U.S. patent number 3,752,102 [Application Number 05/182,744] was granted by the patent office on 1973-08-14 for floating dock or the like and floatation unit for use therewith.
This patent grant is currently assigned to Woodall Industries Inc.. Invention is credited to Robert A. Shuman.
United States Patent |
3,752,102 |
Shuman |
August 14, 1973 |
FLOATING DOCK OR THE LIKE AND FLOATATION UNIT FOR USE THEREWITH
Abstract
A floating dock, raft or the like is made with special plastic
floatation units. The floatation units consist of a pair of vacuum
formed polyethylene sheets heat sealed together at peripheral
flanges thereof. This flange is nailed to the bottom of joists
which support the deck material of the dock.
Inventors: |
Shuman; Robert A. (Plymouth,
MI) |
Assignee: |
Woodall Industries Inc. (East
Detroit, MI)
|
Family
ID: |
22669828 |
Appl.
No.: |
05/182,744 |
Filed: |
September 22, 1971 |
Current U.S.
Class: |
114/267 |
Current CPC
Class: |
B63G
8/18 (20130101); B63B 35/34 (20130101) |
Current International
Class: |
B63G
8/00 (20060101); B63G 8/18 (20060101); B63B
35/34 (20060101); B63b 035/00 () |
Field of
Search: |
;114/.5R,.5F,123,234
;9/11R,11A,8R,8P ;73/305,309,311 ;137/165,192,409 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Buchler; Milton
Assistant Examiner: Sotelo; Jesus D.
Claims
What is claimed is:
1. A floating load supporting structure comprising a framework
having a plurality of parallel joists, a deck mounted on said
joists and a plurality of floatation units positioned between and
supporting said joists, said floatation units being made from upper
and lower thin walled plastic members joined at peripheral flange
portions thereof to define a water tight compartment between said
members, said flange portions being disposed in a horizontal plane
located intermediate the upper and lower extremities of said
floatation units, and fastener means extending upwardly through
said flange portions into said joists to secure said flange
portions to said joists.
2. The structure set forth in claim 1 in which one thin walled
member of said floatation unit is upwardly dished from said flange
and in which the other thin walled member of said floatation unit
is downwardly dished from said flange.
3. The structure set forth in claim 1 in which said floatation unit
flange portions are heat sealed together.
4. The structure set forth in claim 1 in which said joists comprise
lumber of greater height than width.
5. The structure set forth in claim 1 in which one of said
floatation unit members incorporates an upwardly formed central
portion having a substantially flat upper wall and in which the
other floatation unit members incorporates a central downwardly
formed portion having an arcuate wall.
6. The structure set forth in claim 1 in which a lower one of the
members of said floatation units incorporates outwardly projecting
ribs supportingly connected to said flange portions on the lower
side thereof.
7. A floatation unit for floating docks, rafts or the like
comprising a pair of formed synthetic resinous top and bottom
sheets, said sheets having peripheral flanges sealed together to
define a water tight compartment in the space between said sheets,
said top sheet being upwardly formed in the area thereof bounded by
its said flange and being unobstructed in areas above its said
flange on opposite sides thereof to permit a pair of joists or the
like to be supported thereon, said bottom sheet having load
supporting ribs formed therein and connected to its said flange to
reinforce said flanges against downward deflection.
8. The structure set forth in claim 7 in which said top sheet has a
central upwardly deformed portion located entirely above the plane
of said flange portions and in which said bottom sheet has a
downwardly deformed portion located entirely beneath the plane of
said flange portions.
9. The structure set forth in claim 8 in which said top sheet is
provided with a raised generally flat top wall at the upper end
thereof and in which said bottom sheet is formed with a depressed
arcuate wall at the lower end thereof.
10. The structure set forth in claim 7 in which the flange portions
of said sheets are heat sealed together.
11. The structure set forth in claim 7 in which one of said sheets
is formed with inwardly depressed reinforcing ribs.
12. The structure set forth in claim 7 in which said flange
portions are located in a plane disposed above a point midway
between the top of said top sheet and the bottom of said bottom
sheet.
13. The structure set forth in claim 7 in which each of said sheets
is provided with a peripheral flange extending entirely therearound
and in which said flanges are heat sealed together.
14. The structure set forth in claim 13 including load supporting
ribs deformed outwardly from said lower sheet and merging with the
flange of said lower sheet to provide columnar support against
downward deflection of said lower sheet flange.
Description
SUMMARY OF THE INVENTION
It has been common practice in the construction of rafts, floating
docks and other water buoyant devices to employ barrels or drums as
floatation units. Four or more steel barrels, when they are empty,
will serve to support a considerable weight of framing and deck
material well above the water line. While the use of steel barrels
in such construction has been a useful expedient, this practice has
a number of serious drawbacks. Docks and the like made with steel
barrels are extremely heavy and are quite difficult to put in and
take out of the water. The steel of the barrels tends to rust and
specially designed brackets are often needed to secure the barrels
to the framework of the dock or raft. Furthermore, the type of
framework required with barrels must necessarily be of a sizable
and expensive nature. Also, the decking is often supported at a
greater height above the water than is desirable. The present
invention relates to a floating dock, raft or similar device and a
special floatation unit which is used therein in lieu of steel
barrels. The arrangement of the present invention has a number of
marked advantages over prior floating docks and raft
constructions.
The device of the present invention is relatively easily
constructed by an individual having few or no special skills. Apart
from the special floatation units, a dock, raft or the like can be
constructed with conventional, readily available, low cost
materials. The amount of material needed for the framework is
particularly minimal and low in cost. The resulting product is
relatively light in weight, low in cost and requires minimal
maintenance. Furthermore, it is of a durable and relatively rugged
character.
The floatation units themselves can be manufactured and sold at a
reasonable cost, they possess a high structural strength for their
weight, and they are uniquely suited for use in the construction of
floating docks, rafts, diving platforms and other floating devices
operable to support humans or materials on water. The floatation
units are substantially maintenance free, yet they are easily
repaired if damaged.
The foregoing advantages of the present invention will be readily
apparent from the ensuing description of the preferred embodiments
of the invention when taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a floatation unit constructed
in accordance with the present invention;
FIG. 2 is an end elevational view on a reduced scale of the
structure illustrated in FIG. 1;
FIG. 3 is a top plan view of a floating dock made with the
floatation unit of FIGS. 1 and 2, most of the decking of the dock
being broken away to illustrate the subjacent structure;
FIG. 4 is an enlarged sectional view of the structure illustrated
in FIG. 3, taken along the line 4-4 thereof; and
FIG. 5 is a top plan view of a raft made in accordance with the
present invention, the major portion of the decking of the raft
being removed to illustrate the subjacent structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The floating dock of FIGS. 3 and 4 employs four floatation units of
the type shown in FIGS. 1 and 2. The floatation unit per se is
designated by the numeral 10 and is best seen by reference to FIGS.
1, 2 and 4. The unit 10 is made from an upper plastic sheet 12 and
a lower plastic sheet 14. The sheets 12 and 14 are desirably of
polyethylene material and are vacuum formed by means of the method
and apparatus shown in U. S. Pat. Nos. 3,242,245 and 3,250,660. The
upper sheet 12 has a central upwardly dished portion 16 which is
surrounded at its lower end by a planar peripheral flange 18. The
lower sheet 14 has a downwardly dished central portion 20 which is
surrounded at its upper end by a planar peripheral flange 22. The
formed or upwardly dished portion 16 of the top sheet 12 will be
seen to include a generally flat horizontal top wall 26 which is
connected to the flange 18 by downwardly and outwardly inclined
side walls 28 and end walls 29. The downwardly dished portion 20 of
the lower sheet 14 will be seen to include a semi-cylindrical wall
30 which blends with straight side walls 32 at its upper ends. The
straight side walls 32 connect the semi-cylindrical wall 30 with
the flange 22. Generally flat end walls 33 enclose the lower dished
portion 20 at the opposite ends thereof and merge with the flange
22.
Both the top and bottom sheets 12 and 14 are provided with suitable
strengthening ribbing which contributes to the strength and
rigidity of the floatation unit 10. Inwardly deformed ribs 34 are
formed in the upper sheet end walls 29 and extend upwardly from the
flange 18 to the top wall 26. Inwardly deformed transverse ribs 36
are formed in the top wall 26 and side walls 28 and extend from one
side of the floatation unit to the other side thereof. The lower
sheet 14 is similarly provided with inwardly deformed ribs 38 in
the end walls 33 thereof and with inwardly deformed transverse ribs
40 in the wall 30 and walls 32 thereof. The ribs 40 extend from the
portion of the flange 20 at one side of the unit to the portion of
the flange 20 on the opposite side thereof. Load supporting
vertical ribs 42 are formed on all sides of the lower sheet dished
portion 20 in columnar supporting relation to the flange 22. It
will be seen that the ribs 42 extend downwardly from the flange 22
and outwardly from the walls 32 and 33. The ribs 42, of course,
constitute outward deformations of the walls 32 and 33. A plugged
hole 44 is formed in the floatation unit 10 between the flanges 18
and 22 to facilitate the emptying of water from the unit in the
event of a leak.
The two sheets 12 and 14 are heat sealed together at their flanges
18 and 22. The flanges 18 and 22 thus become one solid flange for
the floatation unit which will hereafter be referred to as the
flange 18-22. This flange will be seen to be uninterrupted on its
upper surface and supported on its lower surface by the ribs 42.
The formed or dished portions 16 and 20 of the sheets 12 and 14
define a substantially water tight compartment 45 which normally
contains only air at atmospheric pressure and provides the unit 10
with the desired buoyancy.
The floatation unit 10 may be utilized to construct various
floating structures such as floating docks, rafts, diving platforms
or the like. Such structures may differ in size or shape although
they have certain common structural features. One such structure in
the form of a floating dock is illustrated in FIG. 3. This dock
will be seen to have a framework which includes a plurality of
parallel long joists 46 and parallel short joists 48 set at right
angles to the long joists 46. Joists in the form of angular struts
50 connect the joists 46 and 48 at the outer ends thereof. The
joists 46 and 48 as well as the struts 50 desirably consists of
lumber such as standard 2 .times. 6 inch lumber. Right angle steel
brackets 52 are used at the junctures of joists 46 and 48 while
brackets 56 are used at the joints between struts 50 and the joists
46 or 48. The joists 46 and 48 are set on edge on the upper
surfaces of the flanges 18-22 of four floatation units 10 while a
deck in the form of plywood panels 58 is fastened to the joists 46
and 48 by nails 60. As seen in FIG. 4, the plywood deck panels 58
rest on the upper edges 62 of the joists 46 while lower edges 64 of
the joists 46 rest on the upper surface of the flanges 18-22. The
nails 60 are also used to secure the joists 46 and 48 to the
flanges 18-22 of the floatation units 10, the nailing being
accomplished from the underside of the flanges. The joists 46 and
48 are thus positioned in vertical attitudes and extend
horizontally with their upper surfaces in a common plane and their
lower surfaces in a common plane. In the particular dock
illustrated in FIG. 3, a pair of floatation units 10 are positioned
between the joists 46 at the opposite ends thereof. A third
floatation unit 10 is positioned between one pair of short joists
48 at their outer ends and a fourth floatation unit is positioned
between another pair of short joists 48 at their outer ends. The
resulting structure, as seen in plan view, is a polygon having four
long sides and four short sides with floatation units being
positioned at each of the four short sides. This arrangement gives
good balance and stability to the dock and is manufactured at a
relatively low cost.
The floatation unit 10 has been designed so that lumber of a
conventional, inexpensive size may be employed for the joists 46
and 48. The flat top wall 26 of the unit 10 is spaced above the
flange 18-22 less than the vertical height of the joists 46 and 48
and will lie closely beneath the deck 58. It will be seen that the
flange 18-22 is much closer to the flat top wall 26 than it is to
the bottom of the floatation unit. This permits the use of joists
of short vertical height in the construction of the dock framework.
While the members 46 and 48 have been characterized as joists, it
will be apparent that various braces, supports, beams, stringers or
frame members could be used as a connection between the deck 58 and
the flanges 18-22. As used herein, the word "joist" is intended to
refer generically to all such horizontal elongated members. It
should also be noted that only portions of the flange 18-22 on
opposite sides of the floatation unit 10 need be utilized to
support the joists. Accordingly, it would be possible to interrupt
or remove portions of the flange 18-22 which are not needed for
such purpose. It will be apparent, however, that the ribs 42
perform a highly desirable function in resisting downward
deflection of the flange 18-22 and contribute to the overall load
supporting capability of the unit 10.
Should the unit 10 become punctured, it is relatively easily
repaired. If made from polyethylene, it is only necessary to melt
additional polyethylene onto the puncture hole in order to reclose
the same. Any water which has leaked into the float can be emptied
through the closable or plugged hole 44. The various ribs 34, 36,
38 and 40 add substantially to the stiffness of the sheets 12 and
14 without interferring with the assembly of the floatation unit 10
to the framework of joists 46 and 48 and without materially
detracting from the buoyance of the unit.
Another form of the invention is illustrated in FIG. 5 and consists
of a raft having four parallel joists 68. The joists 68 are joined
at their opposite ends to cross members 70 while a deck 72 is
nailed to the upper edges of the joists. A pair of floatation units
10 are positioned between one pair of joists 68 at the opposite
ends thereof while a second pair of floatation units 10 are
positioned between a second pair of joists 68 at the opposite ends
thereof. The joists 68 rest on the upper surfaces of the floatation
unit flanges 18-22 and are nailed thereto from the underside of
said flanges. A motor mounting board 74 for supporting a motor 76
may, if desired, be nailed to one of the cross members 70. It will
be apparent that a purchaser of four floatation units 10 can
construct the raft of FIG. 5 with a minimal amount of lumber,
plywood and nails. The joists 68 are stabilized at their upper
edges by the deck 72 and at their lower edges by the floatation
units 10, in addition to the stabilization given thereto by the
cross members 70, which are end nailed to the joists 68.
Accordingly, the entire structure is quite rigid as well as being
very light.
* * * * *