EP3764865B1

EP3764865B1 - Floor bristle brush assembly

Info

Publication number: EP3764865B1
Application number: EP19768606.6A
Authority: EP
Inventors: James L. ERICKSON; Samad JAVID; Lijun Zu
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2018-03-13
Filing date: 2019-03-08
Publication date: 2024-08-07
Anticipated expiration: 2039-03-08
Also published as: WO2019175730A1; MX2020009383A; US20210000248A1; CN111818835A; EP3764865A4; AU2019234025A1; AU2019234025B2; EP3764865A1

Description

Background

Concrete, terrazzo and other hard surfaces are often used in both residential and commercial flooring applications because they provide a robust and economical flooring solution. In some instances, such a floor may be left unfinished, partially finished, or completely finished, depending on the desired level of gloss. In some commercial settings, such as bulk retailers or home improvement stores where flooring experiences high volumes of heavy foot and machine traffic, the store prefers not to apply floor finishes or sealers due to the expense and time required for continued upkeep of the finishes or sealers.
Currently, non-woven abrasive floor pads or rigid abrasive systems (such as the Diamabrush sold by Diamabrush LLC of Madison Heights, Michigan) are used for floor finishing or cleaning. Nonwoven floor pads can be an expensive and inefficient solution because they are not as durable when used on a bare concrete surface. Rigid abrasive systems may last longer, but have a tendency to yield inconsistent or uneven results in the floor surface. Rigid abrasive systems also often miss low spots due to the rigidity of the construction. Additionally, when a particular component of a rigid abrasive system wears out, the component is typically not replaceable, leading to premature disposal of the entire system.
Several patents mention the problem of effectively cleaning flooring. One such patent is United States Patent 5,679,067 "Molded Abrasive Brush" to Johnson et al. This patent describes an abrasive brush having a plurality of bristles unitary with the backing. These brushes can be mounted to a backing, which is in turn mounted to a driver if used for a floor cleaning machine.
United States Patent 8,206,201 "Working System Using Brush Tool" to Fioratti _discusses a brush tool that can have bristles of different sizes and can be mounted to a tool head of a tool machine.
Opportunity exists for improved systems for cleaning, resurfacing and finishing floors.
US 5 679 067 A relates to a molded abrasive brush having a backing with a plurality of bristles extending therefrom. The backing and bristles are preferably integrally molded. The brush is molded from a moldable polymer such a thermoset polymer, thermoplastic polymer, or thermoplastic elastomer. The moldable polymer includes a plurality of organic or inorganic abrasive particles interspersed throughout at least the bristles and can be interspersed throughout the brush. The moldable brush can include an attaching means molded integrally with the backing.
CA 2 547 300 A1 relates to an abrasive brush having a plurality of bristles unitarily moulded with a base, and mote particularly to an abrasive brush made by injection moulding a mixture of polymer and abusive particles. The brush can include organic or inorganic abrasive particles. The document also relates to abrasive filaments comprising a thermoplastic matrix having plastic abrasive particles dispersed therein. The brush can be constructed as a driven brush body.
KR 2012 0124701 A relates to a grinding pad including a basic material and a brush unit. The brush unit is attached to the basic material. The brush unit includes a base and a plurality of bristles. The plurality of the bristles is projected from one surface of the base. The plurality of the bristles combines with the base.
US 4 271 557 A relates to a shock absorbing floor brush assembly for attachment with high-speed floor cleaning machines having a rigid brush disk movably mounted on a shock absorbing hub so that the brush disk rotates with a floating action. The shock absorbing hub is of smaller diameter than the brush disk and has a drive disk with a conventional attachment clutch plate mounted on its top side and fasteners surrounded by resilient material extending from its underside. These fasteners hold the rigid brush disk, when stationary, in parallel relationship with the drive disk but permit the brush disk to move upward during use. The particular construction of the floor brush assembly enables the resilient material to absorb the upward and torque shocks encountered when cleaning a floor and to return the brush disk to its parallel relationship with the drive disk without transmitting the shocks to the floor cleaning machine and its operator. The shock absorbing characteristics are adjustable and controllable by adjusting the fasteners to provide a predetermined steady state load on the resilient material.
US 2011/300784 A1 relates to a disk assembly for use with floor grinding and/or polishing machines. The disk assembly includes multiple cutting heads attached to a flexible rubber disk, and a layer of hook and loop type fastener material for attaching the disk assembly to the drive plate of the floor grinding and/or polishing machine. The disk assembly also includes a foam pad for attachment between the flexible polishing disk and the drive plate to provide additional support structure, and a rigid plate which can optionally be used between the flexible polishing disk and the foam pad to maintain a flat polishing surface.
US 8 105 134 B2 relates to a low pressure low speed concrete polishing apparatus and method of cleaning and polishing a floor used with a conventional rotary flooring machine. A polishing pad has interchangeable polymer strips that are slideably received within the housing of the pad. The polymer strips have an abrasive material embedded therein which collectively work to polish the floor while cleaning the floor during normal low speed floor cleaning conditions.

Summary

The invention for which protection is sought is defined by the independent claim. The dependent claims concern particular embodiments.
The present invention provides significant advancements or improvements over existing brush assemblies, and existing solutions for finishing concrete, terrazzo or other hard floor surfaces. The present invention provides a durable cleaning device that does not wear as quickly as a non-woven floor pad and provides increased durability for finishing rough floor surfaces. The present invention further allows for reduced waste and increased economy through providing for the individual replacement of brushes. Some aspects of the present invention also provide for a way to better clean or finish rough or uneven floors through the increased flexibility of individual brushes. Floors can be uneven due to an unfinished surface, grout lines, or gaps between tiles. The present disclosure provides a way to better clean these low spots in a floor. The present disclosure can provide cleaning and finishing consistency due to conformability of the individual brushes and bristles. The present disclosure also allows easy removal and replacement of a single broken or worn brush without requiring replacement of other brushes. Even further, the cushion pad compensates for a potential difference in height between the bristles on the new brush and the bristles on older brushes.
In one instance, the present disclosure includes a brush assembly comprising a cushion pad and a plurality of brushes secured to the cushion pad. The cushion pad has a 25% compressibility within the range of 6.9 kPa (1psi) to 2413 kPa (350 psi). At least one of the plurality of brushes comprises: a brush base, and bristles, the bristles comprising moldable polymeric material and abrasive particle additives.
In another instance the present disclosure includes a brush assembly comprising a cushion pad and a brush attached to the cushion pad. The cushion pad has a 25% compressibility within the range of 6.9 kPa (1psi) to 2413 kPa (350 psi). The brush comprises: a brush base, and bristles, the bristles comprising moldable polymeric material and abrasive particle additives.
In some instances, wherein the cushion pad has a hardness of less than 50 Shore A.
In some instances, the cushion pad has a relaxation modulus less than 25% according to the Relaxation Test.
In some instances, the cushion pad has a 25% compressibility within a range of 6.9kPa (1 psi) to 69 kPa (10 psi).
In some instances, the cushion pad is round.
In some instances, the cushion pad comprises a foam material.
In some instances, the cushion pad comprises at least one of: a non-woven material, a porous material, a fabric material, an inflatable material, and an elastomer.
In some instances, at least one of the plurality of brushes is secured to the cushion pad with a detachable attachment mechanism.
In some instances, the plurality of brushes are secured to a first major side of the cushion pad, and wherein the second major side of the cushion pad comprises an attachment mechanism.
In some instances, the plurality of brushes is in the range of 3 brushes to fifty brushes.
In some instances, the brush assembly is a floor cleaning and polishing assembly.
In some instances, the cushion pad is further mounted to a floor cleaning driver, and wherein the bristles on each of the plurality of brushes simultaneously contact a floor surface when pressure is applied to the driver, even when the length of the bristles varies.
In some instances, the abrasive particles comprise at least one of: diamond, aluminum oxide, silicon carbide, cerium oxide precision shaped grains, and agglomerates.
In some instances, the abrasive particles have a median particle size in the range of 1 microns to 10 microns.
In some instances, the brush assembly further comprises a backing pad, wherein the brush assembly is secured to the backing pad.
In some instances, the brush assembly is secured to the backing pad using a detachable attachment mechanism.
In some instances, the perimeter of the at least one of the plurality of brushes is circular.
In some instances, the perimeter of the at least one of the plurality of brushes is wedge-shaped.
In some instances, the bristles have a conical shape, wherein the circumference of the base of the bristle is larger than the circumference of the tip of the bristle.
In some instances, the bristle height is in the range of 5 mm to 25 mm.
In some instances, the brush base is molded such that it is integral with the bristles.
In some instances, the diameter of the bristles is in the range of about 0.75mm to 3.0 mm.

Brief Description of Drawings

The invention may be more completely understood when considered with the following detailed description in connection with the accompanying drawings, in which:

Figure 1 shows a cross-section view of a drawing of brush assembly with a plurality of brushes.
Figure 2 shows a top view of a drawing of a brush assembly with a plurality of brushes attached to the cushion pad.
Figure 3 shows a cross-section view of a drawing of a brush assembly.

The embodiments shown and described herein may be utilized and structural changes may be made without departing from the scope of the invention. The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

Detailed Description

Figure 1 shows a cross-section view of a drawing of brush assembly 100. Brush assembly 100 includes cushion pad 120 and a plurality of brushes 110. Brush assembly 100 may be used for a variety of cleaning, polishing or burnishing applications, including floor applications.
When brush assembly 100 is used in a floor application, attachment mechanism 124 can be used to secure brush assembly 100 to a driver of a floor cleaning machine. In such a configuration, brushes 110 face downward and come into contact with the floor. When a floor cleaning machine puts force on the driver (and thereby on the brush assembly 100), cushion pad 120 can provide flexibility to allow bristles 111 of brushes 110 to contact the surface of the floor even when the surface is uneven. Additionally, in some instances, the bristles 111 on each of the plurality of brushes simultaneously contact a floor surface when pressure is applied to the driver, even when the length of the bristles 111 varies. This configuration also allows for individual replacement of
Cushion pad 120 may be composed of a material selected according to softness. Softness of a material may be correlated with contact pressure and conformability of the material; generally, a softer material may have a lower contact pressure and a higher conformability. This softness may be represented by and selected for a variety of properties of the material of the cushion pad 120. For example, a softer material may be a material with a lower hardness (as indicated using any appropriate hardness scale, such as Shore A or Shore OO), a material with a lower elastic modulus, a material with a higher compressibility (typically quantified via a material's Poisson's ratio), or a material with a modified structure, such as containing a plurality of gas inclusions such as a foam, containing an engraved structure, etc.
In some instances, cushion pad 120 may be composed of a material selected according to hardness. Hardness may represent a measure of the relative change of a material in response to a force. In some instances, cushion pad 120 includes a material having a hardness of less than about 50 Shore A durometer (e.g., as measured using ASTM D2240), or less than about 20 Shore A, or less than about 10 Shore A.
In some instances, the cushion pad 120 may be composed of a material selected according to compressibility. Compressibility may represent a measure of the relative change of a material in response to a pressure, while the terms "compressible" or "incompressible" may refer to a material property of compressibility. For example, the term "substantially incompressible" refers to a material having a Poisson's ratio greater than about 0.45. Compressibility of a material may be expressed as a particular pressure required to compress the material to a reference deflection (e.g., 25% deflection). In some instancess, the compressibility of the cushion layer may be measured via Compression Force Deflection Testing per ASTM D3574 when the inner layer is foam; and via Compression-Deflection Testing per ASTM D 1056 when the cushion layer is a flexible cellular material such as, for example, sponge or expandable rubber.
In some instances, cushion pad 120 may have a compressibility at 25% deflection of less than 1.1 MPa (160 psi), less than about 45 psi, less than about 20 psi, or preferably less than about 10 psi. Cushion pad 120 may also have a compressibility at 25% deflection of more than about 1 psi. In some instances, cushion pad 120 may have a Poisson's ratio of less than about 0.5, less than about 0.4, less than about 0.3, or preferably less than about 0.2, or a negative Poisson's ratio.
In some instances, cushion pad 120 may be substantially incompressible, but sufficiently soft to provide the desired deformability. In some instances, the cushion pad 120 may be a layer made of substantially incompressible material which has been patterned, 3D printed, embossed, or engraved to provide the desired deformability.
In some instances, the cushion pad 120 may be composed of a material selected according to elastic deformation. Elastic deformation may represent an ability of a material to recover to its original state after being deformed. The material of cushion pad 120 may be elastically deformable, e.g., being capable of substantially 100% (e.g., 99% or more, 99.5% or more, or 99.9% or more) recovering to its original state after being deformed. In some instances, the cushion pad 120 may be compressible to provide the desired deformability. In some instances, the cushion pad 120 may be composed of a material selected according to relaxation modulus. Relaxation modulus may represent a measure of a time-dependent viscoelastic property. In this disclosure, relaxation modulus is measured according to the Relaxation Test described herein.
In some examples, the cushion layer has a relaxation modulus of less than 25% measured according to the Relaxation Test.
In some instances, the cushion pad 120 may be configured for various thicknesses. In some instances, the thickness of the cushion layer may in a range from about 0.125 mm (0.005") to about 20 mm (0.79"), or preferably from about 0.125 mm (0.005") to about 15 mm (0.59").
Cushion pad 120 may have various shapes and sizes. In some instances, cushion pad 120 may be round, quadrilateral, or any other shape that may be compatible with a cleaning device with which brush assembly 100 may be used.
The cushion pad 120 may be formed from a variety of materials having one or more properties discussed above. In some instances, the cushion layer includes at least one of a porous material, an inflatable material, an elastomer, a fabric, or a nonwoven material, or any combination of these materials. Suitable elastomers may include thermoset elastomers such as, for example, nitriles, fluoroelastomers, chloroprenes, epichlorohydrins, silicones, urethanes, polyacrylates, SBR (styrenebutadiene rubber), butyl rubbers, nylon, polystyrene, polyethylene, polypropylene, polyester, polyurethane, etc.
In some instances, the cushion pad 120 includes one of a foam, an engraved, structured, 3D printed, or embossed elastomer. A suitable foam may be open-celled or closed-celled, including, for example, synthetic or natural foams, thermoformed foams, polyurethanes, polyesters, polyethers, filled or grafted polyethers, viscoelastic foams, melamine foam, polyethylenes, cross-linked polyethylenes, polypropylenes, silicone, ionomeric foams, etc. The cushion layer may also include foamed elastomers, vulcanized rubbers, including, for example, isoprene, neoprene, polybutadiene, polyisoprene, polychloroprene, nitrile rubbers, polyvinyl chloride and nitrile rubber, ethylene-propylene copolymers such as EPDM (ethylene propylene diene monomer), and butyl rubber (e.g., isobutylene-isoprene copolymer). In some instances, the cushion pad 120 may include various compressible structures. For example, the cushion pad 120 may include any suitable compressible structures such as, for example, springs, nonwovens, fabrics, air bladders, etc. In some instances, the cushion layer may be 3D printed to provide desired Poisson's ratio, compressibility, and elastic response.
The plurality of brushes are secured to cushion pad 120 using attachment mechanisms 122 and 112. Attachment mechanism 112 is adhered, secured, or otherwise attached to the back of brush 110. Attachment mechanism 122 is adhered, secured or otherwise attached to a major surface of cushion pad 120. Attachment mechanism 112 and 122 can be configured such that they mate with each other. Attachment mechanisms 112 and 122 can be detachable attachment mechanisms, such that they can mate with each other, but can also be detached from each other. This allows removal and replacement of an individual brush 110 on cushion pad 120. Examples of specific types of attachment mechanisms include hook and loop, Dual-Lock^™ reclosable fasteners sold by 3M Company of St. Paul, Minnesota, a slot mechanism, mechanical fasteners and other attachment mechanisms as will be obvious to those of skill in the art upon reading the present disclosure. In some instances, brushes 110 are attached to the surface of cushion pad 120.
The number of brushes 110 attached to cushion pad 120 may vary. As shown in Figure 1, the number of brushes attached to cushion pad 120 may range from three brushes to fifty brushes.
Brushes 110 include a brush base and bristles, the bristles comprising moldable polymeric material and abrasive particle additives. The type and size of abrasive particles can be chosen based on the desired level of abrasion or polishing. In some instances, the abrasive particles include at least one of: diamond particles, aluminum oxide, silicon carbide, cerium oxide, precision shaped grains, agglomerates.
The abrasive particles may have a variety of sizes. For example, they may have a median particle size in the range of 0.1 to 1,000 microns. In another instances, they may have a median particle size in the range of 1 micron to 10 microns.
Types of moldable polymeric material that may be used consistent with the present disclosure include, for example, a thermoplastic polymer, or a thermoplastic elastomer.
Examples of thermoplastic polymers include polycarbonate, polyetherimide, polyester, polyethylene, polysulfone, polystyrene, polybutylene, acrylonitrile-butadiene-styrene block copolymer, polypropylene, acetal polymers, polyurethanes, polyamides, and combinations thereof.
Thermoplastic elastomers are generally the reaction product of a low equivalent weight polyfunctional monomer and a high equivalent weight polyfunctional monomer, wherein the low equivalent weight polyfunctional monomer has a functionality of at most about 2 and the equivalent weight of at most about 300 and is capable of polymerization of forming a hard segment (and, in conjunction with other hard segments, crystalline hard regions or domains) and the high equivalent weight polyfunctional monomer has a functionality of at least about 2 and an equivalent weight of at least about 350 and is capable on polymerization of producing soft, flexible chains connecting the hard regions or domains. Examples of thermoplastic elastomers include segmented polyester thermoplastic elastomers, segment polyurethane thermoplastic elastomers, segmented polyamide thermoplastic elastomers, blends of thermoplastic elastomers and thermoplastic polymers, and ionomeric thermoplastic elastomers. Other examples of suitable moldable polymeric materials can be found United States Patent 6,126,533 to Johnson et al .
Brushes 110 can have various shapes and sizes. In some instances, the perimeter of at least one of the plurality of brushes 110 is circular. In some instances, the perimeter of at least one of the plurality of brushes 110 is wedge-shaped. Other known shapes will be apparent to one of skill in the art upon reading the present disclosure.
Brush bristles 111 may have a conical shape, wherein the circumference of the base of the bristle is larger than the circumference of the tip of the bristle. The height of brush bristles may range as well. For example, bristle height may be about 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, or in a range between any two of the preceding values. The diameter of bristles 111 can also range. For example, bristles 111 may have a diameter of about 0.5 mm, 0.75 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm, or in a range between any two of the preceding values.
In some instances, bristles 111 may be attached or secured to a brush base. In other instances, bristles 111 may be integrally molded with a brush base.
In some instances, brush assembly 100 further comprises an attachment mechanism 124 on the major surface of cushion pad 120 opposite brushes 110. Attachment mechanism 124 can be used to attach cushion pad 120 to a driver on a floor cleaning machine or on another cleaning device. Examples of types of materials or devices that may be used for attachment mechanism 124 include hook and loop, Dual-Lock^™ reclosable fasteners sold by 3M Company of St. Paul, Minnesota, slot fasteners and other mechanical fasteners. Other attachment mechanisms will be apparent to one of skill in the art upon reading the present disclosure.
Figure 2 shows a top view of a drawing of a brush assembly 200 with a plurality of brushes 210 attached to cushion pad 220. As shown in Figure 2, brushes 210 have a wedge shape. However, in other instances, brushes 210 may have a round, quadrilateral, trapezoidal, triangular, or irregular shape.
Figure 3 shows a cross-section view of a drawing of a brush assembly 300. Brush assembly 300 includes a cushion pad 320 and a single brush 310 attached to cushion pad 320. The brush 310 comprises a brush base and bristles 311, the bristles 311 comprising moldable polymeric material and abrasive particle additives. In the instance illustrated in Figure 3, cushion pad 320 is disposed below a single brush 310, and multiple brush assemblies 300 may be attached to a single driver pad of a floor cleaning machine. Alternatively, a single cushion pad 320 with a larger single brush 310 could be attached to a driver pad of a floor cleaning machine.
The components shown in Figure 3, including cushion pad 320, brush 310, bristles 311, attachment mechanisms 312, 322 and 324 can have the same materials, characteristics and features as other parallel components discussed herein.

Relaxation Test

Stress relaxation characteristics are measured using ASTM D6048. Sample materials of the cushion pad are loaded and held under a constant compressive strain (e.g. as change in the sample thickness divided by its original, non-deformed thickness) in a standard mechanical testing load frame. The force applied by the sample to the testing machine platens is measured and recorded continuously along with the corresponding elapsed time from the beginning of the test during each test. Stress is then calculated for each sample as the corresponding applied load divided by the cross section of the sample placed on the platens of the testing machine. The modulus was calculated by dividing the stress to constant strain for each sample.
This process is summarized by the following steps:

Step 1: A constant strain is applied to the sample.
Step 2: Force applied by the sample to the testing frame is recorded continuously during the test.
Step 3: Stress (σ) is calculated from the recorded force using the following equation: $σ (t) = Force (t) / Sample' s cross section area$
Step 4: Modulus (E) is calculated by dividing stress (σ) by the constant strain (ε_c), using the following equation: $E (t) = σ (t) / ε_{c}$
Step 5: Relaxation Modulus (%) is calculated using the following equation: $Modulus relaxation (%) = [(E_{0} - E_{2}) / E_{0}] * 100$

Where E0 is the instaneous modulus and E2 is the modulus after two minutes of relaxation of the sample material under constant compressive strain.

Claims

A brush assembly (100, 200, 300) comprising:
a cushion pad (120, 220,320) having a compressibility at 25% deflection within the range of 6.9 kPa (1 psi) to 2413 kPa (350 psi);

a brush (110, 210,310) attached to the cushion pad, wherein the brush comprises: a brush base, and bristles (111, 311), the bristles comprising moldable polymeric material and abrasive particle additives.
The brush assembly of claim 1, wherein the cushion pad (120, 220, 320) comprises at least one of: a non-woven material, a porous material, a fabric material, an inflatable material, and an elastomer.
The brush assembly of claim 1, wherein the perimeter of the at least one of the plurality of brushes (110, 210, 310) is circular.
The brush assembly of claim 1, wherein the perimeter of the at least one of the plurality of brushes (110, 210, 310) is wedge-shaped.
The brush assembly of claim 1, wherein the bristles (111, 311) have a conical shape, wherein the circumference of the base of the bristle is larger than the circumference of the tip of the bristle.
The brush assembly of claim 1, wherein the brush base is molded such that it is integral with the bristles (111, 311).
The brush assembly of claim 1,
wherein a plurality of brushes (110, 210) is secured to the cushion pad (120, 220), wherein at least one of the plurality of brushes comprises: a brush base, and bristles (111), the bristles comprising moldable polymeric material and abrasive particle additives.
The brush assembly of claim 7, wherein the cushion pad (120, 220) has a hardness of less than 50 shore A.
The brush assembly of claim 7, wherein the cushion pad (120, 220) has a relaxation modulus less than 25% according to the Relaxation Test.
The brush assembly of claim 7 wherein the cushion pad (120, 220) comprises at least one of: a non-woven material, a porous material, a fabric material, an inflatable material, and an elastomer.
The brush assembly of claim 7, wherein the at least one of the plurality of brushes (110, 210) is secured to the cushion pad (120, 220) with a detachable attachment mechanism (112, 122).
The brush assembly of claim 7, wherein the plurality of brushes (110, 210) are secured to a first major side of the cushion pad (120, 220), and wherein the second major side of the cushion pad comprises an attachment mechanism (124).
The brush assembly of claim 11, wherein the cushion pad (120, 220) is further mountable to a floor cleaning driver, and wherein the bristles (111) on each of the plurality of brushes (110, 210) are configured to simultaneously contact a floor surface when pressure is applied to the driver, even when the length of the bristles (111) varies.
The brush assembly of claim 7, wherein the abrasive particles comprise at least one of: diamond, aluminum oxide, silicon carbide, cerium oxide, precision shaped grains, and agglomerates.
The brush assembly of claim 7, wherein the abrasive particles have a median particle size in the range of 1 microns to 10 microns.