Patent Application
20240418194
The present invention relates to an apparatus and a method for mounting objects onto a hollow wall or hollow ceiling outer surface using an adhesively affixed recessed back plate.
Methods of mounting objects onto hollow wall materials, such as gypsum board, wood panel, or cement board, are known. Prior art methods have employed, for example, devices such as toggle bolts, plastic anchors, or expanding shielded inserts. While spring loaded folding bi-winged toggles have enjoyed widespread use as hollow wall mounting devices, they nevertheless suffer shortcomings and disadvantages. Spring loaded toggle bolts, such as described in U.S. Pat. No. 2,013,503 by Pleister, and incorporated herein in its entirety by reference thereto, lack the ability to retain the rear face securing component if one removes the mounting screw when wishing to attach a different object. In such a device, the bi-winged folding head component falls away into the hollow wall cavity. Additionally, the spring toggle bolt device often requires the screw or bolt component to be threaded through the object to be mounted during passage of the toggle through a drilled wall aperture. Thus, in the case of a bi-wing spring toggle bolt, a sizeable or heavy fixture that requires multiple toggle style wall anchors, can be quite cumbersome when one wants to properly position multiple spring-loaded devices while aligning heavy objects. Moreover, the U-shaped profile of a spring-loaded bi-fold toggle device presents knife-like deformation to the rear surface of a hollow wall material, arising from the concentrated stress exerted by the edges of the toggle metal rails against a material such as gypsum drywall. Such concentrated forces compress or indent the wall material resulting in decreased firmness. To restore the desired firm tension, retightening of the toggle bolt is required to preserve its intended purpose. Progressive deformation creep resulting from continued re-tightening can lead to failure of the toggle head at its fold hinge or may result in wall board failure. At times, the toggle head wings may severely deform, tear, or even die-cut a friable wall material. In the case of heavy objects such as a mirror, one may select a relatively large toggle in an effort to decrease deformation tendency, however, such larger toggle selection results in exceptionally large wall openings that are difficult to repair when changing the room design.
Expanding screw shield wall anchors, such as split tip plastic screw sleeves, have also enjoyed widespread usage. However, these types of inserts have the disadvantage of degrading the inner surfaces of the wall material, especially gypsum board, when supporting heavy objects or objects that are frequently grasped. Additionally, sleeved screw wall anchors remain embedded in the wall board after removal of a mounting screw, thereby leaving a flange projecting from the wall board outside surface, thereby preventing filling and sanding the surface without extracting the bulging flange. Moreover, practitioners recognize such shielded screw inserts as gradually enlarging the desired wall bore in response to heavy load or cycles of loading and unloading, resulting in the increased downward deflection, or “tipping” of a mounted object. Such repeated loading and unloading may result in catastrophic dislodgement of the shielded screw from drywall due to degraded mineral filled gypsum board. Once such mechanical damage occurs, it is difficult to retroactively secure and realign the insert. Of general interest are wall mounting devices such as those described in U.S. Pat. No. 5,190,425 to Wieder et al. or U.S. Pat. No. 7,261,505 to Ernst et al., each incorporated in its entirety by reference thereto.
Therefore, a need exists for hollow wall mounting devices that overcome the deficiencies of prior art methods such as spring-loaded toggles that tend to cut into wall board and which fall away when the mounting bolt is removed, as well as plastic split-tip shielded screw inserts that tend to loosen, dislodge and severely degrade friable gypsum board, or which leave a prominent flange or collar disrupting the wallboard outer surface planarity after removing a mounting screw.
It is the general object of the present invention to provide a recessed wall mounting device, suitable for mounting objects onto hollow wall materials, such as for example, mirrors, shelves, handrails, grab bars, towel bars and other items, without the shortcomings of known prior devices.
Another object of the invention is to provide a self-supporting and recessed device for mounting an object along the front face of a hollow wall material, without the device component protruding beyond the front wall surface. Such a recessed, or flangeless, mounting device would result in quicker restoration of the wall face when the mounting location is changed.
Another object of the present invention is to provide a device and a method for mounting objects onto a hollow wall material which includes a self-supporting rear mounting plate with a planar or substantially planar surface contact profile, that is inserted end-on through an aperture of a hollow wall material, wherein the mounting plate is adhesively affixed to the back face of the hollow wall material, thereby providing an affixed, self-supporting rear wall mounting base. In this embodiment, the rear mounting plate inner surface is preferably adapted via machining, stamping, etching, or molding to enhance the retention of a deposited liquid adhesive to the plate's planar inner wall contact surface prior to adhesive curing, as well as post cure. Plate surface adaptions include, but are not confined to indentations, conical recesses, milled or drilled cavities, hemispherical recesses, wells, channels, chemical etchings, laser cut features, and cross hatching. Those having ordinary skill recognize that other textural adaptations along the inner plate surface topography may be performed to improve adhesive retention and inner plate bonding. Such additional inner plate surface adaptions are within the scope of the present invention.
Yet another object of the invention is to provide a recessed securing means to engage an object mounting screw. Several securing means are contemplated and tested by the inventor and described in greater detail in the embodiments and drawings herein. Securing means are incorporated into or alternatively are coaxial with the primary bore of the back plate. Securing means include threads tapped directly within the back plate primary bore. Other securing means may include a threaded nut, coaxial with the primary bore, and incorporated, for example, along the outer surface of the back plate, or within a recess within the bore cavity. Another securing means includes a double threaded sizing bushing. This sizing bushing may be described as a hollow cylinder having exterior shaft threads to engage back plate primary bore threads and interior surface tapped threads to engage mounting screw threads of a different caliper than the bore threads of the affixed back plate. In this embodiment, the sizing insert bushing may be changed to provide securing threads to engage a selected mounting screw, whether the mounting screw is a machine type thread or a wood type thread. Still other securing means include a dowel pin that is mounted with the primary bore cavity wherein the dowel is equipped with female thread to engage a mounting screw. In the case of the dowel embodiment, the dowel serves as an axle that is mounted within depressions or secondary bores located perpendicular to the direction of the back plate primary bore, along the primary bore cavity inner walls to permit the dowel to pivot perpendicular to the plate long axis.
Still another object of the invention is to provide a means of grasping the back wall mounting plate during end-on insertion, post insertion alignment, and adhesive tensioning of the mounting plate inner surface to the rear face of a hollow wall material. Grasping means are preferably released or disengage after adhesively affixing the back plate to the rear wall face. Grasping means include fiber or polymer strand lanyards attached to the back plate using engineered through-holes and secured to the back plate with such as loops, knots, or glue. Such strands are attached outboard of the back plate primary bore and may be used to provide tensioning force to urge the back plate into firm contact with the hollow wall back face. Other grasping means include detachable hand tools with a pivoting end component to enable end-on plate insertion, post insertion alignment, and to apply tension to enhance bonding between the adhesive and the rear surface of the wall material. Such hand tool grasping means include end threads adjacent to the pivot, as well as a tab to twistably engage a slot positioned within the back plate bore wall. Still other grasping means include a threaded rod or a mounting screw. In this instance, the back plate bore is equipped with a pivoting cylinder orthogonal to the bore and mounted perpendicular to the long axis of the back plate. The pivoting cylinder includes tapped threads to engage a mounting screw or threaded rod.
Another object of the invention is to provide a kit for recessed mounting of objects onto a hollow wall, the kit including:
After diligent trials, the inventor has combined an adhesive with, a single member, contiguous back plate, the back plate including a primary bore equipped with tapped threads to engage a mounting screw, to thereby provide a self-supporting and recessed wall mounting device that eliminates many of the deficiencies of common prior art devices, such as loss of firm attachment upon cyclic loading and unloading, loss of mounting device when removing the mounting screw, and damage to friable wall material by device impingement. These and other objects and advantages provided by the present invention are set out within the specification, the drawings, and claims herein.
As used herein, the term hollow wall material refers to a plurality of construction materials and positions. Hollow wall materials are utilized in a number of construction applications in which the board-like product is attached to load bearing or partition members, but which result in hollow regions between members. Those having ordinary skill in the art recognize that hollow wall materials include gypsum “dry wall,” wood panel, composite panel, concrete panel, and the like. Gypsum board often refers to a friable center mineral laminated between two outer layers of paper or film. The term wall is herein intended to refer to bottom, top or side room positions, and thereby includes ceiling, side walls, and floor applications.
As used herein, the term single member mounting plate regards a back mounting plate that is formed from a single, planar contiguous piece of material rather than any multi-part mounting device such as certain prior art bi-folding devices, particularly prior art bi-winged toggle style folding devices. The contiguous plate described herein exhibits a planar contact surface that is divided into first and second segments by a primary bore positioned approximately midway along the long axis. In the present application, the term “substantially planar” is used to include back plate planar inner surface contact profiles that may also include certain adaptations to the flat profile such as machined channels for tool nesting, depressions for adhesives, wells for adhesives, and an array of surface adaptations which are intended to improve the retention of adhesives, such described within this specification. Preferred plate materials are referred to as rigid raw materials, thereby exhibiting substantially no defection in response to the load imparted by the mounting screw. The term rigid is herein intended to distinguish from certain prior art materials which readily deform during wall aperture insertions of which will deflect upon loading, such as for example, thermoplastic nylons and polyolefins Examples of rigid mounting plate materials include such substances as metal, wood, ceramics, thermosetting plastics, or plastics having a Vicat softening point above about 70 degrees Celsius, such as, for example ABS or thermosets. Back plate materials may be manufactured from a rigid material selected from the group consisting of metal, wood, ceramic, ABS, thermoset polymers, and plastics exhibiting a modulus of elasticity greater than 700 MPa at 23 degrees Celsius when tested in accordance with ASTM D 747.
As used herein, the term recessed refers to a device that resides behind the front plane of the wall material. The recessed device of the invention does not require any device component that projects above the front face of the wall material in order to become self-supporting. Those having ordinary skill in the art recognize, however, that certain objects to be mounted using the recessed plate devices of the invention may present a component that could reside above the wall plane, however, the addition of a such a front surface object component, such as a bracket, base, or extension collar, is not required for the device of the invention to be self-supporting.
As used herein, the term tensioning tool refers to a tool that engages with the primary bore, or alternatively adjacent to the primary bore of the single member contiguous mounting plate so as to serve as a grasping means to insert, align, and urge the plate into firm contact with the rear face of hollow wall material during the adhesive bonding of the plate to the rear wall surface. Tensioning tools preferably include pivot point adjacent to the end engagement tooling so as to permit approximately a 90-degree pivoting of the contiguous mounting plate along the plate long axis during end-on insertion through a wall aperture and subsequent return to a “T” conformation during the step of adhesively affixing the plate inner surface to the rear wall surface when an adhesive is disposed onto a segment of the plate inner surface that is outward of the primary bore. In some embodiments, the tool may engage directly with female threads provided within the plate bore or communicating with the bore cavity. The tool may also twist engage with one of more slots along the bore cavity or the outer surface of the back plate to temporarily engage the plate with the tooling end effector, in a lock and key or bayonet manner.
As used herein, the term sizing insert refers to a double-threaded reducing or enlarging bushings that may be used to modify the opening thread size that is engineered into a plate bore. Double threaded sizing bushings, also double threaded reducing bushings, may be described as cylinders having first outer male threads and a bore housing second inner female threads. Such sizing inserts may be advantageously used to reduce or modify the gage or the pitch of plate primary bore threads or dowel threads in order to receive an array of different diameter or pitch mounting screw threads. Sizing bushings may directly engage threads within the back plate bore, may engage the threads of an affixed nut, or may engage the threads of pivoting dowel located within the back plate bore cavity when such dowel is installed perpendicular to the primary bore axis and pivots along the plate long axis.
Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings.
The invention includes a self-supporting mounting plate, also referred to as a back plate, which is adhesively mounted within a hollow wall material along the rear surface of the wall board. Wall apertures may assume many geometries including circular bores, slots, or irregular opening geometries. Upon insertion through a hollow wall opening, the back plate may be positioned in any number of orientations along a 180-degree axis ranging from horizontal to vertical. Such freedom of orientation permits placement of the back plate in inner wall environments where unseen inwall components may otherwise interfere. The self-supporting mounting plate preferably includes inner surface modifications to improve retention and attachment of an adhesive deposit, provided by chemical etching, channels, cross hatching, and recesses. The plate enables engagement with grasping means during insertion of the plate through a wall aperture so as to subsequently urge the plate into firm contact with the rear wall surface contact.
Grasping means may include at least one additional through hole other than the primary bore hole within the mounting plate through which a strand or lanyard, such as monofilament nylon line, may be threaded to secure and pull the plate into firm contact with the rear wall surface. In this embodiment, an adhesive is deposited along the inner surface of the plate outboard of the primary bore and fiber through-holes. The plate is inserted end-on through the wall slot or hole and stranded grasping means are used to guide the plate and to apply tension so as to urge the plate into firm contact with the rear surface during adhesive bonding. The fibrous strand may thereafter be detached from the affixed back plate. Other grasping means include special tools to temporarily attach to the back plate and readily detach after the adhesive has affixed to the rear wall surface and the back plate becomes self-supporting.
A variety of self-supporting back plate geometries and plate materials are included within the scope of the present invention. Unlike many prior art hollow wall mounting methods, the back plate of the invention may be positioned within the hollow wall and adhesively attached, independent of any mounting screw. Relevant mounting plate materials include metal, thermoplastic polymers, thermoset polymers, and wood. Back plate materials preferably include inner surface modifications to enhance mechanical adhesion to a deposit of adhesive. In the case of a thermoplastic injection molded back plate, the planar inner, wall contact surface includes adaptions such as channels, depressions, pips, wells, crosshatching, chemical etching, laser etching and similar adaptions. Irrespective of the material type, back plate inner surface modifications enhance the retention of an adhesive deposit during the installation of the plate through the wall opening and help retain the adhesive during alignment and pulling the back plate into firm contact with the rear wall face. Back plate inner surface adaptions help retain a deposit of adhesive so as to reduce dripping, in the case of a deposit of a liquid adhesive, during the insertion and bonding to the wall rear face. Inner surface adaptions ensure that an adequate deposit of adhesive is provided to ensure good bonding to the hollow wall rear face.
In the case of an injection molded back plate, surface features may be conveniently molded into the inner surface to enhance adhesive acceptance upon the inner surface. For example, engineered surfaces may be molded to meet industry standard, SPI Grade D-3 with a Ra of 3.20 to 18.0 μm. Grade D-3 and other surface adaptions may be attained using drilling, sanding, laser etching, chemical etching, or EDM.
It is preferred to restrict the location of an inner plate surface adhesive deposit to the region of the plate surface outward of the plate's primary central bore and through-hole grasping means. Adhesive-retaining surface features help direct the user to deposit adhesive away from, or outboard of the back plate primary bore threads or pivoting hinge engagement and instead deliver adhesive upon modified mounting plate inner surface adaptions. Locational restriction ensures that no adhesive interferes with grasping means or securing means.
One back plate geometry includes a rectangular contact inner surface whose thickness is substantially less than its length. This quadrilateral bar-like design facilitates end-on insertion through a small wall aperture and provides strong mechanical performance owing to its span after aligning along the wall inside surface. Other contiguous planar back plate geometries conceived herein include “S” shaped, fan-shaped, boomerang shaped, bow-tie shapes, or other contiguous component geometries that extend from a primary bore within the plate. In the case of fan blade or curved geometries, distal elements may be symmetrical or asymmetrical relative to the primary bore. The objective of all single member, or contiguous back plate designs is to deliver maximum surface area along rear wall surface whilst keeping the end-on wall insertion aperture small. The exceptionally strong mounting strength of the inventive back mounting plate overcomes mechanical weaknesses of many prior art wall inserts such as the split component wall anchors. It is useful to provide a plate whose length that is about 4 times to about 12 times greater than the thickness, such as about 4 times to 8 times greater than the plate thickness. Plate length is limited by the cavity depth within the wall and may restrict the plate length from about 3 inches to about 5 inches. In contrast to the plate inner, wall contact surface, the back plate outer, or rear surface may have geometries the same as or different from that of the substantially planar inner surface. For example, the back plate outer surface may be convex or hemispherical to assist with insertion and orientation. For example, the plate outer surface geometry may be a longitudinally truncated cylinder, half cylinder, or turtle back shaped.
Adhesives useful in affixing the back plate of the present invention to the wall rear surface include glues, epoxies, cements, and pressure sensitive adhesives, intended for bonding metal to wood, wood to paper, or construction adhesives. Preferable adhesives include pressure sensitive adhesives, epoxies, acrylic adhesives, and self-curing adhesives. Pressure sensitive adhesive (PSA) is a classification of non-reactive adhesives which advantageously rapidly adhere to an opposing surface upon compression contact. No solvent, water, or heat is needed to activate the adhesive. Adhesion to the plate, rapid high shear force bonding, adhesion to low surface energy materials and vibration control are desirable properties for the invention. Pressure sensitive adhesive exhibit with high shear resistance when applied to a surface, in particular to the backside of diverse types of wall board such as drywall and wood. The PSA may be applied by the user or applied robotically during a manufacturing process, and then protected by a removable film. Curing adhesives include polyurethane adhesives which react with moisture and increase viscosity in the presence of ambient moisture. Preferred curing adhesives reach useful set viscosity within 30 minutes to one hour, such as about 45 minutes after deposit. Preferable adhesives include chemistries that expand during curing to improve bonding by filling void spaces between the wall surface and the inner surface of the mounting back plate. Characteristics of useful adhesives include room temperature cure, thixotropy, sag resistance, low clamp time or rapid curing, and gap filling. Applicable polymeric materials include two-part epoxy, hot melt adhesives such as EVA, silyl modified polymer (SMP), polyurethane, polyacrylate, pressure sensitive adhesives, co-polyamides, and emulsion polymer isocyanates.
Adhesive sources include Bostik, Franklin Adhesives and Polymers, Titebond, the Gorilla Glue Company, Loctite, TMI Products (Stick Fast™), Mercury Adhesives, Satellite City Adhesives, and Master Bond Inc. Specific reactive adhesive examples include, Titebond Polyurethane Liquid Glue, Vibra-Tite 224 High Impact Structural Adhesive, Bostik Supergrip® 1582-082, Bostik Born2Bond™ Flex, Bostik Grip N Grab™, Bostik Pro-Cure™ Moisture-Cure Urethane Adhesive, Gorilla Construction Adhesive, and PPG Liquid Nails FUZE*IT® All Surface Construction Adhesive (LN-2000). One useful adhesive is a polymeric moisture reactive product such as a self-curing adhesive that is available from the Gorilla Glue Company, Cincinnati, Ohio. Pressure sensitive adhesive sources include 3M Corporation, Lenderlink, Toyo Ink America LLC, Shurtape Technologies, Gorilla Glue Company Henkel AG and Co., and Avery Dennison.
The inventive mounting device includes a grasping means to insert and align the back plate, such that an adhesively loaded back plate may be correctly located, and the primary plate bore may be optimally positioned within the wall aperture. Grasping means may include a second set of threads located concentric with the securing threads of the back plate primary bore but with a larger diameter stepped outside the primary securing threads. In such embodiments, the second set of threads are shallow with respect to the primary through-plate bore, and which are used as a temporary securing means during the step of affixing the adhesive. A pivoting thread-ended tool may be used to engage threads tapped into the primary bore or alternatively second larger partial bore, similar to a counter sink arrangement. In such alternate grasping means, a tool is attached using the outer diameter threads during insertion and adhesive affixing, then disengaged to reveal the primary bore threads that function to secure the mounting screw. Such tools comprise a handle, attached at a first end of a rod, a hinged joint proximate to the second end of the rod, the joint having the outermost end equipped with a threaded screw extension. The tool screw extension may thus engage threads within the primary plate bore or secondary plate countersink bore to provide grasping means which may be disengaged from the plate after adhesive bonding. The tool may further include threads along the rod body to engage a cylinder or nut to maintain back plate force during adhesive bonding. Additional grasping means include detachable hand tools equipped with a pivoting threaded end segment to directly engage portions of the plate. Such grasping tools may engage a slot, notch, or channel adjacent to the primary bore, or along the plate edge or outer surfaces. Such tools include pivoting twist locks, bayonet-style gripping tools, and detachable telescoping hooks or clips. Still other grasping tools include adapted scissor-like tools, such as modified alligator surgical forceps, or normally open split ring pliers. Grasping tools may be retracted after adhesively bonding the back plate. It is recognized that prior to adhesive bonding, the center bore of the plate is aligned such that it is approximately concentric with a drilled wall opening or at the desired mounting location of a slot opening.
Another grasping means includes one or more plate through-holes, located outboard from the plate primary bore through which fiber strand loops or ties are attached. Strand and cord lanyards are advantageously located adjacent to the plate center bore. Once the plate is inserted, the attached strands are sufficiently long as to extend through the wall aperture and beyond the front face of the wall material to permit tension to be applied to firmly urge the inner plate surface into contact with the rear face of the wall board. Clips or other convenient tools may be used to retain tension on the fiber strand or strands during adhesive bonding such as in the case of curing proceeds. Optionally, a probe may be used to assist with desired aligning of the back plate primary bore or to assist with the detachment of the fiber strand. One preferable fiber strand material is monofilament nylon, due to its high tensile strength. However, other fibers may be useful in carrying out the objects of the invention, including an ultra-high molecular weight polyethylene, such as Dyneema™. After affixing the back plate to the hollow wall rear surface, protruding fiber length may be severed or pulled out from plate through-holes and discarded. Monofilament may be successfully withdrawn even if an expanding curable adhesive partially envelops the strand.
Securing means are incorporated within the bore of the back plate. The plate primary bore includes securing means such as primary bore threads, an affixed threaded nut, or a polymer insert to engage a threaded mounting screw. Other securing means include a hollow cylinder having outer threads to engage the plate primary bore threads and inner threads to engage the mounting screw. In the case of a back plate produced from a metal such as steel, a threaded insert similar to a conventional nut may be bonded to the outer surface of the back plate and concentric with the bore. For example, in the case of a nut, a recess may be machined or molded into the back plate to receive and adhere the nut using methods such as welding, crimping, gluing and the like. In such embodiments, when the back plate is inserted and adhesively affixed to the rear wall surface, the mounting screw may engage the bonded nut without the possibility of pulling the nut through the bore. Following the disposition of an adhesive, such as a moisture curing adhesive, onto the inner surface of the back plate, and outboard of the plate center bore, the plate may be inserted through a wall aperture and thereafter pulled into firm alignment using grasping means. In the case of a pressure sensitive adhesive, the bonding adhesive surface is preferably protected by a cover film until peeled away to activate the bonding surface.
As described herein, the invention provides a method of mounting an object onto the front face of a hollow wall, the method comprising:
Referring to
Example 2 illustrates another embodiment in accordance with the invention.
Referring to
This example describes two means of grasping the back mounting plate that are within embodiments of the invention. Two pivoting grasping tool end types, or end effectors are hereafter described together with mating back plate bore geometries. Referring to exploded diagram
Grasping tool end 200 is now described. Grasping tool outer end 201 may be fixed to a simple handle or coupled to a hand tool by way of screw or hand tools that are designed for snap coupling to accept different end fittings. Tool 200 includes outer end 201 attached to a first end of a pivot hinge 203, and a key end 202 attached to a second end of pivot hinge 203. Key end 202 includes prong 205. In this illustration, outer tool end 201 includes a bore and tapped threads 204 that may be attached to hand tool knob 215, by way of threaded rod 216. When tool 200 is grasped using an attached handle, it would be pressed into twist slot 105 of plate 110 and then twisted to provide a disengageable means of grasping back plate 100. Optionally, wing nut 217 and bar 218 may be employed to provide front wall surface tensioning following plate insertion when a disposed adhesive along surface 101 is affixed. Once tool 200 is attached to back plate 100, adhesive would be deposited upon adapted surface areas 103 of plate inner surface 101. Once attached, the back plate may be pivoted about the hinge within 203 to permit end-on insertion of plate 100, through a predrilled aperture (not illustrated) in a hollow wall material. Following insertion into hollow wall cavity, the back plate may again be pivoted to return the engagement angle between tool 200 and plate 100 to assume a more perpendicular conformation. The back plate would be tensioned into firm contact with the rear surface of a wall material using handle knob 215 and held under tension until the adhesive deposit achieves self-supporting bond strength. Tool 200 is thereafter disengaged to reveal female threads within bore 110 of the self-supported back plate 100. Female threads tapped within the bore walls of the recessed affixed plate 100 are thereafter prepared to engage an object mounting screw when wishing to mount an object along the hollow wall front surface.
In
Referring to
Referring to
Having described the invention through drawings and examples, it should be recognized that modifications and variations to exemplar embodiments herein disclosed will be understood by those having skill in the art. Specific examples are illustrative rather than representing any limitations or the invention. The scope of the present invention is limited only by the appended claims.
