Bedstead storage box

The bedstead storage box may be adapted as a bedstead for any regular-size bed, including king-size. It includes a shallow box to support the bed off the floor, a lid to carry a bed assembly including the springs, mattress and bedding, hinges to position the lid on the box and to serve as fulcrum when the lid is raised, gas springs disposed between the lid and box to counterbalance the weight of the load when opening the box, and a lock to secure the box in the closed position. If the bedstead storage box is to be situated with the hinged side adjacent to a wall, the use of an elevated hinge permits the bed to stand closely adjacent to that wall without interference when raising the lid.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention is in the field of bedsteads with bottoms having receptacles, 
drawers, and compartments, Class 5, Subclass 308, and the related field of 
sofa beds, Class 5, Subclass 58. 
2. Prior Art 
To use the space beneath a bed or a sofa for storage has been an objective 
shown in the patent literature for more than a hundred years, and in all 
likelihood, an objective that has been sought for ever since man first 
raised his bed up from the ground. The space underneath regular-size beds, 
as distinguished from sofa beds, has been adapted for drawers of various 
kinds which slide out to the side of the bed, for example U.S. Pat. No. 
164,290 to Julia B. French, June 8, 1875. H. A. Scheinerman, U.S. Pat. No. 
2,956,290, Oct. 18, 1960, substituted the box spring of a bed with a box 
and gained access to the box from the head and foot ends by elevating one 
third sections of the mattress on a platform that was divided in thirds by 
two transverse sets of hinges, with support for the elevated sections 
provided by a prop. Sofas which have the cushioned part mounted on the 
hinged lid of a storage box are represented many times in the patent 
literature. U.S. Pat. No. 984,685 to J. Luppino, Feb. 21, 1911, for 
example, shows such a box couch with a coil spring counterweighted hinged 
lid. 
The success of the instant invention is due to the remarkable application 
of a relatively new hardware item, the so-called "gas spring." The 
application of gas springs most familiar to our contemporaries is the 
device found on our "hatchback" automobiles to assist in raising the hatch 
door. In the literature of the manufacturers of gas springs may be seen a 
variety of suggested applications for gas springs, including their use as 
adjuncts in hospital beds to permit comfort adjustments. Nowhere, to my 
knowledge or study, has the gas spring ever before been applied as I have 
used it, to permit the easy raising and lowering of a regular-size bed 
assembly complete with mattress, springs, and bedding, for access to the 
voluminous space beneath the bed. 
The Problem 
The problem is to provide storage space within the confines of an existing 
living space--to discover space that has been overlooked or misused, and 
to put that space to productive use. The problem is found in acute form in 
the efficiency apartments of our crowded cities. The problem is seen in a 
unique form in rental vacation condominium apartments, where there is an 
owner who uses the apartment for short periods during the year but who 
otherwise rents to vacationers. The owner needs secure space for storage 
of certain personal goods such as sports equipment and casual clothing 
that he needs only when occupying the apartment. It is commonplace for the 
"owner's locker" to be violated by renters, and a secure, inconspicuous 
owner's locker is a long-felt need. 
The invention in its completed form was reached through a succession of 
steps, each of which ushered in new problems. The solution to the major 
problem was to gain access to the space beneath the bed by putting the bed 
assembly on a platform hinged to a shallow box at one of the four sides. 
The next problem was how to overcome the weight of the bed in raising the 
bed up through an angle that would permit access to the box. That problem 
was solved with the use of gas springs, but another problem was 
encountered: If the bedstead storage box is situated with the hinged side 
adjacent to a wall it must be spaced away from that wall in order to avoid 
conflict between the bed assembly and the wall when the bed is tilted 
open, which is a waste of space. 
SUMMARY OF THE INVENTION 
The bedstead storage box is a shallow rectangular box of dimensions 
comparable to the mattress for the bed, the box having four upright sides 
and a bottom, and a lid for the box to carry a bed assembly including 
springs, mattress and bedding, the lid comprising a platform supported on 
a frame that is hinged to one of the sides of the box so that it may be 
tilted upward at an angle by raising the lid at the side opposite the 
hinged side, to gain access to the space within the box, and gas spring 
counterforce means operating between the box and the lid to counterbalance 
the weight of the lid and bed assembly. If the hinged side of the bedstead 
is to stand adjacent to a wall, an elevated hinge axis may be provided to 
minimize interference of the bed assembly with the wall when the lid is 
tilted open. 
It is an object of the invention to provide access to the space beneath a 
bed for storage of personal goods, wherein the lid and bed assembly may be 
easily tilted upward through an angle sufficient to afford access to the 
space within the box, and to provide this function in a manner that does 
not immediately reveal that the storage space exists, and further to 
provide that the box may be locked in the closed position. 
My invention solves the problem of the owner's locker, providing for the 
first time, full access to the space underneath a regular-size bed, 
particularly a king-size bed, for storage. Since its introduction in the 
Florida condominium market less than a year ago, my bedstead storage box 
has received substantial acceptance and is on its way to being a 
commercial success.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Introduction 
The preferred embodiment of my bedstead storage box (FIGS. 1, 2) includes a 
shallow rectangular box 1 with four upright sides and a bottom 19 that 
rests on the floor of a bedroom. A lid 2 for the box is hinged at one side 
of the box by elevated hinges 3 and counterweighted with gas springs 4. 
The lid is a frame 5 with a platform 6 (FIG. z) to support a bed assembly 
including a mattress 7, box springs s, and bedding (not illustrated). 
This description will feature the bedstead storage box of size to 
accommodate the contemporary "king-size" mattress and accompanying box 
spring pair. The bedstead storage box is adaptable for use with other 
regular-size beds--the single, the full and the queen, and size variations 
thereon. The most dramatic amount of storage is provided by the king-size 
storage box, which affords 22.5 cubic feet of storage space, which 
challenges the storage volume of the popular 36".times.18".times.72" steel 
cabinet, which affords 27 cubic feet. 
The ease of opening and closing the bedstead storage box is remarkable and 
must be experienced to be fully appreciated. 
This account will describe the construction of the box 1, the lid 2, the 
elevated hinge 3, the gas springs 4 for easing the opening and closing of 
the lid and the mechanics of their operation, the lock 9 provided for 
securing the contents of the box from unauthorized access, and the design 
of the parts of the box for shipment within the standard containers of the 
United Parcel Service company. 
The Box, Lid, and Elevated Hinge (FIGS. 1, 2, 3) 
The base of the bedstead storage box is a rectangular wooden box 1 of width 
and length scaled somewhat smaller than the lid 2, to provide that the 
sides of the box are recessed under the sides of the bed assembly by an 
amount (see FIG. 1) to afford toe room for a person standing next to the 
bed, and to give the completed bed an appearance compatible with 
contemporary design. The term &lt;somewhat smaller&gt; as used above is not some 
exact length, but is defined in terms of toe room, and is no greater than 
the length of the instep of one's foot. 
The two parallel sides 10 and the side 11 opposite the hinged side of the 
box are of wood plank construction and are joined at the corners with 
miters reinforced with lengths of angle iron 12 fastened with wood screws. 
The hinged side 13 of the box is a wooden board of width equal to the 
total depth of the storage space and it is set in from the extreme end of 
the box and it is attached to the adjacent sides 10 by means of lengths of 
angle iron 14 secured with wood screws. 
The bottom 19 of the box is made from several flat sections of plywood or 
chipboard of size acceptable for shipment by United Parcel Service, the 
assembled bottom having dimensions slightly smaller than the dimensions of 
the box, so that its edges are inconspicuous when the box is standing in a 
carpeted room. The bottom sections are attached to the bottom faces of the 
four sides with wood screws. 
The platform 6 is also made from several flat sections of plywood or 
chipboard of size acceptable for shipment by United Parcel Service, and 
its overall rectangular dimensions are just slightly smaller than the 
rectangular dimensions of the mattress to be accommodated by the bedstead, 
providing thereby that a person accidentally bumping into the side of the 
completed bed will first encounter the soft bed assembly rather than the 
hard edge of the platform. The platform is 6 is supported by and secured 
to a U-shaped, three-sided frame 5 of wooden beams 23 with mitered corners 
reinforced with pieces of angle iron 24 fastened with wood screws. To 
participate in the elevated hinge at the free end of each side beam, an 
upright strut 25 is fixed and reinforced with a steel el plate 26 which is 
fastened to the inside face of each strut and to the inside face of each 
side beam. The el plates are secured with wood screws. 
An endboard 30 completes the lid frame, being secured to the faces of the 
struts 25 with wood screws (FIG. 2). The endboard serves to keep the bed 
assembly from sliding off the lid when the lid is tilted to gain access to 
the box. The wooden frame 5 is designed to provide that the inside faces 
of the beams 23 are flush with the inside faces of the planks 10, 11 
comprising the box. The beams are thicker than the planks making up the 
sides of the box, with the result that the outside faces of the beams 
slightly overlie the planks. A foam rubber pad (not illustrated) is bonded 
to the undersurface of the beams to cushion the lid to seat noiselessly 
upon the planks. 
In an early example of my bedstead storage box the lid was hinged directly 
to the top edge of one side of the box, as shown in FIG. 4, with the 
unwanted result that if the hinged side of the box were situated closely 
adjacent to a wall the bed assembly at the hinged side of the bed 
conflicted with the wall next to it when the lid was tilted open, and 
necessitating that the hinged side of the bed be spaced away from the wall 
to provide clearance against the conflict, as indicated by the line 15 
(FIG. 4). I solved that problem by elevating the hinge axis to a height 
closer to the top surface of the mattress of the completed bed as shown in 
FIG. 3. Another demand placed on the design of the hinge is that it be 
hidden, because it is an objective of the invention to provide an 
inconspicuous owner's locker for rental vacation condominiums. 
As shown in FIG. 2, to elevate and hide the hinge, I built up the ends of 
the planks comprising the sides 10 of the box with the shim boards 16, to 
support angle iron uprights 17 fixed to the ends. An aperture 31 in the 
top inside face of the each of the two uprights serves to establish the 
hinge pivot axis. Each angle iron upright 17 is welded to a steel 
reinforcement plate 18 that faces on the corresponding shim board 16 and 
is secured thereto with wood screws. To accommodate the uprights 17, the 
hinged side 13 of the box is recessed from the extreme end of the box, as 
reported above. 
The common pivot axis of each elevated hinge 3 is parallel with the side 
13. Lag bolts 27 are used for hinge pins. The threaded end of each lag 
bolt is screwed into the upright wooden struts 25 through apertures in the 
el plates 26. Corresponding apertures 28 in the angle iron uprights 17 
serve as journal bearings for the necks of the lag bolts and define the 
hinge pivot axis. 
To avoid a shearing action on any object that might inadvertently enter the 
angle between the upright el plate 26 and the upright angle iron 17 during 
opening and closing the lid, those members are spaced apart by a thick 
washer 29 that is intermediate on the neck of the lag bolt. 
The hinge mechanism, being constructed within the recess at the hinged side 
of the bed, and having no parts showing on the outside of the bed, is 
completely hidden from view, and gives no suggestion that the bed serves 
for storage. 
The Gas Springs 
The type of spring that I use in my bedstead storage box, the so-called gas 
spring, has been available only in recent years and may be purchased from 
specialty hardware outlets such as Eberhardt Manufacturing Co., of 
Cleveland, Ohio, which distributes the goods of the Gas Spring Corp. of 
Colmar, Pennsylvania. Such springs have found many remarkable applications 
but have never before been used for a bedstead storage box as I have done 
in this invention. 
The gas spring 4 (FIG. 5) is an elongate cylindrical sleeve 32, one end 
being closed and adapted for movable attachment to an anchor point, the 
other end having an aperture sealed upon a piston rod 33 that is fixed to 
a movable piston within the cylinder and which is adapted for movable 
attachment to a second anchor point at its outer end. The piston divides 
the volume of the cylindrical sleeve into two chambers that communicate by 
means of a small aperture drilled through the body of the piston. When 
manufactured, the cylinder is charged with an inert gas at high pressure, 
and because the face of the piston in the chamber containing the piston 
rod is smaller than the opposite face by an area equal to the 
cross-sectional area of the piston rod, and since pressure times area 
equals force, the net force tending to extend the piston rod is greater 
and provides the spring force. When the piston rod is retracted into the 
cylinder, the total volume is reduced by the volume occupied by the rod, 
so that the inert gas pressure is greatest (Boyle's law) and the force 
exerted by the gas spring is at its maximum. The force for any stage of 
piston extension is represented by the line f.sub.1 f.sub.2 of the graph, 
FIG. 6. 
If the piston of a given gas spring is fully retracted by the action of 
some external force and if that force is suddenly removed, the rate of 
extension of the piston rod will be moderated by the rate of flow of the 
compressed gas through the communicating aperture in the body of the 
piston. Such moderated spring action is very desirable in the application 
that I have now made of gas springs in my bedstead storage box. 
When the piston rod is extending, the force required to arrest extension is 
just equal to the spring force, but to reverse the piston rod, an 
additional increment of force to overcome hysteresis must be applied, as 
indicated by f.sub.2 f.sub.3 in FIG. 6. In the case of the gas springs 
that I use in my king-size bedstead storage box, the maximum spring force 
f.sub.1 is 250 pounds, the minimum force is 192 pounds, and the hysteresis 
force is ten pounds. A one-way valve in the body of the piston facilitates 
the flow of compressed gas between the chambers during retraction of the 
piston, but the retraction is nonetheless moderated by the expansion force 
of the spring, a characteristic of the gas spring which, together with the 
moderated extension force, works to provide the very desirable controlled 
opening and closing behavior of the bedstead storage box. 
Each gas spring 4 is attached at its cylinder end to an anchor point on the 
inside surface of the frame of the lid by means of a ball joint, the 
socket 35 being at the end of the spring and the ball 34 being the outer 
end of a lug mounted to a metal reinforcing plate 36. The piston rod end 
is attached to an anchor point on the inside surface of the side of the 
box with a similar ball and socket joint and reinforcing plate 37. 
Reading the drawings, FIGS. 1, 2, 3, it is seen that one end of each gas 
spring is attached to a side of the lid at a point approximately midway 
from the hinged end to the opposite end of the lid. The other end of each 
gas spring is orientated toward the hinge side of the box and is mounted 
at a selected point on the inside face of the corresponding side of the 
box, to provide that the piston rod will be substantially fully retracted 
when the lid is closed, and to provide that the lid will be tilted at an 
angle of approximately 25 degrees when the piston rod is fully extended. 
Mechanics of Operation 
Referring to the schematic, FIG. 3, one may understand the physics of 
operation of the bedstead storage box. Every force tending to open or 
close the lid assembly works to rotate that body on the hinge, according 
to the law of the lever. Moment equals the product of the distance from 
the point where the force is applied to the fulcrum, i.e., the moment arm, 
times the component of that force normal to the moment arm. 
Referring to FIG. 3, the point H is the hinge axis, the point G is the 
center of gravity of the bed lid assembly, W is a vector representing the 
weight of the bed lid assembly, and w is the vector component of the 
weight normal to the arm HG, where w=W cosine .theta.. The closing moment 
is HG.times.w. 
The point S is the anchor point of the gas spring at the lid, F is a vector 
representing the force of the gas spring, and f is the vector component of 
that force normal to the arm HS, where f=F sine .phi.. The opening moment 
is HS.times.f. 
The point L represents a place on the end of the bed lid frame where a 
person would exert a force b to boost the lid toward an open position on 
the arm HL. The boosting moment is HL.times.b. 
The status of the bed lid assembly, whether tending to open or to close, 
depends on the arithmetic sum of the moments working to rotate the 
assembly around the hinge axis. As practiced in my invention these 
variables combine to provide a lid assembly that remains closed if 
undisturbed but may be opened with a small boost to an "over center" 
position above which it operates automatically and at moderate speed to 
its fully open position at the limit of extension of the piston rod. The 
boost applied by the person operating the bed, being applied at the end of 
the long arm HL, is augmented by a mechanical advantage, affording 
excellent control. 
For a lid assembly as in FIG. 3, having a pair of gas springs of 250 pounds 
maximum spring force each, the opening moment has been found at angular 
intervals of five degrees, and plotted in the graph, FIG. 7. For the same 
assembly, the closing moment due to the weight of the assembly has been 
calculated in terms of W (the weight of the assembly) for the same angular 
intervals. The bed lid assembly weight W.sub.min to just maintain the lid 
in the closed position and the weight W.sub.max of the lid that will just 
stay in the fully open position are then found to be 237.4 and 272 pounds, 
respectively. The opening moments for lid assemblies for those weights, 
and for the arbitrary intermediate weights, 245-, 255-, and 265- pounds, 
have been found at five degree intervals, and are plotted (FIG. 7) as a 
set of similar curves. 
The intersection of the opening moment curve with the closing moment curve 
for a lid assembly of a given weight then indicates the opening angle at 
which that lid assembly goes "over center," i.e., the angle at which the 
lid not longer tends to close but now tends to open. This information is 
assembled in the accompanying table. 
TABLE 
______________________________________ 
Boost Forces and Over-Center Angles for 
Representative King-size Bed Assemblies 
Weight of 
Bed Lid Boost Force Force to Over-Center 
Assembly 
to Open Lid Close Lid Angle 
(pounds) 
(pounds) (pounds) (degrees) 
______________________________________ 
237.4 nil 24 0 
245 4 20 2 
255 8 16 5 
265 14 11 8.3 
272 17 8 10.7 
______________________________________ 
The boost force needed to raise the lid from its closed position is equal 
to the product of the moment arm HL (FIG. 3) and the difference between 
the weight closing moment and the spring opening moment. The force to 
close the lid is found in the same way after correcting for hysteresis. 
This information is listed in the table. 
It may be noted that if the weight of an exceptional bed lid assembly is 
heavier than the weight that can be controlled in the illustrated example, 
such heavier assemblies can be accommodated by moving the anchor points 
for the gas springs toward the foot end of the bed, which has the effect 
of increasing the moment arm Ms (FIG. 3), but at the expense of a smaller 
opening angle. For the arrangement illustrated in FIG. 3, the maximum 
opening angle is 25 degrees, which provides good access to the space 
within the box. 
Locking Means 
The bedstead storage box may be secured in the closed position with a lock 
such as a vertical deadbolt lock mounted inconspicuously at the foot of 
the bedstead. Note that "vertical deadbolt" is the locksmith's name for 
the common household surface-mounted security lock, and that as used here 
the bolt works horizontally. Some of the parts of the lock 9 will be 
recognized in FIGS. 1, 2.