U.S. patent number 3,791,082 [Application Number 05/278,548] was granted by the patent office on 1974-02-12 for ridge roof beam.
This patent grant is currently assigned to Hearin Forest Industries. Invention is credited to J. Dennis Bowling.
United States Patent |
3,791,082 |
Bowling |
February 12, 1974 |
RIDGE ROOF BEAM
Abstract
A ridge roof beam for a modular housing unit. The beam includes
an elongated plywood web and a pair of elongated wood flanges
extending adjacent and parallel to opposite edge margins of the web
and secured in face-to-face relation to one face of the web. The
web and flanges are each constructed of elongated wood sections
bonded together in end-to-end relation. Finger grooves extending
along adjacent end edges of the sections interlock to form a secure
joint therebetween.
Inventors: |
Bowling; J. Dennis
(Battleground, WA) |
Assignee: |
Hearin Forest Industries
(Beaverton, OR)
|
Family
ID: |
23065421 |
Appl.
No.: |
05/278,548 |
Filed: |
August 7, 1972 |
Current U.S.
Class: |
52/79.1; 52/848;
52/90.1; 52/592.1 |
Current CPC
Class: |
E04C
3/17 (20130101); E04C 3/14 (20130101) |
Current International
Class: |
E04C
3/17 (20060101); E04C 3/12 (20060101); E04C
3/14 (20060101); E04c 003/00 () |
Field of
Search: |
;52/729,726,730,79,90,642,92,93,593 ;287/2.92TG |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
843,330 |
|
Mar 1939 |
|
FR |
|
897,622 |
|
Jul 1949 |
|
DT |
|
111,712 |
|
Sep 1944 |
|
SW |
|
Other References
Plywood of the World, by Andrew D. Wood, pp. 423-426, published by
Johnston & Bacon Ltd., 1963, TS/870/W6..
|
Primary Examiner: Murtagh; John E.
Attorney, Agent or Firm: Kolisch, Hartwell &
Dickinson
Claims
It is claimed and desired to secure by Letters Patent:
1. A beam comprising
an elongated continuous web including a plurality of elongated
plywood web sections joined in end-to-end relation, each plywood
web section including a pair of outer veneer sheets extending fully
the length of the section with the grain of said outer veneer
sheets extending generally longitudinally of the beam, and a
plurality of interior veneer sheets therebetween, said veneer
sheets being adhesively bonded together in face-to-face relation
along glue lines between contiguous sheets, each web section having
a groove formed in an end edge thereof receiving an end edge of an
adjacent web section, with said adjacent web sections being bonded
together along said adjacent edges, and
at least a pair of elongated, laterally spaced flanges extending
adjacent and parallel to opposite longitudinal edge margins of said
web and secured to at least one face of the web, each of said
flanges including a plurality of elongated wood flange sections
joined in end-to-end relation, each flange section having a groove
formed in an end edge thereof receiving an end edge of an adjacent
flange section, with said adjacent flange sections being bonded
together along said adjacent end edges.
2. The beam of claim 1, wherein the groove in an end edge of a web
section extends lengthwise of said end edge.
3. The beam of claim 1, wherein the groove in an end edge of a
flange section extends lengthwise of said end edge.
4. The beam of claim 1, wherein the flanges are positioned on said
web with the joints between adjacent flange sections offset in a
direction longitudinally of the beam from a joint between adjacent
web sections.
5. The beam of claim 1, wherein adjacent end edges of adjacent
sections have mating complementary groove configurations.
6. The beam of claim 1, wherein the other faces of said outer
veneer sheets define outer faces for the section, and a grooved end
edge of a web section has a first surface spaced toward the
opposite end of the section from said edge, said first surface
extending inwardly from an outer face of one of the outer sheets at
a substantial angle relative to said face of the sheet and
terminating at an inner edge intermediate the faces of said outer
sheet, a second surface extending from the inner edge of the first
surface in a plane inclined at a low angle away from the outer face
of said outer sheet across a glue line between adjacent sheets to
the end edge of the section, a third surface disposed toward the
other outer veneer sheet from said second surface, said third
surface extending away from said end edge of the section in a plane
inclined at a low angle relative to the faces of the section across
another glue line in the section to an inner end spaced from said
end edge, a fourth surface extending substantially parallel to said
second surface from said inner end of the third surface to the end
edge of the section, said fourth surface intersecting said end edge
in a region intermediate the faces of the other outer veneer sheet,
and a fifth surface at the end edge of the section extending at a
substantial angle relative to the outer face of the section from
the intersection of said fourth surface with the end edge to the
outer face of said outer veneer sheet.
7. The beam of claim 1, wherein each flange section includes a pair
of veneer sheets forming opposite face plies of the section and the
grain of said sheets extends generally longitudinally of the beam,
and the flanges are adhesively bonded to the web with a face ply of
each flange section against an outer face of the web.
8. In a modular housing unit adapted to be joined together along
one of its sides with another housing unit, a ridge roof beam
extending along said side of the housing unit, said beam
comprising
an elongated continuous web including a plurality of elongated
plywood web sections joined in end-to-end relation, each plywood
web section including a pair of outer veneer sheets extending fully
the length of the section with the grain of said outer veneer
sheets extending generally longitudinally of the beam, and a
plurality of interior veneer sheets therebetween, said veneer
sheets being adhesively bonded together in face-to-face
relationship, each web section having a groove formed in an end
edge thereof receiving an end edge of an adjacent web section, with
said adjacent web sections being bonded together along said
adjacent edges, and
a pair of elongated, laterally spaced flanges extending adjacent
and parallel to opposite longitudinal edge margins of said web and
secured to one face of the web, each of said flanges including a
plurality of elongated plywood flange sections joined in end-to-end
relation, each flange section having a groove formed in an end edge
thereof receiving an end edge of an adjacent flange section, with
said adjacent flange sections being bonded together along said
adjacent end edges.
9. The housing unit of claim 8, wherein the groove in an end edge
of a web section extends lengthwise of said end edge.
10. The housing unit of claim 8, wherein the groove in and end edge
of a flange section extends lengthwise of said end edge.
11. The housing unit of claim 10, wherein each flange section
includes a pair of veneer sheets forming opposite face plies of the
flange section and the grain of said sheets extends generally
longitudinally of the beam, and the flanges are adhesively bonded
to the web with a face ply of each flange section against an outer
face of the web.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a beam, such as may be used as the ridge
roof beam of a housing unit, and more particularly to such a beam
which is constructed of multiple end-joined wood sections.
In the construction of modular housing units, which generally are
manufactured at a central location and then transported to a
desired site, it is desirable to construct the housing unit as
light in weight and at as low a cost as possible, while still
maintaining sufficient structural rigidity. A problem that has
existed in the past is the provision of a ridge roof beam extending
lengthwise of a housing unit which provides all of these desirable
characteristics, i.e., light weight, structural rigidity, and low
cost.
In the past, various types of ridge roof beams have been devised
using plywood and/or lumber. Where plywood has been used
previously, the beams generally have taken the form of a number of
plywood sheets having square cut end edges which are merely laid
together in end-to-end relation to form a long section, with a
similarly-formed section glued in face-to-face contact wtih the
first-mentioned section. The joints between adjacent sheets in the
one section had to be offset longitudinally of the beam from joints
between adjacent sheets in the other section to provide even
minimum strength for the beam. Further, such beams had to be
relatively heavy to provide sufficient span strength.
A general object of the invention is to provide a novel flanged
beam which may be used as a ridge roof beam in a modular housing
unit, which beam has excellent strength characteristics for
spanning long distances while being relatively light weight and
inexpensively constructed.
More specifically, an object is to provide a beam which has a web
constructed of a plurality of elongated plywood web sections bonded
together in end-to-end relation at finger joints along adjacent
sets of ends of the sections, and flanges secured to one face of
the web and extending adjacent and parallel to opposite
longitudinal margins of the web. The flanges may be constructed of
plywood sections bonded in end-to-end relation at finger joints
therebetween. The bonding together of sections in the beam through
finger joints produces good continuous strength throughout the
length of the beam, and the flanges secured adjacent opposite edge
margins of the web provide good load bearing strength with minimal
weight.
DRAWINGS
These and other objects and advantages will become more fully
apparent as the following description is read in conjunction with
the drawings, wherein:
FIG. 1 is a perspective view of a pair of mating, complemetary
modular housing units which may be joined together to form an
integral structure, each unit employing a ridge roof beam according
to the invention;
FIG. 2 is an enlarged perspective view of a section of a ridge roof
beam separated from its associated housing unit, with portions of
the beam broken away;
FIG. 3 is an enlarged cross-sectional view taken generally along
the line 3--3 in FIG. 2 of a finger joint between adjacent sections
in the beam;
FIG. 4 is an enlarged view taken generally along the line 4--4 in
FIG. 1; and
FIG. 5 is a view of a modified version of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, and first more specifically to FIG. 1,
at 10, 12 are illustrated generally a pair of modular housing
units. The units are illustrated spaced apart with a pair of
mating, complementary sides of the units facing each other. The
facing sides of the two units may be moved into engagement with
each other and secured together, with the combined units forming an
integral structure.
Each unit has an elongated ridge roof beam 16 extending
longitudinally along one of its sides for supporting the roof
structure of the unit. Referring to FIG. 2, where a portion of a
beam 16 is illustrated in detail, it will be seen that the beam
includes an elongated web 20 and a pair of spaced-apart elongated
flanges 22, 24. The flanges are secured, as by gluing, in
face-to-face relation to one face of the web and extend parallel to
and adjacent opposite longitudinal edge margins of the web.
Web 20 is constructed of a plurality of elongated plywood web
sections, such as those illustrated partially at 28, 30, joined
together in end-to-end relationship. Each section is illustrated as
being made of 5-ply plywood (as seen in FIG. 3), although it will
be understood that plywood of a different number of plies also may
be used. The veneer sheets which are glued together along glue
lines between their contiguous faces to form section 28 are
indicated in FIG. 3 at 28a, 28b, 28c, 28d, 28e. Veneer sheets 28a,
28e forming the outer, or opposite, face plies of the web section
are disposed with the grain thereof extending generally in a
direction longitudinally of the beam and, as is common for plywood
sheets, these face plies extend the full length of their associated
section.
Housing units as illustrated at 10, 12 may be 50 feet or more in
length and beam 16 may extend the full length of the unit. Plywood
generally is produced in sheet 8 or 10 feet in length. Thus it may
require five or more end-joined web sections to form the web for
such beam.
As is seen in the broken-away portion of FIG. 2 and in the
cross-sectional view of FIG. 3, adjacent end edges of web sections
28, 30 have mating, complementary grooves extending lengthwise of
the edges. Referring specifically to FIG. 3, each grooved end edge
provides a pair of fingers, such as those illustrated generally at
32, 34, on panel 28, extending between opposite longitudinal edge
margins of the web section and paralleling the faces of the web
section. The grooves provided between these fingers receive similar
fingers on an adjacent section.
The fingers in the end edge of a panel are formed by making a cut
along the edge of the section to produce a first surface 36a spaced
inwardly from the end edge of the section extending inwardly from
an outer face of outer sheet 28a at a substantial angle relative
thereto and terminating at an inner edge intermediate the faces of
sheet 28a. A second surface 36b extends from the inner edge of the
first surface in a plane inclined at a low angle away from the
outer surface of the sheet, across a glue line between veneer
sheets 28a, 28b, to the end edge of the section. A third surface
38c, disposed toward the other face of the section from second
surface 36b, extends away from the end edge of the section in a
plane inclined at a low angle, across the glue line between sheets
28b, 28c, to an inner end spaced from the end edge of the sheet. A
fourth surface 36d extends substantially parallel to second surface
36b from the inner end of third surface 36c to the end edge of the
section, with the fourth surface intersecting the end edge in a
region intermediate the faces of outer veneer sheet 28c. A fifth
surface 36e extends at a substantial angle relative to the outer
face of the section between fourth surface 36d and the outer face
of the veneer sheet.
The grooved end of section 30 has a configuration similar to that
described for section 28 and, in fact, may be formed with the same
cutter head. Section 30, as illustrated in FIG. 3, is merely turned
over from the position of section 28 so that their grooved ends are
complementary.
Sections 28, 30 are joined together along their adjacent grooved
edges by applying adhesive therebetween, and forcing them
longitudinally into one another with the fingers on the adjacent
edges interlocking. Heat and pressure may be applied against the
outer surfaces of the joint during curing of the adhesive to assure
that a secure bond is obtained between the sections. Surfaces 36a,
36e extending at sharp angles inwardly from the outer surfaces of
the face plies assure that there will be no splinter edges lying
along the outer faces of the sections.
Each of flanges 22, 24 as illustrated are formed of a plurality of
elongated plywood flange sections. Portions of a pair of flange
sections 38, 40 for flange 22 and portions of a pair of flange
sections 42, 44 for flange 24 are illustrated in FIG. 2. The flange
sections are joined together in end-to-end relationship through
interlocking adhesively bonded finger joints formed by grooves at
their adjacent sets of ends, similar to those described above for
the interlocking finger joints between the web sections. The
flanges have widths which are less than half the width of the web
section and are secured adjacent opposite longitudinal edge margins
of web 20. The flange sections illustrated are formed of 5-ply
plywood in which the grain in the outer veneer sheets forming
opposite face plies for each flange extends generally
longitudinally of the beam. It should be understood that the
flanges also may be formed of a plurality of elongated pieces of
lumber joined together through adhesively bonded finger joints
formed by grooves at their adjacent sets of ends, similar to those
described above joining the web sections.
The flanges are secured in face-to-face relationship with one face
of the web of the beam by being secured thereto, as by adhesive.
Although the figures herein illustrate flanges secured only to one
face of the web, it is recognized that in certain instances it may
be desirable to provide a beam having flanges secured to both of
its faces, and such is intended to be covered by this disclosure
also.
As is illustrated in FIGS. 1 and 2, the joints between adjacent
flange sections are offset in a direction longitudinally of the
beam from the joints between adjacent sections of the web. This
lends to the continuity of strength of the beam along its length.
The depth of the web and the widths of the flanges will be dictated
by the length of span and the loads to be born by the beam.
In use, a beam is supported at its opposite ends on the end walls
of a modular housing unit. Roof trusses, such as those illustrated
at 50 in FIGS. 1, 2 and 4, are secured to and extend laterally
outwardly from the beam. As illustrated in FIG. 4, an upright leg
52 of a truss is secured, as by nailing, to flanges 22, 24 of the
beam. A spacer block 54 interposed between leg 52 and web 20 of the
beam provides a solid nailing region through which nails or staples
can be driven from leg 52 into the web of the beam.
A modular housing unit with such a ridge roof beam may be placed
against an adjacent unit with the webs of the beams in face-to-face
contact. The beams may be bolted together through their flanges to
produce an integral structure.
A modified version of the invention is illustrated in FIG. 5. A
beam 16, having a web 20 and flanges 22, 24, may be strengthened,
as illustrated in FIG. 5, by securing other flanges, such as those
indicated at 58, 60, to those faces of flanges 22, 24 which face
outwardly and away from the web. Flanges 58, 60 are constructed of
multiple finger jointed and adhesively bonded together flange
sections as previously described for flanges 22, 24 and extend
continuously the length of the beam.
As illustrated in FIG. 5 also, the upright leg 52 of a truss 50 may
be secured to the face of the web opposite the face to which the
flanges are secured. This obviates the need for a block 54 between
leg 52 and web 20 as was required in FIG. 4. The beam still may be
secured, as by bolting, to an adjacent beam in a mating housing
unit.
A beam, thus constructed, is relatively inexpensive to produce, has
excellent continuous span strength, and does not add greatly to the
weight of the housing unit. For these reasons, it has proven to be
a desirable support for roof structures in modular housing
units.
While a preferred embodiment of the invention has been described
herein, it should be apparent to those skilled in the art that
variations and modifications are possible without departing from
the spirit of the invention.
* * * * *