion 106, the trigger tab 105
on the
backside portion 104 contacts the ON/OFF switch 9 to control the engine. When
the
trigger tab 105 and ON/OFF switch engage, the ON/OFF switch 9 is turned on,
and
consequently the engine turns off.
As more clearly shown in Figure 2, there is provided a stopper plate 6 in
the form of a bracket mounted in fixed relation to the fuel valve 5, a spring
7 which is
supported at one end to the stopper plate 6, and a steel ball 8 which is
carried at an
opposite end of the spring 7 in opposite relation to the stopper plate. The
spring 7 and
the steel ball 8 are received in a tubular guide G formed on the bracket 2 so
as to
position the steel ball at a fixed location with respect to the knob assembly
1. The
backside portion 104 of the knob assembly 1 defines a plurality of sockets 103
disposed
at angularly spaced locations about the shaft 102. The sockets 103 are sized
in
diameter to be smaller than a diameter of the steel ball 8. Thus, the steel
ball 8 is
biased by the spring 7 against the backside portion 104 of the knob assembly 1
to
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cooperate with the sockets 103 formed therein to define predetermined
rotational
positions of the knob assembly 1 relative to the bracket 2.
A process of operating the switch includes the following:
1. Start Position
In the initial position of the knob assembly 1 which is the "Start"
position, the fuel valve 5 is partially open, the choke is disposed in a fully
closed state
(i.e., obstructing air flow into the carburetor) and the ON/OFF switch 9 is in
an off state.
Upon rotation of the knob assembly 1 from the "Start" to the "Run" position,
both the
fuel valve 5 and the choke gradually open to a maximum (open) position, and
anywhere
within this range of angular positions of the knob assembly the operator may
manually
or electrically start the engine according to environmental conditions.
2. Operating Position
This corresponds to "Run", at which position the choke and the fuel
valve 5 are fully open.
3. Storage Position
The Storage Position is achieved by continuing to rotate the knob
assembly 1 past "Run", whereby the fuel valve 5 closes slowly while the choke
remains
fully open. When the user does not intend to use the engine for an extended
period of
time, the knob assembly 1 may be set to the "Run Out of Fuel" position in
which the fuel
valve 5 is fully close yet the choke remains fully open, such that the engine
continues
to run until the residual fuel in the carburetor is substantially burnt off.
Thus, a step of
manually draining the fuel from the carburetor, using other tools, in
preparation for
"storage" of the engine may be omitted.
4. Stop Position
By rotating the knob assembly 1 past the "Run Out of Fuel" position
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to the "Stop" position, the trigger tab 105 contacts the ON/OFF switch 9,
which is
consequently turned on causing the engine to flameout and the device driven
thereby
to stop running.
Arrangements of the present invention may overcome the defects of the
prior art by providing a single rotary knob assembly 1 which can realize
control of the
choke cable 4, fuel valve 5, and ON/OFF switch 9, thereby simplifying
operation by a
user of the engine by controlling all the choke, starting, running and
flameout, and
improving the operating efficiency, as well as incorporating a feature whereby
residual
fuel in the carburetor is burnt off.
As more clearly shown in Figure 3, the trigger tab 105 of the illustrated
embodiment is a raised projection on the backside of the knob assembly
1,relative to
the backside of the knob assembly, as measured from a flat portion 108 of the
backside
portion 104. The flat portion 108 defines a minimum height of the backside of
the knob
assembly 1 in the illustrated embodiment.
Referring to Figure 3, the sockets 103 are located generally radially
inwardly of the flat portion 108, trigger tab 105 and the rail 101.
Referring to Figures 1 and 3, in the illustrated embodiment the rail 101
comprises a first height-varying portion 101A along which the height of the
rail 101
increases from a minimum height of the rail to a maximum height of the rail
relative to
the backside of the knob assembly 1 and a second maximum height portion 101B
of
the rail which has uniform height equal to the maximum height of the rail. In
the
illustrated embodiment, the minimum rail height is equal to the minimum height
of the
backside of the knob assembly as defined by the flat portion 108. The height-
varying
rail portion 101A is thus inclined from the minimum rail height to the maximum
rail
height.
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Still referring to Figures 1 and 3, the trigger tab 105 is located adjacent a
minimum height end of the rail 101, with respect to a circumferential
direction of the
knob assembly 1. In the illustrated embodiment the height-varying portion 101A
of the
rail 101 is spaced from the trigger tab 105 by a third minimum height portion
101C of
the rail which has uniform height equal to the minimum height of the rail,
which is zero
as the minimum rail height is equal to the minimum height of the backside of
the knob
assembly 1 as defined by the flat portion 108.
As such, in use, when the knob assembly 1 of the switch is arranged in
the "Start" position, the minimum height portion 101C of the rail 101 is
disposed in
contact with the choke cable 4 corresponding to the fully closed state of the
choke. As
the knob assembly 1 is rotated through angular positions intermediate the
"Start" and
"Run" positions indicated on the panel 10 as shown more clearly in Figure 4,
the height-
varying portion 101A of the rail is in contact with the choke cable 4. From
the "Run"
position to the "Stop" position, the maximum height portion 101B of the rail
is disposed
in contact with the choke cable 4. In the "Stop" position the trigger tab 105
is disposed
in contact with the ON/OFF switch 9 so as to shut off the engine.
The principles and features of this invention may be employed in various
and numerous embodiments without departing from the scope of the invention.
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