Metal cabinet for assembly by the user from knocked-down condition

A rectangular metal cabinet of the panel type intended for sale and transport in a knocked-down condition for assembly with self-tapping screws penetrating the mated edges of the panels. The rear panel has flanges along its lateral edges and the side panels have flanges along their front edges, the flanges being of the box type to impart torsional rigidity at the four upright corners of the cabinet and to receive as well as shield and conceal the tips of the self-tapping screws. The cabinet has one or more rectangular shelves dimensioned to extend to the walls thereof, with the upright flanges being notched out at shelf level by an amount equal to the thickness dimension of the shelf to enable engagement between the edges of the shelf and the walls of the cabinet as well as support for the shelf in the vertical direction. The rear panel consists of left and right-hand sections which are symmetrical and of identical width having box type flanges at their central edges joined in abutting relation. Each of the doors has a flange of box type extending about the periphery to define a central panel. A reinforcing channel having integral wing portions is rigidly adhered to the panel. The wing portions are angled at a shallow angle to define holding spaces of sharply acute cross section containing a charge of adhesive. The structure is preferably fabricated by punching and bending of prefinished stock with avoidance of localized heating by spot welding or the like.

The art of making metal cabinets is highly developed and it is well known 
to form cabinets of flanged metal panels joined together at mating edges 
by self-tapping screws or the like. The flanges in such prior cabinets 
take various forms, all of the way from straight, or unbent, flanges to 
flanges of "L" (singly bent), "C" (doubly bent), and "box" shape. For the 
most part metal cabinets have been pre-assembled, finished, usually by 
spray coating, and packed in a full-sized protective carton or the like 
for storage and shipment. Most of the construction techniques are suited 
for use only with cabinets which are pre-assembled at the factory and in 
which spot welding is the most common mode of fastening the parts 
together. As a generality, cabinets are not constructed and fitted in a 
way which permits on-site assembly. On the other hand efforts to produce a 
cabinet which can be assembled by the user have been characterized by poor 
structural techniques frequently resulting in a shoddy looking, "tinny" 
product of limited strength and rigidity and with the inside of the 
cabinet showing raw metal edges and exposed, projecting screw points which 
are both unsightly and hazardous. 
Prior constructions have often utilized door reinforcing channels as shown, 
for example, in prior U.S. Pat. No. 3,023,068 with such channels being 
generally spot welded in place. The weld spots at spaced intervals result 
in concentrations of stress as the door is warpingly deformed which may 
occur, for example, when one corner of the door "sticks" as the door is 
opened. The weld spots, moreover, form depressions or dimples in the outer 
surface of the door which deface the door and add to the "cheap" 
appearance. Moreover, use of welding techniques in cabinet constructions 
precludes the use of pre-finished or pre-coated stock. The necessity for a 
final finishing step greatly limits the finishes which may be employed, 
ruling out, for example, the use of decorative "printed" designs. 
It is, accordingly, an object of the invention to produce a metal cabinet 
which is intended for sale and transportation in a knocked-down condition 
for assembly by the user at the point of use. It is, therefore, a general 
object of the invention to provide a cabinet construction which possesses 
all of the advantages of sale and transport in a knocked-down state 
including densified economical shipment, conservation of storage and floor 
space at the dealer, convenient "take home" handling on the part of the 
buyer and a high degree of economy at each step in the process of 
manufacturing and distribution resulting in a substantial saving which, in 
a competitive market, serves to benefit the consumer. Erection at point of 
use enables use of the cabinet, particularly where of large size, in 
places where it would be difficult or impossible to take a pre-assembled 
cabinet as, for example, in an attic or other space having a narrow or 
difficult access opening. 
It is another, and related, object to provide a cabinet construction which 
may be pre-finished or pre-coated in a wide variety of finishes and 
designs on the flat sheet metal stock with the stock being fed to the 
punching and bending machines conveniently from a pre-coated and re-rolled 
web. This enables use of a wide variety of printed designs which are 
preserved intact to the customer, free of any marring due to the cutting 
and bending operations and without the damage to the finish which always 
accompanies use of spot welding. Pre-printing by an adherent and bendable 
finish may be performed on a cost per square foot which is only a fraction 
of the cost of spray painting, for example. 
It is another object to provide a cabinet construction which is inherently 
easy to erect, in which the parts slip into place logically and without 
necessity for detailed assembly instructions, requiring only the 
application of a limited number of self-tapping screws to provide a 
monolithic assembly which remains permanently tight. 
It is yet another object to provide a cabinet construction which is 
exceptionally strong and rigid, which employs box-type flanges throughout 
at all critical points, particularly at all four upright corners of the 
cabinet, and in the doors, to impart a high degree of torsional rigidity. 
It is a related object to provide a cabinet which can be made of 
relatively light gauge metal and in which the metal is stressed 
efficiently to develop high strength and durability, completely avoiding 
any "tinny"effect. Thus it is an object to produce a cabinet intended for 
heavy duty loading and capable of withstanding rough usage, a cabinet in 
which the shelves, for example, may be severely overloaded without damage. 
In this connection it is an object to provide a cabinet having a door 
construction employing box-type flanges about its periphery plus a 
reinforcing channel of special construction cemented with adhesive to 
produce a weld-free door characterized by a high degree of torsional 
stability, a door in which the torsional stresses which are set up under 
some conditions are resisted with stress distributed on an "area" basis 
minimizing warp-type deformation. Indeed, the solidity of the door 
construction as compared to the filmsy doors provided on a conventional 
cabinet adds greatly to the appeal and saleability of the entire unit. 
It is yet another object to provide a metal cabinet construction which is 
almost entirely free of evidence of hardware both inside and out. 
Externally visible screw heads are at a minimum and the construction is 
such that the box-type flanges which are employed not only receive, but 
shield and conceal, the tips of the self-tapping screws which are used in 
the construction. The lack of visible hardware and projecting points not 
only creates a rich and finished internal appearance but results in a safe 
construction in which clothing or other items which are stored in the 
cabinet cannot be inadvertently caught and torn on a projecting screw tip, 
nor fingers cut or scratched. 
It is still another object to provide a metal cabinet intended for sale and 
transport in a knock-down condition which is easily and economically 
manufactured because of the use of simple repetitive shapes and bends, use 
of duplicate parts, compact packaging, and almost entire saving of 
assembly expense. Tooling expense is minimized since the tooling is 
relatively simple and since the same tooling can be economically employed 
in the construction of differently shaped panels. The cabinet may be 
constructed in a wide range of sizes and outfitted, without major change 
of design, for a wide variety of usage, either with shelves or without.

While the invention has been described in connection with certain preferred 
embodiments of the invention, it will be understood that we do not intend 
to be limited to the particular embodiments shown but intend, on the 
contrary, to cover the various alternative and equivalent constructions 
included within the spirit and scope of the appended claims. 
Turning now to the drawings there is shown in FIG. 1 a cabinet 10 
constructed in accordance with the invention, used as a wardrobe, the same 
cabinet in its disassembled state being illustrated, in exploded 
condition, in FIG. 2. However, it will be understood that the various 
parts of the cabinet, sold in knocked-down condition, are, upon leaving 
the factory, densely packaged, with the panels nested flatly together in a 
wrapping or container of small dimension. The cabinet includes a top panel 
11, a bottom panel 12, side panels 13, 14, a rear panel 15 and a pair of 
doors 16, 17 mounted on hinges 18. 
Below the doors there is mounted a "kick" panel 20, forming a shallow 
internal well for rubbers or the like. Inside of the cabinet, toward the 
top, is a shelf 21. The shelf 21 is supported, at its center, upon a 
column 22 which extends downwardly to engage the top edge of the "kick" 
panel. For receiving of garments on conventional hangers a horizontal bar 
23 is secured, at its ends, to small brackets 24 mounted on the side 
walls. All of these parts are made of thin gauge metal, preferably steel, 
having a gauge which depends upon the size of the cabinet and the use to 
which it is to be put but which may, for example, be 26 gauge. 
In accordance with the present invention the rear panel has box type 
flanges 31, 32 along its lateral edges and the side panels have box-type 
flanges 33, 34 along their front edges to impart torsional rigidity at all 
four upright corners of the cabinet. By a "box-type" flange is meant an 
edge which is bent along three parallel crease lines to form a contained 
space of rectangular cross section which is closed on three sides and at 
least partially closed on the fourth side. Taking the flange 31 on the 
back panel 15 by way of example, it will be noted in FIG. 3 that the 
parallel crease lines, indicated at 35, 36 and 37 define a first closed 
side 15, a second closed side 35a, a third closed side 35b and a fourth, 
partially closed, side 35c. 
The box-type flanges 31, 32, it will be noted, stop short of the upper and 
lower edges of the panel to define upper and lower "straight" flanges 41, 
42 which overlap the rear edges of the top and bottom panels 11, 12, 
respectively. The top and bottom panels are preferably formed with a 
box-type flange at the regions of overlap to receive and conceal the tips 
of the self-tapping screws which penetrate suitable openings 43 formed in 
the straight flanges, which openings are aligned with openings (not shown) 
along the rear edges of the top and bottom panels, respectively. 
In carrying out the invention the rear lateral edges of the side panels 13, 
14 are each formed with an "L" type flange 45 which extends around and in 
back of the rear panel 15 in an overlapping position aligned with the 
box-type flanges 31, 32 on the latter, with self-tapping screws 
penetrating each "L" type flange and with the tips of the screws, as 
indicated at 46, (FIGS. 3a and 4) projecting into the associated box-type 
flange. It will be apparent that since the screw tip 46, and the other 
screw tips in the series, being enclosed in a box-type flange, are 
shielded from view and even more importantly are shielded from catching on 
any garments or other objects which may be stored in the cabinet. 
The upper and lower edges of the side panels 13, 14 terminate in "L" type 
flanges 51, 52, with the flange 51 serving as a flat seat for supporting 
the top panel 11 which is held in place by means of a set of upwardly 
directed screws 53 (FIG. 3a) and a set of forwardly directed screws 54 
penetrating openings 43 along the upper edge of the back panel. The tips 
of the screws 53, 54 are both shielded by the box-type flange formed at 
the adjacent end of the top panel. 
The shielding of the screw tips has been carried throughout the 
construction as shown in the fragmentary section FIG. 5. This figure shows 
the joint between the kick panel 20 and the bottom panel 12 which carry 
box-type flanges 55, 56, respectively, which are in abutting relation and 
held together by a series of screws 57. It will be noted in the joint of 
FIG. 5 that both the head and the tip of the screw are fully shielded. A 
similar box-type flange 58 mates with the straight type flange formed at 
the lower edge 42 of the back panel (FIG. 2). 
In accordance with one of the aspects of the present invention the rear 
panel 15 is in the form of two vertical sub-panels, that is, it consists 
of left and right-hand sections, having box-type flanges at their central 
edges joined in abutting relation by self-tapping screws in which the head 
of each screw is concealed in one flange and the tip in the other, the 
sections preferably being symmetrical and of identical width. Thus 
referring to FIGS. 2 and 4, the rear panel indicated generally at 15 
consists of two sections, a left-hand section 15a and complementary 
right-hand section 15b with box-type flanges 61, 62 thereon joined in 
abutting relation by a series of screws 63. The sections 15a and 15b of 
the rear panel are shown in FIG. 2, for convenience, at reduced width; the 
width in fact corresponds to that of the doors. 
Making the rear panel 15 in this fashion is accompanied by a number of 
advantages: In this first place the central box flanges impart substantial 
torsional rigidity which comes about by the breaking up of a large expanse 
of metal of single thickness and by the fact that box-type flanges are 
used rather than flanges of simpler type. A second main advantage is that 
the sections 15a, 15b of the back panel, are of half size, being equal in 
width to the doors 16, 17 which are the next largest of the components, 
thereby permitting more compact building into a package for transport and 
storage. 
In accordance with one of the features of the invention the rectangular 
shelf, indicated at 21, is dimensioned to extend to the walls of the 
cabinet with downwardly-turned edges to define a thickness dimension, the 
box-type flanges 31, 32 and 33, 34 being notched out at shelf level by an 
amount equal to the thickness dimension of the shelf to accommodate 
engagement between the edges of the shelf and the walls as well as to 
provide support for the shelf in vertical loading. Thus the shelf 21 has 
front and rear downwardly turned flanges 71, 72 and end flanges 73, 74, at 
least the flanges 71, 72 being of the box type. For the purpose of 
accepting the corners of the shelf the flanges 31-34 are respectively 
notched out as indicated at 81-84. Where the rear panel 15 is formed in 
two sections, with flanges 61, 62 thereon abutted together, such flanges 
are also notched out at shelf level to the thickness dimension of the 
shelf as indicated at 85, 86 (FIG. 2). 
In accordance with one of the features of the invention the doors 16, 17 
are formed with peripheral box type flanges as indicated at 93, 94 (FIG. 
2), the door hinges 18 each having a pair of flaps, with self-tapping 
screws for penetrating the same for securing the hinges to the box-type 
flanges on the doors and side panels, with the tips of the screws being 
received in a shielded and concealed position (see FIG. 1). 
For augmenting the torsional rigidity of the doors, each of the doors is 
provided with a reinforcing metal channel having integral wing portions 
extending continuously along the sides thereof and symmetrically angled in 
the direction of the central panel of the door so as to make a shallow 
obtuse angle with one another and so that, when the remote edges of the 
wing portions are in contact with the door panel, cement-holding spaces of 
sharply acute cross section are formed, with a charge of adhesive cement 
being applied in the holding spaces for rigidly bonding the channel to the 
door panel. 
Thus, taking the door 17 as representative, a reinforcing channel is 
applied having the shape shown in profile in FIGS. 6 and 6a. The 
reinforcing channel 100 has a flat central portion 101, sides 102, 103, 
and integral wing portions 104, 105. The wing portions extend continuously 
along the sides of the channel and are symmetrically angled in the 
direction of the central door panel so as to make a shallow obtuse angle 
with one another as indicated at .alpha. (FIG. 6a). As a result when the 
remote edges 106, 107 of the wing portions are in contact with the door 
panel, a cement holding space 108 (FIG. 6) is formed having a sharply 
acute cross section as indicated by the angle .beta.. Into this holding 
space is placed a charge of adhesive 109 (FIG. 6a). Such adhesive may 
preferably consist of a quick setting two-part urethane composition known 
in the art. 
This is the only part of the construction which requires pre-assembly: A 
strip of adhesive 109 is applied by a gun or the like interposed between 
the panel 17 and the wing portions 104, 105 of the reinforcing channel, 
and the channel is then pressed into position as shown in FIG. 6. This 
causes the cement to spread, but because of the concentrated contact which 
exists at the outer edges 106, 107 of the wing portion, the adhesive does 
not escape outwardly but any excess crowds inwardly into the body of the 
channel where it is out of sight. Thus the adhesive need not be applied 
with great care and there is no need to wipe any of the excess away. The 
wing portions 104, 105 are preferably formed with one or more ribbed 
embossments 110 to provide longitudinal grooves into which the cement 
extends to produce a strong bond between the cement and the inner surface 
of the channel. Preferably the thickness dimension of the reinforcing 
channel exceeds the door thickness in the original or unstressed state, 
and the wing portions 104, 105 have sufficient resiliency so that when the 
reinforcing channel has been pressed into its seated and cemented position 
the channel is substantially flush with the box-type flanges on the door. 
Thus referring to FIG. 6 where the door thickness is indicated at t, the 
reinforcing channel has an initial thickness of T which exceeds t by a 
small amount. Thus, after the adhesive has been applied and the channel 
located in position, the door is clamped between two opposed clamping 
surfaces 115 (FIG. 6) which squeeze the reinforcing channel toward the 
door panel, slightly flattening the channel until it occupies a parallel 
position substantially flush with the box-type flanges at the periphery of 
the door. This is accompanied by an internal spreading-out of the adhesive 
so that it adheres to almost the entire presented surface area. At the 
same time, using metal for the channel which is resilient and flexible, 
the clamping overcomes, and permanently removes, any "waviness" either at 
the edges of the channel or in the door panels themselves. As soon as the 
adhesive has set, the clamping surfaces may be removed. 
By making the channel the same effective thickness as the box flange 94, 
the door may seat flatly with respect to the front edge 71 of the shelf 
21, and against the front edge of any additional shelves, if used, so that 
the shelves reinforce the door against forces which may be applied to the 
central portion of the door panels. Moreover, making the channels of such 
"maximum" thickness, in other words by making the channels as "boxy" as 
possible within the door thickness limitations, results in maximum 
resistance to torsional, or warping, type deflection, without 
substantially subtracting from the cubic capacity of the cabinet. However, 
it will be recognized that if desired the channels may be tailored to a 
final thickness which is uniformly less than the thickness t of the box 
flange by inserting a shim of uniform thickness between the inner clamping 
surface (lower clamping surface as viewed in FIG. 6) and the channel when 
the parts are clamped together. 
It is found that use of an adhesive 109 such as polyurethane, with 
extensive and continuous area engagement with both of the adhered surfaces 
has numerous advantages over the usual spot welding techniques. In the 
first place it permits use of pre-finished stock, the surface finish of 
which would be locally destroyed by the welding heat while, at the same 
time, avoiding the unsightly "dimples" which always accompany use of spot 
welding, as already mentioned. Moreover, welds, particularly where made in 
the usual limited number, form concentrated stress points as the door is 
torsionally twisted, or warped, incident to hard usage, whereas by using 
adhesive in a continuous and extensive layer, warping forces are 
distributed and resisted uniformly over a large area of adhered surface 
resulting in high strength, reliability and a long useful life. 
There is still another advantage in the use of a channel formed and adhered 
as described above, and that is that the charge of adhesive in the sharply 
arcuate space serves as a muffling or dampening agent, avoiding the 
"tinniness" of the usual metal door constructed in large size of thin 
metal and providing a more "solid" sound and feel. 
While the cabinet constructed in accordance with the present invention is 
particularly applicable to use as a wardrobe, as shown in FIGS. 1 and 2, 
it is equally usable with only minor modification as a cabinet containing 
a full complement of shelves as illustrated in FIGS. 7 and 8. In these 
figures corresponding elements have, for the sake of simplicity, been 
given the same reference numerals as in the earlier wardrobe embodiment, 
and the added elements have been given corresponding reference numerals 
plus a prime. Thus there are, in addition to the shelf 21, three 
additional shelves 21' which are preferably identical thereto. Whereas the 
original shelf 21 was described as fitted at the corners into notches 
81-84 formed in the cornerposts 31-34, respectively, the added shelves 21' 
are fitted at their corners in notches 81'-84'. Similarly, where the 
original shelf 21 was accommodatingly received in notches 85, 86 in the 
box flanges 61, 62 at the center of the rear panel, matching notches 85', 
86' are provided at shelf level for the reception and support of the 
additional shelves 21'. While the additional notches 81'-86' have an 
inevitable effect upon the monolithic integrity of the box flanges in 
which they are formed, any loss of strength in the box flanges due to the 
notching is more than made up for by the bracing effect of the installed 
shelves. Preferably the notches 81'-86' are tailored to the thickness 
dimension of the edge flanges of the shelves so that the cornerposts 
formed by the flanges 31-34, as well as the back posts formed by the box 
flanges 61, 62 in the rear panel provide direct support for any heavy load 
which may be placed upon one of the shelves; thus total reliance for 
support of shelf loading need not be placed upon the self-tapping screws 
which engage the shelf flanges. Accordingly, the term "support" as used 
herein is not limited to the type of support which would be provided at a 
tightly fitted, notched joint. On the contrary the notches 81'-86' are 
preferably made a slight amount oversize to facilitate assembly so that 
bearing contact may not be uniformly achieved by each shelf at each 
supporting post. Thus the term "support" as applied to the notched posts 
refers not only to the actual support upon initial assembly but to the 
potential support which may occur upon failure or loosening of the 
self-tapping screws at the post positions. Each shelf is positively and 
reliably supported even though the assembler, due to lack of following of 
the assembly instructions, may fail to insert or tighten some of the 
screws in the construction. 
It will be apparent that the features and advantages of the invention, 
stated earlier, have been abundantly realized. Erection is easy and 
obvious, with most of the parts dropping quite logically into their 
pre-assigned positions, even for one who may be totally uninformed on 
cabinet construction to produce a structure which is inherently strong and 
rigid and which is distinguished, both inside and out, by a clean 
"finished" appearance, with no screw tips and only a limited number of 
screw heads being visible to a casual observer. The structure, as 
described, is distinguished by a total lack of welding and all of the 
parts are simply formed from stock which may be, and preferably is, 
pre-finished, resulting in a high degree of attractiveness and economy. 
Although it is preferred to use the usual pointed and hardened self-tapping 
screws applied by a screwdriver in the usual way, and while conventional 
self-tapping screws have the advantage that access to the inner end is not 
required, it will be apparent to one skilled in the art that an equivalent 
two-piece fastener may be used without departing from the invention. For 
example, the holes formed in the metal may be simply clearance holes and 
holding effect may be achieved by threading the screws into a receiving 
nut or clip at the inner end, which nut, or clip, may be formed from a 
plastic such as nylon or from metal, either with or without the 
self-tapping effect. 
While the shelves have been referred to as being dimensioned to provide 
"engagement" with the side walls, such term refers to a cooperative 
relationship which may stop short of actual touching. 
In the preferred embodiment of the present invention flanges of the box 
type are employed not only for maximum torsional rigidity but for 
receiving, shielding and concealing the tips of the self-tapping screws 
used in the assembly. It will be appreciated by one skilled in the art 
that the invention, in certan of its aspects, is not limited thereto and 
that such worthy objectives can be largely satisfied by use of flanges 
which are doubly bent into squared "C" configuration rather than triply 
bent. Such a modification might be desired, for example, where it is 
desired to produce a cabinet which partakes of the advantages described 
above but which is intended for maximum economy of manufacture.