Patent Abstract:
A brush for applying a viscous coating to surfaces such as a driveway, has a composition and conformation promoting an even application of the coating. The brush has bristles of a given, number, density/spatial distribution, free length, thickness and elastic modulus that in combination provide a controlled leakage of viscous coating past the brush when the handle thereof is held at a given angle and subjected to a given downforce to facilitate applying the coating.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/046,594, entitled Brush and Methods of Use, filed Sep. 5, 2014, which is incorporated by reference herein in its entirety. 
     
    
     FIELD 
       [0002]    The present invention relates to brushes, and more particularly, to brushes used as applicators for coatings applied to surfaces. 
       BACKGROUND 
       [0003]    Various brushes and applicators are known for use in applying coatings, such as paint, glues, topcoats, etc. Notwithstanding, improved and/or alternative brush designs and methods for using them remain desirable for various applications. 
       SUMMARY 
       [0004]    The disclosed subject matter relates to a brush for applying viscous coatings. In one approach, the coating may be in the range of 2,500 CPS to 15,000 CPS and the brush has a brush head with a plurality of bristles having a modulus of elasticity in the range of 2-4 GPa, a diameter in the range of 0.25 mm to 1.0 mm and a free length of 1.5-2.5 inches. The overall brush thickness may be in the range of 0.75 inch to 1.0 inch. The brush may have a total bristle count of 2,500 to 3,500 and a width to thickness to height ratio in the range of 20:1.5:1.5 to 30:0.75:2.5. 
         [0005]    In accordance with one aspect of the disclosure, The brush has a handle attached s to the brush head at an angle such that when the handle is held at an angle in the range of 10 to 40 degrees relative to the surface to be coated, the surface of the brush head defined by the terminal ends of the plurality of bristles is substantially flat on the surface +/−15 degrees. 
         [0006]    In accordance with one aspect of the disclosure, an inner angle between the handle and the brush is about 120 degrees. 
         [0007]    In accordance with one aspect of the disclosure, the brush head has a root portion with upper and lower portions, the lower portion attached to the bristles, the upper portion disposed at an inside angle of about 150 degrees relative to the lower portion, the handle connecting to and forming an angle of approximately 90 degrees relative to the upper portion. 
         [0008]    In accordance with one aspect of the disclosure, the bristles are bent around a wire and crimped in a frame, the frame being attached to the root portion. 
         [0009]    In accordance with one aspect of the disclosure, the bristles are nylon. 
         [0010]    In accordance with one aspect of the disclosure, a support web extends between the handle and the brush head. 
         [0011]    In accordance with one aspect of the disclosure, the inside angle between the bristles and the handle is about 120 degrees. 
         [0012]    In accordance with one aspect of the disclosure, the brush head is attached to the handle by a tab and mating slot. 
         [0013]    In accordance with one aspect of the disclosure, the brush head is attached to the handle by a mating sleeve and cylinder. 
         [0014]    In accordance with one aspect of the disclosure, the brush head has a clamp for removably retaining a crimped metal frame in which the bristles are retained, the clamp removably attaching to the handle. 
         [0015]    In accordance with one aspect of the disclosure, the brush head is attached to the handle by a mating threaded end of the handle received in a threaded aperture in the brush head. 
         [0016]    In accordance with one aspect of the disclosure, the brush is capable of applying coatings in the viscosity range of 2,500 CPS to 15,000 CPS. 
         [0017]    In accordance with one aspect of the disclosure, the film of the coating applied when the brush has an applied downforce of about 2 to 10 lbs. is between 25 to 50 mils. 
         [0018]    In accordance with one aspect of the disclosure, the brush is capable of applying an even coating to a surface which has a roughness of about ⅛ inch without skips. 
         [0019]    In accordance with one aspect of the disclosure, the bottom surface of the brush head has a surface area of about 18 inches 2 . 
         [0020]    In accordance with one aspect of the disclosure, the bottom surface of the brush is substantially parallel to the surface to which the coating is applied when the handle is at 30 degrees relative to the surface to which the coating is applied. 
         [0021]    In accordance with one aspect of the disclosure, the brush is capable of applying the viscous coating when pushed or pulled. 
         [0022]    In accordance with one aspect of the disclosure, the root portion has an upper channel and a lower channel, the lower channel receiving the frame and the upper channel having a fastener that couples to a bracket on the handle. 
         [0023]    In accordance with one aspect of the disclosure, further including a frame fastener extending into the lower channel retaining the frame portion within the lower channel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    For a more complete understanding of the present disclosure, reference is made to the following detailed description of exemplary embodiments considered in conjunction with the accompanying drawings. 
           [0025]      FIG. 1  is side view of a brush in accordance with an embodiment of the present disclosure in three alternative orientations relative to a surface. 
           [0026]      FIG. 2  is an enlarged view of the brush of  FIG. 1  showing the angular orientations of a face of the brush relative to the surface in the three orientations of  FIG. 1 . 
           [0027]      FIG. 3  is an exploded view of a brush in accordance with another embodiment of the present disclosure. 
           [0028]      FIG. 4  is side view of the brush of  FIG. 3 . 
           [0029]      FIG. 5  is a cross-sectional view of the brush of  FIG. 4  taken along line  5 - 5  and looking in the direction of the arrows. 
           [0030]      FIG. 6  is a perspective view of a brush in accordance with another embodiment of the present disclosure. 
           [0031]      FIG. 7  is a top view of the brush of  FIG. 6 . 
           [0032]      FIG. 8  is an exploded view of a brush in accordance with another embodiment of the present disclosure. 
           [0033]      FIG. 9  is an exploded view of a brush in accordance with another embodiment of the present disclosure. 
           [0034]      FIG. 10  is an exploded view of a brush in accordance with another embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0035]      FIGS. 1 and 2  shows a brush  10  with an elongated handle  12  made from wood, metal or plastic. A rubber/foam grip  12 G may be disposed on the handle  12  to soften the gripping surface for the hands of the user and/or to improve the grip that the user has on the handle  12 . The handle  12  is attached to a brush head  14  that features a bristle portion  16  having a plurality of bristles  16 B held within a bristle holder  18 . The brush  10  may be used to apply a coating  20 , such as driveway sealer or coating to a surface  22 , such as an asphalt or blacktop driveway. In applying the coating  20 , the brush may be held with the handle  12  at an angle A of, e.g., 10 to 40 degrees relative to the surface  22  and pushed by the user, forming a wave  20 W of coating  20  at the front of the brush  10  in the direction  24  that the brush  10  is pushed. The bottom surface  26  formed by the bristles  16  is maintained approximately parallel to surface  22  (position P 2 ), varying from angle B of about 15 degrees with the brush tilted back (position P 1 ) to angle C of 15 degrees with the brush tilted forward (position P 3 ), as the brush  10  is pushed over surface  22  to apply the coating  20 . When pushed along a surface  22  with a component of force D (down pressure) directed perpendicular to the surface  22  of about 2 to 10 pounds, the bristles  16 B are of a number and strength such that the bristles  16  curve only slightly at the tip. This type and level of bristle  16 B response to the pushing of the brush  10  interacts favorably when the brush  10  is used to apply a viscous coating  20  to a surface  22 , such as a driveway, which is anticipated to have a degree of surface roughness attributable to coarse aggregate, e.g., crushed  2   0  stone. In addition to a pushing motion in direction  24 , the brush may be pulled in the opposite direction, to spread the coating on the surface. When being pushed or pulled, the brush  10  engages the surface  22  closely enough to form a partial “seal” with the surface  22 , allowing a layer of coating  20  of an appropriate thickness to escape past the interface I between the brush  10  and the surface  22  and remain on the surface  22  after the brush  10  has passed over it. The “seal” formed at the interface I has a controlled “leakage,” which generates the coating layer  20  of appropriate thickness. The remainder of the coating  20  which does not pass through interface I, is pushed as a wave  20 W in front of the brush  10 . In traversing the rough surface  22 , the bristles  16 B have sufficient flexibility to accommodate the roughness of the surface  20  by localized bending without breaking the overall “seal” of the brush  10  to the surface  20 . 
         [0036]      FIGS. 3 and 4  show a brush  110  in accordance with an embodiment of the present disclosure. The brush  110  has a handle  112  with a threaded end  112 T. The brush head  114  has a bristle portion  116  having dimensions approximating twenty-four (24) inches in width W, three-quarters (¾) inch in thickness T at the bottom surface  126 , and two (2) inches in free length/height H, resulting in a dimensional ratio of width to thickness to height (W:T:H) of 24:3/4:2 and bottom surface  126  having a surface area of 24*0.75=18 inches 2 . The bristle holder  118  has a root portion  118 R which is attached to a frame portion  118 F. The frame portion  118 F may be formed from sheet metal, e.g., steel, that is formed into a channel shape into which the bristles  116 B may be inserted and then the frame portion  118 F crimped down to retain the bristles  116 B. The root portion  118 R has a recess  118 RR to receive the frame portion  118 F therein, where it may be spot welded or otherwise attached, e.g., by sheet metal screws or an adhesive such as epoxy, to the root portion  118 R. The root portion  118 R may be provided with an aperture  118 RA to receive a handle  112  and both the handle  112  and the aperture  118 RA may be threaded to be matingly and threadedly attached. The root portion  118 R may have an upper portion  118 RU that is angularly offset from a lower portion  118 RL, i.e. by inside angle B of about 150 degrees corresponding to outside angle C of about 30 degrees. The handle  112  may insert into the upper portion  118 RU at approximately 90 degrees, resulting in an angle D between the lower portion  118 RL and the handle  112  of about 120 degrees. In this configuration, the bottom surface  126  of the bristle portion  116  will be substantially parallel to the surface  122  when the handle  112  is held at an angle E of about 30 degrees relative to the surface  122 . 
         [0037]    The individual bristles  116 B may be made from a resilient material, such as nylon, which is compatible for use with the compounds and coatings it is intended to apply, e.g., asphaltic compounds and coatings, such that the solvents used to maintain such compositions in a flowable state would not dissolve the bristles  116 B. The same considerations apply to the bristle holder  118 , in that it can not be compromised, e.g., softened by the coating that the brush  110  is intended to apply. The bristles  116 B have a cylindrical cross-sectional shape with a diameter in the range of 0.25 mm to 1.0 mm and an overall length of about 2.0 to 3.0 inches, e.g., 2.5 inches (63.5 mm), 2.0 inches (50.8 mm) of which is free length and the remainder is captured in the frame portion  118 F. As shown in  FIG. 5 , the bristles  116 B may be retained in the frame portion  118 F by a core  118 C, e.g., a wire, each bristle  116 B being bent into a U-shape over the core  118 C. This form of construction ensures that the bristles  116 B are securely retained in the bristle holder  118  along the entire width of the bristle portion  116 . If the individual bristles  116 B are made from nylon (typically having an elastic modulus E in the range of 2-4 GPa), the stiffness of each bristle  116 B may be calculated, e.g., k=(A (cross-sectional area)*E (elastic modulus))/L (length). If the total number of bristles  116 B (counting both sides of a U-shaped bristle bent over a core  118 C) is in the range 2500 to 3500 then the resultant cumulative stiffness k C =k*total number of bristles. If the surface area of the bottom surface  126  is in the range of 15 inches 2  to 25 inches 2 , then the stiffness per inch 2  may also be calculated. In accordance with an embodiment of the present disclosure, a brush  110  having a dimensional ratio of width to thickness to height (W:T:H) in the range of 20:1.5:2 to 30:0.75:2.5 made with nylon bristles having the dimensions and density described above will exhibit suitable bristle deformation and suitable leakage past the brush  110  when applying coatings having a viscosity in the range of 2500 CPS to 15000 CPS. A down force in a range of 2 to 10 lbs. may be applied on a handle  112  disposed at an angle in the range of 10 to 40 degrees relative to the surface  122  to which the coating  120  is applied. This results in a leakage past the brush  110  that effectively applies the coating  120  to the surface  122 . 
         [0038]      FIG. 6  shows a brush  210  where the brush head  214  is supported by a sleeve  230  disposed about the handle  212  and braces  232  that attach to and extend from the sleeve  230  to the frame portion  218 F. 
         [0039]      FIG. 7  shows a brush  310  with a brush head  314  having a support web  332  that may be formed from stamped metal or molded plastic. The web intermediates between and attaches to the root portion  318 R into which a handle  312  is received and to the frame portion  318 F of the brush head  314 . 
         [0040]      FIG. 8  shows a brush  410  with a brush head  414  to which is attached a root portion  418 R. The root portion  418 R has an attachment cylinder  418 C that extends up from the root portion  418 R at an angle and is received in a coupling sleeve  412 S that is attached to the handle  412 . A rivet or screw  412 P may be used to retain the sleeve  412 S on the cylinder  418 C. The root portion  418 R may be spot welded, screwed or otherwise attached to frame portion  418 F. 
         [0041]      FIG. 9  shows a brush  510  with a brush head  514 . The bristle holder  518  has a root portion  518 R. The root portion  518 R has an attachment tab  518 T that extends up from the root portion  518 R at an angle and is received in a slotted coupling  5125  that is attached to the handle  512 . One or more rivets or bolts/nuts  512 P may be used to retain the coupling  5125  on the tab  518 T. The root portion  518 R may be spot welded, screwed or otherwise attached to frame portion  518 F. 
         [0042]      FIG. 10  shows a brush  610  with a brush head  614  and a bristle holder  618  with a root portion  618 R. The root portion  618 R has a lower channel  618 LC that can receive the frame portion  618 F. One or more bolts  618 B can be tightened down to grip the frame portion  618 F and retain it the lower channel  618 LC. An attachment bolt  618 AB that extends up from the root portion  618 R and is received in a coupling plate  612 P that extends from a coupling bracket  612 B which attaches to the handle  612 . The bracket  612 B may be glued, threadedly coupled, bolted or riveted to the handle  612 . A wing nut  612 W may be used to retain the plate  612 P to the root portion  618 R via attachment bolt  618 AB. The plate  612 P may be shaped to mate with the surface of the upper channel  618 UC. The brush  610  allows the bristle portion  616  to be replaced without disposing of the remainder of the brush head  614 . 
       EXAMPLE 1 
       [0043]    A driveway sealer made from asphalt typically has a viscosity in the range of 2,500 to 15,000 CPS. The desired coating thickness or film to be applied with a driveway sealer of this type is 50 mils in total thickness. The total thickness of driveway sealer may be applied in 2 separate passes or coats which are allowed to dry between coats. In this example, the desired thickness for each coat of sealer is therefore 25 mils. Preferably, the coating applied will not exceed 50 mils in thickness for each coat and each coat will be substantially even. A brush  10  having attributes in accordance with the present disclosure was used to apply a coating of driveway sealer obtained from Gardner-Gibson and known by the brand Ultramaxx 1000. The bristle portion  16 B had the following dimensions: Width: 24 inches, Height (bristle free length): 2.5 inches, Thickness: 0.75 inches, having 130 bristles/inch, i.e., 3120 bristles full width of the 24 inch wide bristle portion  16 . The sealer had a measured viscosity of 8000 CPS at 77° F. The sealer was applied to a flat blacktop driveway having a surface roughness of about ⅛″ irregular. The temperature of the driveway surface at the time of application was 90° F. The handle  12  of the brush  10  was 5 feet long and held at an angle of about 30 degrees. The brush head  14  was weighted with a weight of ½ lb to generate a constant down force. A puddle of sealer having a volume of about 2 gallons was poured in front of the brush  10  and the brush  10  was advanced a distance of 20 feet in about 1 minute. Upon inspection, the coating  20  was applied with no skips or bare spaces in the coating layer. The area coated exhibited comprehensive coating of the rough surface, including low spots (valleys between aggregate) and high spots (at the points of the aggregate that extend upwardly). The coating of sealer was allowed to dry and the thickness of the coating was measured at various points on the coated surface and was found to be about 21 mils thick, varying by no more than about 5% over the coated surface. 
         [0044]    A brush  10 ,  110 ,  210 , etc. in accordance with the present disclosure and used in accordance with the present disclosure functions like a squeegee when applying a viscous coating material. The bristles  16 B are firmly held and closely arranged together preventing passage of the coating  20  through the upper part of the bristle portion  16 , proximate the bristle holder  18 . The bristles  16 B do not bend excessively under the down force D typically required to advance the brush  10  over a surface  22  while applying viscous coating  20  on the surface  22 . The action of the brush  10  in pushing the coating  20  allows the coating  20  to penetrate nooks and crevasses in a rough surface, such as a blacktop driveway and maintains even coating over the area of application. When used for spreading a viscous coating  20 , the bristle portion  16  maintains its shape, in that the edges do not curl up. 
         [0045]    In applying high viscosity coatings ranging from 2500 CPS to 15000 CPS, the brush  10  is able to adapt to the changing down force D required to spread the coating  20  without distortion of the bristles  16 B. The rubber/foam sleeve(s)  14  on the handle  12  allows the handle  12  to be gripped firmly without slipping and increases control of the user over the brush  10 , as well as reducing fatigue for the user. The brush  10  allows the user to redirect the brushing direction  24  by any angle, e.g., 90 or 180 degrees and still push the coating  20  in a continuous layer without gaps in coverage. 
         [0046]    It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the present application. All such variations and modifications are intended to be included within the scope of the present application and claims.

Technology Classification (CPC): 0