U.S. patent number 3,574,241 [Application Number 04/789,314] was granted by the patent office on 1971-04-13 for spring and frame assembly particularly for box springs.
This patent grant is currently assigned to Hoover Ball and Bearing Company. Invention is credited to Walter V. Slominski.
United States Patent |
3,574,241 |
Slominski |
April 13, 1971 |
SPRING AND FRAME ASSEMBLY PARTICULARLY FOR BOX SPRINGS
Abstract
A spring and frame assembly, particularly for box springs for
beds, consisting of a plurality of main springs arranged crisscross
fashion on a rectangular supporting frame and internal support
springs supported on the frame and secured to the main springs.
Each of the main springs has a resilient end portion movable
between an upwardly extending position when not loaded and a
downwardly compressed position when under load, and each of these
end portions includes a pair of generally upright spacer bars that
function to limit the magnitude of the downward movement of the
main spring when under load.
Inventors: |
Slominski; Walter V.
(Lexington, KY) |
Assignee: |
Hoover Ball and Bearing Company
(Saline, MI)
|
Family
ID: |
25147261 |
Appl.
No.: |
04/789,314 |
Filed: |
January 6, 1969 |
Current U.S.
Class: |
5/247; 5/255 |
Current CPC
Class: |
A47C
23/04 (20130101) |
Current International
Class: |
A47C
23/04 (20060101); A47C 23/00 (20060101); A47c
023/02 (); A47c 023/04 () |
Field of
Search: |
;5/247,255,246
;267/103,107 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gay; Bobby R.
Assistant Examiner: Mitchell; James C.
Claims
I claim:
1. A spring and frame assembly comprising a generally rectangular
and substantially horizontal frame, a plurality of wire springs
arranged crisscross fashion on said frame, each of said springs
including a body portion disposed in a spaced relation above said
frame and at least one resilient end portion extending between said
body portion and said frame so as to support said body portion on
said frame, said end portion including relatively inclined
connecting bars which are relatively movable to enable compression
and expansion of said end portion with a corresponding movement of
said body portion toward and away from said frame, a pair of
substantially upright spacer bars and a plurality of torsion bars
connecting to said connecting bars and said spacer bars, a pair of
said torsion bars being located at the upper ends of said spacer
bars, said spacer bars being engageable with said frame to limit
downward movement of said end portion toward said frame, and said
body portion being engageable with at least one of said pair of
said torsion bars in said end portion to limit movement of said
body portion toward said frame.
2. A spring and frame assembly according to claim 1 wherein one of
said torsion bars is disposed at the lower end of said end portion
in engagement with said frame, and a substantially L-shape
attaching foot integral with said one torsion bar, said foot
terminating in an attachment bar which is inclined with respect to
said one torsion bar.
3. A spring and frame assembly according to claim 1 wherein one of
said torsion bars in said end portion is integral with and extends
transversely of said body portion at one end thereof, said one
torsion bar being of a reduced length relative to the others of
said torsion bars.
4. A spring and frame assembly according to claim 3 wherein said
body portion is substantially straight and said spacer bars are
disposed in a spaced relation in a direction along the length of
said body portion.
5. A spring and frame assembly according to claim 4 wherein one of
said connecting bars extends downwardly and inwardly from one end
of said reduced length torsion bar, another one of said torsion
bars extends transversely from the inner end of said connecting
bar, one of said spacer bars extends downwardly from said one
torsion bar, another one of said torsion bars extends from the
lower end of said one spacer bar in a substantially parallel
relation with said one torsion bar, another one of said connecting
bars extends outwardly from said other torsion bar, and the other
one of said spacer bars extends downwardly relative to the outer
end of said other connecting bar.
6. A spring comprising a wire member shaped to form a body portion
having a substantially horizontal and substantially straight end
section and a resilient end portion which extends downwardly from
said end section, said end portion being movable between an
expanded position and a compressed position, said end portion in
said compressed position providing for movement of said end section
downwardly relative to the position thereof in said expanded
position, said end portion including upright spacer bars and
torsion bars connected to the upper ends of said spacer bars and
extending transversely of said end section at a position directly
therebelow, and connecting bars in said end portion movable
relative to each other to enable said movement of said end portion
between said positions.
7. A spring according to claim 6 wherein said end portion
terminates at the lower end thereof in a substantially horizontal
attachment bar which is inclined with respect to said torsion
bars.
8. A spring according to claim 6 wherein said end portion further
includes a torsion bar at the upper end of said end portion, one of
said connecting bars extending downwardly and inwardly from said
upper end torsion bar at an angle of about 45.degree. in said
expanded position of said end portion, one of said spacer bars
being located at the lower end of said one connecting bar, another
one of said connecting bars extending outwardly from the lower end
of said one spacer bar, and the other spacer bar being located
adjacent the outer end of said other connecting bar.
9. A spring according to claim 6 wherein said end portion torsion
bars are arranged in a vertically spaced relation with the
uppermost one of said torsion bars being of a reduced length
relative to the ones of said torsion bars therebelow and being
located at the end of said end sections.
10. A spring according to claim 9 wherein said connecting bars are
disposed in a common vertical plane and said spacer bars are
disposed in a common vertical plane spaced from the plane of said
connecting bars, said planes being located on opposite sides of
said straight end section.
11. A spring according to claim 10 wherein said end portion is
shaped so that one of said connecting bars extends downwardly and
inwardly underneath said body portion and the other connecting bar
is disposed below said one connecting bar, a pair of said torsion
bars being located at the inner ends of said connecting bars, and
one of said spacer bars being connected to and extended between
said pair of torsion bars.
Description
The conventional box spring consists of a rectangular wood frame on
which a plurality of coil springs and border wires are mounted, and
a fabric cover and pad which are positioned over the spring and the
border wires and attached to the frame. The spring and frame
assembly of this invention, which is particularly adapted for box
springs, eliminates the conventional coil springs and consists
generally of a wood frame and a plurality of substantially
identical mainsprings which extend crisscross fashion above the
frame and have depending resilient end portions secured to the
frame. Internal springs, are similarly mounted on the frame and are
secured to the mainsprings intermediate their ends for strength
purposes. In the construction of this type illustrated in
applicant's prior U.S. Pat. No. 3,286,281, abnormally high and
unusually concentrated loads on the spring assembly can result in
movement of the spring assembly to an undesirable extreme position
in which the spring assembly bottoms on the frame. In addition,
prior constructions of this type were subject to taking substantial
"set" during a prolonged service life because spring movement was
concentrated in a small number of torsion bars.
The spring and frame assembly of this invention consists of a
rectangular frame and transversely extending support members or
slats which are mounted on the frame. The resilient end portions of
the mainsprings are mounted on the frame so that they normally
maintain the spring body portions at a predetermined elevation
above the frame. When the springs are loaded, the resilient end
portions are compressible to allow the body portions to move toward
the frame. Each mainspring end portion includes a pair of generally
upright spacer bars having transversely extending torsion bars at
their upper ends. The torsion bars are located so that they extend
transversely of the body portion at a position directly below the
body portion. As a result, in the fully compressed position of the
spring end portion, the frame limits downward movement of the
spacer bars to a position in which the torsion bars at the upper
ends thereof are engageable with the spring body portion to limit
downward movement thereof. As a result, a maximum load on the
spring assembly will only deflect the spring body portions to
certain position, thus limiting the load on the spring components.
Furthermore, each spring end portion is configured such that during
deflection three of the torsion bars are moved through
substantially the same angle so that they substantially equally
divide resistance to the load. This eliminates load concentrations
in one or two torsion bars causing these torsion bars to take a
"set" thereby reducing the resiliency characteristics of the
spring.
It is an object of the present invention, therefore, to provide an
improved spring and frame assembly of the above-described type in
which the springs have limited defection capabilities and improved
resistance to loads.
Further objects, features and advantages of this invention will
become apparent from a consideration of the following description,
the appended claims, and the accompanying drawing in which:
FIG. 1 is a plan view of the spring and frame assembly of this
invention;
FIG. 2 is a perspective view of a portion of a mainspring in the
assembly of this invention;
FIG. 3 is a developed plan view of the spring portion shown in FIG.
2;
FIG. 4 is an enlarged transverse sectional view of a portion of the
spring and frame assembly of this invention, as seen from
substantially the line 4-4 in FIG. 1, showing the spring in a
partially compressed position in solid lines and in an expanded
position in broken lines;
FIG. 5 is a transverse sectional view, illustrated similarly to
FIG. 4, showing the spring in solid lines in a fully compressed
position and in broken lines in an expanded position; and
FIG. 6 is a fragmentary top view of the mainpsring of this
invention in its fully compressed position shown in FIG. 5.
With reference to the drawing, the spring and frame assembly of
this invention, indicated generally at 10, is illustrated in FIG. 1
as including a rectangular support frame 12, shown as being formed
of wood, a plurality of mainsprings 14 which extend lengthwise of
the frame 12 and a plurality of mainsprings 16 which extend
transversely of the main frame 12. A pair of end rails 18, a pair
of side rails 20, and a plurality of spring-support members or
slats 22, mounted on the rails 20, also form part of the frame 12.
A sectional border wire 24 is secured to the mainsprings 14 and 16
so that the border wire 24 is disposed above the frame rails 18 and
20. A plurality of internal support springs 26, illustrated as
being 12 in number, support intermediate portions of the
mainsprings 14 and 16 on the slats 22.
The mainsprings 14 and 16 are substantially identical, differing
only in that the springs 14 are longer than the springs 16. Each
mainspring 14 and 16 includes an elongated load-support or body
portion 28, illustrated as being a substantially straight length of
wire, and end portions 30 which are right- and left-hand versions
of each other and extend downwardly from the ends of the body
portion 28.
Each mainspring end portion 30 includes five torsion bars 32, 33,
34, 35 and 36, a connecting bar 38 which extends downwardly and
inwardly from one end of the torsion bar 32 to one end of the
torsion bar 33 in the expanded position of the end portion 30 shown
in FIG. 2, and a connecting bar 40 which extends downwardly and
outwardly from one end of the torsion bar 34 to one end of the
torsion bar 35. The connecting bars 38 and 40 are disposed in
substantially the same vertical plane, the significance of which
will appear later. The end portion 30 also includes a pair of
generally upright spacer bars 42 and 44, which are also disposed in
substantially the same vertical plane spaced from the plane in
which the connecting bars 38 and 40 are disposed. The spacer bar 42
extends between the ends of the torsion bars 33 and 34 and the
spacer bar 44 extends between the ends of the torsion bars 35 and
36. A generally L-shape attaching foot 46 forms the lower end of
the end section 30 and terminates in an attaching bar 48 which is
inclined relative to the torsion bars 32--36, for a purpose to
appear presently.
In FIGS. 2 and 3, a straight end section 49 of the mainspring body
portion 28 is illustrated, and as there shown, the section 49 is
located between the vertical planes described above. In other
words, the end section 49 is disposed in a vertical plane located
between the plane in which the bars 38 and 40 are located and the
plane in which the bars 42 and 44 are located. Since the torsion
bars 33 and 35 extend between these latter planes, they are
engageable with the section 49 to limit downward movement
thereof.
In the assembly of the mainsprings 14 and 16 with the frame 12, the
springs 14 are positioned so that the end portions 30 thereof are
supported on the end rails 18. The usual staples 50 are employed to
connect the attaching bars 48 to the end rails 18 as shown in FIG.
1. Likewise, the mainsprings 16 are extended transversely of the
mainsprings 14 and positioned so that their end portions 30 are
supported on the frame members 22. As shown in FIG. 1, the body
portion 28 in each mainspring 16 is positioned in substantial
vertical alignment with one edge of a frame member 22. This locates
the attaching foot 46 intermediate the edges of the support member
22 so that there is no danger of the attaching bar 48 extending
beyond either edge of the support member 22. The reduced length of
the bars 48 relative to the torsion bars 33--36 facilitates this
location.
The end torsion bars 32 in the mainsprings 14 and 16 are secured by
clips 52 (FIG. 1) to the border wire 24 which is of continuous
rectangular shape corresponding to the shape of the frame 12, and
the body portions 28 for the mainsprings 14 and 16 are secured by
clips 54 to the internal support springs 26.
In the operation of the spring and frame assembly 10, first assume
that the assembly is not under load. In such case, all of the
spring end portions 30 are in their upwardly expanded positions
illustrated in FIGS. 4 and 5 in broken lines in which the spring
end portions 30 maintain the spring body portions 28 at a
predetermined elevation relative to the frame 12. In the expanded
position of the spring end portion 30, the connecting bars 38 and
40 are inclined relative to each other and the spacer bars 42 and
44 are substantially upright. Thus, the height of the spring body
portions 28 relative to the frame 12 can readily be adjusted to a
desired height by forming the spring end portions 30 with spacer
bars 42 and 44 of the necessary length.
When the assembly 10 is loaded, the spring body portions 28 are
moved toward the frame 12, as shown in full lines in FIG. 4. During
such movement the border wire 24 must move straight down and it is
important to note that the torsion bars 32, 33 and 35 are all
subjected to substantially the same angle of twist. In other words,
these torsion bars 32, 33 and 35 cooperate so that they provide
substantially equal resistance to the load tending to compress the
spring end portion 30. As a result, overstressing of a spring
component is avoided to thereby avoid the danger of the spring
taking a set in response to repeated loads.
The spring end portion 30 is constructed so as to limit deflection
of the spring body portion 28, in the manner illustrated in FIG. 5.
The spacer bar 42 will engage the frame member 22 when the spring
end portion 30 has been fully compressed. In the position of the
spacer bar 42 engaged with the frame member 22, the torsion bars 33
and 35 are located directly below the end section 49 of the spring
body portion 28 so as to be engageable therewith and limit downward
movement of the body portion 28. This location of the torsion bars
33 and 35 is achieved by constructing the spring end portion 30 so
that the torsion bar 32 is of reduced length relative to the
torsion bars 33--36, as shown in FIG. 3. As a result, the spring
body portion 28 cannot snap over the end portion 30 and continuous
downward movement toward the frame 12 is thus prevented. Thus, the
configuration of the spring end portions 30 effectively limits
deflection of the mainsprings 14 and 16.
Also, as shown in FIG. 5, the torsion bars 32, 33 and 35 have all
been twisted through substantially the same angle, so that they
continue to cooperate in sharing equally the load applied to the
spring assembly. This is accomplished by inclining the connecting
bar 38 relative to the horizontal at an angle on the order of
45.degree. and by locating the connecting bar 40 so that it moves
through an angle of substantially 45.degree. between its expanded
and compressed positions shown in broken and solid line positions,
respectively, in FIG. 5. The result is a substantially equal
twisting of the torsion bars 32, 33 and 35. It should be understood
that when it is stated that the connecting bars 38 and 40 are moved
through angles of approximately 45.degree., it is meant that the
angle could vary substantially from this figure since a difference
in angle of twist of several degrees will not be critical in the
load sharing function of the torsion bars involved.
During compression of the spring end portion 30, the attaching foot
46 is urged downwardly tightly against the frame member 22. The
inclining of the attachment bar 48 provides the leg 46 with
improved resistance to pivoting of the spring end portion 30, thus
providing an improved attachment base for the spring. In addition,
this inclining of the attachment bar 48 enables the bar to be
formed of a reduced length relative to the torsion bars 33--36.
Thus, in the spring end portion 30 the reduced lengths of the
torsion bar 32 and the attachment bar 48 also imparts advantageous
economies in the manufacture of the spring and frame assembly
10.
From the above description it is seen that this invention provides
an improved spring and frame assembly 10 in which the torsion bars
32, 33 and 35 cooperate, by virtue of the configuration of the
spring end portion 30 to resist spring loads in a manner to
preclude the end portion 30 from taking a set in response to
repeated loads. Furthermore, by virtue of the reduced length of the
torsion bar 32, and the cooperation therewith of the spacer bars 42
and 44, the spring end portion 30 has an inherent limited
deflection characteristic which is desirable for spring life
purpose. The inclined attachment bar 48 imparts added firmness to
the mounting for the spring assembly 10, and all of these
characteristics cooperate to provide an assembly 10 which can be
economically manufactured and used comfortably over a prolonged
service life.
It will be understood that the spring and frame assembly
particularly for box springs which is herein disclosed and
described is presented for purposes of explanation and illustration
and is not intended to indicate limits of the invention, the scope
of which is defined by the following claims.
* * * * *