Patent Description:
Screening for explosive materials and illegal narcotics is now routine in airports, train stations, sports arenas, and other locations charged with handling large volumes of individuals. Often, individuals and their belongings must be screened for explosive materials and/or explosive residues. While it is desirable to identify individuals carrying illegal narcotics, it is also important from a security standpoint, to screen individuals for the presence of explosive materials.

<CIT>, on which the preamble of claim <NUM> is based, describes a portable system for the detection of chemical particles such as explosive residue which utilizes a metal fiber substrate that may either be swiped over a subject or placed in a holder in a collection module which can shoot a jet of gas at the subject to dislodge residue, and then draw the air containing the residue into the substrate. The holder is then placed in a detection module, which resistively heats the substrate to evolve the particles, and provides a gas flow to move the particles to a miniature detector in the module. <CIT> discloses a method and system for controllably releasing contaminants from a contaminated porous metallic mesh by thermally desorbing and releasing a selected subset of contaminants from a contaminated mesh by rapidly raising the mesh to a pre-determined temperature step or plateau that has been chosen beforehand to preferentially desorb a particular chemical specie of interest, but not others. <CIT> discloses an apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. <CIT> discloses a portable detection and screening system for the detection of target vapors and/or target particulates that may include explosives, chemical agents, drugs or narcotics, comprising: sampling means for gathering a sample volume of air from a specific area on an individual or object that may contain vapor or particulate emissions of said target materials, said sampling means performing said gathering in a first sampling period, means for concentrating said target vapors or vapors emanating from said target particulates contained in said sample volume of air, said means including means for collecting said target vapors or particulate emissions at a first location; means for transporting said collected target vapors or particulate emissions to a second location distinct from said first location; means for desorbing said target vapors or particulate emissions at said second location in a second sampling period; and, detection means responsive to said target vapors or particulate emissions desorbed at said second location to generate a signal in response to the presence of said target materials in said sample volume, wherein said sampling means is adapted for collecting a new sample volume of air containing target vapors or particulate emissions at said first location during said second sampling period.

One embodiment relates to a cartridge assembly according to claim <NUM>. The mesh of such embodiment may comprise a stainless steel mesh. The cartridge assembly may further comprise a clamping assembly for securing one or more of the scalloped surface or the bus bar into contact with a mesh disposed between the scalloped surface and the bus bar. The cartridge assembly may further comprise another body portion to which the clamping bar is mounted, wherein at least one of the body portion or the other body portion has a concave profile. Here, the body portion and the other body portion may be coupled by a hinge.

Another embodiment relates to a preconcentrator comprising a cartridge assembly according to claim <NUM>, wherein the body portion is configured to be disposed in an airflow, the body portion defining the opening through which at least a portion of the airflow is directed; the preconcentrator comprises an other body portion defining an opening that is configured to align with the opening in the body portion when the other body portion is secured to the body portion; the clamping bar is mounted to at least one of the body portion or the other body portion, the scalloped surface of the clamping bar is configured to at least partially secure the mesh between the body portion and the other body portion, the preconcentrator comprises means for securing the body portion and the other body portion one to another.

Yet another embodiment relates to a screening device comprising a source configured to generate a flow of air through which an object is to pass; and a preconcentrator according to claim <NUM>, disposed in a path of the flow, the preconcentrator being configured to capture particulate matter dislodged from the object by the flow.

Referring to <FIG>, a particle collection device <NUM> (e.g., a cartridge assembly, a mesh cartridge assembly, a preconcentrator, etc.) is shown according to an exemplary embodiment. Particle collection device <NUM> includes a body <NUM> having a first portion or housing <NUM> (e.g., a body portion, a first body portion, a housing, etc.) and a second portion or door <NUM> (e.g., an other body portion, a second body portion, a door or door assembly, etc.). One or more disconnect members <NUM> may be provided to provide electrical connectivity between particle collection device <NUM> and other components. Device <NUM> may include a handle <NUM> configured to facilitate the insertion and/or removal of device <NUM> from another component, such as a screening device, etc. For example, device <NUM> may be a preconcentrator that is used to capture particles, such as particles of narcotics and/or explosive materials, blown off a human passing through a security screening device.

According to embodiments, device <NUM> is configured to be placed in the path of an airflow and capture particles travelling within the airflow. The particle collection device can be used in any suitable instrument or configuration, such as, for example, in walk-through detection equipment (e.g. portals) at security or customs checkpoints. For example, device <NUM> may utilized as part of a screening device (e.g., a portal, etc.) such that air is directed along an air flow <NUM> from an air source <NUM> over and/or past an object (e.g., a person, luggage, etc.) and passes through device <NUM>. Device <NUM> captures particles travelling with the air passing along air flow <NUM> through device <NUM>. Upon being captured by device <NUM>, the particles may be subjected to further analysis (e.g., analysis by a device such as an ion mobility spectrometry (IMS) device, a Fourier transform infrared spectroscopy (FTIR) device, and the like).

Referring to <FIG>, device <NUM> is shown in greater detail in accordance with various embodiments. As shown in <FIG>, housing <NUM> and door <NUM> may be pivotally coupled to one another. For example, one or more hinges <NUM> may be utilized to couple housing <NUM> and door <NUM>. Alternatively, housing <NUM> and door <NUM> may be pivotally coupled without the use of a hinge (e.g., by using one or more "pseudo-hinge" features, pivot rods, or components). According to yet another embodiment, housing <NUM> and door <NUM> may be completely separable and may be coupled utilizing a snap fit, interference fit, or other type of mechanical or other coupling method.

Referring further to <FIG>, housing <NUM> defines an aperture <NUM> that permits air to flow through device <NUM>. According to an embodiment, housing <NUM> is a generally planar member, while in other embodiments housing <NUM> may have a curved (e.g., concave, convex, etc.) profile with an apex extending toward or away from door <NUM>. Although aperture <NUM> is shown as being generally circular in shape, any suitable shape or configuration (e.g., square, rectangular, etc.) may be used in connection with aperture <NUM>. One or more bus bars <NUM> (electrically and/or thermally conductive members, etc.) may be coupled or otherwise supported by housing <NUM>. In other embodiments, one bus bar <NUM> is provided to each of two opposite portions of aperture <NUM>. While bus bars <NUM> are shown as being generally straight, elongated members, other configurations (e.g., curved, irregularly-shaped, etc.) of bus bars may be used, and more or less bus bars than those shown in <FIG> may be utilized.

Door <NUM> defines an aperture <NUM> that permits air passing through aperture <NUM> to completely pass through device <NUM>. In one embodiment, apertures <NUM>, <NUM> are generally aligned when device <NUM> is in a closed or secured position (as shown in <FIG>). As shown in <FIG>, aperture <NUM> may have a generally rectangular shape, while in other embodiments aperture <NUM> may take other shapes and/or configurations (e.g., circular, square, etc.). Both of apertures <NUM>, <NUM> may be sized appropriately to permit for the appropriate airflow through device <NUM>. According to one embodiment, door <NUM> may have a curved (e.g., concave, convex, etc.) profile having an apex extending either toward or away from housing <NUM>. One or both of housing <NUM> and door <NUM> may include one or more supports <NUM> configured to provide additional support to the components of device <NUM>.

In embodiments, device <NUM> may further comprise a mesh <NUM> (e.g., a stainless-steel mesh material or assembly, a filter, screen, wire mesh, etc.). Mesh <NUM> may be placed in the path of the airflow travelling through device <NUM> and be configured to collect particles with traces of target compounds, including but not limited to, narcotic or explosive substances. For example, mesh <NUM> is sized to capture particles of the size of narcotic or explosive particles expected to cling to objects. After the collection of particles is accomplished, heat can be applied to mesh <NUM> to release, e.g., liberate, captured particles, and the resulting vapors can be analyzed using any suitable method, such as, for example ion mobility spectrometry (IMS). As shown in <FIG>, mesh <NUM> may be generally square in shape. According to various other embodiments, mesh <NUM> may be any suitable type and take any suitable shape (e.g., a shape suitable to cover apertures <NUM>, <NUM>, circular, rectangular, etc.). The mesh material may be electrically and/or thermally conductive to facilitate heating of mesh <NUM>, e.g., act as a resistor). For example, a stainless steel mesh is used to capture particles blown off a human at least partially positioned in the air flow. Furthermore, mesh <NUM> may be a removeable/replaceable component of device <NUM>.

Door <NUM> may further include one or more clamping bars <NUM> (e.g., clamping members, bus bars, etc.). In one embodiment, clamping bars <NUM> and bus bars <NUM> generally face one another when door <NUM> is closed such that mesh <NUM> is secured between clamping bars <NUM> and bus bars <NUM>. Clamping bars <NUM> and bus bars <NUM> are in electrical and/or thermal contact with mesh <NUM>. One or more of bus bars <NUM> and/or clamping bars <NUM> are biased toward the other (e.g., via a spring, a curvature in the component profile, etc.) to further increase the retention force on mesh <NUM>. Furthermore, the relative positions of bus bars <NUM> and clamping bars <NUM> may be reversed in some embodiments. In some embodiments, bus bars <NUM> and clamping bars <NUM> are configured to retain mesh <NUM> so all, or at least a portion of, mesh <NUM> remains substantially planar as air passes through mesh <NUM>. In additional embodiments, an insert <NUM> (e.g., a thermal insert, an electrically and/or thermally insulating member, etc.) may be provided as part of door <NUM> and may electrically and/or thermally insulate clamping bars <NUM> from the remainder of door <NUM>.

Clamping bars <NUM> include a scalloped surface <NUM> designed to hold mesh <NUM> more effectively. In embodiments, surface <NUM> can have scalloped notches <NUM> (e.g., scallops, notches, recesses, etc.) along the length of clamping bar <NUM>. Scalloped notches <NUM> can improve one or more of electrical, mechanical, or thermal contact between mesh <NUM> and clamping bars <NUM> and/or bus bars <NUM>. For example, mesh <NUM> may contact a primary portion of surface <NUM> while not contacting the recessed portion of a scallop. As shown in <FIG>, the transition between the portion of mesh <NUM> sandwiched between bus bars <NUM> and clamping bars <NUM> and the unsupported portion of mesh <NUM> can occur along a line <NUM> that follows a machined scalloped profile of clamping bars <NUM>, thus increasing the length of transition line <NUM> (relative to a generally straight transition line). For example, transition line <NUM> can be more than two times longer than a straight transition line on the same clamping bar. Scallops <NUM> provide depth to the transition phenomenon that is defined by the distance from the crest of each scallop <NUM> to a front edge or surface <NUM> of each clamping bar <NUM>. The ends of the scalloped notches <NUM> can be increased to decrease the amount of contact between the edge of mesh <NUM> and clamping bars <NUM> and/or bus bars <NUM>. Deeper ended scalloped notches also reduce contact of mesh <NUM> with bus bars <NUM>, m tum minimizing heat or electronic damage that may otherwise may occur to mesh <NUM>. For example, overheating of mesh <NUM> (e.g., a stainless steel mesh) may result in deformation of mesh and/or the mesh coming apart. In some embodiments, clamping bar <NUM> may have intermittent (e.g., noncontinuous, etc.) electrical contact with mesh <NUM>.

Device <NUM> may include one or more clamping assemblies, shown in <FIG> as clamping knobs <NUM> (e.g., clamps, fasteners, etc.). Clamping knobs <NUM> can provide additional support for mesh <NUM> as it resists an airflow, including intermittent airflow that can permeate the mesh material. Clamping knobs <NUM> may be configured to secure surface <NUM> of clamping bar <NUM> and/or a surface of bus bar <NUM> into contact with mesh <NUM> disposed between clamping bars <NUM> and bus bars <NUM>. Clamping knobs <NUM> can be made of any suitable material.

In one embodiment, device <NUM> further includes one or more deflection limiters, shown in <FIG> as support disks <NUM>. Support disks <NUM> provide additional support for mesh <NUM> as the support disk may resist airflow and limit deflection of the mesh <NUM> due to pressure from the airflow <NUM> and/or from thermal expansion of the mesh <NUM> during heating, particularly near the clamping edge, where the mesh may be vulnerable to damage. Support disks <NUM> can be attached to either or both the housing <NUM> and the door <NUM> and can be of various shape, though in the illustrated embodiment they are round. In an embodiment, the support disks <NUM> are formed of an electrically non-conducting material, but may be of either a thermally conducting or thermally non-conducting material.

Referring to <FIG>, clamping bar <NUM> is shown in greater detail according to an exemplary embodiment. For example, clamping bar <NUM> includes scallops <NUM> (e.g., notches, recesses, grooves, indents, etc.). Respective scallops may have a generally curved profile extending along a surface <NUM> of clamping bar <NUM>. In other embodiments, scallops <NUM> are formed by a cylindrical machining tool (not shown) such that the tool rotates and forms the curved surface of the scallop. As such, the size, shape, and depth of the scallops can be controlled by adjusting the depth of cut and/or angle of the tool. In embodiments, one or more generally cylindrically-shaped recesses <NUM> are provided in a bottom surface of clamping bar <NUM>. Any number of recesses <NUM> may be utilized, and the recesses may take any suitable size and/or shape. In one embodiment, similarly-sized scallops <NUM> are provided adjacent to one another in a generally continuous manner along the length of clamping bar <NUM>. In other embodiments, scallops <NUM> are spaced apart along clamping bar <NUM> and/or the individual scallops may take varying shapes/sizes along the length of clamping bar <NUM>.

It should be noted that mesh testing has shown that the edges of the mesh may be more vulnerable when a crease is formed in the edge area, in which case the mesh material may start to bum at a much faster rate than creases situated in the central part of the mesh. Poor or no contact of the material, that forms the mesh, with bus bars near the edges of the mesh results in low current density in that area, with less tendency to bum if a crease is formed starting from the edge (in most instances the edge crease is formed close to bus bar). Thus, the scalloped configuration of the clamping bars may decrease the tendency of the mesh material to bum in the edge areas.

It should further be noted that there may be an additional benefit from using a square-shaped mesh. The mesh is most prone to failure along the clamping area close to the bus bars. In some instances, failure may occur gradually within approximately <NUM>,<NUM> - <NUM>,<NUM> samples because the mesh may be frequently removed from cartridge for cleaning during this time (approximately every <NUM>,<NUM> - <NUM>,<NUM> samples). A rectangular mesh restricts its installation orientation into the cartridge, while a square mesh allows placement into the cartridge on either side (e.g., multiple orientations) in such a way that the sides of the mesh with the least damage can be made to contact the bus bars while more damaged sections can directed in the path of power transfer. Thus, a square-shaped mesh may prolong the useful life of the mesh.

For purposes of this disclosure, the term "coupled" refers to the joining of two members directly or indirectly to one another. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature. Such joining may also relate to mechanical, fluid, or electrical relationship between the two components.

Claim 1:
A cartridge assembly (<NUM>) comprising:
a body portion (<NUM>), that is thermally and electrically non-conductive, defining an opening (<NUM>);
a bus bar (<NUM>) coupled to the body portion (<NUM>), the bus bar (<NUM>) being thermally and electrically conductive; and
a clamping bar (<NUM>) being thermally and electrically conductive;
wherein at least one of the bus bar (<NUM>) and the clamping bar (<NUM>) is biased toward the other of the bus bar (<NUM>) and the clamping bar (<NUM>),
characterized in that
the clamping bar (<NUM>) includes a scalloped surface (<NUM>) configured to oppose the bus bar (<NUM>), wherein the cartridge assembly (<NUM>) is configured to secure a mesh (<NUM>) between the scalloped surface (<NUM>) of the clamping bar (<NUM>) and the bus bar (<NUM>).