Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MULTI-SPEED WINCH WITH
CONSTANT MESH GEARING SYSTEM
Background of the Invention
I. Field of the Invention
This invention relates to winches for winding a cable
strap or rope to pull vehicles such as watercraft and, in
particular, to a winch with a gearing system to change gear ratios
for operation which does not require shifting between different
gears providing constant meshing of the gears for improved
durability.
II. Description of the Prior Art
Manual winches are popular mechanisms for pulling
vehicles such as watercraft onto their trailers or other storage
facilities. The typical winch inccrpcrates a crank with a crank
gear mounted to the crankshaft and in engagement with the drum
upon which the line is wrapped. Rotation of the crank and crank
gear causes the drum to rctate collecting the line on the drum.
The crank effort is dictated by the gear ratic between t~e crank
gear and the drum gear. Typically the consumer must purchase the
winch which incorporates the gear ratio required for a particular
application.
While clutch and transmission mechanisms have developed
means of changing gear ratios, such complex mechanisms are nGt
suitable for relatively inexpensive and simple winch assemblies.
In such transmissions, the gear ratios are kept in cGnstant mesh
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with a drive shaft moving ketween the gear sets. However, these
transmissions are heavily dependent upon hydraulics to shift
between gear ratios. In view of the simple nature of a manual
winch, extraordinary mechanisms to shift between gear ratios would
complicate these winches.
Summary of the Present Invention
This invention relates to a multi-speed winch receiving
a line, said winch comprising: a housing; a winch drum rotatably
supported within said housing for receiving the line; a crankshaft
rotatably supported wit~in said housing and receiving crank means
for rotating said crankshaft, said crankshaft longitudinally
movable to axially displace a key means on said crankshaft; at
least two rotatable members mounted to said crankshaft for selective
rotation therewith upon engagement of said key means of said crank-
shaft; and drive means in rotatable connection with said winch drum
and said at least two rotatable members for transmitting rotation
of said at least two rotatable members to said winch drum.
The present invention overcomes the disadvantages of the
prior known winches by providing a constant mesh gearing system
which allows shifting between gear ratios by longitudinally moving
the
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crankshaft for operation in accordance with performance
requirements.
The winch of the present invention includes a winch housing to
which the components are mounted including a winch drum upon which
a winch line is wrapped. The winch drum includes a gear for
rotatably driving the drum on a drum shaft mounted to the housing.
Also mounted to the housing in parallel alignment with the drum
shaft is a crankshaft and a driveshaft. The winch cranks are
attached to the crankshaft for rotation of the crankshaft to
rotatably drive one of at least two different crank gears mounted
coaxial with the crankshaft. The crankshaft includes a fixed gear
tooth which can be shifted between the crank gears to selectively
drive a single crank gear. Detent means on the crankshaft prevents
inadvertent shifting of the crankshaft between crank gears. The
crank gears are in constant mesh with drive gears forming the
different gear ratios. The drive gears are mounted to the drive
shaft which also includes a ratchet gear in constant mesh with the
winch gear such that rotation of the drive gears rotates the
ratchet gear and winch gear.
Longitudinal shifting of the crankshaft will cause the fixed
gear tooth to engage the hub of one of the crank gears depending
upon the desired gear ratio. Once engaged with the hub, rotation
of the crank will cause the selected crank gear and its meshed
drive gear to rotate in accordance with the gear ratio. Rotation
of the drive gear in turn rotates the drive shaft, ratchet gear and
winch gear for rotation of the winch drum. Thus, despite changing
gear ratios the crank and drive gears remain in constant mesh with
only a specific set of gears being chosen by shifting the
crankshaft. In order to provide noiseless operation of the ratchet
system which locks the winch against reverse rotation, a standoff
is mounted to the ratchet pawl which holds the ratchet pawl away
from the ratchet gear eliminating the well-known ratchet noise of
typical winches.
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Other objects, features, and advantages of the invention will
be apparent from the following detailed description taken in
connection with the accompanying drawing.
~rief Descri~tion Of The Dr~wing
The present invention will be more fully understood by
reference to the following detailed description of a preferred
embodiment of the present invention when read in conjunction with
the accomp~nying drawing, in which like reference characters refer
to like parts throughout the views and in which:
FIGURE 1 is a side elevational view of a winch with a constant
gearing system embodying the present invention;
FIGURE 2 is a cross-sectional view of the winch taken along
lines 2-2 of Fig. 1;
FIGURE 3A and 3B are cross-sectional views of the gear hubs
with the crankshaft tooth drive; and
FIGURE 4 is a cross-sectional view of winch housing, winch
drum and drum bearing of the winch.
Det~ile~ Descri~tion Of A Preferred
~mho~iment Of The Present Tnvention
Referring first to Figure 1, there is shown a winch 10
embodying the present invention. The winch 10 is adapted to
rotatably retract a flexible line such as a rope or cable for
pulling heavy objects. In a typical application, the winch 10 is
used to pull a watercraft onto its trailer or other storage
structure. Through the use of gear ratios, little effort is needed
to pull a heavy object. However, the prior known winches had a
fixed gear ratio built into the winch which could not be changed.
The present invention allows the gear ratio to be changed for
multi-speed operation.
The winch 10 of the present invention includes a housing 12 to
which the components of the winch 10 are mounted and which
facilitates attachment of the winch 10 to a support structure. The
housing 12 preferably comprises a metal frame 14 having opposing
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side walls 16. Rotatably mounted to side walls 16 of the housing
12 is a winch drum 18 upon which a tow line (not shown) is
rotatably wrapped. As best shown in Figure 4, the winch drum 18 is
secured to a drum bearing 20 rotatably mounted to a winch shaft 22
secured at opposite ends to the housing 12. Mounted to the drum 18
for rotation therewith is a winch gear 24.
Manual operation of the winch 10 is conducted through at least
one crank 26 connected to a crankshaft 28 rotatably mounted to the
side walls 16 of the housing 12 to extend through the housing 12.
The crankshaft 28 is longitudinally movable to shift between gear
ratios in accordance with the present invention. Coaxially mounted
on the crankshaft 28 is at least two crank gears 30 corresponding
to the gear ratios of the winch 10. For clarity of understanding,
the present invention will be described in connection with a first
crank gear 32 and a second crank gear 34 selectively drivable by
the crankshaft 28. However, additional crank gears may be employed
to provide a wider range of gear ratios. Each of the crank gears
32 and 34 include a hub slot 36 and 38 adapted to selectively
receive a crank tooth 40 fixedly formed on the crank shaft 28
(Figs. 3A and 3B) in order to rotatably drive the respective crank
gear 30 upon rotation of the crankshaft 28.
The crankshaft 28 also includes detent means 42 preferably
formed in an opposite end of the crankshaft 28. The detent means
42 includes a pair of detents 44 formed on the crankshaft 28
corresponding to the spacing and number of crank gears 30. The
detents 44 selectively receive ball bearings 46 biased against the
crankshaft 28 by springs 48. The force of the springs 48 can be
overcome to move the crankshaft 28 longitudinally but the bearings
46 prevent inadvertent movement of the crankshaft 28 during
operation thereby ensuring that the crank tooth 40 will be engaged
with the corresponding crank gear 30.
Rotatably mounted to the housing 12 parallel to the drum shaft
22 and the crankshaft 28 is a drive shaft 50. Fixedly mounted to
the drive shaft 50 for simultaneous rotation are drive gears 52
corresponding to the number of crank gears 30. In accordance with
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the preferred embodiment, a first drive gear 54 mounted to the
drive shaft 50 is in driving engagement with the first crank gear
32 and a second drive gear 56 is in driving engagement with the
second crank gear 34. The size of the drive gears 54 and 56 is
dictated by the size of the crank gears 32 and 34 to ensure meshing
engagement between the gears. Accordingly, rotational drive is
transferred from the crankshaft 28 and crank gears 30 to the drive
gears 52 and drive shaft 50.
Also mounted to the drive shaft 50 for rotation therewith is
a ratchet gear 58 and a ratchet wheel 60. The ratchet gear 58
drivingly engages the drum gear 24 to transfer rotation to the drum
18. The ratchet wheel 60 is engaged by a ratchet pawl 62 to
prevent unwinding of the winch 10 until desired. The pawl 62 is
pivotably mounted to a bracket 64 to repeatedly engage the teeth of
the ratchet wheel 50 facilitating rotation in a first direction
but preventing rotation in the opposite direction. Associated with
the ratchet pawl 62 is a standoff 66 which allows "noiseless"
operation of the winch 10. In the conventional winch 10, the
chatter or clicking of the pawl is widely recognized. This results
from the pawl falling between the teeth of the ratchet wheel 60.
During normal cranking, the standoff 66 holds the pawl 62 away from
the ratchet wheel 60. As cranking begins, the standoff 66 engages
a circular outer surface 68 of the ratchet wheel 60 to pivot the
pawl 62 outwardly away from the ratchet wheel 60.
Operation of the present invention allows selection between
different gear ratios of the winch 10 by simply shifting the
crankshaft 28. In accordance with the application, the user can
shift the crankshaft between the low gear ratio associated with
crank gear 32 and the high gear ratio associated with crank gear
34. When low gear is desired, the crank tooth 40 is engaged with
the hub 36 of the first crank gear 32. When high gear is desired,
the crankshaft 28 is moved longitudinally overcoming the detent
means 42 to engage the crank tooth 40 with the hub 38 of the second
crank gear 34. With either crank gear 30 engaged, rotation of the
crank 26 will transfer rotation from the crank gears 30 to the
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drive gears 52 which transfers rotation to the ratchet gear 58 and
drum gear 24 to wind the line onto the drum 18. During cranking,
the standoff 66 maintains the pawl 62 away from the ratchet wheel
60. When cranking stops, the standoff pivots outwardly allowing
the pawl 62 to engage ratchet wheel 60 preventing further rotation
of the winch drum 18. Thus, the present invention allows
convenient shifting between gear ratios while maintaining the gears
in constant mesh eliminating stripping and other damage to the
gears.
The foregoing detailed description has been given for
clearness of understanding only and no unnecessary limitations
should be understood therefrom as some modifications will be
obvious to those skilled in the art without departing from the
scope and spirit of the appended claims.
What is claimed is:
