U.S. patent number 3,799,005 [Application Number 05/317,793] was granted by the patent office on 1974-03-26 for drum winch.
Invention is credited to Georg Koehler.
United States Patent |
3,799,005 |
Koehler |
March 26, 1974 |
DRUM WINCH
Abstract
The present drum winch is especially suitable for use on sailing
vessels and comprises in its basic concept two pairs of planetary
gear wheels which cooperate with a drive wheel, a disk, and a jack
wheel whereby a large step-up ratio may be accomplished in one
direction of rotation of the drum shaft. In addition, a slipping or
torque release clutch may be arranged operatively between the jack
wheel and the disk and a braking action may be applied to the jack
wheel by means of pawls and ratchet wheels in one rotational
direction whereby a large step-up ratio is obtained in one
rotational direction while in the opposite rotational direction a
1:1 transmission or a large reduction or step-down ratio is
obtained. In further modification worm gear means may be provided
which are connected to or coupled with the jack wheel when the gear
is driven through the disk or which are connected to or coupled
with the disk when the gear is driven through the jack wheel
whereby an additional large step-down ratio is accomplished for a
sensitive back and forth rotation of the winch.
Inventors: |
Koehler; Georg (813) Starnberg,
DT) |
Family
ID: |
5847899 |
Appl.
No.: |
05/317,793 |
Filed: |
December 22, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Jun 16, 1972 [DT] |
|
|
2229340 |
|
Current U.S.
Class: |
475/12; 254/344;
254/354 |
Current CPC
Class: |
B66D
1/225 (20130101); B66D 1/04 (20130101) |
Current International
Class: |
B66D
1/02 (20060101); F16h 005/52 (); F16h 057/16 ();
B66d 001/30 () |
Field of
Search: |
;254/150
;74/812,792,626 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McKeon; Arthur T.
Attorney, Agent or Firm: Fasse; W. G.
Claims
What is claimed is:
1. In a drum winch wherein a drum is rotatably mounted relative to
a drum shaft which shaft is rotatable selectively in both
directions, said drum being rotatable by toothed wheel gear means
including a ratchet mechanism whereby the direction of drum
rotation is the same independent of the direction of shaft rotation
and whereby due to said ratchet mechanism the drum may be rotated
with different rotational speeds depending upon the direction of
rotation of the drum shaft, and wherein releasable brake means are
arranged for cooperation with said drum when the drum rotates
reversely, the improvement comprising a disk, first means for
controlling the position of said disk relative to said drum shaft,
a first pair of planetary gear wheels, means for rotatably
supporting said first pair of planetary gear wheels in said disk, a
second pair of planetary gear wheels, means for rotatably
supporting said second pair of planetary gear wheels in said disk,
jack wheel means, second means for controlling the position of said
jack wheel means relative to said drum shaft, said first and second
pairs of planetary gear wheels being arranged relative to said jack
wheel means for intermeshing with the jack wheel means, drive gear
means coupled to said drum, one of said pairs of planetary gear
wheels being arranged for coupling said jack wheel means to said
drive gear means in a step-up sense, the other of said pairs of
planetary gear wheels being arranged for coupling said jack wheel
means to said drive gear means in a reduction sense, said first and
second pairs of planetary gear wheels being arranged to counteract
each other for any rotational direction of the drum shaft, said
ratchet mechanism being arranged for interrupting the driving
connection between one or the other of the pairs of planetary gears
and the respective drive gear means in response to the rotational
direction of the drum shaft.
2. The drum winch according to claim 1, wherein said toothed wheel
gear means comprise sun and planetary gear means.
3. The drum winch according to claim 1, wherein said first means
for controlling the position of said disk relative to said drum
shaft comprise means for securing said disk on said drum shaft to
rotate with said drum shaft.
4. The drum winch according to claim 3, wherein said second means
for controlling the position of said jack wheel means relative to
said drum shaft comprise means for arresting the jack wheel means
against rotation, said drum shaft being rotatable relative to said
jack wheel means.
5. The drum winch according to claim 3, wherein said second means
for controlling the position of said jack wheel means relative to
said drum shaft comprise brake means for applying a braking force
to said jack wheel means said drum shaft being rotatable relative
to said jack wheel means.
6. The drum winch according to claim 1, wherein said second means
for controlling the position of said jack wheel means relative to
said drum shaft comprise means for securing said jack wheel means
to said drum shaft to rotate with said drum shaft.
7. The drum winch according to claim 6, wherein said first means
for controlling the position of said disk relative to said drum
shaft comprise braking means for applying a braking force to said
disk, said drum shaft being rotatable relative to said disk.
8. The drum winch according to claim 6, wherein said first means
for controlling the position of said disk relative to said drum
shaft comprise arresting means for arresting the disk, said drum
shaft being rotatable relative to said disk.
9. The drum winch according to claim 1, wherein said jack wheel
means comprise a small sun wheel and a large ring wheel rigidly
connected to each other, said drum winch further comprising means
for coupling one of said pairs of planetary gear wheels to the
large ring wheel and means for coupling the other pair of said
planetary gear wheels to the small sun wheel.
10. The drum winch according to claim 9, wherein said large ring
wheel comprises radially inwardly facing gear teeth whereas said
small sun wheel comprises radially outwardly facing gear teeth.
11. The drum winch according to claim 1, wherein said drive gear
means comprise a small sun wheel and a large ring wheel rigidly
connected to each other, said drum winch futher comprising means
for coupling one of said pairs of planetary gear wheels to the
large ring wheel and means for coupling the other pair of said
planetary gear wheels to the small sun wheel.
12. The drum winch according to claim 11, wherein said large ring
wheel comprises radially inwardly facing gear teeth whereas said
small sun wheel comprises radially outwardly facing gear teeth.
13. The drum winch according to claim 1, wherein the jack wheel
means comprise a first large ring wheel with radially inwardly
facing gear teeth and a first small sun wheel with radially
outwardly facing gear teeth, said drive gear means comprising a
second large ring wheel with radially inwardly facing gear teeth
and a second small sun wheel with radially outwardly facing gear
teeth, said first large ring and small sun wheels being rigidly
connected to each other, said second large ring and small sun
wheels being rigidly connected to each other, said first small sun
wheel being coupled to the second large ring wheel by means of one
of said pairs of planetary gear wheels, said first large ring wheel
being coupled to the second small sun wheel by means of the other
of said pairs of planetary gear wheels, said winch further
comprising a reversing gear, and means for rotatably supporting
said reversing gear in said disk, said reversing gear being
arranged for cooperation with one of said sun wheels and one of
said pairs of planetary gear wheels.
14. The drum winch according to claim 1, further comprising a
torque release clutch positioned to couple said jack wheel means
and said disk to each other.
15. The drum winch according to claim 14, wherein said torque
release clutch is positioned to couple said disk and said jack
wheel means to each other through said drum shaft.
16. The drum winch according to claim 1, further comprising a
ratchet wheel coupled to said jack wheel means, and pawl means
arranged for arresting said jack wheel means through said ratchet
wheel against rotation in a direction corresponding to the reverse
rotational direction of said drum.
17. The drum winch according to claim 16, further comprising a
releasable clutch for coupling said jack wheel means and said
ratchet wheel to each other.
18. The drum winch according to claim 17, further comprising means
for supporting said ratchet wheel for axial shifting relative to
said pawl means to permit actuating said releasable clutch, said
supporting means comprising gear box means with a threaded axial
bore, a bearing for taking up axial pressure, threaded position
adjusting means received in said threaded axial bore of said gear
box means for adjustably supporting said axial pressure bearing
means which bear against said ratchet wheel.
19. The drum winch according to claim 16, further comprising a worm
gear means including a worm and a worm gear wheel, means for
rotatably supporting said ratchet wheel inside said worm gear
wheel, and means for journaling said pawl means also inside said
worm gear wheel.
20. The drum winch according to claim 19, wherein said worm is
self-locking relative to said worm gear wheel.
21. The drum winch according to claim 1, further comprising a
ratchet wheel coupled to said disk, and pawl means positioned for
arresting said disk through said ratchet wheel against rotation in
a direction corresponding to the reverse rotational direction of
said drum.
22. The drum winch according to claim 1, wherein said pairs of
planetary gear wheels include respective shafts, and wherein said
ratchet mechanism comprises ratchet wheel and pawl means which are
arranged between one of said planetary gear wheels and the
respective shaft of the pairs of planetary gear wheels.
23. The drum winch according to claim 1, wherein said drive gear
means comprise an outer circumferential collar, said collar
providing a bearing means for said jack wheel means.
24. The drum winch according to claim 23, further comprising gear
box means and roller means for supporting said outer
circumferential collar of said drive gear means in said gear box
means.
25. The drum winch according to claim 1, further comprising a
supporting bearing block, gear box means, and means for securing
said gear box means to said bearing block.
26. The drum winch according to claim 1, wherein said drum shaft
extends axially through the entire drum and the wheel gear means
whereby both ends of said drum shaft are provided with means for
cooperating with a crank handle.
27. The drum winch according to claim 1, further comprising torque
release clutch means positioned to operatively couple said jack
wheel means and said disk to each other, means for axially
supporting said torque release clutch means on the drum shaft,
housing means, and means for axially adjusting the position of said
drum shaft in said housing whereby the braking force of said torque
release clutch is adjustable.
28. The drum winch according to claim 1, further comprising a
releasable braking clutch for coupling the drum to the drive gear
means.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a drum winch. More specifically,
the present drum winch is suitable for use on sailing vessels. The
winch includes a rope drum rotatably supported relative to a drum
shaft. The drum is rotatable by means of a gear drive including a
ratchet mechanism in the same direction independently of the
direction of rotation of the drum shaft which is selectively
rotatable in both directions whereby the drum is rotatable through
the ratchet mechanism at different rotational speeds depending on
the direction of rotation of the drum shaft. The present winch may
further be provided with a releasable brake for the reverse
rotation of the drum.
In order to perform sailing maneuvers with the aid of a drum winch,
the latter must be capable of being driven with at least two
different rotational speeds. This is necessary where the winch is
employed to handle the halyard sheet in order to quickly set or
hoist the sail. On the other hand, it is necessary to pull tight
the sail with a large force against the wind pressure and to
regulate the tightness of the sail under wind pressure. Similarly,
two speeds are required when the winch is employed to handle the
main sheet which may be required to be hauled in quickly as long as
the main sheet is not yet under tensional stress. Thereafter, the
main sheet must be hauled in against increasing tensional forces up
to the maximum tension, whereby the main sheet must also be
controlled or regulated.
Further, a winch used on a sail boat regardless whether it is used
as a halyard winch or a main sheet winch must provide the
possibility of a rapid sheet payout, for example, for taking down
the sails or for rapidly turning or tacking. In this connection, it
is preferable to provide a possibility of braking the sheet being
paid out.
Conventional drum winches for sail boats have drums which are
rotatable in the same direction independently of the direction of
rotation of the crank handle, however, with different rotational
speeds. For this purpose, the driven gear is provided with an
internal spur gear rim which meshes with a reversal gear supported
on a rotatable disk. The reversing or reversal gear meshes
simultaneously with a drive gear attached to the drive shaft. A
locking pawl which is effective in but one direction is arranged
between the disk and the reversing gear. The locking pawl releases
the reversing gear when the driving shaft is rotated in one
direction for rotating the driven gear in a step-down fashion. When
the drive shaft is rotated in the opposite direction, the locking
pawl locks the reversing gear relative to the disk and to the
driven gear whereby a 1:1 rotational speed ratio is accomplished
between the driving shaft and the driven gear.
With the aid of these conventional drum winches, especially if they
are used for regulating the main sheet, particularly in racing, it
is only possible to haul-in the sail by a small amount because the
1:1 speed ratio is insufficient for a rapid haul-in. Thus, it
becomes necessary to haul-in the main sheet by hand while
simultaneously rotating the winch quickly enough for taking up the
slack portion of the sheet whereby the formation of loops must be
avoided because they tend to get tangled. Besides, there is always
the danger that the hand or a finger may get caught between the
main sheet and the winch. During the rapid haul-in it is hardly
possible to temporarily and quickly payout the main sheet again or
to apply a braking action by means of the winch because the drum
cannot follow quickly enough the rapid movement of the sheet.
Besides, at least two persons are required for such a rapid hauling
of the main sheet.
The above considerations apply correspondingly where a conventional
drum winch is employed as a halyard winch and where a sail for
instance a balloon sail is to be set rather rapidly. Here again the
1:1 rotational speed ratio is not sufficient and the setting of the
sail must also be done by hand. If the wind pressure is so large
that a further hauling in of the halyard by hand is not possible,
it would become necessary to use the winch for a further tightening
of the sail provided that the winch can follow up fast enough so
that upon letting go of the halyard, the latter will not be
slackened altogether. Usually it is not possible to follow up with
the drum fast enough and the halyard must be held by hand in the
meantime, whereby it may happen that the pull on the halyard
becomes so large that the halyard runs through the hand causing
substantial burning injuries. Besides, also in this maneuver there
is the danger that the hand or the finger may get caught between
the halyard and the winch. Last but not least, the change over from
the manual handling of the halyard to handling with the aid of the
winch entails a substantial loss of time until the setting of the
sail under wind pressure is completed. Due to this large danger of
injury and due to the cumbersome handling, prior art drum winches
are not suitable for operating the halyard nor the main sheet. On
the other hand, prior art drum winches which provide a large
transmission ratio for the rapid setting of a sail and which
simultaeously have the facility of a large step-down ratio for the
sensitive setting of the sail have the disadvantage that due to
their large space requirements they cannot be suitably installed on
a sailboat due to the limited space conditions. Therefore, drum
winches for performing of sailing maneuvers have not found
widespread application due to the disadvantages outlined above.
OBJECTS OF THE INVENTION
In view of the foregoing, it is the aim of the invention to achieve
the following objects singly or in combination:
to avoid the drawbacks of the prior art, more specifically to
provide a drum winch which is especially suitable for use in
connection with the performing of sailing maneuvers;
to provide a drum winch which shall have simple structural features
and simultaneously require but little space;
to provide a drum winch which is usable for handling the main sheet
as well as the halyard;
to provide a winch which may be easily modified for more than two
rotational speed ratios;
to provide a winch which, though especially suitable for use on a
sailboat, is equally useful in connection with any kind of hoisting
mechanism;
to provide a drum winch having a large step-up ratio in at least
one rotational direction of the drum shaft;
to provide a drum winch having a large step-up ratio in one
direction of rotation of the drum shaft and a large step-down ratio
in the other direction of rotation of the drum shaft, whereby the
other direction of rotation of the drum shaft shall also be capable
of providing a 1:1 transmission; and
to provide a drum winch capable of an especially sensitive
regulation or control in the forward as well as in the reverse
direction of rotation.
SUMMARY OF THE INVENTION
According to one embodiment of the invention there is provided a
drum winch in which the gear drive means comprise a sun and
planetary gear means which include a disk rigidly secured to the
drum shaft and at least two pairs of planetary gears rotatably
supported in said disk as well as a jack wheel or gear. The pairs
of planetary gears mesh with the jack wheel which may be either
locked or which is subject to a braking force, whereby in both
instances, the drum shaft is rotatable relative to the jack wheel.
The jack wheel is coupled to an output drive gear on the drum
through one pair of the planetary gears for a step-up transmission
and through the other pair of planetary gears for a step-down
transmission. The pairs of planetary gears are arranged in such a
manner that for each direction of rotation of the drum shaft they
counteract each other, whereby depending upon the direction of
rotation of the drum shaft, the driving or force transmitting
connection between one pair of the pairs of planetary gears and the
respective output driving gear is interrupted by means of a locking
or ratcheting mechanism. In the just described embodiment the disk
is secured to the drum shaft against rotation whereas the jack
wheel is either locked, for example, against the gear box or
housing or it is subjected to a braking force, the drum shaft being
rotatable relative to the jack wheel. This particular embodiment is
advantageous because it permits a clear and simple structural
arrangement of the gear means. However, it is also quite possible
to secure the jack wheel, instead of the disk, to the drum shaft
against rotation and to lock, instead of the jack wheel, the disk
or to subject the disk to a braking force.
The construction of the drum winch according to the invention
achieves a large step-up transmission in one direction of rotation
of the drum shaft while a large step-down transmission may be
provided in the other direction of rotation of the drum shaft. This
feature has the advantage of a very fast take up of the sheet on
the drum in one direction of rotation of the drum shaft and the
sheet may be drawn tight with a large force in the other direction
of rotation of the drum shaft. Especially, if the disk is driven
and the jack wheel is subjected to a braking force, the required
brake may be effective axially on the jack wheel and the brake may
be provided with a usual brake lining or the brake may be
constructed as a disk brake.
BRIEF FIGURE DESCRIPTION
In order that the invention may be clearly understood, it will now
be described, by way of example, with reference to the accompanying
drawings, wherein:
FIG. 1 is a side view of a drum winch according to the
invention;
FIG. 2 is a longitudinal sectional view through the drum winch
according to FIG. 1;
FIG. 3 illustrates in a somewhat schematic manner and by means of a
perspective, exploded view, the gear means of the present drum
winch;
FIG. 4 is a gear diagram of modified embodiment according to the
invention; and
FIG. 5 is a gear diagram of still another embodiment.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
Referring to FIG. 2, the drum 1 of the present drum winch comprises
a left hand face flange 11 which is rotatably supported on the
housing 2. The housing is divided along the separation plane 202
whereby two housing portions 21 and 22 are formed. The gear means
for the drum 1 comprise sun and planetary gear means. The face
flange 11 of the drum 1 comprises an outer collar 111 which reaches
into the housing 2 whereby the flange is supported on the outer
circumferential surface of the collar by means of rollers 201 in
the housing. A large ring wheel 12 having radially inwardly facing
gear teeth is provided on the inner circumference of the outer
collar 111. The face flange 11 is further provided with an inner
collar 112 arranged concentrically relative to the large ring wheel
12. The inner collar 112 carries a small sun wheel 13 having teeth
facing radially outwardly. A reversing planetary gear 14 meshes
with the large ring wheel 12. The reversing gear 14 is rotatably
supported in the disk 3 of the sun and planetary gearing means.
Further, the reversing planetary gear 14 meshes with the planetary
gear 15 which is also rotatably supported in the disk 3.
The dimensions of the reversing planetary gear wheel 14 and of the
planetary gear wheel 15 are selected in such a manner that the
planetary gear wheel which rotates with its axes about a smaller
circumferential circle does not mesh with the external teeth of the
small sun wheel 13. However, a further planetary gear wheel 16
meshes with the small sun wheel 13. The planetary gear 16 is also
rotatably supported in the disk 3.
A jack wheel 4 is arranged on the side of the disk 3 facing away
from the drum. The supporting jack wheel 4 also comprises a large
ring wheel 41 with an inwardly facing gearing and a small sun wheel
42 arranged concentrically relative to the large ring wheel and
having an external gearing. A planetary gear 43 meshes with the
large ring wheel 41 which is supported on the shaft stump 161 of
the planetary gear 16 so that the planetary gear 43 is secured
against rotation in one direction and rotatable in the opposite
direction of rotation. This locking against rotation in one
direction is accomplished by means of pawls 431 which cooperate
with the ratchet wheel 162 as seen in FIG. 3. The ratchet wheel 162
is secured to the shaft of the planetary gear wheel 16.
Similarly, a planetary gear wheel 44 meshes with the small sun
wheel 42. The planetary gear wheel 44 is supported on the shaft 151
of the planetary gear 15 which meshes with the reversing planetary
gear 14. The planetary gear 44 is rotatable relative to the shaft
151 in one rotational direction whereas pawls 441 prevent the
rotation of the planetary gear 44 in the opposite rotational
direction.
The disk 3 of the sun and planetary gear means is secured against
rotation to the drum shaft 5. Both ends of the drum shaft 5 are
provided with means adapted for cooperation with a crank handle.
For example, each end may be provided with a female hexangonal
socket 501 into which a crank handle may be selectively inserted
either on one side of the drum or on the other side of the
drum.
With the aid of the above described sun and planetary gear means,
it is possible to drive the drum 1 with two rotational speed ratios
in the direction in which the drum shaft 5 and with it the disk 3
are rotated by means of the crank handle. To facilitate the clarity
of the illustration, FIG. 3 shows the gear wheels of the sun and
planetary gear means by their respective pitch circle. Further, the
disk 3 as well as the pawls 431 and 441 and the respective ratchet
wheels 152 and 162 are shown in FIG. 3 in a somewhat symbolized
manner to facilitate the presentation.
Let it be assumed for describing the operation of the sun and
planetary gear means that the jack wheel 4 with its large and small
sun wheels 41 and 42 is stationary. If in this instance the disk 3
is rotated in the counter-clockwise direction as indicated by the
arrow a in FIG. 3, then the shafts of all the planetary gears also
rotate in the counter-clockwise direction about the drum shaft 5.
Thus, the planetary gear 43 which meshes with the stationary large
ring wheel 41 is revolving in the clockwise direction as indicated
by the arrow a1, whereby the pawls 431 of the planetary gear wheel
43 are entrained in the clockwise direction, whereby the ratchet
wheel 162 is also entrained in the clockwise direction as indicated
by the arrow a2 because the pawls 431 are interlocking with the
ratchet wheel 162 in this direction. The ratchet wheel 162 drives
the planetary gear 16 through the shaft 161 also in the clockwise
direction as indicated by the arrow a3. Since the planetary gear
wheel 16 and the small sun wheel 13 mesh together at the face
collar 11 of the drum 1, the small sun wheel 13 and with it the
drum are entrained in a counter-clockwise rotation as indicated by
the arrow a4.
As has been described above with reference to the planetary gear
wheel 43, the planetary gear wheel 44 is also entrained with the
rotation of the disk 3 in the counter-clockwise direction as
indicated by the arrow a. The planetary gear wheel 44 revolves
about the stationary small sun wheel 44 of the jack wheel 4 in such
a manner that it rotates in the counter-clockwise direction as
indicated by the arrow a5. The pawls 441 are also entrained in the
same direction. However, when the planetary gear wheel 44 rotates
in the counter-clockwise direction as mentioned, the pawls ratchet
on the corresponding ratchet wheel 152. Therefore, the ratchet
wheel 152 and the planetary gear wheel 15 which is rigidly
connected to the ratchet wheel 152, are not entrained by the
planetary gear wheel 44. This is in good order because the large
ring wheel 12 and the small sun wheel 13 in the face flange 11 of
the drum 1 rotate at the same angular speed in the
counter-clockwise direction as indicated by the arrow a6, whereby
the reversing planetary gear 14 meshing with the large sun gear 12
also rotates counter-clockwise as indicated by the arrow a7. The
reversing planetary gear 14 meshes with the planetary gear 15.
Therefore, this planetary gear 15 would lock the gear drive unless
the planetary gear 15 is permitted to freely rotate which is
accomplished by the cooperation between the corresponding ratchet
wheel 152 and the respective pawls 441 whereby the planetary gear
15 may rotate in the clockwise direction as indicated by the arrow
a8. Thus, the drum 1 is driven in the counter-clockwise direction
as indicated by the arrow a4 when the drum shaft 5 is rotated in
the counter-clockwise direction as indicated by the arrow a. The
dimensions or the number of teeth of the effectively cooperating
gear wheels will determine the driving speed.
On the other hand, when the drum shaft 5 and with it the disk 3 are
rotated in the clockwise direction as indicated by the arrow b, the
planetary gear wheel 44 revolves about the stationary small sun
wheel 42 of the jack wheel 4 also in the clockwise direction as
indicated by the arrow b1. In this instance, the ratchet wheel 152
and the pawls 441 are effective whereby the planetary gear wheel 15
is also entrained in the clockwise direction as indicated by the
arrow a8. The planetary gear 15 drives now the large sun wheel 12
again in the counterclockwise driection as indicated by the arrow
a6 through the reversing planetary gear 14 which rotates also
counter-clockwise as indicated by the arrow a7. As a result, the
drum 1 now rotates just as in the above described example again in
the counter-direction of the rotation of the drum shaft 5, that is
in the counter-clockwise direction. However, in the second example,
the rotational speed ratio of the drum 1 as compared to the first
direction of the drum shaft 5 is now changed by the dimensions of
the now effective, driving planetary gear wheels. If the drum shaft
5 rotates in the direction of the arrow b in the clockwise
direction the pawls 431 ratchet along the corresponding ratchet
wheel 162. Therefore, the meshing of the planetary gear wheel 43
with the stationary large sun wheel 41 does not entrain the
respective planetary gear wheel 16 whereby the gear wheel 16 may
freely rotate in the direction of the arrow a3 as determined by the
large sun wheel 12 and with the same angular speed under the drive
of the small sun wheel 13.
In view of the above it will be appreciated that the drum 1
according to the invention may be driven with different rotational
speeds depending on the direction of rotation of the drum shaft 5
whereby the drum itself will rotate in the same direction in both
instances, for example, counter-clockwise as shown in FIG. 3.
In connection with the above described operation of an embodiment
it was assumed that the jack wheel 4 is stationary. In the modified
embodiment now to be described, the jack wheel means will not be
stationary. Reference is made of FIG. 2 which illustrates an
embodiment in which the drum may be rotated with different speeds
in the same direction and also with a step-down transmission.
Stated differently, the drum 1 may be rotated with the same angular
speed as the drum shaft 5 provided that the jack wheel means 4 as
well as the face flange 11 of the drum 1 may be rotated with the
same angular speed as the disk 3 which is secured to the drum shaft
5 by tongue and groove means 31. In this embodiment, all planetary
gear wheels remain stationary relative to the jack wheel means 4
and relative to the face flange 11 whereby a 1:1 drive ratio of the
drum 1 by the drum shaft 5 is accomplished in the following
manner.
It is necessary to release the jack wheel means 4 at least for the
direction of rotation of the drum in which the sheet is rolled up
on the drum if it is desired that the jack wheel means 4 may rotate
along with the disk 3 and thus also with the drum 1 for the rolling
up of the sheet. This take up rotation of the drum corresponds in
its direction to the direction of rotation of the large ring wheel
12 as indicated by the arrow a6 in FIG. 3, that is in the
counter-clockwise direction. However, the jack wheel means 4 must
be locked in the opposite direction, that is, in the clockwise
direction in order to produce the counter-force at the jack wheel 4
which is required for the sets of planetary gears when the drum 1
is driven with one of the above described transmissions that is
with a step-up or a step-down transmission. Thus, the jack wheel
means 4 must be arrested in the illustration according to FIG. 3
against a clockwise rotation, further, the jack wheel means 4 must
be released for a counter-clockwise rotation. This may again be
accomplished by means of a ratchet wheel and pawls cooperating with
the ratchet wheel. As may be seen from FIG. 2 the jack wheel means
4 are coupled through a clutch 62 to be described in more detail
below with a ratchet wheel 61 which may best be seen in the
illustration of FIG. 3. The ratchet wheel 61 is released by the
pawls 601 in a rotational direction indicated by the arrow c1. The
jack wheel means 4 are arrested or locked in the opposite
rotational direction as indicated by the arrow c2. According to
FIGS. 2 and 3 the pawls are rotatably supported in a worm wheel 6
which is arranged to be driven by a worm gear 7. If the worm gear 7
is provided with a self-locking feature the worm wheel 6 will
remain stationary as long as the worm gear 7 is not driven. This
driving arrangement through the worm gear 7 will be described in
more detail below. Let it be assumed here that the worm wheel 6 is
stationary whereby the jack wheel means 4 are released for rotation
in a direction indicated by the arrow c1 as seen in FIG. 3. This is
accomplished through the pawls 601 and the ratchet wheels 61 to
which the jack wheel means 4 are coupled by the clutch 62. These
elements arrest the jack wheel means against rotation in the
opposite direction shown by the arrow c2.
As may be seen from FIG. 2 a slipping or torque release clutch 521
is arranged between the drum shaft 5 and the jack wheel means 4.
Another slipping or torque release clutch 511 is effectively
interposed between the drum shaft 5 and the drum 1. These clutches
are effective as long as the pull of the sheet to be wound up on
the drum and thus the torque moment effective on the drum is small.
In order to adjust the frictional force of the cooperating slipping
clutches 521 and 511, the drum shaft 5 is provided in two shaft
portions 51 and 52 which are connected to each other by tongue and
groove means 502 which prevent rotation of one shaft portion
relative to the other but which permit an axial shifting. The shaft
portions or members 51 and 52 may be adjusted in their axial
longitudinal direction relative to each other by means of an
adjusting screw 502 having a head resting against the shaft member
51 at the bottom of the respective female socket 501. The threaded
shank of the screw 503 is screwed into a threaded bore 505 of the
other shaft member 52. Depending upon the extent of adjustment of
the screw 503 the coupling force of the slipping clutches 511 and
521 may be adjusted accordingly, whereby the respective cooperating
elements or members are pressed together with a larger or smaller
frictional force. The adjustment of the screw 503 is secured
against release by means of a spring 504 inserted between the shaft
members 51 and 52. This spring 504 operates simultaneously as a
reset spring since it tends to shift the shaft members 51 and 52
axialy away from each other.
As long as the drum shaft 5 is driven in the take up direction of
rotation of the drum 1 and as long as the slipping clutches 511 and
521 couple the drum 1 and the jack wheel means 4 with the drum
shaft 5, the drum 1 is rotated with the angular velocity of the
drum shaft 5. However, as soon as the pull or tension of the sheet
on the drum 1 becomes so large that the clutches 511 and 521 slip,
a relative rotation is established between the drum 1 and the jack
wheel means 4 which otherwise would be rotated in the clockwise
direction by the pull of the sheet which is prevented by said
slipping and due to the fact that the jack wheel means 4 are
arrested against rotation in this direction. However, due to the
fact that the jack wheel means 4 are arrested for rotation in the
clockwise direction and since the disk 3 is still driven
counter-clockwise along with the drum shaft 5 due to the tongue and
groove means 31 shown in FIG. 2 and as indicated by the arrow a in
FIG. 3, the planetary gear 44 is supported by the small sun wheel
42 whereby it is enabled to drive the drum as described above
through the planetary gear 15, the reversing planetary gear 14 and
the large ring wheel 12 as indicated by the arrow a6.
The structural features so far described permit the following
operation of a drum winch according to the invention. For example,
if the drum winch is employed as a halyard winch, it is possible to
rapidly set the respective sail when the drum shaft 1 is rotated in
the direction of the arrow a as shown in FIG. 3, whereby the
step-up transmission becomes effective and the sail is exposed to
the full wind pressure only after it has been substantially set.
This has the advantage that damages to the sail due to fluttering
are avoided and that the sail is prevented from winding itself
about the mast or the shrouds. However, as soon as the sail is
substantially set and thus provides a large attack surface for the
wind, the tension on the sheet and thus on the drum 1 becomes
larger. At this instance the direction of rotation of the drum
shaft 5 is to be reversed. Thus, prior to the slipping of the
clutches 511 and 521 when a certain sheet tension has been reached,
the drum shaft rotates to drive the disk 3 in the clockwise
direction and with a ratio of 1:1. However, at the instance of
slipping of the clutches 511 and 521 the step-down transmission of
the gearing means becomes effective without any interruptions. The
step-down drive is accomplished through the small sun wheel 42 and
the planetary gears 44, 15 and 14 as well as through the large sun
wheel 12 forming part of the drum flange 11. The sail is now pulled
tight with a large force against the force of the wind due to the
large step down ratio.
The above described drum winch according to the invention may also
be employed in a similar manner for handling the main sheet whereby
it is possible to pull the main sheet quickly tight due to the
large step-up ratio as long as the main sheet is not subject to a
substantial load by the wind through the sail. When the wind
pressure increases, the direction of rotation of the crank handle
may simply be reversed whereby the 1:1 ratio is automatically
established. If the wind pressure increases still more the slipping
clutches 511 and 521 become effective and the further tightening of
the main sheet is accomplished with a large force due to the now
effective step-down ratio.
The drum winch according to the invention is also suitable for
taking the sail down when the winch is used as a halyard winch or
for quickly paying out the main sheet for example when coming about
and tucking maneuvers are to be performed. In order to accomplish
these functions the drum winch as illustrated in FIG. 2 comprises a
clutch which cooperates with the jack wheel means 4 whereby a
reverse rotation of the jack wheel means 4 and thus the rotation of
the drum 1 in the payout direction, that is in the clockwise
direction as illustrated in FIG. 3 is possible.
The just mentioned clutch is the clutch 62 which, as mentioned
above, and as shown in FIG. 2 is arranged between the jack wheel
means 4 and the ratchet wheel 61. The ratchet wheel 61 is supported
within the worm wheel 6 for axial displacement by means of a hand
wheel 63. The hand wheel 63 is adjustable axially in a housing
member 22 by means of a threading 631 for applying a braking action
to the jack wheel means 4 through the clutch 62 or for releasing
the jack wheel means for rotation in the direction indicated by the
arrow c2 in FIG. 3 in which the rotation is otherwise locked by
means of the pawls 601. Thus, the ratchet wheel 61 may be shifted
into or out of its operative position. The hand wheel 63 is axially
supported in the ratchet wheel 61 by means of a ball bearing 632 so
that a relative rotation between the ratchet wheel 61 and the hand
wheel 63 is possible. Depending on the adjustment of the hand wheel
63 and thus upon the pressure applied to the clutch 62 a larger or
smaller braking force may be applied to the jack wheel means 4 with
regard to its rotation in the direction which would otherwise be
locked due to the pawls 601. If desired, the jack wheel means 4 may
be completely released for rotation in the just described
direction. Due to these features according to the invention, the
present drum winch 1 is capable to rotate in the backward
direction, that is, in the clockwise direction according to FIG. 3
in response to tension applied to the drum 1 due to the wind
pressure on the halyard or the main sheet, whereby a braking force
may be applied to such reverse rotation. If the clutch is engaged
again, the drum 1 may be rotated only in the take-up direction in
response to the drive by the drum shaft 5.
Another possibility for releasing the drum rotation in the reverse
direction is illustrated in FIG. 5 wherein a sliding clutch 17 is
interposed between the drum 1 and the output drive wheel 11. The
sliding clutch 17 may be shifted back and forth as indicated by the
double arrow Q for releasing or coupling the drum with the output
drive wheel 11. A clutch between the drum 1 and the output drive
wheel 11 has the advantage that the drum may rotate in the reverse
direction without a corresponding rotation of the crank handle.
As shown in FIG. 2, the worm wheel 6 is provided for operating the
drum 1 additionally to the above described possibilities of
operation, with a very large step-down ratio. The worm wheel 6 is
driven by a drive worm 7 which is in turn operated by means of a
further crank handle not shown or by means of an additional motor 9
shown in FIG. 1, for example an electromotor. This additional very
large step down ratio becomes effective when the worm 7 is driven
in the direction which in turn rotates the worm wheel 6 in the
direction indicated by the arrow c that is in the counter-clockwise
direction. In this direction of rotation the ratchet wheel 61 is
entrained by the pawls 601 whereby the jack wheel means 4 are
likewise entrained if the clutch 62 shown in FIG. 2 is in its
operative position. Accordingly, the jack wheel means 4 rotate in
the direction of the arrow c3 as shown in FIG. 3 whereby the
planetary gear wheel 44 is driven to rotate in the direction of the
arrow b1, whereby the drum 1 is rotated in the counter-clockwise
direction according to arrow a6 with the desired large step-down
ratio, and whereby the drive train runs from the pawls 441 through
the ratchet wheel 154, the planetary gear wheel 15 and the
reversing gear wheel 14. During this type of operation or drive the
disk 3 and thus the drum shaft 5 remain stationary because the
pawls 431 prevent a reverse rotation of the disk 3 in the direction
of the arrow a. A direction of rotation according to arrow a would
mean that the planetary gear wheel 43 is rotated in the direction
of the arrow a1, that is, in the clockwise direction. However, this
is prevented because the large sun wheel 41 rotates, as mentioned
above, in the counter-clockwise direction whereby the planetary
gear wheel 43 drives also in the counter-clockwise direction of
rotation, that is, contrary to the direction of arrow a1.
It is however possible to drive the disk 3 additionally through the
drum shaft 5 whereby the drive through the drum shaft is
superimposed on the drive through the worm 7 and the worm wheel 6.
In this manner it is possible to vary the step-down ratio applied
to the drum 1. By the simultaneous driving through the worm 7 and
through the drum shaft 5 it is possible to provide a continuously
variable step-down ratio or transmission.
By means of the above described position of the pawls 601 as
illustrated in FIG. 3, the drive through the worm 7 and the worm
wheel 6 becomes effective only in one direction of rotation; namely
in the direction of rotation of the worm wheel 6 according to arrow
c as shown in FIG. 3, that is, in the counter-clockwise direction
whereby the ratchet wheel 61 and with it the jack wheel means 4
shown in FIG. 2 are also entrained in the counter-clockwise
direction indicated by the arrow c1 in FIG. 3 provided that the
clutch is engaged.
If the worm 7 remains stationary it prevents by means of its self
locking braking action that the drum 1 would rotate in the reverse
direction in response to a load. Incidentally, the self locking
braking action of the worm 7 could be supplemented by additional
braking means which would be effective on the worm shaft. Further,
a braking action may be provided by driving the worm wheel 7 in the
clockwise direction contrary to the direction indicated by the
arrow c whereby a sensitive backward spooling or run of the drum is
accomplished with the aid of the worm 7. By changing the direction
of rotation of the worm 7, it is thus possible to adjust the
position of the sail attached to the sheet in a sensitive manner
and even against a very large wind pressure. In view of the
foregoing description it will be appreciated that the drum winch
according to the invention may be modified in a plurality of
suitable ways. Among others, the following embodiments are
possible.
a. The sun and planetary gear means comprise an output drive wheel
11, a disk 3, jack wheel means 4 and the sets of planetary gear
means. With the aid of these elements it is possible to provide a
drum winch for a large step-up transmission ratio in one direction
and for a large step-down transmission ratio in the other or
reverse direction of rotation of the drum shaft 5.
b. If in addition to the elements mentioned under (a) above a
slipping or torque reverse clutch is arranged between the jack
wheel means and the disk 3 and a braking action is applied to the
jack wheel means through pawls in one direction, it is possible to
provide a large step-up transmission ratio for one rotational
direction of the drum shaft 5 and to obtain a 1:1 transmission
ratio in the opposite rotational direction of the drum shaft
whereby in said other direction also a large step-down transmission
ratio may be accomplished. Thus, the just mentioned modification or
embodiment of the invention provides three possible rotational
speed ratios.
c. If in addition to the elements mentioned above under (a) or (b)
a worm wheel is provided which is either connected or which may be
coupled to the jack wheel means when the gear train is driven
through the disk 3 or which is connected or may be coupled to the
disk 3 when the gear train is driven through the jack wheel means,
then it is possible to accomplish a very large step-down
transmission ratio by means of which the drum winch may be rotated
in the forward and reverse direction in a sensitive manner.
In view of the foregoing, it will be appreciated that instead of
the disk 3 of the sun and planetary gear train the jack wheel means
4 may be driven with the aid of the drum shaft 5 whereby the
components which in accordance with the described example cooperate
with the jack wheel means 4 would now cooperate correspondingly
with the disk 3.
FIG. 4 illustrates an embodiment of the gear train in which the
jack wheel means 4 are driven and the disk 3 remains stationary.
The representation has been somewhat symbolized for simplicity's
sake. However, the same reference numerals have been employed for
the same elements as shown in FIG. 2. According to FIG. 4 the jack
wheel means 4 which is rigidly connected to the drum shaft 5 simply
comprises a small sun wheel 42 having external gear teeth meshing
with the planetary gear wheels 43 and 44, which are rotatably
supported in the disk 3. These planetary gear wheels 43 and 44 are
connected with the planetary gear wheels 15 and 16 through pawls
441 or 431, whereby a rigid connection is accomplished with regard
to one rotational direction and a rotatable connection is
accomplished with regard to the other rotational direction. The
planetary gear wheel 15 meshes with the large sun wheel 15 having
internal gear teeth whereas the planetary gear wheel 16 meshes with
the small sun wheel 13 having external gear teeth. The large sun
wheel 12 and the small sun wheel 13 are comprised in the drive
output wheel 11 which again is formed in the face flange of the
drum 1.
According to FIG. 4 the disk 3 is rotatably supported on the drum
shaft 5. Further, the disk 3 is coupled with the small sun wheel 42
by means of a slipping or torque release clutch 521. A band brake
32 is arranged to be effective on the outer circumference of the
disk 3. The band brake 32 may be pressed against the disk 3 in the
direction of the arrow "P" or the band brake 32 may be moved off
the disk 3.
By driving the small sun wheel 42 by means of the crank handle 53,
the drum is driven, depending upon the direction of rotation of the
drum shaft, with a step-up ratio or with a step-down ratio. These
ratios are determined by the diameter ratios of the small sun wheel
42 of the jack wheel means and the large ring wheel 12 or small sun
gear 13 of the output drive gear wheel. The diameter of the small
sun wheel 42 of the jack wheel means is smaller than the diameter
of the large ring wheel 12, however, larger than the diameter of
the small sun wheel 13 of the output drive wheel.
Another embodiment comprising a jack wheel means driven by the
crank handle and a stationary support structure is illustrated in
FIG. 5. The basic structural features are the same as those
according to FIG. 2 except that the disk 3 in FIG. 5 is itself
constructed as the worm wheel 6 which is either arrested by the
worm 7 or which is driven by the worm 7. The gear train according
to FIG. 5 does not comprise any slipping clutches as described
above. Therefore the pawls between the disk 3 and the worm wheel 6
may be obviated. Further, as mentioned above, the modification
provides the arrangement of the clutch between the drum 1 and the
output drive wheel 11.
The drum winch according to the invention as shown in the
embodiment according to FIGS. 1 and 2 is secured to a bearing block
8 at the circumference of the housing half 21 whereby a portion of
the flange screws 203 which connect the housing halfs 21 and 22 to
each other at the circumference thereof, serves simultaeously for
securing the drum winch to the bearing block 8. It would also be
possible to support the drum winch on its drum shaft by extending
the drum shaft in one or both directions.
In view of the above, it will be appreciated that for the above
described embodiments it will be sufficient if the brake cooperates
with the jack wheel means or with the disk. Stated differently, it
is not necessary to simultaneously also subject the drum shaft 5 to
a braking action. According to the invention, the rotation of the
drum shaft in both directions always causes the rotation of the
drum in the take-up direction due to the ratchet mechanism
incorporated in the gear train. The ratchet mechanism also assures
that the drum shaft may not rotate automatically in response to the
sheet pull which is effective on the drum.
It should be pointed out that in the embodiment in which the gear
train comprises a sun and planetary gear means an especially large
step-up transmission ratio on the one hand and a step-down
transmission ratio is accomplished on the other hand because the
rotation of the disk is superimposed with the rotation of the pairs
of planetary gear wheels. In this embodiment the gear drive train
is driven by the rotation of the disk and the driving of the pairs
of planetary gear wheels about their shafts is accomplished by the
supporting function of the stationary jack wheel means. On the
other hand the just described embodiment makes it possible to
construct the gear small and compact for a given step-up or
step-down transmission ratio.
The compact structure of the gear means according to the invention
is also facilitated in that the jack wheel means or the power
output drive wheel comprises a small sun wheel and a large ring
wheel rigidly connected to the small sun wheel and in that one pair
of planetary gear wheels is coupled to the large ring wheel whereas
the other pair of planetary gear wheels is coupled to the small sun
wheel. In this embodiment the size of the respective other gear
wheel is reversed, stated differently the size of the power output
drive gear or the size of the jack wheel means is advantageously
selected in such a manner that it is larger than the small sun
wheel but smaller than the large ring wheel.
The power output drive gear as well as the jack wheel means may be
provided with external and/or internal gear teeth. If necessary,
one of the pairs of planetary gear wheels could be arranged so as
not to directly mesh with the jack wheel means and with the power
output drive gear wheel. In this instance a reversing gear wheel
would be interposed in the drive gear train between the jack wheel
means and the power output drive gear wheel, whereby such reversing
gear wheel would be rotatably supported in the above mentioned
disk.
In the embodiment where the jack wheel means or the power output
drive gear wheel comprises a large ring wheel and a small sun wheel
as described above, the large ring wheel may be provided with
internal gear teeth and the small sun wheel may be provided with
external gear teeth. The planetary gear wheels of the pairs of
planetary gears as well as the additional reversing gear wheel if
such is used, may be advantageously arranged in the intermediate
space between the small sun gear and large ring wheel, whereby said
planetary gear wheels mesh with said sun wheels.
An especially small gear wheel drive train which simultaneously
provides a large step-down transmission ratio on the one hand and a
step-up transmission ratio on the other hand may be accomplished
according to the invention in that the jack wheel means as well as
the power output drive gear wheel each comprise a large ring wheel
having internal gear teeth and a small sun wheel having external
gear teeth whereby the ring and sun wheels are rigidly connected to
each other and whereby the small sun wheel of the jack wheel means
is coupled with the large ring wheel of the power output drive gear
wheel through one of the pairs of planetary gear wheels whereas the
large ring wheel of the jack wheel means is coupled to the small
sun wheel of the power output drive gear wheel through the
respective pair of planetary gear wheels. In this instance a
reversing gear wheel is rotatably supported in the disk between one
of the sun wheels and one of the pairs of planetary gears.
Another advantage of the drum winch according to the invention is
seen in that it may be extended by relatively simple means for
including additional step-down or step-up transmission ratios. For
example, the jack wheel means and the disk may be coupled to each
other through a slip or torque release clutch, preferably through
the drum shaft. Such slipping clutch prevents a relative rotation
between the jack wheel means and the disk when the drum shaft
rotates in the direction in which the sheet is spooled onto the
drum as long as the slipping clutch does not slip in response to
the tension effective on the drum. As soon as slipping occurs the
rotational speed of the drum shaft is transmitted to the drum
without any translation, that is, with a 1:1 ratio.
Another advantage of the present drum winch is seen in that it is
possible in a simple manner to assure an instantaneous step-down
ratio in response to the slipping of the torque release clutch
without the need for applying the brake. This feature is
accomplished in that the jack wheel means or the disk that is
respectively the member which is not rigidly connected to drum
shaft, is coupled with a ratchet wheel which is arrested in the
direction of rotation which corresponds to the reverse rotation of
the drum, said arresting being accomplished by means of pawls. In
this embodiment the forward direction of rotation of the drum is
released so that the jack wheel means or the disk may be driven in
the forward direction of the drum through the slipping clutch
without any relative rotation between these two members. As soon as
the pull or tension of the sheet exceeds the braking force of the
slipping clutch upon continued rotation of the drum shaft, the
pawls engage with the ratchet wheel whereby the gear is
automatically switched to the step-down transmission ratio. These
features are considered to be an independent invention.
Advantageously the ratchet wheel and the jack wheel means or the
disk are coupled to each other by means of a releasable clutch.
This feature has the advantage that after releasing of the clutch
the rotation of the drum in the reverse direction is released which
prior to such release was blocked by the ratchet wheel whereby the
sheet may be paid out from the drum. Depending on the adjustment of
the clutch the clutch may simultaneously act as a brake.
Another advantageous construction is achieved, especially where a
ratchet wheel cooperates with the jack wheel means when the ratchet
wheel is axially shiftable relative to the pawls for actuating the
clutch, whereby the ratchet wheel is actually supported by a
pressure bearing which in turn is adjustable by means of a hand
wheel supported in a thread in the housing of the gear train means.
Thus, the drum shaft and the hand wheel may be operated
simultaneously or alternatively whereby a sensitive adjustment of
the sail may be accomplished.
In many instances it is advantageous if the clutch for releasing
the reverse rotation of the drum is effectively interposed between
the drum and the power output drive wheel. Particularly in this
embodiment the rotation of the crank handle along with the
reversely rotating drum is prevented. Thus, the crank handle may
always remain attached to the drive shaft and it is not necessary
to remove it for avoiding the danger of injury when the drum
rotates in the reverse direction.
Another advantage of the invention is seen in that the present drum
winch may be modified for an especially large step-down
transmission ratio for driving the drum. This has the advantage
that the sail may be strongly tightened even against a very large
wind pressure. Such additional large step down transmission ratio
is accomplished according to the invention in that the ratchet
wheel is rotatably supported within a worm gear wheel in which
there are installed the pawls and which is driven by the worm 7 as
described above. The brake for arresting the pawls in the
rotational direction in which they are to lock the ratchet wheel
may in this embodiment be applied either to the worm gear wheel 6
or to the shaft of the worm. The worm could be driven either by an
additional crank handle or advantageously by means of an electric
drive motor. In the latter embodiment it is possible to provide a
remote control for several drum winches and the sails controlled by
such winches. The brake required for braking the worm gear wheel
may then be accomplished by a suitable drive means, the rotation of
which is prevented in the standstill.
A separate large step-down transmission ratio by means of the worm
and the worm gear wheel in combination with the other drive
possibilities of the drum by means of the gear drive train is
especially advantageous because the simultaneous or alternate
driving of the drum shaft and/or of the worm provides for a
sensitive regulation of the sail adjustment. The sail may be pulled
tight or slackened depending on the direction of the drive rotation
of the worm. In this embodiment additional continuous speed ratio
variations for the drum are accomplished when the drum shaft and
the worm are driven simultaneously. Here again, it is considered
that this arrangement and the effect of the worm wheel constitute a
separate invention within the framework of the present
application.
In order to arrest the worm wheel when the worm is stationary, it
is suggested according to the invention to provide the worm with a
self-locking feature relative to the worm wheel gear.
In view of the foregoing, it will be seen that the drum winch
according to the invention in its simplest embodiment provides a
step-up transmission and a step-down transmission which become
effective depending upon the direction of rotation of the drive
crank handle. If in addition a slipping clutch is installed between
the disk and the jack wheel means, a 1:1 rotational speed ratio is
also accomplished. Where, for example, the crank handle drives the
disk, and the jack wheel means are arrested only in the direction
of rotation corresponding to the reverse direction of rotation of
the drum, the sail may be pulled tight quickly, for example, when
the winch is used for the main sheet, by rotating the crank handle
quickly in said one direction of rotation whereby said step-up
ratio becomes effective. As soon as the direction of rotation is
reversed, a 1:1 transmission ratio is established whereby the sail
may be pulled tight further to an extent which is determined by the
slipping strength of the slipping clutch which will slip when the
wind pressure exceeds such strength. As soon as the wind pressure
exceeds said value, the slipping clutch begins to slip whereby
automatically the step-down ratio becomes effective while the
direction of rotation of the crank handle remains the same. As a
result, the sail may be pulled tight against a large wind pressure
due to said step down ratio.
If in addition a worm gear drive is installed for the ratchet wheel
as described above, then the sail may be regulated in a sensitive
manner in both directions and against large wind pressure.
Although the invention has been described with reference to
specific example embodiments, it is to be understood, that it is
intended to cover all modifications and equivalents within the
scope of the appended claims.
* * * * *