U.S. patent number RE46,831 [Application Number 15/399,338] was granted by the patent office on 2018-05-08 for lifting and leveling assembly for precast concrete slabs and method.
The grantee listed for this patent is Sidney E. Francies, III. Invention is credited to Sidney E. Francies, III.
United States Patent |
RE46,831 |
Francies, III |
May 8, 2018 |
Lifting and leveling assembly for precast concrete slabs and
method
Abstract
A lifting and leveling assembly configured to be embedded in a
precast concrete slab for lifting a leveling a precast concrete
slab includes a base plate, a threaded sleeve, an anchor plate, a
thread protecting sleeve, a threaded lifting bolt and an end cap.
Rotating the threaded lifting bolt in a first direction positions a
bolt head on the threaded lifting bolt above a top surface of a
precast concrete slab to accommodate the attachment of a lifting
device. Rotating the threaded lifting bolt in a second direction
positions the bolt head beneath the top surface of the concrete
slab and causes the threaded shaft to exert a force on the base
plate to level the precast concrete slab.
Inventors: |
Francies, III; Sidney E.
(Lithia, FL) |
Applicant: |
Name |
City |
State |
Country |
Type |
Francies, III; Sidney E. |
Lithia |
FL |
US |
|
|
Family
ID: |
55969613 |
Appl.
No.: |
15/399,338 |
Filed: |
January 5, 2017 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
61950344 |
Mar 10, 2014 |
|
|
|
Reissue of: |
14595721 |
Jan 13, 2015 |
9347232 |
May 24, 2016 |
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04B
5/04 (20130101); B66C 1/666 (20130101); E04G
15/04 (20130101); E04G 21/142 (20130101); E04G
21/142 (20130101); E04B 5/04 (20130101); E04B
1/3511 (20130101); B66F 3/08 (20130101) |
Current International
Class: |
E02D
35/00 (20060101); E04G 21/14 (20060101); E04B
5/04 (20060101); E04B 1/35 (20060101); B66F
3/08 (20060101) |
Field of
Search: |
;52/125.4,125.2,125.5,745.2,126.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Flanagan; Beverly M
Attorney, Agent or Firm: McGarry Bair PC
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent
Application No. 61/950,344, filed Mar. 10, 2014 which is
incorporated herein by reference in its entirety.
Claims
What is claimed is:
1. A lifting and leveling assembly configured to be embedded in a
precast concrete slab and for lifting and leveling the same, the
lifting and leveling assembly comprising: an internally threaded
sleeve; a threaded lifting bolt threaded into the threaded sleeve
and including a threaded shaft and a bolt head; a hollow thread
protecting sleeve disposed at least in part above the threaded
sleeve and encompassing an upper portion of the threaded shaft; a
removable end cap selectively covering the bolt head; a base plate
configured for supporting relationship with the threaded sleeve;
and an outer housing surrounding the threaded sleeve and base plate
to releasably bind the two together, wherein the outer housing
surrounds at least a portion of the threaded lifting bolt and the
thread protecting sleeve is slidably received in an upper portion
of the outer housing.
2. The lifting and leveling assembly of claim 1 and further
comprising an anchor fixedly attached to the threaded sleeve and
extending transversely thereof.
3. The lifting and leveling assembly of claim 2 wherein the anchor
and threaded sleeve are integral.
4. The lifting and leveling assembly of claim 1 wherein the anchor
comprises a plate that extends 360.degree. around the threaded
sleeve.
5. The lifting and leveling assembly of claim 4 wherein the anchor
plate is rectangular.
6. The lifting and leveling assembly of claim 1 wherein the thread
protecting sleeve is adjustably retained within the outer housing
to adjust an overall height the lifting and leveling assembly
defined by the height between the base plate and the top surface of
the end cap.
7. The lifting and leveling assembly of claim 6 wherein the height
of the thread protecting sleeve relative to the outer housing is
adjustable and threaded lifting bolt corresponds to the overall
height of the overall height the lifting and leveling assembly.
8. The lifting and leveling assembly of claim 7 wherein the outer
housing includes a height adjustment track and the thread
protecting sleeve includes a protrusion that rides in the height
adjustment track, and the height adjustment track includes a
plurality of locking recesses positioned along height adjustment
track, the locking recesses configured to receive the protrusion to
position and retain the thread protecting sleeve in the outer
housing at predetermined heights.
9. The lifting and leveling assembly of claim 7 and further
comprises a detent mechanism between the thread protecting sleeve
and the outer housing for selectively adjusting the height of the
thread protecting sleeve with respect to the outer housing.
10. The lifting and leveling assembly of claim 1 wherein the outer
housing covers a top surface of the base plate to reduce adhesion
between the base plate and the precast concrete slab.
11. The lifting and leveling assembly of claim 1 wherein the outer
housing includes a base plate retainer configured to releasably
retain the base plate within the outer housing.
12. The lifting and leveling assembly of claim 1 wherein the outer
housing is formed from two identical halves which are configured to
be joined together around the threaded sleeve and base plate.
13. The lifting and leveling assembly of claim 12 wherein the two
identical halves are joined together along a vertical seam.
14. The lifting and leveling assembly of claim 1, further
comprising an internally threaded collar threaded onto an upper
portion of the threaded shaft and within the thread protecting
sleeve.
15. The lifting and leveling assembly of claim 14 wherein the
removable end cap has head engaging bosses to center the removable
end cap on the bolt head and extend to the internally threaded
collar.
16. A precast concrete slab with at least one lifting and leveling
assembly according to claim 1 wherein the removable end cap has an
upper surface that is flush with an upper surface of the precast
concrete slab and the base plate has a lower surface that is flush
with a lower surface of the precast concrete slab.
17. The lifting and leveling assembly of claim 1 and further
comprising a hollow cylinder that is affixed to the base plate and
slidably receives a lower portion of the internally threaded
sleeve.
18. A precast concrete slab with at least one lifting and leveling
assembly according to claim 17 embedded therein wherein and the
base plate has a lower surface that is flush with a lower surface
of the precast concrete slab.
19. The lifting and leveling assembly of claim 1 wherein the
removable end cap has head engaging bosses to center the removable
end cap on the bolt head.
.Iadd.20. A lifting and leveling assembly configured to be embedded
in a precast concrete slab and for lifting and leveling the same,
the lifting and leveling assembly comprising: an anchoring assembly
including an internally threaded sleeve having an upper portion and
lower portion; a base plate configured for supporting relationship
with the internally threaded sleeve; a hollow thread protecting
sleeve disposed at least in part above the internally threaded
sleeve and mounted to the upper portion of the internally threaded
sleeve; and a base plate cover mounted to the lower portion of the
internally threaded sleeve; wherein the base plate cover is
configured to selectively retain the base plate and to shield the
base plate from concrete during casting of the concrete slab, and
when the concrete slab is cast, is configured to detach from the
base plate and remain with the concrete slab as rotation of a bolt
in the internally threaded sleeve causes the anchoring assembly to
move away from the base plate. .Iaddend.
.Iadd.21. The lifting and leveling assembly of claim 19 wherein the
hollow thread protecting sleeve is adjustably mounted to the upper
portion of the internally threaded sleeve. .Iaddend.
.Iadd.22. The lifting and leveling assembly of claim 20 wherein the
hollow thread protecting sleeve has a lower hollow cylinder
configured to flex radially. .Iaddend.
.Iadd.23. The lifting and leveling assembly of claim 19 wherein the
base plate cover has an upstanding cylinder configured to flex
radially. .Iaddend.
.Iadd.24. The lifting and leveling assembly of claim 19 wherein the
hollow thread protecting sleeve and the base plate cover are formed
from plastic. .Iaddend.
.Iadd.25. The lifting and leveling assembly of claim 19 further
comprising a removable end cap on the hollow thread protecting
sleeve. .Iaddend.
.Iadd.26. A lifting and leveling assembly configured to be embedded
in a precast concrete slab and for lifting and leveling the same,
the lifting and leveling assembly comprising: an anchoring assembly
including an internally threaded sleeve having an upper portion and
lower portion; a base plate configured for supporting relationship
with the internally threaded sleeve; a hollow thread protecting
sleeve disposed at least in part above the internally threaded
sleeve and mounted to the upper portion of the internally threaded
sleeve; and a base plate cover mounted to the lower portion of the
internally threaded sleeve and configured to selectively retain the
base plate and to shield the base plate from concrete during
casting of the concrete slab, wherein the hollow thread protecting
sleeve has a lower hollow cylinder configured to flex radially.
.Iaddend.
.Iadd.27. A lifting and leveling assembly configured to be embedded
in a precast concrete slab and for lifting and leveling the same,
the lifting and leveling assembly comprising: an anchoring assembly
including an internally threaded sleeve having an upper portion and
lower portion; a base plate configured for supporting relationship
with the internally threaded sleeve; a hollow thread protecting
sleeve disposed at least in part above the internally threaded
sleeve and mounted to the upper portion of the internally threaded
sleeve; and a base plate cover mounted to the lower portion of the
internally threaded sleeve and configured to selectively retain the
base plate and to shield the base plate from concrete during
casting of the concrete slab, wherein the base plate cover has an
upstanding cylinder configured to flex radially. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to the lifting and leveling of
precast concrete slabs for use in the construction or repair of
concrete surfaces.
2. Description of the Related Art
Precast concrete slabs are commonly used in the construction and
repair of concrete surfaces such as concrete roads. Precast
concrete slabs are lifted and placed in excavations and then
leveled to be even with adjacent slabs. Grout is then pumped
underneath the slab to fill and solidify any voids. It is common
for precast concrete slabs to have lifting anchors embedded in the
concrete so that the slabs may be lifted by a crane and rigging
system. The slabs are leveled using precise surveys and excavation,
plastic leveling shims, grout leveling pads or a process known as
"mud jacking"; however, these leveling techniques can be costly and
time consuming.
U.S. Patent Application US2014/0053475 discloses a leveling lift
device embedded in the corners of a precast concrete slabs to aid
in the lifting and leveling of the precast concrete slabs. The
leveling lift device includes a flat base plate, a section of pipe
affixed to and standing upwardly from the base plate, a threaded
hollow sleeve sized such that the bottom is removably received
within the upstanding pipe and a threaded end that is removably
received in the upper portion of the threaded hollow sleeve.
When the leveling lift device is embedded into the concrete slab,
the base plate is located along the bottom of the slab, the
threaded hollow sleeve extends through the slab between the top and
the base plate and the threaded end cap is threaded into the
threaded sleeve to protect the threads on the threaded sleeve. The
end cap has a head which sticks above the upper surface of the
concrete slab so that the end cap can be removed after the slab is
formed. To lift the slab, the end cap is removed and a threaded
bolt is inserted through a lifting device and into the threaded
hollow sleeve to secure a lifting device to the slab. The lifting
bolt is long enough to extend the length of the threaded shaft to a
base plate and to extend above the upper surface of the cement
slab. To level the panel, the threaded bolt is rotated in the
threaded sleeve until it contacts the base plate wherein further
rotation applies a pushing force against the base plate, elevating
the slab above as necessary to make the slab level with adjacent
slabs. When the slab level, the lifting device and threaded bolt
are disposed above the top surface of the panel and grout is pumped
beneath the panel to fill the space between the panel and the
surface below. After allowing the grout or cement to cured, the
threaded bolt and lifting device must be removed from the threaded
sleeve and grout or cement must be pumped into the threaded sleeve
to fill the void left by the lifting bolt.
The lifting and leveling device presents problems during
installation and use, including that the threaded end cap and
separate threaded bolt increases the likelihood of misplaced parts
during installation. Also, the threaded bolt is always disposed
above the surface of the concrete slabs during lifting and
leveling, presenting tripping hazards. The lifting and leveling
device also requires removing the end cap, inserting the threaded
bolt and lifting device and then subsequently removing the threaded
bolt and lifting during casting, lifting, leveling and grouting,
which adds significant time to the construction or repair of
concrete surfaces using precast concrete slabs. The grout beneath
the slab must cure before removing the threaded bolt, which is
required, also adding time the construction or repair. Furthermore,
filling the threaded sleeve with grout or cement prevents
subsequent use of the leveling lift device.
SUMMARY OF THE INVENTION
According to the invention, a lifting and leveling assembly for
lifting and leveling a precast concrete slab and is configured to
be embedded in the precast concrete slab includes a threaded
sleeve; an anchor plate fixedly attached to the threaded sleeve and
extending transversely thereof; a threaded lifting bolt threaded
into the threaded sleeve and including a threaded shaft and a bolt
head; a hollow thread protecting sleeve disposed at least in part
above the threaded sleeve and encompassing an upper portion of the
threaded shaft; a removable end cap selectively covering the bolt
head and; and a base plate beneath the threaded sleeve.
In one embodiment, a threaded collar is threaded onto an upper
portion of the threaded shaft and positioned within the thread
protecting sleeve.
In another embodiment, the anchor plate and the threaded sleeve are
integral. They can be integrally formed or made in two pieces and
welded together.
In another embodiment, the anchor plate extends 360.degree. around
the threaded sleeve.
In yet another embodiment, an outer housing surrounds the threaded
sleeve and base plate. In addition, the outer housing may surround
at least a portion of the threaded lifting bolt. In addition, the
thread protecting sleeve may be slidably received in an upper
portion of the outer housing. Further, the thread protecting sleeve
may be adjustably retained within the outer housing to adjust an
overall height the lifting and leveling assembly defined by the
height between the base plate and the top surface of the end cap.
The height of the thread protecting sleeve relative to the outer
housing may be adjustable. Threaded lifting bolt may also
correspond to the overall height of the overall height the lifting
and leveling assembly. The outer housing may also include a height
adjustment track. A detent mechanism between the thread protecting
sleeve and the outer housing may be provided for selectively
adjusting the height of the thread protecting sleeve with respect
to the outer housing. The detent mechanism may include a protrusion
on the thread protecting sleeve that rides in the height adjustment
track and a plurality of locking recesses positioned along length
of the height adjustment track. The locking recesses are configured
to receive the protrusion to position and retain the thread
protecting sleeve in the outer housing at predetermined
heights.
Preferably, the outer housing covers a top surface of the base
plate to reduce adhesion between the base plate and the precast
concrete slab. In addition, the outer housing may include a base
plate retainer configured to releasably retain the base plate
within the outer housing.
In one embodiment, the outer housing is formed from two identical
halves which are configured to be joined together around the
threaded sleeve and base plate. The two identical halves may be
joined together along a vertical seam.
Rotating the exposed bolt head of the threaded lifting bolt in a
first direction positions the bolt head above the top surface of
the precast concrete slab to accommodate the attachment of a
lifting device. Rotating the exposed bolt head of the threaded
lifting bolt in a second direction positions the bolt head beneath
the top surface of the concrete slab and raises the level of the
precast concrete slab.
Further according to the invention, a method of making a lifting
and leveling cement slap comprises placing at least one lifting and
leveling assembly according as described above into a concrete mold
wherein the removable end cap has an upper portion that is abuts an
upper surface of the concrete mold and the base plate has a lower
surface that abuts a lower portion of the concrete; pouring
concrete into the concrete mold; curing the concrete to form a
cement slab with the at least one lifting and leveling
assembly.
Still further according to the invention, a method of leveling a
cement slab in an excavation bed comprises incorporating into a
cement slab at least one lifting and leveling assembly as described
above wherein the removable end cap has an upper surface that is
flush with an upper surface of the precast concrete slab and the
base plate has a lower surface that is flush with a lower surface
of the precast concrete slab; removing the removable end cap from
the or each at least one lifting and leveling assembly; placing the
cement slab in an excavation bed adjacent other cement slabs;
rotating the threaded lifting bolt of the or each of the at least
one lifting and leveling assembly to adjust the height of the
cement slab to conform with the height of the adjacent other cement
slabs; and filling any voids between the excavation bed and the
lower surface of the slab with grout; and filling the void between
the top of the threaded lifting bolt and the upper surface of the
cement slab with grout.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an exploded view of a lifting and leveling assembly
according to a first embodiment of the invention.
FIG. 2 is a sectional view of the assembled lifting and leveling
assembly of FIG. 1.
FIG. 3 is a flowchart of method of making and installing a precast
concrete slab using the lifting and leveling assembly of FIG. 1
according to an embodiment of the invention.
FIG. 4 is a sectional view of the lifting and leveling assembly of
FIG. 1 embedded in a concrete slab.
FIG. 5 is a sectional view of a lifting and leveling assembly with
a modified base plate embedded in a concrete slab according to an
embodiment of the invention.
FIG. 6 is a sectional view of the lifting and leveling assembly of
FIG. 1 embedded in a concrete slab of in the lifting position.
FIG. 7 is a sectional view of the lifting and leveling assembly of
FIG. 1 embedded in a concrete slab in the lifting position with a
pivoting lifting eye installed.
FIG. 8 is a sectional view of the lifting and leveling assembly of
FIG. 1 embedded in a concrete slab in a stacking position.
FIG. 9 is a sectional view of the lifting and leveling assembly of
FIG. 1 embedded in a concrete slab in the leveling position.
FIG. 10 is a sectional view of the lifting and leveling assembly
FIG. 5 embedded in a concrete slab in the leveling position.
FIG. 11 is a sectional view of a lifting and leveling assembly of
FIG. 1 embedded in a leveled concrete slab with the voids filled
with grout.
FIG. 12 is a sectional view of a lifting and leveling assembly of
FIG. 1 embedded in a leveled concrete slab with the voids filled
with grout and the end cap placed above the lifting bolt.
FIG. 13 is a perspective view of a lifting and leveling assembly
according to a second embodiment of the invention.
FIG. 14 is a perspective view of an outer housing of the lifting
and leveling assembly of FIG. 13.
FIG. 15 is a vertical sectional view of the lifting and leveling
assembly of FIG. 13 taken along line XV-XV of FIG. 13.
FIG. 16 is a sectional view of the lifting and leveling assembly of
FIG. 13 in a collapsed form.
FIG. 17 is a sectional view of the lifting and leveling assembly of
FIG. 13 embedded in a concrete slab in an initial positon seated in
a roadbed.
FIG. 18 is a sectional view of the lifting and leveling assembly of
FIG. 13 embedded in a concrete slab in a leveled position in a
roadbed.
FIG. 19 is an exploded view of a lifting and leveling assembly
according to a third embodiment of the invention.
FIG. 20 is a perspective view of a thread protecting sleeve of the
lifting and leveling assembly according to another embodiment of
the invention.
FIG. 21 is a sectional view of the lifting and leveling assembly of
FIG. 19 in a first position embedded in a concrete slab in an
initial positon seated in a roadbed.
FIG. 22 is a sectional view of the lifting and leveling assembly of
FIG. 19 in a second position embedded in a concrete slab in an
initial positon seated in a roadbed.
FIG. 23 is a sectional view of a lifting and leveling assembly
embedded in a concrete slab in an initial positon seated in a
roadbed according a third embodiment of the invention.
FIG. 24A is a sectional view of the lifting and leveling assembly
of FIG. 23 embedded in a concrete slab in a lifting position.
FIG. 24B is a sectional view of the lifting and leveling assembly
of FIG. 23 embedded in a concrete slab in a leveling position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings and in particular to FIGS. 1 and 2,
there is shown an exploded view and a sectional view of a lifting
and leveling assembly 100 respectively according to an embodiment
of the invention. The leveling and lifting assembly 100 comprises a
rectangular leveling plate 110, an anchoring assembly 120, a thread
protecting sleeve 130, an axially supported lifting bolt 140 and an
end cap 150.
The rectangular lifting plate 110 comprises hollow cylinder 114
welded to a base plate 112. The base plate 112 and hollow cylinder
114 may be made from high strength steel and dimensioned to
compliment the slab thickness.
The anchoring assembly 120 comprises a threaded sleeve in the form
of a threaded hex nut 124 affixed to a rectangular anchor plate 122
having a circular through hole 128 coaxially aligned with the
threaded hex nut 124 having a threaded through hole 126. The
anchoring assembly 120 provides a bearing surface to axially
support the axially supported lifting bolt 140. The threaded hex
nut 124 and rectangular anchor plate 122 may be made from high
strength steel and dimensioned to compliment the slab
thickness.
The thread protecting sleeve 130 comprises a hollow cylinder 136
with a circular base 132 having a circular through hole 134. The
hollow cylinder 136 and circular base 132 may be integrally formed
from high strength steel or welded together from separate pieces or
made from high strength thermoset plastics or thermoplastics and
may be and dimensioned to compliment the slab thickness.
The axially supported lifting bolt 140 comprises a threaded shaft
142, threaded collar 144 and a hexagon socket head 146 having a
square recess 148. An angled surface 149 is formed between the
hexagon socket head 146 and threaded shaft 142. Alternatively, the
connection between the hexagon socket head 146 and threaded shaft
142 may form a horizontal surface (not shown). The portion of the
threaded shaft beneath the hexagon socket head 146 may be
unthreaded and the threaded collar 144 may abut the unthreaded
portion. The axially supported lifting bolt 140 may be made from
high strength steel by methods well known in the art and
dimensioned to compliment the slab thickness. The hexagon socket
head 146 and square recess 148 may be dimensioned to compliment a
variety of socket wrenches and square drivers respectively.
The end cap 150 comprises head engaging boss 152 and protrusions
154. The end cap 150 may be made from thermoset plastics or
thermoplastics and may be formed by through methods well known in
the art such as injection molding.
The rectangular leveling plate 110, anchoring assembly 120, thread
protecting sleeve 130, axially supported lifting bolt 140 and end
cap 150 are all coaxially aligned such that the axially supported
lifting bolt 140 passes through the thread protecting sleeve 130,
anchoring assembly 120 and abuts rectangular leveling plate 110
with the end cap 150 disposed on top of the axially supported
lifting bolt 140, best shown in FIG. 3. The assembly rests on the
rectangular leveling plate 110 with the bottom surface of the
anchor plate 122 abutting the top surface of the hollow cylinder
114. The circular base 132 of the thread protecting sleeve 130
abuts the top surface of the threaded hex nut 124. The threaded
shaft 142 passes through the circular through hole 134, threads
through the threaded hex nut 124, passes through the circular
through hole 128 and into the hollow cylinder 114 until abutting
the top surface of the base plate 112. The threaded collar 144 is
disposed in surrounding contact with the threaded shaft 142 beneath
the angled surface 149 abutting the unthreaded portion of the
threaded shaft 142 such that the outside vertical surface is in
communication with the inside surface of the hollow cylinder 136 to
provide a bearing surface to axially support the axially supported
lifting bolt 140. A portion of the vertical outside walls of the
end cap 150 are also in communication with the inside surface of
the hollow cylinder 136 and the head engaging boss 152 encompasses
the hexagon socket head 146 so as to secure the end cap 150 to the
hexagon socket head 146.
Referring now to FIG. 3, there is shown a flowchart of method 200
of making and installing a precast concrete slab using a lifting
and leveling assembly according to an embodiment of the invention.
A precast concrete slab using a leveling and lifting assembly 100
according to an embodiment of the invention first undergoes a
casting step 210 wherein one or more leveling and lifting
assemblies 100 are placed into a slab mold wherein the lower
surface of the leveling plate is positioned on a bottom surface of
the mold and the upper end cap fits against the lower surface of
the upper half of the mold. Cement is then poured into the mold and
the cement is cured, thus embedding the leveling and lifting
assemblies 100 into the concrete slab. Typically at least four of
the leveling and lifting assemblies 100 are embedded into the slab,
one at each corner. After casting and curing, a first lifting step
220 lifts the slab for placement into storage or onto
transportation using the lifting and leveling assembly 100.
Utilizing the lifting and leveling assembly, a stacking step 230
may be performed wherein multiple precast concrete slabs are
stacked on top of one another. Once at the installation site, a
second lifting step 240 lifts the slab for placement into an
excavation or road bed using the lifting and leveling assembly 100.
A leveling step 250 uses the lifting and leveling assembly 100 to
raise the precast concrete slab so as to be level with adjacent
slabs. Once leveled, a grouting step 260 is performed to pump grout
into the voids on top of and beneath the slab.
FIG. 4 shows the lifting and leveling assembly 100 in the casting
position embedded in a precast concrete slab 310. The lifting and
leveling assembly 100 is positioned so that the bottom surface of
the base plate 112 is flush with the bottom surface of the precast
concrete slab 310 and the top surface of the end cap 150 is
substantially flush with the top surface of the precast concrete
slab 310. The rectangular leveling plate 110, anchoring assembly
120, thread protecting sleeve 130 and end cap 150 encompass the
axially supported lifting bolt 140 so as to prevent concrete from
contacting the axially supported lifting bolt 140 during
casting.
FIG. 5 shows a lifting and leveling assembly 600 in the casting
position embedded in a precast concrete slab 310 according to a
modified form of the invention. The lifting and leveling assembly
600 may comprise a hollow cylinder 614 welded to a curved base
plate 612. The perimeter of the curved base plate 612 is curved
upwards towards the hollow cylinder 614 forming a concavo-convex
shape. A leakage preventing material 616 such as plastic tape, foam
tape or the like may be positioned on the convex side of the curved
base plate 612 at the perimeter so as to prevent the precast
concrete slab 310 from flowing beneath the curved base plate 612.
The leakage preventing material 616 may be removed after the
precast concrete slab 310 is cured and removed from the mold.
FIG. 6 shows the lifting and leveling assembly 100 in the precast
concrete slab 310 with the axially supported lifting bolt 140 in
the lifting position. The end cap 150 is removed exposing the
hexagon socket head 146 and the square recess 148. The axially
supported lifting bolt 140 is rotated counter clockwise indicated
by arrows 510 until the top surface of the threaded collar 144 is
flush with the top surface of the precast concrete slab 310.
Rotation of the axially supported lifting bolt 140 can achieved
using a conventional hex socket wrench which mates with the hexagon
socket head 146 or a conventional square driver which mates with
the square recess 148. When rotated, the threaded shaft 142 in
rotatable engagement with anchoring assembly 120 also rotates,
moving the axially supported lifting bolt 140 away from the
rectangular leveling plate 110. The anchoring assembly 120 is
anchored in the precast concrete slab 310 ad thus does not rotate
or move with the bolt 140. During rotation, the outside surface of
the threaded collar 144 bears against either the thread protecting
sleeve 130 or the precast concrete slab 310 so that any radial
forces applied to the axially supported lifting bolt 140 are
directed into precast concrete slab 310 so as not to deform the
threaded bolt 142.
With the hexogen socket head 146 exposed, a conventional lifting
eye 710 may be secured to the hexagon socket head 146 as shown in
FIG. 8. The conventional lifting eye 710 may be any commercially
available lifting eye similar in construction and operation to U.S.
Pat. No. 4,703,595. A crane (not shown) may then attach to the
lifting eye 710 using a rigging system (not shown) to lift the
precast concrete slab 310. It will be understood that common
precast concrete slabs are rectangular in shape and to lift
properly, a lifting and leveling assembly 100 may be disposed at
each corner of the precast concrete slab 310 so as to properly
distribute the load during lifting.
To save space during storage or transportation, the lifting and
leveling assembly 100 may facilitate the stacking of precast
concrete slabs 310 as shown in FIG. 9. The end cap 150 may be
reinstalled over the hexagon socket head 146 with the axially
supported lifting bolt 140 still in the lifting position shown in
FIG. 8. Another precast concrete slab 310 with or without an
embedded lifting and leveling assembly 100 may be place on top of
the end cap 150 so as to create a gap 810 between the top surface
and bottom surface of the precast concrete slabs 310. The gap 810
may enable the forks of a fork lift to fit between the two precast
concrete slabs 310 so that the fork truck may lift and transport
the precast concrete slabs 310. The end cap 150 acts as a bearing
pad so as to protect the hexagon socket head 146. Alternatively,
the end cap 150 may be omitted and the precast concrete slab may be
placed directly on top of the hexagon socket head 146.
To install the precast concrete slab 310 in an excavation, the
precast concrete slab is lifted as shown and described in FIGS. 6
and 7 and positioned in the excavation or road bed. Once positioned
in the excavation, the precast concrete can be raised and leveled
as shown in FIG. 9. Using a hex socket wrench which mates with the
hexagon socket head 146 or a square driver which mates with the
square recess 148, the axially supported lifting bolt 140 may be
rotated clockwise as indicated by arrows 910 driving the axially
supported lifting bolt 140 toward the rectangular leveling plate
110 so that the bottom surface of the threaded bolt 142 contacts
the top surface of the base plate 112. Continued rotation of the
axially supported lifting bolt 140 raises the slab and separates
the rectangular leveling plate 110 from the anchoring assembly 120.
The anchoring assembly 120 in mating engagement with the threaded
bolt 142 acts as a axial guide for the axially supported lifting
bolt 140 and directs upward reaction force exerted by the
excavation bed 920 into the precast concrete slab 310 raising the
precast concrete slab 310. In this way the level of the precast
concrete slab 310 relative to the excavation bed 920 can be
adjusted so as to be level with adjacent slabs. It will be
understood that common precast concrete slabs are rectangular in
shape and to level properly, a lifting an leveling assembly 100 may
be disposed at or near each corner of the precast concrete slab 310
so as to raise and level each corner of the precast concrete slab
310. It will also be understood that an excavation bed 920 may be
any surface on which the precast concrete slab 310 is to be placed
upon.
FIG. 10 shows the lifting and leveling assembly 600 in the leveling
position with a rectangular leveling plate 610 having a curved base
plate 612 positioned in an excavation bed 920 to raise and level a
precast concrete slab 310 according to another embodiment. The
curved perimeter of the curved base plate 612 protects any material
coating or covering the excavation bed 920 in the event of any
lateral movement of the precast concrete slab 310 and lifting and
leveling assembly 600. The curved edges eliminate any sharp edges
contacting the excavation bed 920 which may puncture or damage a
material coating or covering the excavation bed 920. The curved
edges also facilitate lateral movement of the precast concrete slab
310 by eliminating sharp edges contacting the excavation bed 920
which may cause a plow effect and hinder lateral movement.
Once the desired level is achieved, a suitable grout 1010 may be
pumped on top and beneath the precast concrete slab 310 to fill and
solidify the void between the excavation bed 920 and the precast
concrete slab 310 and the void between the threaded collar 144 and
the top surface of the precast concrete slab 310 as shown in FIG.
11. Alternatively, the end cap 150 may be reinstalled on the
axially supported lifting bolt 1140 and grout may fill the void
between the top surface of the end cap 150 and the top surface of
the precast concrete slab 310 as illustrated in FIG. 12.
Now referring to FIG. 13 and FIG. 14, in a another embodiment of
the invention where like elements from the leveling lifting
assembly 100 shown in FIGS. 1-12 are identified with the same
reference numeral increased by 1000, a lifting and leveling
assembly 1100 includes an outer housing 1160. The outer housing
1160 comprises a cylindrical cover sleeve 1162, anchor plate
retainers 1164 and a base plate cover 1166. The end cap 1150,
thread protection sleeve 1130 and outer housing 1160 are configured
to communicate with one another to sheath and retain the interior
components of the lifting and leveling assembly 1100. The thread
protecting sleeve 1130 is slidably received in an upper portion of
the outer housing 1160 and the end cap 1150 is slidably received in
the upper portion of the thread protecting sleeve 1130. The outer
housing 1160 may be made from thermoset plastics or thermoplastics
and may be formed by through methods well known in the art such as
injection molding.
The cylindrical sleeve 1162 comprises a height adjustment track
1161 and height locking recesses 1163 A-C. The thread protection
sleeve 1130 is configured to be adjustably retained within the
cylindrical sleeve 1162 and includes a locking protrusion 1135 at
the lower end which rides inside the height adjustment track. By
vertically adjusting the height of the thread protecting sleeve
1130 relative the cylindrical sleeve 1162 in a telescoping fashion,
the locking protrusion 1135 may be aligned with and retained by one
of the height locking recesses 1163 A-C. In this way, the overall
height of the lifting and leveling assembly 1100, defined by the
height between the base plate 1112 and the top surface of the end
cap 1150 may be adjusted so as to accommodate concrete slabs having
different thicknesses.
The outer housing 1160 may be formed by two interconnecting housing
halves 1160A, 1160B attached together along vertical seam 1165 by
corresponding male connectors and female connectors along the
vertical 1165 seam. The male connectors may be spring clips 1165
and the female connectors may be apertures 1169 corresponding to
the spring clips 1167 as illustrated. The two piece design allows
the outer housing 1160 to be easily assembled around the anchoring
assembly 1120 and anchor plate 1122 such that the anchor plate 1122
extends through a gap 1171 formed in the outer housing 1160 between
the anchor plate retainers 1164. It will be understood that the two
interconnecting housing halves 1160A, 1160B may be attached
together by any attachment means well known in the art including
but not limited to clips, snaps, nails, screws, bolts, adhesives,
welds or rivets.
Referring now to FIG. 15, the anchoring assembly 1120 comprises a
threaded sleeve 1125 and an anchor plate 1122 attached to the
threaded sleeve 1125 and extending transversely therefrom such that
the threaded sleeve 1125 is disposed above and below the anchor
plate 1122. The anchor plate 1122 may extend 360.degree. around the
threaded sleeve 1125. Alternatively, outwardly extending rebar
attached to the threaded sleeve 1125 may be used with or in lieu of
the anchor plate 1122. The base plate 1112, anchoring assembly
1120, thread protecting sleeve 1130, axially supported lifting bolt
1140 and end cap 1150 are all coaxially aligned such that the
axially supported lifting bolt 1140 passes through the thread
protecting sleeve 1130 and anchoring assembly 1120. The anchoring
assembly 1120 rests on the base plate 1112 with the bottom surface
of the threaded sleeve 1125 abutting the top surface of the base
plate 1112. The outer housing 1160 surrounds at least a portion of
the axially supported lifting bolt 1140, the threaded sleeve 1125
and base plate 1112 to prevent concrete from contacting the axially
supported lifting bolt 1140.
The base plate cover 1166 comprises downwardly extending legs 1168.
The downwardly extending legs 1168 selectively retain the base
plate 1112 within the base plate cover 1166. The legs 1168 may be
dimensioned such that the friction force between the legs 1168 and
side surfaces of the base plate 1112 retains the base plate 1112
within the base plate cover 1166 absent of any axially supported
lifting bolt 1140 induced force. When a force is exerted on the top
surface of the base plate 1112 by the axially supported lifting
bolt 1140 being threaded further into the anchor assembly 1120, the
force exerted on the base plate 1112 over comes the friction force,
allowing the base plate 1112 to move downwards and away from the
base plate cover 1166.
FIG. 16 shows the lifting and leveling assembly 1100 with the
thread protecting sleeve 1130 positioned to achieve a lower overall
height of the lifting and leveling assembly 1100 and an axially
supported lifting bolt 1140 having a length corresponding to the
lower height. The thread protecting sleeve 1130 is moved downward
within the cylindrical sleeve 1162 of the outer housing 1160 in a
telescoping fashion. The thread protecting sleeve 1130 may be moved
downward until the abutting the anchor plate 1122 as illustrated or
to an intermediate height where it may be retained in the desired
position by the locking recesses 1163 A-C (FIG. 15) as described
above. The axially supported lifting bolt 1140 provided may also
correspond to any of the intermediate heights. It will be
understood that the thread protecting sleeve 1130 may be adjusted
to realize a lifting and leveling assembly 1100 having a variety of
predetermined heights which may correspond to standard thickness of
precast concrete slabs. For example, the lifting and leveling
assembly 1100 may be adjustable to achieve overall heights in the
range of 7'' to 13''.
FIG. 17 shows the lifting and leveling assembly 1100 in the casting
position embedded in a precast concrete slab 310 and positioned on
an excavation bed 920. The lifting and leveling assembly 1100 is
positioned so that the bottom surface of the legs 1168 are flush
with the bottom surface of the precast concrete slab 310 and the
top surface of the end cap 150 is substantially flush with the top
surface of the precast concrete slab 310. The anchoring assembly
1120, thread protecting sleeve 1130, end cap 150 and outer housing
1160 encompass the axially supported lifting bolt 140 so as to
prevent concrete from contacting the axially supported lifting bolt
1140, the threaded collar 1144, threaded sleeve 1125 and the base
plate 1112 during casting.
To install the precast concrete slab 310 in an excavation, the
precast concrete slab is lifted as shown and described in FIGS. 6
and 7 and positioned in the excavation bed 920. Once positioned in
the excavation, the precast concrete can be raised and leveled as
shown in FIG. 18. Using a hex socket wrench which mates with the
hexagon socket head 1146 or a square driver which mates with the
square recess 1148, the axially supported lifting bolt 1140 may be
rotated clockwise as indicated by arrows 910 driving the axially
supported lifting bolt 1140 toward the base plate 1112 so that the
bottom surface of the axially supported lifting bolt 1140 contacts
the top surface of the base plate 1112. Continued rotation of the
axially supported lifting bolt 1140 causes the base plate 1112 to
be separate from bottom surface of the anchoring sleeve 1125 of the
anchoring assembly 1120 and exert a downward force on the
excavation bed 920. The anchoring assembly 1120 in mating
engagement with the axially supported lifting bolt 1140 acts as a
axial guide for the axially supported lifting bolt 1140 and directs
upward reaction force exerted by the excavation bed 920 into the
precast concrete slab 310 causing the precast concrete slab 310 to
be raised. As the precast concrete slab 310 is raised, the base
plate 1112 separates from the base plate cover 1166. Because the
base plate cover 1166 shields the base plate 1112 from the
concrete, there is no adhesion between the base plate 1112 and the
precast concrete slab 310 that may prevent the base plate 1112 from
being separated from the anchoring assembly 1120. In this way, the
level of the precast concrete slab 310 relative to the excavation
bed 920 can be adjusted so as to be level with adjacent slabs. It
will be understood that common precast concrete slabs are
rectangular in shape and to level properly, a lifting an leveling
assembly 1100 may be disposed at each corner of the precast
concrete slab 310 so as to raise and level each corner of the
precast concrete slab 310. It will also be understood that an
excavation bed 920 may be any surface on which the precast concrete
slab 310 is to be placed upon.
Once the desired level is achieved, a suitable grout may be pumped
beneath the precast concrete slab 310 from separate fill holes to
fill and solidify the void between the excavation bed 920 and the
precast concrete slab 310. In addition, the void between the
threaded collar 1144 and the top surface of the precast concrete
slab 310 can be filled as well with grout as described above and
shown in FIG. 11. The end cap may also be reinstalled prior to
pumping grout so that the grout fills the void between the top
surface of the end cap and the top surface of the precast concrete
slab 310 as described above and shown in FIG. 12. To reuse the
lifting and leveling assembly 1100, the grout above the end cap may
be drilled out and the end cap removed to expose the axially
supported lifting bolt 1140.
Now referring to FIG. 19, in a another embodiment of the invention
where like elements from the leveling lifting assembly 100 shown in
FIGS. 13-18 are identified with the same reference numeral
increased by 2000 and where like elements from the leveling lifting
assembly 1100 shown in FIGS. 13-18 are identified with the same
reference numeral increased by 1000, a lifting and leveling
assembly 2100 includes a thread protecting sleeve 2130 attached to
an anchoring assembly 2120. The thread protecting sleeve 2130
comprises an upper hollow cylinder 2136 with a circular base 2132
having a circular through hole 2134 and a lower hollow cylinder
2133 extending downwardly from the circular base 2132 about the
perimeter of the circular through hole 2134. The lower hollow
cylinder 2133 comprises a pair of slots 2135 configured to allow
the lower hollow cylinder 2133 to flex radially and a snap ring
2137 disposed on the inner surface of the lower hollow cylinder
2133, protruding inwardly therefrom.
The anchoring assembly 2120 comprises a threaded sleeve having an
upper threaded portion 2125A and a lower threaded portion 2125B and
an anchor plate 2122 disposed between the threaded portions 2125A,
B and extending laterally therefrom. Both the threaded portions
comprise annular grooves 2127 A, B disposed on the outer surface
thereof.
The lifting and leveling assembly 2100 also comprises a base plate
cover 2166 configured to selectively retain the base plate 2112
within the base plate cover 2166 as described in the second
embodiment. The base plate cover 2166 comprises an upstanding
cylinder 2173 extending upwardly from the top surface of the base
plate cover 2166. The upstanding cylinder 2173 comprises a pair of
slot 2175 configured to allow the upstanding sleeve 2133 to flex
radially and a snap ring 2177 disposed on the inner surface of the
upstanding cylinder 2173, protruding inwardly therefrom.
The snap ring 2137 of the lower hollow cylinder 2133 is configured
to be received within one of the annular grooves 2127A on the upper
portion 2125A of the anchoring assembly 2120 to affix the thread
protecting sleeve 2130 to the anchoring assembly 2120. The snap
ring 2177 of the base plate cover 2166 is configured to be received
within one of the annular grooves 2127B on the lower portion 2125B
of the anchoring assembly 2120 to affix the base plate cover 2166
to the anchoring assembly 2120.
When lifting and leveling assembly 2100 is assembled, the base
plate 2112 is selectively retained in the base plate cover 2166,
the base plate cover 2166 and thread protecting sleeve are affixed
to the anchoring assembly 2120, the axially supported lifting bolt
2140 is rotatably received within the thread protection sleeve
2130, anchoring assembly 2120 and the base plate cover 2166 until
in contact with the base plate 2112 and the end cap 2150 is
slidably received within the upper hollow cylinder 2136 of the
thread protection sleeve 2130 and is disposed above and around the
axially supported lifting bolt 2140. In this way, all of the
elements of the lifting and leveling assembly 2100 form an
assembled package with no loose parts. The thread protecting sleeve
2130 and base plate cover 2166 may be made from thermoset plastics
or thermoplastics and may be formed by through methods well known
in the art such as injection molding.
FIG. 20 shows another embodiment of a thread protecting sleeve 3130
to be used with the lifting and leveling assembly 2100 shown in
FIG. 19. The thread protecting sleeve 3130 is formed by two
interconnecting sleeve halves 1160A, 1160B attached together along
a vertical seam by corresponding male connectors and female
connectors along the vertical seam. The male connectors may be
spring clips 3167 and the female connectors may be apertures 3169
corresponding to the spring clips 3167 as illustrated. The two
piece design allows the thread protecting sleeve 3130 to be easily
assembled around the anchoring assembly 2120 shown in FIG. 19. It
will be understood that the two interconnecting sleeve halves
3130A, 3160B may be attached together by any attachment means well
known in the art including but not limited to clips, snaps, nails,
screws, bolts, adhesives, welds or rivets.
FIGS. 21 and 22 show the lifting and leveling assembly 2100 in the
casting position embedded in a precast concrete slab 310 and
positioned on an excavation bed 920 wherein the precast concrete
slab 310 in FIG. 21 has a thickness T1 and the precast concrete
slab 310 in FIG. 22 has a thickness T2 which is larger than T1. The
lifting and leveling assembly 2100 is positioned so that the bottom
surface of the base plate 2122 is flush with the bottom surface of
the precast concrete slab 310 and the top surface of the end cap
150 is substantially flush with the top surface of the precast
concrete slab 310. The anchoring assembly 2120, thread protecting
sleeve 2130, end cap 150 and base plate cover 2160 encompass the
axially supported lifting bolt 2140 so as to prevent concrete from
contacting the axially supported lifting bolt 2140, the threaded
collar 2144, threaded sleeve 2125 and the base plate 2112 during
casting.
To accommodate the larger thickness T2 of the precast concrete slab
310 in FIG. 22, the overall height of the lifting and leveling
assembly 2100 may be adjusted in two ways. First, the snap ring
2137 on the lower hollow cylinder 2133 received in the lower most
annular groove 2125A as shown in FIG. 21 may be removed and
received in the upper most annular groove 2125A as shown in FIG.
21. In this way a gap A is formed between the anchor plate 2122 and
the lower portion of the lower hollow cylinder 2133, thereby
raising the height of the thread protection sleeve 2130. Second,
the axially supported lifting bolt 2140 may be rotated so as to
form a gap B between the base plate 2112 and the bottom of the
axially supported lifting bolt 2140. The end cap 2150 may also
slide upwards within the thread protection sleeve 2130 a distance C
that corresponds to the gap B. In this way the overall height of
the lifting and leveling assembly 2100 may be adjusted at infinite
intervals so long as the axially supported lifting bolt 2140 is
received within the anchoring assembly 2120 and the end cap 2150 is
received within the thread protecting sleeve 2030.
To install the precast concrete slab 310 in an excavation, the
precast concrete slab is lifted as shown and described in FIGS. 6
and 7 and positioned in the excavation bed 920. Once positioned in
the excavation, the precast concrete slab 310 can be raised and
leveled as shown and described in FIG. 18.
Once the desired level is achieved, a suitable grout may be pumped
beneath the precast concrete slab 310 from separate fill holes to
fill and solidify the void between the excavation bed 920 and the
precast concrete slab 310. In addition, the void between the
threaded collar 2144 and the top surface of the precast concrete
slab 310 can be filled as well with grout as described above and
shown in FIG. 11. The end cap 2150 may also be reinstalled prior to
pumping grout so that the grout fills the void between the top
surface of the end cap and the top surface of the precast concrete
slab 310 as described above and shown in FIG. 12. To reuse the
lifting and leveling assembly 2100, the grout above the end cap may
be drilled out and the end cap 2150 removed to expose the axially
supported lifting bolt 2140.
Now referring to FIG. 23, in a another embodiment of the invention
where like elements from the leveling lifting assembly 2100 shown
in FIGS. 19, 21 and 22 are identified with the same reference
numeral increased by 2000, a lifting and leveling assembly 4100
includes a thread protecting sleeve 2130 having a consistent inner
diameter D. The thread protecting sleeve 2130 comprises a snap ring
4137 disposed on the inner surface thereof and protruding inwardly
therefrom to be received within the annular grooves 4127A on the
anchoring assembly 4120 in order to affix the thread protection
sleeve 4130 to the anchoring assembly 4120. As shown in the casting
position embedded in a precast concrete slab 310 and positioned on
an excavation bed 920, the lifting and leveling assembly 4100 is
configured to be cast without an axially supported lifting
bolt.
To lift the precast concrete slab 310, the end cap 4150 may be
removed and an axially supported lifting bolt 4140 may be inserted
through the thread protecting sleeve 4130 and into the anchoring
assembly 4120 until the lower surface of the threaded collar 4144
abuts the top surface of the precast concrete slab 310 as shown in
FIG. 24A. With the hexogen socket head 4146 exposed, a conventional
lifting eye 710 may be secured to the hexagon socket head 4146. The
conventional lifting eye 710 may be any commercially available
lifting eye similar in construction and operation to U.S. Pat. No.
4,703,595. A crane (not shown) may then attach to the lifting eye
710 using a rigging system (not shown) to lift the precast concrete
slab 310. It will be understood that common precast concrete slabs
are rectangular in shape and to lift properly, a lifting and
leveling assembly 4100 may be disposed at each corner of the
precast concrete slab 310 so as to properly distribute the load
during lifting.
Once positioned in the excavation, the precast concrete slab 310
can be raised and leveled by inserting a lifting bolt 5180 through
the thread protecting sleeve 4130 and into the anchoring assembly
4120. With the lifting bolt 5180 inserted, the precast concrete
slab 310 can be raised and leveled as shown and described in FIG.
18.
Once the desired level is achieved, a suitable grout may be pumped
beneath the precast concrete slab 310 from separate fill holes to
fill and solidify the void between the excavation bed 920 and the
precast concrete slab 310. Once the grout is cured, the lifting
bolt 5180 may be removed and the void within the thread protecting
sleeve 4130 and anchoring assembly 4120 can be filled with
grout.
The lifting and leveling assembly according to this invention has
the ability to improve user usability, reduce labor costs, increase
efficiency and improve safety. The lifting and leveling assembly
incorporates the lifting bolt and end cap with the rest of the
assembly, reducing the possibility for missing parts needed for
installation and use. This also allows the lifting and leveling
assembly to be used to lift and level a precast concrete slab
without the removal of the lifting bolt, saving significant time.
Furthermore, the lifting bolt top of the lifting bolt is disposed
beneath the surface of the concrete slab during leveling so that
the lifting bolt does not present a tripping hazard and so that the
lifting bolt does not need to be removed after grouting. The
lifting and leveling assembly also has reusable reuse by removing
the grout disposed above the threaded collar or end cap. The
lifting bolt is designed to work with commercially available
pivoting lifting eyes which enable fast installation in one fluid
step. The lifting and leveling assembly has a system that requires
only a simple rotation of a bolt using conventional tools to level
or ready the slab for lifting. The outer housing surrounding the
base plate prevents adhesion between the precast concrete slab and
the base plate, which facilitates separation of the base plate from
the precast concrete slab to aid in leveling. Furthermore, the
outer housing and adjustable thread protecting sleeve allows the
use of the same lifting and leveling assembly for precast concrete
slabs of different heights by adjusting the height of the lifting
and leveling device and supplying an axially supported lifting bolt
having a corresponding height.
While the invention has been specifically described in connection
with certain specific embodiments thereof, it is to be understood
that this is by way of illustration and not of limitation.
Reasonable variation and modification are possible within the scope
of the forgoing disclosure and drawings without departing from the
spirit of the invention which is defined in the appended
claims.
* * * * *