How to obtain rigidity in crate construction

MISSING IMAGE

Material Information

Title:
How to obtain rigidity in crate construction
Series Title:
Technical note ;
Physical Description:
2 p. : ill. ; 21 cm.
Language:
English
Creator:
Forest Products Laboratory (U.S.)
Publisher:
Forest Products Laboratory, U.S. Forest Service
Place of Publication:
Madison, Wis
Publication Date:

Subjects

Subjects / Keywords:
Crates -- Design and construction   ( lcsh )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

Additional Physical Form:
Also available on the World Wide Web.
General Note:
Caption title.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029391412
oclc - 61103904
Classification:
lcc - TA419 .U45 no.172
System ID:
AA00024968:00001

Full Text
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T E C H N I C A L N 6 Yt-btkr* I 114
FOREST PRODUCTS LABORATORY U. S. FOREST SERVICE MADISON. WISCONSIN
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HOW TO OBTAIN RIGIDITY IN CRATE CONSTRUCTION

One of the features of a good crate is rigidity
or ability to resist weaving and skewing during trans-
portation. No method of joining the corner members of
a crate, not even the 3-way corner construction, is
sufficient alone to give rigidity to a crate. Some
kind of bracing across the faces is usually necessary.

Figure 1 shows a kind of bracing found in many
crates which are sent to the U. S Forest Products Labo-
ratory, Madison, Wisconsin, for testing. Partly because
of the amount of material used, this construction ap-
pears to be very strong. Laboratory tests h -
however, that crates so braced a !onal1
direction of the faces, and ar t w#'e apt to we've
and skew during transportation. .. -,









FIG. 1 FIG. 2 FIG. 3

Diagonal braces on six sides as shown in Figure
2 have been found to give a crate maximum rigidity for
a minimum amount of lumber. Crates so braced withstood
with considerably less distortion twice as great a
diagonal compressive force in actual tests as crates
braced as shown In Figure l.




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A combination of diagonal and parallel slat brac-
ing, as shown in Figure 3, makes the crate more rigid
than parallel bracing alone but not so rigid in all di-
rections as cross bracing on the six sides. It may be
found an advantageous construction in packing contents
which need protection on the sides and are rigid enough
themselves to withstand stresses in the direction in
which the crate is weak.

Solid sheathing on all the faces does not make
a crate so rigid as diagonal bracing, except perhaps
sheathing which is made of wide boards with tighter
joints than can usually be obtained. The crate with
ordinary sheathing might withstand as great a load,
but the distortion caused by that load would be greater
than in a crate with diagonal braces, and would ordi-
narily be great enough to allow damage to the contents.