U.S. patent application number 10/143161 was filed with the patent office on 2003-11-13 for lift anchor for concrete panel.
This patent application is currently assigned to Dayton Superior Corporation. Invention is credited to Caldwell, James Leroy, Francies, Sidney E. III, Lancelot, Harry B. III.
Application Number | 20030208969 10/143161 |
Document ID | / |
Family ID | 29400047 |
Filed Date | 2003-11-13 |
United States Patent
Application |
20030208969 |
Kind Code |
A1 |
Lancelot, Harry B. III ; et
al. |
November 13, 2003 |
Lift anchor for concrete panel
Abstract
An anchor for use in a concrete panel that has a shank with four
sides forming a substantially square longitudinal cross-section.
One end of the shank is connected to a foot and is embedable in the
concrete panel. An opposite end of the shank is connected to a head
and is locatable in a recess in the concrete panel.
Inventors: |
Lancelot, Harry B. III;
(Centerville, OH) ; Francies, Sidney E. III;
(Springboro, OH) ; Caldwell, James Leroy; (Fort
Worth, TX) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER
441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
Dayton Superior Corporation
|
Family ID: |
29400047 |
Appl. No.: |
10/143161 |
Filed: |
May 10, 2002 |
Current U.S.
Class: |
52/125.4 ;
52/125.2; 52/125.5 |
Current CPC
Class: |
E04G 21/142
20130101 |
Class at
Publication: |
52/125.4 ;
52/125.5; 52/125.2 |
International
Class: |
E04H 012/34; E04G
021/14; E02D 035/00 |
Claims
What is claimed is:
1. An anchor for use in a concrete panel having a recess in a
surface of the concrete panel, the anchor comprising: a shank
comprising four sides forming a substantially square longitudinal
cross-section, one end adapted to be embedable in the concrete
panel, and an opposite end adapted to extend into the recess in the
concrete panel; a foot connected to the one end of the shank and
adapted to be embedable in the concrete panel; and a head connected
to the opposite end of the shank and adapted to be disposed in the
recess in the concrete panel.
2. An anchor for use in a concrete panel having a recess in a
surface of the concrete panel, the anchor comprising: a forged
unitary body comprising a shank comprising four substantially
mutually perpendicular sides of equal width and forming a
substantially square longitudinal cross-section, one end adapted to
be embedable in the concrete panel, and an opposite end adapted to
extend into the recess in the concrete panel; a foot connected to
the one end of the shank and adapted to be embedable in the
concrete panel, the foot having a substantially circular
longitudinal cross-section; and a head connected to an opposite end
of the shank and adapted to be disposed in the recess in the
concrete panel, the head having a substantially circular
longitudinal cross-section.
3. The anchor of claim 2 wherein the head comprises: an outward
extending substantially cylindrical portion with a diameter greater
than the width of the sides of the shank; and a head transition
having an outer end connected to the cylindrical portion and an
inner end connected to the opposite end of the shank, the outer end
having a diameter substantially equal to the diameter of the
cylindrical portion and the inner end having a diameter
substantially equal to the width of the sides of the shank.
4. The anchor of claim 3 wherein the head transition has a
centerline cross-sectional profile that is curvilinear between the
ends of the head transition.
5. The anchor of claim 4 wherein the head transition has a partial
spherical shape between the ends of the head transition.
6. The anchor of claim 2 wherein the foot comprises: an outer
substantially cylindrical portion with a diameter greater than the
width of the sides of the shank; and a foot transition having an
outer end connected to the cylindrical portion and an inner end
connected to the one end of the shank, the outer end having a
diameter substantially equal to the diameter of the cylindrical
portion and the inner end having a diameter substantially equal to
the width of the sides of the shank.
7. The anchor of claim 6 wherein the foot transition has a
centerline cross-sectional profile that is curvilinear between the
ends of the foot transition.
8. The anchor of claim 7 wherein the foot transition has a partial
spherical shape between the ends of the foot transition.
9. A structural member comprising: a concrete panel comprising two
substantially parallel major surfaces extending across a length and
width of the concrete panel, at least one end surface extending
between the opposing major surfaces and defining an end of the
concrete panel, a recess disposed in one of the major surfaces of
the concrete panel; and an anchor comprising a shank comprising
four substantially mutually perpendicular planar surfaces forming a
substantially square longitudinal cross-section extending over a
length of the shank, one end disposed in the end of the concrete
panel, and an opposite end extending from the one of the major
surfaces and into the recess, a foot connected to the one end of
the shank and disposed in the concrete panel, and a head connected
to the opposite end of the shank and disposed in the recess in the
concrete panel, the head being adapted to engage a lifting device
for lifting the concrete panel.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to anchors for lifting
heavy loads and, more particularly, anchors of solid material that
are embedded in a concrete member.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an anchor for lifting a
concrete panel by its edge or face. Such a panel is often formed by
pouring concrete into a form or mold at floor level either at, or
remote from, a construction site. After the concrete has set or
hardened, the horizontal panel is first lifted by its face from the
form; and then, the concrete panel is lifted by one end and tilted
upward until it is vertical. Thereafter, the concrete panel can
serve as a wall of a concrete building.
[0003] Heretofore, in the production of tilt-up concrete members or
panels that are to be handled with a face-lifting or edge-lifting
operation, it is the practice to embed anchors of steel or iron in
the concrete panel. A known round lift anchor has a cylindrical rod
with a circular head at one end and a circular foot at an opposite
end. In a face-lifting application, the circular foot is embedded
in a major surface or face of the concrete panel such that the
circular head is located in a recess in the face of the concrete
panel. When lifting operations commence, the cylindrical rod of the
partially embedded anchor is subjected to significant tensile
forces. While known anchors perform well, there is a continuous
effort to improve the lifting capacity of such anchors.
SUMMARY OF THE INVENTION
[0004] The present invention provides a lift anchor that has
improved section properties to better resist axial and bending
forces and thus, has a greater lifting capacity than known
comparable anchors. The lift anchor of the present invention is
especially useful in lifting a concrete panel by its face.
[0005] According to the principles of the present invention and in
accordance with the described embodiments, the invention provides
an anchor for use in lifting a concrete panel. The anchor has a
shank with four sides forming a substantially square longitudinal
cross-section. One end of the shank is embedable in a concrete
panel, and an opposite end of the shank extends into a recess in
the concrete panel. The anchor further has a foot connected to the
one end of the shank and a head connected to the opposite end of
the shank. The foot is thus embedable in the concrete, and the head
is locatable in the recess in the concrete panel. In one aspect of
this invention, the lift anchor is forged from a single piece of
square bar stock.
[0006] These and other objects and advantages of the present
invention will become more readily apparent during the following
detailed description taken in conjunction with the drawings
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a side elevation view of a lift anchor in
accordance with the principles of the present invention.
[0008] FIG. 2 is a cross-sectional view of the lift anchor taken
along line 22 of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0009] Referring to FIGS. 1 and 2, a lift anchor 20 is comprised of
a body 22 having a shank 28 with one end 30 rigidly connected to
and integral with a head 24. An opposite end 32 of the shank 28 is
rigidly connected to and integral with a foot 26. The shank 28 has
a substantially square longitudinal cross-sectional area 29 (FIG.
2). Thus, the shank 28 has four substantially mutually
perpendicular sides 36, 38, 40, 42 of substantially equal length
that define a width of the shank. Further, the square longitudinal
cross-sectional profile of the shank extends over substantially a
full length of the shank 28.
[0010] As used herein, the term "longitudinal cross-section" means
a cross section of the shank 28 taken in a plane substantially
normal to a longitudinal centerline 34 of the shank 28. The term
"centerline cross-section" means a cross-section of the shank 28
taken in a plane that contains the shank centerline 34.
[0011] The anchor head 24 has an outer substantially cylindrical
portion 44, and a head transition 46 that connects the cylindrical
portion 44 with the shank end 30. The head cylindrical portion 44
has a diameter that is greater than the length of the sides of the
shank 28. The head transition 46 has a substantially circular outer
edge 48 that has a diameter substantially equal to the diameter of
the cylindrical portion 44. An inner edge 50 of the head transition
46 has a diameter about equal to the width of the shank 28, that
is, the length of the shank sides 36-42. In a centerline
cross-sectional profile of the shank, the head transition 46 is
curvilinear and more specifically, circular. Thus, the surface 52
of the transition 46 is partially spherical in shape.
[0012] The foot 26 is similarly shaped to the head 24 and has an
outer cylindrical portion 54 that is connected to the opposite end
32 of the shank 28 by a foot transition 56. The foot cylindrical
portion 54 has a diameter that is larger than the diameter of the
head cylindrical portion 44. The foot transition 56 intersects with
the cylindrical portion 54 along a circular outer edge 58. The foot
transition 56 intersects with the shank opposite end 32 along a
substantially circular inner edge 60. As with the head 24, in a
centerline cross-sectional profile of the shank, the foot
transition 56 is curvilinear and more specifically, circular. Thus,
the foot transition 56 provides a surface 62 that is partially
spherical in shape.
[0013] The lift anchor 20 is drop forged from a piece of square
carbon steel bar stock, for example, grade C-1045. Thus, the head
24, foot 26 and shank 28 form a single integral body 22. In one
embodiment, the lift anchor 20 is formed from square bar stock
having a nominal shank width of 0.75 inches. As will be
appreciated, depending on the application and designed load
carrying capacity, the anchor 20 may vary in length and may be
manufactured from square bar stock having different nominal
sizes.
[0014] In use, a concrete panel is often fabricated in a mold in a
generally horizontal position and must be lifted by its face to
remove it from the mold. To facilitate that face-lifting operation,
the lift anchor 20 is molded into a face 65 of a concrete panel 66.
The face 65 is one of two substantially parallel opposed surfaces
of the concrete panel 66 and thus, the anchor 20 extends across a
thickness of the concrete panel 66 as represented by the arrow 68.
The face 65 has a generally spherically shaped void 76 containing
the lift anchor head 24.
[0015] Prior to molding the concrete panel 66, the lift anchor 20
is supported and oriented in a substantially vertical position in a
known manner in a concrete form or mold (not shown). The following
discussion with respect to the lift anchor 20 applies to other
anchors substantially identical to the lift anchor 20 that may be
required to lift the concrete panel 66 by its face.
[0016] A void mold 74 is used to form the cavity or void 76. The
void mold 74 is mounted at the shank outer end 30. Referring to
FIG. 2, the void mold 74 has an opening 78 with a square
longitudinal cross-section that is sized to fit around the
perimeter of the square longitudinal cross-sectional area 29 of the
shank 28. The square cross-sectional profiles of the shank 28 and
opening 78 permits the void mold to be mounted and secured at a
desired orientation; and the void mold 74 is unable to rotate with
respect to the centerline 34. In contrast, with a cylindrical
shank, the void mold is able to rotate on the shank; and other
steps must be taken to secure the void mold in its desired
orientation. After the void mold 74 is mounted on the shank 28, the
concrete is poured into the concrete form in order to produce the
concrete panel 66 with the lift anchor 20 disposed therein. After
the concrete sets, the void mold 74 is removed in a known manner;
and the head 24 is left disposed in the cavity 76.
[0017] Subsequently, a lifting device (not shown) is hooked under
the head 24 within the cavity 76; and a lifting force is applied to
the lift anchor 20 such that the face 65 of the concrete panel 66
is moved generally vertically upward as viewed in FIG. 1.
[0018] The square shank lift anchor 20 provides a substantial
advantage over a comparable known cylindrical shank lift anchor.
The square longitudinal cross-section of the shank 28 provides an
area that is larger than a cylindrical cross-section of a
cylindrical shank lift anchor of the same nominal size. That is, a
square shanked lift anchor made from 0.75 inch square bar stock has
a larger longitudinal cross-sectional area than a cylindrical shank
lift anchor made from 0.75 inch round bar stock. Thus, the square
shank 28 is stronger than its comparable cylindrical shank and is
less likely to bend.
[0019] While the invention has been illustrated by the description
of one embodiment and while the embodiment has been described in
considerable detail, there is no intention to restrict nor in any
way limit the scope of the appended claims to such detail.
Additional advantages and modifications will readily appear to
those who are skilled in the art. For example, in the described
embodiment, the head 24 and foot 26 are illustrated and described
to have a generally circular shape. As will be appreciated, there
may be lift anchor applications where it is desirable that the head
24 and/or the foot 26 have a different configuration or shape.
Further, in the described embodiment, the lift anchor 20 is used to
lift a concrete panel 66 by its face 65. As will be appreciated, in
other applications, the anchor 20 and an associated recess can also
be molded in an end surface of the concrete panel, so that the
anchor 20 can be used in an edge-lifting operation.
[0020] Therefore, the invention in its broadest aspects is not
limited to the specific details shown and described. Consequently,
departures may be made from the details described herein without
departing from the spirit and scope of the claims which follow.
* * * * *