Information
-
Patent Grant
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6240698
-
Patent Number
6,240,698
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Date Filed
Tuesday, January 25, 200025 years ago
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Date Issued
Tuesday, June 5, 200123 years ago
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Inventors
-
-
Examiners
- Stephan; Beth A.
- Chavez; Pat J.
Agents
- Fulwider Patton Lee & Utecht, LLP
-
CPC
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US Classifications
Field of Search
US
- 052 30915
- 052 7363
- 052 7202
- 249 143
- 425 84
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International Classifications
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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)