[0001] This invention relates to a method of fixing sheet metal sections relative to each
other by wooden bars or boards, which latter are inserted transversely to the longitudinal
direction of the sheet metal sections into holes punched in said sections. The object
of the invention is primarily to render possible the manufacture of rail modules consisting
of horizontal ledgers comprising the sheet metal sections and vertical boards. For
utilizing the method at the manufacture of rail modules, several desires shall be
satisfied, if possible. Firstly, the method shall be economic. Furthermore, the fixing
shall be strong so as to be capable to withstand the strains arising, for example,
when children or adults cling to and climb on the rail, and the dead weight of the
rail and snow load must not cause the rail to get crooked in the course of years.
It also is desired that the rail, when so required, permits to be positioned slightly
inclined to adapt to possible slopeness of the ground. It should preferably be possible
to make this adjustment at the mounting, but it can, of course, also be imagined at
a more substantial slopeness to manufacture the rail modules angular in a corresponding
degree. Wind and weather must neither result in the rail falling to pieces.
[0002] The aforesaid objects are realized according to the invention, in that subsequent
to the insertion of the boards into the holes in the sheet metal sections and after
the boards and sheet metal sections have been aligned in the intended angles and positions,
the sheet metal section or sections pressed together against the boards, so that for
the sheet metal sections a permanent deformation is obtained, and after the removal
of the pressing force the board springs back elastically, so that section and wood
assume a pre-stress relative to each other, which fixes them one to the other.
[0003] According to a further development of the above inventive idea, which is especially
suitable particularly for rails, the sheet metal section can have a cross-section,
the outline of which resembles a house, i.e. it has two more or less vertical side
flanges and a V-shaped central portion, the point of which is directed upward. In
this way, the deformation will take place in the point of the V when the sheet metal
section is pressed together, so that the section even after the deforming pressing
operation has a similar appearance. In order to additionally improve the fixing force
against movement of the board or boards in respective holes, it may be suitable that
the edges of the hole are slightly folded inward, so that at the pressing operation
the edges are pressed into the wood, which will result in a greater or smaller local
deformation thereof. It is, of course, not necessary that the edge penetrating into
the wood is straight, but one can imagine that one or more small jags or tips project
into the hole and yield the desired extra grip. Especially when a rail is desired
to be slightly moved inclined at its final mounting, it may be suitable that the portion
of the hole edges which penetrates into the wood only consists of a shorter piece
at the centre of the hole, so that inserted boards are subjected to a more modest
counter-holding moment when the rail module is bent up to adapt to the ground slopeness.
[0004] It can, of course, also be imagined within the scope of the invention, that the afore-mentioned
section is doubled, i.e. comprises a similar "house" section facing downward and connected
directly to the upper one. This embodiment, however, when applied to rails has the
disadvantage, that water can be included in the section, unless, for example, the
lower holes in the section are dimensioned greater than required for inserting the
boards. Due to the fact, that at the method according to the invention the height
of the section, or rather the height of the side flanges has no major effect on how
good the engagement between wood and sheet metal section will be, the flange height
can be permitted to be determined entirely by the desired strength in vertical direction
(it is in this direction the rail runs risk to be subjected to the greatest strains
at climbing etc.) and at the same time the transverse dimensions of the rail can be
held restricted, thereby rendering possible a good economy, in view of the raw material
prices of to-day-.
[0005] The invention is described in greater detail in the following, with reference to
a practical embodiment thereof shown in the drawings. Fig. 1 is a perspective view
of a portion of a rail according to the invention, Fig. 2 is a sectional view of the
fixing according to the invention, and Figs. 3 and 4 show further details in the rail
shown in Fig. 1.
[0006] The rail shown in Fig. 1 comprises a horizontally positioned sheet metal section
1, of which only a short piece is shown. In the sheet metal section a wooden bar 2
has been secured by pressing, in that the sheet metal section has been clamped about
the wooden bar 2. This is shown more clearly in Fig. 2 where it can be seen how the
sheet metal section 1 when it was pressed together has been folded additionally at
the angle point 3, so that the tips or edges 4 and, respectively, 5 for the hole in
the sheet metal section, which are located on both sides of the board or wooden bar
2, have been pressed into the wood. Fig. 1 also shows a rail post assembled of two
identical sections 6 and 7. The section parts 6 and 7 include recesses of such design
that members 8 bent to V-shape can be inserted, which in their longitudinal direction
are fixed by means of recesses 9 and 10 embracing the post sections 6 and 7. When
the rail is to be mounted, the section 1 quite simply is laid on the V-shaped member
8 and fixed against being lifted off in that a sleeve 11, which prior to the mounting
had been pushed on the sheet metal section 1, is moved to abut the post, in which
position it can be fixed in any desired way,for example by some snap-in lock.
[0007] In order to hold together the post brought about by the sections 6 and 7, at the
upper end a cover can be located which extends over recesses 12 and, respectively,
13 in the upper ends of the sections. The cover may either be clasped on or snapped
over the recesses 12, 13. Alternatively the cover 14 can be mounted in the way shown
in Fig. 3, i.e. the recesses 12,13 are chooked in whereafter the post parts 5 and
7 are moved together and thereafter inserted down into, for example, an anchorage
15 in the ground of the kind shown in Fig. 4. Of course, instead of using the anchorage
15, the post can be cast in concrete in known manner, but this should generally be
a more expensive method, because of the greater amount of labour involved.
1. A method of fixing sheet metal sections and wooden bars or boards relative to each
other, which latter can be inserted transversely to the longitudinal direction of
the sheet metal sections into holes punched in the'sheet metal sections, characterized
in that after the boards have been inserted into intended holes, and after the positions
and angles of the sheet metal sections and boards relative to each other have been
aligned, the sheet metal sections are pressed together about the boards, so that the
sheet metal section after the removal of the pressing force assumes a permanent deformation
while the inserted board or boards elastically spring back, so that section and wood
permanently are pressed against each other.
2. A sheet metal section for carrying out the method according to claim 1, comprising
holes for the receiving of boards, characterized in that the sheet metal sectionbetween
the surfaces which have been pressed together has been provided with a fold to form
a nominal deformation place for the sheet metal section, which hereby assumes a uniform
appearance.
3. A sheet metal section as defined in claim 2, characterized in that one or both
of the hole edges which at the pressing together of the section are pressed against
the board are provided with tips or edges, which face toward the wood and at the pressing
together are pressed into the wood, so that a compression over permanent local deformation
thereof is obtained, in order to yield a strong longitudinal fixing of the bar in
the section.
4. A rail, characterized in that it comprises as ledgers sheet metal sections according
to any one of the claims 2-3, with vertical wooden bars inserted into the sections,
which bars have been fixed relative to the ledgers by the method defined in claim
1.
5. A rail module, comprising horizontal sheet metal sections (1) and vertical boards
or bars (2) of wood, which have been assembled in that the sections, after the bars
have been inserted into the same, have been clamped together with great force about
the'bars, so that the sheet metal sections have assumed a permanent deformation even
after the removal of the pressing force, so that the hole edges (4 and 5) in the sheet
metal section are pressed into the wood for ensuring a good fixing relative to each
other.
