Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~31~6~i
This invention relates to a device for holding
logs for sawing.
When logs are to be used for firewood, they
must be cut into suitable short lengths, e.g. of
the order of 300mm. In the past, logs have been
placed on a saw horse for sawing. This consists
of an open wooden framework which viewed from one
end appears as an 'X' and in use a log simply lies
on the saw horse supported by the upper 'V' of the
'X'. This supporting device has two major disadvantages:
firstly the saw horse cannot support a log which
is shorter than the length of the saw horse between
its two end frames and thus the last two cut logs
produced will be at least half the length of the
saw horse which is too long for many uses. Secondly,
the saw horse has no positive means for preventing
the logs from rotating during sawing which makes
sawing dif~icult, especially when a motor-driven
chain saw is used.
According to the invention there is provided
a device for holding a log for sawing comprising
a square- or rectangular-section post and having
fixed thereto at least two downwardly pointed spikes
for engaging a log, and a sleeve closely fitting
around and slidably mounted on the post below the
fixed spikes and carrying at least two upwardly pointed
spikes for engaging the logs at a greater distance
from the post than said fixed spikes. In use the
sleeve is positioned such that the spikes it carries
are spaced below the fixed spikes by a distance approxi-
mately equal to the thickness of the log and the
log is positioned to engage the spikes. The log
is thus held in a cantilevered fashion from the post
and the wèight of the log causes the sleeve to jam
in position on the post.
The spikes carried by the sleeve may be about
200mm from the post thus enabling the last cut log
to be sufficiently short.
-- 3
The use of at least two fixed spikes and at
least two spikes carried by the sleeve provides means
for preventing the rotation of the logs in either
direction. The spacing of the spikes in at le~st
one of these pairs is preferably from 50-70mm, more
preferably substantially 60mm.
The sleeve preferably carries the spikes via
an arm fixed to the sleeve and projecting outwardly
from the post in a direction substantially perpendicular
thereto. The spikes are preferably mounted on a
plate fixed transversely to the end of the arm.
The fixed spikes may be mounted on a plate fixed
to the top of the post. The post, sleeve, and arm
are preferably square-section steel tubes, and all
the parts are preferably connected together by welding.
The sleeve may carry further spikes for providing
additional support for a log and in the preferred
form four spikes are carried on the plate welded
to the end of the arm.
When the device is ~not in use, the sleeve remains
in position because the weight of the arm, plate
and spikes it carries causes the sleeve to turn against
the post. To avoid the danger of the sleeve sliding
down the post if the arm is accidently knocked upwardly,
a spring, such as a leaf spring, may be provided
within the sleeve to urge it lightly into a jamming
position. The pressure of the spring may be easily
overcome by raising the arm when it is desired to
move the sleeve to a new position.
The post may be held by means of a sleeve hammered
into the ground and arranged to receive the lower
end of the post or it may be provided with a base
to that the device is free standing.
In order to prevent the spikes from engaging
a log too firmly, the spikes are preferably flat
or rounded at their points and more preferably are
provided with a flat land of substantially 2mm diameter
at their ends.
-- 4 --
An embodiment o~ the invention will now be
described by way o~ example and with reference to
the accompanying drawings, in which:
Figure 1 is a perspective view of a device
for holding a log according to the invention;
Figure 2 is a view similar to Figure 1 showing
the device holding a log in use; and
Figure 3 is a cross-section on the line III-
III in Figure 1.
Referring to the drawings, a device for holding
a log for sawing comprises a post 1 having fixed
thereto a pair of downwardly pointed spikes 2. The
post is made of square-section mild steel tube of
50mm outside dimension and 4mm wall thickness. The
spikes 2 are welded to a plate 3 fixed to the top
of the post 1 by means of welding. A plate of 70xll5mm
and lOmm thickness has been found to give adequate
strength.
Slidably mounted on the post 1 below the fixed
spikes 2 is a sleeve 4 of internal dimensions slightly
larger than the external dimensions of the post 1.
For example, the sleeve may be of 60mm outside dimension
and 4mm wall thickness giving a clearance space of
lmm between the sleeve and the post. The sleeve
is suitably 75mm in length. The sleeve 4 carries
a pair of upwardly pointed spikes 5 via an arm 6
and a plate 7. Additional spikes 8 also mounted
on the plate 7 may provide further support for a
log, although these are not essential and may be
omitted as indicated by the dotted lines in Figure
1. The arm 6 is suitably formed of square-section
tube of the same dlmensions as the post 1 and 205mm
long, and the plate 7 may be 160x50mm and lOmm thick.
The spikes 5 and 8, the plate 7, the arm 6, and the
sleeve 4 are preferably all joined together by welding.
As best seen in Figure 3, the sleeve 4 is provided
with a leaf spring 9 which passes through a slot
10 in the sleeve. The spring 9 urges the top righthand
-- 5 --
side (in Fig~re 3) of the sleeve 4 away from the
post 1 so as to assist the effect of the weight of
the arm 6 in jamming the sleeve 4 in position on
the post 1.
The spikes 2, 5 and 8 are conveniently formed
of 10mm diameter mild steel rod of 40mm overall length
and provided with a conical taper over a length of
20mm from the full diameter down to 2mm diameter
so as to provide a flat circular land on the end
of 2mm dia~eter. This prevents the spikes from digging
into the logs too firmly in use which would make
the logs difficult to remove from the device. The
spacing of the spikes 2 is substantially 60mm as
is the spacings of the spikes 5. It is desirable
that at least one of these pairs of spikes should
have substantially this spacing as this has been
found to give good results in preventing rotation
of a log. The use of additional spikes 8 has been
found useful in supporting irregularly-shaped logs
and a suitable spacing between the spikes 8 is 160mm.
The post 1 may be held in position by means
of a sleeve 10 hammered into the ground. The sleeve
10 may be of square-section mild steel tube of the
same dimens~ons as the sleeve 4 but about 300mm long.
The post 1 is conveniently about 1270mm long and
when insertèd in the sleeve 10 provides a holding
device at about waist height which is convenient
for sawing logs with a chain saw. Alternatively,
the post 1 may be made somewhat shorter and provided
with a base so that it is free standing.
In use, the sleeve 4 may be positioned by raising
the arm 6 against the pressure of the spring 9 and
sliding the sleeve up or down the post 1. On releasing
the arm the sleeve remains in position through the
action of the spring 9 and the weight of the arm
6 and associated components. A log 12 may then be
lifted and placed between the spikes 2 and the spikes
S and 8 by holding the log with the end near the
3~
-- 6 --
post 1 lower than the other end. The log may then
be lowered to firmly engage the spikes as shown in
Figure 2 whereupon the additional weight of the log
on the arm 6 Eirmly jams the sleeve 4 in position.
The log is then held in cantilever fashion and may
be sawn e.g. with a chain saw, into the desired lengths.
The length of log left after the last cut may be
as short as 200mm. The spikes 2 and 5 are very effective
in preventing rotation of the 1og. For example,
if a chain saw tends to rotate the log 12 in a clockwise
direction as seen in Figure 2, the lefthand one oE
the spikes 2 and the righthand one of the spikes
5 will engage the log more firmly to prevent rotation.
Similarly, the other ones of the spikes 2 and 5 will
prevent rotation in the opposite direction.
Thus it may be seen that the invention provides
a simple and effective device for holding logs for
sawing; the device is able to support reliably logs
of any diameter from about 60mm up to the largest
log which can be handled by one man.
