U.S. patent number 3,667,418 [Application Number 05/024,416] was granted by the patent office on 1972-06-06 for marine towing device.
This patent grant is currently assigned to Aktien-Gesellschaft "Weser". Invention is credited to Hans-Georg Janssen.
United States Patent |
3,667,418 |
Janssen |
June 6, 1972 |
MARINE TOWING DEVICE
Abstract
A marine towing device has support means which is to be mounted
on a marine vessel. A hook is pivotably mounted in a frame and
interposed between and connected with both the support means, and
the hook is an elastically yieldable unit which yields elastically
to a predetermined maximum extent if tensile forces develop between
the support means and the hook, as when the latter is engaged with
an element to be towed.
Inventors: |
Janssen; Hans-Georg
(Bremerhaven, DT) |
Assignee: |
Aktien-Gesellschaft "Weser"
(Bremen, DT)
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Family
ID: |
6600631 |
Appl.
No.: |
05/024,416 |
Filed: |
March 13, 1970 |
Foreign Application Priority Data
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Mar 15, 1969 [DT] |
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G 69 10 623 |
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Current U.S.
Class: |
114/249; 280/486;
267/138 |
Current CPC
Class: |
B63B
21/56 (20130101) |
Current International
Class: |
B63B
21/56 (20060101); B63b 021/00 () |
Field of
Search: |
;114/235,235A
;280/486,487 ;267/138,141,71,72 ;188/268 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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605,959 |
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Feb 1926 |
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FR |
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609,200 |
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Sep 1960 |
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IT |
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Primary Examiner: Blix; Trygve M.
Claims
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended
1. A marine towing device, comprising support means adapted for
mounting on a marine vessel; engaging means, including a slip hook
arrangement adapted for engagement with and release of an element
to be towed, at the will of an operator; and an intermediate device
between and cooperating with said support means and engaging means,
including an elongated tubular housing connected with one of said
means, and a one-piece elongated elastomeric element accommodated
axially and with slight radial play in said housing and operatively
connected with the other of said means whereby, in response to
development of a selected tensile stress between said engaging and
supporting means and acting longitudinally of said housing, said
elastomeric element will undergo axial compression and concomitant
radial expansion into progressively increasing frictional
engagement with an internal surface of said housing, so as to
provide a progressive energy-absorption effect.
2. A towing device as defined in claim 1, said support means
comprising a frame and a hook pivotably mounted in said frame; and
wherein said intermediate device is connected with said frame.
3. A towing device as defined in claim 1, said elastomeric element
being an elastically axially compressible sleeve of synthetic
plastic material surrounding said rod portion within the confines
of said tubular housing.
4. A towing device as defined in claim 3, said sleeve having an
exterior surface and an outer diameter and undergoing radially
outward expansion in response to axial compression; and wherein
said tubular housing has an interior surface adapter to be engaged
by said exterior surface and an inner diameter which exceeds that
outer diameter by an amount determined in dependence upon the
maximum desired axial compression of said sleeve.
5. A towing device as defined in claim 1, said support means
including a universal joint for affording said intermediate device
freedom of movement with reference to a marine vessel on which said
support means is mounted.
6. A towing device as defined in claim 1, said intermediate device
further comprising a rod-portion partly accommodated in said
housing and being connected with said other means, said elastomeric
element cooperating with said rod portion and housing and being
compressible in response to relative sliding movement thereof in
axially opposite directions.
7. A marine towing device, comprising: support means adapted for
mounting on a marine vessel; engaging means, including a slip hook
adapted for engagement with an element to be towed; and an
intermediate device between and cooperating with said support means
and engaging means, including an elongated tubular housing
connected with one of said means and having a closed end and an
open end which faces and is connected with said support means, an
elongated elastomeric element accommodated coaxially and with
slight radial play in said housing and operatively connected with
the other of said means whereby, in response to development of a
selected tensile stress between said means and acting
longitudinally of said housing, said elastomeric element will
undergo axial compression and concomitant radial expansion into
engagement with an inner circumferential surface of said housing, a
rod-shaped portion having a bifurcated end which embraces said
housing and extends from said closed end toward said open end, said
elastomeric element being resiliently compressible and accommodated
in said housing, and a contact portion with said bifurcated end and
adapted to bear upon and compress said elastomeric element in
response to relative movement of said rod-shaped portion axially of
said housing and away from said open end.
8. A towing device as defined in claim 7, said housing being
provided with a pair of axially extending diametrally opposite
slots, and said contact portion comprising a pin extending through
said slots and having opposite terminal sections connected with
said bifurcated end.
9. A towing device as defined in claim 8, said contact portion
further comprising a plate member secured to said pin within the
confines of said tubular housing and oriented in a plane transverse
to the axis of said housing.
10. A towing device as defined in claim 7, said elastomeric element
being a resiliently compressible member of synthetic plastic
material.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a marine towing device,
and more particularly to a marine towing device utilizing a
so-called slip hook.
It is known to mount such towing devices on marine vessels in such
a manner that the frame of the hook--in which the hook itself is
pivotably journalled--is directly and articulately connected with
the marine vessel. For this purpose the portions of the vessel,
usually a portion of the superstructure thereof, are specially
reinforced to be able to withstand the stresses which develop when
the hook is engaged with an element to be towed. Usually a cable or
rope is interposed between the element and the hook, being
connected to the element to be towed and being engaged by the hook.
The problem with these prior art constructions resides in the fact
that momentary tensile stresses--such as for instance develop if
the rope engaged with the hook suddenly changes from a slack to a
taut condition--are directly transmitted to the towing vessel. This
frequently leads to breakage of the cable rope, and may have even
more severe consequences, namely disturbances in the operation of
the marine vessel or even a significant damage to the vessel
itself, for instance the superstructure on which the towing device
is mounted.
It is known to attempt to correct this by interposing in the towing
rope--or constituting the latter of--sections of natural fiber, for
instance Manila hemp. This material is capable of yielding to a
certain extent and thus to provide a relief for the problem in
question. However, ropes made of such material must have rather
large cross-sections in order to withstand the high stresses placed
upon them, stresses which in case of momentary development of the
stress cannot in practice be controlled. In actual use it is
frequently found that Manila hemp rope of the necessary
strength--that is cross-section--is frequently not available when
needed, particularly when the towing rope is changed over from one
towing vessel to another so that there may not have been any
previous possibility of making preparations.
In any case, no means has heretofore become known in this art which
is capable of avoiding the aforementioned problem and which in all
operational circumstances will guarantee a significant reduction in
the stresses transmitted to the marine vessel to which the towing
device is secured.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to overcome
the aforementioned disadvantages.
More particularly it is an object of the present invention to
provide a marine towing device which is not possessed of these
disadvantages.
A further object of the invention is to provide such a marine
towing device which avoids the sudden transmission of tensile
stresses to the marine vessel on which the device is carried, but
which does not adversely affect the towing stresses which can be
placed upon the device.
In pursuance of the above objects and others which will become
apparent hereafter, one feature of the invention resides, in a
marine towing device, in the combination which briefly stated
comprises support means adapted for mounting on a marine vessel,
engaging means adapted for engagement with an element to be towed,
and intermediate means interposed between and cooperating with the
support means and the engaging means. According to the invention
the intermediate means is elastically yieldable to a predetermine
maximum extent in response to development of a selected tensile
stress between the support means and engaging means.
The construction of the intermediate means in accordance with the
present invention is such that it is capable of transmitting towing
stresses up to a selected value without reacting, but will react to
towing stresses in excess of this value, particularly to sudden
tensile stresses which develop.
In accordance with one embodiment of the invention the intermediate
means comprises a rod pivotably connected with the frame of the
engaging means or hook unit, and a sleeve surrounding the rod and
in which the latter is axially slidably guided, with resilient
means--such as a spring or the like--being axially compressible in
response to movement between the rod and the tubular member or
sleeve in a sense withdrawing the two from one another. It has been
found that the elastically yieldable means may particularly
advantageously be in form of a sleeve of synthetic plastic material
which is elastically deformable in axial direction and surrounds
the rod, engaging with its opposite axial ends the tubular member
and the rod, respectively. Suitable synthetic plastics for this
purpose are already well known and commercially available under
various names such as Adacell, Vulkollan or the like foamed
polyurethan.
With this construction it is readily possible to determine the
extent to which the rod and sleeve can move axially with reference
to one another in a sense moving away from each other, that is the
extent to which the unit can elastically yield, by making the outer
diameter of the sleeve smaller than the inner diameter of the
tubular member to such an extent that the outer circumferential
surface of the sleeve will engage the inner circumferential surface
of the tubular member--whereupon the elastic deformation
ceases--when the desired elastic deformation has been reached. It
will be appreciated that in response to axial deformation of the
sleeve the same will be radially outwardly deformed so that the
contact between the outer surface and the inner surface of the
tubular member takes place.
Advantageously the support means by way of which the towing device
is connected with a marine vessel comprises a universal joint to
afford free movement of the device with reference to the
vessel.
The novel features which are considered as characteristic for the
invention are set forth in particular in the appended claims. The
invention itself, however, both as to its construction and its
method of operation, together with additional objects and
advantages thereof, will be best understood from the following
description of specific embodiments when read in connection with
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a somewhat diagrammatic fragmentary axial section through
a device according to the present invention;
FIG. 2 is a section taken in a plane extending at right angles to
the plane of the section in FIG. 1; and
FIG. 3 is a view similar to FIG. 1, but on an enlarged scale and in
a more fragmentary illustration, of a further embodiment of the
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Discussing firstly the embodiment illustrated in FIGS. 1 and 2 it
will be seen that reference numeral 1 identifies a hook, which in
conventional manner, is pivotably mounted in a frame 2 for turning
movement about a substantially horizontal axis. In its operating
position the hook 1 is maintained by means of a non-illustrated
slip device which, when it is desired to slip or release the rope
or cable engaged by the hook 1, can be actuated or "slipped" by the
lever 3. The elements 1, 2 and 3 are entirely conventional and well
known to those skilled in the art; for this reason they have been
illustrated in FIG. 1 and particularly in FIG. 2 in broken lines.
The illustration is to be understood as being merely an aid to a
better understanding of the position of the novel intermediate
means with reference to the elements 1, 2 and 3 which together
constitute the engaging means of the towing device.
In accordance with the present invention I provide an intermediate
means E which is located between and connected with the frame 2 and
the support means 4 which in turn is secured to a portion of a
marine vessel 5. The portion of the vessel 5 may be a part of the
superstructure thereof; its particular identity is immaterial for
purposes of the invention.
The element E comprises, as illustrated, a rod 6 which is
articulately connected with the frame 2, as shown at 6a, and a
tubular member 7 which surrounds a portion of the rod 6 with the
latter extending through an opening in the end wall 9 which closes
the end of the tubular member 7. Surrounding the rod 6 within the
confines of the tubular member 7 is a sleeve 8 of synthetic plastic
material which is axially resiliently compressible and which is
confined between and bears upon the end wall 9 of the tubular
member 7 and a shoulder 10 provided at the free end of the rod 6
adjacent the nut 6b. The presence of the sleeve 8, which latter
constitutes elastically yieldable means for the element E, also
serves to provide guidance for the rod 6 during axial movement
between the same and the sleeve 7. Reference numeral 11 identifies
a universal joint which is a part of the support means 4 and which
affords the element E freedom of movement with reference to the
vessel 5.
Coming now to the embodiment illustrated in FIG. 3 it will be seen
that this differs from that of FIGS. 1 and 2. In particular, the
embodiment of FIG. 3 utilizes for the intermediate element a
tubular member 7a which has one closed end and one open end, with
the latter facing towards the vessel on which the device is
mounted, and which vessel must be thought of as being located at
the right of the device in FIG. 3. Reference numeral 11 identifies
a connecting member which is secured to the vessel and anchored--as
by means of a bolt 14 traversing openings adjacent the free end of
the tubular member 7a and the member 11--with the tubular member
7a. Accommodated within the tubular member 7a is resilient means in
form of an elastically compressible body or member 15 of suitable
synthetic plastic material. The rod member 6 of FIGS. 1 and 2 has
here been replaced with the member 6a which may also be thought of
as a rod member but which has a bifurcated end portion surrounding
the tubular member 7a from the closed end thereof and being axially
slidable with reference to the tubular member 7a. The latter is
provided inwardly of its open end with a pair of diametrally
opposite slots 13 which are elongated in the axial direction of the
tubular member 7a, and a pin, bolt or analogous member 12 extends
through these slots 13 and is anchored in the bifurcated end
portion of the member 6a. Movement of the member 6a axially of the
member 7a in the direction towards the left-hand side of the FIG.
3, movement of the member 7a towards the right-hand side of FIG. 3,
or simultaneous movement of the member 6a and 7a in their
respective directions, causes the pin or analogous member 12 to
bear against the member 15 and thereby compress the same axially,
obtaining the desired resilient spring action. In the illustrated
embodiment of FIG. 3, however, I have provided a small disc or
plate 16 which is suitably secured to the pin 12--as by
welding--within the confines of the tubular member 7a, and which is
the element actually contacting and effecting axial compression of
the member 15. This provides for more even compressing action.
The length of the slots 13 defines the limits of compression and
sudden shock-like stresses are absorbed by the member 15 when they
exceed a certain limit. Of course, if the pin 12 moves into
abutment with the left-hand ends (with reference to FIG. 3) of the
slots 13, then there is a direct transmission of stresses from the
frame 2 to the member 11 and thereby to the vessel, and this will
ordinarily take place only if the stresses build up gradually
rather than momentarily and suddenly.
It will be appreciated that the device according to the present
invention affords greater safety and ease of operation, eliminates
economic losses and dangers due to breakage of the rope or cable
used for towing, and eliminates economic losses and dangers to
personnel resulting from the sudden transmission of stresses in
shock-like manner to the vehicle--that is marine vessel--on which
the device is mounted.
It will be understood that each of the elements described above, or
two or more together, may also find a useful application in other
types of constructions differing from the types described
above.
While the invention has been illustrated and described as embodied
in a marine towing device, it is not intended to be limited to the
details shown, since various modifications and structural changes
may be made without departing in any way from the spirit of the
present invention.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can by applying current
knowledge readily adapt it for various applications without
omitting features that, from the standpoint of prior art, fairly
constitute essential characteristics of the generic or specific
aspects of this invention and, therefore, such adaptations should
and are intended to be comprehended within the meaning and range of
equivalence of the following claims.
* * * * *