[0001] This invention relates to a device for joining together lengths of timber and more
particularly for joining together a vertically standing wooden post, for example a
fence post, to an extension post to provide a longer vertical standing post, which
may, for example, be used to erect a higher panel fence or to support a trellis or
other structure above an existing fence, without the need to replace the existing
post by a longer post.
[0002] According to the invention a device for joining a vertically standing wooden post
to an extension post to provide a longer vertically standing post, comprises a tubular
metal sleeve, the sleeve having substantially no external projections and being open
at both ends and having a first end portion for receiving the top end of a vertically
standing wooden post and a second end portion for receiving one end of a second wooden
post portion such that the second wooden post portion extends coaxially with the post,
said first and second end portions being separated by a stop member comprising a portion
of the sleeve of restricted internal dimension preventing the post or the second post
portion from passing completely through the sleeve.
[0003] The device according to the invention may be used with wooden fence posts of any
cross section and will normally have a cross section corresponding to the section
of the post to be extended. Normally the device will be used with posts of rectangular,
and especially square cross section, in which case the sleeve will be of rectangular
section.
[0004] In order to allow a device of a given cross sectional dimension to be used on fence
posts of smaller dimensions than their nominal size, at least one of the first and
second end portions, and preferably both, have advantageously at least one internal
protrusion which can cut into or be deflected by a post being fitted into an end portion.
[0005] Any internal protrusion for this purpose is preferably an inturned axially oriented
flange portion of the wall of the sleeve.
[0006] A single inturned flange portion may be present in each end portion of the sleeve
but normally flanges will be present at at least two spaced apart locations peripherally
of the sleeve in each end portion. When the sleeve is rectangular there will normally
be at least one inturned flange portion in two adjacent walls of the sleeve, at each
end. In a preferred embodiment two flange portions will be formed in each of two adjacent
walls at each end of the sleeve.
[0007] The flange portions may be produced by forming a suitable cut in the metal wall of
the sleeve and bending the thus formed flap inwardly of the sleeve.
[0008] The stop member is preferably located substantially midway along the length of the
sleeve and may for example be produced by deforming the wall of the sleeve inwardly
without breaking the wall of the sleeve to form a ridge extending substantially perpendicular
to the axis of the sleeve at least partially around the periphery thereof. Preferably,
however, the stop member is provided by at least one tongue portion projecting inwardly
of the sleeve and having a surface or edge substantially perpendicular to the axis
of the sleeve.
[0009] A deformation forming a ridge on the internal surface of the sleeve may extend completely
around the sleeve but is preferably present on only part of the periphery, for example,
on one or two walls of a rectangular sleeve, and similarly an inturned tongue of material
may be formed on each wall of a rectangular sleeve but preferably is formed on only
one or two walls.
[0010] An inturned tongue preferably has two surfaces perpendicular to the axis of the sleeve
since it does not then matter which way up the device is used.
[0011] The invention also provides a method for vertically extending a post using a device
according to the invention.
[0012] The invention will now be described in greater detail by way of example with reference
to the drawings, in which :-
Fig. 1 shows one form of device according to the invention;
Fig. 2 shows a second form of device according to the invention;
Fig. 3 is a plan view of the device shown in Fig.2; and
Fig. 4 shows a third form of device.
[0013] Referring to Fig.1 the first form of device according to the invention comprises
a rectangular open ended sleeve 1 of mild steel. The sleeve has a first end portion
1a for receiving the top end of a vertically arranged fence post (not shown) and a
second end 1b for receiving one end of a second fence post portion thereby forming
an extended fence post. The metal of the wall of the sleeve 1 at each end 1a,1b is
cut at two locations on adjacent walls by a vertical and two horizontal cuts and the
tongue of material thus formed is turned inwardly of the sleeve to extend perpendicular
to the wall forming apertures 2 in the wall and vertically arranged inturned flanges
3. When a wooden post or a post extension portion is inserted into an end 1a,1b of
the sleeve 1 the flanges 3 will dig into the surface of the post, securely to fix
the sleeve to the post and the post extension portion.
[0014] In order to prevent the sleeve from passing too far over the post the sleeve 1 has
a stop member arranged substantially midway along its length. According to Fig.1 the
stop member is produced by forming a horizontal and two vertical cuts in two adjacent
walls of the sleeve, in the Fig.1 these walls being the same walls as have the inturned
flanges 3, and bending the resultant flap of material inwards providing openings 4
in the wall of the sleeve 1 and a downwardly inclined tongue of material 5 resisting
passage of the post or second post portion.
[0015] The arrangement shown in Fig 2 and 3 is basically the same as that shown in Fig.1
except that in this case stop member is formed by groove 6 on the surface of the sleeve
1 and a corresponding ridge 7 on the inner wall of the sleeve 1.
[0016] In the form of device shown in Fig.4, the flanges 3 are formed as described in relation
to Fig.1. but with one horizontal and one inclined cut so that the flanges 3 each
have an upper surface inclined towards an open end of the sleeve. This assists the
flanges to cut into the wood of a post or post portion being introduced into the sleeve.
Moreover, the tongues 5 extend perpendicular to the walls of the sleeve and are positioned
on the two walls that do not include flanges 3.
[0017] The device of the invention is preferably made up from two prestamped blanks welded
together along diagonally opposed edges of the sleeve.
[0018] The device of the invention may be attached first to the post portion by driving
the post portion into one end portion of the sleeve until further movement is prevented
by the end of the post portion contacting the stop member. The second post portion
with the attached device may then be postioned over the fence post and the top end
of the post be driven into the sleeve by applying a driving force to the free end
of the second post portion.
[0019] Alternatively the end of the post and one end of the second post portion may partially
inserted into respective end portions of the sleeve and a driving force applied to
the free end of the second post portion to drive the post and the post portion completely
into the sleeve until they contact the stop member.
[0020] The device can, also first be applied over the post but then care must be taken to
avoid damage to the opposite end of the sleeve while driving it over the post.
[0021] The device of the invention will be dimensioned to receive a conventional nominal
size of post, say 50 x 50 mm (2 x 2 inch) or 75 x 75 mm (3 x 3 inch). The length of
the sleeve is preferably about 2.to 2.5 times the nominal dimension of the post, say
100 to 125 mm or 150 to 180 mm.
[0022] The stop member may, for example, project inwardly approximately 6.5 mm (.25 inch)
and the inturned flanges may have a length of about 40 mm (1.5 inches) and a width
of 6.5 mm (.25 inch). The device is preferably constructed from 3 mm (.125 inch) mild
steel.
1. A device for joining a vertically standing wooden post to an extension post to
provide a longer vertically standing post, which comprises a tubular metal sleeve
the sleeve having substantially no external projections and being open at both ends
and having a first end portion for receiving the top end of a vertically standing
wooden post and a second end portion for receiving one end of a second wooden post
portion such that the second wooden post portion extends coaxially with the post,
said first and second end portions being separated by a stop member comprising a portion
of the sleeve of restricted internal dimension preventing the post or the second post
portion from passing completely through the sleeve.
2. A device according to claim 1 wherein at least one of the first and second end
portions have at least one internal protrusion in the wall thereof to compensate for
differences in the actual size of posts of given nominal dimension.
3. A device according to claim 2 wherein internal protrusions are formed in the wall
of both end portions.
4. A device according to claim 2 or claim 3 wherein the internal protrusions comprise
at least one axially oriented inturned flange portion that can cut into the fence
post and/or the second post portion when received within the respective end portion
of the device.
5. A device as claimed in any one of claims 1 to 4 wherein the sleeve is of rectangular
cross section.
6. A device according to claim 5 wherein the sleeve is of square cross section.
7. A device according to any one of claims 2 to 6 wherein internal protrusions are
formed at at least two spaced apart locations peripherally of the sleeve in one or
both end portions.
8. A device according to any one of claims 5 to 7 wherein protrusions are formed on
two adjacent walls of one or both end portions.
9. A device according to any one of claims 1 to 8 wherein the stop member is located
substantially midway along the length of the sleeve.
10. A device according to any one of claims 1 to 9, wherein the stop member is provided
by a ridge extending substantially perpendicular to the axis of the sleeve and at
least partially around the wall of the sleeve.
11. A device according to any one of claims 1 to 9, wherein the stop member is provided
by at least one tongue portion projecting inwardly of the sleeve and having a surface
or edge substantially perpendicular to the axis of the sleeve.
12. A method for vertically extending a vertically standing wooden post to produce
a longer vertically standing post wherein there is used a device according to any
one of claims 1 to 11 and comprising the steps, in any order, of fitting one end portion
of the device over the upper end of the post and the other end portion of the device
over one end of a second post portion until the ends of the post and post portion
contact the stop member.