Composite baluster

Information

  • Patent Grant
  • 6240698
  • Patent Number
    6,240,698
  • Date Filed
    Tuesday, January 25, 2000
    25 years ago
  • Date Issued
    Tuesday, June 5, 2001
    23 years ago
  • Inventors
  • Examiners
    • Stephan; Beth A.
    • Chavez; Pat J.
    Agents
    • Fulwider Patton Lee & Utecht, LLP
Abstract
A composite baluster includes an elongated core made of wood, and a plastic outer shell molded over and enclosing the core. A bottom end of the core projects outward and downward from a bottom end of the outer shell. A wooden end piece is connected to and covers the bottom ends of the core and outer shell. The end piece has a top end face recessed to form a cavity for receiving the bottom end of the core. The top end face of the end piece abuts against the bottom end of the outer shell.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The invention relates to the construction of a baluster, more particularly to the construction of a composite baluster.




2. Description of the Related Art




Conventional wooden staircase balusters are generally formed as a rod which is provided with a pleasing outline for aesthetic purposes. As shown in

FIG. 1

, a typical wooden baluster


1


includes an upper tapered section


101


, a neck


102


, a lower section


103


of rectangular cross-section, and a tenon


104


formed at a bottom end of the lower section


103


. In setting up the baluster


1


, the top end of the upper tapered section


101


is embedded into a top stair-rail, and the tenon


104


is fitted in a hole in the floor of a staircase and is nailed securely thereat.




However, the known wooden baluster


1


has the following disadvantages:




1. A considerable amount of wood is consumed in manufacturing the wooden baluster


1


, and a lot of waste is produced during the processing of wood.




2. As wood is not sufficiently strong, the wooden baluster


1


is susceptible to damage upon impact and is prone to crack and deform when subjected to varying weather.




3. Although the upper tapered section


101


and the neck section


102


of the wooden baluster


1


may be machined via a lathe machine, the lower section


103


must be formed by using a planing machine. Therefore, different processing operations have to be performed to finish the entire profile of the wooden baluster


1


, thus increasing the complexity of the manufacturing process.




SUMMARY OF THE INVENTION




An object of the present invention is to provide a composite baluster which has a strong construction and which can be produced via a simplified process.




According to the present invention, a composite baluster includes an elongated core made of wood and having a bottom end, and a plastic outer shell molded over and enclosing the core. The bottom end of the core projects outward and downward from a bottom end of the outer shell. A wooden end piece is connected to and covers the bottom ends of the core and outer shell. The end piece has a top end face recessed to form a cavity for receiving the bottom end of the core. The top end face abuts against the bottom end of the outer shell.











BRIEF DESCRIPTION OF THE DRAWINGS




Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:





FIG. 1

is a sectional view of a conventional baluster;





FIG. 2

is a perspective view of a composite baluster embodying the present invention;





FIG. 3

is a sectional view of the composite baluster of

FIG. 2

; and





FIG. 4

is a sectional view showing another embodiment of the composite baluster according to the present invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring to

FIGS. 2 and 3

, a composite baluster


100


embodying the present invention is shown to include a wooden core


10


, a plastic outer shell


20


, and a wooden end piece


30


.




The core


10


is formed as a rod by a wood-forming process and may be made from timber or plywood. The cross-section of the core


10


may be circular and polygonal.




The plastic outer shell


20


is made from an unsaturated resin and a curing agent and is molded over the core


10


. The outer shell


20


includes an upwardly tapered upper section


110


, a neck section


120


below said upper section


110


, and a lower section


130


of rectangular cross-section below the neck section


120


. The plastic outer shell


20


has an outer cross-section which is gradually increased downward from a top end of the upper section


110


and which is reduced from the upper section


110


to the neck section


120


and is then increased from the neck section


120


to the lower section


130


. A bottom end


11


of the core


10


projects outward and downward from a bottom end


21


of the lower section


130


.




The end piece


30


is made of wood and has a bottom end


31


formed with a tenon


140


of substantially circular cross-section, and a top end face


311


which is recessed to form a cavity


32


for receiving snugly the exposed bottom end


11


of the core


10


. When the end piece


30


is pressed against the bottom end


11


of the core


10


and the bottom end


21


of the lower section


130


, the bottom end


11


of the core


10


is fitted in the cavity


32


, and the top end face


311


of the end piece


30


abuts against the bottom end


21


of the lower section


130


.




With the aforesaid construction, the composite baluster


100


not only possesses the toughness and flexibility of wood but also exhibits high strength and nondeformable characteristics of the unsaturated resin. In addition, the baluster


100


provides resistance to weather and cracking. As the end piece


30


is made of wood, it can be nailed on a floor without producing cracks.




The composite baluster


100


can be fabricated as follows: Firstly, the core


10


is formed as a straight rod by a wood-working process. Then, the core


10


is placed in a mold with a mold cavity (not shown) having a shape conforming to that of the outer shell


20


. The mold is vertically arranged with a portion corresponding to the lower section


130


being disposed upward and with another portion corresponding to the upper section


110


being disposed downward. An unsaturated resin containing a curing agent is poured into the mold cavity from the top of the mold. A portion of the core


10


is left exposed from the resin adjacent to the top of the mold. After the resin is cured, the mold is removed. The end piece


30


is attached to the core


10


and the outer shell


20


by receiving the exposed portion of the core


10


in the cavity


32


of the end piece


30


and by bonding adhesively the exposed portion to the end piece


30


. After painting the outer shell


20


and the end piece


30


, the fabrication of the baluster


100


is completed.




The composite baluster


100


provides the advantage of reducing the consumption of wood and avoiding the wasting of wooden material. Due to the presence of the plastic outer shell


20


, the composite baluster


100


possesses a strong construction which can prevent damage and deformation upon impact and which provides resistance to cracking and deformation due to varying weather. The wooden core


10


of the composite baluster


10


provides a measure of toughness and flexibility. Moreover, as the outline of the composite baluster


100


is formed via a molding process, the need to perform different wood-working operations, which are required in the processing of the conventional wooden baluster, can be eliminated. The manufacturing process of the composite baluster


100


is thus simple as compared to that of the conventional wooden baluster.




Another embodiment of the composite baluster according to the present invention is shown at


100


′ in FIG.


4


. The composite baluster


100


′ differs from the composite baluster


100


of the previous embodiment in that the end piece


140


′ has no tenon at its bottom end and that the bottom end


11


of the core


10


and the end piece


140


′ are bored to form aligned holes


111


and


141


so that the composite baluster


100


′ can be screwed to a floor via a locking screw (not shown) which will be inserted into the holes


11


and


141


through the floor.




While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.



Claims
  • 1. A composite baluster comprising:an elongated core made of wood and having a bottom end; and a plastic outer shell molded over and enclosing said core, said bottom end of said core projecting outward and downward from a bottom end of said outer shell; and a wooden end piece connected to and covering said bottom ends of said core and outer shell, said end piece having a top end face recessed to form a cavity for receiving said bottom end of said core, said top end face abutting against said bottom end of said outer shell.
  • 2. The composite baluster as claimed in claim 1, wherein said plastic outer shell includes an upwardly tapered upper section, a neck section below said tapered upper section, and a lower section below said neck section, said outer shell having an outer cross-section which is gradually increased downward from a top end of said upper section and which is reduced from said upper section to said neck section and is then increased from said neck section to said lower section.
  • 3. The composite baluster as claimed in claim 1, wherein said end piece is bonded adhesively to said bottom ends of said core and outer shell.
  • 4. The composite baluster as claimed in claim 1, wherein said end piece further has a downwardly projecting tenon formed at a bottom end of said end piece.
  • 5. The composite baluster as claimed in claim 1, wherein said bottom end of said core and said end piece are bored to form therein aligned holes which are adapted to receive a locking screw.
US Referenced Citations (4)
Number Name Date Kind
4035978 Bajorek et al. Jul 1977
5035401 Solter Jul 1991
5568709 Steckler Oct 1996
5626331 Erwin May 1997