PATINS DE GLISSEMENT POUR TRAINEAU

SKID RUNNERS

Abrégé anglais

This runner is for disposable skids, pallets and
the like load-bearing platforms which are entirely made of
corrugated cardboard. It consists of an elongated tubular
member secured under the skid panel and including a top web,
a base web and two side walls. A reinforcement strip is
located within the member; this strip has a undulated shape
and a straight cross-section. It is substantially parallel
to the walls, its top and bottom edges secured to the top
and bottom webs respectively and its opposite main faces in
alternate contact with the walls and secured to the latter
at contact zones which are spaced from one another
longitudinally of the member. The strip only partially
fills the volume of the elongated member. The pitch of the
sinusoidal strip can be shortened in selected areas to
further reinforce the runner in these areas.

Revendications

10
The embodiments of the invention for which an
exclusive property or privilege is claimed, are defined as
follows:
1. A runner made of corrugated cardboard and for
skids and the like load bearing platforms comprising an
elongated hollow member which includes a base web and two
side walls spaced from each other and normal to said base
web, said side walls having coplanar top edges, a
reinforcement strip located in said member and only
partially filling the same, said strip having an undulated
shape with rounded crests and a straight cross-section
substantially parallel to said side walls, said strip having
parallel top and bottom edges, said bottom edge bearing on
said base web, said top edge of said strip being
substantially coplanar with said top edges of said side
walls, said reinforcing strip built-up of several
laminations of single face corrugated cardboard glued
together with the corrugations normal to said base web, said
rounded crests in alternate contact with said side walls and
secured to said side walls spacedly from one another
longitudinally of said member.

11
2. A runner as defined in claim 1, wherein said
member is tubular and includes a top web, the top edge of
said strip supporting said top web.
3. A runner as defined in claim 2, wherein said top
and bottom webs and said two side walls form four sides of
said tubular member, one of said sides being extended by a
flap which laps and is secured to another one of said sides.
4. A runner as defined in claim 2, wherein the
undulations forming the undulated shape of said strip have
a shortened pitch in selected areas of said member
longitudinally of the same.
5. A runner as defined in claim 2, further including
caps closing the ends of said tubular member.
6. A runner as defined in claim 1 wherein said
laminations include two outermost laminations and wherein
the face of each lamination except one outermost lamination
adheres to the corrugations of an adjacent lamination and
the face of said one outermost lamination and the
corrugations of the other outermost lamination adhere to

12
said side walls at said rounded crests.
7. A runner as defined in claim 1, wherein the
cardboard forming said member is double face corrugated
cardboard.
8. A runner as defined in claim 7, wherein the
corrugations of said laminations have a pitch and a depth of
about 3/16".

Description

CA 02238807 1998-OS-26
1
FIELD OF THE INVENTION
The present invention relates to runners for
disposable skids made of corrugated cardboard.
BACKGROUND OF THE INVENTION
It is known to provide disposable skids or pallets
which are entirely made of corrugated cardboard. The skid
panels are normally made of two laminations, each of double-
face corrugations with the corrugations of the two panels
being criss-crossed. The runners of one type of such known
skids consist simply of a stack of several flat strips of
double face corrugated cardboard which are glued together,
the top strip being glued flat to the underside of the
panel. Such runners have sufficient strength for the
specified load bearing capacity of the skid but could be
improved as to their weight and cost.
U.S. Patent No. 2,446,914 dated August 10, 1948,
inventors: Fallert and A1, entitled "Pallet Construction"
and U.S. Patent 2,957,668 dated October 25, 1960, inventors
Norquist et A1, entitled "Materials Handling Pallet and
Method of Making Pallets", describe attempts to such
improvements by forming a tubular corrugated cardboard

CA 02238807 1998-OS-26
2
runner in which is inserted a reinforcing strip made of
double face corrugations and bent in zig zag fashion to form
longitudinally spaced v shaped ribs. Such reinforcement
strips can only be formed by sharply folding and cutting
flat stock of double-face corrugated sheet which are
necessarily supplied in panels of small length.
OBJECTS OF THE INVENTION
The main object of the present invention resides
in the provision of runners for disposable skids and the
like bearing platforms in which their weight and cost are
reduced compared to conventional runners of corrugated
cardboard and of comparable strength.
Another object of the present invention resides in
the provision of runners of the character described which
are designed to be manufactured by a continuous forming,
assembling and cutting machine.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is
provided a runner for skids and the like load bearing
platforms which comprises an elongated hollow member made
of double face corrugated cardboard and including a base web

CA 02238807 1998-OS-26
3
and two side walls spaced from each other, and a
reinforcement strip built up of several single face
corrugated laminations glued to one another said strip is
located in said member and only partially fills the same,
this strip having parallel top and bottom edaes, a
sinusoidal shape and a straight cross-section substantially
parallel to the walls, and with the corrugations disposed
vertically, the strip bottom edge bearing on the base web,
the crests of the sinusoidal strip being rounded and in
alternate contact with and secured to the walls spacedly
from one another longitudinally of the member, the strip and
walls have substantially coplanar top edges.
There are preferably four such laminations, their
corrugation form C flutes, namely they have a depth and a
pitch of about 3/16 of an inch.
Preferably, the cardboard constituting the
elongated member consists of a double wall double face
corrugations.
Preferably, the member is four-sided and one side
is extended by a flap which laps and is secured to another
side. The pitch of the strip laminations can be shortened

CA 02238807 1998-OS-26
4
in designated zones to reinforce the runner at said zones.
The runners are designed to be glued to one main
face of the quadrangular panel of a skid, said panel itself
being made of two laminations of double face corrugated
cardboard glued together, the panel corrugations being cris-
crossed.
BRIEF DESCRIPTION OF THE DRAWINGS
In the annexed drawings, like reference characters
indicate like elements throughout.
Figure 1 is a perspective view of the disposable
skid fitted with runners in accordance with the invention;
Figure 2 is a top plan view of the skid;
Figure 3 is a bottom plan view of the skid;
Figure 4 is a side elevation of the same;
Figure 5 is a partial cross-section taken along
line 5-5 of Figure 4;
Figure 6 is partial cross-section taken along line
6-6 of Figure 5;
Figure 7 is partial perspective view of one corner
of the skid;
Figure 8 is partial plan section taken along line
8-8 of the runner of Figure 5;

CA 02238807 1998-OS-26
Figure 9 is a cross-section of a modified
preferred runner;
Figure 10 is a plan section taken along line 10-10
of Figure 9; and
5 Figure 11 is a perspective view of the end cap
shown in Figures 9 and 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The skid S is of the disposable type being formed
of paper products and more particularly of corrugated
cardboard. The skid shown has a top panel 10 of square or
rectangular shape and fitted with three parallel runners 12
fixed to the underface of the top panel 10 and parallel to
two parallel sides of the quadrangular panel 10.
The top panel 10 is normally made of two
laminations 11, each of double-faced, corrugations 11a, the
corrugations being criss-crossed (see Figure 7).
Each runner 12 comprises an elongated member 13 of
U-shaped cross-section providing a base web 14 and two
spaced parallel side walls 16.
A strip 18 is located within the volume defined
within the runner 12 and only partially fills said volume.
The strip 18 has a sinusoidal shape defining rounded crests

CA 02238807 1998-OS-26
6
28 and two parallel edges, namely a bottom edge 20 and a top
edge 22. The strip has a flat cross-section and is laid on
edge, bottom edge 20 and top edge 22 bearing on base web 14
and against the under side of panel 10 respectively. Strip
18 is built-up of several laminations 19 of single face
corrugated cardboard glued together. Preferably there are
two intermediate laminations sandwiched between two
outermost laminations. Each lamination is composed of a
place lamina or face 24 and of a corrugated lamina or
corrugations 26. The face 24 of anyone lamination, except
one outermost lamination, adheres to the corrugations 26 of
an adjacent lamination. The crests 28 adhere to the walls 16
spacedly from one another longitudinally of the member or
runner 12.
Preferably, the sinusoidal strip 18 has a pitch
P of about 4 inches, the inside width of the runner 12 being
about 3 to 4 inches. Preferably, corrugations 26 form
corrugations, namely they have a depth and a pitch of about
3/16 of an inch. The top edge 22 of strip 18 and the top
edges of side walls 16 are coplanar and glued to the
underside of panel 10. Alternately, the top edges of side
walls 16 can be secured to the underside of panel 10 by an
adhesive tape.

CA 02238807 1998-OS-26
7
Looking at Figure 8, it is clear that the strip
only partially fills the inside volume of runner 12 and
therefore the entire runner is made of much less cardboard
and consequently is lighter and less expensive to make than
conventional runners formed of a stack of corrugated
laminations secured flat against the underside of panel 10.
Yet, since reinforcement strip 18 is formed of several
laminations of single face corrugated cardboard glued to one
another, each lamination is flexible and can be easily bent
to the intended sinusoidal shape with rounded crests 28.
The crests provide a good contact area to be glued to side
walls 16 of runner 12. Therefore, runner 12 has a
considerable strength against flexion and also against
torsion. In fact, tests have proven that the runners of the
invention have resistance to flexion and to torsion
sufficient to resist the load and impact forces which
conventional corrugated cardboard disposable skids are
designed to meet.
Instead of thick, non-corrugated cardboard as
shown in Figures 5, 7 and 8, the walls 16 are preferably
made of corrugated cardboard, more particularly of a double
wall corrugated cardboard, which is two corrugations
separated by an intermediate face and covered by two outer

CA 02238807 1998-OS-26
8
faces as shown in Figure 9.
Preferably, elongated member 13 forms a complete
four-sided tube 13a as shown in Figure 9 which includes a
base web 14a, side walls 16a and a top web 17a. Preferably,
a flap 30 extends from one side wall 16a and laps and is
secured to top web 17a. In this case, flap 30 is secured
flat to the underside of panel 10 while top edge 22 of strip
18 is secured to top web 17a.
Preferably, the ends of the members 13a are closed
by end caps 32, also made of double face corrugated
cardboard and defining a central square 34 and for side
flanges 36 which are folded and glued to the inside surface
of the members 13a. Thus, the runner 12 forms a very rigid
element and has a large gluing surface to be glued or
stapled to the top panel 10.
Figure 10 shows that the pitch P of the
undulations of reinforcing strip 18a are shortened in
selected zones of runner 12 to further reinforce said zones.
For instance, when skid S is intended to be supported, while
loaded, on a storage rack comprising rails supporting only
the middle and the two ends of runners 12, then strip 18 is
bunched in those zones. Figure 10 shows, as an example, a
runner 12 of length A in which the normal pitch Px is

CA 02238807 1998-OS-26
9
shortened to pitch P in a central zone and two end zones of
respective length A/5.3.
10
20

Dessin représentatif