Interlocking stackable housing structure

A surgical accessory equipment housing having mounting pads at the lower corners which permit stacking of a plurality of such housings by serving as a non-slip support for the bottom housing and as an interlocked spacer between the stacked housings. Each pad has a right angular foot which engages the upper corner of a subjacent housing with spacer ribs disposed between the housings. The bottom housing rests on a flat surface, supported by the four feet of its mounting pads.

This invention relates to surgical equipment and in particular to housings 
for that equipment so constructed as to be interfittable one with another 
in a stack. 
Some forms of surgery, particularly on the abdomen and within the urinary 
tract, are aided by sophisticated, unitized equipment including 
insufflators for introducing CO.sub.2 into the abdomen (to distend the 
internal organs), high energy sources for electrosurgical instruments 
employed in resection and coagulation, fiber optic light sources for 
endoscopy, and so on. 
The units, when made separately and confined in separate housings, are 
usually allocated to separate stands or shelves in the operating room. 
This may require repeated handling of each unit but more worrisome is the 
plain fact that there may be too much crowding. 
It has been proposed to combine several of the functional units in a 
single, "duplex" housing. There are two difficulties with that. 
One difficulty is that the units themselves are expensive, meaning the 
manufacturer has an expensive inventory to maintain. This problem is 
exacerbated when a hospital may find itself duplicating an existing 
function in order to acquire a new one incorporated in the "duplex" 
housing. The hospital can acquire the new function only along with the one 
already available at the hospital. Also, if only one of the units in the 
"duplex" housing requires servicing both functions become unavailable if 
the housing has to be removed from the operating room. 
The other difficulty with combined units is the hospital may more often 
than not need prompt action when it comes to servicing. Expedited 
transportation is required, even air express sometimes, but both public 
and private express services place a limit on the weight they will handle. 
Combined units are apt to exceed such limits. 
The object of the present invention is to overcome the difficulties just 
mentioned by constructing separate housings for the individual functions, 
that may be easily stacked atop one another in an interlock relation 
without apprehension of relative displacement. Specifically an object of 
the present invention is to construct symmetrical housings, housing the 
functional equipment required in the operating room, so that the four 
lower corners of an upper housing may be anchored to the four upper 
corners of a subjacent housing, while at the same time assuring the bottom 
housing will stay in place when set on a table serving as a support for 
the housings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows an exploded view of a stack 10 of two surgical accessory 
housings. These housings enclose equipment of the type described above. 
For example, the bottom unit 12 could be a high energy generator for 
electrosurgery while the top unit 14 could be insufflation equipment. The 
stack is designed to accommodate a third or even a fourth unit if 
necessary, but for convenience these are not shown as the invention can be 
described by the two-unit stack. The position of the units in the stack is 
not critical. The mounting pad of this invention permits stacking them in 
any desired order. 
Each surgical accessory unit has a housing 16 which is generally of the 
shape of a rectangular box or parallelepiped. The housing is formed by 
joining together appropriately-sized metal stampings. The instrument panel 
18 is at the front of the housing and has a series of apertures 20 for 
receiving the switches, dials and gauges of the particular unit. These 
switches and dials are not shown in the drawing. As seen in FIG. 2, the 
bottom panel 22 and back panel 24 have their edges folded to form flanges 
25 which provide joining surfaces for fitting the panels together. This 
can be done by spot welding or other suitable means. The instrument panel 
18 is similarly connected to the bottom panel. A one-piece cover 26 
presents the top and side walls of the housing. The cover is attached to 
the bottom, back and instrument panels by screws 28. This configuration 
provides three-sided access to the inside of the unit should servicing be 
required. 
The cover 26 does not make a square, flush corner at the upper edge of the 
instrument panel 18. Rather, the cover extends forwardly beyond the plane 
of the front panel to form a projecting hood 30. The side panels of the 
cover are angled at the front edge so that the extension of the cover 
beyond the face of the instrument panel gradually decreases from the top 
edge toward the bottom. At the bottom corners the side panels are flush 
with the instrument panel 18. This is best seen in the bottom unit 12 at 
32. 
Ordinarily, in an operating room, the electrosurgery and insufflation 
equipment is set on a tilted table so that the dials are easily viewed. 
The tilting puts the instrument panel in line with the surgeon's line of 
sight. The hood 30 helps make the dials easier to read as it tends to 
lessen the glare on the instrument panel. The hood also serves as a 
convenient lifting point when a unit is placed onto or removed from the 
stack. Carrying handles 34 are provided at the front of the unit (not 
shown in the bottom unit 12). There is also a handle on the back panel 24 
(also not shown). 
The lower corners of each housing have fitted thereto pads or feet 36. The 
pads at each of the four corners are all alike. Each pad comprises a metal 
plate 38 engaged with the bottom panel 22. The connection between the pad 
and housing can be made by a bolt 40 and nut 42 combination as shown in 
FIG. 2 or with a self-tapping screw. 
The details of the pad construction can be seen in FIGS. 3, 4 and 5. On the 
underside of the metal plate 38 are downwardly directed reinforcing lugs. 
Two of these lugs 44 extend along the length of adjacent sides of the 
metal plate. At the ends of these lugs are shorter lugs 46 extending along 
the other two sides of the plate 38. An elastomer is molded over both the 
long lugs 44 and the shorter ones 46. So covered, the long lugs 44 form a 
continuous right angular foot 48 at the bottom of the plate 38. The short 
lugs 46, which only extend about half the distance from the plate as do 
the long lugs 44, become, when covered, spacer ribs 50 at the underside of 
the plate. On the upper side of the plate, which fits against the bottom 
panel 22, the molded elastomer extends to form a right angular guide 52 
which embraces the corner of the housing. 
The pads on the bottom unit 12 serve as nonslip supports for the stack 10. 
As can be seen in FIG. 3, the stack rests on the right angular foot 48 of 
each of the four pads. 
The housing of the upper unit rests on the spacer ribs 50 of the pads. This 
is because the right angular foot is so located as to fit around the 
corner of the subjacent unit rather than on it. It can be seen that since 
the guide 52 encloses the lower corner of the housing, the right angular 
foot 48 will also envelop the corner of the like-sized housing of the 
lower unit. Slots 54 are cut in the hood 30 to provide clearance for the 
portion of the right angular foot 48 that would otherwise contact the 
hood. The upper units then rest on the spacer ribs 50 with the right 
angular feet 48 embracing the corners of the subjacent unit to provide an 
interlocked support between the units.