Claims:
What is claimed is
1. A spring base comprising a plurality of spaced elongate longitudinally extending first rod-like members, a plurality of springs, one end of each of said springs being constituted as a closed loop of greater lateral extent than the spacing between associated members of said first rod-like members, upper portions of each closed loop being disposed against under surfaces of said associated members of said first rod-like members, a plurality of spaced elongate transversely extending second rod-like members, said closed loop of each of said springs being of greater lateral extent than the spacing between associated members of said second rod-like members, opposite lower portions of each closed loop being disposed against upper surfaces of said associated members of said second rod-like members, said first and second rod-like members defining an intersecting grid-like array with said springs being operatively associated with respective openings in said grid-like array, said respective openings each being defined by a respective pair of said associated members of said first rod-like members and a respective pair of said associated members of said second rod-like members, first portions of said under surfaces of said associated members of said first rod-like members being disposed against second portions of said upper surfaces of said associated members of said second rod-like members, and securing means for connecting each of said first and second portions to one another respectively at mutually intersecting positions for biasing said first rod-like members against said upper portions of each closed loop in one direction and for biasing said second rod-like members against said opposite lower portions of each closed loop in an opposite direction to monolithically wedge and restrain said closed loops of said springs against dislodgement.
2. A spring base as claimed in claim 1 wherein each of said springs is of generally helical extent.
3. A spring base as claimed in claim 2 wherein each of said springs tapers from a maximum dimension at said one end to a minimum dimension at an opposite end.
4. A spring base as claimed in claim 1 wherein each of said longitudinally and transversely extending members is constituted of thin metallic rods welded to one another at said mutually intersecting positions thereof.
5. A spring base as claimed in claim 4 wherein each of said springs has a greater thickness than the thickness of said thin metallic rods.
6. A spring base as claimed in claim 1 wherein said securing means comprises each of said first and second portions being welded to one another respectively at said mutually intersecting positions.
Description:
BACKGROUND OF THE INVENTION
The present invention relates generally to a spring base, and more particularly to its construction and method of assembly for use in bedding or other items of upholstered furniture.
As is well known, there are countless varieties of coil spring assemblies which are arranged as a spring base, such as spring bed bottoms, each having associated therewith respective methods of construction. In this respect, spring base assemblies of conventional nature generally include a plurality of equally spaced longitudinally extending metallic rods and a plurality of equally spaced transversely extending metallic rods intersecting one another in a grid-like array. Coil springs of generally helical nature and which have a tapered extent, are fastened such as by clamps, wire, or other suitable securing means of conventional variety, to the associated pairs of longitudinally and transversely extending metallic rods either manually or by machine.
Alternatively, the helical springs are secured by providing additional longitudinally and transversely extending metallic rods which are interposed between the primary longitudinally and transversely extending metallic rods and interlaced through appropriate end portions of the helical springs for fastening or otherwise securing the latter into a fixed assembly.
Still another variety of spring base assemblies utilize a feature of interlacing a helical end portion of each of the coil springs successively over and under associated pairs of longitudinally and transversely extending metallic rods. Other varieties of spring base assemblies utilize crimps or sharply defined bends in the longitudinally and transversely extending metallic rods through which extends respective portions of the coil springs for being generally interlocked therein.
As should be well understood, these conventional spring base assemblies are, therefore, somewhat complex both with regard to the required materials of construction, and the associated methods of construction, thereby, resulting in spring base assemblies which are somewhat more expensive than is necessary, and more difficult and time consuming to manufacture.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a spring base and a method of forming same, the spring base being generally monolithic in that the materials of construction are minimal, generally the same and, thus, inexpensive in nature.
It is another object of the present invention to provide a method of constructing a spring base which may be effected rapidly, effectively and reliably in a minimal number of operations.
To this end, the present invention relates generally to a spring base and method of forming same, the method comprising forming a fixed array of generally longitudinally extending spaced parallel elongate members, providing springs each having an end portion of greater lateral dimension than the spacing between the longitudinally extending members, positioning said end portion of each of the springs in spaced relation onto at least a pair of the longitudinally extending members such that the latter members contact said end portion of each of the springs commonly in one direction, and welding a plurality of pairs of transversely extending spaced parallel elongate members to and across the longitudinally extending members so as to generally intersect therewith and bias against said end portion of each of the springs commonly in an opposite direction.
BRIEF DESCRIPTION OF THE DRAWINGS
With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:
FIG. 1 is an enlarged fragmentary elevational view of a typical coil spring as associated with typical pairs of longitudinally and transversely extending metallic rods which support the coil springs pursuant to the present invention;
FIG. 2 is a vertical cross-sectional view of the structure illustrated in FIG. 1 including a lower support member;
FIG. 3 illustrates a fragmentary enlarged perspective view of the structure generally illustrated in FIG. 1;
FIGS. 4, 5 and 6 illustrate sequentially, one method pursuant to the present invention of constructing the spring base;
FIGS. 7, 8 and 9 illustrate sequentially, still a second method pursuant to the present invention of constructing the spring base; and
FIG. 10 illustrates an enlarged fragmentary plan view of a typical coil spring as arranged to provide the spring base pursuant to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1-3 and 6, the present invention relates generally to a spring base denoted generally by the reference character 20. The spring base 20 includes a plurality of longitudinally extending elongate metallic rods 22 which extend in a common plane in spaced relation and generally parallel to one another, and a plurality of transversely extending elongate metallic rods 24 which commonly overlie and intersect the longitudinal metallic rods 22 and are welded to the latter at mutually intersecting portions 26. The longitudinally and transversely extending elongate metallic rods 22 and 24 respectively are secured appropriately to a surrounding metallic rod frame 28 such as by welding at respective points of intersection therewith denoted by respective reference characters 29 generally.
As should be clear from the drawings, the longitudinally extending elongate metallic rods 22 are all generally disposed in a common plane with one another, whereas the transversely extending elongate metallic rods 24 all extend generally in a second common plane which generally overlies the plane defined by the longitudinally extending elongate metallic rods 22.
As best illustrated in FIGS. 1-3, the longitudinally and transversely extending elongate rods 22 and 24 respectively define a grid-like array having respective square-like openings defined by respective pairs of the longitudinally extending elongate rods 22 and transversely extending elongate rods 24. Associated with each of these openings in the grid-like array, are respective helical compression coil springs 30 which taper from an enlarged end portion 32 of closed loop extent to a free end portion at the opposite end thereof denoted generally by the reference character 33. The enlarged end portion 32 of closed loop extent is provided with an extreme end 34, as illustrated in FIG. 3, which is fixedly fastened or enwrapped by conventional means upon a segment of the enlarged end portion 32 so as to present a fixed generally stiff circular periphery against which biases the longitudinally extending elongate metallic rods 22 in one direction, and against which biases the transversely extending elongate metallic rods 24 in a generally opposite direction to thereby wedge and restrain the enlarged closed loop end portion 32 of each of the springs 30 against becoming dislodged from the respective openings in the grid-like array defined by the rods 22 and 24 respectively as intersecting with one another.
Accordingly, the present invention provides for a subtle geometric relationship between geometrically cooperating structure. In this respect, each of the grid-like openings defined by respective pairs of the rods 22 and 24 respectively presents a generally square-like appearance which cooperates with the generally circular appearance of the enlarged end portion of closed loop extent 32 of each of the coil springs 30. The diameter of the closed loop 32 is provided as being somewhat greater than the extent of any of the sides of the square-like appearance presented by the intersecting rods 22 and 24 respectively, yet of lesser extent than that of the diagonal extending across opposing corners of each square-like opening and defined by the mutually intersecting portions of the rods 22 and 24 respectively as welded to one another.
Thus, the closed loop presents a common peripheral portion against which biases a respective pair of the longitudinally extending rods 22 and a generally cross-sectionally opposite common peripheral portion against which biases in an opposite direction a respective pair of the transversely extending rods 24, this resulting in what may be characterized as a wedged relationship between a circular geometric figure and a square-like geometric figure, the latter which tightly restrains the generally circular geometric figure against dislodgement; namely, the circular geometric figure is restrained against rotation, lateral displacement, and axial displacement respectively relative to the square-like geometric figure in which it is wedged.
As aforementioned, each of the helical coil springs 30 terminates in a free end 33 of generally common extent and provision is contemplated for an opposing spring frame denoted by the reference character 36 and illustrated in FIG. 2, having respective spring locating crimps 38 so as to maintain each of the springs 30 in generally parallel operative relation with one another when pressure is exerted thereagainst.
Referring now to FIGS. 4-6, there is illustrated sequentially a preferred method of constructing the spring base 20 pursuant to the present invention. In this respect, the method may include the initial provision of a fixed array of longitudinally extending elongate metallic rods 22 which are fixed to a surrounding rod frame 28 such as by welding at respective intersecting locations 29, as illustrated in FIG. 4. Thereafter, as illustrated in FIG. 5, the aforementioned geometric relationship is effected by positioning the enlarged end portion of closed loop extent 32 of each of the springs 30 in generally equally spaced relationship upon the respective pairs of longitudinally extending elongate metallic rods 22 such that the rods 22 contact the closed loop 32 in one direction or generally upwardly as the latter springs rest freely thereupon or are constrained temporarily by suitable means.
Thereafter, as illustrated in FIG. 6, respective pairs of transversely extending elongate metallic rods 24 are brought downwardly across the longitudinally extending rods 22 so as to generally intersect therewith and bias against the closed loop 32 of the respective springs 30 in a generally opposite direction, the transverse and longitudinal rods 24 and 22 respectively being welded to one another at mutual points of intersection, the welding process resulting somewhat in a slight bowing of the transverse rods 24, as at 40, illustrated in FIG. 1, or in FIG. 10, the bowed portion 40 of each of the transverse rods 24 acting to bias downwardly against the enlarged end portion of the closed loop extent 32 of the respective springs 30 while the longitudinal rods 22 bias upwardly against the closed loop 32 of the springs 30 respectively.
Accordingly, the method shown sequentially in FIGS. 4-6 is effected rapidly with a use of minimal materials and a minimal number of operations, the resultant spring base 20 being generally monolithic, there being absent clamps or other fasteners from the ultimate product, the springs having a thickness somewhat greater than the rods 22 and 24 respectively for accommodating a compression load for which it is intended, the points of intersection 26 between the rods 22 and 24 respectively being welded to one another to provide an integral grid-like array in which the springs 30 are wedged.
Pursuant to an alternate method of the present invention, there is illustrated in FIGS. 7-9, sequential steps which likewise result in the spring base 20 and satisfy the related geometrical structural concept aforementioned. In this respect, the frame 28 is formed so as to be provided initially with a plurality of pairs of longitudinally extending rods 22 which are joined therewith such as by welding or the like at 29 respectively, and a plurality of transversely extending elongate metallic rods 24A, each of which rods 24A is only one rod of each of the aforementioned pairs of transverse rods 24. The rods 24A are welded to the pairs of longitudinal rods 22 at respective points of intersection 26.
Thereafter, as illustrated in FIG. 8, the enlarged end portion of closed loop extent 32 is positioned downwardly upon the pairs of longitudinally extending rods 22 so as to overlie the latter and partially underlie the already welded transverse rods 24A, freely or in a temporarily constrained manner and remain partially canted (not shown).
The other transverse rod 24B of each of the pairs of transverse rods 24, as illustrated in FIG. 9, is thereafter positioned across the longitudinally extending rods 22 generally parallel to the originally welded transverse rods 24A so as to overlie the longitudinally extending rods 22 and bias against the enlarged end portion of closed loop extent 32 of the respective springs 30, to thereby wedge the enlarged end portion 32, as the mutually intersecting portions of the transverse rods 24B and longitudinally rods 22 are welded to one another as at 26 respectively. Again, this results in a slight deformation or bowing of the pairs of transverse rods 24A and 24B upwardly relative to the longitudinally extending rods 22 respectively.
In either instance, whether the method as illustrated sequentially in FIGS. 4-6 or in FIGS. 7-9 is utilized, the result is an interlocking of two geometric structures with one another; namely a generally stiff circular or closed loop figure being monolithically wedged within a generally stiff square-like figure, the latter reenforced as by welding.
Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and is not to be construed as a limitation of the invention.