Support rail with improved spring mounting capabilities

A support rail for springs as might be used in a spring assembly such as a bedding or seat foundation. The support rails are metal and form part of a frame to which the springs are mounted. The support rails have a generally inverted U-shape and include a pair of spaced upright webs with a load carrying plate extending between and located below the upper ends. The plate is further defined by a base and side sections which curve outwardly and upwardly from the base before connecting to the upper ends of the webs. The curves of the side sections define inwardly facing receptacles located immediately below a necked area of reduced width. The support rails are utilized with springs that include at least one mounting portion shaped to snap mount into the receptacles upon downward insertion into the load carrying plate. Features are also provided to limit longitudinal movement of the springs relative to the support rails once mounted.

BACKGROUND OF THE INVENTION 
This invention generally relates to support rails used in spring assemblies 
such as bedding foundations, seat assemblies and the like and, more 
particularly, to metal support rails having improved spring mounting 
capabilities. 
Generally, a box spring assembly includes a rectangularly shaped and 
horizontally positioned frame above which is supported a mattress support 
deck. A plurality of spring modules are interposed between the frame and 
deck to support the deck. At their upper ends, the springs include deck 
attaching portions which interact with the deck so as to attach the 
springs to it. At their lower ends, prior springs have typically included 
a pair of mounting feet for attachment to the frame. A grid-like network 
of deck wires forms the deck and the grid wires which extend both 
longitudinally and transversely between a border wire. The support springs 
yieldably support the deck a predetermined distance above the frame. 
Most often, the frame itself is formed with a wood perimeter that defines 
the sides and ends of the frame. Cross rails transversely span the width 
of the frame and are formed out of either metal or wood. Depending on the 
type of cross rail, the mounting feet of the springs are secured to the 
cross rails by various methods. If the cross rail is wooden, the mounting 
feet of the springs are generally stapled in place on the cross rail. If 
the cross rail is constructed from metal, each mounting foot is typically 
provided with a U-shaped horizontal wire portion that is transversely 
inserted into a slot defined in the cross rail. 
While most formed wire springs have had two opposed yieldable portions, 
each with a mounting foot at its lower end, newer varieties of the formed 
wire springs have been constructed with only a single mounting foot 
integrally formed with both of the yieldable portions. One such spring is 
disclosed in U.S. Pat. No. 5,176,367. This patent is commonly assigned to 
the assignee of the present application. These springs, however, do not 
readily lend themselves to mounting with metal cross rails. As is evident 
from the '367 patent, that design is easily and efficiently mounted to a 
frame having wooden cross rails through the use of staples. This mounting 
method has proven satisfactory but, obviously, it is not feasible with 
metal cross rails which are often desired because of their increased 
rigidity. 
One current trend in the industry is to minimize the amount of assembly 
required by the end manufacturer while still maximizing space during the 
shipping of components to that facility. A further trend is to decrease 
the number of fasteners and variety of springs utilized in the assembly. 
In the '367 patent mentioned above, the springs are capable of being 
mounted to the support deck without fasteners and prior to shipping to the 
final assembler. Shipping is maximized because the specific construction 
of the springs was designed so that the deck/spring combination could be 
stacked and nested within similar deck/spring combinations. One principal 
element which permits the stacking and nesting of the deck/spring 
combinations is the V-shape of the springs themselves. This is not readily 
achievable when the springs have mounting feet on the lower ends of each 
yieldable section. The present invention, however, can be utilized with 
either variety of spring. 
SUMMARY OF THE INVENTION 
The springs utilized in the present invention are generally V-shaped and 
include a pair of downwardly extending yieldable sections. The upper ends 
of the yieldable sections each include a mounting bar which mounts the 
springs to the deck. The lower ends of the yieldable portions are 
unitarily formed with a mounting portion. The mounting portion is provided 
in a configuration which interacts with the frame so as to allow the 
spring to be snap mounted into the cross rails of the frame. 
The frame, as suggested above, is rectangular in shape and includes a 
wooden perimeter which defines its sides and ends. Extending transversely 
between the sides of the frame are metal support or cross rails. The 
location of the springs coincides with that of the cross rails and the 
rails support and locate the springs by engaging the mounting portions. 
More specifically, each cross rail exhibits a generally inverted U-shape 
which includes a pair of spaced apart upright sides or webs. A load 
carrying plate extends between the webs and is located at a position below 
the upper ends of the webs. Extending outward from the lower ends of the 
webs are mounting flanges that facilitate the mounting of the cross rails 
to the sides of the frame. The load carrying plate includes base and side 
support sections which extend upward and connect with the upper end of the 
webs. Proceeding from the base, the side support sections curve outwardly 
then inwardly to form opposed receptacles or grooves. When formed in this 
manner, the side sections exhibit an inwardly curved or directed portion 
which is herein referred to as a side bead. 
The configuration of cross rails and the shape of the springs are such that 
the mounting portions of the springs are biased and retained in the 
receptacles formed in the side support sections of the cross rails. In 
order to mount the support springs to the cross rails, one only needs to 
locate the support spring at the appropriate position along the length of 
the cross rail and push firmly downward until the spring "snaps" into 
place. 
The cross rail is formed with a retaining feature. This retaining feature 
ensures that once the spring is mounted on the cross rail it remains 
mounted at the desired location for proper functioning of the assembly. 
The combination of the springs "snap" mounting into the cross rails of the 
frame and the interlocking of the springs with the deck allows the springs 
to be completely mounted in the assembly without the use of any fasteners. 
This minimizes the number of components associated with the box spring 
assembly thereby reducing cost and complexity. In addition, a nestable and 
stackable deck/spring combination can now be utilized with frames having 
cross rails according to the present invention further saving assembly and 
shipping costs. 
It is an object of the present invention to provide a box spring assembly 
having metal cross rails. 
It is also an object of this invention to provide a mechanism by which 
springs can be mounted to metal cross rails. 
It is a further object of the present invention to provide a spring 
assembly in which the mounting feet of springs are mounted to cross rails 
of the frame without the use of clips or other fasteners. 
An object of this invention is also to provide a system where the spring is 
easily snap mounted into the cross rail. 
An additional object of this invention is to provide a mounting system 
which allows the springs to be located at various positions along the 
length of the cross rail. 
Yet another object of the present invention is to provide a cross rail 
mounting system where the mounting feet of the springs are specifically 
located into a predetermined position along the length of the cross rail 
and positively retained in that position once mounted. 
In achieving these and other objects, the present invention provides a 
support rail for springs as might be used in a box spring assembly. While 
other uses can be envisioned, the present invention is being described 
herein only in connection with box spring assemblies. Notwithstanding 
this, the invention should not be interpreted as being limited only to 
those assemblies. 
Additional benefits and advantages of the present invention will become 
apparent to those skilled in the art to which the present invention 
relates from the subsequent description of the preferred embodiment and 
the appended claims, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, the present invention is shown incorporated 
into a box spring assembly which is partially illustrated in FIG. 1 and 
designated at 10. The box spring assembly 10 is generally made up of three 
principal components: a support deck 12, spring modules 14 and a frame 16. 
The support deck 12 (hereinafter deck 12) is yieldably supported by the 
spring modules 14 (hereinafter springs 14) a predetermined distance above 
the frame 16. The perimeter of the frame is defined by a border wire 18 
which extends substantially continuously around the support deck 12 and 
corresponds with the perimeter of the frame 16. The border wire 18 
therefore defines a pair of opposing sides and ends. Attached to the 
border wire 18 and extending between the opposing sides and ends are deck 
wires 20, some of which extend lengthwise and others of which extend cross 
wise relative to the box spring assembly 10. Together, the deck wires 20 
form a criss-crossed, grid-like network that will distribute the loads 
applied to the box spring assembly 10. For reasons more fully described 
below, if desired, at least some of the deck wires 20 are formed with 
periodic, vertical offsets 22. 
An array of springs 14 yieldably support the deck wires 20 a predetermined 
distance above the frame 16. While it will be appreciated that numerous 
different configurations for the springs 14 themselves can be employed 
with the present invention, particular utility will be had with the 
springs 14 disclosed in U.S. Pat. Nos. 5,246,210 and 5,176,367, both of 
which are referenced herein and which have been commonly assigned to the 
assignee of the present invention. Those springs are designed so they can 
be stacked with one another and include only one mounting foot 24 for 
attachment to the frame 16. It is also anticipated that non-stackable, 
formed wire springs having more than one mounting foot will find equally 
broad utility with the present invention. While the present invention is 
being illustrated and discussed with specific reference to stackable 
springs 14, it is in no way intended for the present invention to be 
interpreted as being so limited. The full range of equivalents therefore 
includes all configurations of formed wire springs having one or more 
mounting feet which are intended to engage a cross rail. 
The mounting foot 24 of springs 14 is unitarily formed with and 
interconnects the lower ends of a pair of upwardly extending yieldable 
sections 26. While the configuration of the yieldable sections 26 need not 
be specified with respect to the present invention, as seen in FIG. 1 the 
yieldable sections 26 of the illustrated springs 14 include a series of 
substantially upright portions and torsion bars. This type of spring 14 is 
known in the industry as a formed wire, limited deflection spring. The 
upper ends of the yieldable sections 26 are each unitarily formed with an 
attaching bar 28. The attaching bars 28 are configured to interact with 
the vertical offsets 22 of the deck wires 20 so as to interlock and mount 
the springs 14 to the deck 12. Preferably, the engagement of the attaching 
bars 28 with the deck wires 20 will be such that clips or other types of 
fasteners will not be required thereby allowing for quick installation and 
mounting of the springs 14 with the deck 12. 
Another feature of the deck/spring combination is that the springs 14 and 
deck 12 can be assembled together at the component manufacturer, then 
stacked with additional deck/spring combinations so that, when shipped to 
the end manufacturer, shipping space is maximized. In providing such a 
deck/spring combination, it is beneficial if the springs 14 are capable of 
nesting within one another. One method of achieving this is to have the 
springs 14 exhibit a cone or V-shape which diverges from a single mounting 
foot 24 upward toward the attaching bars 28. This allows for the nesting 
of one spring 14 within another spring 14 after they have been mounted to 
the deck 12. 
The frame 16 itself includes a perimeter which is defined by wooden side 
rails 30 and end rails 32. Extending between the side rails 30 are metal 
cross rails 34. The springs 14 are secured to the cross rails 34. 
Three embodiments of the cross rails 34 are discussed below as are two 
embodiments of the spring mounting foot 24. After reviewing the following 
discussion, it will be appreciated that numerous additional variations on 
the actual configuration of the cross rails 34 and mounting feet 24 are 
possible. All such variations are fully intended to be within the scope of 
this invention and disclosure. 
The first embodiment of the present invention is illustrated in FIG. 2. The 
cross rail 34 can generally be seen as a hat section having an inverted 
U-shape when viewed in vertical cross section. A pair of spaced apart, 
generally upright side webs 36 define the exterior sides of the cross rail 
34 and the lower ends of the webs 36 are provided with flanges 38. The 
flanges 38 extend angularly outward from the webs 36 and facilitate 
mounting of the cross rails 34 onto the side rails 30 of the frame 16. Any 
conventional method can be used to secure the cross rails 34 to the side 
rails 30 including the use of nails, screws or other fasteners 40 inserted 
through slots or holes. The upper ends of the webs 36 are interconnected 
with each other by a load carrying plate 42. 
The plate 42 itself is comprised of a pair of side support sections 44 
which extend generally downward from the upper ends of the webs 36 to a 
horizontally extending supportive base 46 which interconnects their lower 
ends. The side sections 44 curve outwardly and upwardly from the base 46 
in a general S-shaped configuration which defines oppositely located 
grooves 48 that operate as receptacles 48 for the mounting foot 24 of the 
spring 14. These grooves 48 are bounded by the base 46 on their lower 
periphery and a longitudinally extending side bead 50 on their upper 
periphery. The shape of the grooves 48 and the width of base 46 itself, 
are such that the mounting foot 24 of the spring 14 can be received and 
retained therein. Accordingly, the opposed beads 50 define a width which 
is less than that defined by the opposed grooves 48. The mounting foot 24 
itself exhibits an overall width which generally corresponds to the width 
defined by the grooves 48. Additionally, the curvature or profile of the 
grooves 48 corresponds with the exterior surface curvature or profile of 
the mounting foot 24. 
To mount the spring 14 to the cross rail 34, the mounting foot 24 of the 
spring 14 is located at the desired position along the length of the cross 
rail 34, and then pushed downward. As the mounting foot 24 is forced 
downward, the mounting foot 24 is forced through the narrow necked area 
defined by the opposed beads 50 and, upon passing through this necked 
area, the mounting foot 24 is inherently biased outwardly causing it to 
"snap" into engagement with the opposingly positioned grooves 48. 
Obviously, the precise configuration of the mounting foot 24 can vary so 
long as it inherently is biased outward and has an overall width which is 
greater than the width defined by the beads 50. More preferably, the width 
of the mounting foot 24 is about the same as the width defined by the 
opposed grooves 48. Still more preferably, the mounting foot 24 width is 
at least slightly greater than the width defined by the opposed grooves 
48. In the first embodiment, the mounting foot 24 is provided with a 
Z-shaped or zig-zag configuration. In this configuration, the mounting 
foot 24 generally includes two outside bends 52, one of which is engaged 
in each of the opposed grooves 48. 
The inherent biasing of the mounting foot 24 operates to essentially lock 
the mounting foot 24 in engagement with the load carrying plate 42. While 
this does prevent some longitudinal movement, to further prevent 
longitudinal movement of the spring 14 along the cross rail 34 and to more 
precisely locate the spring 14 at a predetermined location along the 
length of the cross rail 34 raised bosses or buttons 54 are formed in the 
base 46 of the load carrying plate 42. The buttons 54 are provided in 
pairs, as seen in FIG. 3, and preferably, each pair of buttons 54 is 
spaced apart a minimum distance which corresponds to the overall length of 
the mounting foot 24 enabling the mounting foot 24 to be received 
therebetween. In this manner, the buttons 54 will engage the longitudinal 
ends of the mounting foot 24 preventing rotational disengagement and 
providing lateral stability. 
In the second embodiment of the present invention, as seen in FIGS. 4 and 
7, the mounting rail 134 continues to exhibit a generally inverted U-shape 
and, as with the prior embodiment, a pair of upright webs 136 that 
terminate at their lower ends in outwardly angled mounting flanges 138. 
The mounting flanges 138 may be provided with slots 139 to aid in their 
mounting to the side rails 30 of the frame 16. The upper ends of the webs 
136 are unitarily connected by a load carrying plate 142 made up of side 
sections 144 and a base 146. The side sections 144 support the base 146 at 
a position beneath the upper ends of the webs 136. 
Proceeding upward from the base 146, the side sections 144 curve outwardly 
then inwardly to respectively define a pair of opposed grooves or 
receptacles 148 and an opposed pair of longitudinally extending beads 150. 
Unlike the first embodiment, in this second embodiment, the beads 150 are 
not immediately adjacent to the upper ends of the webs 136, but rather are 
located a distance, approximately half way, between the upper ends of the 
webs 136 and the base 146. The beads 150 define a narrow necked area 
relative to the width defined by the grooves 148. This again causes the 
mounting foot 124 of the spring 14 to "snap" into engagement with the 
cross rail 134 as it is pushed downwardly into the grooves 148 of the load 
carrying plate 142. The mounting foot 124 continues to exhibit an overall 
width which is greater than the width defined by the opposed beads 150. 
The overall width of the mounting foot 124 substantially corresponds to 
the width of the grooves 148, preferably being slightly greater than that 
width. 
The mounting foot 124 seen in FIG. 5 also exhibits a configuration which 
differs from the mounting foot 24 of the first embodiment. In this second 
embodiment, the mounting foot 124 exhibits three alternating outward bends 
152. Two of the bends 152 engage one of the opposed grooves 148 and the 
remaining or center bend 152 engages the opposite groove 148. 
In order to retain the spring 14 in the appropriate position along the 
length of the cross rail 134, the second embodiment utilizes a stop tab 
156 which is lanced and bent up out of the base 146 between the side 
sections 144. The tab is formed with a length that allows it to be 
positioned within the interior curve defined by the center bend 152. 
Positioned within this bend 152, the tab 156 interferingly engages the 
mounting foot 124 during longitudinal movement and prevents movement of 
any significance. 
The third embodiment of the present invention is generally illustrated in 
FIGS. 8-14. Similar to the first two embodiments, a cross rail 234 is 
formed in an inverted U-shape. The sides of the cross rail 234 are defined 
by generally upright webs 236 and mounting flanges 238 extend angularly 
outward from the lower ends of the webs 236. Slots 239 provide an area 
through which a fastener 40 can be inserted to fasten the cross rail 234 
to the side of the frame 16. 
The upper ends of the webs 236 are unitarily formed with each other and 
connected by a load carrying plate 242. Side support sections 244 of the 
plate 242 extend from the upper end of the webs 236 and terminate in a 
substantially horizontal base 246. Proceeding upward from the base 246, 
the side support sections 244 are curved outward and then curved inward to 
first define a pair of grooves 248 and then define a pair of beads 250, 
both of which respectively face one another. In a manner similar to the 
previous embodiments, the beads 250 define a necked area whose width is 
narrower than the width defined by the grooves 248. The differing widths 
permit the mounting foot 124 of a spring 14 to "snap" into engagement with 
the load carrying plate 242 as previously described. 
The third embodiment differs from the previous embodiments in that the side 
sections 244 are additionally provided with vertical beads 258 that 
intersect the longitudinal beads 250. In the preferred version of this 
embodiment, four vertical beads 258 are grouped together to interact with 
one mounting foot 124. Per group, two vertical beads 258 are positioned on 
each side section 244 and each individual bead 258 includes an upper bead 
260 and a lower bead 262. The horizontal beads 250 and vertical beads 258 
thus cooperate to define a generally cross-like structure in the side 
sections 244 as seen in FIG. 14. 
The upper beads 260 are intended to allow the assembler to easily locate 
the position of the spring 14 and to guide the spring as it is downwardly 
inserted into the load carrying plate 242. The lower beads 262 operate to 
prevent longitudinal movement of the spring 14 once mounted. Obviously, 
the invention could be practiced with less than four vertical beads 258 
per group. Additionally, all the upper beads 260 could be omitted but this 
would eliminate the guiding function and ability mentioned above. 
As seen in FIG. 9, the vertical beads 258 are located so that each pair of 
beads 258 on one side section 244 are positioned a distance apart which 
corresponds with the overall length of the mounting foot 124 adjacent to 
it. The beads 258 on one side contact the endmost portions of the outer 
two bends 152 of the mounting foot 124 while the two vertical beads 258 on 
the opposing side section 244 are spaced apart to accommodate the center 
bend 152 of the mounting foot 124 between them. 
During mounting of the spring 14 to the cross rail 234, the mounting foot 
124 is positioned on the cross rail 234 so that the two outer bends 152 
and the center bend 152 of the mounting foot 124 are each positioned 
between the appropriate pair of upper beads 260. This properly locates the 
spring 14 and guides the mounting foot 124 during downward insertion into 
the load carrying plate 242. After passing between the necked area and the 
longitudinal beads 250, the mounting foot 124 is inherently biased outward 
into its normal shape and the lower beads 262 cooperate with the bends 152 
to prevent inadvertent longitudinal movement of the spring 14. 
In all of the above described embodiments, it is possible for the mounting 
foot 124 of a spring 14 to be easily mounted with a metal cross rail 34 
without requiring the use of fasteners. The above system also provides a 
metal cross rail 34 which has the ability to accommodate and engage 
springs having a single mounting foot design. As such, the present 
invention significantly increases production while decreasing the cost 
associated with mounting the support deck 12 and springs 14 to the cross 
rails 34 of the frame 16. 
While the above description constitutes the preferred embodiment of the 
present invention, it will be appreciated that the invention is 
susceptible to modification, variation and change without departing from 
the proper scope and fair meaning of the accompanying claims.