Clamp for elastomeric bags

A clamp for thin-walled elastomeric waste collection bags including a molded thermoplastic body with opposed elongate clamping legs. Each leg mounts an elongate rigid blade having a linear edge. The linear edges of the blades align to opposite sides of the bag material as the clamp is closed thereon.

BACKGROUND OF THE INVENTION 
Elastomeric bags, particularly of the type used to collect body wastes such 
as fecal matter, will, if reusable, include a bag emptying opening formed 
at the lower end thereof, preferably in a spout-like depending portion. 
This opening is sealed by a clamp which allows opening of the bag for 
emptying of the contents, and a resealing of the bag for continued use. 
A variety of such clamps have been proposed wherein the clamp is molded of 
an appropriate plastic and includes a pair of elongate legs joined by a 
living hinge at one end and including some form of releasable latch means 
at the other end, the bag, about the opening, being clamped between the 
legs. 
Examples of such clamps will be noted in U.S. Pat. Nos. 4,551,888; 
4,834,730 and 5,125,133. 
The formation of such clamps of plastic, that is a thermoplastic or 
synthetic resinous material, is particularly desirable in that the clamp 
can be inexpensively molded as a one-piece item with an integral hinge and 
latch. The clamps so formed are usually intended for reuse. 
However, elastomeric materials of the type used in the formation of 
thin-walled fecal collection bags and the like give rise to special 
problems. For example, such elastomeric bag materials, by their very 
nature, provide a substantial resistance to clamping forces. Because of 
this resistance or reacting force, the clamp itself must be sufficiently 
stiff so as to avoid any flexure as might allow leakage. The known clamps 
have not been noted as being of such stiffness or rigidity and are not, 
particularly after repeated use, considered very effective in retaining a 
seal. 
In one form of known clamp, a grooved or female locking part is provided 
within which the elastomeric material is clamped by a male member. 
However, because of the nature of the elastomeric materials, it is 
difficult to press the materials into and in conformance with the cavity 
of the female locking part. Further, most elastomers have a high 
coefficient of friction which causes "pulling" problems when they are 
forced into a cavity. 
Thus, while molded one-piece clamps include the advantages of being 
inexpensive to fabricate and capable of being reused several times, the 
actual sealing capabilities of the known clamps, particularly as with 
regard to elastomeric materials of the type used in human waste collection 
bags, are less than completely effective. 
SUMMARY OF THE INVENTION 
The clamp comprising the present invention includes all of the desirable 
features of known clamps in that it comprises an inexpensive molded body 
wherein the two clamping legs are interconnected by a hinge, preferably an 
integral living hinge, at one end and by a releasable molded latch 
assembly at the opposite end. 
However, the improved clamp of the invention, to accommodate the nature of 
the elastic materials of the bags, differs from conventional clamps by 
providing a symmetrical or identical sealing effect by both of the 
clamping legs to both sides of and against both sides of the material 
being clamped. This sealing action effects a positive male part-against 
male part action as opposed to the heretofore actions of such collection 
bag clamps relying on an opposed groove and male part or blade, a male 
part and an opposed flat surface, and the like. 
The clamp of the invention, rather than attempting to conform the 
elastomeric material to a cavity or female part, or merely press the 
layers of material in intimate contact with each other, specifically 
penetrates the wall thickness. That is, in addition to bringing the walls 
in intimate contact with each other, the clamp also, through opposed line 
contact, compresses the wall thicknesses. Thus any tendency for relative 
movement of the clamped walls, or "pulling" problems, which are normally 
inherent because of the nature of the elastomeric materials, are avoided. 
The advantages of the invention are achieved by providing the opposed 
clamping legs with elongate stiff or non-flexing blades, preferably of 
metal. Such blades, for example of stainless steel, form opposed male 
parts with linear outer edges which, in the closed position of the clamp, 
are in a common plane and extend in slightly spaced parallel relation to 
each other. 
The provision of such blades eliminates the problems associated with the 
inherent flexibility of the plastic material of the prior art clamps, 
while at the same time retaining the advantages thereof with regard to an 
inexpensive molded construction with integral hinges and latches. 
The outer or exposed edges of the blades are slightly rounded to avoid any 
tendency to cut or otherwise damage the bag material. Further, the 
transverse spacing between these opposed parallel edges in the closed 
clamp is to be substantially less than the combined thicknesses of the bag 
walls to be clamped thereby. In this manner, the walls are both brought 
into intimate engagement with each other and individually and 
significantly compressed, without cutting, by the blade edges to avoid any 
creeping or relative movement between the bag layers. 
Other features, objects and advantages of the invention will become 
apparent from the more detailed discussion of the invention presented 
hereinafter.

DESCRIPTION OF PREFERRED EMBODIMENT 
Referring now more specifically to the drawings, the clamp 10 includes a 
molded body of plastic, that is synthetic resinous or thermoplastic 
material, comprising a pair of elongate legs 12 and 14 joined at first 
inner ends thereof by a hinge, preferably an integral living hinge 16. 
Each of the legs 12 and 14 has a planar inner face or surface, 18 and 20 
respectively, along at least substantially the full length thereof. 
The leg 14, adjacent the second outer end 22 thereof, has an integral guide 
pin 24 projecting perpendicular from the planar inner face 20 thereof on 
the longitudinal center line of the face. A corresponding socket 26, 
within the leg 12 and opening inwardly through the inner face 18 thereof, 
is similarly located and positioned to receive the guide pin 24 as the 
legs 12 and 14 are closed on each other. The length of the guide pin 24 
and the depth of the socket 26 are such whereby with the guide pin fully 
seated, as illustrated in FIG. 5, the opposed leg faces 18 and 20 are 
positioned in spaced parallel relation to each other with the legs 12 and 
14 transversely aligned. The relative sizes of the guide pin 24 and socket 
26 are such as to provide for a snug interfit whereby lateral and 
longitudinal shifting between the legs is precluded. 
In order to assist in maintaining the parallel relationship between the 
inner surfaces 18 and 20 for the full length of the overlying coextensive 
legs, each leg, adjacent the hinged inner end thereof, includes an 
integral abutment block 28 having a planar inner face 30 which parallels 
the corresponding inner surface 18 or 20 and which, in the closed clamp as 
in FIG. 5, abut each other as the guide pin 24 fully seats within the 
socket 26. 
The actual clamping force to be applied to the elastomeric material of the 
bag 32 is effected by a pair of opposed rigid blades 34 and 36, preferably 
metal, and particularly stainless steel. The blades 34 and 36 are 
permanently affixed to the legs 12 and 14 respectively, with the legs 
preferably molded to the blades. 
The blade 34 extends along the longitudinal center line of the leg 12 and 
projects from the planar inner surface 18 thereof from the inner end 
abutment block 28 to the pin-receiving socket 26. The blade 36, similarly 
along the longitudinal center line of leg 14, projects from the inner 
surface 20 thereof and extends longitudinally between the inner end 
abutment block 28 and the guide pin 24. 
The blades 34 and 36 terminate in linear slightly rounded inner edges 38 
and 40 respectively. These inner edges 38 and 40 are of a height, from the 
corresponding inner leg surfaces 18 and 20, slightly less than that of the 
corresponding abutment blocks 28 whereby, in the closed position of the 
clamp as in FIG. 5, the inner edges 38 and 40 are in a slightly spaced, 
laterally aligned, parallel relation to each other. This spacing, noting 
the sectional detail of FIG. 2, is substantially less than the combined 
thicknesses of the layers of material of the bag 32 which are to be 
clamped whereby the layers of material are not only brought into close 
engagement with each other, but are actually individually compressed to a 
substantial degree. 
In order to lock the clamp in its closed position, a latch assembly is 
provided. The latch assembly comprises a longitudinally extending lug 42 
projecting integrally from the free outer end 22 of leg 14 and including 
an enlarged bulbous or undercut head portion 44 thereon outward of the leg 
end 22. The latch assembly also includes an elongate latch 46 hinged to 
the free second or outer end of the leg 12 by hinge 48, preferably an 
integral living hinge, for selective movement, in the closed position of 
the clamp, into locking engagement with the lug 42. The latch 46 includes 
an inner face 50 having an undercut socket or recess 52 therein which is 
so oriented as to, upon alignment with the lug 42, snap lock over the 
bulbous or enlarged head 44 thereof. It will be noted that the latch 46 is 
turned at approximately right angles to the leg 12 when engaged with the 
lug 42. As such, any force of the compressed bag material acting against 
the clamping force will merely enhance the latch and lug engagement. 
Disengagement of the latch will require a positive manual force acting 
laterally against the latch 46 longitudinally outward of the closed legs. 
In this manner, any accidental disengagement of the clip is precluded. It 
will of course be appreciated that the specific configuration of the 
recess 52 and lug 42, and particularly the undercut portions thereof, are 
such as to, through the inherent flexibility of the material of the 
plastic body, snap lock and snap release upon appropriate manual pressure. 
Further, and noting FIG. 5, the latch interlock is effected when the legs 
are in their closed position with the inner edges 38 and 40 of the blades 
parallel and with the guide pin 24 and abutment faces 30 fully seated. 
Referring again to FIG. 2, in the closed and locked clamp, the inner 
clamping edges 38 and 40 of the rigid blades 34 and 36, are co-planar or 
in direct opposed alignment to provide coextensive male or line engagement 
at directly opposed lines along the length of material being clamped. This 
alignment is facilitated by the socket receive guide pin 24. Further, the 
transverse distance between these edges 38 and 40, being substantially 
less than the combined thicknesses of the material of the bag being 
clamped, effect not only an intimate engagement of the material layers 
together, but also an actual deforming of the walls and a substantial 
reduction of the wall thicknesses along the narrow line of contact. This 
effect is assured by the stiff or rigid nature of the blades which 
preclude any flexing of the clamping blades or blade edges, even after 
repeated uses of the clamp. It is also to be recognized that this line 
clamping and compressing of the bag material, with no flexing of the 
blades or blade edges being possible, eliminates any tendency for the 
elastomeric layers to creep or otherwise shift relative to each other as 
might reduce the sealing effect. 
The combination of such blades, preferably metal, with a thermoplastic 
material body, in the manner described, is of particular significance in 
providing for the desired positive sealing effect achieved by the blades 
while retaining the desirable features of a thermoplastic body, including 
a molded unitary construction, hinges, integral latches, and the like. 
Finally, the actual number of layers of bag material to be clamped will 
depend on the particular nature of the bag. For example, in bag 32 of 
FIGS. 1 and 2, the bag is folded before clamping, thus forming four 
layers. The number of layers will in turn generally dictate the size of 
clamp used and the preferred spacing between the clamping edges 38 and 40 
in the closed clamp. 
The foregoing described embodiment is considered illustrative of the 
invention, and as other embodiments incorporating the inventive features 
may occur to those skilled in the art, the disclosed embodiment is not to 
be considered as a limitation on the scope of the invention. Rather, the 
invention is to only be limited by the scope of the claims following 
hereinafter.