Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a hand control system for a
motorized implement such as a snowblower, tiller or lawn mower.
Motorized hand implements such as snowblowers, lawn
mowers and tillers are often handled by unskilled operators and
therefore can be dangerous unless they are very carefully
designed. They are generally controlled by a combination of
levers mounted on a handle. The levers control functions such
as engine speed, engagement of driving wheels, and engagement
of a blade or auger, and the handle is used to steer the
implement. The handle often consists of two spaced-apart metal
tubes, bent so that the ends of the handle are parallel to the
ground, ~acing rearwardly, but operator control can be improved
and fatigue lessened by providing a one-piece handle which is
generally U-shaped when viewed from above and which may be
gripped in several different ways and at several places along
its length. Furthexmore/ control of the implement can be
improved with a U-shaped handle, parl:icularly when turning the
implement, if the operator can grip l:he handle at one side or
,`~ the other, thus exerting lèverage on the handle.
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~ 20 The control levers are usually provided with a safety
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`~ "deadman" feature, so that the drive wheels, auger or blade is
disengaged when the control levers are released by the operator
in case the operator should fall or lose his grip on the
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implement. This may give rise to problems when the implement
is in use because the operator may wish to remove his hand from
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one lever, for instance the drive control, in order to adjust
another lever, for instance engine speed. If he does so, at
least one of the functions controlled by a deadman lever will
stop, which may be inconvenient. As a result of this potential
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inconvenience, the operator may lock or jam the lever,
defeating this safety feature and possibly causing a serious
; accident.
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Some control systems partly overcome this problem by
ensuring that one of the levers is held down when the other is
depressed, thus permitting one-handed operation by depressing a
second lever only. The disadvantage to this system is that the
operator cannot chose to use the second lever independently,
for when it is depressed so is the first lever.
- Another system has two levers placed in proximity to
each other so that they may be operated independently by one
hand on each lever, or operated together, held by a single hand
positioned between the two leversO The disadvantage to this
system is that the operator's hand must be positioned between
the two levers to grasp closely opposed ends of the levers and
cannot be moved along the handle to achieve a more convenient
position to guide the machine.
It is to be emphasized that an inconvenience of this
nature to the operator who is not necessarily a skilled
professional may result in the operator jamming the deadman
lever and defeating the safety features which are designed into
the implement control mechanism or may lead to premature
fatigue on the part of the operator. Thus, increased
; convenience results in safer, less tiring and more comfortable
operation of the implement.
~ This invention provides a control system for a
motorized implement comprising: a U-shaped handle; two control
levers pivotally mounted on the U shaped handle, one end of
eaah being pivotally moveable from a first inoperative position
~ distal from the handle to a second inoperative position
; proximate to the handle; a U-shaped bail, pivotally mounted on
the U-shaped handle~ the bight of which being pivotally
moveable from a first position distal from the handle to a
second position proximate to the handle, said bail adapted to
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bear against the control levers and move them from their first
positions to their second positions when the bail is pivoted
from its first position to its second position; and means for
normally biasing the control levers and means for biasing the
U-shaped bail to their first pocitions distal from the handle,
whereby each control lever may be independently pivoted from
its first to its second position, or both control levers may be
conjointly pivoted by the bail from their first to their second
positions.
In one aspect of the invention, the control levers are
pivotally mounted in proximity to the pivotal mounting of the
bail. In another, the relative positions of the levers are
adapted so that if the bail is squeezed towards its second
position proximate the handle, first one lever and then the
other is moved from its first towards its second activated
position. This aspect allows one function to be engaged before
the other. -
It will be seen that this invention allows the
operator to change his grip on the handle to avoid fatigue and
to grip at one end or the other of the handle. In addition,
the control permits single handed use of the machine.
Referring to the drawings,
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Figure 1 is a perspective view of a snow blower
showing an embodiment of the invention
mounted thereon;
Figure 2 is a perspective view of the same embodiment
in more detail;
Figure 3 is a partially exploded view of a lever and
bail pivotal mounting on the handle;
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Figure 4 is a side elevation of the embodiment shown
in Figure 2; and
Figure 5 is a side elevation of another embodiment of
the invention
With reference to Figures 1 and 2 of the drawings, the
hand control system of the present invention comprises a
generally U-shaped, horizontally-disposed, tubular handle 10
having side extensions 12, 14 extending downwardly for
securement to the opposite sides of snow blower depicted by
numeral 16. Although the description of the hand control
system of the invention will proceed with reference to a snow
blower, it will be understood that the hand control system can ~ :
be incorporated with and comprise the hand control system o~ a
garden tiller, lawn mower or the like motorized implement.
Two control levers 18, 20 engage the auger 22 and ~ .
drive wheels 24 respectively of the snowblower, acting through
linkages 26 and 28. The throttle 30 which controls engine
speed and gear shift selector 32 are located separately on
console 34. The discharge chute 36 is turned to a desired
direction by a screw control, not shown.
Control levers 18, 20 are pivotally mounted on handle
10, preferably one on each side thereof on side portions 38,
40, as shown most clearly in Figure 2, by means of pins 42 :
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secured by caps 44 threaded thereon passing through the handle
. portions 38, 40. U-shaped bail 46 is pivotally connected to :~ -
the side portions 38, 40 of handle 10 by pins 42 common to
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~ levers 18, 20. The bail 46 and levers 18, 20 thus pivot about
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the same axes 50, 52, axes 50, 52 normally being in co-axial
alignment. ~ : `
Bail 46 is semi-circular in section having a reduced
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radius in centre section or bight 56 to closely abut and
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envelop the web 58 of handle 10 and an enlarged radius in side
sections 60, 62 to accommodate levers 18, 20 which are curved
in cross-section to closely abut and envelop side portions 38,
40 of handle 10. Pins 42 pass through openings 68 formed in
lugs 70 extending from side sections 60, 62 of bail 45. A
torque spring 72 mounted on at least one pivot pin 42, Figure
3, is adapted to operatively engage lever 18 and bail 56 such
that the bail 46 and lever 18 are urged angularly apart about
axis 50.
Each of levers 18, 20 is urged to a first, at-rest
position distal, i.e. remote, from handle 10 by means of
respective linkages 26, 28 which are urged downwardly by
tension springs 47 or the like biasing means, well known in the
art. Levers 18, 20 thus are normally biased to their
respective first at-rest inoperative distal positions shown in
Figure 2 by linkages 26, 28 and bail 46 normally i5 biased to
its first at-rest inoperative distal position by one or more
torque springs 72. A second torque spring, not shown, may be
operatively inserted between lever 20 and bail 46 to in like
manner further urge the levers and bail 46 angularly apart.
The use of a single torque spring 72, such as for
lever 18, can result in preliminary depression of lever 18
relative to lever 20 by depression of bail 46 provided the
biasing means for linkage 26 is weaker than torque spring 72.
Thus, the function controlled by lever 18, such as for example
auger 22, can be actuated prior to the function controlled by
lever 20, such as drive wheels 24. Torque springs 72 of
different strengths may be used, one for each of levers 18, 20,
wherein the uses of a torque spring for lever 18 weaker than
30 the torque spring for lever 20, provided the biasing means for ---~
linkages 26, 28 are weaker than both torque springs, permits
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lever 18 to be depressed prior to the depression of lever 20 by
actuation of bail 46 against handle 10. Auger 22 thus can be
actuated prior to drive wheels 24 by slowly actuating bail 46.
Torque spring 72 can be weaker than the biasing means
connected to linkage 26 such that actuation of bail 46 does not
actuate lever 18 until bail 46 abuts lever 18, as depicted in
Figure 4. Lever 18 can thus be pivotted from the at-rest
distal position shown by solid lines through position 18a to a
second operative position 18b as shown by gho$t lines.
:: 10 Alternatively, lever 18 can be positioned at a higher
angular at-rest position, as shown in Figure 5, rela:tive to
lever 20, such that lever 18 is actuated by abutment with bail
46 prior to actuation of lever 20, thereby actuating for
example auger 22 prior to drive whee:Ls 24.
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The operator can thus depress both levers 18, 20 at
the same time with one hand, by hold:ing the bail 46 against the
: handle 10, and the operator will have a free hand to change
engine speed or the direction of the snow discharge. He can
also grasp the handle at various points with one or both hands
while holding the bail down to ~nable him to steer or control
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the implement more easily while~maintaining the controls~
: ~ operative. In addition, each control lever can be operated
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independently by the operator inserting a hand between bail 46
and handle 10. For instance, the auger control lever 18 can be ~
actuated to run the auger to clear it of snow without engaging ~ ; :
the wheels, and the wheel control~lever 20 can be engaged to
manoeuvre the snowblower without the auger running~ If any one
of the levers is released, the function controlled by the lever
will stop since the lever will automatically be returned to its
at-rest disengaged or inoperative position by spring 47. If
the bail 46 is released, and neither lever 18 or 20 is
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individually actuated, both levers will return to their
disengaged positions and both functions will cease. The
control system of the invention is thus convenient enough to
use that operators will not be as likely to defeat these safety
features.
Although the embodiment is described as it may be used
with a snow blower, it can be used with a tiller, a lawn mower,
or the like motorized implement if it were desired to arrange a
blade or other first function separately from the wheels and to
provide the operator the option of controlling both functions
- together with a single hand, sequentially if desired, or
independently with both hands.
It will be understood that modifications can be made
in the embodiment of the invention illustrated and described
herein without departing from the scope and purview of the
invention as defined by the appended claims.
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