Abstract:
Doorway or passageway arches and a mold and method for making doorway arches, wherein the arches comprise pre-fabricated plaster, two sides that are substantially perpendicular to each other, a concave arcuate side extending between the sides and flanges extending outward from each side for securing the arch to adjoining walls defining a comer, and the mold comprises a base, at least two perpendicularly disposed slots, at least one slidably insertable and removable board for each slot, a mold projecting upward from said base and having a convex side extending between opposing ends of said boards, flanges disposable along the boards and a volume for receiving a hardening agent, such as plaster.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     N/A 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     N/A 
     COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights rights whatsoever. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to doorway or passageway arches and a mold and method for making doorway arches, and more particularly, to a pre-fabricated plaster arch having exposed flanges that allow it to be easily installed in any doorway and a mold and method for making plaster arches that allows plaster arches to be completely made prior to installation. 
     2. Description of the Background Art 
     The construction of arches in doorways, or passageways, can be tedious, expensive and time-consuming work. In fact, this type of work invariably has to be done by a trained carpenter. The construction of arches typically involves cutting plywood and drywall into the desired semi-circle arched shape, making cross-members (usually from 2×4 studs) for securely joining the plywood in a manner that corresponds to the thickness of the passageway wall, securing the plywood to the cross-members to form the framework, mounting the drywall to the plywood, attaching comer beads, taping all seams, and floating or filling the seams. Some pre-framed arches are known in the art, however, they are not complete. That is, they still require the use of plaster or stucco, drywall, tape, floating and comer beads, and can be difficult to install. There are no known devices, molds or methods that allow a plaster arch to be made before installation so that it only needs to be mounted to the comer of the passageway and made flush with the wall. A pre-fabricated plaster-based arch would help carpenters save time and customers save money and could be installed by non-professionals as well. Consequently, a device or method for simplifying the construction of passageway arches would be well received. 
     Several arch members and methods for making arches are known in the background art. However, none of these addresses or solves the above-noted problems associated with making and mounting arches. The patent references found fail to disclose important structural elements of the instant invention. For instance, U.S. Pat. No. 1,782,147 discloses a metal arch member for openings comprising a box-like arcuate member that is mounted to a comer of a doorway for adhering plaster. U.S. Pat. No. 1,931,889 discloses a metal cove and bracket for producing an arcuate cove between a wall and ceiling. U.S. Pat. No. 2,344,279 discloses a plastering base comprising a pre-formed base strip for attachment to doorway studs and applying plaster. U.S. Pat. No. 2,442,929 discloses an arch member for openings comprising a support or base adapted to be covered with plaster. U.S. Pat. No. 3,008,273 discloses a hollow preformed arch and method of making the same comprising plasterboard panels and metal comer beads having a plurality of slits for gripping cement. The method generally comprises forming a curved panel by making a plurality of parallel kerf cuts therein, placing the panel over an arcuate form and applying plaster in the kerf cuts. U.S. Pat. No. 4,301,632 discloses a prefabricated full archway module having a pair of parallel upright panels extending between the floor and ceiling with internal braces and modules defining the upper portion of an archway. U.S. Pat. No. 4,400,917 discloses a unitary structure for a full arch-shaped passageway, which is adapted for drywall construction. The unitary structure includes a front panel, a rear panel and an arcuate panel portion therebetween. U.S. Pat. No. 4,601,138 discloses a prefabricated unitary body forming an archway including a comer bead and a recess therefor. U.S. Pat. No. 5,572,834 discloses a prefabricated arch form for use in constructing an archway wherein opposing sheet metal cheek are spaced apart by a curved throat to permit the cheeks to reside between the adjacent wall support and drywall and to fasten drywall. The foregoing art fails to disclose a prefabricated plaster arch or a mold, kit and/or method for making a prefabricated plaster arch as contemplated by the instant invention. 
     As the above noted art fails to provide a device or method that fills the foregoing gap in the prior art, there exists a need for a prefabricated plaster arch and mold, kit and method for making the same. The instant invention solves this problem by providing a prefabricated plaster arch that is installation ready, and a mold or kit and method for making plaster arches. 
     BRIEF SUMMARY OF THE INVENTION 
     Based on the foregoing, it is a primary object of the instant invention to provide a prefabricated plaster arch or semi-arch that is installation ready. 
     It is an additional object of the instant invention to provide a prefabricated plaster arch or semi-arch that is easy to install and inexpensive. 
     It is another object of the instant invention to provide a prefabricated plaster arch or semi-arch that can be installed with common fasteners and only requires that the gap between the arch and wall be covered. 
     It is also an object of the instant invention to provide a mold that facilitates the making of plaster arches or semi-arches. 
     It is a further object of the instant invention to provide a method for making plaster arches or semi-arches. 
     In light of these and other objects, the instant invention comprises a prefabricated plaster arch or semi-arch ready for installation in the corner of a passageway, and a mold, kit and method for making a plaster arch. The plaster arch generally comprises two substantially perpendicular leg portions that meet at a common end, a concave arcuate surface between the two free ends of the leg portions and securing tabs extending outward from each leg. The leg portions form a right angle so that the arch fits within the comer of an opening, passageway or any wall and upper horizontal surface, such as a ceiling. The securing tabs are adaptable for securely receiving and/or passing conventional fasteners, such as screws, nails and anchors, that attach the tabs, and hence the arch, to the horizontal ceiling-like surface and vertical wall-like surface forming the opening. A full arch is formed by placing a prefabricated arch in opposing corners. The width of the arch corresponds to the width of the wall, but can vary. The length of the legs can vary to accommodate the desired look of the arch or arches and can be based on the size of the mold. The plaster arch can also include arcuate corner beads set in the plaster. The arcuate corner beads have slits at predetermined distances, such as an inch, to facilitate easy bending and shaping. The securing tabs may be defined by and project out from a securing clamp that provides a surface for the fill to adhere or grip to. The securing clamp is set in the fill and also includes a plaster retaining surface, locking tabs and/or additional reinforcement members extending therefrom plaster to improve the structural integrity of the arch and to prevent removal of the securing clamps and tabs. 
     The invention also comprises a mold, kit and method for making pre-fabricated doorway arches. The mold generally comprises a main mold body formed by a box-like structure having a bottom panel, at least two substantially perpendicular and removable side panels and one concave and arcuate panel bridging the side panels and defining a chamber therebetween and therein for filling with plaster or plaster-like material. The mold may also include a second set of substantially perpendicular and removable side panels opposing the first set of side panels and a second concave and arcuate panel joining the second set of side panels. The second set of side panels and second arcuate panel define a chamber therebetween and therein such that the mold forms a second arch when the second chamber is filled with plaster or a plaster-like material. The mold of the instant invention can therefore form up to two substantially uniform plaster arches by setting the securing tabs in the voids and filling the chambers with plaster, paste, concrete, stucco, liquid plastic, joint compound or other suitable filler. The side panels are preferably removable from the main body to facilitate convenient removal of the arches once they have set. The side panels may slide within tracks formed in the bottom panel. The mold body also makes it convenient to uniformly and evenly remove excess filler from the chamber(s) with a trowel blade and to set an arcuate corner bead in the fill. 
     The kit of the invention includes the mold main body, at least two securing tabs and a filler mix for filling the chamber(s). The kit may further include at least one pair of corner beads having slits cut therein for facilitating easy shaping. The main body comprises at least one set of side panels and at least one arcuate panel, but preferably includes two sets of side panels and two arcuate panels. The side panels are preferably removable. The main body may also include a removable top for accessing the chamber(s) when filling and covering the chamber(s) when the fill is setting and curing. The mold and kit may also include a retaining strap for holding the side panels in place. 
     The method of making prefabricated plaster arches generally comprise setting up the mold, filling at least one chamber in the mold with a suitable fill, leveling the fill, allowing the fill to set, removing the side panels and removing the arch or arches from the mold. The mold is set up by securely installing or mounting the side panels, setting the arcuate panels if not already fixed to the bottom panel, and setting and orienting the securing clamps in the chambers adjacent the side panels. The arches are then made by filling the chamber or chambers with a suitable fill, leveling the fill with a trowel or other suitable instrument, allowing the fill to set and cure, removing the side panels and removing the arch or arches once the fill has set or cured. The method may also include securing a strap around the outside of the mold to secure the side panels and/or placing a first corner bead along the bottom of the arcuate panel before filling and placing a second comer bead along the top of the arcuate panel after filling the chamber or chambers. The method of the invention may further include installation of at least one arch or two arches, which comprises the steps of aligning the plaster arch in the desired corner of the desired opening, passing or forcing at least one fastener through each securing tab into the corresponding wall surface behind the securing tab, filling or concealing the seams between the arch and wall/ceiling surface with a joint compound, sanding or texturing the surface smooth and painting the arch. 
     In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 a  is a front perspective view of the preferred embodiment of the prefabricated plaster arches of the instant invention installed in a passageway. 
     FIG. 1 b  is a front elevational full cut-away view of the preferred embodiment of the prefabricated plaster arches of the instant invention as installed in a passageway to make a semi-arch. 
     FIG. 1 c  is a front elevational view of the preferred embodiment of the prefabricated plaster arches of the instant invention showing two arches installed in a passageway to make a full arch. 
     FIG. 2 is a front elevational view of the preferred embodiment of the prefabricated plaster arches of the instant invention showing the securing clamp in phantom. 
     FIG. 3 is a perspective view of the preferred embodiment of the prefabricated plaster arches of the instant invention. 
     FIG. 4 is an end elevational view of the preferred embodiment of the prefabricated plaster arches of the instant invention. 
     FIG. 5 is a side elevational view of the securing clamp used in the preferred embodiment of the prefabricated plaster arches of the instant invention. 
     FIG. 6 is a perspective view of the preferred securing clamp used in the preferred embodiment of the prefabricated plaster arches of the instant invention. 
     FIG. 7 is a perspective view of an alternative securing clamp used in the preferred embodiment of the prefabricated plaster arches of the instant invention. 
     FIG. 8 is a plan view of the preferred embodiment of the mold and kit of the instant invention used in simultaneously making two prefabricated plaster arches in accordance with the instant invention. 
     FIG. 9 is a plan view of the preferred embodiment of the mold and kit of the instant invention used in making one prefabricated plaster arch in accordance with the instant invention. 
     FIG. 10 is a perspective view of the preferred embodiment of the mold and kit of the instant invention showing one chamber filled and another chamber empty. 
     FIG. 11 is a perspective view of the preferred embodiment of the mold and kit of the instant invention, with the side panels shown removed, illustrating two prefabricated plaster arches before removal from the mold as made in accordance with the instant invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the drawings, FIGS. 1 a - 11  depict the preferred and alternative embodiments of the prefabricated plaster arches and mold of the instant invention, which are generally characterized by reference numerals  10  and  50  respectively. Referring to FIGS. 1 a - 1   c , the instant invention comprises a prefabricated plaster arch  10  that fits in the corner of an opening or passageway  1  and may also be classified as a quarter arch. With reference to FIGS. 1 a - 4 , the prefabricated plaster arch  10  comprises a first leg portion  12 , a second leg portion  14 , a concave arcuate surface  16  and securing tabs  18 . The prefabricated arch  10  is preferably made from a plaster fill  30  or plaster-like material, paste, concrete, stucco, liquid plastic, joint compound or other suitable filler. The first and second leg portions  12 ,  14  meet at a common end in a substantially perpendicular orientation. The concave arcuate surface  18  joins the two free ends of the leg portions  12 ,  14 . The width of the arch  10  corresponds to the width of the corresponding wall, which typically vary between 2.5 inches and 5.0 inches. The length of the leg portions  12 ,  14  can also vary to accommodate the desired look of the archway. For instance, the top leg portions  12  can comprise half the width of an opening  1  such that the securement of a prefabricated arch  10  in opposing corners creates a full archway, as shown in FIG. 1 c . Conversely, the top leg portions  12  may comprise a length that is less than half the width of an opening  1 , so as to form only two opposing quarter arches, as shown in FIG. 1 c . A securing tab  18  projects outward from each leg portion  12 ,  14  and is adaptable for receiving fastening hardware, such as screws, nails, anchors and/or other known fasteners, to secure the arch  10  to a wall and/or ceiling surface, as shown in FIGS. 1 a  and  1   b . The securing tabs  18  may define securing apertures  19 , as shown in FIGS. 3 and 4. 
     With reference to FIGS. 5-7, the securing tab  18  is preferably defined by a securing clamp  17 , which resides in the body of the prefabricated arch. The securing clamp  17  comprises a securing tab  18 , fastening apertures  19 , at least one plaster retaining projection  20 , at least one locking tab  22  and locking tab apertures  26 . Referring to FIGS. 5 and 6, the plaster retainer projection  20  projects upward from a base section and comprises an arcuate top edge having a radius of curvature corresponding to the arcuate surface  18  of the arcuate molding surface  56  and hence the prefabricated arch. The locking tab  22  preferably comprises at least one upward projecting plate having a plurality of apertures for reinforcing the plaster or plaster-like fill making up the arch  10 . n an alternative embodiment, the securing clamp  17 ′ may comprise at least two plaster retaining projections  20 ′ and at least two locking tabs  22 ′ extending upward from the base section along and proximal to opposing edges, as shown in FIG.  7 . The alternative retaining projections also define top arcuate edges having radii of curvature corresponding to the arcuate molding surface  56  and the arcuate surface defined by the arch  10 . The securing clamps  17 ,  17 ′ provide reinforcement for the plaster  30  or plaster-like fill to strengthen the structural integrity of the arches  10 , prevent removal of the clamps  17 ,  17 ′ and tabs  18 ,  18 ′ from the arches  10  and provide a surface for securing the arches  10  to a wall and/or ceiling. The securing tabs  18 ,  18 ′ may include fastening apertures  19 ,  19 ′ for passing hardware requiring an aperture. 
     With reference to FIGS. 8 and 9, the invention also comprises a mold  50 , kit and method for making pre-fabricated doorway arches. Referring to FIG. 9, the mold  50  generally comprises a main mold body formed by a box-like structure having a bottom panel  52 , at least two substantially perpendicular and removable side panels  54  and at least one concave and arcuate panel  56  bridging the side panels  54 . The side panels  54 , bottom panel  52  and arcuate panel  56  define a chamber  59  therebetween and therein for filling with plaster  30  or plaster-like material for making at least one arch  10 . The base  52  defines at least one track or channel  53  for slidably receiving each side panel  54 . The mold  50  may also provide at least one securing clamp  17  or securing tab  18 . The arcuate molding surface may be defined by an arch forming boss  55  projecting upward from the bottom panel  52 . The arch forming boss  55  comprises one arcuate molding surface  56  for making one arch  10  and two arcuate molding surfaces  56  for making two arches  10 . The arcuate molding surface  56  may include a molding stile or plate  60  for separating and providing for convenient separation of the molded arch  10  from the mold  50 . A comer bead  28  may be placed in the bottom of the chamber  59  along the arcuate molding surface  56  before pouring in the fill. Thereafter, a corner bead  28  may be placed at the top of the chamber  59  along the arcuate molding. The corner beads  28  provide structural integrity along the edges of the arches  10 . Prior to filling the chamber with the required fill, as disclosed herein, the securing clamp(s)  17  or  17 ′ should be positioned in the chamber  59  adjacent the side panels  54 . 
     With reference to FIG. 8, the mold  50  may comprise structure for forming and making at least two arches  10  in another embodiment. In this embodiment, the mold generally includes two sets of substantially perpendicular and removable side panels  54  and two arcuate molding panels or surfaces  56 . Two sets of comer beads  28  and securing clamps  17  and/or tabs  18  may also be provided with the mold and/or kit. The bottom panel  52  defines and/or provides a track or channel  53  for each side panel  54 . The two sets of side panels  54  comprise four slidably removable panels, wherein the first and second sets are in opposing positions. The two concave and arcuate panels/surfaces  56  are preferably defined along opposite surfaces of the boss  55  and engage the first and second sets of side panels  54 . The two sets of side panels  54 , arcuate panels  56  and bottom panel  52  define two independent chambers  59  therebetween and therein for filling with plaster  30  or a plaster-like material to make at least two arches  10 . A cover or top may be provided to conceal the fill while it sets and cures. The side panels  54  may each include a notch  17  for slidably receiving the end of a side panel  54  to effectuate a substantially modular fit that stabilizes the side panels  54  during the filling, setting and curing steps. The side panels  54  may be further stabilized with a removable and adjustable strap that may be tightened and loosened. 
     The process of making arches  10  in accordance with the invention generally comprises securely setting the side panels  54  on the bottom panel  52 , installing or inserting a securing clamp  17  or securing panel  18  in each chamber  59 , filling each chamber with a predetermined filler, such as plaster, concrete or other filler provided for herein, leveling and floating the poured fill, allowing the fill to set, removing the side panels after the fill has fully cured, and/or removing the arch or arches  10 . The method of the invention may also include placing a comer bead  28  in each chamber adjacent the arcuate molding surface  56 , tightly securing a strap around the outer peripheral surfaces of the mold  50  and/or leveling the fill with a trowel or other instrument to remove excess fill spilling over or rising above the side panels&#39;  54  top edges and the top surface of the arch forming boss  55 . The side panels  54  are slidable set or placed within the tracks  53  defined by the bottom panel  52 . A securing clamp  17  or tab  18  is placed in each chamber  59  so that the plaster retaining projection(s)  20  and locking tab(s)  22  are substantially parallel with the bottom panel and the securing tabs  18  project outward from the chamber(s)  59 . The chambers  59  are preferably filled with a plaster  30 , but may also be filled with a paste, concrete, stucco, liquid plastic, joint compound or other suitable filler. Once the fill  30  is completely set and cured, the strap is removed (if one was used), the side panels  54  are removed from the main body and the arches  10  removed. The side panels may slide within tracks formed in the bottom panel. The mold body also makes it convenient to uniformly and evenly remove excess filler from the chamber(s) with a trowel blade and to set an arcuate corner bead  28  in the fill. The kit of the invention includes the mold  50  with at least one chamber  59 , at least one securing clamp  17 ,  17 ′ and/or tab  18 ,  18 ′ and a filler mix  30  for filling the chamber(s). The kit may further include at least one pair of corner beads  28  having slits cut therein for facilitating easy shaping and a retaining strap. 
     The method of the invention may further include installation of at least one arch  10  or two arches  10 , which comprises the steps of aligning the plaster arch  10  in the desired comer of the desired opening, passing or forcing at least one fastener through each securing tab  18 ,  18 ′ into the corresponding wall surface behind the securing tab  18 ,  18 ′, filling or concealing the seams between the arch and wall/ceiling surface with a joint compound, sanding or texturing the surface smooth and painting the arch. 
     The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious structural and/or functional modifications will occur to a person skilled in the art.