Field of the invention
[0001] The present invention belongs to the field of constructional details in forest winches,
more precisely to the field of guiding mechanisms for precise leading of a rope during
its winding and/or unwinding onto a drum of a winch.
Technical problem
[0002] The technical problem is constructional solution of a guiding arm for a wire rope,
which will enable controlled winding of a rope onto a drum in a winch. The rope must
be wound so that coils on the drum will be placed one next to another (side by side)
without any crossings or overlaps. During use a winch almost never stands on a horizontal
surface, but is rather inclined to one side with regard to the longitudinal direction
or backwards/forwards with regard to the transverse direction of the winch. Weight
of the guiding arm has a lever arm with regard to the rotation axis, therefore the
arm can spin-stagger, which results in momentum of gravity force around the rotation
axis. The force in the rope is not always sufficient to overcome the momentum, therefore
the arm does not move along the longitudinal axis of the drum, which results in the
rope being unequally wound along the whole width of the drum, so that it is wound
in a pile or one coil on top of the others. The task and objective of the invention
is to eliminate the fundamental problem of winding a rope onto a drum.
State of the art
[0003] Slovene patent no. 24108 discloses a solution »Forestry winch with controlled winding of traction rope and
protection thereof overload«. Rope winding in this winch is performed in a controlled
manner, which means that each disposable windings of said cable on the surface of
a winding drum should be arranged side by side relatively to each other and without
any transpositioning or overlapping, and that each overloading of said towing cable
and other components of a driving assembly due to towing of too heavy load should
be excluded. To this aim, the winch is furnished-with-a-directing assembly, which
is arranged between an upper pulley block and said winding drum and is freely rotatable
or least pivotable at certain angle around the vertical geometric axis, wherein said
winch moreover includes a dynamometer suitable for measuring of tensioning force within
said towing cable, so that also the winding drum can be controlled depending on each
measured loading of the towing cable.
[0004] Utility design
DE202014105161U1 discloses a directing assembly, which is mounted on the vertical axis and can freely
turn left and right along the drum axis. This system works flawlessly if the winch
operates on a flat-horizontal ground. If the winch is during its operation inclined
left or right or backwards or forwards or in any possible combination of these inclinations,
the weight of the assembly inclines the intermediate assembly between the outlet part
with the rope and the drum in the direction of the dynamic force to one side or becomes
stuck for a specified period of time in one place. Consequently the rope starts to
wind in a pile, which is not desired.
Description of the invention
[0005] The essence of a mechanism of a guiding arm for a wire rope in a winch is in that
the rope or a chain together with two sheaves forms a loop, which connects on one
side the guiding arm and on the other side a weight. The guiding arm and the weight
are due to the loop connection always at the same distance, while their position with
regard to the drum depends on the position of the rope on the drum, which is independent
of the terrain on which the winch stands. The guiding arm is rotatably mounted into
the winch housing or the drum housing perpendicularly to the drum axis and oscillates
along the longitudinal axis of the drum, wherein the wire rope is guided with directing
discs towards an outlet opening at a part of the winch, where the wire rope has its
ending intended for attachment of a load intended for towing.
[0006] The mechanism of the guiding arm for a winch wire rope will be described in further
detail by reference to the accompanying figures, which show:
- Figure 1
- scheme of the guiding arm and the drum - longitudinal plane,
- Figure 2
- the mechanism of the guiding arm,
- Figure 3a
- the winch on a flat surface - transverse plane,
- Figure 3b
- the winch inclined around its longitudinal axis to the left - transverse plane,
- Figure 4a
- the guiding arm when the winch is inclined forwards with regard to its transverse
axis,
- Figure 4b
- the guiding arm when the winch is inclined backwards with regard to its transverse
axis.
[0007] The role of the guiding arm 1 installed on the winch is to guide the wire rope 2
along the longitudinal axis of the drum 3 during winding/unwinding of the rope 2 onto
the drum 3, so that the rope 2 is wound onto the drum 3 in layers in the shape of
a helix. The guiding arm 1 is with a bearing 10 rotatably mounted into the winch housing
or into the drum housing perpendicularly to the drum axis and oscillates along the
longitudinal axis of the drum 3. The guiding arm 1 is moved left-right along the longitudinal
axis of the drum 3 by the wire rope 2, if the latter is sufficiently strained. The
wire rope 2 is led from the drum 3 with a sheave 4 on the guiding arm 1 and directing
discs 8 through an outlet opening on the rear side of the winch, where the said wire
rope 2 has its ending enabling attachment of a load. The sheave 4 on the guiding arm
1 can be driven with a hydraulic motor, which enables unwinding the rope from the
drum 3. In order to ensure that the rope 2 does not slide on the sheave 4 during unwinding,
the rope 2 is pushed against a groove in the sheave 4 with one or more pressing cylinders
5, which are connected into a chain with connecting elements 6. The pressure intensity
of pressing cylinders 5 on the rope 2 is adjusted with a spring 7.
[0008] The bearing 10 is installed in a supporting console 11, the bearing 10 being rigidly
mounted on the guiding arm 1. Onto the supporting console 11 a guide 12 is mounted,
to which a weight 13 is attached. The weight 13 is composed from one or more parts
of any shape. The weight 13 has an accessory 13a for attachment to the guide 12 and
enables movement in the transverse direction in relation to the winch or in the longitudinal
direction in relation to the drum axis. A connecting rope or chain 15 connects the
weight 13 and the guiding arm 1 with a left sheave 14a and a right sheave 14b, so
that the weight 13 moves in the opposite transverse direction in relation to the guiding
arm 1. This prevents movement of the arm 1 to the side due to inclining of the winch
as shown in figure 3b. Consequently the guiding arm 1 of the rope 2 remains at the
same position during use of the winch regardless of the winch being inclined to one
or the other side due to the configuration of the terrain. The rope or chain 15 may
have any shape and may be made of any material and can be any other possible connecting
element intended for transmission of movement via sheaves 14a and 14b, preferably
a strap.
[0009] Figure 3a shows the position of the winch on a horizontal surface, while figure 3b
shows the winch in case when the winch is inclined around its longitudinal axis to
the left side. In figure 3b a dynamic component Fu is directed into the left side,
while the weight of the weight 13 causes a tension force Fr in the rope 15, which
via the sheave 14b pulls the guiding arm to the right. If the weight 13 has a sufficient
mass, then the weight 13 and the guiding arm 1, connected by the rope 15, are in balance
or are still as Fu is equal to Fr. Friction in guides of the weight 13 can be adjusted
with additional screws on an accessory for placing the weight 13 onto the guide 12.
This additionally stabilizes the mechanism so that eventual thrusts of burdening onto
the winch in the transverse direction do not cause unneeded oscillation of the guiding
arm 1 or the weight 13.
[0010] If the winch is inclined forwards as shown in figure 4b, the guiding arm 1 always
falls to the side and is in an unstable position. The weight 13 on the guide 12, which
is with the rope 15 connected to the guiding arm 1, disables or holds the guiding
arm 1 at the wire's current position on the drum 3. When the winch is inclined backwards
as shown in figure 4a, the guiding arm might return towards the middle of the drum
3. This can be prevented with the present invention in the way that the ends of the
guiding arm 1 are connected with the wire 15, which is mounted between sheaves 14a
and 14b and weight 13 on the other side, the said weight 13 moves along the guide
12 in the opposite transverse direction with regard to the guiding arm 1. The guiding
arm 1 is rotatably mounted in the winch housing, wherein the wire rope 2 is guided
via directing discs 8 towards an outlet opening at a part of the winch, where the
wire rope has its ending intended for attachment of a load intended for towing.
[0011] The present invention enables controlled winding of a rope onto a drum, when a winch
is used on different uneven terrains.
1. A mechanism of a guiding arm for a winch wire rope characterized in that a rope or a chain together with two sheaves forms a loop, which connects on one side
the guiding arm and on the other side a weight; that the guiding arm and the weight
are due to the loop connection always at the same distance, while their position with
regard to the drum depends on the position of the rope on the drum; that the guiding
arm is rotatably mounted into the winch housing or the drum housing perpendicularly
to the drum axis and oscillates along the longitudinal axis of the drum, wherein the
wire rope is guided with directing discs towards an outlet opening at a part of the
winch, where the wire rope has its ending intended for attachment of a load intended
for towing.
2. The mechanism of the guiding arm for a winch wire rope according to claim 1, characterized in that the ends of the guiding arm (1) are connected with a rope or a chain (15), which
is mounted between sheaves (14a and 14b) and a weight (13) on the other side, which
together with its accessory (13a) moves along a guide (12) in the opposite transverse
direction in relation to the guiding arm (1); that the guiding arm (1) is rotatably
mounted in the winch housing or in the drum (3) housing perpendicularly to the drum
(3) axis and oscillates along the longitudinal axis of the drum (3), wherein the wire
rope (2) is guided with directing discs (8) towards an outlet opening on the part
of the winch where the wire rope (2) has its ending for attachment of a load; that
in a supporting console (11) a bearing (10) is installed, which is rigidly attached
to the guiding arm (1); that on the supporting console (11) the guide (12) is installed,
to which the weight (13) is attached; that the weight (13) has the accessory (13a)
for mounting onto the guide (12) and enables movement in the transverse direction
in relation to the winch or in the longitudinal direction in relation to the axis
of the drum (3); that the friction in guides of the weight (13) can be adjusted with
additional screws on the accessory (13a) for mounting the weight (13) onto the guide
(12).
3. The mechanism of the guiding arm for a winch wire rope according to claim 2, characterized in that the weight (13) consists of one or more parts of any shape.
4. The mechanism of the guiding arm for a winch wire rope according to claims 2 and 3,
characterized in that the rope or the chain (15) may have any shape and may be made of any material; that
the rope or the chain (15) can be any other possible connecting element intended for
transmission of movement via sheaves (14a and 14b), preferably a strap.
5. The mechanism of the guiding arm for a winch wire rope according to any of the preceding
claims, characterized in that the rope (2) is pushed against a groove in a sheave (4) with one or more pressing
cylinders (5), which are connected into a chain with connecting elements (6); that
the pressure intensity of the pressing cylinders (5) on the rope (2) is adjusted with
a spring (7).
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description