Note: Descriptions are shown in the official language in which they were submitted.
Winch
The invention is concerned with a winch device
and in particular with a method for controlling the
operation of the winch. In the present patent
application, as an example off winch device in
accordance with the application will be use a winch
device used in forestry for harvesting of timber, the
designation winch hying used for the said winch device
in the following.
It is characteristic of such prior art winches
as include a working rope and a control rope or cord for
controlling the operation of the winch that the control
rope must be tensioned or pulled outwards from the winch
when the winch is supposed to pull the working rope
into the winch. These winches known at present may be
divided into two groups in respect of their principle
; of operation:
A simple winch started by tensioning the
control Hope. The reel of the working rope can revolve
freely unless the control rope has been tensioned. In
order to couple such a winch so that it pulls, the
control rope must be tensioned so that the operating
connection between the working-rope reel and the power
source of the winch is connected, whereupon the winch
keeps pulling the working rope into the winch until
the counter-force caused by the working rope exceeds
the power transmitted by the operating connection. In
a winch of this type, the operating connection may be
produced, e.g., by means of a friction coupling con-
trolled by means of the control rope, or by means of
a corresponding drive gear. Thus, such a winch operates
in accordance with the on/off principle, i.e. the
hoistincJ is started my tensioning the control rope and
stopped by slackening the control rope. If controlling
of the pulling force of the winch is desired, that
control must be performed by regulating tile compression
I
force of the friction coupling, i.e. the tensioning
of the control rope. In this winch type, the control
rope moves little (e.g., 0.5 m) for the purpose of
starting and controlling the hoisting, and even that
in a direction opposite to the working rope, i.e.,
when the working rope is supposed to be wound into thy
winch, the control rope must be kept tensioned by
pulling it outwards from the winch and, correspondingly,
in order to stop the hoisting, the control rope must
be allowed to be slackened towards the winch.
As an example of the winch described above J
the winch it accordance with the Finnish Announcement
Publication No. 50,405 can be mentioned. The hydraulic
winches in use at present also operate by means of the
same control principle. In these winches, the control
of the valve opening and closing, respectively, the
supply of oil to the hydraulic motor has been accom-
polished so that the valve is opened when the control
lever of the valve is tensioned, e.g., against a spring
force, and that, correspondingly, the valve is closed
by the effect of the said spring force when the control
lever is released. If the operation a the control
valve is supposed to be performed more remote from the
winch, the operation of the said valve may be con-
trolled, eye., by means of a control cord attached lathe control lever.
In the Finnish Patent 59,378, a winch is
described whose operation is affected, besides by the
tensioning of the control cord, also by its ~ovemerlt.
Such a winch possesses certain advantac3es, described
in the said patent, aver the simpler winch described
above. In that winch, e.g., the revolving angle of
the working-rope reel can be controlled more accurately.
The winch is as such suitable, e.g., for loadLrlg a
forest tractor if the hoisting distances are short, it
in the case of long hoisting distances, the same problems
are encountered as with the winch mentioned above.
it
In this winch as well, the control rope moves
in a direction opposite Jo the working rope, i.e., when
the control rope is being pulled out of the winch, the
winch pulls the working rope into the winch, and the
other way round. Thus, both the working rope and the
control rope, or at least one of them, are always
outside the winch.
It is a problem of both ox the winch types
mentioned above that, when the hoisting distance is
long, the operator must handle a long control rope in -
his hands and/ when he approaches the winch with the
log, he must all the time reel out the control rope by
hand, i.e. it must be kept tensioned. If the hoisting
distance is, e.g., 40 metros and if the length of the
control cord is the same, after the operator has hoisted
the lo to the proximity of the winch, e.g. in accordance
with the Finnish Patent 50,405, he has a skein of 40
metros of control rope in his hands. Thus, in practice,
out of the above reason, the length of the control rope
is limited to about ten metros, but that results in a
new problem. If the length of the control rope is less
than the hoisting distance, the operator must first
attach the hoisting claws to the log and thereupon
return to the control rope to start hoisting. However,
in practice it often happens that when the working rope
is tensioned, the hoisting claws slip off the log, and
the operator must return to the log, attach the hoisting
claws, go back to the control rope, etc.
In order to overcome these difficulties, a
reeling device carried on -the back is at present used
as an aid to some extent, which said device reels the
slack control rope by means of spring force into the
device. The reeling device is full of rope when the
operator is alongside the winch, but it is emptied
when he walks off the winch. The quantity of rope
that can be reeled into the device is, however, rota-
lively limitec1, and in practice the extreme limit: of
I
its operation is often reached, at which time it can no
longer deliver control rope. The reeling device is of
some help, but the following deficiencies and drawbacks
still remain:
The reeling device acco~nodates only about
30 to 40 metros of control rope, and if the log to be
hoisted is more distant, the operator must take the
reeling device off his back and, after he has attached
the hoisting claws to the lo, he must return to the
reeling device in order to start hoisting. When a - -
winch is used, e.g., for harvesting wood in the cast
of thinning out of the forest, the hoisting distances
are often longer than the distance of operation ox the
reeling device.
ennui the operator hoists the log and, at the
same time approaches the winch together with the log,
he must keep the control rope tensioned all the time,
which means that he must reel the rope towards himself
at least by the distance that he moves, and even more in
the case of the winch types in which the control rope is
placed on a reel revolving in a direction opposite to
the working-rope reel.
The operator's walking along with the log to
be hoisted may cause various dangerous situations, e.g.
when the operator happens to fall down during hoisting.
Thereat the control rope is most likely to be slackened,
whereat, in the prior-art winch constructions, the
consequence it that the operating connection pulling the
working-~ope reel, such as the friction coupling, is
opened. For example, in a steep upwardly slanting
hillside, this results in the situation that the log
may rush down the hill against the operator unless the
winch includes a particular safety device to prevent
such a situation. Such a safety device is also required
by the law in certain countries.
It is an object of the present invention to
avoid the above drawbacks and to provide such a methot3
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_ 5 27370-
for controlling a winch and such a winch by means of which the
working becomes easier, faster, safer, and more convenient. In
view of achieving the effects stated above, -the method in accord-
ante with the invention is mainly characterized in that the
winding-in of the working-rope reel is produced by allowing the
control rope to ye pulled in relative to the working-rope and
in that the speed of winding-in of the working rope is restricted
or the winding-in of the working-rope is stopped respectively,
by restricting the winding-in of the control rope relative to
the winding-in of the working-rope. The winch invented for
accomplishing the method is characterized in that the winch con-
sits of a stationary hollow shaft supported on an appropriate
frame construction, of a working-rope reel mounted at one end
of the hollow shaft, revolving freely on the said shaft but having
a restricted axial movement, of a connecting shaft passing through
the hollow shaft and projecting out of both of its ends, the said
connecting shaft being installed as freely revolving relative
the hollow shaft, of a control-rope reel installed on the portion
owe the connecting shaft projecting out of the end opposite to
the working-rope reel, which control-rope reel. is arranged as
substantially freely revolving on the connecting shalt and has
a restricted possibility of axial movement relative the said
shaft, of a secondary drive wheel installed on the hollow shaft
between the working-rope reel and the con~rol-rope reel alongside
the workin~-rope reel as freely revolving but a locked in respect
of axle moment of a friction face between the workincJ-rope
reel and the secondary drive wheel, of a rotational wedge member
~2~57~
- pa - 27370-5
between the locked end of the connecting shaft passing through
the control-rope reel and the control-rope reel, of a rotational
wedge member between the opposite Lockwood end of the connecting
shaft and -the working-rope reel, of members for forcing the
control-rope reel to revolve with a limited force relative the
connecting shaft in the direction expanding the rotational wedge
member that shifts the control-rope reel axially, as well as of
members for forcing the connecting shaft to revolve along with
the control reel.
The winch in accordance with the invention will be
described in detail with reference to the attached drawing,
without in any way restricting the winch in accordance with the
invention to the construction in accordance with -the said drawing,
because the winch in accordance with the invention can be
accomplished in many different ways. In the drawing,
Figure 1 is an axonometric view of a winch in accordance
with the invention, partly in section,
Figure 2 shows the rotational wedge member of the winch
in accordance with the invention as viewed in the axial direction,
Figure 3 shows the wedge member of Fig. 2 as viewed
in a direction perpendicular to the axial direction, and
Figure 4 is a sectional view of a part of the wedge
member along line A-A in Fig. 2.
The winch device shown in Fig. 1 consists of a
stationary hollow shaft 13 attached to an appropriate frame
construction 19 as well as of a wor~ing-rope reel 7 and a control-
rope reel 33, mounted on the said shaft 13 as freely revolving
I
~22~ a
- 5b - 27370-5
and having a limited axial movement, as well as of members, mounted
on the said hollow shaft 13, for producing the driving power and
for controlling the operation of the working-rope reel and the
control rope reel relative -to each other.
One of the applications of use of the winch is operation
as a timber hoist in forest conditions, in which case the winch
is constructed so that it can
~,~
~2g~
be mounted to the three-point fastening gear of a
tractor, and in such a case it receives its operating
power from the power take-off of the tractor. The
reeling power for the winch is transmitted by means of
appropriate equipment (not shown) to a chain 47 and,
by means of the chain, further to the drive or chain
wheel 16. In the embodiment shown, the same equipment
also transmits the operating power to the control
equipment of the winch by the intermediate of a chain
46 and a cogwheel 25. - -
At one end of the hollow shaft 13, theworking-rope reel 7 of the winch is installed as freely
revolving on bearings 10, the working rope 48 that pulls
or lifts the load being wound onto the said reel 7, and,
correspondingly, unwound for the purpose of hoisting a
new load. The journalling of the working-rope reel 7
has been accomplished so that the workiny-rope reel can
move substantially freely but restrictedly, in a way to
be described below, on the shaft 13.
A connecting shaft 1 is journal led inside the
hollow shaft 13 as passing through it and projecting out
of both of its ends. The connecting sheaf t 1 is con-
centric with the hollow shaft 13, and it is journal led
as freely revolving relative the hollow shaft 13. At
the end of the connecting shaft 1 that projects out of
the end of the hollow shaft 13 next to the working-rope
reel 7, a locking nut 2 or equivalent has been fastened
as the outermost component. Between this locking nut
and the working-rope reel 7, the first rotational wedge
member 4,5,6 is installed, whose purpose will be
explail1ed later. At the opposite end of the connecting
shaft 1, a locking nut 36 or equivalent has been fixed
correspondingly and, inwards from the said nut 36, a
rotational wedge member 31~32J35 corresponding to that
mentioned above the purpose ox this second member
being likewise explained later. Inwards from the
rotational wedge member, on the Projecting portion of
I
the connecting shaft 1, the control-rope reel 33 is
mounted further, being freely revolving but having a
restricted axial movement.
The said chain wheel 16 is mounted on the
hollow shaft 13 as freely revolving, but as axially
immobile relative the hollow shaft. The said chain
wheel 16 is mounted alongside the working rope reel 7,
at the side facing the control-rope reel 33, so that
the working-rope reel 7 can reach contact with the
friction face 15 on *he chain wheel 16 within the limits -
of its axial movement. In the embodiment shown, the
second said chain wheel 25 is mounted in connection
with the control-rope reel 33, at the side facing the
working-rope reel 7, so that the control-rope reel 33
can reach contact, by means of the members attached to
the said reel 33, with the friction face 29 on the
chain wheel 25 within the scope of its axial movement.
The second said chain wheel 25 is also journal led on
the hollow shaft 13 as freely revolving but as locked
in respect of axial movement.
The said members attached to the working-rope
reel 33, which act jointly with the friction face 29 on
the chain wheel 25, consist of drag members 26 fixed
onto the control-rope reel 33 as well as of a clutch
disc 30 attached to the connecting shaft 1 non notably
but with a restricted movement in the axial direction.
In addition to the members described above,
which are essential for the operation of the device,
the device in accordance with the invention also
includes a locking member 40, functioning as a safety
device, which in certain operating situations locks
the control-rope reel 33 against revolving in the
direction of inward winding and, at the same time,
causes stropping of the working rope reel. The con-
struction and the operation of the safety c1evi~ebe descried below.
The operation of the winch can be described
by means of the following example. It is assumed as a
starting situation that the drive chains 46 and 47
receive operating power whereat the chain wheels 25 and
16 revolve in the direction indicated by the arrows,
i.e. downwards at tile front side in Fig. 1. The working
rope has been pulled out, and there is a load at its
end. The control rope 43 is also in the pulled-out
position, substantially at an equal distance as come
10 pared with the working rope 43. - -
In this situation, if the control rope has
been tensioned with a certain force so that the locking
40 is open and the winding-in of the control-rope reel
is prevented by the tensioning force of the control
lo rope, the rotational wedges 4 and 32 are in their
narrowest positions in the axial direction, whereat the
friction coupling 15 between the chain wheel 16 and the
workiny-rope reel 7 is open and, likewise, the coupling
between the clutch disc 30 and the friction coupling 29
is open. On the contrary, the control-rope reel 33
is in rubbing contact with the friction face on the
chain wheel 25 by means of its ragging members 26.
Under these circumstances, the said dragging members
cause a tendency in the control-rope reel to revolve
I along with the chair wheel 25, i.e. in the direction
winding the control rope inwards. The operator of
the winch annuls this tendency by keeping the control
rope tensioned in the way mentioned above
In this situation, if no wishes that the
workiny~rope reel 7 winds the working rope 48 inwards,
he slackens the control rope 43 a little. 'Irrupt the
control-rope reel 33 is trend being pulled by the
drown members 26, in the direction of winding-in,
i.e. the corltrol-rope reel 33 performs a little
35 bit of a revolution relative the collecting shaft: 1.
This revolving movement, on the other hind rockets in
the circumstance that the rotational wedge member 32
expands in the axial direction and pushes the control-
rope reel 33 in the axial direction towards the chain
wheel 25 and the clutch disc 30. If the control-rope
reel is allowed to revolve more in the same direction
by slackening the control rope, a situation it reached
in which the control-rope feel presses the clutch disc
30 against the friction face 29 on the chain wheel 25,
whereat the connecting shaft 1 tends to revolve along
with the control-rope reel 33.
On the other hand, a revolution of the con- - -
netting shaft 1 in the direction of inward winding
causes an expansion of the rotational wedge member 4 of
the working-rope reel 7 in the axial direction, whereat
this rotational wedge pushes the working-rope reel 7
towards the friction face 15 of the chain wheel 16.
When the connecting shaft 1 revolves sufficiently in
the direction of inward winding, the friction coupling
15 is coupled and the working-rope reel starts
revolving. If the winch operator, in this situation,
delivers control rope to the winch without braking the
inward winding of the rope at all, i.e. if the control
rope is allowed to be wound in completely freely at its
maximum speed of inward winding, the chain wheel 16,
the working-rope reel 7, the connecting shaft 1, the
chain wheel 25, the clutch disc 30, and the control-rope
reel 33 revolve as a unit of the same speed, and the
winch pulls the load towards the winch device. Both the
working rope 48 and the control rope 43 are then wound
in the same direction, i.e. inwards, and, if the
3Q diameters of the reels have been selected correctly,
substantially at the same speed r which is an essential
advantage of the invention as compared with the prior-
art corresponding winches.
If the winch operator wishes to reduce the
speed of winding in of the working rope or to stop the
hoisting, he retards the winding-in of the control
rope 43 to such an extent that eye control-rope reel 33
1226571
1 0
remains a little angular movement after, relative the
connecting shaft 1. Thereat, the rotational wedge
member 32 is returned in the axial direction correspond
dingy in its narrowing direction, whereat the come
press ion pressure between the control rope reel 33,
the clutch disc 30, and the flaxen face 29 is reduced.
Thereby the clutch disc can slip yin the trailing
direction relative the chain wheel 25, whereat the con-
netting shaft 1 is no longer rotated at the same speed
as in the earlier situation relative the working-rope
reel 7, which also results in a slackening of the
rotational wedge 4 A As a result of this, the friction
coupling 15 starts slipping, whereat the winding-in of
the working-rope reel 7 is retarded by the effect of
the burdening load. When the movement is stopped
completely by means of the control rope 43, the said
friction couplings are opened to such an extent that
the burdening force of the load and the force developed
by the clutch 15 fully overrule each other, whereat
the winding is stopped, but the load cannot flow
backwards either.
In the operating model described above, it
has been assumed, or the sake of simplicity, that in
full-power winding-in the friction couplings are
completely closed, i.e. non-slipping, but in practice,
expressly in the winch application of the invention,
it may be preferable that the speeds of revolution of
the chain wheels 16 and 25 are selected high enough
so that the friction couplings always slip to some
extent.
After the load has been hoisted to the
proximity of the winch, the operator detaches the
toad and starts pulling the working rope 48 and the
control rope 43 out of the winch. Thereat the control
US rope must be pulled ahead of the jerking rope, whereat
the friction couplings causing the winding-in are opened
in the way described above. The only force opposed to
~26~i7~
the pulling out of the ropes remains the friction caused
by the dragging members 26 between the control-rope
reel 33 and the chain wheel 25, which friction is
necessary for the starting again of the winding. In
this situation as well, it is possible to reduce the
burdening force generated by the dragging members 26
essentially by means of a particular feature of the in-
mention without any harm to the winding function ox the
winch. According to this particular feature, the winch
has two sorts of dragging members 26. Some of them are
long and resilient so that they extend onto the friction
face 29 even when the control-rope reel is most distant
from the chain wheel 25. On the other hand, others are
shorter and more rigid than those mentioned above,
whereat they do not reach contact with the friction
face 29 until after the control rope reel 33 has been
shifted a certain distance towards the chain wheel 25.
In this way, the resistance to revolving of the control-
rope reel in the direction of winding-out can ye made
low, and its winding-in can be made to start softly.
On the other hand, the rigid dragging members guarantee,
at a later stage of starting of the winding process,
strict following of the control reel along with the
chair wheel 25, and consequently reliable connecting
of the drive.
Another particular feature of the invention
comes out ho means of the attached figures I, 3 and 4.
According to this particular feature, the wedge faces
of the rotational wedge members have been shaped so
that they have variable pitch When the rotational
wedge starts operating out of its retracted position,
i.e. when the components 4 in Fig. 3 tend to revolve
relative each other, the pitch of the wedge faces 50
is steeply rising, whereat, at the final end of the
operation of the rotational wedge members, the pitch
of the wedge fact becomes more gently rising. Til~reby
it is achieved that a slight movement at the initial
AL
12
stage of the winding process between the control-rope
reel 33 and the connecting shaft 1 as well as between
the connecting shaft and the working-rope reel 7, ..
respectively, causes a strong axial expansion of the
rotational wedge members, whereat any play movements
slowing down the operation of the device can be elm-
noted efficiently and the winding can be made to start
rapidly. On the other hand, when the winding takes place
at full power, the gently rising wedge faces guarantee
a strong axial compression effect of the rotational - -
wedge members and thereby guarantee non-slipping of the
friction couplings. Correspondingly, by means of
this arrangement, the winch can be made to be released
efficiently when the ropes are being pulled out for the
next hoisting cycle.
For the purpose of describing the construction
and operation of the safety lock included in the winch,
we shall come back to Fig. 1. The safety lock consists
of a shaft fixed to the frame 19 of the winch, on which
shaft a lever member 39 has been arranged as pivot able
so that it is provided with two projecting cams. One
of the cams. is provided with a pulley 42, over which
the guide rope 43 is pulled. The opposite cam 40 is
designed as a grasping member, which is arranged so
as to engage in a tooth recess 34 provided at the end
face of the guide-rope reel. The pivoting of the
lever 39 in the direction engaging in the tooth recess
34 is caused by a spring member 44.
The objective of the said safety mender is to
watch the tensioning of-the control rope 43 and to cause
stopping of the hoisting if the tensioning of the control
rope becomes lower than the value determined by the
spring 44. Such a situation may occur, e.g., if the
person operating tile winch falls Dwight during the
hoisting in which case the control rope may become
slack. Thereat, if the winch did not have the said
safety member, there would be a risk that the luckily or
Lo
13
any other load resting on the working rope bruises the
winch operator who fell down in the path of the load,
for a slack control rope would mean a full-power hoist
command for the winch.
On the contrary, by the effect of the safety
device, when the tensioning of the control rope 43
becomes lower than the value set by meals of the spring
44, the cam 40 grasps the recess 34. Thereby the
wlnding-in of the control-rope reel stops, which again
results therein that the connecting shaft 1 and the -
working-rope reel reach the control-xope reel locked in
position. This again results therein that the rota-
tonal wedge members become retracted and that the
friction coupling acting upon the working-rope reel is
opened. If, in this situation, the load happened to be,
e.g., on a steep upwardly inclined hillside, it Waldo
tend to pull the working rope outwards, it the
working-rope reel 7 would tend to be wound open as
pulled by the load. However, as the control rope reel
is locked in its position by the effect of the
rotating force produced by the chain wheel 25 and by
the dragging members as well as by the effect of the
locking effect produced by the cam 44, a relative move-
mint is produced between the reels 7 and 33, which
movement results in an axial reopening of the rota-
tonal wedge members and in a coupling of the friction
clutches so that the working-rope reel I having been
stopped remains slipping on its friction clutch 15.
Should it happen at this stage further that
the winch loses its drive power, in the winch in
accordance with the invention t precautions can be
taken for that situation 50 that the chain wheel 16,
which transmits the drive power to the working-rope
reel 7, is provided with a catch device which, at
the hoisting stage, permits revolving of tune chain
wheel in the direction of winding--l.n only. The said
catch device is, however, not entirely indispensable,
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14
for in a situation in which the drive power of the
winch it lost, reasonable security is obtained for the
winch against winding back by making the catch toothing
34 on the control-rope reel 33 such that it grasps in
both directions, whereat, when the control rope becomes
slack, the control rope reel 33 is prevented from
revolving in any of the directions. Thereby, when the
working-rope reel 7 attempts to be wound out, the
winch is wedged, owing to the opening of the rotational
wedge members, and becomes a rigid unit, which is
locked against windiny-out by the intermediate of the
lever member 39 against the frame 19 of the winch.
In order to restart the winding in a situation
in which the winch receives drive power, it is enough
that the control rope 43 is tensioned against the
effect of the spring 44 to such an extent that the cam
40 comes out of the recess 34, whereby the co~trol-rope
reel can again revolve and the hoisting starts again
By means of the winch construction described
above, which is described as one embodiment of the
method in accordance with the patent claim, the express
advantage has been obtained, in view of the operation,
that both the working rope and the control rope are
always wound on the same direction, whereat, by means
of correct choice of equipment, the speeds of winding
can additionally be made substantially equal. Thus,
the operator of the winch does not have to wind the
control rope towards himself as he walks towards the
winch when the hoisting makes progress. It is enough
that he keeps the end of the control rope in his hand
and walks towards the winch at his own speed. The
winch itself takes care of the remaining of the control
rope tensioned, i.e. winds it in at the walking speed
of the operator, whereat, correspondingly/ owing to
the control functions of the winch, the winding in of
the working rope takes place substantially at the same
speed at which the operator approaches the winch.
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Besides thy fully mechanical exemplifying
embodiment described above the control method in
accordance with the invention may also be accomplished
by means of winches of hydraulic or electrical
operation.
Moreover, the winch in accordance with the
invention may also be accomplished as a dual construe-
lion in which the rope reels revolve in opposite
directions, in which ease the winch gives a good embody-
mint for a funicular drive.
