Electronic equipment enclosure

The disclosure relates to an electronic equipment enclosure assembled from four basic components including (a) frame rail members, (b) corner connector clips, (c) panel support clips, and (d) panel sheets. The frame members each include a pair of right angled walls terminating at flanges which form adjacent pairs of parallel, longitudinally extending internal and external slots. The internal slots receive the clips of the invention, namely, unique, simply constructed connector clips at the mitered joints to fasten the frame members in an assembled mutually perpendicular relation, and panel corner connector clips to engage and support the wall panels and/or shelves of the enclosure. The novel corner connector clip is generally dish shaped and comprises three extending arm members disposed in planes in a mutual perpendicular relation. Each corner connector arm of eight connector clips is adapted to be inserted into the internal slots of the mitered ends of twelve rails to establish mitered, three dimensional corner joints in the assembly of a parallelpiped skeletal frame. Specifically, each connector arm includes a formed recess portion having an angularly disposed threaded hole formed therein to receive a fastening jackscrew whereby the fastening screw may be tightened to engage the frame member to urge the lateral edges of the connector clip arms against the internal slot walls and at the same time to drive the frame member towards the mitered corner.

BACKGROUND AND SUMMARY OF INVENTION 
Electronic equipment enclosures are commonly constructed by assembling 
rigid frame members made of extruded aluminum at mitered corner joints. 
Typically, the frame members are of a hollow cross section. A corner block 
comprising two or more extending arms is usually employed to fasten 
adjacent frame members. The extending connector arms are arranged to be 
received into the hollowed internal portions of the frame members to 
provide interlocking engagement between adjacent frame members, thereby 
preventing lateral separation. 
The prior art has heretofore proposed several mitered frame corner 
constructions employing three-legged connectors. Representative of such 
prior proposals are the Aschinger U.S. Pat. No. 2,371,493, Humble U.S. 
Pat. No. 3,144,365 and Suchowski U.S. Pat. No. 3,767,237. In each of these 
proposals three frame members are joined in a mitered joint with each of 
the frame members being disposed in perpendicular relationship with 
respect to the remaining members. The angularly extending arms of the 
connector are received within formed cavities provided in the adjacent 
ends of the angularly extending frame members. 
Various fastenings including screws and rivets are utilized to securely 
fasten the connectors within the frame members to firmly hold the frame 
members in an assembled, mitered relation. Typically, where the frame 
members are made from extruded aluminum, a force-fitting connector is 
employed whereby the connector holds the frame member by a friction 
engagement. 
As one of its basic objectives, the present invention seeks to provide an 
electronic equipment enclosure assembly incorporating a novel and improved 
mitered frame connection which may be easily and inexpensively constructed 
in any size from a standard set of components, namely, extruded framing 
rails, of unique cross section, sheet metal paneling, and two types of 
novel connector clips. Each of the unique connector clips disclosed herein 
is constructed from a single piece of sheet metal by a simple stamping 
and/or bending operation. 
Generally, the new electronic equipment enclosure is constructed by 
assembling extruded aluminum frame rail members as mitered corners to form 
a parallelpiped skeletal framework. Each frame rail is of a hollow 
construction and comprises two lateral, longitudinally extending frame 
walls in right angled relation. The ends of the frame members are mitered 
at 45.degree. angles so that contiguous frame members may be assembled 
into a mitered joint in known fashion. 
Each of the new and improved frame rails includes a pair of spaced, 
parallel longitudinally extending inner and outer slots at each lateral 
edge thereof. The outer slots receive wall panels for closing off the 
equipment enclosure, while the inner slots receive the corner connector 
clips and the panel support clips. 
Specifically, the inner slots cooperate with a new and improved 
dish-shaped, corner connector clip to securely fasten contiguous frame 
members at the mitered corners. The novel connector clip of the present 
invention comprises three extending arms in mutual perpendicular relation 
joined at a flat bottom of a dished central portion, which bottom is in a 
plane disposed at a 45.degree. angle to each of the arms. The connector 
arms are loosely received in the inner slots of the frame walls for easy 
assembly. The edges of the connector arms engage the walls of the pairs of 
inner slots of each of the frame members and thereby tend to secure the 
frame members from transverse displacement at the mitered joint. 
In accordance with the invention, the mid-region of each corner connector 
clip arm is bent to form a recessed portion. A threaded hole is formed in 
an inclined surface of the recess and a fastening jackscrew is threadedly 
received into the hole. After the connector arm is properly positioned in 
the frame member, the fastening jackscrew may be threaded to engage the 
frame member in an angled relation, whereby tightening of the fastening 
screw will also tend to drive the frame member towards the mitered corner 
and to establish a tight, firm mitered joint with the two adjacent rails. 
As another feature of the present invention, a series of panel mounting 
clips is provided to mount both side walls and shelves to the 
parallelepiped skeletal frame. Typically, electronic equipment enclosures 
of the present type require shelves. Due to the great variety of size and 
shape of the equipment generally enclosed in such enclosures, it is 
advantageous to provide means to mount shelves in any desired position. 
Accordingly, each of the panel mounting clips comprises a frame rail 
engaging arm in right angled relationship to a gusset-like shelf 
supporting tab. The shelf tab is adapted to project at right angles to the 
frame rails into the interior equipment positions of the enclosure. The 
triangular shape allows the tab edges to extend into the plane of the 
edges of the innermost walls of the frame rails. A pair of winged portions 
project from the tab and are disposed to lie within the planes of the 
innermost rail walls. Therefore, the arrangement of the winged portions is 
such that when the panel mounting clip is inserted into the frame rail, 
the winged portions form extensions of the innermost lateral walls 
thereof. Side panels of sheet metal or the like may then be removably or 
permanently mounted to the equipment enclosure by appropriate fastening 
means connecting the panels to the winged portions of the mounting clips. 
The use of winged portions to mount the side panels rather than extended 
walls of the frame rail extrusions greatly reduces the bulk and weight of 
the frame rail members that would otehrwise be required, since the winged 
portions serve as extensions of the frame walls in only those regions 
where the side panel is intended to be secured to the frame. 
The foregoing objects and advantages of the present invention will be 
further appreciated from a consideration of the following detailed 
description and accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings and initially to FIGS. 1-5, the numeral 10 
designates generally an electronic equipment enclosure comprising twelve 
frame rail members 11 and six sheet metal wall panels 12. The frame 
members 11 are extruded aluminum and in cross section (FIG. 2) are formed 
primarily by two lateral, longitudinally extending, mutually perpendicular 
walls 13. The ends 14 of the frame rail members 11 are cut at 45.degree. 
angles in known manner so that they may be connected to form a mitered 
corner joint 15 (FIG. 3). 
The primary walls 13 of the frame rails 11 cooperate with an intermediate 
parallel wall 8, and connecting wall 8' to form an external, 
longitudinally extending slot 17. Similarly, an internal, longitudinally 
extending slot 18 is formed by inner frame walls 9, connecting walls 9', 
and the intermediate wall 8. The side panels 12 of the enclosures 10 are 
received into the outer slots 17, as shown in FIG. 2, for permanent 
mounting, as will be described in detail hereinafter. 
Each mitered corner joint 15 is formed by the joining of the ends 14 of 
three adjacent frame rails 11, with each rail 11 being disposed at a right 
angle to the plane defined by the remaining two rails. In accordance with 
the invention, the frame rail members 11 are held in an assembled relation 
by a unique, dished, one-piece corner connector clip, designated generally 
by the numeral 19. The connector clip 19 is conveniently manufactured from 
a specially pre-cut sheet metal blank 19' by a simple stamping operation, 
utilizing circular dish-shaped dies, which bends the connector into its 
final three-dimensional shape. 
The connector clip 19 comprises three extending arms 20 defining X, Y, and 
Z axes, which are joined by a central flat portion 25 disposed in a plane 
at a 45.degree. angle to the three arms. The arms 20 are inserted into the 
slots 18 of each frame member 11, as shown in FIG. 6. Each connector arm 
20 may be slightly arcuate in cross section, as clearly illustrated in 
FIGS. 2 and 3; the lateral edges 21 of each arm 20 are smoothly received 
in the internal slots 18. The physical engagement between the walls of the 
internal slots 18 and the connector edges 21 secure the frame members 
against transverse displacement at the mitered joint 15. A recessed 
portion 22 is defined by a bend in the mid portion of the extending arm 20 
and has an inclined surface 24. The surface 24 is provided with a 
centrally positioned threaded hole 26. Fastening jackscrews 23 are 
threadedly received in the holes 26 and screwed down into engagement with 
a complementary frame member 11 to firmly secure the connector clip 19 
within the complementary frame member 11. 
Due to the incline of surface 24, the fastening screw 23 will engage the 
frame member 11 at a driving angle. The end of the screw 23 is formed to a 
threadless engaging tip 27. The angle formed by the engaging tip 27 and 
the frame member 11, is such that engagement pressure of the fastening 
screw 23 will drive the frame member 11 towards the mitered joint 15 and 
thereby prevent longitudinal displacement and form a tight joint. Of 
course, the engagement pressure of the fastening screw 23 will also 
produce a tight friction engagement between the extending arms 20 and the 
walls of the internal groove 18. 
The lateral edges of the corner connector arms 20 are provided with 
triangular shaped cutouts 28 which relieve bending stresses during 
formation of the connector and provides the requisite clearances for final 
assembly. Likewise, for ease of formation and to accommodate a tight 
abutment of the rails at the mitered joint 15, the connector clip 19 and 
the blank 19' include three U-shaped cutouts 29. As shown, the cutouts 29 
allow the conjoining end portions of the frame member 11 to meet in an 
edge-to-edge, tight relationship and allow the clip to pass over the 
narrowed opening or throat portion 55 between walls 9 (FIG. 3). 
To provide easy access to equipment enclosed within the enclosure 10, 
several of the side panels 12 are removably secured to the enclosure 10. 
Referring to FIGS. 6-8, a new and improved panel mounting clip 37 is 
shown. The panel mounting clip 37 is provided with a triangular gusset 
shaped shelf-support tab 39 integral with a support arm 38 and in a right 
angled relation thereto. In this manner, when the mounting clip 37 is 
secured to a frame member 11, the gusset tab 39 will extend into the 
enclosure 10 for mounting a shelf 46 by fastener 47, as shown in FIG. 7. 
The frame rail engaging arm 38 of the mounting clip 37 is, of course, 
inserted in the frame member 11 and received into the internal slots 18 to 
secure the mounting clip 37 against transverse displacement. The mounting 
clip 37 is secured against axial displacement by a fastening screw 45 
which is similar to screws 23. 
In accordance with the invention and in order to removably mount a side 
panel 12, the panel connector 37 is provided with winged portions 40 
extending at right angles to the gusset tab 39. The winged portions 40 
will form continuations of the inner rail walls 9 and slots 17 of the 
frame rail members in and against which the side panels 12 may be 
supported and removably secured. Cutouts 52 similar in function to the 
cutouts 29 are formed in the clips 37 to accommodate their insertion into 
the slots 18. The winged portion 40 include holes 41 in order that the 
side panels 12 may be secured thereto by means of an appropriate fastener. 
From the foregoing, it will be appreciated that a simple parallelepiped 
electronic enclosure 10 may quickly and easily be assembled utilizing a 
plurality of panel mounting clips 37, which may be pre-assembled to 
pe-selected frame rail members 11; eight corner connector clips 19; six 
wall panels 12; and one or more shelf panels 46. 
The electronic equipment enclosure disclosed herein provides an extremely 
practical means for enclosing and protecting electronic equipment and 
similar apparatus. Its various features facilitate easy and inexpensive 
assembly and afford great versatility for its intended use. While the 
particular enclosure described herein is a preferred embodiment of this 
invention, the invention is not limited to this particular arrangement 
and, as will be appreciated and understood by those skilled in the art, 
changes may be made without departing from the scope of the invention 
which is defined in the appended claims.