Note: Descriptions are shown in the official language in which they were submitted.
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~Hull Conforming Flexible Bunk Unit for Boat Trailer~
Technical Fleld
The present invention related to boat trailers in
general, and in particular to bunk-type trailer~ ~or
transporting a variety of boats of the pleasure hoat
type.
Background Art
With an ever increasing number of different sized,
shaped and weighted boats due to the increasing
popularity of this industry, it is recognized that the
trailer must securely support the boat carried thereby,
and that the boat hull supporting elements guicXly
conform to the contour of the hull for proper
distribution of the weight of the boat and to avoid
localized stresses.
Adequate weight distribution for the massive hulls
supported by these modern tandem-type boat trailers
provides relative ease of maneuverability during
loading and launching, and steady towing
characteristics. A number of different styles of bunk :~
and roller-type boat trailer~ attempt to provide such
weight distribution by having a plurality of
longitudinally and laterally spaced areas of weight
support; one under the keel at the front, another above
the wheel axle, and another at the rear of the keel.
Although a definite improvement over past trailers, a
full line conformity of the support for maximum hull
support is not completely attained in certain instances
of hull configurations.
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~iS~Q~ Q~ the_Inven~iOn
A bo~ tr~llQr ls provlded whlcll ~upuort~ the boat
firmly along each side of the hull from front to rear
in a parallel-type configuration with the bunks
supported at a plurality of longitudinally spaced
points to allow the ~unks to flexibly conform to the
hull contour for equal weight distribution.
The trailer improvement includes a front crossbar
which is adjustably mounted near the front of thP
lo trailer for movement forwardly and rearwardly of the
trailer side frame members; a rear crossbar which also
is adjustably mounted near the rear of the trailer
~rame msmbers for fore and aft movement thereon; a pair
of elongated, parallel, transversely spaced bunk units
for engaging the boat hull; a first set of identical
bunk support units mounted in transversely spaced
relation on the front crossbar, each first support unit
mounted for vertical and lateral or ~ransverse
adjustment on the front crossbar, each first support
unit also pivotally supporting a bunk unit for rockable
movement about an axis parallel to the longitudinal
axis of the trailer; and a 8 cond set of identical bunk
support units mounted in transversely spaced relation
on the rear crossbar, each second support unit mounted
for lateral or transverse adjustment on the rear
crossbar, each second support unit also pivotally
supporting a bunk unit for rocXable movement about an
axis parallel to the longitudinal axis of the trailer.
Further, where conventional bunks are rigldly
fixed at two or three places on solid cross members or
crossbars, the instant invention provides in one
example for the ~ixin~ of each bunk at a ~ront cross
member only; the rear section of each bunk being
mounted at two longitudinally spaced points on a
bracket member which i8 attached to a pivotal rear
cross member or crossbar. The rear ~ection therefore
acts independently in supporting the heaviest portion
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of the boat, a di~tinc~ advantage in that the bunk~ are
~ree to naturally support tlle bo~t ~nd absorb sllock
that would normally transfer directly to the hull.
Still further, equal weight distribution
longitudinally of and on either side of the hull of the
boat being transported is enhanced by providing not
only a rear crossbar unit which supports the rear of
each bunk unit at longitudinally spaced supportiny
points, and which unit provides for a rocking or
pivoting of the supporting pivots about a transverse
horizontal axis, but also by providing a front crossbar
unit which supports the front of each bunk unit in
functionally the same way with the same result as the
rear crossbar unit. By this arrangement, each bunk
unit may be free to tend to flex within a vertical
plane between and amon~ up to four lon~itudinally
spaced supporting points. Thus the pressure between
the trailer and the hull of the boat is constantly
being monitored, such that if there is a change in the
ride, the support of the bunk units instantly adjust so
that the pressure remains constant~
It is an object of this invention to provide an
improved boat trailer.
It is another object o~ this invention to provide
fore and aft adjustably mounted support devices for the
laterally spaced, longitudinally extended bunk units
such that the bunk units tend to engage with and
conform to the contour of the hull their entire length.
With the front bunk support units vertically
adjustable, and with both front and rear bunk support
units supporting a bunk unit for pivotal movement about
a substantially horizontal axis running parallel to the
trailer longitudinal axis, the arrangement tends to
conform the flexible bunk unit to the boat hull in a
nesting manner for maximum hull support, ensuring equal
weight distribution.
It is still another object of this invention to
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provide support for laterally spaced, parallel and
longltud~nally extellded bunk un1t~ wllereby the bunk
units may flex between two or more ~upporting points,
and with one or more pairs of supporting point~ capable
of rocking in tandem about a transverse, normally
horizontal axis relative to the trailer.
In a modification, with both front and rear bunk
support units pivotal or xockable about a ~ubstantial
horizontal axis transverse the trailer longitudinal
axis, and with each bunk support unit providing a pair
of longitudinally spaced supporting points for the bunk
unit supported thereby, whereby the bunk unit is free
to t~nd to flex between and about the supporting points
in a vertical plane, again the arrangement tends to
quickly conform the flexible bunk units to the boat
hull under all conditions of the ridel thus ensuring
equal weight distribution all along both sides of the
hull.
Another object of this invention is to provide a
supporting unit for one of the boat trailer bunk units,
wherein the supporting unit is pivotal about a normally
horizontal axis transverse of the trailer, and further
wherein the bunk unit is free to tend to flex in a
vertical plane relative to the supporting unit.
Yet another object of this invention is the
provision of a bunk supporting unit including a
mounting bracket adapted to 6upport a bunk supporting
channel in either a stationary or a pivoting manner to
accommodate either a stationary or pivoting cross
member.
Brief Description of the Drawings
These and other attributes of the lnvention will
become more clear upon a thorough study of the
following description of a preferred embodiment of the
3S invention, particularly when reviewed in co~ unction
with the accompanying drawings, wherein:
Fig. 1 is a perspective view of a boat trailer of
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the present invention;
Fig. 2 i~ a plan view of the boat tra~ler of Fig.
l;
Fig. 3 is a ~ide elevational view of the boat
trailer of Fig. 1 as taken ~rom the right side thereof;
Fig. 4 is an enlarged fragmentary, sectional view
taken along the line 4-4 in Fig. 2;
Fig. 6 is a fragmentary, sectional view taken
along the line 6-6 in Fig. 2;
Fig. 7 is a sectional view taken along the line 7-
7 in Fig. 6;
Fig. 8 is a perspective exploded view of a
modified bunk supporting unit;
Fig. 9 is a fragmentary sectional view similar to
the view of Fig. 6, showing the modification o~ Fig. 8
in place at the rear of the boat trailer;
Fig. ~0 is a sectional view taken along the line
10-10 in Fig. 9; and
Fig. 11 is a fragmentary sectional view of the
Fig. 8 modification in place at the front of the boat
trailer.
Best Mode for Carryinq out the Invention
This is a continuation-in-part of my co-pending
application Serial No. 07/447,675, filed Decem~er 8,
l9B9, entitled Hull Conforming Bunk Unit for Boat
Trailer.
Although not intended to be so limited, for
convenience of illustration the improved boat trailer
bunk mounting system of this invention is shown in
connection with a trailer for loading and supporting a
low or shallow draft-type boat. The illustrated
trailer construction enables the boat to be loaded
directly ~rom the water by backing the ~railer down a
ramp or incline and bringing the rearmost hull engaging
bunk assemblies o~ the trailer into position close to
the floating boat. The boat is then advanced into
contact with the bunk assemblies and drawn forward into
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supporting engagement therewith and with the forward
keel ~upporting structur~ for full engagemellt and
support of the boat for purposes of transportation.
Referrin~ now to the drawings, particularly Fig.
1, the boat trailer of this invention is illustrated
generally at (lo) and comprises a frame assembly (11~
including a tongue (12) and hitch ~13) for conventio~al
attachment to a prime mover (not shown); a winch
assembly (14) for detachable connection to a boat (not
shown) to be transported thereby; a stand assembly (16)
for supporting the frame assembly (11) in a horizontal
condition; a front keel supporting assembly (17)
pivotally mounted on a front crossbar assembly (18); a
wheel and axle unit (19) for supporting the frame
assembly (11) adjacent the rear end thereof; a rear
crossbar assembly (21) pivotally connected to the frame
assembly (11); a pair of bunk units (22) and (23) each
secured in transversely spaced, parallel relation to
the front and rear crossbar assemblies (18) and (21);
and a pair of guide members (24), (26) for guiding the
boat to be transported by the trailer (10) onto and off
of the trailer ~10).
Let it be noted that the frame assembly (11) has
an A-shape with converged portions of the frame
assembly (11) forming the tongue (12), and with
outwardly diverging frame members (27) and (28)
including the fore part of the frame assembly (11),
with parallel and rearwardly extending frame members
(29) and (31), completing the frame assembly (11), the
rear frame members (29) and (31) extsnded parallel each
other and to the longitudinal axis of the frame
assembly (11). The rear crossbar assembly ~21)
comprises a slightly V-shaped crossbar (32) whi~h has a
pair of brackets (33), ~3~) connected at each outer end
thereof for plvotal mountlng to the respectlve rear
frame members (29), ~31).
The improvement comprises a front crossbar (36) of
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the a~embly (1~), which cro~sbar (36) 1~ ~ecured to
and extended transversely between the frame members
(29), (31) forwardly of the wheel and axle unit (19);
the rear crossbar (32) secured to and extended
transversely between the frame members (29), (31)
rearwardly of the wheel and axle unit (19); the bunk
units ~22), (23) which are disposed parallel the
longitudinal axis of the trailer (lO); a first set of
identical bunk support units (37), (3~) mounted in
transversely spaced relation on the front crossbar
(36), each bunk support unit (37), (38) adjustable
vertically and laterally on the front crossbar (36),
and pivotally supporting forward portions of one of the
bunk units (22), (23) for rockable movement about an
axis parallel the trailer (10) longitudinal axis; a
second set of identical bunk support units (39'), (41')
(Figs. 6 and 7) mounted in transversely spacPd relation
on the rear crossbar (32), each second bunk unit (39~),
~41') adjustable laterally on the rear crossbar (32)
and pivotally supporting rearward portions of one of
the bunk units (22), (23) for rockable movement about
an axis longitudinally aligned with the pivotal axis of
ona of the first bunk units and also with the trailer
longitudinal axis.
Referring to the drawings, the front crossbar
assembly (18) comprises the front crossbar (36) the
outer ends of which are welded to C-shaped brackets
(42) (Fig. 4) adjustably engaged with the respective
side frame member (29) and (31), bolt units (43)
inserted through alignable openings (not shown~ formed
in each bracket (42) and formed in longitudinally
spaced relation along each frame member (29), (31) for
longitudinal adjustability of the front crossbar
assembly (18) relative to the trailer (10).
The rear crossbar a~sembly (21) a~ ment~oned
hereinbefore includes a pair of brackets (33~, (34) at
the outer ends of the crossbar ~32) (Fig. 7), and again
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by the provision of a bolt unit (44) and approprlate
allgnable openlngs (not ~hown) formed ln the brackets
(33), (34) and the rear portions 3g th~ frame members
(29), (31), the rear crossbar assembly is also
longitudinally movable from one fastened position to
another on the frame members (29), (31), the rear
crossbar assembly is also longitudinally movable from
one fastened position to another on the frame members
~29~, (31).
lo Each bunk unit (22), (23) is identical, comprising
an elongated, flexible member (46) (Fig. 4) of wood or
like material, covered by a durable padded element (47)
for hull protection.
As the first bunk support units (37), (38) are
identical, only one (37) (Fig. 4) will be described.
This unit (37) comprises an elongated U-shaped element
(48) having a base portion (49) with longitudinally
spaced openings (51) formed therein, and with the basa
portion (49) having a top end (52) with a flat surface.
By the provision of a pair of fastening units (53)
adapted to engage spaced ones of the openings (51), the
element (48) is vertically, adjustably mounted on the
front crossbar ~36), as well as being transversely
adjusta~le thereon to accommodate the various sized and
contoured boat hulls.
Each first bunk unit support (37) also comprises
an L-shaped second element (54) (Fig. 4) having a flat
base (56) with upstanding legs (57) at each end, and
with a depending portion (58) at one side of the base
(56). As seen in Figs. 4 and~5/ the legs (57) embracP
and are secured to a bunk unit (22) by a fastener (59),
and the portion (58) is pivotally connected by another
fastener (61) along a normally horizontal axis parallel
the longitudinal axis of the trailer (10), and with ~he
bottom surface of the base ~563 spaced above the upper
surface of the first element top end (5Z). By this
arrangement, the upper element (54) and the attached
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bunk unit t22) can rock about an axi~ parallel the
tra~ler longitudlnal axis.
With the second bunk support unit~; ( 3 9 ' ), ( 4 1 ' )
~41' not being 6hown~ being identical, only the unit
5 (39') (Figs. 6, 7) will be described.
Unit (39') comprises an elongated tubular mPmber
(62'), square shaped in cross section and connected as
by welding to a plate ( 63 ' ) secured in turn to the
crossbar (32) by U-clamps (64~) for lateral adjustment
thereon.
At each end of the member (62'), an L-shaped
element (82) is provided, one depending leg (~3)
pivotally secured by a fastener (84) to an end (85) of
the element (82), and another leg (86~ secured to the
base of the bunk member (46) in a spaced rela~ion to
the upper surface (87) of the member t62~), as by
upturned projections (88) secured to the sides of the
bunk uni~ (22) by fasteners (89). The bunk support
unit (39') permits the bunk unit (21) to rock about an
axis parallel the trailer longitudinal axis and in line
with the front bunk support units (37), (38).
A modified second bunk support unit (91) (Figs. 8-
ll) is provided as a substitute for both the front bunk
support units (37), (38) and the rear bunk support
units (39'), (41') in a manner hereinafter described.
The support unit (91) comprises a V-shaped channel
(90) (Fig. 8~ having a base (92) with a pair of
longitudinally spaced openings (93), (94) formed
therein and a pair of upstanditlg legs (96), (97) each
having ~hree pair of vertically spaced holes (98)/ (99)
and (101) formed therein, each pair of holes in each
leg transversely aligned with an opposite pair of holes
as best illustrated in Fig. 8.
The support unit (91) also comprises an elongated
bracket unit (102) ~Flg. 8), having a U-~haped bracket
(103), including a top (104), sides (106~, (107) and
inwardly extended flanges ~108); a splice ~109) secured
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centrally to the bracket ~103) across ~he flange~
~108); a plate (111) secured ad~acellt one end of the
bracket (103) also across the f langes ~ 10~ ); and a pair
of end plates (112), ~113~, each with an opening (114)
formed therein, secured across each open end of the
bracket (103). Centrally of each side (106), (107) a
trio of vertically spaced pairs of holes (116), (117),
(118) are formed in transversely aligned relationship.
Figs. 9 and 10 disclose ut~lization of the
modified bunk support unit (91) for supporting a rear
portion (116) of one of the bunk units (22) similar to
the Fig. 6 arrangement. The channel (90) is mountsd on
the crossbar (32), pivotally connected to the frame
members (29~, (31) by bracket~ (33'), by its base (92~
(Fig. 9) with a U-bolt fastener (119) inserted through
the base openings (93), ~94), and whereby the support
unit (91) is adjustably mounted longitudinally on the
crossbar (32). The bracket (102~ is supported within
the upwardly open channel (90) and secured thereto by a
pair of fasteners (121) inserted through aligned pairs
of channel holes (981 and bracket side holes (11~), and
channel holes (101) and bracket side holes (118~ (Fig.
9) . .,
At each end of the bracket unit (102), an L-shaped
element (82) is provided, one depending leg (83)
pivotally secured by a fastener (84) to an end (85) of
the unit (102), and another leg (86) secured to the
base of the bunk member (46) in spaced relation to the
upper surface (87) unit (102), by upturned projections
(88) secured to the sides of the bunk unit (22) by
fasteners. In addition to the bunk support unit (91)
rocking about a substantially horizontal axis
transverse the trailer longitudinal axis, the unit (91)
also supports the bunk unit portion (116) to pivot
about a normally horizontal axis parallel the trailer
longitudinal axis, and further the bunk unit portion
(116) is free to tend to ~lex in a vertical plane
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between the supporting points formed by the elements
(82).
Fig. 11 discloses a utilization of the modified
bunk support unit (91) replacing the front bunk support
unit (37) of Figs. 4 and 5. The assembly is
substantially identical to that on the rear crossbar
(~2) of Figs. g and 10, with the exception that a
fastener (122) is inserted instead through aligned
central channel holes (99) and bracket side holes (117)
such that the bunX support unit (91) pivots or rocks
about a substantial transverse axis relative to the
boat trailer longitudinal axis via the fasteners (121),
but with the unit (91) then supporting the forward bunk
unit portion (123) in a substantially identical manner
as it supports the rear bunk unit portion (116).
