Scarf.
1. (
Carpentry.) A joint uniting two pieces of timber endwise.
The ends of each are beveled off, and projections are sometimes made in the one corresponding to concavities in the other, or a corresponding cavity in each receives a joggle; the two are held together by bolts, and sometimes also by straps.
Also written
scarph.
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Scarfs. |
The rods for the pumps of mines are sometimes made in wooden sections joined together by scarfs and bands.
a,
Fig. 4660, is from a pump-rod in a German mine.
It is common, but not universal, to scarf the timbers together without making a bulge at the junction.
In some cases the parts are simply laid or driven together, and in others they are forced to their seats by means of a wedge.
In all cases the notches of one have counterpart projections on the other face, and the surfaces fit snugly against each other without longitudinal or lateral play.
The mode of scarfing which has the appearance of a regular zigzag, when viewed in elevation, is called by the
French,
traits de Jupiter (
i), from a fancied resemblance to forked lightning.
The timbers are secured by bolts, straps, side plates, stirrups, or other devices, according to circumstances and the nature of the strain.
Fig. 4660 illustrates various modes of scarfing.
a, pump-rod scarf
b c, scarfs with wedges and fish-plates.
d, scarf with wedge.
e, scarf without wedge.
f, another form showing the two pieces apart and united.
g h, different ways of making the joint.
i, traits
de Jupiter.
j k, end scarfs
l m n, square and bevel scarfs.
o, hook and butt.
p, square scarf with iron fish-plate.
q, bevel scarf with bolts.
r, hook butt scarf
s, scarf joint secured by fish-plates, bolts, and keys.
t, plain rabbeted scarf with bolts.
2. (
Metal-working.) The flattened or
chamfered edges of iron prepared for welding.
The two surfaces being drawn out or cut obliquely, a larger contact is given to them, which fortifies the junction.
