Abstract:
The invention features implementation of a flat triangular blade which haswo cutting edges and a sharp point. The blade is caused to move pointwise across a cylindrical can&#39;s diameter, with the plane of the blade perpendicular to the can&#39;s axis, so that the point pierces the can, the two cutting edges slice through the can in both directions around the can&#39;s circumference, and the point again, diametrically oppositely, pierces the can. The inventive removal of the residual contents and propellants from a spent aerosol can is optimally effective, because the invention divides the can into two separate parts, concomitantly subdividing the can&#39;s internal components.

Description:
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to methods and apparatuses for penetrating containers, more particularly to such methods and apparatuses which are used for hazard abatement of aerosol container refuse. 
     Many commercially available substances (e.g., paints, insecticides, detergents, etc.) are packaged under pressure in conjunction with a gaseous propellant so as to be releasable as an aerosol. Aerosol containers (commonly referred to as aerosol &#34;cans&#34;) present a potentially hazardous condition because of their pressurized flammable contents. 
     Often the need arises for expellation of the residual contents of used, spent and defective aerosol containers, so as to reduce hazards associated with their storage or disposal. Specifically, a container which has not been completely depressured and/or which has not been completely evacuated of liquid and/or gaseous residue may represent a perilous situation in terms of flammability, toxicity and explosiveness. 
     Conventional approaches to depressurizing the contents of a waste aerosol container have involved puncturing of the aerosol container. Conventional devices release the pressure held within the container by forcing a pointed object through the container wall, thereby producing a permanent hole. 
     These conventional processing methodologies are not entirely effective for processing aerosol containers, especially containers of more recent vintage. Conventional container processing often does not allow for complete drainage of the aerosol container&#39;s liquid contents; the liquid contents may not be provided adequate pathways to escape under gravitational forces. Furthermore, conventional processing approaches often fail to release all the propellant gases that are contained in the aerosol; escape of propellant gases from the single puncture hole may be unacceptably slow, perhaps even practically nonexistent. Moreover, the latest design containers have internal components which may obstruct complete processing when conventional methods are used. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide method and apparatus for accomplishing as complete removal as possible of the residual contents and propellants from aerosol containers which are no longer intended for or suitable for use, in order that such containers can safely be stored or discarded. 
     It is another object of this invention to provide such method and apparatus which are efficient and practical. 
     The present invention provides method and apparatus for severing an object. The object is of a type having an exterior wall which is configured for effecting containment, e.g., an aerosol container. According to the invention, the object is held in place. A substantially planar blade, which includes a substantially triangular portion having two angled edges and a vertex tip, is carried transversely with respect to the object, whereby the blade tip punctures the object wall at two locations and the two blade edges slice the object wall between the two locations. 
     Many embodiments of this invention provide apparatus for dividing a structure which includes a closed peripheral section. The apparatus comprises a holder for the structure, a substantially flat blade, and a carriage mechanism for the blade. The blade has two oblique knife edges and a sharp tip at the junction of the edges. The blade approximately defines an imaginary plane. The carriage mechanism orients the blade with the tip toward the closed peripheral section whereby an imaginary closed peripheral line is formed in the closed peripheral section by the intersection of the closed peripheral section with the imaginary plane. The carriage mechanism provides approximately linear movability of the blade within the imaginary plane and across the closed peripheral section. 
     The present invention features implementation of a flat triangularly shaped blade whereby the blade travels in an essentially linear direction in the plane of the blade and thereby effects division of a single container into two separate container parts. The inventive processing thus advantageously accomplishes a &#34;large scale destruction&#34; of the container, thereby furthering depressurization and fluid evacuation (both liquid and gaseous) of the container. By inventively severing the container into two pieces, the invention serves to afford sufficient pathways for complete evacuation of the container; in particular, the invention serves to break apart all internal container mechanisms which, if left intact, could impede depressurization or evacuation. 
     In other words, the invention not only divides the container but also subdivides all internal components which could hinder or thwart the usual objectives of aerosol container processing. By contrast, conventional processing techniques permit internal container components to remain in place, thereby permitting retention of internal pressure, residual fluid contents and/or propellant gases. 
     For many inventive embodiments the container-severance procedure includes the following: The triangular blade punctures the container a first time, then effectuates bilateral bidirectional perimetric (e.g., circumferential) slicing, then punctures the container a second time, and then effectuates bilateral quadridirectional perimetric (e.g., circumferential) slicing, whereupon complete separation ensues. 
     Many inventive embodiments purposely benefit from geometrical symmetry both of the blade and of the container. Inventive embodiments having these symmetrical qualities especially manifest, to great advantage, a type of bilateral synchronism of the inventive severance procedure. According to such embodiments, with some degree of approximation, an isosceles blade (i.e., having two equal knife edges) is utilized in geometrically complementary fashion for bisectingly processing a cylindrical container. 
     In accordance with inventive embodiments wherein an isosceles blade is used for dividing a cylindrical container, the isosceles blade travels, with the point of the blade frontward, in a direction which is coincident with the blade&#39;s bisector and the cylindrical container&#39;s diameter and which is perpendicular to the container&#39;s longitudinal axis, so that the following sequence occurs: The point of the blade perforates the container at a first location; in virtual concurrence, the blade&#39;s two knife edges bilaterally cut through the container, around the container&#39;s perimeter, in two opposite downward circumferential directions (i.e., with the first knife edge cutting downwardly counterclockwise and the second knife edge cutting downwardly clockwise); the point of the blade perforates the container at a second location which diametrically opposes the first location; in virtual concurrence, the blade&#39;s two knife edges bilaterally cut through the container, around the container&#39;s perimeter, in two opposite downward circumferential directions and in two opposite upward circumferential directions (i.e., with the first knife edge cutting both downwardly counterclockwise and upwardly clockwise, and with the second knife edge cutting both downwardly clockwise and upwardly counterclockwise); and, in virtual concurrence, the first knife edge&#39;s downwardly counterclockwise cutting and upwardly clockwise cutting converge (i.e., approach and meet), and the second knife edge&#39;s downwardly clockwise cutting and upwardly counterclockwise cutting converge (i.e., approach and meet), thereby effecting complete severance of the container. 
     The vectorial forces of the cutting actions of the knife edges are not strictly aligned with the perimetric path but, rather, have admixtures of transverse and perimetric force components. These forces are inventively availed so as to largely preserve the integrity of the aerosol container&#39;s shape. Total or substantial collapse of an aerosol container would be undesirable because it would hamper escape of the fluid contents. The present invention substantially avoids collapse of the container wall but permits a beneficial degree of deformation of the container wall. 
     In an earlier phase of the inventive severence procedure (i.e., following the first puncturing of the container wall), the opposing cutting forces associated with the bidirectional circumferential cutting actions threaten to collapse the container wall; this is because these forces, acting in the diametrically upper vicinity of the container, are not being supported or counterbalanced by forces in the diametrically lower vicinity of the container. In a latter phase of the inventive severence procedure (i.e., following the second puncturing of the container wall), the opposing cutting forces associated with the quadridirectional circumferential cutting actions act in concert; the opposing cutting forces tend to cancel out one another sufficiently to reduce or curtail cave-in of the container wall. 
     At the same time, the small degree of container wall deformation which accompanies the inventive severence procedure may assist the expedient escape of gases, especially from containers of more modern design which have an internal plunger working directly against the internal contents. Hence, in the invention&#39;s uniquely efficacious manner, the synergistic combination of the blade&#39;s triangularity, the container&#39;s cylindricality and the blade-vis-a-vis-container severing activity serves to minimize but not entirely eliminate the shape deformation of the aerosol container. Inventive embodiments characterized by symmetrical geometry of blade and container particularly enjoy the attendant advantages. 
     The inventive synergy of the blade&#39;s triangular shape acting upon the container&#39;s cylindrical shape promotes the ease and effectiveness of the blade&#39;s cutting action. The triangular blade&#39;s tip essentially presents a small frontal area which facilitates both the initial and final perforations. As the blade travels between the blade tip&#39;s initial and final perforations, the blades triangularity progressively subjects the container wall to an increasing blade width. This progressive increase in blade width is associated with a tendency of the blade to cut the container&#39;s wall with bilaterally paired side force components (i.e., in paired outwardly sideways directions) in addition to bilaterally paired perimetric force components (i.e., in paired directions of perimetric travel). 
     According to many inventive embodiments, there is a trigonometric relationship between the magnitude of the triangular blade&#39;s &#34;inclusive angle&#34; (i.e., the angle formed by the two knife edge line segments meeting at the tip vertex) and the rate at which the blade width changes in relation to the container. The magnitude of the blade&#39;s inclusive angle may affect the degrees and proportions of the transverse and perimetric force components which accompany the blade&#39;s cutting activity. In addition, when the blade effectuates bilateral quadridirectional circumferential slicing, there eventually is convergence of the first knife edge&#39;s downwardly counterclockwise cutting and upwardly clockwise cutting, as well as convergence of the second knife edge&#39;s downwardly clockwise cutting and upwardly counterclockwise cutting; the locations of these two cutting convergences (i.e., meetings) vary in accordance with the blade&#39;s inclusive angle. Accordingly, the inventive blade&#39;s inclusive angle is a variable parameter which, in the light of the teachings herein, the ordinarily skilled artisan who practices this invention can optimize depending upon the requirements for a particular application. 
     In accordance with the principles of this invention, the fluid contents having liquid characteristic will gravitationally drain from the container, and the fluid contents having gaseous characteristic (e.g., propellant gases) will escape from the container. For most inventive embodiments it is preferable that the liquid and gaseous emissions each be separately collected in auxiliary containment apparatus so as to prevent environmental exposure. Rather than be permitted to diffuse amidst the surroundings, the liquid emissions should be drained into a receptacle, and the gaseous emissions should be captured by any of various techniques known to the ordinarily skilled artisan. In exceptional situations the gaseous emissions may perhaps be permitted to be diluted with the surrounding atmosphere, provided that such would not be illegal and the deleterious effects would be virtually nonexistent; in general, however, such is considered imprudent for inventive practice. A cavalier attitude toward disposition of the liquid and gaseous emissions from aerosol containers is condemned and discouraged. 
     Many inventive embodiments take advantage of the physical laws of gravitation. According to such embodiments, the blade is oriented vertically and the container is oriented horizontally so that, upon completion of the blade&#39;s severance of the container, drainage of the container&#39;s liquidly flowing contents is facilitated. 
     Other objects, advantages and features of this invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the present invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawing, wherein like numbers indicate the same or similar components, and wherein: 
     FIG. 1 through FIG. 4 diagrammatically illustrate severance of a container by a blade in accordance with the present invention. 
     FIG. 5 is a diagrammatic perspective view of an inventive embodiment. 
     FIG. 6 is a diagrammatic side elevation view of another inventive embodiment. 
     FIG. 7 is a diagrammatic end elevation view of the inventive embodiment shown in FIG. 6. 
     FIG. 8 is a diagrammatic view of the inventive embodiment shown in FIG. 6, similar to to view shown in FIG. 6 but partially in cross section to show some interior detail. 
     FIG. 9 is a diagrammatic view of the inventive embodiment shown in FIG. 6, similar to to view shown in FIG. 7 but partially in cross section to show some interior detail. 
     FIG. 10 is a diagrammatic top plan view of an inventive embodiment which is similar to the inventive embodiment shown in FIG. 6. 
     FIG. 11 is a diagrammatic view of the inventive embodiment shown in FIG. 10, similar to to view of the inventive embodiment shown in FIG. 6. 
     FIG. 12 is a diagrammatic view of the inventive embodiment shown in FIG. 10, similar to to view of the inventive embodiment shown in FIG. 7. 
     FIG. 13 is an enlarged diagrammatic elevation view, similar in perspective to the view shown in FIG. 12, of the blade assembly for the inventive embodiment shown in FIG. 10. 
     FIG. 14 is an enlarged diagrammatic view, similar in perspective to the view shown in FIG. 13, of the blade for the blade assembly shown in FIG. 13. 
     FIG. 15 is an edgewise diagrammatic elevation view of the blade shown in FIG. 14. 
     FIG. 16 is an enlarged diagrammatic partial elevation view, similar in perspective to the view shown in FIG. 12, of the holding chamber for the inventive embodiment shown in FIG. 10. 
     FIG. 17 is an enlarged diagrammatic plan view, similar in perspective to the view shown in FIG. 10, of one of the two blade guides for the inventive embodiment shown in FIG. 10. 
     FIG. 18 is a diagrammatic elevation view, similar in perspective to the view shown in FIG. 11, of the blade guide shown in FIG. 17. 
     FIG. 19 is a diagrammatic elevation view, similar in perspective to the view shown in FIG. 12, of the blade guide shown in FIG. 17. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIG. 1, vertical flat metallic blade 18 is situated directly above horizontal cylindroid aerosol container 20 and is poised for penetration. Blade 18 has two smooth knife edges, viz., lefthand edge 22 L  and righthand edge 22 R , which meet at piercingly sharp tip 24 and thereby form inclusive angle s. Container 20 has cylindrical side wall 26, which appears as a circle in FIG. 1. Wall 26 is symmetrical with respect to the longitudinal axis a of container 20. Longitudinal axis a appears as a center point in FIG. 1. The slight projection of tip 24 in the plane of blade 18 serves to facilitate puncturing of wall 26 by tip 24. 
     Horizontal dashed line segment w indicates the base of the blade&#39;s isosceles triangular portion t formed by segment w and equal edges 22 L  and 22 R . Segment w also corresponds to the width of blade 18, which exeeds the diameter, indicated by dashed line segment d, of container 20. Inclusive angle s is ninety degrees and knife edges 22 L  and 22 R  are equal; hence, blade portion t is an isosceles right triangle. 
     The two smooth noncutting vertical blade edges 28 L  and 28 R  are equal, opposite and parallel and, together with segment w and horizontal upper blade edge 30, form rectangle r which is immediately vertically adjacent to triangle t. The rectangular configuration of upper blade portion r, in particular, the verticality of edges 28 L  and 28 R , lend blade 18 to sliding engagement with two vertical grooved blade guides such as shown in FIG. 17 through FIG. 19. For such inventive embodiments, it is preferable that the blade and the blade guides each be made of a non-sparking metallic material. 
     Dashed vertical bisector line b bisects blade 18--i.e., bisects both rectangle r and triangle t. In addition, the perpendicular vertical plane through line b (i.e., perpendicular to blade 18) not only bisects blade 18 but also diametrically passes through longitudinal axis a and thereby axially bisects cylindrical side wall 26. 
     Mechanical actuator 32 is coupled with blade 18, for example by means of fasteners 52. Still with reference to FIG. 1 and also with reference to FIG. 2 through FIG. 4, the invention is basically effectuated by exerting a vertically downward vectorial force f upon blade 18 by means of mechanical actuator 32 such as will cause blade 18 to move vertically downward through cylinder 20 in the direction coincidental with bisector line b. For most inventive embodiments, force f is either humanly driven or electrically driven. 
     Tip 24 is shown in FIG. 2 contiguously verging on puncturing side wall 26 at location l 1 . The pressure in container 20 begins to be released as tip 24 punctures a hole in side wall 26. As blade 18 continues to proceed downward, cutting edges 22 L  and 22 R  are in bidirectional mode; cutting edges 22 L  and 22 R  slice through side wall 26 in virtual simultaneity in two opposite circumferential directions (i.e., righthand edge 22 R  slicing wall 26 downwardly clockwise as shown by curved arrow DN CW  in FIG. 2; lefthand edge  22  L slicing wall 26 downwardly counterclockwise as shown by curved arrow DN CCKW  in FIG. 2). The container 20 pressure is increasingly released as blade 18 is slowly, steadily and forcibly advanced through side wall 26. The fluid contents may also increasingly seep as blade 18 increasingly penetrates. 
     By continuing to force blade 18 vertically across the diameter d of container 20 in this manner, the operator will soon succeed in sectioning container 20 into two parts. Tip 24 is shown in FIG. 3 verging on puncturing side wall 26 at location l 1  2, which is diametrically opposite location l 1 . The inventive processing nears completion as tip 24 punctures a hole in side wall 26 at location l 2 . 
     Cutting edges 22 are now in quadridirectional mode; cutting edges 22 L  and 22 R  slice through side wall 26 in virtual simultaneity in two pairs of opposite circumferential directions i.e., righthand edge 22 R  slicing wall 26 downwardly clockwise as shown by curved arrow DN CW  in FIG. 2, and upwardly counterclockwise as shown by curved arrow UP CCKW  in FIG. 2; lefthand edge 22 L  slicing wall 26 downwardly counterclockwise as shown by curved arrow DN CCKW  in FIG. 2, and upwardly clockwise as shown by curved arrow UP CW  in FIG. 2). Soon there is a convergence c L , at the lefthand side of container 20, of the downwardly counterclockwise cutting and upwardly clockwise cutting by lefthand cutting edge 22 L , as well as a convergence c R , at the righthand side of container 20, of the downwardly clockwise cutting and upwardly counterclockwise cutting by righthand cutting edge 22 R . 
     The locations of the two cutting convergences c L  and c R  are a function of the magnitude of inclusive angle s. As shown in FIG. 3, right angle s yields convergences c L  and c R  which are each distanced, in the clockwise and counterclockwise directions, respectively, of circular container wall 26, approximately forty-five degrees of arc from location l 2 . 
     Generally with regard to symmetrical inventive embodiments, wherein an isosceles blade 18 is implemented for diametrically bisecting a cylindrical container 20 in accordance with the teachings herein, the arc distances of convergences c L  and c R  from location l 2  are approximately equal and each about equivalently varies in inverse relationship with inclusive angle s; that is, as inclusive angle s increases, each arc distance from location l 2  decreases, and as inclusive angle s decreases, each arc distance from location l 2  increases. 
     The piercing of a hole at location l 2  combines with the continued cutting caused by the ongoing vertically downward movement of blade 18, culminating in realization of convergences c L  and c L  and thus effecting complete separation of container 20 into two container 20 parts. As shown in FIG. 4, blade 18 has completely severed container 20. In so doing, blade 18 has also severed internal components of container 20. 
     At this point blade 18 can be moved vertically upward and thereby withdrawn from container 20. Once blade 18 is withdrawn, the fluid contents and propellants evacuate completely. The liquid evacuation can be redirected into a collection vessel such as receptacle 58 shown in FIG. 6 through FIG. 9. 
     Referring to FIG. 5, blade assembly 34 includes downwardly vertical blade 18 and drill press-type mechanical actuator 32, which includes shaft-like actuator member 36. Blade 18 is attached to shaft-like member 36. The longitudinal axis of horizontally oriented container 20 is orthogonal with respect to the plane of blade 18. Blade 18 is shown to be about at the stage of processing illustrated in FIG. 2. Container-holding frame 38 is a block (e.g., wooden) which has provided therein &#34;V&#34;-shaped notch 40, for horizontal placement of container 20, and slot 42, for vertical movement of blade 18. Inventive processing apparatus 44 shown in FIG. 5, representative of an initial breadboard tested by the U.S. Navy, thus comprises separate blade-mechanism and container-holding units. 
     Reference now being made to FIG. 6 through FIG. 9, inventive processing device 44 is a single unit which includes blade assembly 34, vertical blade-mechanism housing 46 and hollow cylindrical horizontal container-holding chamber 38. As shown in FIG. 9, housing 46 interiorly includes two nonsparking metallic vertical blade guides 48. Blade assembly 34 includes downwardly vertical blade 18 and manually operable mechanical actuator 32. Actuator 32 has vertical shaft-like member 36 and horizontal handle 50 at the upper end of shaft-like member 36. One or more fasteners 52 are for attachment of actuator 32 to blade 18 at the lower end of shaft-like member 36. Each of the two vertical edges 28 of nonsparking metallic blade 18 slidably engages one of the two vertical blade guides 48. 
     Chamber 38 is for holding container 20 in a horizontal position. The longitudinal axis of container 20 is orthogonal with respect to the plane of blade 18. The operator actuates device 44 for processing of container 20 by manually exerting a downward vertical force f on handle 50. Blade 18 is shown in FIG. 8 and FIG. 9 to be about at the stage of processing illustrated in FIG. 2. 
     Inventive device 44 is bifurcated along the imaginary horizontal longitudinal axial plane h of chamber 38 into upper inventive device section 44u and lower inventive device section 44l. Upper inventive device section 44u includes upper semicylindrical chamber section 38u; lower inventive device section 44l includes lower semicylindrical chamber section 38l. One or more hinges 54 join upper semicylindrical chamber section 38u with lower semicylindrical chamber section 38u so as to permit pivotably arcuate motion p of upper semicylindrical chamber section 38u (and hence, upper inventive device section 44u) away from or toward lower semicylindrical chamber section 38l (and hence, lower inventive device section 44l), thereby enabling pre-processing placement and post-processing removal of container 20. One or more latches 56 secure closure of upper semicylindrical chamber section 38u with respect to lower inventive device section 44l. 
     Inventive device 44 is mounted upon receptacle 58 via connector 60 and support foot 62. As indicated by drainage arrow e, receptacle 58, e.g., an industrial standard 5, 30 or 55 gallon drum, receives the effluent which has drained from processed container 20 and has been guided by inventive device 44. 
     With reference to FIG. 10 through FIG. 19, a metallic prototype of inventive processing device 44, based on inventive processing device 44 shown in FIG. 6 through FIG. 9, has successfully been designed and tested by the U.S. Navy. The inventive processing device 44 prototype shown in FIG. 10 through FIG. 19 is mostly made of steel and bronze parts and materials. The approximate dimensions of the inventive processing device 44 prototype, as represented in FIG. 10 through FIG. 12, are length L=17.75 inches, width W=6.25 inches, extended height H=20.25 inches. 
     Blade assembly 34 shown in FIG. 13 has an approximate length B=11.42 inches. Blade 18 shown in FIG. 14 and FIG. 15 has an approximate width K W  =3.24 to 3.25 inches. Each noncutting vertical blade edge 28 has a length K L1  of approximately 2.13 to 2.14 inches. Each fastener 52 is approximately a distance F=0.28 from horizontal upper blade edge 30. Each cutting blade edge 22 has a length E L  of approximately 2.29 to 2.30 inches. Inclusive angle s is approximately ninety degrees. 
     Tip 14 of flat blade 18 extends to tip extremity x a distance P approximately 0.25 inches downward from the vertex v of the inner demarcations 22i of cutting edges 22. The distance K L2  between horizontal upper blade edge 30 and vertex v is approximately 3.63 to 3.64 inches. The distance K L3  between horizontal upper blade edge 30 and extremity x is approximately 3.88 inches. 
     The width E P  of each cutting edge 22, in terms of in-plane distance between inner demarcation 22i and outer demarcation 22 o , is approximately 0.06 inches. The thickness T of blade 18 is approximately 0.13 inches. The width E T  of each cutting edge 22, in terms of through-plane distance between inner demarcation 22i and outer demarcation 22 o , is approximately 0.06 inches. 
     Hollow cylindrical chamber 38, represented in FIG. 16 as having an inner radius R of approximately 1.63 inches, is especially suitable for holding similarly curvilinearly contoured aerosol containers 20 and is spacious enough to accommodate most conventional aerosol containers 20. In accordance with the teachings herein, many different embodiments of this invention can be practiced for processing aerosol containers 20 of varying sizes and shapes. 
     As illustrated in FIG. 17 through FIG. 19, each of two grooved blade guides 48 has a length G L  approximately equal to 6.25 inches, a width G W  approximately equal to 1.24 inches, a total depth G T  approximately equal to 1.00 inch, a groove width g W  approximately equal to 0.13 inches, and a groove depth g T  approximately equal to 0.13 inches. 
     Other embodiments of this invention will be apparent to those skilled in the art from a consideration of this specification or practice of the invention disclosed herein. Various omissions, modifications and changes to the principles described may be made by one skilled in the art without departing from the true scope and spirit of the invention which is indicated by the following claims.