CA1141932A

CA1141932A - Composite beam structure

Info

Publication number: CA1141932A
Application number: CA000342823A
Authority: CA
Inventors: Alfred E. Johnson
Original assignee: Dandi Products Ltd
Current assignee: Dandi Products Ltd
Priority date: 1979-12-11
Filing date: 1979-12-31
Publication date: 1983-03-01
Also published as: AU6096980A

Abstract

ABSTRACT OF THE DISCLOSURE
There is shown a composite structural member which comprises a pair of stacked wooden board-like elements arranged vertically edge to edge and a pair of wooden plank-like means arranged one on either side of the stacked boards. The plank-like means extend in the same direction as the elements. The lower edges of the plank-like means; each of which is the same thickness as the elements, are preferrably positioned in line with the lower edge of the lower element and the upper edges of the plank-like means overlap and extend upwardly beyond the edge to edge line of contact of the stacked wooden elements to a point about one-third of the way up the upper element. Elements and plank-like means are firmly attached together to produce a rigid structure member.

Description

3~

This invention relates to composite structural members. In structural members such as beams, the height (or depth) of the beam bears a direct relationship with ~he load bearing properties o the members.
Very deep beams, ~for example~ 18" in height), are not available but are desirable as building units.
The present invention seeks to provide a relatively cheap, high efficiency, structural member.
According to the present invention there is provided a composite structural member comprising a pair of stacked wooden board-like elements arranged vertically edge to edge and a pair of wooden plank-like means arranged one on either side of said stacked board-like elements, extending in ~he same direction thereas, the plank-like means overlapping and extending upwardly and downwardly beyond the edge to edge line of contact of the stacked wooden boa~d-like elements; and means to fasten said plank-like means to said elements.
In a preferred construction the lower edges of the plank-like means are substantially in line with the lower edge of the lower board.
Preferably, the upper edges of the planks overlap and extend upwardly beyond the edge to edge line of contact of the stacked wooden boards to a height approximately one-third of the height of the upper stacked board whereby to reinforce the edge to edge line o~ contact.
Conveniently, the planks and boards may have the same thickness.
The following is a description by way of example of one embodiment of the invention, reference being had to the accompanying drawings in which:
Figure l shows diagrammatically the application of a structural member in a construction appliration; and Figure 2 is an end-on detail of a composite structural member.

Turning now to the drawings, a house basement 10 has walls 11,12 and a poured concrete floor 13 set on footings 14. In order to support the floor of th~- first floor of the house which rests on a series of cross beams 15,16, there is provided centrally of the basement a floor jack 18 of conventional configuration. Resting on the floor jack on its support plate 19 there is a longitudinally extending composite structural member 20. l~e structural member 20 runs the length of the basement parallel to the walls 11 and 12. The s~ructural member 20 comprises a pair of stacked wooden board-like elements 21,22 arranged vertically edge to edge to prov~de a line of contact 23. Each of the board-like elements 21,22 may conveniently be of 9" heig}lt to produce an overall depth of 18"
for the stack.
On either side of the stacked board-like elements 21,22 are a pair of plank-like means 25,26 which are of the same thickness as the board-like elements 21,22 and extend in the same direction as the elements 21,22. The lower edges 28,29 of the plank-like means are in line with the lower edge 30 of the lower eleme~nts 22 andJ conveniently, rest on the platform 19. The structure provicled by the elements 21,22 and the plank-like means 2S,26 is held together by an~ suitable fastening means, conveniently b~ gang nail pla~es 32,33 which extend longitudinally of the board-like elements spanning the edge 23 with rows o gang nails 36,37 struck from the plates and firml~ hammered in~o the elements 21,22. The plank-like means 25,26 are fastened by, say, gluing or nailing to the elements 21,22 to provide a rigid structure. Each of the plank-like means 25,26 conveniently is the same width as the elements 21,22 to provide a symmetrical structure having load bearing edges 40,41 upon which rest the beams 15 and 16. The means 25 are 26 preferably extend about one-third of the way up the upper element 21 and this dimension accomplishes reinforcing of the edge to edge line of contact and provides the necessary rigidity of the member~ providing sufficient resistance to bending and shearing whilst providing a convenient distance between the load bearing edges 40 and 41 and the top edge of the upper element 21 to accept a compatible sized beam 15,16.
Although the structure as described shows the use of beams 15,16 it is to be understood that the member could be used in other types of construction, such as trusses; where ~he beams 15,16 could act as purlins between adjacent trusses. The beams 15,16 (or purlins) in turn act to stiffen the member 20 and the building structure itself against racking loads.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A composite structural member comprising a single pair of stacked wooden board-like elements arranged vertically edge to edge and a pair of wooden plank-like means arranged one on either side of said stacked board-like elements, extending in the same direction thereas, the plank-like means overlapping and extending upwardly and downwardly beyond the edge to edge line of contact of the stacked wooden board-like elements; and means to fasten said plank-like means to said elements.

2. A structural member as claimed in claim 1 in which the lower edges of the plank-like means are substantially in line with the lower edge of the lower board.

3. A structural member as claimed in claim 1 or claim 2 in which the upper edges of the plank-like means overlap and extend upwardly beyond the edge to edge line of contact of the stacked elements to a height approximately one-third of the height of the upper element whereby to reinforce the edge to edge line of contact.

4. A member as claimed in claim 1 or claim 2 in which the plank-like means and the elements have the same thickness.