U.S. patent application number 10/288912 was filed with the patent office on 2004-05-06 for expansion joint cover.
Invention is credited to Hilburn, Johnnie D..
Application Number | 20040083669 10/288912 |
Document ID | / |
Family ID | 32175996 |
Filed Date | 2004-05-06 |
United States Patent
Application |
20040083669 |
Kind Code |
A1 |
Hilburn, Johnnie D. |
May 6, 2004 |
Expansion joint cover
Abstract
An expansion joint cover (10) broadly comprises a cover plate
(38) to cover an expansion joint (12) between a first and second
surface (14,16), an anchor assembly (40) to secure the plate (38)
to the first surface (14), an insert (46) to protect the second
surface (16), and one or more resilient bushings (48) to isolate
the plate (38) from the anchor assembly (40). Under adverse
conditions, such as during seismic events, the surfaces (14,16) may
move significantly with respect to one another, thereby causing the
plate (38) to slide over the second surface (16) and the insert
(46) and deform the bushings (48). Thus, the flexibility of the
plate (38), the durability of the insert (46), and the resilience
of the bushings (48) all cooperate to allow the cover (10) to
minimize stresses otherwise transferred to the anchor assembly
(40).
Inventors: |
Hilburn, Johnnie D.;
(Wichita, KS) |
Correspondence
Address: |
THOMAS B. LUEBBERING
HOVEY WILLIAMS LLP
2405 Grand, Suite 400
Kansas City
MO
64108
US
|
Family ID: |
32175996 |
Appl. No.: |
10/288912 |
Filed: |
November 5, 2002 |
Current U.S.
Class: |
52/396.04 ;
52/396.05; 52/466; 52/469; 52/573.1 |
Current CPC
Class: |
E04B 1/681 20130101 |
Class at
Publication: |
052/396.04 ;
052/573.1; 052/396.05; 052/466; 052/469 |
International
Class: |
E04B 001/68 |
Claims
Having thus described a preferred embodiment of the invention, what
is claimed as new and desired to be protected by Letters Patent
includes the following:
1. An expansion joint cover operable to cover an expansion joint
between a first surface and a second surface, the cover comprising:
a cover plate operable to span the joint; an anchor operable to
penetrate the plate, thereby securing the plate to the first
surface; and a bushing between and operable to physically isolate
the plate and the anchor.
2. The cover as set forth in claim 1, wherein the bushing is
resilient and thereby further operable to allow the plate to move
with respect to the anchor allowing the cover to accommodate
movement between the surfaces.
3. The cover as set forth in claim 1, wherein the anchor is secured
directly into the first surface.
4. The cover as set forth in claim 1, wherein the anchor includes a
concrete anchor member disposed within a hole in the first surface
and a fastener threaded into the concrete anchor member.
5. The cover as set forth in claim 1, wherein the bushing includes
a circular face and a cylindrical sleeve.
6. The cover as set forth in claim 5, wherein the face is
approximately one and one half inches in diameter and approximately
three sixteenths of an inch thick.
7. The cover as set forth in claim 5, wherein the sleeve has an
approximately one half inch internal diameter that tightly fits
around at least a portion of the anchor.
8. The cover as set forth in claim 5, wherein the 1 sleeve has an
approximately three quarters of an inch external diameter that
tightly fits within a penetration in the plate.
9. The cover as set forth in claim 5, wherein the sleeve has an
approximately three eighths of an inch length allowing the sleeve
to substantially completely penetrate the plate.
10. An expansion joint cover operable to cover an expansion joint
between a first surface and a second surface, the cover comprising:
a cover plate operable to span the joint; an anchor secured
directly into the first surface and operable to penetrate the
plate, thereby securing the plate to the first surface; and a
resilient bushing between and operable to physically isolate the
plate and the anchor, thereby operable to allow the plate to move
with respect to the anchor allowing the cover to accommodate
movement between the surfaces.
11. The cover as set forth in claim 10, wherein the anchor includes
a concrete anchor member disposed within a hole in the first
surface and a fastener threaded into the concrete anchor
member.
12. The cover as set forth in claim 10, wherein the bushing
includes a circular face and a cylindrical sleeve.
13. The cover as set forth in claim 12, wherein the face is
approximately one and one half inches in diameter and approximately
three sixteenths of an inch thick.
14. The cover as set forth in claim 12, wherein the sleeve has an
approximately one half inch internal diameter that tightly fits
around at least a portion of the anchor.
15. The cover as set forth in claim 12, wherein the sleeve has an
approximately three quarters of an inch external diameter that
tightly fits within a penetration in the plate.
16. The cover as set forth in claim 12, wherein the sleeve has an
approximately three eighths of an inch length allowing the sleeve
to substantially completely penetrate the plate.
17. An expansion joint cover operable to cover an expansion joint
between a first surface and a second surface, the cover comprising:
a cover plate operable to span the joint; an anchor assembly
including a concrete anchor member disposed within a hole in the
first surface, and a fastener threaded into the concrete anchor
member and operable to penetrate the plate, thereby securing the
plate to the first surface; and a flexible bushing between and
operable to physically isolate the plate and the anchor, the
bushing including a circular face approximately one and one half
inches in diameter and approximately three sixteenths of an inch
thick, and a cylindrical sleeve with an approximately one half inch
internal diameter that tightly fits around the fastener, an
approximately three quarter inch external diameter that tightly
fits within a penetration in the plate, and an approximately three
eighths of an inch length allowing the sleeve to substantially
completely penetrate the plate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to expansion joints and
expansion joint covers. More particularly, the present invention
relates to an expansion joint cover that can be installed over an
expansion joint between a first surface and a second surface.
[0003] 2. Description of Prior Art
[0004] Prior art expansion joint covers include cover plates
covering expansion joints between first and second building
surfaces. Typically, a first edge of the plate is coupled to the
first surface and an opposed second edge is slidably received in a
transition recess defined in the second surface. The second edge
slides in the recess during relative movement of the surfaces
caused by thermal expansion and contraction.
[0005] The second surface typically presents a beveled recess wall
where the recess meets an adjacent upper surface of the second
surface. During a seismic event, the joint may narrow such that the
second edge of the plate slides over the recess wall onto the upper
surface of the second surface. The recess wall is therefore subject
to spalling, corrosion and potential impact damage from the second
edge of the plate during a seismic event. Additionally, stresses
involved with the plate sliding onto the upper surface are
typically transferred to bolts anchoring the plate, thereby
inducing shock and shear forces capable of damaging the bolts.
[0006] Furthermore, since the plate and the bolts may be
constructed of dissimilar metals, electrolysis may lead to galvanic
corrosion of either the plate, the bolts, or both. Additionally,
the movement described above can be quite noisy.
[0007] Finally, prior art expansion joint systems are typically
designed for installation during building construction. As a
result, installation on an existing building as a retrofit can be
expensive and labor intensive.
[0008] Accordingly, there is a need for an improved expansion joint
cover that overcomes the limitations of the prior art.
SUMMARY OF THE INVENTION
[0009] The present invention overcomes the above-identified
problems and provides a distinct advance in the art of expansion
joint covers. More particularly, the present invention relates to
an expansion joint cover that can be installed over an expansion
joint between a first surface and a second surface. The cover
broadly comprises a cover plate to cover the joint, an anchor
assembly to secure the plate, a transition insert to protect the
second surface, and one or more bushings to isolate the plate from
the anchor assembly. The plate preferably presents a first edge
positioned adjacent the first surface and a second edge positioned
adjacent the second surface.
[0010] The anchor assembly preferably includes one or more concrete
anchor members each inserted into a hole in the first surface and
one or more bolts each threaded into one of the concrete anchor
members. The insert protects the second surface from impact damage
by the second edge of the plate during a seismic event.
[0011] Each bushing is preferably made of polyurethane or another
resilient material, such as cork, rubber, or other flexible
elastomer, and comprises a circular face positioned between the
plate and the head of one of the bolts and a cylindrical sleeve
positioned between the plate and the shank of one of the bolts. The
sleeve preferably fits tightly between the shank and one of several
penetrations in the plate, thereby securely holding the plate in
position relative to the bolts.
[0012] Under normal conditions, such as during thermal expansion
and contraction, the surfaces may move slightly with respect to one
another. In this case, the plate slides over the second surface
with minimal deformation of the plate and the bushings. Under
adverse conditions, such as during seismic events, the building
surfaces may move significantly with respect to one another. In
this case, the plate slides over the second surface, may flex and
slide over the insert, and may deform the bushings. Thus, the
flexibility of the plate, the durability of the insert, and the
resilience of the bushings all cooperate to allow the cover to
minimize stresses otherwise transferred to the anchor assembly.
Such stresses may otherwise shear the bolts, cause damage to the
surfaces, or both.
[0013] Additionally, the bushings accommodate minor misalignment
between the bolts and the penetrations in the plate. Such
misalignment may occur during construction of the building,
installation of the cover, or during the cover's service life.
Without the bushings, the misalignment would otherwise induce
stress on the anchor assembly leading to the damage described
above.
[0014] Furthermore, the bushings prevent metal-to-metal contact
between the plate and the bolts. Since the plate and the bolts may
be constructed of dissimilar metals, electrolysis may otherwise
lead to galvanic corrosion of either the plate, the bolts, or both.
Additionally, the bushings minimize any noise associated with the
movement described above. Finally, it can be seen that the bushings
absorb any shock that may be associated with the movement described
above, thereby reducing any such effects experienced by the anchor
assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A preferred embodiment of the present invention is described
in detail below with reference to the attached drawing figures,
wherein:
[0016] FIG. 1 is a perspective view of an expansion joint cover 10
constructed in accordance with a preferred embodiment of the
present invention and shown covering an expansion joint;
[0017] FIG. 2 is an elevation view of the cover;
[0018] FIG. 3 is a plan view of a bushing of the cover; and
[0019] FIG. 4 is an elevation view of the bushing.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0020] Referring to FIG. 1, an expansion joint cover 10 is shown
constructed in accordance with a preferred embodiment of the
present invention. The cover 10 is used to cover an expansion joint
12 between a first building surface 14 and a second building
surface 16 of a building such as a parking garage. Such building
surfaces 14, 16 are typically composed of concrete. However, the
surfaces 14,16 can have similar or different configurations and
textures and may be parallel, perpendicular, or otherwise situated
relative to each other.
[0021] Referring also to FIG. 2, the first surface 14 preferably
presents a first upper surface 18 and a mounting recess 20
preferably having a depth of approximately three quarters of an
inch adjacent the joint 12. The mounting recess 20 preferably
presents a first support surface 22 and a first recess wall 24
between the first upper surface 18 and the first support surface
22.
[0022] Similarly, the second surface 16 preferably presents a
second upper surface 28 and a transition recess 30 preferably
having a depth of about three quarters of an inch adjacent the
joint 12. The transition recess 30 preferably presents a second
support surface 32 and a second recess wall 34 between the second
upper surface 28 and the second support surface 32. The support
surfaces 22,32 are preferably substantially aligned, such that they
are planar, in order to allow the cover 10 to effectively cover the
joint 12.
[0023] Either recess 20,30 may be pre-existing in the corresponding
building surfaces 14,16 or may be cut into the building surfaces
14,16, in order to accommodate the cover 10. Alternatively, the
cover 10 may be installed on the building surfaces 14,16 without
either one or both of the recesses 20,30. However, this typically
requires the cover 10 to protrude well beyond the building surfaces
14,16, and therefore may not be desired.
[0024] The cover 10 broadly comprises a cover plate 38 to cover the
joint 12, an anchor assembly 40 to secure the plate 38, a first and
second support pad 42,44 to support the plate 38, a transition
insert 46 to protect the second building surface 16, and one or
more bushings 48 to isolate the plate 38 from the anchor assembly
40. The plate 38 is preferably composed of approximately three
eighths of an inch thick bent aluminum plate to present an
approximately one half inch arch for increased structural strength,
as illustrated in FIG. 2. The plate 38 extends along the joint's 12
length and is wide enough to span the joint 12. Therefore, the
plate's 38 length and width are dependent upon dimensions of the
joint 12. The plate 38 preferably presents a first edge 50
positioned in the mounting recess 20 and a second edge 52
positioned in the transition recess 30. Either edge 50,52 may be
beveled in order to avoid presenting sharp corners.
[0025] The anchor assembly 40 preferably includes one or more
concrete anchor members 54 each inserted into a hole in the first
building surface 14 and one or more bolts 56 each threaded into one
of the concrete anchor members 54. Each concrete anchor member 54
is preferably conventional and constructed of plastic. Each bolt 56
preferably includes a bolt head 58, a threaded end, and a shank 62
therebetween. The head 58 preferably resides external to the plate
38 and holds the plate 38 adjacent the joint 12. The threaded end
preferably mates with the concrete anchor member 45 and holds the
bolt 56 in place. The shank 62 preferably extends through one of
several penetrations in the plate 38 adjacent the first edge 50 and
through the first pad 42 and the bushing 48.
[0026] Alternatively, the anchor assembly 40 may include one or
more bolts 56 cast directly into the concrete making up the first
building surface 14. In this case, the anchor assembly 40 may also
include a nut threaded onto each bolt 56 to secure the plate 38
over the joint 12.
[0027] The pads 42,44, are preferably approximately three eighths
of an inch thick and preferably composed of a resilient, synthetic
material, such as neoprene. The first pad 42 is preferably
positioned in the mounting recess 20 between the first edge 50 of
the plate 38 and the first support surface 22 and between the joint
12 and the first recess wall 24. The first pad 42 supports the
first edge 50 of the plate 38 and allows the plate 38 to flex and
move relative to the first building surface 14.
[0028] Similarly, the second pad 44 is preferably positioned in the
transition recess 30 between the second edge 52 of the plate 38 and
the second support surface 32 and between the joint 12 and the
second recess wall 34. The second pad 44 supports the second edge
52 of the plate 38 and allows the second edge 52 to slide thereon
during relative movement between the building surfaces 14,16.
[0029] The insert 46 is preferably integrally formed of metal, such
as steel, aluminum, synthetic resin material, fiberglass, or a
composite material. Such materials are chosen as needed to
withstand expected loads of a particular installation. The insert
46 is preferably positioned in the transition recess 30 on the
second support surface 32 and against the second recess wall 34.
The insert 46 is preferably beveled in order to avoid presenting
sharp corners and in order to present a smooth transition wall 64
between the second support surface 32 and the second upper surface
28. In particular, the transition wall 64 provides a transition
between an upper face 66 of the second pad 44 and the second upper
surface 28.
[0030] In the preferred embodiment, the transition recess 30 is
wide enough so that the second edge 52 remains therein supported by
the second pad 44 during expected widening and narrowing of the
joint 12 due to thermal expansion and contraction. However, during
a seismic event, the building surfaces 14,16 may move toward one
another so that the second edge 52 slides over the transition wall
64 and onto the second upper surface 28. During such movement, the
transition wall 64 guides the second edge 52 between the upper face
66 of the second pad 44 and the second upper surface 28.
[0031] The insert 46 is preferably constructed of materials less
subject to spalling and corrosion than the concrete making up the
second recess wall 34. Because of this, the insert 46 ensures
reliable operation of the cover 10 for many years. Moreover, the
insert 46 protects the second recess wall 34 from impact damage by
the second edge 52 during a seismic event.
[0032] Referring also to FIGS. 3 and 4, each bushing 48 is
preferably made of polyurethane or another resilient material, such
as cork, rubber, or other flexible elastomer, and comprises a
circular face 68 positioned between the plate 38 and the head 58 of
one of the bolts 56 and a cylindrical sleeve 70 positioned between
the plate 38 and the shank 62 of one of the bolts 56. The face 68
is preferably approximately one and one half inches in diameter and
approximately three sixteenths of an inch thick. The sleeve 70
preferably includes an approximately one half inch internal
diameter 72 that tightly fits around the shank 62, an approximately
three quarters of an inch external diameter 74 that tightly fits
within one of the penetrations in the plate 38, and an
approximately three eighths of an inch length allowing the sleeve
70 to substantially completely penetrate the plate 38. Thus, the
bushings 48 securely hold the plate 38 in position relative to the
bolts 56, which are secured to the first building surface 14.
[0033] Under normal conditions, such as during thermal expansion
and contraction, the building surfaces 14,16 may move slightly with
respect to one another. In this case, the plate 38 slides over the
second pad 44 with minimal deformation of the plate 38, the pads
42,44, and the bushings 48. Under adverse conditions, such as
during seismic events, the building surfaces 14,16 may move
significantly with respect to one another. In this case, the plate
38 slides over the second pad 44, may deform either of the pads
42,44 and the bushings 48, and may flex and slide over the
transition wall 64 of the insert 46. Thus, the flexibility of the
plate 38, the resilience of the pads 42,44 and the bushings 48, and
the durability of the insert 46 all cooperate to allow the cover 10
to minimize stresses otherwise transferred to the anchor assembly
40. Such stresses may otherwise shear the bolts 56, cause damage to
the building surfaces 14,16, or both.
[0034] Additionally, the bushings 48 accommodate minor misalignment
between the bolts 56 and the penetrations in the plate 38. Such
misalignment may occur during construction of the building,
installation of the cover 10, or during the cover's 10 service
life. Without the bushings 48, the misalignment would otherwise
induce stress on the anchor assembly 40 leading to the damage
described above.
[0035] Furthermore, the bushings 48 prevent metal-to-metal contact
between the plate 38 and the bolts 56. Since the plate 38 and the
bolts 56 maybe constructed of dissimilar metals, electrolysis may
otherwise lead to galvanic corrosion of either the plate 38, the
bolts 56, or both. Additionally, the bushings 48 minimize any noise
associated with the movement described above. Finally, it can be
seen that the bushings 48 absorb any shock that may be associated
with the movement described above, thereby reducing any such
effects experienced by the anchor assembly 40.
[0036] While the present invention has been described above, it is
understood that other materials and/or dimensions can be
substituted. For example, the face 68 of the bushings 48 maybe
between one inch and two inches in diameter, and between one
sixteenth of an inch and one half inch thick; but, are preferably
sized to be wider than the head 58 of the bolts 56. The bushings 48
may resemble a grommet and comprise two faces 68 each disposed at
opposing ends of the sleeve 70. In this case, the faces 68 may have
diameters that differ from one another. Additionally, the internal
diameter 72 of the sleeve 70 may be between one quarter inch and
three quarter inches; but, is largely dependent upon the diameter
of the shank 62 of the bolts 56. Furthermore, the external diameter
74 of the sleeve 70 maybe between one half inch and one inch; but,
is largely dependent upon the diameter of the penetrations in the
plate 38. Finally, the length of the sleeve 70 may be between one
quarter inch and one half inch; but, is largely dependent upon the
thickness of the plate 38. In this manner, the dimensions of the
bushings 48 may be chosen to accommodate the dimensions of the
plate 38 and the bolts 56. These and other minor modifications are
within the scope of the present invention.
* * * * *