Note: Descriptions are shown in the official language in which they were submitted.
SPRING CLIP ELEMENT
The present invention relates to spring clip
elements and assemblies including the same.
This application is a division of copending
Canadian patent application Serial No . 326 ,109 filed
April 23, 1979. The present application is directed
to pallet constructions.
Pallets constructed of steel have considerable
advantages in that they exhibit substantially constant dimen-
sion and substantially constant weight, rendering them ofconsiderable utility in high rise storage systems and
automated systems, and have considerable durability and
weather resistance.
Steel pallets are non-combustible,in contrast to
15 wood, and are lighter than wood for the same dimensions. Wood
is also disadvantageous in that it absorbs moisture and is
subject to degradation. Steel is also attractive as a
material of construction, in that it is relatively inexpensive
when compared with aluminum and plastic.
Despite these inherent advantages, steel pallets
have not come into common usage, and those steel pallets that
have been marketed have been heavy, cumbersome and time-
consuming to produce, the elements being interconnected by
welding.
Ir. accordance with the present invention, there
is provided a spring clip structure which is useful for
assembling overlying panels, especially to form pallet
constructions. Accordingly, in one aspect, the present
invention provides a one-piece sheet metal clip for attaching
two panels in overlying relation, the first panel having
a first elongated slot, the second panel having at least
one second slot having a first edge parallel to and spaced
from an edge of said second panel to define an elongated
strip of substantially constant width between the first
35 edge and the second-mentioned edge, the first and second
slots being of substantially equal length, the clip compri-
sing: a generally U shaped body taken in cross-section
at either end thereof, the body having a length substan-
tially equal to the slots; the body being defined by
:~A~
a pair of side walls joined by a bight portion at one
end thereof and each having an outwardly extending flange
which is turned inwardly at the outer end thereof to
define a pair of inwardly~facing jaw members extending
from the other ends thereof, the outwardly-extending
flange being coplanar; the jaw members being separated
by a distance less than the width of the strip in the
non-resiliently-deformed position of the clip and having
outwardly-diverging wing members extending from the free
end of the inwardly-turned flange portion in the opposite
direction to the body; the body having a cantil~vered
ramp member formed from each of the side walls and spaced
inwardly from the ends of the side walls, the ramp members
each including a first portion extending outwardly from
the bight portion to a shouIder and a second portion
extending inwardly from the shouLder towards the flanges
terminating in substantially the plane of the outwardly-
extending flanges, the distance between the shouIders
and the flanges being greater than the thickness of the
first panel; when the jaws are separated by a distance
equal to the width of the strip, the distance between
the side walls being less than the width of the first
slot and the distance between the shoulders being greater
than the width of the first slot.
The present invention, in another aspect, also
provides an assembly comprising two panels joined in
overlying relation by a one-piece stamped spring steel
clip, the first panel having a first elongated slot having
a first width adjacent the ends thereof and a second
width:at least equal to the first width between the ends,
the second panel having at least one second slot having
a first edge parallel to and spaced from an edge of or
flange portion to define an elongated strip of substantially
constant width between the first edge and the second-
mentioned edge, the first and second slots being of sub-
stantially equal length, the panels being relatively
immovable in the direction of the length of the first
slot and relatively immovable with a predetermined degree
of resilient freedom in the transverse direction, the
clip comprising: a generally U-shaped body taken in
cross-section at either end thereof, the body being of
a length generally equal to the length of the slots,
the body being defined by a pair of side walls joined
by a bight portion at one end thereof and each having
an outwardly extending flange which is turned inwardly
at the free end thereof to define a pair-of inwardly
facing jaw members extending from the other ends thereof,
the jaw members being separated by a distance less than
the width of the strip in the non-resiliently-deformed
portion of the clip, the clip being mounted to the second
panel with the strip resiliently retained between the
jaws, the body having a cantilevered ramp member formed
from each of the side walls and spaced inwardly from
the ends of the side walls, the ramp members each including
a first portion extending outwardly from the bight portion
to a shoulder and a second portion extending inwardly from the shoulder
towards the flanges, the first panel being retained between
the second portions and the flanges, the distance between
the side walls being less than the widths of the first
slot and the distance between the shoulders being greater
than the widths of the first slot when the strip is resil-
iently retained between the jaws.
The assembly of elements may comprise a pallet
structure. Pallet structures per se form the subject
of the- parent application Serial No. 326,109. The invention,
however, will be described hereinafter with particular
reference to pallet structures.
The invention is described further, by way
of illustration, with reference to the accompanying
drawings, wherein:
Figure 1 is a perspective view of a~single-
deck ~-way steel pallet construc-ted in accordance with
one embodiment of the invention of the parent application
and embodying the invention;
Figure 2 is a close-up exploded view of the
interlocking of the stringer and deck elements of the
pallet structure of Figure 1 along with details of the
structure of the interconnecting clips;
~ Jq.j~ 3
Figure 3 is a sectional view taken along line III-
III of Figure 2 .in a disassembled position;
Figure 4 is the same sectional view as Figure 3
but in an assembled position;
Figure 5 is a perspective view of a double-deck
4-way steel pallet constructed in accordance with a second
embodiment of the invention of the parent applica~i.on
and also embodying this invention;
Figure 6 is a close-up detail view of the in~er-
locking of Ihe elements of the pallet structure of Figure
5 along with details of the structure of the interlocking
clips provided in accordance with this invention;
Figure 7 is a partial sectional view of the
assembled pallet taken along line VII-VII of Figure 5; and
Figures ~, 9 and 10 are respectively perspective,
elevation and end views of the clips used in the pallet
structure of Figures 5 to 7 and provided in accordance
with the invention.
Referring first to the embodiment of Figures 1 to
4 of the drawings, a pallet 10 constructed of, preferably
light gauge, steel, preferably corrosion resistant steel,
for example, galvanized steel, includes three elongate
hollow members or stringer elements 12 and a plurality of
deck-forming elongate roll-formed elements 14 joined to the
25 upper surface 16 of the stringer elements 12 at each inter-
section thereof and spaced apart in relation to each other
and generally perpendicular to the stringer elements 12.
The deck-forming elements 14 cooperate to provide a load-
carrying deck on the top side of the pallet 10. The
stringer elements 12 may be formed by welding together
roll-formed parts.
In the illustrated embodiment, a single-deck four-
way pallet is shown but it will be clear to those skilled
in the art that the principles of construction and the
35 interlocking arrangement may be applled to other pallet
forms, including single-deck two-way, double-deck two-way,
double-deck four-way and semi-double-deck pallets, and/or
to other types of assemblies.
The numbers of strinyer elements 12 and deck-board
elements 14 in the structure of Figures 1 to 4 is also illus-
trative and the numbers may be varied as desired, depending on
the overall dimensiors of the pallet.
In addition, while the illustrated structure of
Figures 1 to 4 is described particul~rly with reference to
the pallet parts being constructed of light gauge steel by
roll-forming, the principles of construction outlined
herein may be applied to pallet parts constructed of heavy
gauge steel or any other convenient material o~ construction,
such as, aluminum, and may be formed by any other convenient
fabrication technique, such as, extrusion.
At each intersection of the strin~er elements 12
and a surface or panel o~ the deck~forming elements 14, the
stringer elements 12 are pro~ided with an elongate slot 18
or 20, formed in t~e upper surface 16 of the stringer
element.
The deck-forming elements 14 have a generally
castellated structure which includes first and second
elongate parallel coplanar elements 22 and 24 which are
joined by an integral member defining a channel 26 there-
between and including an elongate portion 28 situated in a
plane parallel to the coplanar elements 22 and 24 and
adapted to engage the upper surface 16 of the stringer
element 12 and first and second uprigh-t elements 30 and 32
integrally joining the elongate portion 28 and the coplanar
elements 22 and 24.
The deck-forming elements 14 also include integral
skirt portions 34 and 36 depending from the coplanar elements
22 and 24 respectively, generally perpendicularly thereto
at the sides of the deck-forming members 14 for a distance
substantially equal to the depth of the channel 26.
The castellated structure described and illustrated
for the deck-forming elements 14 represents a preferred
structure for steel parts owing to the ease of roll-forming
that structure. However, i desired, the deck-forming
elements 14 may have a wholly planar top surface wlth one
or more webs depending therefrom into engagement with the
surface 16 of the stringer element 12, such as is described
in U.S. Patent No. 4,077,334.
At the lower end of each skirt portion 34 and 36
are integrally-formed flanges 38 and 40 respectively, the
flanges extending the length o~ the skirt portions and being
inwardly-directed coplanarly with the elongate portion 28.
The inwardly-directed flanges 38 and 40 define panels for
engagement with the upper surface 16 of the stringer
element 12.
At each. intersection with a stringer element 12,
the panels defined by flanges 38 and 40 are provided with
an elongate slot 42 and a parallel cut-away notch 44. As
described in more detail below, the parallel cut-away notch
44 may be replaced by a second parallel elongate slot or
the slot 42 may be moved closer to the edge of the flange
38 or 40 and the cut-away notch 44 eliminated. The slot 42
and notch 44 are provided to receive portions of a unitary
clip element 46 for the purpose of mountîng the same on the
deck-forminy element 14.
As may be seen particularly from Figures 3 and 4,
the clip element 46, constructed of suitable resilient
material, preferably spring steel, has a generally U-shaped
body 48 and a pair of oppositely-facing jaws 50 located at
the upper extremities of the body 48 for gripping the
elongate metal strip 52 between the slot 42 and the cut-
away notch 44 to hold the clip element 46 to the flange
element 38 or 40. The strip 52 is of a substantially
constant width.
Arms 47 of the U-shaped body 48 converge towards
the upper end when the clip element is in its rest or non-
deformed position as seen in Figure 2, but are generally
parallel to each other when mounted to the flanges 38 and
40 to add to the resiliency of the grip mounting o~ the
clip element 46 on the deck-forming element 14.
The arms of the U-shaped bod~ 48 are each provided
with a cantilevered wing element, or ramp element, 54
which diverges outwardly ~rom the contour of the respective
body arm 47 in the direction away from the U-bend or bight
portion of the body 48 and then turns inwardly from a
shoulder 55 at an outer extremity towards the jaw flange 50.
The distance between the shoulder 55 of the ramp
element 54 and the lower surface 56 of the lower flange of
the jaw element 50 is preferably somewhat greater than the
thickness of the upper surface 16 of the stringer element
12. The d.istance betw2en the free end of the:ramp element 54 and
the surface 56 is somewhat less than the thickness of the
upper surface 16 of the stringer element 12.
As may be seen from comparison of Figures 3 and 4,
assembly of the stringer element 12 and the deck-forming
element 14 at each intersection of the pallet is achieved
by inserting the lower U-bend or bight portion of the body
member 48 of the clip mem~er 46 into the respective elongate
opening 18 or 2a in the stringer element 12, and pushing
the deck-formin~ element 14 down so that the side edges of
the opening 18 or 2a engage the wing or ramp elements 54
resiliently forcing th.em inwardly towards the remainder
of the body member 48 until the side edges of th.e opening
18 or 20 clear the shoulder p~rtion of the ramp element 54,
which then reslliently snaps back towards its original position
(,see Figure 4) preventing removal of the clip member 46
from the,respective opening 18 or 20. The wing or ramp
member 54 may be provided with a locking tab or the like to
permanently mount a stringer element to a deck member.
The interengagement of the clips 46 with the
openings 18 and 2a not only results in a sturdy assembly
but also prevents longitudinal movement of the deck-forming
elements 14 transverse to the stringer elements 12.
Further, the interengagement of the clips 46 with the slots
18 and 20 allows a predetermined degree of resilient freedom
of the dec]c element relative to the stringer element 12 in
the direction of the axis of the stringer elements 12 but
prevents such movement beyond the point when the side walls of
the slots 18 or 20 engage the body portion 48 of the clip 46.
This arrangement arises since, as may be seen in
Figure 4, the transverse distance between the side walls 47
of the clip 46, when the clip 46 is assembled to the deck
member 14, is substantially fixed while the transverse
. distance between the shoulders 55 of the ramp elements 54
,
,' . ,
,
is relatlvely resilient. Preferably, the width of the slot 18
or 20 is yreater than the distance between the side walls
47 but less than the distance between the shoulders 55.
The deck element 14 thereby is able to move transversely
S relative to stringer 12 with a certain degree o~ resilient
freedom until the side edges of slot 18 or 20 engage the
respective side wall 47 of the clip 46, at which point
further transverse movement is prevented. More preferably,
the slot 18 or 20 is only marginally wider than the distance
between the side walls 47 so that the side walls 47 engage
the slot edges and thereby contribute to overall rigidity.
This assembly is superior to other assemblies in
which panels are joined together since the deck elements 14
have a limited degree of resilient longitudinal freedom
allowing them to resiliently absor~ shock loads in that
direction to prevent fracturing and damage to the elements
while still providing a relatively rigid assembly in both
the longitudinal and transverse directions.
As may be seen in Figure 4, when the stringer
element 12 is assembled to the dec~ element 14 utilizing
the clip 46, the upper surface 16 of the stringer element
12 is retained between the inwardly-turned upper portion
58 of the ramp element 54 and the jaw elements of the clip
46.
The flexibility of the pallet structure of Figures
l to 4 permits the pallet structure to absorb vibration and
shocks and compensate for minor height and other dimensional
variations within the pallet elements and the location of
positioning of the pallets. These abilities contrast
markedly with the very rigid structure of welded units, which
are not able readily to absorb vibration and compensate for
the dimensional and positioning variations.
In addition, the use of the mechanical interlock
arrangement between the deck elements 14 and the stringer
elements 12 utilizing the clips 46 permits ready replacement
of damaged parts, which is not the case in welded structures.
Turning now to the embodiment o~ Figures 5 to 7,
there is illustrated therein a steel pallet 110 o' modified
construction with respect to the pallet lO of Figures l to
g
4 and utilizing a modified form of clip 112 when compared
with the clips 46. The structure of the clips 112 is illus-
trated in detail in Figures 8 to 10.
The pallet 110, constructed preferably of light
gauge steel, more preferably corrosion resistant steel, for
example, galvanized steel, includes three roll-formed
elongate spaced stringer elements 114, a plurality of
elongate roll-formed top deck-board elements116 located in
spaced apart relation with each other and extending trans-
versely of the stringer elements, three space~ roll-~ormed
hollow leg elements 118 depending from the stringer
elements 114 and three elongate roll-formed bottom deck-
board elements120 connected to the lower ends of the leg
elements 118.
The pallet construction 110 of Figures 5 to 7differs
from that of Figures 1 to 4 in that the welding operations and
their time-consuming character required for construction of the
stringer elements 12 of the pallet 10 are eliminated. In the
pallet 110, the component parts are held together by clips 112.
In the illustrated embodiment, a double-deck four-
way pallet is shown but it will be clear to those skilled
in the art that the principles of construction and the
interlocking arrangement may be applied to other pallet
forms, including single-deck four-way, single-deck two-way
and double-deck two-way, as well as other types of
assemblies.
The numbers of stringer elements 114, deck-board
elements 116 and 120 and hollow leg elements 118 illustra-
ted in Figures 5 to 7 are used to illustrate the principles
of construction of the pallet llOo Any desired number of
such elements may be.used, depending on the size and intended
use of the pallet.
While the illustrated structure of Figures 5 to 7
is described particularly with reference to the pallet parts
being constructed of light gauge steel by roll-forming, the
principles of construction outlined herein may be applied to
pa;let parts constructed of heavy gauge steel or other
convenient material of construction, such as, aluminum, and
:LO
may be formed by any o-ther convenient abrication technique,
such as, extrusion.
The stringer elements 114 are elongate members
having an elongate planar panel portion 122 receiving the
deck-boards 116 thereon and integral depending side wall or
skirt portions 124 defining with the underside of the panel
portion 122 a leg receiving channel 126. The side wall
portions terminate in integral outwardly-directed perpen-
dicular wall portions 128 which themselves terminate in
integral upwardly-directed perpendicular wall portions 130
extending parallel to and for the height of the skirt
portions 124, the wall portions 130 terminating in integral
inwardly-directed flange portions 132 which provide
additional bearing surfaces for the deck-fo~ning elements
116. The arrangement of integral wall portions 124, 128 and
130 and flange 132 define generally rectangularly-shaped
elongate channels at each side of the planar panel portion
122.
At each intersection of the stringer elements 114
and panel-like engaging portions of upper deck-forming
elements 116, the stringer elements 114 are provided with
transverse elongate slots 134, formed through the panel
portion 122. The slots 134 have a narrower portion 136
adjacent the longitudinal ends thereof and a wider portion
138 extending between the narrower portions 136. The purpose
of this construction will become apparent below.
Both the upper deck-board elements 116 and the
lower deck-board elements 120 have the same structure al-
though used in opposite orientations. The structure of
these elements will be described with respect to the upper
deck-board elements 116. The upper deck-board elements 116
- ha-ve a generally castellated cross-section which includes
first and second elongate coplanar elements 140 and 142
which are joined by an integral member defining a channel
144 and including an elongate portion 146 situated in a
plane parallel to the coplanar elements 140 and 142 to engage
the upper surface of the planar portion 122 and the flange
portions 132 of the stringer L14.
' ;
. . .
11
The deck-boar~ elements 116 further include first and
second upright elements 148 and 150 integrally joining the
elongate portion 146 and the coplanar portions 140 and 142.
Integral skirt portions 152 and 154 depend from the co-
5 planar elements 140 and 142 respectively, generally perpendi-
cularly thereto at the sides of the boards 116 ~ for a distance
substantially equal to the depth of the channel 144. The
skirt portions 152 and 154 are each provided with an indented
elongate groove extending the length thereof to impart strength
10 to the deck-board elements 116.
At the lower end of the skirt portions 152 and 154
are integrally-formed inwardly-directed flanges 156 and 158
respectively, which extend the length of the skirt portions
and extend coplanarly with the elongate portion 14 6 ~ The
15 inwardly-directed flanges 156 and 158 define panels for
engagement with the planar portions 122 and the flanges 132
of the stringer elements 114.
At each intersection of an upper deck-board element
or member 116 with a stringer element 114 ~ the panels defined
20 by the flanges 156 and 158 are provided with an elongate slot
160 and a parallel cut-away notch 162~ The parallel cut-away
notch 162 may be replaced by a second parallel elongate slot
or the slot 160 may be moved closer to the edge of the flange
156 or 158 and the cut-away notch 162 eliminated. The slot
25 160 and notch 162 are provided to receive por~ions of the
unitary clip structure 112 for the purposes of mounting the
same on the deck-forming element 116 (or 120)o
Each leg element 118 consists of a generally rectan-
gularly cross-sectioned member having its longer dimension
30 vertical and is roll-formed from a single metal piece so that
the ends 164 of the metal piece are very closely located to
each other, and preferably in abutting relationship. The side
walls of the leg element 118 are waisted to impart structural
strength thereto. The leg elements 118 are received in
35 abutting interference fit relationship with the channel 126
formed by the stringer elements 114, with the ends 164 being
prevented from opening by entrapment in the channel 126~
Slots 166 of the same shape and ~orm as and aligned
' with slots 134 are provided in the portion of the leg element
118 abutting the underside of the panel portion 122 to receive
the clips 112 therethrough. Slots :L68 are provided in the
lower surface of the leg element 118 of the same shape and
form as slots 166 to receive therethrough the clips 112 mount-
5 ed on lower deck~board elements 120 to assemble the lowerdeck-board elements 120 with the remainder of the pallet.
Where a single deck pallet is required, the latter
slots may be omitted. Where a two-way pallet is required,
the spaced leg elements 118 may be provided as a continuous
10 leg element extending from one extremity of the stringer
element 114 to the other.
As may be particularly seen, particularly from
Figures 8 to 10, each clip 112, constructed of suitable resi-
lient material, preferably spring steel, ha~ a generally U
15 shaped body 170 and a pair of oppositely facing jaws 172
located at the upper extremities of the body 170 for gripping
the elongate metal strip 174 of substantially constant width
located between the slot 160 and the cut-away notch 162 to
hold the clip element 112 to the flange 156 or 158.
The jaw elements 172 also include integral diverging
wing members 176 to facilitate assembly of the clip element
112 to the deck board elements 116 or 120. The arms 178 of
the U-shaped b ody 170 converge slightly towards the jaw
element end thereof when the clip element 112 is in its rest
25 or non-deformed position (see Figure 10) but are generally
parallel to each other when mounted to the flanges 156 and
158 to add to the resiliency of the grip mounting of the
clip element 112 on the deck-board 116 or 120, as may be
in Figure 7.
The arms 178 of the U-shaped body 170 are each pro-
vided with a cantilevered wing element, or ramp element 180
a transverse dimension substantially the length of the wider
portion 138 of the slot 134. The ramp element 180 diverges
outwardly from the contour of the respective body arm 178 in
35 the direction away from the U-bend or bight portion of the
body 170 and then has an inwardly turned portion 182 exten-
ding from a shoulder 184 towards the adjacent jaw 172 to
terminate in planar alignment with the lower surface of the
jaw 172, as may be seen from Figures 8 and 10. The shoulders
,
1.3
184 are spaced apart a distance greater than the transverse
dimension of the slot 134. A locking tab 186 is provided ex-
tending oppositely from the portion 182 ~or a short aistance
towards the adjacent jaw 172.
The body portion 170 has cut-awatys 180 at each longi-
tudinal extremity adjacent the bight portion thereof to assist
in location and assembly of the pallet elements. Such cut-
aways may be omitted, if desired.
The clip 112 is mounted to the deck-board member 116
10 or 120 by engaging the wing members 176 with the slot 160 and
notch 162 and pushing the clip 112 towards the flange element
156 or 158 to spread the jaw elements 172 apart until the
sides of the metal strip 174 pass the shoulder defined by the
jaw element~ 172 and the wing elements 176, whereupon the jaws
15 172 of the clip 112 snap into resilient engagement with the
opposite sides of the metal strip 174.
Assemhly of the deck-board members 116 and 120 with
clips 112 attached thereto with the remainder of the pallet is
initiated by locating, with the assistance of the cut-aways
20 188, the U-bend or bight portion of the clip 112 in the
respective aligned elongate slot 134 and 166 of the stringer
element 114 and the leg element 118 respectively, for the upper.
deck-board members 116 or into the respective openings 168
in the leg element 118 for the lower deck-board members 120.
25 The deck-board memher 116 or 120 is then pushed towards the
respective slots, so that the side edges of the wider portions
138 of the respective slots engage the wing or ramp elements
180 resiliently forcing them inwardly towards the remainder
of the body member 170 until the side edges of the openings
30 clear the shoulders 184. The ramp elements 180 then resi-
liently snap back towards the original position to prevent
removal of the clip member 112 from the respective slot. In
this assembled position, the inwardly-turned portions 182
extend into engagement with the side edges of the wider por-
35 tion 138 of the slots while the remainder of the transverselength of the body portion 178 engages the narrow portion
136 of the slots. The locking tabs 186 result in a substan-
tially permanent assembly.
~3
14
As seen in Figure 7, the clips 112 assemble the upper
deck-board member 116 w.ith the stringer element 114 ~nd the
leg member 118. The clips 112 also assemble the lower deck-
boards 120 with the leg member 118. The clips 112 used in
5 the pallet structure of Figures 5 to 7, impart rigidity and
limited resiliency characteristics to the pallet 110 similar
to those imparted by the clips 46 in the pallet 10 of Figures
1 to 4 and discussed in more detail above with respect
thereto.
The clips 112 differ from clips 46, however, in
important and beneficial respects. -Thus, the clips 112 have
divergent wing flanges or elements 176 to permit more ready
and rapid mounting of the clips 112 on the deck-board members
116 and 120 than is the case with the clips 46. Further,
15 the inwardly-directed portions 182 of the ramp elements 180
extend further inwardly than is the case for clips 46 so as
to engage the slot walls. This ramp element structure permits
both the multiple metal thicknesses associated with assembly
of the upper deck-boards 116 with the stringer elements 114
20 and the leg elements 118 and the lesser metal thickness
associated wi~h assembly of the lower deck-boards 120 with
the leg elements 118 to be accommodated, which is not the
case with clip 46.
In summary of this disclosure, the present
invention provides clip structures for utilization with
assemblies of parts which are applicable to steel pallets
and other devices. Modifications are possible within
the scope of the invention.
