U.S. patent application number 09/735390 was filed with the patent office on 2001-05-10 for heating method and assembly for staircase.
Invention is credited to Birch, Larry L., Eve, John S..
Application Number | 20010000841 09/735390 |
Document ID | / |
Family ID | 26977933 |
Filed Date | 2001-05-10 |
United States Patent
Application |
20010000841 |
Kind Code |
A1 |
Birch, Larry L. ; et
al. |
May 10, 2001 |
Heating method and assembly for staircase
Abstract
A heating assembly is provided which includes a metal stair
tread member having an upper horizontal surface and a bottom
surface for mounting on a stair tread of a staircase. A strip
heating element is attached to the bottom surface of the stair
tread member. A first covering of synthetic material encapsulates
the horizontal surface of the metal stair tread member and the
strip heating element on bottom surface of the stair tread member.
The strip heating element is contiguous with the bottom surface and
is attached thereto by a gasket extending around the peripheral
edge of the strip heating element. A thermostat is electrically
connected to the strip heater and to a power source for selectively
supplying electric current to the strip heater in response to
changes ambient temperatures. A temperature sensing element is in
electrical communication with the thermostat wherein the thermostat
selectively supplies the current to the strip heating element. The
thermostat has multiple settings which are manually selected for
providing different selected current levels to the strip heater in
response to temperature changes at preselected ambient temperature
levels.
Inventors: |
Birch, Larry L.; (Highlands
Ranch, CO) ; Eve, John S.; (Highlands Ranch,
CO) |
Correspondence
Address: |
Fields & Johnson, P.C.
8480 East Orchard, Suite 5600
Englewood
CO
80111
US
|
Family ID: |
26977933 |
Appl. No.: |
09/735390 |
Filed: |
December 11, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09735390 |
Dec 11, 2000 |
|
|
|
09311526 |
May 13, 1999 |
|
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|
Current U.S.
Class: |
52/182 ;
52/188 |
Current CPC
Class: |
E04F 11/00 20130101;
E04F 11/112 20130101; E04F 11/16 20130101 |
Class at
Publication: |
52/182 ;
52/188 |
International
Class: |
E04F 011/00; E04F
019/10 |
Claims
What is claimed is:
1. A heating assembly for a staircase having a plurality of stair
treads, said heating assembly comprising: a metal stair tread
member, having an upper horizontal surface and a bottom surface,
for mounting on a stair tread of the staircase; a strip heater
element, having a peripheral edge, attached to and in contiguous
contact with said bottom surface of said stair tread member; and a
first covering of synthetic material placed on at least said
horizontal upper surface and over said strip heater element on said
bottom surface of said stair tread member.
2. A heating assembly, as claimed in claim 1, further including: a
dispersed layer of particles placed on said first covering at said
upper surface; and a second covering of synthetic material placed
on said dispersed layer of particles encapsulating said dispersed
layer of particles between said first and second coverings to form
a wear surface.
3. A heating assembly, as claimed in claim 1, further including: a
gasket extending around said peripheral edge of said strip heating
element attaching said strip heating element to said bottom surface
of said stair tread member.
4. A heating assembly, as claimed in claim 1, further including: a
thermostat electrically connected to said strip heater and
connectable to a power source for selectively supply electric
current to said strip heater in response to changes in ambient
temperature.
5. A heating assembly, as claimed in claim 4, further including: a
temperature sensing element in electrical communication with said
thermostat wherein said thermostat selectively supplies the current
to said strip heating element.
6. A heating assembly, as claim in claim 5, wherein: said
thermostat has multiple settings which are manually selected for
providing different selected current levels to said strip heater in
response to temperature changes at preselected ambient temperature
levels.
7. A method of melting ice and snow off of a stair tread of a
staircase, said method comprising the steps of: providing a metal
stair tread member which is substantially coextensive with the
stair tread, the stair tread member having an upper surface and a
bottom surface; attaching a strip heater to the bottom surface of
the stair tread member so that the strip heater is in surface
contact with the bottom surface; encapsulating the stair tread
member and the strip heater in a first covering of synthetic
material to form a heating assembly; electrically connecting the
strip heater to a source of current; and supplying current to the
strip heater in response to a predetermined ambient
temperature.
8. A method, as claimed in claim 7, wherein after the encapsulating
step: dispersing a layer of particles on the first covering at the
upper surface; placing a second layer of synthetic material on the
dispersed layer of particles to encapsulate the dispersed layer of
particles between the first and second coverings to form a wear
surface.
9. A method, as claimed in claim 7, including the further step of:
attaching the strip heater by means of a peripheral gasket
extending therearound so that the strip heater is in contact with
the bottom surface of the stair tread member.
10. A method, as claimed in claim 7, wherein said step of supplying
current includes: electrically connecting a thermostat to the strip
heater and to a source of current; and sensing the ambient
temperature with a temperature sensing element in electrical
communication with the thermostat wherein the thermostat
selectively supplies the current to the strip heater based on
sensed ambient temperature.
11. A method, as claimed in claim 10, including the further step
of: using the thermostat to manually select different current
levels to the provided to the strip heater in response to
temperature changes at preselected ambient temperature levels.
Description
TECHNICAL FIELD
1. The present invention relates to a staircase and a staircase
repair device adapted to be used for both residential and
commercial buildings and, more particularly, to a staircase
including specially constructed stair tread members for use with
standard stringers, and a staircase repair device or kit which can
refurbish an existing staircase in need of repair without
modification of the original staircase. A heating assembly also is
provided for melting ice and snow off of stair treads of a
staircase. Methods are also provided for fabrication.
BACKGROUND ART
2. A number of prior art devices exist which relate to the
construction of a staircase, or the repair or refurbishing of a
staircase. Particularly for conventional outside stairs and
emergency stairs in both residential and commercial applications,
such stairs are often constructed of materials which do not
withstand heavy traffic or harsh environmental conditions. Because
of safety concerns, stairs should always be kept in a high state of
maintenance. However, the cost to repair damaged staircases can be
quite prohibitive, even for minor flaws. For example, stairs formed
of concrete which have chips or other surface defects are not only
dangerous, but are also unsightly. Concrete repair is usually a
very temporary measure and, particularly in high traffic areas, the
concrete repair is never as wear-resistant as the original
concrete. For wooden stairs, the wood has a tendency to warp or
deform along heavy traffic areas. Even if constructed of treated
lumber, the wood becomes unsightly over time.
3. There are a number of examples of prior art devices which have
attempted to overcome one or more of the following problems. These
devices can be in the form of either a repair unit, or a complete
staircase construction.
4. U.S. Pat. No. 5,357,724 discloses a stair tread in which rubber
sheet material is placed around a metal core section, and then
heated to melt the sheets together. Once heated, the core section
is encapsulated within the rubber. The stair tread has anti-slip
serrations formed on its upper surface. A front face or overhanging
front lip forms the front edge of the stair tread, and a vertically
extending rear flange forms the rear face or edge of the stair
tread. The upper edge of the rear face has a groove to accept the
lower edge of a riser board, while the upper edge of the riser
board is inserted into a corresponding groove formed in the lower
edge of the front face of the next higher stair tread.
5. U.S. Pat. No. 5,799,448 discloses an adjustable closed riser
metal staircase system. The system includes a plurality of stair
treads which may be assembled into staircases having different rise
heights. The stair treads include a vertical riser portion and a
horizontal walking surface, preferably made of a slip-resistant
material such as Mebac.TM., a coating of thermally sprayed steel
encapsulating a dispersion of grit materials, normally aluminum
oxide. The nose piece portion of the stair tread is formed at the
front of the stair by bending the forward edge of the steel plate
downward. When assembled, the upper end of the riser portion is
inserted within a channel created by the bent nosepiece of the next
higher stair tread assembly.
6. U.S. Pat. No. 4,783,939 discloses a composite covering for
improving worn-out treadways of steps. This covering includes a
stair tread section which is placed over the existing stair tread,
and an integral vertical flange which overhangs the front lip of
the stair tread section. The covering is constructed of a
scuff-resistant plastic. The underside of the stair tread section
includes an insert of pressboard, and a binder which helps raise
the elevation of worn out sections or indentations, and also serves
to bind the layers of the composite covering.
7. U.S. Pat. No. 5,660,009 discloses a metal stairway construction
in which stair steps are supported between a pair of trimmed sheet
metal stringer panels on each side of the stairway. Each step of
the stairway is formed of metal treads and risers cut to
appropriate lengths from conventional joice members provided on
site. The metal treads and risers are attached at opposite ends
thereof to respective stringer panels by way of standard angle
brackets. Threaded self-drilling fasteners attach each angle
bracket to a corresponding stringer panel and to an associated
metal tread or metal riser. Wooden treads and risers are attached
over the corresponding metal treads and risers by standard
self-drilling screws.
8. While the foregoing references may be adequate for their
intended purposes, there are certain advantages with the present
invention which are not found in these references. One advantage is
that the staircase repair device of this invention can be used with
any type of existing staircase, whether it be concrete, wood, or
metal. Another advantage is that this staircase repair device can
be used to repair a staircase without preparation or modification
of the original staircase wear surfaces. Yet another advantage not
overcome by the prior art is the use of a staircase repair device
which has high strength and weathering capabilities, yet does not
detract from the general aesthetic appearance of the staircase. The
same advantages discussed above also apply to the staircase of this
invention. Additionally, the staircase of this invention is simple
in design, and can be used for stairways in a wide array of
residential and commercial buildings.
9. Removal of ice and snow from the stair tread of a staircase is a
chronic problem during cold winter weather. Typically, ice and snow
are removed by scraping them from the stair tread or applying a
chemical thereto which causes the ice and snow to melt. Heating
devices are sometimes provided under surfaces such as driveways and
sidewalks to melt snow. However, they are quite expensive and not
practical for many stairways.
DISCLOSURE OF THE INVENTION
10. In accordance with this invention, a staircase and a staircase
repair device or kit are provided. The staircase repair device or
kit forms a first embodiment and is comprised of two major
components, namely, a stair tread repair member and a riser repair
member. Both of these members are constructed of metal, preferably
raw steel, bent to desired shapes. The stair tread repair member
includes a front flange and an inward protruding lip. Holes may be
drilled in the wearing surface of the stair tread repair member in
order to accept fasteners which help to secure the stair tread
repair member to an existing stair tread. The riser repair member
includes an outward protruding flange. Holes may also be drilled in
the riser repair member to accept fasteners for attachment of the
riser repair member to an existing staircase riser. Both the stair
tread and riser repair members are coated with a synthetic material
which protects the metal from corrosion and other environmental
hazards. The coating is preferably in the form of a polyurethane
which is sprayed in liquid form to encapsulate the members therein.
The upper wearing surface of the stair tread repair member also has
a slip-free surface. This slip-free surface is formed by particles
which are spread or sprinkled over the first sprayed coating of
synthetic material. These particles are spread on the first coating
while it is wet which allows the particles to become embedded in
the first coating. Then, a second coating of synthetic material is
sprayed over the embedded particles to seal the particles between
the first and second coatings. The particles may be materials such
as coal dust, aluminum oxide, walnut shells, and other known
granular-type material which is used to create slip-free surfaces.
It shall be understood that the stair tread repair member serves as
a subcombination which may be used to repair the stair treads of an
existing staircase.
11. In a second embodiment, the invention is a staircase which
includes a plurality of stair tread members which span between a
pair of spaced stringers. The stair tread member is similar to the
stair tread repair member of the first embodiment in that it is
also constructed of metal bent to a desired shape encapsulated
within a first coating of synthetic material, and having a
slip-free surface made of a particulate material sandwiched between
the first coating and a second applied coating. The stair tread
member further includes a pair of opposed side flanges disposed on
opposite ends of the stair tread member, and opposing front and
rear flanges. The stair tread member spans between a pair of common
stringers used in construction of staircases. The stair tread
member may be mounted to the facing inner surfaces of the
stringers, or may be mounted over the outer surfaces of the
stringers. Optionally, an L bracket or other similar supporting
hardware may be used to secure the stair tread member to the inner
surfaces of the stringers.
12. The second embodiment may be used in conjunction with either
metal or wood stringers. Holes are drilled in the side flanges for
receiving fasteners which secure the stair tread member to the
stringers. If desired, a riser member could also be used with the
invention of the second embodiment. More specifically, a riser
similar to the riser repair member of the first embodiment could be
used in the second embodiment. The riser in the second embodiment
could simply be rectangular in shape and coated in the same way as
the other components.
13. Methods of fabricating a stair tread repair member and of
fabricating a stair tread member in a new staircase are also
provided. Both methods involve the provision of a flat sheet of
metal cut to a desired size. The metal sheet is sanded to roughen
its surfaces in preparation for coating with a synthetic material.
A primer may be applied to further prepare the metal sheet for
coating. The metal sheet is bent by a metal brake machine to the
desired shape. In fabrication of the stair tread repair member, the
sheet is bent to form the front flange and inward protruding lip.
For the stair tread member of a new staircase, the sheet is bent to
include front and rear flanges, and the opposed side flanges. In
order to bend the sheet of metal used in the stair tread member,
corner sections are removed. After the sheet has been bent, the
joints formed at the corners of the stair tread members may be
welded together. Prior to or after bending, screw holes are punched
or drilled in the metal sheets enabling fasteners to be received
therethrough.
14. Once the stair tread repair member and the stair tread member
have been bent to the desired shapes, they may be sprayed with a
synthetic coating, preferably polyurethane. This polyurethane is
applied to all exposed surfaces. The encapsulation of the members
within the coating helps to ensure that all surfaces are protected
from corrosion and other environmental hazards. The upper wearing
surfaces of the members are then sprinkled with a dispersed layer
of particles. This preferably occurs when the first applied coating
is still wet which enables the particles to become embedded within
the first coating. A second coating of polyurethane is then applied
over the dispersed layer of particles to encapsulate the particles
between the first and second coatings. A slip-free surface is
therefore formed by the second coating covering the particles. In
addition to providing weather-resistant surfaces, the coatings of
polyurethane also help to dampen noise normally associated with
metal stair treads, and help to keep the wearing surfaces
scuff-free. Additionally, the applied polyurethane may be mixed
with a desired color which enables the components to match or
complement existing colors on the building. For the staircase
embodiment, the stair tread members may include diagonal stress
lines pressed on the upper wearing surfaces. This pre-stressing of
the upper wearing surfaces adds strength to resist any buckling or
wobbling of the upper wearing surfaces.
15. The apparatuses and methods of this invention provide a
staircase repair device and a staircase which are extremely
durable, simple in construction, aesthetically pleasing, have
integral slip-free surfaces, and resist scuffing. Furthermore,
these devices are simple to install and are universal in their
ability to be used for all types of buildings.
16. This invention also contemplates a structure and method for
removing ice and snow from a stairway. A heating assembly is
provided which includes a metal stair tread member having an upper
horizontal surface and a bottom surface for mounting on a stair
tread of a staircase. A strip heating element is attached to the
bottom surface of the stair tread member. Than a first covering of
synthetic material encapsulates the horizontal surface of the metal
stair tread member and the strip heating element on bottom surface
of the stair tread member. The strip heating element is contiguous
with the bottom surface and is attached thereto by a gasket
extending around the peripheral edge of the strip heating element.
A thermostat is electrically connected to the strip heater and to a
power source for selectively supplying electric current to the
strip heater in response to changes ambient temperatures. A
temperature sensing element is in electrical communication with the
thermostat wherein the thermostat selectively supplies the current
to the strip heating element. The thermostat has multiple settings
which can be manually selected for providing different selected
current levels to the strip heater at preselected ambient
temperature levels.
17. Additional advantages of this invention will become apparent
from the description which follows, taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
18. FIG. 1 is a perspective view of a stair tread repair member of
the first embodiment;
19. FIG. 2 is a perspective view of a riser repair member of the
first embodiment;
20. FIG. 3 is a fragmentary perspective view of the staircase
repair device of the first embodiment mounted to an existing
staircase or stairway;
21. FIG. 4 is an enlarged vertical section, taken along line 4-4 of
FIG. 3 illustrating one manner in which the first embodiment may be
mounted to the existing staircase;
22. FIG. 5 is an enlarged vertical section taken along line 5-5 of
FIG. 3 illustrating further details on the mounting of the first
embodiment to the existing staircase;
23. FIG. 6 is an enlarged vertical section taken along line 6-6 of
FIG. 3 illustrating yet further details on the mounting of the
first embodiment to the existing staircase;
24. FIG. 7 is an enlarged fragmentary cross section of the stair
tread repair member in FIG. 3 which illustrates a core metal layer,
a first applied coating of synthetic material encapsulating the
core metal layer, a dispersed layer of particles applied on the
upper wearing surface, and a second coating placed on the dispersed
layer of particles and trapping them between the first and second
coatings;
25. FIG. 8 is a perspective view of a stair tread member of the
second embodiment;
26. FIG. 9 is a perspective view of the stair tread member of FIG.
8 prior to being bent into the desired shape;
27. FIG. 10 is a fragmentary perspective view of the staircase
construction of the second embodiment illustrating stair tread
repair members being mounted to stringers in three different
manners;
28. FIG. 11 is an enlarged fragmentary perspective view of FIG. 10
illustrating details of how a stair tread member is mounted over
the stringer;
29. FIG. 12 is an enlarged fragmentary vertical section taken along
line 12-12 of FIG. 10 illustrating details of how a stair tread
member may be mounted to the inner surfaces of the stringers;
30. FIG. 13 is another enlarged fragmentary vertical section taken
along line 13-13 of FIG. 10 illustrating another manner in which a
stair tread member may be mounted to the inner surfaces of the
stringers;
31. FIG. 14 is a fragmentary perspective view of a staircase
incorporating the heating assembly of this invention;
32. FIG. 15 A is an exploded view of the heating assembly of this
invention;
33. FIG. 15 B is an enlarged fragmentary section of a second
covering which encapsulate a layer of particles;
34. FIG. 15 C is an enlarged fragmentary section of a first
covering; and
35. FIG. 16 is an enlarged, fragmentary, horizontal section showing
details of the heating assembly construction.
BEST MODE FOR CARRYING OUT THE INVENTION
36. According to a first embodiment, a stair case repair device is
shown in FIGS. 1 and 2 which comprises a stair tread repair member
10 and a riser repair member 12. The stair tread repair member 10
has a wearing surface 14, and a front flange 16 extending from the
forward or front edge of the wearing surface 14. Contiguous with
the front flange 16 is an inward protruding lip 18. A plurality of
holes 19 may be drilled through the wearing surface 14 to receive
fasteners. The riser repair member in FIG. 2 has a riser surface 20
and an outwardly protruding flange 22. A plurality of holes 23 may
be drilled in both riser surface 20 and flange 22 to receive
fasteners.
37. FIG. 3 illustrates the staircase repair device installed on an
existing stairway or staircase. As shown, the existing stairway has
a plurality of stair treads 26 which are mounted between a pair of
stringers 24. A plurality of vertical risers 28 are also mounted
between the stringers 24. The top of the stairway leads to a
landing 30 which communicates with a doorway 32.
38. FIG. 4 illustrates in further detail the manner in which stair
tread repair members 10 and riser repair members 12 are secured to
the staircase. As shown, fasteners 38 may be placed through holes
19 and 23, respectively. Additionally, an appropriate industrial
adhesive or cement (not shown) may be used to secure members 10 and
12 to respective stair treads 26 and risers 28. FIG. 4 illustrates
wearing surface 14, front flange 16, and lip 18 closely conforming
to the lip 27 of the stair tread 26. However, it will understood
that front flange 16 and lip 18 function equally as well even if
there is some gap which exists between these members and the
exterior surfaces of lip 27. Also, the size and shape of front
flange 16 and lip 18 may be modified to fit the particular type of
staircase encountered. As further shown in FIG. 4, the upper edge
of riser surface 20 extends very nearly to or in contact with the
edge of lip 18. It should also be understood that riser repair
member 12 functions equally as well even if there is some gap
between lip 18 and riser surface 20.
39. As shown in FIG. 5, the edge of flange 22 is placed underneath
the rear edge of wearing surface 14. Fasteners 38 may also be used
to secure the members to each other and to stair tread 26 at this
location.
40. As shown in FIG. 6, the landing 30 may be repaired by the use
of landing repair member 39. Landing repair member 39 may also be
used to provide continuity with the covered stairway even if the
landing is not damaged. The landing repair member 39 may be secured
to the landing 30 by means of adhesive/cement, and/or by a
plurality of fasteners 38 extending through landing member 30 and
the edge of wearing surface 14.
41. FIG. 7 more specifically shows a cross section of materials
used to construct the stair tread repair member 10. A steel layer
40 is encapsulated within a first layer or coating of synthetic
material 42. Preferably, this coating is polyurethane which is
sprayed directly onto the steel layer 40. As shown, this layer
covers both the upper surface and the lower surface. A dispersed
layer of particles 44 is then sprinkled over the first layer 42. If
the first layer 42 is wet when the layer of particles 44 is
applied, the particles 44 will be embedded within the first layer
42 as shown. However, it will be understood that the dispersed
layer of particles 44 may be applied after the first layer 42 has
been allowed to dry. A second layer of polyurethane 46 is applied
over the dispersed layer of particles 44 trapping or encapsulating
them between the first and second layers Thus, the upper surface of
the stair tread repair member 10 has an undulating or rough surface
which is slip-free. The polyurethane used is extremely
wear-resistant and serves not only to protect the steel core, but
also to provide a bonding and sealing agent for the dispersed layer
of particles 44. The riser repair member 12 is also coated with a
layer of polyurethane; however, no slip-free surface is required so
no layer of particles or second layer of polyurethane is applied.
Landing repair member 39 may be made of the same composite
construction as stair tread repair member 10.
42. Although the first embodiment illustrates the use of both stair
tread repair members and riser repair members, it shall be
understood that the stair tread repair members alone can be used to
repair damaged staircases when such staircases have or do not have
risers. Since risers are not walking surfaces, a more
cost-effective repair can be completed without the use of the riser
repair members. Thus, the stair tread repair members serve as a
valuable subcombination of the first embodiment.
43. FIG. 10 illustrates the second embodiment of this invention
which is a stairway or staircase. This staircase includes two
primary members, namely, a plurality of stair tread members 50, and
a pair of opposed stringers 68. Beginning first with a discussion
of the stair tread members 50, one of which is shown in FIG. 8,
each includes a wearing surface 52, a front flange 54, a rear
flange 56, and a pair of opposed side flanges 58. A pair of
diagonally opposed stress lines 60 may be formed on the wearing
surface 52 to add bending strength. A plurality of holes 62 may be
drilled in side flanges 58 in order to receive fasteners, as
further discussed below.
44. FIG. 9 illustrates a stair tread member 50 prior to being bent
into shape. Corner sections 64 are removed which enable the sheet
of material to be bent along bend lines 66. Bending may be achieved
by a standard metal break machine. Preferably, holes 62 are drilled
prior to bending the member 50 into shape. Stress lines 60 are also
formed during the metal break operation. Thus, it is clear that
stair tread members 50 may be formed simply from rectangular sheets
of metal. After bending, corners 67 may secured as by welding, or
other well known means.
45. FIG. 10 illustrates the staircase assembled, and further shows
three ways in which stair tread members 50 may be mounted to the
pair of stringers 68. Stringers 68 may be of any well-known
construction to include cut pieces of lumber, or cut pieces of
heavy gauge metal. The stringers 68 each have inner surfaces 70,
outer surfaces 72, and upper surfaces defined by a plurality of
continuous rises 74 and runs 76. The details of how the most upper
stair tread member 50 attaches to the stringers 68 is shown in FIG.
11. In this case, the stair tread member 50 is mounted over the
outside surfaces 72 of stringers 68. Side flanges 58 are placed
over outer surfaces 72. In order to allow the stair tread member 50
to fit over runs 76, slots are cut out of the rear flange 56 near
the rear corners at least a width as wide as the width of run 76.
In FIG. 11, the width of the slot removed is shown as width 78. As
needed, fasteners 79 are then used to secure the stair tread member
50.
46. An alternate manner in which to mount a stair tread member 50
to the stringers 68 is through an inside mount. This is shown in
FIG. 12 wherein side flanges 58 are secured to the inner surfaces
70 of stringers 68. Fasteners 79 may also be used to secure the
connection. Thus, the method shown in FIG. 12 requires the stair
tread member 50 to be slightly shorter in length to accommodate the
smaller gap between the inner surfaces 70 of the opposed stringers
68.
47. FIG. 13 shows yet another manner in which the stair tread
members 50 may be secured to the stringers 68. As shown, this is
also an inside mount, but further includes the use of L-shaped
brackets 80 which help to stabilize the connection. As shown, L
brackets 80 are placed between side flanges 58 and inner surfaces
70. Fasteners 79 may also be used to secure the connection.
48. Although FIG. 10 does not illustrate the use of risers, it
shall be understood that risers can also be used. Riser repair
member 12 of the first embodiment may be modified to simply
eliminate flange 22, resulting in a rectangular shaped member. This
rectangular shaped member may be sized to fit the particular rise
74, and then secured thereto, either by fastener 79 or adhesive.
Stair tread members 50 are made of the same composite construction
shown in FIG. 7. If risers are used in this second embodiment, then
they can be coated in the same manner as the riser repair members
12 of the first embodiment.
49. Both the first and second embodiments illustrate staircases
with risers that include continuous rises and runs. However, it
shall be clearly understood that both the first and second
embodiments can be used with any type of stringers to include those
which do not have continuous rises and runs, but have continuous
flat upper surfaces. For these types of stringers, the stair tread
members of the second embodiment must utilize an inside mount.
50. In practice, it has been found that stair tread repair members
10 and stair tread members 50 can be made of 18 gauge metal which
provide adequate strength to resist undue deformation or bending.
It has also been found that riser repair members 12 may be made of
a thinner gauge steel, such as 24 gauge. In heavy traffic areas, it
has also been found that 16 gauge metal is acceptable for stair
tread members 50. Examples of commercially available polyurethane
spray coatings which may be used with this invention include
Bullhide.TM. manufactured by Bullhide, Inc.
51. The specific amount of coatings applied to the components may
vary as desired. In practice, it has been found that the lower
surfaces of the components are adequately covered with a 60 mil
covering, and the upper surfaces are adequately covered with an 80
mil coating. For the second coating applied over the dispersed
layer of particles, 40 mils has been found to be adequate. The
polyurethane spray will adequately dry and cure by air drying. No
heat treatment is required.
52. For the first embodiment, there is no requirement that the
wearing surfaces of the existing staircase be repaired or otherwise
prepared. For example, damage to the stair treads in the form of
holes or other imperfections do not have to be filled prior to
installing the invention. Because the invention includes continuous
sheets of high strength material, they are able to cover
imperfections in the underlying surfaces yet provide the desired
walking or wear surfaces. Of course, if the existing staircase is
structurally unstable, it must be repaired prior to installing the
invention.
53. One clear advantage of the invention is the simplicity of its
construction. The components making up each of the embodiments are
simply bent sheets of metal encapsulated within a synthetic
coating. An integral slip-free tread surface is formed directly on
the first coating. The invention may also be adapted for use with
literally any type of staircase or stairway requirement. Each of
the components may be sized and bent to specifications without
altering the general principles of the invention. Furthermore, the
invention can be constructed with relatively simple machinery and
processes. A standard metal break machine may be used to bend the
components to desired shapes. Polyurethane as a spray coating is
readily available and can be applied with standard industrial
sprayers. Since no heat treating is required, the polyurethane
coatings may simply air dry. Any number of differing types of
particles may be used to create the slip-free wearing surfaces.
Depending upon the application, the particles may be applied in a
mixture, or by themselves in a homogenous layer. Yet another
advantage of this invention is the ease with which it is installed.
Standard fasteners such as screws or bolts are used to assemble the
components, along with adhesive or glue, as necessary. No special
tools are required for assembly, and the components are easily
shipped and stored.
54. A heating assembly 90 is shown in FIGS. 14-16 which is intended
to melt ice and snow that accumulates on stair tread 26. A riser 12
having a vertical riser surface 28 and an outwardly projecting
flange 22 are incorporated in the stairway, as previously
described. The heating assembly 90 is in contiguous contact with
stair tread 26. As best seen in FIG. 16, it has a metal stair tread
member 92. A strip heater 94 is attached to and is held in contact
with the bottom surface of stair tread member 92 by means of a
gasket 96. As can be seen, the strip heater 94 is tapered at the
peripheral edge and gasket 96, which extends around the peripheral
edge of strip heater 94, provides a thickness which is
substantially the same as the body of strip heater 94 so that the
heater assembly 90 is substantially flat along its bottom surface
and rests firmly on stair tread 26 without rocking.
55. Advantageously, a first covering 98 of synthetic material
encapsulate the upper horizontal surface of stair tread member 92
along with strip heater 94 and gasket 96 on the bottom surface of
stair tread member 92. A dispersed layer of particles 100 are
placed on the upper surface of first covering 98. A second covering
102 is placed on the dispersed layer of particles 100 encapsulating
them between first covering 98 and second covering 102. When strip
heater 94 is heated, the heat is transferred by conduction through
metal stair tread member 92 and then through first covering 98, the
dispersed layer of particles 100 and second covering 102 to melt
the ice and snow.
56. A thermostat 104 is mounted in a convenient location, such as
on the side of the stairway, as shown in FIG. 14. The thermostat is
connected by means of at outlet 106 to a suitable power source (not
shown). The thermostat 104 has an electrical conduits 108 which
runs to the respective heating assemblies 90 on each step.
Conveniently, a wire 110 extends from the end of each strip heater
94 and terminates in a connector 112 which plugs into a receptacle
114 in each conduit 108.
57. Thermostat 104 selectively supplies electric current to the
strip heaters 94 in response to changes in ambient temperature.
Additionally, thermostat 104 has multiple settings which are
manually selected for providing different selected current levels
to the strip heaters 94 in response to the changes sensed by
temperature sensing element 105 which senses ambient temperature
and is in electrical communication with the thermostat 104, as
shown in FIG. 14. The thermostat selectively supplies a greater or
lesser amount of current depending on its manual setting in
contemplation of the expected ambient temperature and the location
of the stairway. In other words, a greater amount current is
required if the ambient temperature is expected to be below 0
degrees Fahrenheit than if it is expected to be 25 degrees
Fahrenheit. Similarly, if the stairway is on the north side of a
building or in a shady area more current is required that if it is
in a sunny area.
58. This invention has been described in detail with reference to
particular embodiments thereof, but it will be understood that
various other modifications can be effected within the spirit and
scope of this invention.
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