When a mobile material is to be applied to only one of two adjacent or contiguous surfaces, a virtually universal concern is to protect the other surface against contamination by the material. Painting or staining of the baseboard on a wall, while avoiding accidental application of the paint or stain to the floor or floor covering through inadvertent brush contact, dripping, or the like, is a prime example of the problem—but is hardly the only circumstance in which it is encountered. It is to be understood to references herein to baseboards, floors, and floor coverings are made for convenience and are non-limiting, and that the shield and method described and claimed can be used and applied for any suitable purpose, as will be evident to those skilled in the art.
When painting the baseboard in a room, a common means for protecting the adjacent floor surface employs a hand-held shielding device or tool. Such devices are typically made from aluminum or plastic, and are comprised of a panel having at least one straight edge portion that can be pressed against the baseboard with the main portion of the shield overlying the adjacent floor or floor covering. Representative or prior art disclosing shielding devices of that general character and intended for such use are the following United States published patent documents:
A major drawback inherent in paint shields of the prior art resides in their relative shortness (typically being about 12 to 18 inches long, as measured along the blade or straight-edge portion), necessitating their frequent repositioning. That procedure is not only inconvenient, awkward, and time-consuming, but moreover it requires the exercise of constant care in placement of the blade against the baseboard; and even then the flooring or floor covering is exposed to paint encroachment and contact as a result of running or dripping of paint or spring-back of the pile of an adjacent (e.g., wall-to-wall) carpet in an area from which the shield has been displaced. Furthermore, if the shield is left in place until the paint is at least semi-dry, adhesion to the shield may cause paint to pull away from the surface.
Some of the foregoing drawbacks inherent in conventional paint shields can be avoided through the use of masking or “painting” tape or, indeed, by simply laying sheets of paper or plastic, or a tarpaulin, edgewise along the baseboard. Again, however, the application of tape is time-consuming, inconvenient, not entirely effective, and impractical under some circumstances; moreover, tape wedged into a gap is likely to tear upon removal and give rise to obvious undesirable consequences. By the same token, unsecured sheets of paper, plastic, and the like are readily distorted and displaced, and are difficult to position so as to provide and maintain accurate lines of demarcation between objective and protected surfaces.
Accordingly, it is a broad object of the invention to provide a shield unit which is effective for the protection of a surface against the accidental application of a mobile material that is intentionally applied to an adjacent objective surface.
A related object of the invention is to provide a product for conveniently supplying such shield units in selectively variable lengths.
Additional related objects are to provide a protective method that utilizes such shield units, and a method for supplying them.
More specific objects of the invention are to provide a shield unit having the foregoing features and advantages, which is facile, fast, and convenient to employ, enables significant job-time reduction, is of incomplex construction and inexpensive manufacture, and is essentially suited for one-time, throw-away use.
It has now been found that certain of the foregoing and related objects of the invention are attained by the provision of a shield unit for the protection of a surface against the accidental application of a mobile material that is intentionally applied to an adjacent objective surface, the protected surface and the objective surface being separated from one another with an effective gap therebetween that extends generally longitudinally at an intersection thereof. The shield unit is long and narrow, and comprises two substantially rectangular superposed plies of a thin flexible film comprised of a synthetic resinous (i.e., plastic) material; the film will normally be at least about three and preferably at least four mils thick, and less than about 10 mils in thickness. The plies of film are connected to one another at a common rectilinear leading edge of the shield unit, and a structurally reinforcing marginal portion extends therealong. They are of substantially the same length and are joined by a multiplicity of mutually spaced transverse bond, or securement, lines that extend across the shield unit to define, between the plies of film, a plurality of pockets that are open adjacent a trailing edge of the shield unit for the receipt of a tool (or a blade-like member thereof) for aiding insertion of the leading edge into such an effective gap.
In preferred embodiments the shield unit is at least 30 inches long and four inches wide. A top ply of the film comprising the shield unit will preferably be substantially narrower than a bottom ply thereof so as to space, or offset, a trailing edge of the top ply away from a trailing edge of the bottom ply and thereby facilitate entry of a tool into each of the plurality of pockets. The multiplicity of intermediate transverse bond lines will advantageously be mutually spaced about two to eight, and preferably three to six, inches from one another, and two of the transverse bond lines will generally be disposed at opposite ends of the unit. Separate lengths of film constituting the plies of the shield unit may be bonded to one another, or a single length of film may be folded, creased, and bonded, in either case providing the leading edge and, at least in part, the structurally reinforcing marginal portion, which portion may be augmented by means such as a row of transversely oriented corrugations or an attached, supplemental layer of film.
The shield unit will beneficially include at least one continuous or discontinuous adhesive element disposed on a lower face of the bottom ply of film, along and adjacent the trailing edge of the shield unit, for securement to the protected surface. Similarly, at least one adhesive element may desirably be disposed on an upper face of the bottom ply of film, along and adjacent the trailing edge, to enable securement of an auxiliary web of material to the shield unit; such an auxiliary web may be extended beyond the trailing edge of the shield unit to thereby enlarge the area of protection provided.
Other object of the invention are attained by the provision of a shield strip for providing the shield units hereinabove and hereinafter described. Such a shield strip is divisible along its length to provide a plurality (i.e., two or more) of the shield units.
Additional objects of the invention are attained by the provision of a method for the application of a mobile material to an objective surface while protecting an adjacent surface against the accidental application of the mobile material thereto, utilizing the shield unit hereinabove and hereinafter described, the surfaces being separated from one another by an effective gap that extends generally longitudinally at an intersection thereof. The method includes the following steps (in addition to providing the described shield unit): providing a tool having a blade-like member; positioning the shield unit along the effective gap between the surfaces, with the leading edge of the shield unit aligned for entry into the gap; inserting at least the blade-like member of the tool into at least one of the pockets of the shield unit; applying force to the tool so as to cause the blade-like member thereof to push effectively against the marginal portion of the shield unit (from within the pocket) and thereby assist in advancing the leading edge of the shield unit into the effective gap between the objective and protected surfaces; repositioning a bottom ply of the plastic film, if necessary (normally after withdrawing the tool), to cause it to lie substantially flat upon the protected surface; and applying a mobile material to the objective surface.
Generally, in carrying out the foregoing method the objective surface and the protected surface will be substantially perpendicular to one another; and more particularly the objective surface will often be that of a baseboard, the protected surface will be that of a floor or floor covering, and the applied mobile material will typically be paint, varnish, shellac, or stain. In those instances in which the shield unit additionally includes an adhesive element disposed on the upper face of the bottom ply of the film, as described, the method may include further steps of securing an auxiliary web of material to the adhesive element and extending the auxiliary web beyond the trailing edge of the shield unit and over the protected surface.
Objects of the invention are also attained by the provision of a method for the application of a mobile material to an objective surface, while protecting an adjacent surface, in which a shield strip is provided. In addition to the other steps described, such a method will include a step of cutting or otherwise severing the shield strip transversely, at least at one location along its length, so as to provide a plurality of shield units, each having at least one pocket therein, for insertion into the gap between the surfaces involved.
Turning initially to
A bond line 20 extends partially across the shield unit 10 at its opposite ends and provides narrow areas of securement traversing the width of the top ply 14, and three intermediate bond lines 22 extend across the width of the top ply between the opposite ends. The bond lines 20, 22 affix the top ply 14 to the bottom ply 12 at their respective locations so as to define (in the embodiment illustrated) four adjacent pockets 24 along the length of the shield unit. Each of the pockets 24 has an open end 26 at the trailing edge 28 of the top ply 14, which is offset from the trailing edge 30 of the bottom ply 12. This arrangement facilitates entry of the relatively flat, thin, and strait-edged blade of an insertion tool T (e.g., a putty knife) into the pockets 24, with the tool T being used to aid insertion of the leading edge 16 of the shield unit 10 and being moved from pocket-to-pocket 24, as necessary or advantageous. An adhesive strip 32 extends along the underside of the bottom ply 12, and would normally be covered by a removable release element (not shown) of essentially non-adherent material, which would be peeled away in the course of use of the shield unit.
As seen in
Turning now to
In
While the plies of the shield unit (and consequently of the shield strip) may be fabricated from a single plastic material, it will be appreciated that they may comprise two or more polymers, and may include (albeit perhaps with excessively reduced flexibility) foil and/or paper lamina. Thermoplastics, such as the polyolefins (e.g., high density polyethylene or polypropylene), will generally be preferred from standpoints of facilitating bonding of the plies to one another under heat and pressure, toughness (even in relatively thin gauges, and especially if the film is biaxially oriented), ready availability, and cost. Moreover, such plastics are typically flexible, and usually exhibit relatively low coefficients of friction, both of which properties are desirable for facilitating insertion of the leading edge of a shield unit into a gap between adjacent surfaces, even when the path to be followed is of compound cross-section. Thus, while the leading edge of the shield unit must be sufficiently rigid to enable ready introduction an insertion without buckling under the forces applied, still it must be able to follow a path within a floor/baseboard construction that may include one or two angle bends. Flexibility of the plastic also promotes a lay-flat condition of the bottom ply on top of the protected surface.
The plies of the shield unit may alternatively be fabricated from thermosetting resins, such as polyesters and silicones, albeit bond lines could not then be produced by thermal fusion. It will be appreciated that securement of the plies to one another may, in any event, be effected by any suitable means including, for example, applications of adhesives or solvents, ultrasonic welding, and mechanical crimping (all such means being encompassed by the term “bonding,” as used herein).
Although the plies of flexible film comprising the shield unit will normally be at least about four mils thick, in some instances elements as thin as three mils may be utilized. This will depend essentially upon the toughness and tensile strength of the material and its consequential ability to withstand insertion and withdrawal forces without rupturing or tearing. Plies in excess of 10 mils will usually be too thick.
As a matter of practicality and economy, each shield unit will desirably be at least about 30 inches in length and three to eight, or preferably four to five, inches in width, with an offset of about one-quarter inch to one-inch of the trailing edge of the top ply from the trailing edge of the bottom ply, albeit in some cases introduction of at least the blade of an insertion-assisting tool might be achieved in the absence of any offset.
When provided in the form of a “continuous” strip, the shield will normally be at least eight feet long (corresponding to the full width of a drywall panel), although certainly longer lengths (e.g., 20 feet or more) may be more practical and desirable, depending largely upon the form in which the shield strip is provided.
In most instances, transverse bond lines across a shield unit will be mutually separated by not less than about two, and preferably not less than three, inches, or more than about four, and preferably not more than six, inches. Here again, however, these dimensions may vary, and will depend in part upon the width of the flat forward edge of the tool that is to be used for insertion, and the desired stabilization effect of the bond lines; i.e., if the lines are too far apart the shield unit will tend to distort, whereas if they are too close together the width of the tool blade used would be limited and insertions into an excessive number of pockets might be required. The bond lines will normally be oriented perpendicular to the leading edge of the shield unit, but here again variation is feasible.
As indicated above, the transverse bond lines may provide convenient sites for severance of the shield units from one another, and indeed it may be desirable to provide perforations along a bond line so as to facilitate manual separation of the shield units from one another. As is also described above, continuous-length shield strips will conveniently be provided in roll form or as a fan-folded stack. In such instances, the strip may be contained in a package that facilitates dispensing and that has means for severing the units from one another, such as a cutting bar, serrated edge, etc. Individual shield units may also be packaged so as to provide a range of lengths (e.g., three, eight, 12 and 16 feet), among which selection may be made to obtain a unit or section of optimal length for a given application.
In addition to painting, staining, and the like, the shields of the present invention may, for example, be used for cleaning, recaulking, sanding, etc., among other applications that will be evident to those skilled in the art. Similarly, treatment of trim work, moldings, doorjams, window frames, and the like may employ the shields hereof, and while protection of flooring has been emphasized it will be appreciated that the shields may be employed to protect wall surfaces above baseboards as well. Many variations may occur to those skilled in the art, based upon the present description, without departure from the appended claims
Thus, it can be seen that the present invention provides a novel shield unit which is effective for the protection of a surface against the accidental application of a mobile material that is intentionally applied to an adjacent objective surface, and which units may conveniently supplied in selectively variable lengths. The shield units are easily and conveniently employed, are of incomplex construction and inexpensive manufacture, and are essentially suited for one-time, throwaway use. The invention also provides a protective method that utilizes such shield units, and a method for supplying them.
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