U.S. patent application number 12/013744 was filed with the patent office on 2008-05-08 for tug barge lightering connection system.
Invention is credited to Clare J. KUHLMAN.
Application Number | 20080105185 12/013744 |
Document ID | / |
Family ID | 39358645 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080105185 |
Kind Code |
A1 |
KUHLMAN; Clare J. |
May 8, 2008 |
TUG BARGE LIGHTERING CONNECTION SYSTEM
Abstract
A lightering connection system is provided for coupling a tug
boat to a barge, where the connection permits relative vertical
movement between the tug and barge while maintaining horizontal
movement control between the vessels. The tug boat has port and
starboard retractable rams having coupler heads which engage the
barge along inboard port and starboard vertical receiver channels.
The coupler heads and vertical receiver channels are provided with
waveform surfaces to permit interlocking engagement between the tug
boat and barge. The waveform surfaces also permit smooth relative
movement of the surfaces as the ram disengages in performing the
lightering operation. The coupler heads and vertical channel
receivers have a mating angular construction to maintain horizontal
movement control between the tug and barge during the lightering
operation.
Inventors: |
KUHLMAN; Clare J.; (Platte
Woods, MO) |
Correspondence
Address: |
SPENCER, FANE, BRITT & BROWNE
1000 WALNUT STREET
SUITE 1400
KANSAS CITY
MO
64106-2140
US
|
Family ID: |
39358645 |
Appl. No.: |
12/013744 |
Filed: |
January 14, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11345792 |
Feb 2, 2006 |
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12013744 |
Jan 14, 2008 |
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Current U.S.
Class: |
114/249 |
Current CPC
Class: |
B63B 35/70 20130101 |
Class at
Publication: |
114/249 |
International
Class: |
B63B 21/58 20060101
B63B021/58 |
Claims
1. A coupler and receiver assembly for connecting a pusher vessel
within a stern notch of a barge, the assembly comprising: a pair of
rams provided on lateral sides of the pusher vessel, a coupler head
attached to each of the rams, receiver channels for receiving each
coupler head provided on the barge, each receiver channel
comprising first and second generally opposed sidewalls, each of
the coupler heads comprising lateral edges, at least one of the
lateral edges of each coupler head having a primary waveform
surface with a plurality of rounded, non-angular projections, at
least one of the first and second sidewalls of each of the receiver
channels having similar secondary waveform surfaces adapted to mate
with the lateral edge of the coupler heads having the primary
waveform surface.
2. The coupler and receiver assembly of claim 1 in which the pusher
vessel is adapted for engagement with the barge when the primary
waveform surfaces of the lateral edges of the coupler heads mate
with the secondary waveform surfaces of the receiver channels such
that crests of a wave of a first waveform surface lie completely
within troughs of an opposing second waveform surface.
3. The coupler and receiver assembly of claim 1 in which the
sidewalls of the receiver channels are angularly disposed towards
each other such that longitudinal planes in which the sidewalls lie
diverge outwardly each from each other, and the lateral edges of
the coupler heads are angularly disposed towards each other such
that longitudinal planes in which the lateral edges lie diverge
towards each other towards a front of the coupler head.
4. The coupler and receiver assembly of claim 1 in which the rams
are adapted for automated extension and retraction to effect
engagement and disengagement of the pusher vessel with and from the
barge, respectively.
5. The coupler and receiver assembly of claim 3 in which the rams
are adapted for extension and retraction to effect engagement and
disengagement of the pusher vessel with and from the barge,
respectively, the amplitudes of waves of the primary and secondary
waveform surfaces having a combined value less than a distance
equal to that necessary for the coupler heads to be completely
withdrawn from the receiver channels.
6. The coupler and receiver assembly of claim 5 in which relative
vertical movement between the pusher vessel and barge is enabled
when the crests of waves are completely withdrawn from troughs of
opposing waveform surfaces.
7. The coupler and receiver assembly of claim 6 in which relative
horizontal movement of the pusher vessel is limited when the
coupler heads are at least partially within the receiver
channels.
8. The coupler and receiver assembly of claim 7 in which the
primary waveform surface is provided on both lateral edges of the
coupler heads, and the secondary waveform surfaces are provided on
both the first and second sidewalls of the receiver channels.
9. The coupler and receiver assembly of claim 1 in which the
respective waveform surfaces of the lateral edges of the coupler
heads and the sidewalls of the receiver channels have an amplitude
greater than zero, but less than a value representing a distance of
a pitch of the waveform.
10. The coupler and receiver assembly of claim 9 in which a ratio
of the amplitude to pitch is 1:7.
11. A coupler and receiver assembly for maintaining a water level
position of a pusher vessel within a stern notch of a barge during
a lightering operation, the assembly comprising: a pair of rams
provided on lateral sides of the pusher vessel, a coupler head
attached to each of the rams, the coupler head having lateral edges
angularly disposed towards each other at the front end of the
coupler head, receiver channels for receiving each coupler head
provided on the barge, each receiver channel comprising first and
second generally opposed sidewalls, the sidewalls being angularly
disposed away from each other at the longitudinal opening of the
receiver channel, the angular disposition of the sidewalls being
equal but opposite to the angular disposition of the lateral edges
of the coupler head, each of the coupler heads comprising lateral
edges having a primary waveform surface with a plurality of
rounded, non-angular projections, each of the first and second
sidewalls having similar secondary waveform surfaces with a
plurality of rounded, non-angular projections adapted to mate with
the lateral edges of the coupler heads, the rams being adapted for
extraction and retraction to maneuver the coupler heads into
engagement with and disengagement from the receiver channels,
whereby the primary waveform surfaces of the lateral edges of the
coupler heads are capable of being brought into mating engagement
with the secondary waveform surfaces of the first and second
sidewalls of the receiver channels to secure the pusher vessel
within the stern notch of the barge.
12. The coupler and receiver assembly of claim 11 in which the
pusher vessel is restricted from relative vertical movement with
respect to the barge when crests of a wave of a first waveform
surface lie completely within troughs of an opposing second
waveform surface.
13. The coupler and receiver assembly of claim 12 in which the
barge is adapted for relative vertical movement with respect to the
pusher vessel when the barge is subject to load variations, the
rams being adapted for retraction to bring the crests of the wave
of the first waveform surface out of engagement with the troughs of
the opposing second waveform surface, the coupler heads and
receiver channels being adapted to slide with respect to each other
in a vertical direction when the crest of the first waveform
surface is not overlapping the crest of the second waveform
surface.
14. The coupler and receiver assembly of claim 13 in which relative
horizontal movement of the pusher vessel is limited when the
coupler heads are at least partially within the receiver
channels.
15. The coupler and receiver assembly of claim 11 in which the
respective waveform surfaces of the lateral edges and sidewalls
have an amplitude greater than zero, but less than a value
representing a distance of a pitch of the waveform.
16. The coupler and receiver assembly of claim 15 in which a ratio
of the amplitude to pitch is 1:7.
17. An assembly for coupling a first vessel with a second vessel,
the assembly comprising: a ram provided on the first vessel; a
coupler head attached to the ram; and a receiver channel provided
on the second vessel for receiving the coupler head, with the
receiver channel including first and second sidewalls, wherein the
coupler head includes first and second lateral edges, with at least
one of the lateral edges having a primary waveform surface
presenting a plurality of curved, non-angular projections, and at
least one of the first and second sidewalls of the receiver channel
having a similar secondary waveform surface adapted to mate with
the lateral edge of the coupler head having the primary waveform
surface.
18. In a system for selectively coupling a first vessel with a
second vessel, wherein the system includes-- a first ram including
a first coupler head, the first ram being mounted on the first
vessel so as to be selectively extendable outwardly from a first
side of the first vessel; a first receiver channel provided on a
first side of a notch in the second vessel, oriented substantially
vertically, and operable to receive the first coupler head when the
first vessel is located within the notch and the first ram is
extended; a second ram including a second coupler head, the second
ram being mounted on the first vessel so as to be selectively
extendable outwardly from a second side of the first vessel; and a
second receiver channel provided on a second side of the notch in
the second vessel, oriented substantially vertically, and operable
to receive the second coupler head when the first vessel is located
within the notch and the second ram is extended; the improvement
comprising: the first and second coupler heads each having left and
right sides, with each of the left and right sides including a
coupler head surface presenting a first plurality of low amplitude,
rounded projections; and the first and second receiver channels
each having left and right sides, with each of the left and right
sides including a receiver channel surface presenting a second
plurality of low amplitude, rounded projections, wherein the first
and second pluralities of low amplitude, rounded projections
interact so as to allow for vertical sliding movement between each
coupler head and its respective receiver channel without requiring
full withdrawal of the coupler head from the receiver channel,
thereby allowing for relative vertical movement between the first
and second vessels while substantially eliminating other relative
movement.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This present continuation patent application is related to
and claims priority benefit of an earlier-filed non-provisional
patent application of the same title, Ser. No. 11/345,792, filed
Feb. 2, 2006, and an even earlier filed provisional patent
application Ser. No. 60/649,849, filed Feb. 2, 2005. The identified
earlier-filed applications are hereby incorporated by reference
into the present application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of marine
equipment, particularly, the art of connecting tugboats or pusher
vessels with barges or other non-powered vessels which are equipped
with a notch in the stern of the barge for receiving a tug or
pusher vessel therein.
[0004] 2. Description of the Prior Art
[0005] Barges are used to transport cargo on water, but have no
self-propelling mechanisms, and rely primarily on tugboats or other
pusher vessels for movement from one location to another. There
exist many types of connections for coupling tugboats to barges,
and the particular form of connection used depends on the marine
environment in which the transportation takes place. As can be
expected, a more secure coupling arrangement is required to
maintain the connection of the tugboat to the barge in rough
waters. For example, when a barge is used to transport oil, the
coupling of the tugboat to the barge, the loading of the barge, and
the actual pushing of the loaded barge take place out in open sea
and are subject to substantial waves. It is imperative that the tug
boat be securely connected to the barge to prevent the tug boat
from being tossed about against the barge, or substantial damage
and injury can occur.
[0006] A stable form of connection is provided through the use of
extendable ram devices on the tug boat which interconnect with
receivers on the barge. An example of this extendable ram and
receiver configuration is shown in FIGS. 1 and 2 wherein a tug boat
or pusher vessel 14 is connected to a barge 10. This connection is
achieved by the bow of tug 14 entering a generally U-shaped or
V-shaped notch 12 on barge 10. Once the tug 14 is within notch 12,
rams 16 are extended from tug 14 into receivers 18 of the barge 10.
The connecting rams typically have a drive mechanism that will
generate sufficient force to securely hold tug 14 within notch 12
of barge 10. A connection of this type is shown in U.S. Pat. No.
3,512,495 to Fletcher in which a hydraulically extendable shaft is
mounted on the port and starboard sides of the bow of the tug boat,
and the cylindrical shaft of the tug is inserted into a circular
receiver or housing mounted on the port and starboard walls of the
notch within the barge.
[0007] This type of connection is suitable when the barge maintains
a fixed load and the tug boat merely transports the barge. However,
a tug boat must frequently transport a barge to a first destination
where it receives a load, and then transport the barge to a second
destination where the barge is unloaded. During the two operations,
the respective water levels of the tug boat and barge will change
relative to each other as the load weight is affected. For example,
when the barge is empty, it will sit in the water relatively high.
As the barge is loaded, the weight of the load will cause the barge
to sit lower in the water. However, because no weight change is
made to the tug boat itself, the water line of the tug boat remains
constant. If the tug boat were to remain fixedly connected to the
barge during the loading operation, the weight load would push the
tug boat down into the water, with possibly disastrous
consequences. The tug boat must, however, maintain some degree of
connection with the barge during loading, otherwise the waves from
the rough waters may prevent realignment and re-attachment.
Therefore, the connection must permit the relative levels of the
tug boat and barge to change as the weight load varies. The process
by which the tug boat adjusts its position to the coupled barge as
the weight load is changed is called lightering.
[0008] As shown in FIG. 1, certain coupler systems provide vertical
channels 20 on the port and starboard sides of notch 12 in barge 10
for receiving the rams 16. A coupler system of this type is shown
in U.S. Pat. No. 4,688,507 to Kuhlman et al. The vertical channels
20 extend along the top to bottom height of barge 10 and have a
wedge shape configuration which opens up in an inboard direction.
Rams 16 are provided with a coupler head 22 having a similar wedge
shape configuration, as shown in FIGS. 3 and 4, which are oriented
on the rams to mate with the wedge shape configuration of the
vertical channels 20. A series of teeth 24 are arranged along the
sidewalls of the vertical channels 20 as shown in FIGS. 6 and 7.
Similarly, a series of teeth 26 are arranged along the lateral
sides of ram coupler heads 22 as shown in FIG. 4. As ram heads 16
are extended and brought into engagement with vertical channel
receivers 20, their respective teeth interlock. The depth of the
teeth permit sufficient engagement to prevent relative vertical
movement of the tug boat with respect to the barge.
[0009] To permit the relative vertical movement of the barge with
respect to the tug boat, the rams are retracted a sufficient
distance so that the teeth 26 of coupler head 22 come out of
interlocking engagement with the teeth 24 of vertical channel
receiver 20. The distance of retraction must be enough so that the
tips of teeth 26 can clear the tips of teeth 24 so relative
vertical movement can occur. Any contact between the tug coupler
head and the barge during vertical motion with this type of
connection causes the tug ram to turn and makes reengagement
difficult. Full disconnection is required to allow relative
vertical movement between the tug and barge. The operation of the
rams is mechanically and electrically controlled as fully explained
in the Kuhlman et al U.S. Pat. No. 4,688,507 and is now well known
to those having skill in the art.
[0010] Full disconnection results in loss of longitudinal and tug
roll control. Any time the ram disengages from secure engagement
with the receiver, there is potential for mishap, especially in the
heavy waters out at sea. Specifically, anytime that the coupler
becomes disengaged, the tug boat is allowed to roll.
[0011] Accordingly, it is desirable to minimize the degree of
disengagement of the ram from the receiver channel during the
lightering operation so that the ability for respective vertical
movement between the tug boat and barge is maximized, while the
potential for tug boat roll and loss of longitudinal control is
minimized. It is also desirable to minimize the amount of time it
takes to disengage the ram coupler head from engagement with the
receiver channel long enough for the lightering adjustment to be
made, then to reengage the ram coupler head with the receiver
channel to reestablish a secure connection.
SUMMARY OF THE INVENTION
[0012] In accordance with one embodiment, the invention comprises a
tug barge lightering connection system of the type comprising a ram
equipped with a coupler head for engagement with a vertical
receiver channel of a barge, which is adapted to minimize the
degree of disengagement of the ram from the receiver channel during
the lightering operation so that the ability for achieving
respective vertical movement between the tug boat and barge during
the lightering operation is maximized, while the potential for
unintentional longitudinal movement is minimized. The coupler head
of the tug boat ram is wedge shaped and its lateral edges are
provided with a waveform surface. The vertical receiver channels of
the barge have a complementary wedge shape for receiving the ram
coupler heads. The opposing side walls of the vertical receiver
channels also have a waveform surface that mates with the lateral
edges of the ram coupler heads as they come into engagement with
the receiver channels. The waveform surface of the respective
coupler heads and sidewalls of the receiver channels thus permit an
interlocking engagement to provide a secure vertical connection
between the tug boat and barge. The smooth curves and the absence
of angular edges in the waveform surface of the respective coupler
heads and sidewalls permit smooth incremental relative vertical
movement of the tug boat to the barge during the lightering
operation. The low amplitude of the waves also minimize the degree
of ram disengagement from the receiver channels necessary to effect
vertical movement. The wedge shape entry point of the receiver
channels provide sufficient area for the retraction of the waveform
surface of the coupler heads to disengage from interlocking
connection with the waveform surface of the receiver sidewalls
while still providing longitudinal control of the connection
between tug boat and barge.
[0013] In accordance with another aspect of the invention, the
shape of the waveform on the lateral edges of the coupler heads and
the sidewalls of the vertical receiver channels may vary depending
upon the weight load to which they are subjected. The greater the
load transported by the barge, the greater the amplitude of the
wave may be desired at any given level of ram engagement pressure.
The waveform surface of the vertical channels may be comprised of
discrete sections which can be attached onto the sidewalls of
vertical receiver channels in barges.
[0014] Accordingly, it is an object of the present invention to
provide a lightering connection system between a tug boat and a
barge for maximizing the vertical relative movement efficiency
between a tug boat and a barge during the lightering operation,
while minimizing the loss of secure connection between the tug boat
and the barge during the lightering operation. There has thus been
outlined herein, rather broadly, certain embodiments of the
invention in order that the detailed description thereof may be
better understood, and in order that the present contribution to
the art may be better appreciated. There are, of course, additional
embodiments of the invention that will be described below and which
will form the subject matter of the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0015] FIG. 1 is a side elevation view of a tug boat interconnected
with a barge.
[0016] FIG. 2 is a plan view of a tug boat interconnected with a
barge by insertion of the tug boat within the notch of the barge
and showing the orientation of the rams on a tug boat within the
receivers of the barge.
[0017] FIG. 3 shows a tooth style coupler head and ram to which it
is connected.
[0018] FIG. 4 is a front elevational view of the ram coupler head
of FIG. 3.
[0019] FIG. 5 is a breakaway cross-sectional plan view of the tug
boat and the driving mechanism for extending and retracting the
rams.
[0020] FIG. 6 is a front elevational view of a tooth style receiver
channel on a barge for receiving a ram equipped with a tooth style
coupler head.
[0021] FIG. 7 is a fragmentary cross-sectional view taken along
line 7-7 of FIG. 6 and showing the arrangement of the teeth on the
tooth style receiver channel.
[0022] FIG. 8 is a fragmentary cross-sectional view of the waveform
surface of the helmet and receiver channel vertical faces of the
present invention.
[0023] FIG. 9 is a fragmentary plan view of a tug boat
interconnected with a barge by insertion of a ram and helmet of the
tug boat within the vertical receiver of the barge according to an
embodiment of the present invention.
[0024] FIG. 9A is a fragmentary cross-sectional view taken along
line 9A-9A of FIG. 9.
[0025] FIG. 10 is a plan view showing the lightering operation
required retraction of a ram of the tug boat within the vertical
receiver of the barge according to an embodiment of the present
invention.
[0026] FIG. 10A is a fragmentary cross-sectional view taken along
line 10A-10A of FIG. 10.
[0027] FIG. 11A is a fragmentary cross-sectional view showing the
close engagement between the respective waveform surfaces of the
ram coupler head and the wall of the receiver channel according to
an embodiment of the present invention.
[0028] FIG. 11B is a fragmentary cross-sectional view showing the
relationship between the respective waveform surfaces as the
coupler head is retracted from the receiver channel during
lightering operations.
[0029] FIG. 11C is a fragmentary cross-sectional view showing the
relationship between the respective waveform surfaces as the crests
of the coupler head waveform pass over the crests of the receiver
channel waveform during lightering operations.
[0030] FIG. 11D is a fragmentary cross-sectional view showing the
relationship between the respective waveform surfaces as the
coupler head is extended back into the receiver channel preparing
to secure from lightering operations.
[0031] FIG. 11E is a fragmentary cross-sectional view showing the
reengagement to the secure connection of the respective waveform
surfaces of the ram coupler head and the wall of the receiver
channel.
[0032] FIG. 12 is a perspective view of the vertical channel
receiver of a barge incorporating the waveform surface according to
an embodiment of the present invention.
[0033] FIG. 13 is a cross-sectional view of the vertical channel
receiver taken along line 13-13 of FIG. 12.
[0034] FIG. 13A is a cross-sectional view of a sidewall of the
vertical channel receiver taken along line 13A-13A of FIG. 13.
[0035] FIG. 14 is a front elevational view of the ram coupler head
according to an embodiment of the present invention.
[0036] FIG. 15 is a cross-sectional plan view of the coupler head
as partially engaged with the vertical receiver channel during
lightering operations.
[0037] FIG. 16 is a cross-sectional plan view of the coupler head
as fully engaged with the vertical receiver channel.
[0038] FIG. 17 is a cross-sectional plan view of the coupler head
as mounted on the ram.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Referring now to the drawings in more detail, FIG. 8
generally shows the waveform surface of the present invention.
Unlike the tooth-like projections of the prior-art coupling
systems, waveform surface 30 is comprised of rounded projections
31. This permits an opposing surface of similar configuration to
move smoothly over the projections. Angular, non-rounded edges are
avoided. The waveform surface should have consistent amplitude and
pitch dimensions, amplitude (A) being defined herein as the height
of the wave crests, and pitch (P) being defined as the distance
between wave crests as shown in FIG. 8. The optimum amplitude may
vary depending on the weight load involved in the lightering
operation, but frictional forces and compressive forces provided by
the tug boat rams will play a significant role as well. In any
event, the amplitude must be a value greater than zero, but have a
value less than the pitch. Preferably, the ratio of the amplitude
to pitch should be about 1:7.
[0040] Waveform surfaces 32 and 34 are provided on the lateral
sides 36 and 38 of coupler head, or helmet, 40, respectively, as
shown in FIG. 14. The lateral edges of the coupler head 40, when
viewed in plan from above, are angularly disposed towards each
other and converge slightly at the front of the coupler head, as
best shown in FIG. 17. Vertical channel receiver 42 comprises
sidewalls 44 and 46 which generally oppose each other, but diverge
outwardly from each other towards the channels opening, as shown in
FIGS. 12 and 13. As can be seen in FIGS. 15 and 16, the angular
orientation of the coupler head is complementary to the angular
orientation of the vertical channel receiver 42. Wave form surfaces
50 and 52 are provided on side walls 44 and 46, respectively. The
wave form surfaces may be integrally welded as a single piece
directly on the side wall, or may be provided in sections which are
then attached to the side wall. When adjacent sections are abutted
against each other, it is important to ensure that the connection
joint 54 be smoothed down to avoid any obstructions or raised areas
that detract from the smooth waveform surface, as shown in FIG.
13A. As well understood by those having skill in the art, the
function, structure and arrangement of the laterally positioned
rams and the configuration of their respective coupler heads are
analogous with respect to the port side and the starboard side of
the tug boat. Similarly, the vertical receiver channels on port and
starboard sides of the barge vessel are essentially identical to
each other, except for orientation. Accordingly, discussion
relating to structures for the coupler heads and vertical receiver
channels herein will be understood to be applicable to the
connection system for both the port and starboard positions.
[0041] The interaction between the waveform surfaces on the ram
coupler head and sidewalls of the vertical channel receiver can be
understood by viewing the operation as referenced in the drawings
and aided by the following description. In the usual barge
transportation scenario, a tug boat 14 enters the notch 12 of a
barge 10 equipped with port and starboard vertical receiver
channels of the type well known in the art, as shown in FIGS. 1, 2
and 5. Rams 56 and 58 are powered to extend coupler heads 40 and
60, respectively, from tug boat 14 so that they enter vertical
channel receivers 42 and 62, respectively. As can be seen in FIG.
10, the fore and aft sidewalls 46 and 44 help control longitudinal
movement of the tug boat within the notch of the barge. However,
until the waveform surfaces of coupler head 40 engage the waveform
surfaces of the sidewalls of receiver channel 42, there is no
vertical control. FIG. 10A shows waveform surface 34 of lateral
side 38 of coupler head 40 apart from waveform surface 50 of
sidewall 44 of vertical channel receiver 42. This is the condition
present as the coupler head enters the receiver channel. As the ram
is fully extended, coupler head 40 engages completely with vertical
channel receiver 42, and the lateral edges 38 and 36 of coupler
head 40 bear against vertical channel side walls 44 and 46
respectively. FIG. 9A shows waveform surface 34 of lateral side 38
of coupler head 40 nestled within waveform surface 50 of sidewall
44 of vertical channel receiver 42. In this condition, vertical
control is fully effected, and the relative vertical positions of
the tug boat and barge should remain the same, provided a
sufficient amount of extension force is placed against the
rams.
[0042] FIGS. 11A-11E show the interaction of the waveform surfaces
of the coupler heads with the waveform surfaces of the sidewalls of
the vertical channels over one cycle of movement that takes place
during the lightering operation. In FIG. 11A, the respective
waveform surfaces of coupler head 38 and vertical channel sidewall
44 are in complete engagement, brought about by full extension of
the ram against the vertical channel as shown in FIG. 16. As cargo
is deposited into the barge, its weight will increase and cause the
barge to descend and lie lower in the water. As that occurs, the
tug boat must release its connection otherwise it will be dragged
down into the water as well. FIG. 11B shows, with the release of
extension force by the ram, the primary waveform surface of coupler
head 38 beginning to disengage from the secondary waveform surface
of vertical channel sidewall 44, as shown in FIG. 15. As this
occurs, the incrementally greater weight of the barge causes the
vertical channel sidewall 44 to move downward relative to coupler
head 38. FIG. 11C shows the crest of the waves of the secondary
waveform surface of vertical channel sidewall 44 sliding over the
crest of the waves of the primary waveform surface of coupler head
38. Assuming that the weight differential has been settled, the
rams are again extended to regain vertical movement control. In
FIG. 11D, as the rams are extended, the waveform surfaces are again
brought into engagement. When lightering equilibrium is reached,
the rams are extended to lock the waveform surfaces of the coupler
head and vertical channel sidewall in locking engagement as shown
in FIG. 11E and FIG. 16. In this fashion, the waveform surfaces of
the present invention provide close control over vertical movement
between tug boat and barge, while minimizing loss of horizontal
control. During the entire lightering operation as depicted in
FIGS. 11A-11E, coupler head 40 is able to remain in the confines of
vertical channel 42, as seen in FIGS. 15 and 16, to prevent forward
or backward motion of the tug boat relative to the barge. The
relationship between the depth of the vertical channel receiver 42
and amplitude of the wave crests should be such that when the
primary and secondary waveform surfaces 34 and 50 are moved apart
for lightering operations as shown in FIG. 10A, a sufficient amount
of coupler head 40 remains within the vertical channel receiver 42
as shown in FIG. 10.
[0043] The waveform surface also permits vertically controlled
movement as a function of friction. With the rounded surfaces
provided by the waveform, the transition between the point where a
wave crest emerges out of a trough (as in FIG. 11B), moves over an
opposing wave crest (as in FIG. 11C), and descends back towards
another wave trough (as in FIGS. 11D and 11E) is able to occur more
smoothly with the lower amplitude of the wave crest. It is critical
that reengagement of the coupler head in tight compression with the
receiver channel take place as quickly as possible because the tug
boat is subject to roll whenever the vertical restraint of the
connection is disengaged.
[0044] As shown in FIG. 17, coupler head 40 is shown in
cross-sectional view as seated on the end of ram 56. Support ball
66 is a steel ball and coupler head 40 is secured thereto by the
attachment of a circumferential securing plate 68. The securing
plate forms a collar which retains coupler head 40 on support ball
66. Support ball 66 acts as a swivel for coupler head 40 and allows
coupler head 40 to move to allow coupler head 40 and receiver 42 to
self-align.
[0045] One embodiment of the waveform surface of the present
invention comprises a coupler head whose lateral sides have the
waveform surface integrated therein. This enables existing rams
using a helmet incorporating the tooth-edged coupler to be switched
with a helmet incorporating the waveform surface coupler.
Similarly, the vertical channel receiver may have the waveform
surface integrated into its sidewalls. Alternately, the waveform
surface could be connected to an existing surface by welding or
bolting or the like. Another embodiment provides for the waveform
surface to be installed on vertical channel receiver side walls by
installing in individual sections as shown in FIG. 12. For example,
individual plates can be manufactured and aligned together over the
length of the side wall. Each plate can incorporate a waveform
having four cycles of waves to provide four wave crests. A typical
wave plate incorporating four wave crests would have a width of 20
inches and a length of 28 inches, with each wave crest having a
height of one inch. If desired, wave plates having more than or
fewer than four wave crests can be manufactured.
[0046] In the foregoing description, certain terms have been used
for brevity, clearness and understanding; but no unnecessary
limitations are to be implied therefrom beyond the requirements of
the prior art, because such terms are used for descriptive purposes
and are intended to be broadly construed. Moreover, the description
and illustration of the inventions is by way of example, and the
scope of the inventions is not limited to the exact details shown
or described.
[0047] Certain changes may be made in embodying the above
invention, and in the construction thereof, without departing from
the spirit and scope of the invention. It is intended that all
matter contained in the above description and shown in the
accompanying drawings shall be interpreted as illustrative and not
meant in a limiting sense. Having now described the features,
discoveries and principles of the invention, the manner in which
the inventive tugboat and barge connector and receiver combination
is constructed and used, the characteristics of the construction,
and advantageous, new and useful results obtained; the new and
useful structures, devices, elements, arrangements, parts and
combinations, are set forth in the appended claims.
[0048] It is also to be understood that the following claims are
intended to cover all of the generic and specific features of the
invention herein described, and all statements of the scope of the
invention which, as a matter of language, might be said to fall
therebetween.
* * * * *