U.S. patent application number 11/621596 was filed with the patent office on 2007-08-02 for reinforcing bar splice with threaded collars.
Invention is credited to Paul B. Allen, Louis J. Colarusso, Ward M. Judson, Dieter Russwurm.
Application Number | 20070175167 11/621596 |
Document ID | / |
Family ID | 38103098 |
Filed Date | 2007-08-02 |
United States Patent
Application |
20070175167 |
Kind Code |
A1 |
Allen; Paul B. ; et
al. |
August 2, 2007 |
REINFORCING BAR SPLICE WITH THREADED COLLARS
Abstract
A reinforcing bar splice secures together reinforcing bar ends
by utilizing, at both ends, both tapered-thread coupling and
coupling involving a filler, such as a grout or an epoxy. The
splice may include a central tapered-thread central sleeve or
coupler, and a pair of collars that are screwed onto
externally-threaded ends of the central sleeve. The central sleeve
has a channel therethrough with tapered internal threads at both
ends, and a center internal relief. The internal relief is an
increased radius center portion that ensures full thread contact
between the tapered internal threads and external threaded sections
of the rebar ends. The sleeve has externally-threaded ends that are
engaged by internally-threaded ends of a pair of collars. Distal to
their internally-threaded ends, the collars have
filler-material-receiving channels. The channels include plural
sloped surfaces for aiding in securing filler material between the
collars and the rebar ends.
Inventors: |
Allen; Paul B.; (Medina,
OH) ; Colarusso; Louis J.; (Macedonia, OH) ;
Russwurm; Dieter; (Langenargen, DE) ; Judson; Ward
M.; (Hudson, OH) |
Correspondence
Address: |
Jonathan A. Platt;Renner, Otto, Boisselle & Sklar, LLP
19th Floor, 1621 Euclid Ave.
Cleveland
OH
44115
US
|
Family ID: |
38103098 |
Appl. No.: |
11/621596 |
Filed: |
January 10, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60758687 |
Jan 13, 2006 |
|
|
|
Current U.S.
Class: |
403/307 |
Current CPC
Class: |
Y10T 403/5746 20150115;
E04C 5/165 20130101 |
Class at
Publication: |
52/726.1 |
International
Class: |
E04C 3/30 20060101
E04C003/30 |
Claims
1. A reinforcing bar splice comprising: a sleeve having sleeve
internal tapered threads at opposite sleeve ends; and a pair of
collars mechanically coupled to the ends, and extending axially
beyond the sleeve ends.
2. The splice of claim 1, wherein the collars have collar internal
threads at distal collar ends that threadedly engage sleeve
external threads at the sleeve ends.
3. The splice of claim 2, wherein the collars have respective
channels at proximal ends that have diameters greater than maximum
diameters of tapered-thread portions of the sleeve.
4. The splice of claim 3, further comprising filler material in the
channels.
5. The splice of claim 4, wherein the filler material includes an
epoxy.
6. The splice of claim 4, wherein the filler material includes a
grout.
7. The splice of claim 3, wherein each of the channels has plural
sloped inner surfaces, wherein the sloped inner surfaces have a
smaller diameter closer to the distal end of the collar.
8. The splice of claim 1, wherein the sleeve has a through-hole;
and wherein the sleeve internal tapered threads are at
tapered-thread portions at opposite ends of the through-hole.
9. The splice of claim 1, wherein the sleeve has an internal relief
at a central portion of the through-hole.
10. The splice of claim 1, in combination with a pair of rebar
ends; wherein the rebar ends have external tapered thread portions
threadedly engaged with the internal tapered threads of the
sleeve.
11. The combination of claim 10, further comprising filler material
in spaces between the collars and respective of the rebar ends.
12. The combination of claim 11, wherein the filler material
includes one or more of an epoxy and a grout.
13. The combination of claim 12, wherein the collars have collar
internal threads at distal collar ends that threadedly engage
sleeve external threads at the sleeve ends.
14. The combination of claim 13, wherein each of the channels has
plural sloped inner surfaces, wherein the sloped inner surfaces
have a smaller diameter closer to the distal end of the collar.
15. The combination of claim 14, wherein tensile stresses on the
rebar ends is converted at least in part to compressive stresses in
the filler material, which in turn is converted at least in part to
hoop stresses in the collars.
16. The splice of claim 15, wherein the sleeve has a through-hole;
and wherein the sleeve internal tapered threads are at
tapered-thread portions at opposite ends of the through-hole.
17. The splice of claim 16, wherein the sleeve has an internal
relief at a central portion of the through-hole.
18. A method of coupling reinforcing bar ends, the method
comprising: securing external tapered thread portions of the
reinforcing bar ends in opposite internal tapered thread ends of a
sleeve; and placing filler material between the reinforcing bar
ends and collars that are mechanically coupled to the sleeve.
19. The method of claim 18, wherein the filler material includes at
least one of an epoxy and a grout.
Description
[0001] This application claims priority under 35 USC 119 to U.S.
Provisional Application No. 60/758,687, filed Jan. 13, 2006.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field of the Invention
[0003] This invention relates generally to reinforcing bar
splices.
[0004] 2. Description of the Related Art
[0005] High tensile strength splices for reinforcing bar used in
concrete construction have been widely employed. One type using a
sleeve with internal deformations employs as a locking element
filler metal formed from an exothermic reaction, such molten metal
entering the sleeve through a tap hole. When the metal solidifies
it forms a lock between the deformation on the interior of the
sleeve, and the typical deformations found on the exterior of the
reinforcing bar. These types of splices are sold by ERICO Inc. of
Solon, Ohio, under the trademark CADWELD.RTM.. Examples of such
splices may be seen in prior U.S. Pat. Nos. 3,234,603 and
3,255,498, to Leuthy et al.
[0006] Another type of reinforcing bar splice that is widely
employed is a threaded splice connection. A sleeve with internal
threads is threaded into a bar with external threads. One such
system which is widely employed and frequently specified is a taper
thread system such as that made and sold by ERICO Inc. of Solon,
Ohio under the trademark LENTON.RTM..
[0007] Another type of splice is a grout splice system, such as
that shown in Yee, U.S. Pat. Nos. 3,540,763 and 4,672,212. These
patents use a sleeve with internal deformations and a volume stable
grout to form a locking element within the sleeve locking on the
internal deformations of the bar, much like the metal of the
earlier Leuthy patents.
[0008] All of these methods have their advantages and
disadvantages, and none is ideal for all situations. Therefore
there is room for improvement in the area of reinforcing bar
splices.
SUMMARY OF THE INVENTION
[0009] According to an aspect of the invention, a reinforcing bar
splice includes: an internally threaded sleeve, and a pair of
internally threaded collars that engage externally threaded ends of
the sleeve. The collars have openings that are configured for
receiving reinforcing bar ends, and securing the bar ends
therewithin using an epoxy or grout.
[0010] According to another aspect of the invention, a reinforcing
bar splice includes an internally threaded section for threadedly
engaging tapered thread ends of reinforcing bars, and wider
sections at distal ends of the splice, for engaging the reinforcing
bars with a grout or epoxy. The wider sections may have ramped or
sloped surfaces for improving the holding of the grout or
epoxy.
[0011] According to yet another aspect of the invention, an
internally tapered threaded reinforcing bar splice has a central
relief therein. The central relief relieves thread stress
concentrations, which may help retard fatigue crack initiation.
[0012] According to still another aspect of the invention, a
reinforcing bar splice engages each of a pair of reinforcing bar
ends with both tapered threads and an epoxy or grout.
[0013] According to a further aspect of the invention, a tapered
thread reinforcing bar splice achieves improved fatigue performance
by transferring some of the load from a tapered thread portion of
the splice to an epoxy- or grout-filled portion of the splice.
[0014] According to another aspect of the invention, a reinforcing
bar splice includes: a sleeve having sleeve internal tapered
threads at opposite sleeve ends; and a pair of collars mechanically
coupled to the ends, and extending axially beyond the sleeve
ends.
[0015] According to yet another aspect of the invention, a method
of coupling reinforcing bar ends, includes the steps of: securing
in external tapered thread portions of the reinforcing bar ends in
opposite internal tapered thread ends of a sleeve; and placing
filler material between the reinforcing bar ends and collars that
are mechanically coupled to the sleeve. The filler material may
include a grout and/or an epoxy.
[0016] To the accomplishment of the foregoing and related ends, the
invention comprises the features hereinafter fully described and
particularly pointed out in the claims. The following description
and the annexed drawings set forth in detail certain illustrative
embodiments of the invention. These embodiments are indicative,
however, of but a few of the various ways in which the principles
of the invention may be employed. Other objects, advantages and
novel features of the invention will become apparent from the
following detailed description of the invention when considered in
conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In the annexed drawings, which are not necessarily to
scale:
[0018] FIG. 1 is an oblique view of a reinforcing bar splice of the
present invention, coupling together reinforcing bar ends;
[0019] FIG. 2 is an exploded view of the splice of the present
invention;
[0020] FIG. 3 is an exploded, sectional side view of the splice of
FIG. 1; and
[0021] FIG. 4 is a sectional side view of the splice of FIG. 1.
DETAILED DESCRIPTION
[0022] A reinforcing bar splice secures together reinforcing bar
ends by utilizing, at both ends, both tapered-thread coupling and
coupling involving a filler, such as a grout or an epoxy. The
splice may include a central tapered-thread central sleeve or
coupler, and a pair of collars that are screwed onto
externally-threaded ends of the central sleeve. The central sleeve
has a channel therethrough with tapered internal threads at both
ends, and a center internal relief. The internal relief is an
increased radius center portion that ensures full thread contact
between the tapered internal threads and external threaded sections
of the rebar ends. The sleeve has externally-threaded ends that are
engaged by internally-threaded ends of a pair of collars. Distal to
their internally-threaded ends, the collars have
filler-material-receiving channels. The channels include plural
sloped surfaces for aiding in securing filler material between the
collars and the rebar ends. The sloped surfaces also transfer some
of the load from the rebar ends to the collars, thus reducing the
amount of load on the tapered coupling between the bar ends and the
central sleeve. The filler material may be an epoxy or grout, or
may alternatively be another suitable material, such as a reactive
metal-producing material.
[0023] FIGS. 1-4 show a reinforcing bar splice or coupling 10
joining together a pair of reinforcing bar ends 12 and 14. The
splice 10 includes a central sleeve 16, and a pair of collars 18
and 20 that are physically coupled to ends of the central sleeve
16. In short, the reinforcing bar ends 12 and 14 are coupled to the
sleeve 16 by an engagement of tapered threads, and are coupled to
the collars 18 and 20 by a suitable filler material, such as epoxy
or grout.
[0024] The sleeve 16 includes a central through-hole 24. The ends
26 and 28 of the sleeve 16 are internally threaded along the hole
24 at tapered thread portions 30 and 31 of the hole 24, with
respective tapered threads 32 and 34. The tapered threads 32 and 34
are configured to engage corresponding externally-threaded tapered
portions 36 and 38 of the rebar ends 12 and 14. The rebar ends 12
and 14 are coupled to the central sleeve 16 by rotating the ends 12
and 14, and/or the sleeve 16, to threadedly engage the rebar end
threaded portions 36 and 38 with the tapered threads 32 and 34 of
the sleeve. In this manner the sleeve 16 becomes a tensile and
compressive extension of the reinforcing bar ends 12 and 14.
Further details regarding threaded rebar coupling may be found in
U.S. Pat. No. 5,366,672, the description and drawings of which are
herein incorporated by reference.
[0025] The sleeve 16 has a center internal relief 40 in a center
portion of the hole 24. The internal relief 40 is an increased
radius center portion that ensures full thread contact between the
tapered internal threads 32 and 34 and the external threaded
sections or portions 36 and 38 of the rebar ends 12 and 14. The
internal relief 40 ensures that the rebar ends 12 and 14 can be
inserted in the sleeve through-hole 24 past the last engaged thread
of the internally-threaded portions 32 and 34. The internal relief
40 also relieves thread stress concentrations, and thus may help
eliminate or retard fatigue crack initiation.
[0026] The sleeve 16 has external threads 42 and 44 at the sleeve
ends 26 and 28. The external threads 42 and 44 engage respective
first (proximal) ends 48 and 50 of the collars 18 and 20. The
collar first ends 48 and 50 have internal threads 52 and 54
configured to engage the sleeve external threads 42 and 44, to
couple the collars 18 and 20 to the sleeve ends 26 and 28. The
collars 18 and 20 are coupled to the sleeve ends 26 and 28 by
suitable aligning and rotating the collars 18 and 20 and/or the
sleeve 16 to threadedly engage them.
[0027] The collars 18 and 20 have respective through-holes 52 and
54 for allowing the rebar ends 12 and 14 to pass therethrough for
threaded coupling to the central sleeve 16. As described in the
previous paragraph, at the first collar ends 48 and 50 the
through-holes 52 and 54 are internally threaded to engage the
sleeve ends 26 and 28. At second (distal) collar ends 58 and 60 the
through-holes 52 and 54 have respective filler-material-receiving
channels 62 and 64. The channels 62 and 64 have a diameter that is
greater than that of the rebar ends 12 and 14. The diameter of the
channels 62 and 64 is also greater than a maximum diameter of the
sleeve through-hole 24 at the internal threads 32 and 34 (at the
mouths of the through-hole 24). The channels 62 and 64 are sized to
allow entry of filler material 66 after the rebar ends 12 and 14
have been inserted through the collars 18 and 20, and threadedly
engaged with the central sleeve 16. Thus spaces 68 and 70 within
the collars 18 and 20, around the rebar ends 12 and 14, may be
filled with the filler material 66, to aid in securing the rebar
ends 12 and 14.
[0028] The channels 62 and 64 each include plural sloped surfaces
for aiding in securing filler material between the collars and the
rebar ends. In the illustrated embodiment each of the channels 62
and 64 has four sloped surfaces, although it will be appreciated
that a greater or lesser number of sloped surfaces may be employed.
The channel 62 has sloped surfaces 71, 72, 73, and 74, and the
channel 64 has sloped surfaces 75, 76, 77, and 78. The sloped
surfaces 71-78 are angled so that they are directed radially
inward, such that they are closer to the rebar ends 12 and 14 where
they are closer to the distal collar ends 58 and 60, away from the
sleeve 16. The sloped surfaces 71-78 transfer some of the load from
the rebar ends 12 and 14 to the collars 18 and 20, thus reducing
the amount of load on the tapered thread coupling between the bar
ends 12 and 14, and the central sleeve 16. Because of the sloped
surfaces 71-78, tensile stresses on the rebar ends 12 and 14, are
in part converted into compression stresses in the filler material
66. These compression stresses in the filler material 66 are
converted, via the sloped surfaces 71-78, into hoop stresses in the
collars 18 and 20. Since filler materials such as grout or epoxy
are stronger in compression than in tension, it will be appreciated
that it is advantageous to transform tension stresses in the rebar
end 12 and 14, into compression stresses in the filler material 66.
Further, the collars 18 and 20, being made of metal, resist hoop
stresses very well, and therefore it is advantageous to dissipate
compression stresses in the filler material 66 as hoop stresses in
the collars 18 and 20.
[0029] The sleeve 16 and the collars 18 and 20 may be made of a
suitable material, such as steel. The filler material for the
collars 18 and 20 may be an epoxy or grout, or may alternatively be
another suitable material, such as a reactive metal-producing
material, such as used in ERICO systems sold under the trademark
CADWELD.RTM..
[0030] In assembly, the collars 18 and 20 are first threadedly
engaged on the external threads 42 and 44 of the sleeve ends 26 and
28. Then the rebar ends 12 and 14 are threadedly engaged with the
internal tapered threads 32 and 34. (The two proceeding steps may
be reversed in order, if desired.) Finally the spaces 68 and 70 are
filled with the filler material 66. A grout or epoxy filler
material is allowed to cure, to complete the splice 10.
[0031] The splice 10 advantageously disperses or spreads stress out
over a larger area of the rebar ends 12 and 14. Since some of the
stress on the rebar ends 12 and 14 is transferred to the collars 18
and 20, rather than the central sleeve 16, the splice 10 is better
able to withstand stress, and may have better fatigue
performance.
[0032] The splice 10 has better performance than conventional
tapered thread splices with regard to two fatigue failure modes.
One mode where conventional tapered thread splices fail is due to
failure of the rebar at the middle of the tapered thread sleeve.
The presence of the internal relief 40 at the middle of the sleeve
16 helps prevent this type of failure.
[0033] Another type of failure in conventional tapered thread
splices is failure of the rebar at the mouth of the tapered thread
sleeve, where the rebar ends exit the sleeve. The presence of the
filler material 66 at this location in the splice 10 helps reduce
stresses, aiding in avoiding this sort of failure as well.
[0034] It will be appreciated that the splice 10 shown in the
figures and described above is but one embodiment of the invention.
Many variations are possible, including different ways of
physically coupling a sleeve and collars, and different ways of
configuring the sleeve and/or the collars. Some of the features
described herein may be omitted, if desired, or may be combined
with other features.
[0035] Although the invention has been shown and described with
respect to a certain preferred embodiment or embodiments, it is
obvious that equivalent alterations and modifications will occur to
others skilled in the art upon the reading and understanding of
this specification and the annexed drawings. In particular regard
to the various functions performed by the above described elements
(components, assemblies, devices, compositions, etc.), the terms
(including a reference to a "means") used to describe such elements
are intended to correspond, unless otherwise indicated, to any
element which performs the specified function of the described
element (i.e., that is functionally equivalent), even though not
structurally equivalent to the disclosed structure which performs
the function in the herein illustrated exemplary embodiment or
embodiments of the invention. In addition, while a particular
feature of the invention may have been described above with respect
to only one or more of several illustrated embodiments, such
feature may be combined with one or more other features of the
other embodiments, as may be desired and advantageous for any given
or particular application.
* * * * *