U.S. patent application number 10/368292 was filed with the patent office on 2004-08-19 for dock stabilizer.
Invention is credited to Rogerson, L. Keith.
Application Number | 20040159273 10/368292 |
Document ID | / |
Family ID | 32850146 |
Filed Date | 2004-08-19 |
United States Patent
Application |
20040159273 |
Kind Code |
A1 |
Rogerson, L. Keith |
August 19, 2004 |
Dock stabilizer
Abstract
A dock stabilizer is provided that attaches about a piling on a
dock or a pier to stabilize the dock or pier. In one aspect, the
dock stabilizer utilizes a plurality of roller assemblies that are
spaced axially and laterally apart from one another to reduce
twisting or rocking of the dock. At least one of the roller
assemblies may have a roller disposed a predetermined distance from
the surface of the dock to counteract a moment arm and provide
equilibrium on the dock.
Inventors: |
Rogerson, L. Keith; (Isle of
Palms, SC) |
Correspondence
Address: |
DORITY & MANNING, P.A.
POST OFFICE BOX 1449
GREENVILLE
SC
29602-1449
US
|
Family ID: |
32850146 |
Appl. No.: |
10/368292 |
Filed: |
February 17, 2003 |
Current U.S.
Class: |
114/230.1 ;
114/263; 114/264 |
Current CPC
Class: |
E02B 3/064 20130101;
B63B 21/50 20130101 |
Class at
Publication: |
114/230.1 ;
114/263; 114/264 |
International
Class: |
B63B 021/00; E02B
003/00; B63B 035/44 |
Claims
That which is claimed is:
1. A dock stabilizer comprising: a base configured for attachment
about a piling on a dock; and a plurality of roller assemblies
attached to the base, at least one of the plurality of roller
assemblies disposed axially apart from a second one of the
plurality of roller assemblies on opposite sides of the base
substantially parallel to an axis of the piling, at least one of
the roller assemblies having at least one roller disposed apart
from the base.
2. The dock stabilizer of claim 1, wherein the base defines an
aperture therethrough for passage of the piling.
3. The dock stabilizer of claim 3, wherein the base defines a skirt
disposed about the aperture configured for placement through an
opening on the dock.
4. The dock stabilizer of claim 1, further comprising means for
attaching the base to the dock.
5. The dock stabilizer of claim 5, wherein the means for attaching
is selected from the group consisting of a screw, a nail, a bolt,
an adhesive, a clamp, a rivet, and combinations thereof.
6. The dock stabilizer of claim 1, wherein the plurality of rollers
are respectively attached apart from the base by a plurality of
bars.
7. The dock stabilizer of claim 7, wherein the plurality of bars
are between about 2 inches to about 14 inches in length.
8. The dock stabilizer of claim 8, wherein the base and the bars
are made from a material selected from the group consisting of a
metal, a plastic, a wood and combinations thereof.
9. The dock stabilizer of claim 1, wherein the plurality of rollers
is made from a material selected from the group consisting of a
UHMW material, a metal, a plastic, a rubber and combinations
thereof.
10. The dock stabilizer of claim 1, wherein the plurality of
rollers is selected from the group consisting of a wheel, a
cylinder, a tapered roller, and combinations thereof.
11. The dock stabilizer of claim 1, wherein each of the plurality
of rollers has a face, at least one of the faces configured to roll
substantially parallel to the axis of the piling.
12. The dock stabilizer of claim 1, wherein a third one of the
plurality of roller assemblies is disposed laterally apart from the
at least one of the plurality of roller assemblies.
13. A dock stabilizer comprising: a base configured for attachment
about a piling on a dock; and a plurality of rollers attached to
the base, a first roller disposed axially apart from a second
roller such that the base is interposed between the first and
second rollers, a third roller disposed laterally apart from the
first roller such that the piling is interposed between the first
and third rollers, a fourth roller disposed laterally apart from
the second roller such that the piling is interposed between the
second and fourth rollers, the first and third rollers and the
second and fourth rollers cooperably configured to equalize a
moment arm formed substantially perpendicular to the piling and
parallel to the dock.
14. The dock stabilizer of claim 13, wherein the base and the bars
are made from a material selected from the group consisting of a
metal, a plastic, a wood and combinations thereof.
15. The dock stabilizer of claim 13, wherein the base defines an
aperture therethrough for passage of the piling.
16. The dock stabilizer of claim 15, wherein the base defines a
skirt configured for insertion through an opening in the dock.
17. The dock stabilizer of claim 13, further comprising means for
attaching the base to the dock.
18. The dock stabilizer of claim 17, wherein the means for
attaching is selected from the group consisting of a screw, a nail,
a bolt, an adhesive, a clamp, a rivet, and combinations
thereof.
19. The dock stabilizer of claim 13, wherein the plurality of
rollers are respectively attached apart from the base by a
plurality of bars.
20. The dock stabilizer of claim 19, wherein the plurality of bars
are between about 2 inches to about 14 inches in length such that
the plurality of rollers are disposed from about 2 inches to about
14 inches from the base.
21. The dock stabilizer of claim 13, wherein the base and the
plurality of rollers is made from a material selected from the
group consisting of a UHMW material, a metal, a plastic, a rubber,
a wood and combinations thereof.
22. The dock stabilizer of claim 13, wherein the plurality of
rollers are selected from the group consisting of a plurality of
wheels, a cylinder, a tapered roller, and combinations thereof.
23. The dock stabilizer of claim 22, wherein each of the plurality
of wheels has a face, at least one of the faces configured to roll
substantially parallel to the axis of the piling.
24. The dock stabilizer of claim 13, wherein each of the plurality
of rollers has a face configured to roll substantially parallel to
the axis of the piling.
Description
BACKGROUND OF THE INVENTION
[0001] A pier or dock is known to extend from a marina or shoreline
into a body of water to provide a landing for watercraft, or to
provide limited access to the water such as for fishing. An end of
the pier is usually attached to an offshore piling in the water.
Typically, the end of a smaller pier is movably attached to the
piling in order for the end of the pier to move up and down in
response to tidal, wave or wake actions. Otherwise a small pier,
for instance, could be submerged and unusable during a high
tide.
[0002] Conventional roller arrangements are known to permit the
pier to rise and lower around pilings as the tide comes in and
recedes. However, some piers known as "finger piers" with
relatively narrow widths and long lengths present lateral stability
problems, which conventional rollers do not address. Specifically,
conventional roller arrangements do not adequately stabilize the
finger pier to prevent lateral instability or twisting. For
example, a boat wake acting on a 4-foot wide finger pier can turn
the finger pier into a "rolling log," making it difficult to walk
upon.
[0003] Twisting is due to the creation of a "moment" that results
when a first force is applied on one part of the pier without an
equal and opposite force directly along the first force's line of
action. More specifically, the moment urges a rotation about a
given point or axis, which may be better understood with reference
to a moment arm or lever arm corresponding to the moment.
[0004] The moment arm is a perpendicular distance d between the
line of action of a force F and a center of the moment. A magnitude
of the moment of the force F acting about the point is directly
proportional to the distance d of the force F from the point.
Therefore, the magnitude of the moment can be defined as the
product of the force F and the moment arm d expressed as:
magnitude of moment=force.times.distance=F.times.d.
[0005] If the moment is to be taken about the point due to the
force F, then in order for the moment to develop, the line of
action cannot pass through that point. Alternatively, if the line
of action does go through the point, the moment is zero because the
magnitude of the moment arm is zero; thus, no twisting will
occur.
[0006] Imagine two people standing on either side of a pier that is
movably attached to a piling. Further assume that both people weigh
200 pounds (lbs) and stand 12 inches (in.) on laterally opposite
sides of the piling. Each person creates a moment of 2,400 in.-lbs
(200 pounds.times.12 inches). The center of the moments in this
case is zero since 2,400 in.-lbs minus 2,400 in.-lbs results in a
total moment of zero; i.e., a state of equilibrium exists on the
pier. If one of the people would suddenly climb aboard a boat tied
alongside the pier, the weight of the remaining person would no
longer be counterbalanced. The pier would twist down on the side of
the remaining person. In other words, the force (weight) F of the
person still standing on the pier would have created a moment as
defined above.
[0007] A device is needed that smoothly raises and lowers the pier
and also stabilizes the pier to reduce rolling and twisting under
most water surface conditions.
BRIEF SUMMARY OF THE INVENTION
[0008] In general, the present invention is directed to a dock
stabilizer that permits a dock or pier to smoothly raise and lower
in response to most normal tidal, wave, and wake actions.
Furthermore, the dock stabilizer reduces rolling and twisting
actions of the pier to make the pier easier to walk upon. The
component parts of the invention are simple, reliable, and
economical to manufacture and use.
[0009] In one aspect of the invention, a dock stabilizer is
provided with a base for attachment about a piling on a dock. A
plurality of rollers are attached to the base with a first roller
disposed axially apart from a second roller such that the base is
interposed between the first and second rollers. A third roller is
located laterally apart from the first roller such that the piling
is interposed between the first and third rollers. A fourth roller
is located laterally apart from the second roller such that the
piling is interposed between the second and fourth rollers. The
first and third rollers and the second and fourth rollers cooperate
to equalize a moment arm formed substantially perpendicular to the
piling and parallel to the dock to reduce twisting and rolling of
the dock.
[0010] Other aspects and advantages of the invention will be
apparent from the following description and the attached drawings,
or can be learned through practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above and other aspects and advantages of the present
invention are apparent from the detailed description below in
combination with the drawings, in which:
[0012] FIG. 1 is a perspective view of a dock stabilizer according
to an aspect of the present invention;
[0013] FIG. 2 is a perspective view of an unstabilized finger
pier;
[0014] FIG. 3 is a partial perspective view of a dock rollingly
disposed about a piling in a conventional manner;
[0015] FIG. 4 is a perspective view of the dock stabilizer
stabilizing a finger pier;
[0016] FIG. 5 is another perspective view of the dock stabilizer
similar to FIG. 4 in which the finger pier is stabilized during use
by a user; and
[0017] FIG. 6 is a partial plan view of another embodiment
according to a further aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Detailed reference will now be made to the drawings in which
examples embodying the present invention are shown. The drawings
and detailed description provide a full and detailed written
description of the invention and the manner and process for making
and using it so as to enable one skilled in the pertinent art to
make and use it. The drawings and detailed description also provide
the best mode of carrying out the invention. However, the examples
set forth herein are provided by way of explanation of the
invention and are not meant as limitations of the invention. The
present invention thus includes modifications and variations of the
following examples as come within the scope of the appended claims
and their equivalents.
[0019] The present invention is generally directed to a dock
stabilizer with a plurality of roller assemblies that permit the
dock or pier to smoothly raise and lower in response to most normal
tidal, wave, and wake action. Furthermore, the dock stabilizer
reduces rolling or twisting action of the pier to make the pier
easier to walk upon. Although the exemplary dock stabilizer,
described in detail below is made of marine-grade aluminum and is
square in shape, the invention is not limited to the exemplary
materials, sizes, and shapes discussed herein. For instance, the
invention is intended for use with any size of pier, dock, and the
like and with pilings of various sizes and shapes.
[0020] The Figures show a dock stabilizer generally designated by
the numeral 10. The dock stabilizer 10 includes a plurality of
roller assemblies 12, 20 with a plurality of rollers 14, 16, 22, 24
attached by bars 18a, b, c, d to a frame assembly or base 26. The
dock stabilizer 10, the bars 18a, b, c, d, and the base 26 are
manufactured of marine-grade aluminum and are therefore virtually
impervious to attack from salts and other corrosives found in or
near most bodies of water, such as oceans, harbors, and inland
waterways. It should be understood, however, that the foregoing
elements of the dock stabilizer 10 can be made from any type of
metal, plastic such as high density polyurethane (HDPE), treated
wood, or other durable material. It should be further understood
that fewer or additional rollers and bars of various sizes and
shapes can be provided. Therefore, the invention is not limited to
the illustrated enhancements.
[0021] With particular reference to FIG. 1, a perspective view of
the dock stabilizer 10 shows a first roller assembly 12 with a
first roller 14 and a second roller 16 attached to the base 26 via
a plurality of bars 18a, b. Also in this example, a second roller
assembly 20 is disposed apart from the first roller assembly 12 and
is similarly attached to the base 26 via a plurality of bars 18c,
d. The rollers 14, 16, 22, 24 have respective rolling faces 14a,
16a, 22a, 24a that roll substantially parallel to an axis A of a
piling P (see FIG. 4). The base 26 and the roller assemblies 12, 20
are shown squarely arranged to accommodate the square-shaped piling
P (see FIG. 4) but other arrangements can be provided to
accommodate any shape of piling as will be described below.
[0022] As shown in FIG. 1, the first roller 14 and the second
roller 16 are axially aligned on opposite sides of the base 26.
Similarly, the second roller assembly 20 has a third roller 22 and
a fourth roller 24 disposed opposite each other on opposite sides
of the base 26. FIG. 1 further shows each of the bars 18a, b, c, d
with respective portions on axially opposite sides of the base 26.
Bars 18a, b, c, d have portions with lengths L.sub.1, L.sub.2,
which in this example are between from about 2 inches to about 14
inches in length such that the rollers 14, 16, 22, 24 are disposed
from about 2 inches to about 14 inches from the base 26. Although
the bars 18a, b, c, d can be any desired length, 2 inches to about
14 inches control rocking of a finger pier of about 4 feet in width
by reducing the moment about the piling P toward zero. An operation
of the dock stabilizer 10 will be described in further detail
below.
[0023] In this exemplary embodiment the rollers 14, 16, 22, 24 are
made from an ultra high molecular weight (UHMW) material to
withstand most dockside conditions. However, the rollers 14, 16,
22, 24 can be made of metal such as aluminum or stainless steel, or
a plastic such as high density polyurethane (HDPE), a rubber or any
other durable material. It should also be noted that although the
plurality of rollers 14, 16, 22, 24 are illustrated in FIG. 1 as
cylinders, they can be wheels, tapered rollers, or other rolling
mechanisms suitable for rollingly stabilizing the dock D in
relation to the piling P.
[0024] Also shown in FIG. 1, the base 26 of the dock stabilizer 10
includes a protrusion or skirt 28, which is sized to fit about an
outer surface of the piling P. The base 26 and skirt 28 define a
complementary opening 30 through which the piling P passes. The
base 26 further includes means for attaching the base to the dock
D, such as a plurality of holes 32a and complementary bolts 32b
(see FIG. 4). In this example, the holes 32a are defined about a
perimeter of the base 26 for insertion of the bolts 32b into the
dock D. It is to be noted that any suitable means for attaching the
base 26 to the dock D can be used in lieu of or in addition to
holes 32a and bolts 32b, such as nails, screws, rivets and the
like. Additionally, adhesives, clamps or other attachment
mechanisms may be used to secure the base 26 to the dock D.
[0025] FIG. 1 further shows a plurality of additional guide rollers
34a, b disposed laterally apart from each other about the base 26
substantially perpendicular to the first and second roller
assemblies 12, 20. The guide rollers 34a, b assist with an up and
down movement of the dock D as the tide goes in and out or as wake
and wave actions cause the dock D to rise and fall under normal
circumstances.
[0026] In FIG. 2 a piling P' is shown passing through an opening O'
of an unstabilized dock D'. With a weight W' placed on one side of
the unstabilized dock D', the unstabilized dock D' twists due to
creation of a moment by a force F' of the weight W'. By way of
example, if the weight W' weighs 200 lbs and sits approximately 12
inches (d') from the piling P', the weight W' creates a moment of
2,000 in.-lbs (200 lbs.times.12 inches). Since there is no
equalizing force to offset the moment created by the weight W', the
dock D' is twisted as indicated by a twist angle .theta. relative
to a horizontal plane H.
[0027] By way of comparison, FIG. 3 shows a conventional roller
assembly R that allows the dock D' to raise and lower smoothly
along the piling P'. However, the conventional roller assembly R
does not counteract the moment as described above with respect to
FIG. 2 to prevent the dock D' from twisting.
[0028] FIG. 4 shows the dock stabilizer 10 operably placed about
the piling P with the roller assemblies 12, 20 aligned
substantially parallel to an axis A of the piling P. In this
example, the base 26 is secured to the dock D by bolts 32b, as
described above. The roller assemblies 12, 20 zeroize moments to
provide equilibrium on the dock. More specifically, the length
L.sub.1 of the arms 18a, b, c, d cooperate with the opposing length
L.sub.2 of the bars 18a, b, c, d to counteract moments (see FIG.
1). This aspect of the invention may be better understood with
respect to an exemplary operation of the dock stabilizer 10 with
reference to FIG. 5.
[0029] As shown in FIG. 5, a user U weighing 200 lbs creates a
moment of 2,000 in.-lbs in a similar manner as described above.
Also as described with respect to FIG. 2 above, the 2,000 in.-lbs
moment would usually cause the dock D to twist to a side upon which
the user U is standing. However, a movement M.sub.1 of the first
roller 14 and the bars 18a, b is opposed by a movement M.sub.2 of
the roller 24 and the bars 18c, d (see FIG. 1) on the underside of
the dock D. In this example, the length L.sub.1 of bars 18a, b is
offset by the length L.sub.2 of bars 18c, d to counteract the
moment of the user U and prevent the dock D from twisting. In other
words, as the user U walks along one side of the dock D in FIG. 5,
the first roller 14 and the fourth roller 24 contact the piling P
to equalize the moment of the user U.
[0030] As briefly introduced, alternative embodiments of the
invention will accommodate different sizes and shapes of various
pilings and the like. For instance, in another aspect shown in FIG.
6, a partial top plan view of a roller assembly 112 is shown. A
similar roller assembly (not shown) would face substantially
opposite of the roller assembly 112. In this embodiment, rollers
114a, b, c are attached to a base 126 via bars 118a, b and contact
a piling P" in a manner similar to the foregoing embodiment. In
this alternative arrangement, a rolling face 114b' rolls
substantially parallel to an axis A" of the piling P". The
remaining rollers 114a, c may intermittently contact the piling P"
during times of specific wave or tidal actions that move the dock
D" from side to side.
[0031] In a further aspect of the invention, the rollers 114a, b, c
are self-aligning rollers that automatically contact and align on
the surface of the piling P" as the dock D" moves from side to
side; i.e., one or more faces of the rollers 114a, b, c contact and
conformingly adjust to any shape of the surface of the piling
P".
[0032] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the scope and spirit of the invention. For
example, specific shapes of various elements of the illustrated
embodiments may be altered to suit particular applications. It is
intended that the present invention include such modifications and
variations as come within the scope of the appended claims and
their equivalents.
* * * * *