U.S. patent application number 10/567458 was filed with the patent office on 2006-10-12 for retraining device for a cable.
This patent application is currently assigned to Novatug B.V.. Invention is credited to Markus Van Der Laan.
Application Number | 20060226278 10/567458 |
Document ID | / |
Family ID | 34214840 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060226278 |
Kind Code |
A1 |
Van Der Laan; Markus |
October 12, 2006 |
Retraining device for a cable
Abstract
Retaining device for a cable This consists of a rotary drum (2)
around which at least two cable windings are made, retaining and
paying out being possible by means of a motor (10) that drives the
drum. According to the present invention the axis (12) of rotation
for the drive is offset with respect to the axis of the drum, so
that in a certain position the axis (12) of rotation is essentially
coincident with the casing face of the drum engaging on the
cable.
Inventors: |
Van Der Laan; Markus;
(Oegstgeest, NL) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
Novatug B.V.
P.O. Box 23384
Rotterdam
NL
NL-3001 KJ
|
Family ID: |
34214840 |
Appl. No.: |
10/567458 |
Filed: |
August 10, 2004 |
PCT Filed: |
August 10, 2004 |
PCT NO: |
PCT/NL04/00561 |
371 Date: |
May 17, 2006 |
Current U.S.
Class: |
242/603 |
Current CPC
Class: |
B66D 1/30 20130101 |
Class at
Publication: |
242/603 |
International
Class: |
B65H 75/14 20060101
B65H075/14 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 11, 2003 |
NL |
1024079 |
Claims
1. Winch system comprising a retaining device for a cable,
comprising a drum for containing at least two windings of the cable
on the casing face thereof, said drum being mounted on bearings
such that it can rotate, wherein the distance from the casing face
of said drum to the axis of rotation of said bearings varies around
the periphery of said drum, said winch system comprises a cable
storage having a winding/unwinding drum separate from said
retaining device.
2. Winch system according to claim 1, wherein at least one location
on the periphery of the casing face is essentially coincident with
the axis of rotation of said bearing.
3. Winch system according to claim 1, wherein said casing face is
circular cylindrical.
4. Winch system according to claim 1, wherein the drum is driven by
a motor.
5. Winch system according to claim 1, wherein grooves for
accommodating the cable have been made in said casing face.
6. Winch system according to claim 1, wherein the surface of the
casing face is provided with means to obtain more friction between
the casing face and the cable.
7. Winch system according to claim 1, wherein said drum is designed
to accommodate a stock of cable.
8. Winch system according to claim 1 comprising braking means.
9. Tug having a winch device with a winch system comprising a
retaining device for a cable, comprising a drum for containing at
least two windings of the cable on the casing face thereof, said
drum being mounted on bearing such that it can rotate, wherein the
distance from the casing face of said drum to the axis of rotation
of said bearings varies around the periphery of said drum, said
winch system comprising a cable storage having a winding/unwinding
drum separate from said retaining device, wherein the cable release
point/pick-up point with respect to said boat can be adjusted over
360.degree. in an essentially horizontal plane.
10. Tug according to claim 9, wherein the axis of said drum in the
unloaded state is essentially vertical.
Description
[0001] The present invention relates to a retaining device for a
cable, comprising a drum for containing at least two windings of
the cable on the casing face thereof, said drum being mounted on
bearings such that it can rotate. A retaining device of this type
is generally known in the state of the art. With a rotating drum a
cable can be pulled tight or paid out again. Such drums are used in
particular in shipping, such as on tugs or other vessels.
[0002] When the cable is under tension and when paying out thereof,
high `pinching forces` with respect to underlying cable are
produced in the cable wound around the drum, which forces reduce
the strength and life of the cable.
[0003] In view of the relatively large diameter of the drum (and
thus long stretch of outgoing cable) high forces are needed to hold
the cable under full load and also to pull the cable. This means
that the brake/locking system (and to a lesser extent the drive
motor) for the drum have to be of corresponding heavy construction
so as to be able to apply a high force to the cable, which
translates to a high torque via the diameter of the drum. The
diameter of the drum is determined by the diameter of the cable.
Cables may be subjected to only limited bending. If bending is too
great there is an appreciable loss of strength and damage to the
cables occurs in the long term.
[0004] The aim of the present invention is to provide a retaining
device for a cable with which it is possible to apply a high
retaining force, that is to say a high torque, to the drum using a
relatively small brake/locking system and a simple drum. On the
other hand, it must be ensured that sufficient movement of the
cable can be achieved with the drum.
[0005] This aim is achieved with the retaining device described
above in that the distance from the casing face of said drum to the
axis of rotation of said bearings varies around the periphery of
said drum.
[0006] According to the present invention the centre of the drum is
no longer coincident with the axis of rotation of the drive
thereof. As a result the casing face of the drum with which the
cable comes into contact will be alternately closer to and further
away from the axis of rotation. The highest retaining force can be
exerted on the cable at the point in time when the axis of rotation
is closest to the casing face. This force is lowest at the point in
time when the casing face is furthest away from the axis of
rotation. What can be achieved by this eccentric arrangement is, on
the one hand, that optimum retaining force is provided by
appropriate choice of the point where the cable is engaged and, on
the other hand, it is guaranteed that there is adequate
winding/unwinding speed. In this way a relatively small
brake/locking system (that can comprise the drive motor) can
suffice. Restriction of the size of the brake/locking system is
essentially dependent on the reduction in the distance from the
axis of rotation to the casing face. More particular the axis of
rotation is within the shell circumference of the drum but deviates
from the center of said drum.
[0007] In a particular embodiment it is found that the capacity of
the brake/locking system can be reduced by more than a factor of
ten. As a result it is possible to start from a completely
modified, highly simplified construction.
[0008] If the distance from the casing face to the axis of rotation
of the drum is particularly small there will be no or hardly any
moment when pulling. Paying out of the cable then has to be
achieved by positive driving of the drum by turning it using a
motor. As a result, the distance after which the movement continues
by itself also increases. Positive driving can, however, also be
implemented by means of a mechanism or lever.
[0009] In all cases, the drum will be able to reach appreciable
speeds of rotation when paying out. In principle, imbalance is
produced as a result of the eccentric construction. According to
the present invention, this imbalance is removed by providing
balancing, for example by fitting additional weights. By fitting
these weights as far as possible at the outer periphery, the moment
of inertia is also increased.
[0010] A significant advantage of this rotary construction is that
when paying out the cable moves together with the supporting
surface under high load (no slip) and produces no wear on the two
surfaces.
[0011] According to an advantageous embodiment of the invention, at
least one location on the periphery of the casing face is
essentially coincident with the axis of rotation of said bearings.
Essentially must be understood to mean that there can be some
distance because of the diameter of the drive shaft.
[0012] According to an advantageous embodiment of the invention,
preferably when used on tugs with towing installations that can
rotate 360.degree. in the horizontal plane, the axis of rotation
will preferably be essentially vertical. As a result it is possible
to achieve a low installation height, in contrast to conventional
winches with horizontal axes of rotation, while nevertheless the
cable is subjected to slight bending (large drum diameter).
[0013] According to a further advantageous embodiment the casing
face is cylindrical and more particularly circular cylindrical. In
order to increase the retaining force on the cable, grooves are
made on (a part of) the casing face to accommodate the cable. When
such grooves are used, the retaining force can be increased to a
higher percentage of the tensile strength of the cable. Up to 95%
of the breaking strength of the non-bent cable has been found
possible when an optimum diameter of the drum is chosen.
[0014] According to a further advantageous embodiment the surface
of the casing face is made rougher or provided with other materials
with a higher coefficient of friction to make the friction between
the casing face and the cable greater. As a result, all force is
transmitted per winding and fewer windings on the drum can
suffice.
[0015] According to a further advantageous embodiment the drum
consists of an eccentric part and of a centric part, a guide system
being able to guide the cable from the one part to the other. With
this arrangement it is possible to guide the cable on the centric
part when hauling in and paying out and to direct the cable around
the eccentric part only when holding. The separation between these
parts can be constructed as a partitioning board provided with an
opening 10-25% of the circumference in size.
[0016] According to a further advantageous embodiment the drum is
not only constructed as a retaining device for the cable but also
as a store. In this case the part for storage of the cable would
usually be positioned centrically with respect to the axis of
rotation. In general, a separate part of the drum that is above or
below the retaining device will be used for this purpose.
[0017] The invention also relates to a winch system where storage
of the cable is separated from the retaining device. This storage
is some distance away and can be effected in a wide variety of
ways, including storage on a single drum, storage around a system
of several drums, stored in storage system, etc.
[0018] The invention will be explained in more detail below with
reference to an illustrative embodiment shown in the drawing. In
the drawing:
[0019] FIG. 1 shows, diagrammatically, the retaining device
according to the invention in combination with a separate cable
store; and
[0020] FIG. 2 shows a bottom view of the retaining device according
to the invention; and
[0021] FIG. 3 shows, diagrammatically, the retaining device
according to another variant of the invention in combination with a
separate cable store.
[0022] In FIG. 1 the retaining device according to the invention is
indicated by 1. This consists of a drum 2 that is driven by a motor
10 and brake/locking system 20 and 21. The bearing for the
construction is indicated by 9 but it will be understood that any
other bearing can be used. Drum 2 is of circular cylindrical
construction with an axis 11. The circular cylindrical storage drum
14 with an axis 12 is fixed on top of drum 2. In the illustrative
embodiment shown the axis of the storage drum 14 is coincident with
axis 12. However, it is also possible to position this
eccentrically like drum 2.
[0023] The axis of rotation of the drive shaft 8 of motor 10 is
indicated by 12. It can be seen from FIGS. 1 and 2 that the axes of
rotation 11 and 12 are offset with respect to one another. On the
casing face 13, the drum 2 is provided with peripheral grooves 3
for accommodating two windings of cable 4.
[0024] 5 indicates a cable guide that can be moved up and down in
the direction of arrow 6 in order to guide the cable into the
groove in the correct manner or to guide the cable from the drum 2
to the storage drum 14 and vice versa. A rim 20 on which, highly
diagrammatically, a brake block 21 can engage extends downwards
from the bottom part of drum 2.
[0025] In FIG. 2 the drum is shown in the position in which the
highest tensile force can be delivered. It can be seen that the
axis 12 is essentially coincident with the casing face 13, so that
the maximum pulling or paying out force can be exerted on the cable
4 with the aid of a motor 10.
[0026] Another variant of the invention with a separate storage
drum 7 is shown in FIG. 3. The cable 4 first runs round the
circular cylindrical drum 2 with axis 11, then a number of layers
around the circular cylindrical part with axis 12 and then
continues to the separate storage drum 7. In the illustrative
embodiment shown the axis of the top drum is coincident with axis
12. However, it is also possible to arrange for this part to be
coincident with axis 11; the cable then runs a number of windings
around an eccentric drum and then continues to the separate storage
drum 7. Moreover, it is possible to move motor 10 for driving
storage drum 7. Drum 2 is driven by driving storage drum 7.
[0027] Clear variants will be apparent to those skilled in the art
on reading the above; these are in particular dependent on the use
of the retaining device. Such variants fall within the scope of the
appended claims.
* * * * *