Abstract:
A cleaning swab is for wet or dry use. The swab includes an elongated handle defining a longitudinal axis. The handle has a cleaning head end and a grasping end. The swab includes a multi layer cleaning head having a core, a mid-layer and an outer layer. The core and the mid-layer are absorbent. The outer layer is formed from a cleaning textile. The outer layer is sealed to itself and to the handle to isolate the core and mid-layer.

Description:
BACKGROUND OF THE INVENTION 
   The present invention is directed to a swab for cleaning. More particularly, the present invention pertains to a multi-layer swab having a sealed outer layer or cover. 
   Swabs are used in all manners of cleaning. For example, everyone will recognize common cotton tipped swabs that are used for person hygiene and care. Because of the compact and effective nature of these swabs, they have been adopted for use in numerous areas of technology and manufacture. One such area is the manufacture of advanced optical components for use in aerospace and navigation systems. 
   During manufacture and use of optical components it is not unusual for pieces of manufacturing debris, such as dust and fibers or other particulate debris to be left on surface of the components. It is also not unusual for light oils, such as fingerprint and other natural skin oils to be found on many of these parts. The debris and oils can significantly degrade, distort or prevent the proper and precise transmission of images. 
   Numerous types of cleaning implements have been used, with some degrees of success, to clean these particularly sensitive areas. It has, however, been observed that cleaning implements formed from non-particulate removing materials may not be acceptable for this use. Specifically, it has been found that particulates that are not removed can become lodged in and around these components, thus adversely effecting the quality of the images. 
   Often, liquids are used to assist in the cleaning process. For example, water or other light solvents maybe applied to the swab to assist in removing contaminants such as oils, particulates and the like. 
   Other cleaning swabs have also been used with varying degrees of success. For example, one known swab includes a polyurethane foam over a cotton core. However, it has been found that polyurethane is not sufficiently soft (for contact with sensitive components and surfaces), and is not sufficiently hydrophilic (to absorb water or other solvents) to facilitate the cleaning process. 
   Accordingly, there exists a need for a swab-type cleaning device that can be used for cleaning sensitive components and surfaces. Desirably, such a device leaves little to no residue from the device within the component or on the surface. More desirably, such a device can be used wet or dry; that is, it can be used with or without a solvent (such as water) to facilitate cleaning. Most desirably, such a cleaning device is structurally stable when wet, serves well to distribute any liquid throughout the device and is resistant to cutting. 
   BRIEF SUMMARY OF THE INVENTION 
   A cleaning swab is for wet or dry use. The swab includes an elongated handle and a multi layer cleaning head. The swab can be used for cleaning sensitive components and surfaces such as those found in advanced optical equipment. The swab leaves little to no residue (from the swab) within the component or on the surface. Such a swab is structurally stable when wet and serves well to distribute any liquid throughout the swab cleaning head. 
   The multi layer cleaning head has a core, a mid-layer and an outer layer. The core and the mid-layer are formed from absorbent materials. In a present embodiment, the core is formed from cotton and the mid-layer is formed from a foam, such as a polyurethane foam. 
   The outer layer is formed from a cleaning textile, such as polyvinyl acetate (PVA) or a micro denier cleaning fabric. Preferably, the outer layer is sealed to itself and to the handle to isolate the core and mid-layer to, for example, prevent the egress of particulate and fibers from the core and mid-layer. The outer layer can be sealed by, for example, heat sealing to itself and to the handle. 
   The handle can be formed from wood or a plastic material, preferably one that is static dissipative. 
   These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein: 
       FIG. 1  illustrates a multi-layer sealed swab embodying the principles of the present invention; and 
       FIG. 2  is an enlarged, cross-sectional view of the swab head. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. 
   It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein. 
   Referring to the figures and in particular to  FIG. 1  there is shown a multi-layer sealed swab  10  in accordance with the principles of the present invention. The swab  10  includes a handle  12  and a cleaning head  14 . The cleaning head  14  is formed in a multi-layered construction as best seen in  FIG. 2 . The present swab  10  can be used for cleaning sensitive components and surfaces such as those used in fiber optics and other telecommunications equipment. A swab  10  in accordance with the present invention leaves little to no residue (e.g., fibers) from the device within the component or on the surface, and can be used wet or dry (i.e., with or without a solvent) to facilitate cleaning. The swab  10  has been found to be structurally stable when wet and serves well to distribute any liquid (e.g., solvent) throughout the cleaning head  14  for cleaning. 
   In a present embodiment, the handle  12  is formed from a wood or polymeric material, such as polypropylene or the like formed in an injection or extrusion molding process. The handle  12  can also be formed as a plastic alloy or a filled plastic to provide enhanced static dissipative properties. The handle has first and second or cleaning and grasping ends,  16 ,  18 , respectively. 
   The cleaning head  14  is formed in a multi layer construction. In one embodiment, the head  14  includes a core  20  formed from a bud of cotton. The core  20  is covered with a middle layer  22  (also referred to as a mid-layer) of hydrophilic material, such as an open-cell polyurethane foam. In a present embodiment, the mid-layer  22  is a 100 ppi open-cell polyurethane foam. 
   The hydrophilic mid-layer  22  is then covered with an outer layer  24  of a cut resistant material. Preferably, the outer layer  24  is a cleaning fabric or textile. One outer layer  24  material is a layer of polyvinyl acetate (PVA) foam. Alternately, the outer layer  24  is formed from a polyester, micro denier or other suitable cleaning textile or fabric. 
   The outer layer  24  is sealed or seamed to itself (as indicated at  26 ) so as to fully enclose the middle layer  22  and core  20 . Preferably, the outer layer  24  is also sealed or welded to the handle  12  (as indicated at  28 ) to essentially isolate the middle layer  22  and core  20 . Sealing the outer layer  24  onto itself (as at seam  26 ), as well as at the handle  12 , serves to fully isolate the mid-layer  22  and core  20  to prevent the egress of fibers or other particulate matter from the mid-layer  22  and core  20 . 
   In a present swab  10 , the mid-layer  22  has a thickness t 22  of about 5.0 mm and the outer layer  24  has a thickness t 24  of about 1.0 mm. The thicknesses of the various layers can vary depending upon the specific desired application or use for the swab  10 . 
   In an alternate construction (not shown), the core and middle layer can be combined into a single core portion formed from, for example, polyurethane foam. The polyurethane foam can be bonded directly to the handle by welding or ultrasonic techniques to melt the foam and handle together. 
   It is anticipated that the swab head or cleaning head  14  will be formed in various sizes and shapes for a variety of specific cleaning tasks. The cleaning head  14  can be formed in an oval or ovate shape, it can be formed in a rectangular shape, or any other shape as needed for a particular application. 
   It has been found that the present novel swab  10  construction provides a number of advantages over known swabs. First, the outer layer  24 , being sealed or seamed (as by, for example, heat) provides a neat and soft sealed seam  26 . This is in contrast to known PVA swabs which are wrapped over cotton or are simply glued to handles. 
   In addition, the polyurethane foam mid-layer  22  beneath the outer layer  24  provides a number of enhanced cleaning features. First, the mid-layer  22  provides structural stability to the outer layer  24 . Those skilled in the art will recognize that when the outer layer  24  (e.g., PVA) becomes wet with water, it can absorb an enormous times its weight in water. As such the outer layer  24  can become structurally unstable, sagging and possibly tearing under its own weight (with the absorbed water). 
   It has been found that the polyurethane mid-layer  22  beneath the outer layer  24  distributes the weight of the water more evenly and supports the weight more effectively. As such, the present swab  10  has considerably more structural integrity than known swabs. 
   The polyurethane foam mid-layer  22  further serves to store additional solvent (e.g., water) to maintain the outer layer  24  wet. That is, the polyurethane foam mid-layer  22  essentially serves as a reservoir to store water for use and absorption by the outer layer  24  for cleaning. 
   Moreover the polyurethane foam mid-layer  22  protects the cotton core  20  when the swab  10  is used around sharp edges. It has been found that the present construction, when used to clean surface mirrors and advanced optics that may have sharp edges, prevents cutting through the outer layer  24  and possible subsequent release of fibers from the cotton core  20 . As such, no fibers are released by the present swab  10  that could otherwise contaminate the surfaces and components of sensitive fiber optic equipment. 
   It has also been found that the present swab  10  is sufficiently flexible to conform to the shape of the surfaces being cleaned, while at the same time it is sufficiently resilient to retain its shape. This combination or balance of resiliency and flexibility provides enhanced cleaning characteristics when compared to known swabs. 
   Importantly, it has also been found that when used with a cleaning textile outer layer  24  (such as PVA or micro denier), excellent cleaning and contamination removal characteristics have been shown. Micro denier and PVA have been shown to exhibit superior cleaning abilities, particularly with respect to the removal of contaminants, when compared to other materials, such as foam. In combination with the foam, however, it has been found that the outer layer  24  cleaning ability is enhanced by the ability of the mid-layer  22  and core  20  to provide a sufficient reserve or reservoir of cleaning solution. It has also been found that the foam mid-layer  22  provides a sufficient cushion to moderate the pressure applied during cleaning, as well as (as set forth above) conformance to the shape of the surface being cleaned. 
   Advantageously, the present swab  10 , unlike known polyurethane foam over cotton core swabs, provides a soft, hydrophilic cleaning implement. Moreover, the unique combination of the cleaning material outer layer  24  foam mid-layer  22  offers a balance between softness (for conformance to the surface of the article being cleaned) and stiffness (to assure good contact and complete cleaning), while at the same time providing absorption for retaining solvents such as water to facilitate the cleaning process. 
   All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure. 
   In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular. 
   From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.