U.S. patent application number 14/742642 was filed with the patent office on 2015-10-08 for carpet seaming iron.
The applicant listed for this patent is Crain Cutter Company, Inc.. Invention is credited to Gregory Joseph Chambers, Lance Darrell Crain, Tan Dinh Nguyen.
Application Number | 20150282656 14/742642 |
Document ID | / |
Family ID | 48653519 |
Filed Date | 2015-10-08 |
United States Patent
Application |
20150282656 |
Kind Code |
A1 |
Crain; Lance Darrell ; et
al. |
October 8, 2015 |
CARPET SEAMING IRON
Abstract
A carpet seaming iron includes a base assembly and a top cover,
within which the heating and control components are located. A
bimetal thermostat, an over-temperature cutoff, and/or a thermistor
and thermistor cover are secured between the base assembly and top
cover by an elevated surface of the base assembly. The base
assembly may include a base having an outer groove such that the
top cover that fits over the base and in the outer groove of the
base. To keep the cord away from a user during operation, the
handle of the carpet seaming iron may also be attached to the cord
by a rotatable cord guard holder that extends the cord away from
the handle and a semi-rigid cord guard that reduces bending of the
cord.
Inventors: |
Crain; Lance Darrell;
(Pleasanton, CA) ; Chambers; Gregory Joseph;
(Morgan Hill, CA) ; Nguyen; Tan Dinh; (Milpitas,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Crain Cutter Company, Inc. |
Milpitas |
CA |
US |
|
|
Family ID: |
48653519 |
Appl. No.: |
14/742642 |
Filed: |
June 17, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13335873 |
Dec 22, 2011 |
9085848 |
|
|
14742642 |
|
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|
|
Current U.S.
Class: |
219/251 |
Current CPC
Class: |
B29C 66/43 20130101;
A47G 27/0443 20130101; B29C 66/91211 20130101; B29C 66/91421
20130101; B29C 66/91431 20130101; D06F 75/08 20130101; B29C 66/8612
20130101; B29C 65/30 20130101; D06F 75/26 20130101; B29C 66/87441
20130101; B29C 66/1142 20130101; D06F 75/28 20130101; B29C 66/836
20130101; B29C 66/91213 20130101; B29C 65/18 20130101; B29C 65/5042
20130101; B29C 65/4815 20130101; B29C 66/91231 20130101 |
International
Class: |
A47G 27/04 20060101
A47G027/04; B29C 65/30 20060101 B29C065/30; B29C 65/00 20060101
B29C065/00; B29C 65/18 20060101 B29C065/18 |
Claims
1. A carpet seaming iron comprising: a bimetal thermostat; a base
assembly having a surface on which the bimetal thermostat is
positioned; and a bimetal thermostat top cover coupled to the base
assembly, the bimetal thermostat top cover securing the bimetal
thermostat to the base assembly.
2. The carpet seaming iron of claim 1, wherein the surface of the
base assembly on which the bimetal thermostat is positioned
includes a post that extends from a base of the base assembly and
fits through a hole of the bimetal thermostat.
3. The carpet seaming iron of claim 1, wherein the bimetal
thermostat top cover is coupled to the base assembly by one or more
fasteners.
4. The carpet seaming iron of claim 1, wherein the bimetal
thermostat top cover is coupled to the base assembly at one or more
locations of the base assembly that are thicker than the surface on
which the bimetal thermostat is positioned.
5. The carpet seaming iron of claim 1, wherein the bimetal
thermostat top cover secures the bimetal thermostat to the base
assembly at a first base assembly surface upon which the bimetal
thermostat is positioned, and the bimetal thermostat top cover is
secured to the base assembly at a second base assembly surface, the
bimetal thermostat being secured by applying a force to the bimetal
thermostat top cover towards the base assembly, and the bimetal
thermostat top cover transferring at least a portion of the force
to the bimetal thermostat.
6. The carpet seaming iron of claim 1, further comprising: an
over-temperature cutoff and a top cover, wherein the
over-temperature cutoff is mounted between the base assembly and
the top cover, and the over-temperature cutoff is secured by the
base assembly by the top cover contacting the over temperature
cutoff.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 13/335,873, filed Dec. 22, 2011, which is incorporated by
reference in its entirety.
BACKGROUND
[0002] This invention relates generally to flooring tools, and in
particular to carpet seaming irons.
[0003] A carpet seaming iron is a tool commonly used in the
installation of carpet in residential settings. The carpet is
delivered to the home as a roll good of fixed width. A carpet
installer cuts lengths of the carpet off the roll and fits them to
the various rooms. As the carpet off the roll is often not as wide
as the width of some rooms, seams between two pieces are often
necessary. An electric carpet seaming iron is used in conjunction
with carpet seaming tape to create such seams. The carpet seaming
tape is placed beneath two pieces of carpet to be seamed and
centered beneath the seam area. The carpet seaming iron is placed
on the tape to melt the thermoplastic adhesive on the face of the
carpet seaming tape. Once the thermoplastic adhesive is melted, the
iron is moved forward, and the carpet backing is pressed into the
molten area of thermoplastic adhesive behind the iron. Once the
thermoplastic adhesive cools, the tape forms a permanent patch on
the carpet's backing that effectively joins together the adjacent
pieces of carpet.
[0004] In the design of a carpet seaming iron, for ease of use, it
is preferred that the iron's base containing the heating element
and temperature controls have as thin a profile as possible. As the
iron is moved between the carpet edges in the area to be seamed, a
shorter overall thickness (or height) of base creates less
disturbance of the carpet that is being seamed. Furthermore, it is
preferred to form ribbed surfaces called "grooves" in the base of a
carpet seaming iron. These function to form the thermoplastic
adhesive of the carpet seam tape into beads just prior to being
pressed into the carpet backing These beads are thought to improve
the penetration of the thermoplastic adhesive as it is pressed into
the rough, porous carpet backing This works to improve the strength
of the seam. In addition to grooves, some of the carpet seaming
irons disclosed in the above references include even deeper "center
channels" in the base which form the adhesive into a heavier bead
at the center of the seam where the two carpet edges are joined.
The heavy center bead can function either to strengthen the seam
along its centerline, or else can "butter" the edges of the carpet
being seamed to seal the edges and prevent their unraveling.
[0005] These grooves and/or center channels create a problem in the
manufacturing of carpet seam irons in that, within the valley area
of these grooves or channels, there results an unusually thin
cross-section in the base. The thin cross-sections present a
problem in that it is desirable to mount certain
temperature-sensing components of the carpet seaming iron directly
to the base. Such components might include a bimetal thermostat,
thermistor (in the case of electronic control), or over-temperature
cutout. A prior art bimetal thermostat 10 including a typical
fastener 11 used to fasten it to an iron base through a hole 12 is
shown in FIG. 1. A prior art over-temperature cutoff 30 including
two screws 31 used to fasten it to an iron base through holes 32 is
shown in FIG. 2. Existing carpet seaming irons have used holes
through the iron's base to mount bimetal thermostats and
over-temperature cutoffs to the base, and other carpet seaming
irons have mounted a thermistor to the iron base using a bracket
with a screw and tapped hole.
[0006] But the use of conventional threaded fasteners and tapped
holes to fasten components to the base of a carpet seaming iron can
present problems. In the valley areas of grooves and channels,
there is often insufficient material thickness remaining to form
the necessary threads. The difficulty of tapping in such areas can
result in unreliable production, a high scrap rate, and an
unacceptably high number of field failures. What is needed is an
improved means of fastening the necessary components to the base of
the iron.
[0007] In addition, most prior art carpet seaming irons include a
heat shield mounted within the assembly so that it is suspended
above the base. This creates a gap between the heat shield and the
base. This gap functions to reduce heat transfer between the heat
shield and the base. It is preferred that the heat shield remain
relatively cool (in comparison with the heating element) to protect
the carpet as it passes over the heat shield. However, in order to
further reduce heat transfer between the iron base and the heat
shield, some irons include a gasket between the base and the heat
shield. In irons including such a gasket, the gasket is normally
placed on top of the iron's base. When the heat shield is fastened
onto the iron, it then functions to hold the gasket down on the
base.
[0008] However, providing a suitable gasket for the carpet seaming
iron can be problematic because few available materials are
certified to withstand the heat in this area of the carpet seaming
iron (estimated up to 450 degrees). One common material is a high
temperature silicone rubber, but such materials are soft, porous,
and easily sliced apart when contacted by rough or sharp items such
as knives that are commonly found in a tool box. What is needed is
an improved means of forming a seal between the base of the iron
and the heat shield.
[0009] Another unusual problem in the design of a carpet seaming
iron is providing a convenient means of tending the power cord.
Unlike clothes irons, in the use of a carpet seam iron, the user's
focus is normally at the back of the device. This is the area where
the carpet seam is put together and pressed into the molten
thermoplastic adhesive. However, in the most popular carpet seam
iron designs, the power cord comes out at the back of the handle
and tends to get right in the way of the user's work. Hence, cord
tenders have become a standard feature formed integrally as part of
the handle of a carpet seaming iron specifically for the purpose of
keeping the cord out of the user's way.
[0010] The most common type of prior art cord tender has a left
indent, a center indent, and a right indent. A power cord can be
positioned within either of the left indent or the right indent to
position the cord to the right of the left, thus keeping it out of
the working area at the back of the iron. The center indent is most
often used to save space when the iron is put away and not in
use.
[0011] Problems exist with this type of cord tender. First, the
power cord must come with a strain relief over the cord jacket at
the exit point from the handle. This strain relief must be flexible
enough to permit positioning of the cord within the indents.
However, it must also provide enough resistance to cord bending so
that the cord is not easily bent into a tight radius that can
damage the inner conductors.
[0012] The strain relief commonly disclosed in prior art carpet
seaming irons is a "pigtail type" strain relief manufactured from
steel wire and similar in appearance to a coil spring. Such
pigtail-type strain reliefs terminate in a flared end to ensure a
gradual bend radius at the exit of the strain relief when the cord
is pulled or bent.
[0013] Problems also exist with the prior art cord tender when used
in conjunction with a pigtail-type strain relief. Because the power
cord and strain relief must be somewhat flexible, the power cord,
even when positioned within an indent of the prior art cord tender,
tends to droop under its own weight. Furthermore, as the iron is
moved, the cord is pulled in the opposite direction due to being
connected at the electrical receptacle at the wall. For these
reasons, the cord can tend to move again towards the back of the
iron, and into the way of the user's work.
[0014] To solve this problem, other prior art irons have used a
"strain relief bracket," which can support and extend the power
cord further away from the iron handle to the left or right. One
example works with a prior art cord tender and pigtail-type
strain-relief. It consists of a tubular section with a jaw on one
end and a distal end forming the exit location for the cord. The
tubular section may have a longitudinal slot allowing it to fit
over the body of the pigtail strain relief. Thus, to affix the
bracket over the pigtail strain relief, the user slightly tugs on
the flared end of the pigtail-type strain relief to lengthen it,
and then fits the tubular section over the strain relief. When the
flared end is released, the spring retracts against distal end of
the device, holding it in position. The opposite jaw end of the
device is designed to be positioned within the cord tender and hook
itself within the valley formed by the left and right indents.
[0015] The strain relief bracket can be made from any semi-rigid
material such as plastic, wood, or metal, and it may be formed as a
single piece by molding. The device may not have the longitudinal
slot, and is therefore meant to be permanently mounted to the
assembly of the cord and strain relief, or the bracket may be
mounted to the end of the iron handle using a ball joint and socket
arrangement with the socket provided on the end of the handle and a
ball joint extending from the end of the spacer arm. The spacer arm
may be a top portion of a jaw area where strain relief bracket is
hooked onto the cord tender portion of the iron handle. Relative to
the handle, the spacer arm is a proximate end of the device. Such a
bracket would conceivably be made from the same "semi-rigid"
plastic, wood, or metal material.
[0016] One prior art iron uses a strain relief having a ball-shaped
end that is formed through the joining of two end components. Both
components may be made from a semi-rigid material, but on the "ball
end" of the strain relief the iron also includes a round flanged
shape. The two halves of the handle, when fastened together,
internally form a pair of walls that retain this flange, while also
permitting it to rotate. The iron thus includes a semi-rigid strain
relief with an elongate tubular section that can rotate within its
confines in the first handle half and second handle half. This
achieves the object of extending the cord a distance away from the
working area at the back of the iron.
[0017] But the strain relief bracket of this design has a problem
in that the semi-rigid construction that provides the benefit of
extending the cord also tends to defeat the function of the
underlying strain relief. As the cord exits at a distal end 34, it
is subject to the same stresses and wear that the underlying strain
relief is supposed to reduce. Without a suitably flexible strain
relief in such an area, the cord is likely to make a sharp bend
whenever it is tugged off its axis, which can cause cord conductor
damage. Because the strain relief of other devices are made from
the same semi-rigid materials, they can have the same problems at
the cord exit. Even if the designs include cutouts in the tubular
extension area of their strain relief to make it more flexible,
these cutouts are not as effective as they might be due to the use
of semi-rigid material. Moreover, the semi-rigid material is
brittle, causing the cutouts to crack over time and fail. Once the
strain relief cracks, sharp bends of the cord become likely at the
failure point.
[0018] Therefore, a strain relief is needed at the cord exit from
any semi-rigid or rigid device component, such as a handle. The
strain relief is preferably both flexible enough to form the cord
into a gradual bend as it is tugged, while at the same time being
resilient enough to prevent the cord from forming sharp bends. What
is needed is an improved cord tender assembly for a carpet seaming
iron that both tends the cord to the left or the right away from
the working area at the back of the iron, while also providing
effective strain relief in the attached power cord.
SUMMARY
[0019] In one embodiment, a carpet seaming iron comprises a bimetal
thermostat, a base assembly having an elevated surface for securing
the bimetal thermostat laterally with respect to a plane of the
base assembly, and a top cover coupled to the base assembly, the
top cover securing the bimetal thermostat to the base assembly.
Similarly, an over-temperature cutoff may be mounted between the
base assembly and the top cover. In another embodiment, the carpet
seaming iron includes a thermistor and a thermistor cover
configured to fit over the thermistor, rather than the bimetal
thermostat, and the thermistor and thermistor cover are secured
between the base assembly and top cover. In this way embodiments of
the carpet seaming iron fasten the necessary components to the base
of the iron, such as a bimetal thermostat, an over-temperature
cutoff, and/or a thermistor, without requiring a hole and fastener
through the base of the iron.
[0020] In another embodiment, a carpet seaming iron comprises a
base having an outer groove, a top cover that fits over the base
with at least a portion of the top cover in the outer groove of the
base, and a heating element thermally coupled to the base and one
or more components for controlling the heating element disposed
between the base and the top cover within the outer groove.
Embodiments of the carpet seaming iron thus form a seal between the
base of the iron and the heat shield, protecting the components of
the iron, without requiring a gasket or equivalent structure
therebetween.
[0021] In another embodiment, a carpet seaming iron comprises a
base assembly having a heating element, the base assembly
configured for operation of the carpet seaming iron in a first
axis, a handle assembly attached to the base heating assembly, and
a cord electrically coupled to the heating element of the base
assembly through the handle assembly. To keep the cord away from a
user during operation, the iron further comprises a rotatable cord
guard holder comprising a rigid swivel member that is rotatably
coupled to the handle about the first axis, the rotatable cord
guard holder extending the cord in a direction at an angle to the
first axis, along with a semi-rigid cord guard coupled to the cord
where the cord extends from the rotatable cord guard holder, the
cord guard reducing bending of the cord where the cord guard is
coupled to the cord. Embodiments of the carpet seaming iron thus
provide a cord tender assembly that both tends the cord to the left
or the right away from the working area at the back of the iron,
while also providing effective strain relief in the attached power
cord.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 illustrates an example prior art bimetal
thermostat.
[0023] FIG. 2 illustrates an example prior art over-temperature
cutoff.
[0024] FIG. 3 is an exploded assembly view of a lower portion of a
carpet seaming iron having a bimetal thermostat and
over-temperature cutoff fastening system, in accordance with an
embodiment of the invention.
[0025] FIG. 4 is a perspective view of the lower portion of a
carpet seaming iron of FIG. 3, assembled, in accordance with an
embodiment of the invention.
[0026] FIG. 5 is an exploded assembly view of a handle assembly of
a carpet seaming iron with a cord guard assembly, in accordance
with an embodiment of the invention.
[0027] FIG. 6 is a perspective view of the carpet seaming iron with
the handle assembly and cord guard assembly of FIG. 5, assembled,
in accordance with an embodiment of the invention
[0028] FIG. 7 illustrates an element cover of a carpet seaming
iron, in accordance with an embodiment of the invention.
[0029] FIG. 8 is an exploded assembly view of a lower portion of a
carpet seaming iron having a thermistor fastening system, in
accordance with an embodiment of the invention
[0030] FIG. 9 is a perspective view of the thermistor cover of FIG.
8, in accordance with an embodiment of the invention.
[0031] The figures depict various embodiments of the present
invention for purposes of illustration only. One skilled in the art
will readily recognize from the following discussion that
alternative embodiments of the structures and methods illustrated
herein may be employed without departing from the principles of the
invention described herein.
DETAILED DESCRIPTION
[0032] To provide an improved means of fastening a bimetal
thermostat or over-temperature cutoff to the base of the iron,
posts may be formed in a top surface of the base where such
components are preferred to be positioned, as shown in FIG. 3. Base
1000 includes a surface 1003 at a first elevation of a recess that
provides clearance for installing these components. Base 1000
includes a post 1005 to for mounting bimetal thermostat 1025. Base
1000 includes another pair of posts 1010 for mounting an
over-temperature cutoff 1080. Base 1000 includes an "S-shaped"
groove (not shown) for inserting heating element 1015.
[0033] A bimetal thermostat 1025 typically is constructed with a
through hole 1026. In prior art irons, a fastener is passed through
hole 1026 to fasten it to the base. In one embodiment of the
invention, bimetal thermostat 1025 is placed on a surface 1008 with
a post 1005 inserted into hole 1026, instead of a fastener. Surface
1008 is slightly elevated from bottommost surface 1003 to provide
operating clearance for a lower arm (best seen as lower arm 13 of
bimetal thermostat 10 in FIG. 1) of the bimetal thermostat 1025.
Post 1005 is a first hold point to fix the position of bimetal
thermostat 1025 at its back end 1027. Next element cover 1030
covering heating element 1015 is fastened to base 1000 by means of
five screws 1032 passing through five holes 1034 and fastening into
five tapped holes 1007 of base 1000. Five holes 1007 are drilled
and tapped into a surface 1009 corresponding to a second, higher
elevation on base 1000. The thicker cross-section of this area is
more than sufficient for the formation of the necessary threads. By
contrast, the cross section of the base at surface 1003 or surface
1008, corresponding to typical locations for the tapped hole for a
screw holding the bimetal thermostat (or thermistor bracket) of
prior art irons is comparatively thin and insufficient for the
formation of the necessary threads.
[0034] After the fastening of top cover 1030 to base 1000, a
bracket 1040 is placed on a top surface 1028 of bimetal thermostat
1025. Bracket 1040 is then fastened to top cover 1030 by two screws
1042 passing first through two holes 1044 in bracket 1040 and then
passing through two holes 1036 of top cover 1030. Two screws 1042
are then fastened into two tapped holes 1006 of base 1000. The two
tapped holes 1006 are also formed into surface 1009 at the second,
higher elevation on base 1000 that is suitable for forming
threads.
[0035] Bracket 1040 once tightened down in this manner bears upon
top surface 1028 of bimetal thermostat 1025, holding it down as a
second hold point. The pressure created by bracket 1040 on a top
surface 1028 of bimetal thermostat 1025 is made possible by the
controlled height of surfaces 1037 in relation to top surface 1028
of bimetal thermostat 1025. When bracket 1040 is initially placed
on a top surface 1028 of bimetal thermostat 1025, there is a small
amount of clearance between its bottom surfaces 1045 and surfaces
1037 of element cover 1030. Thus, when bracket 1040 is tightened
down with screws 1042, a tension is created effectively strapping
bimetal thermostat 1025 down.
[0036] Next in the assembly top cover 1050 is placed on element
cover 1030 such that three element cover posts 1038 extend through
three holes 1052 of top cover 1050. Top cover 1050 additionally has
a precision thermostat hole 1054 which closely fits a collar 1029
of bimetal thermostat 1025, forming a third hold point. Bimetal
thermostat 1025 is thus prevented from pivoting to the left or
right by the precision fit of bimetal thermostat collar 1029 being
surrounded by thermostat hole 1054 of top cover 1050.
[0037] As shown in FIG. 3, next an insulator pad 1060 is affixed to
a top surface of top cover 1050. Afterwards, a heat shield 1070 is
placed over the three element cover posts 1038. Heat shield 1070 is
fastened to element cover 1030 by three screws 1071 being fastened
into three tapped holes 1039 of element cover 1030. This in turn
fastens top cover 1050 down on element cover 1030
[0038] An improved means to fasten an over-temperature cutoff is
also shown in FIG. 3. In prior art irons, as shown in FIG. 2,
fasteners such as fasteners 31 were used to fasten an
over-temperature cutoff 30 by passing them through holes 32 and
fastening them in tapped holes in the base. In one embodiment of
the invention, as shown in FIG. 3, a pair of posts along with a tab
formed in the top cover are used to position and hold down an
over-temperature cutoff. Over-temperature cutoff 1080 includes two
holes 1082 and a flat 1083 in its top surface. Over-temperature
cutoff 1080 is mounted on base 1000 with two posts 1010 of base
1000 extending through two holes 1082 of over temperature cutoff
1080. The two posts 1010 form two hold points for over-temperature
cutoff 1080, preventing it from turning in any direction.
[0039] Furthermore, when top cover 1050 is placed on element cover
1030 with three posts 1038 extending through three holes 1052, a
tab 1055 of top cover 1050 contacts flat 1083 in the top surface of
over-temperature cutoff 1080. Top cover 1050 is then fastened down
with heat shield 1070 by three screws 1071 fastening into three
tapped holes 1039 of element cover 1030. After top cover 1050 is
fastened, tab 1055 of top cover 1050 generates sufficient pressure
on flat 1083 of over-temperature cutoff 1080 to securely hold it
down. Thus tab 1055 forms a third hold point for over-temperature
cutoff 1080.
[0040] FIG. 4 shows a perspective view of the assembly up to the
point where top cover 1050 has been placed on top of element cover
1030. This view shows the close fit of thermostat hole 1054 of top
cover 1050 with collar 1029 of bimetal thermostat 1025. This close
fit prevents bimetal thermostat 1025 from moving to the left or to
the right. This view also shows tab 1055 contacting a flat 1083 in
the top surface of over-temperature cutoff 1080. Tab 1055 holds
over-temperature cutoff 1080 down onto the interior surface of base
1000 where it is positioned (as by posts 1010 in FIG. 3).
[0041] The improved means of fastening components such as a
thermostat or over-temperature cutoff to the base of carpet seaming
iron (such as shown in FIG. 3) can be used to improve most all
prior art irons. Benefits might include reduced scrap and less
field failures resulting from no longer needing to tap a hole in a
thin cross-section of the base.
[0042] To provide an improved means of forming a seal in the gap
area between the base of the iron and the heat shield, FIG. 3 shows
that base 1000 includes an element cover groove 1001. Element cover
1030 has an element cover rib 1031 forming a close fit with element
cover groove 1001 of base 1000. As better shown in FIG. 7, a view
of element cover 1030 turned upside-down, element cover rib 1031
forms a raised edge surface around the perimeter of element cover
1030. As shown in FIG. 3, element cover rib 1031 seats within
element cover groove 1001 of base 1000. When element cover 1030 is
tightened down with pressure from all the fasteners shown
(including five top cover fasteners 1032, two bracket fasteners
1042, and three heat shield fasteners 1071), element cover rib 1031
forms an effective seal with element cover groove 1001 of base
1000. Thus, a seal is created which is located in the gap between
heat shield 1070 and base 1000 which does not require the gasket of
prior art irons as previously discussed. Because this iron does not
require such a gasket, the area above the element cover 1030 can be
open for improved airflow. This helps reduce heat transfer between
base 1000 and heat shield 1070, protecting the carpet from
damage.
[0043] To provide an improved cord tender for a carpet seaming
iron, an improved rotatable cord guard assembly 2070 is shown in
FIG. 5. As viewed from the back of the iron, a left handle half
2010 and a right handle half 2030 are being assembled onto heat
shield 2000. Prior to fastening these handle halves, rotatable cord
guard assembly 2070 is sub-assembled. Rotatable cord guard assembly
2070 includes cord guard 2075 (referred to a "strain-relief" by
consumers but as a cord guard in industry). Cord guard 2075 is
positioned near an end portion of an elongate power cord 2082.
Rotatable cord guard assembly 2070 includes a left cord guard
holder 2080 and a right cord guard holder 2090.
[0044] Internally, left cord guard holder 2080 and right cord guard
holder 2090 have certain symmetrical features, such that when
fastened together, they form two pairs of holding surfaces on cord
guard 2075 and one pair of holding surfaces on cord jacket surface
2071 of power cord 2082. A first pair of inside edges 2081, 2091
bear on a flanged surface 2076 of cord guard 2075. Secondly, a
square shape 2083 on left cord guard holder 2080 and a round shape
2093 of right cord guard holder 2090 insert within a "half-round"
groove 2079 formed in cord guard 2075. The square shape 2083 bears
against a flat (not shown) on "half-round" groove 2079. Cord guard
2075 is thus keyed internally within left cord holder 2080 and
right cord holder 2090 to prevent it from rotating. Lastly, a pair
of ribs 2085, 2095 grip cord jacket 2071. These features of left
cord guard holder 2080 and a right cord guard holder 2090 once
fastened together as by two screws 2099 securely grip cord guard
2075 and power cord 2082, preventing it from pulling out of the
assembly.
[0045] Once left cord guard holder 2080 and right cord guard holder
2090 are fastened together, they form cylindrical-shaped forward
flange 2087 and a rearward flange 2088. Forward flange 2087 fits in
a forward hole 2015 formed by rounds 2011 and 2031 (of left handle
half 2010 and a right handle half 2030 respectively). The small
diameter area of forward flange 2087 rotatably fits within forward
hole 2015, while the larger diameter rim fits behind forward hole
2015 and is held in place against the inner wall behind rounds 2011
and 2031. Similarly, rearward flange 2088 fits in a rearward hole
2017 formed by two rounds 2012 and 2032. The small diameter area of
rearward flange 2088 rotatably fits within rearward hole 2017,
while the larger diameter rim fits behind reward hole 2017 against
the inner wall formed by rounds 2012 and 2032.
[0046] FIG. 6 shows the fully-assembled improved carpet seaming
iron 7000 including a rotatable cord guard assembly 7020. As shown,
axis X defines a first axis of operation of the carpet seaming iron
7000. Cord guard holder 7090 extends cord 7095 at an angle to axis
X. Rotatable cord guard assembly 7020 will rotate approximately 180
degrees along arc A on the axis of forward flange 7015 and rearward
flange 7017. Because rotatable cord guard assembly 7020 can tend
the cord to the left or the right such that is out of the user's
way, it performs the function of prior art cord tenders without the
drawbacks. The power cord 7095 will be extended a distance B to the
left or right from the centerline of carpet seaming iron 7000.
While flexible cord guard 7075 is flexible, it is still resilient
enough to extend power cord 7095 by distance B it extends from cord
guard holder 7090.
[0047] Furthermore, rotatable cord guard assembly 7020 is rotatably
connected to handle assembly 7011 at two holes 7076, 7077 which
form two points of rotation. This increases the strength of handle
assembly 7011 and rotatable cord guard assembly 7020 to resist
strong pulls on power cord 7095, possible leveraging of cord guard
7075, or unforeseeable impact forces.
[0048] Furthermore, rotatable cord guard assembly 7020 is comprised
of multiple components that can be manufactured from different
materials that are suitable for their respective functions. Cord
guard holder 7090 (formed similarly to the embodiment of FIG. 5 by
a left cord guard holder 2080 and a right cord guard holder 2090)
could be molded from a rigid and hard material such as fiberglass
reinforced nylon plastic. Such a material is suitable for holding
flexible cord guard 7075 from pulling out, as well as for repeated
rotation wear within two holes 7076, 7077. Flexible cord guard 7075
itself can be flexible and can be formed from a comparatively soft
material, such as thermoplastic rubber.
[0049] The use of a flexible cord guard 7075, in one embodiment,
ensures that a gradual bend will naturally form in the power cord
7095 whenever it is tugged off its axis. By contrast, with the
semi-rigid strain relief of previous devices, the cord may form a
sharp bend past the cord exit point and thus more likely to cause
cord failure.
[0050] FIG. 8 shows an alternative embodiment showing several
elements in common with those of the thermostat and
over-temperature cutoff fastening system of FIG. 3. However, in the
embodiment of FIG. 8 they are assembled in a slightly different
manner to fasten a thermistor-type temperature-sensing device to
the iron base. A thermistor may be used when an electronic control
circuit is employed for iron temperature control.
[0051] A thermistor 16030 is placed at surface 16020 of base 16010.
Base 16010 is similar to base 1000 (FIG. 3). A thermistor holder
16040 having a bottom surface 16045 conforming to the profile of
thermistor 16030 is placed on top of thermistor 16030. As more
clearly shown in FIG. 9, thermistor cover 16040 has a bottom
surface 16045 including a groove 16041 for holding thermistor 16030
(FIG. 8). Thermistor cover 16040 additionally includes a blind hole
16042 which accepts post 16013 of base 16010 (FIG. 8), and a boss
16043 which enters slot 16012 (of base 16010, FIG. 8). Thus, blind
hole 16042 of thermistor cover 16040 accepts post 16013 of base
16010 (FIG. 8) as a first hold point. Boss 16043 enters slot 16012
(of base 16010, FIG. 8) as a second hold point to prevent
thermistor cover 16040 from rotating. As shown in FIG. 8,
thermistor cover 16040 additionally has a boss 16047 on a top
surface 16049.
[0052] Element cover 16130 covering element 16011 is next fastened
to base 16010 as by five screws 16135 passing through five holes
16137 and fastening into five tapped holes 16015 of base 16010.
Element cover 16130 is similar to element cover 1030 (FIG. 3). Next
a bracket 16140 is placed on top of thermistor cover 16040 with a
boss 16047 extending through center hole 16146 of bracket 16140.
Center hole 16146 cooperates with boss 16047 of thermistor cover
16040 as a third hold point to prevent thermistor cover 16040 from
rotating. Bracket 16140 is similar to bracket 1040 (FIG. 3) except
for that it is turned upside down. Bracket 16140 is fastened down
by two screws 16142 passing first through bracket holes 16144. Two
screws 16142 then pass through two holes 16136 in element cover
16130 and fasten into two tapped holes 16017 of base 16010.
[0053] Bracket 16140 once tightened down in this manner bears upon
top surface 16049 of thermistor cover 16040, holding it down as a
fourth hold point. A slight amount of pressure created by bracket
16140 on a top surface 16049 of thermistor cover 16040 is made
possible by a controlled height of surfaces 16139 in relation to a
top surface 16049 of thermistor cover 16040. When bracket 16140 is
placed on a top surface 16049 of thermistor cover 16040, there is a
small amount of clearance between bottom surfaces 16145 of bracket
16140 and surfaces 16139 of element cover 16130. Thus, when bracket
16140 is tightened down with screws 16142, a slight tension is
created effectively strapping thermistor 16030 and thermistor cover
16040 down with light pressure.
[0054] With this design, base 1000, element cover 1030, and bracket
1040 of the bimetal thermostat assembly of FIG. 3 could be common
to the base 16010, element cover 16130, and bracket 16140 of the
thermistor assembly and their fasteners could also be common. In
the thermistor assembly of FIG. 8, surfaces 16139 are at a suitable
elevation for fastening a bracket 16140 that holds down thermistor
cover 16040 and thermistor 16030. This elevation is the same as
that of surfaces 1037 in element cover 1030 in FIG. 3, which
cooperate with bracket 1040 to fasten down bimetal thermostat 1025.
The use of common components can reduce manufacturing cost.
[0055] A person skilled in the art might envision certain
variations of the embodiments. For example, the embodiment of FIG.
3 includes a base 1000, element cover 1030, a top cover 1050, and a
heat shield 1070. Some embodiments may omit the element cover and
mount the heat shield directly to the base by means of a heat
shield mounting bracket. Other embodiments may have an element
cover and mount the heat shield to the element cover, but omit the
top cover. As used herein, a base assembly for a carpet seaming
iron may include an iron base and any other components in the
carpet seaming iron that are directly or indirectly connected to
the iron base. FIG. 4 is an example of a base assembly including
the elements of the embodiment of FIG. 3.
[0056] Furthermore, the bracket 1040 of FIG. 3, which functions to
contact the top of bimetal thermostat 1025 to secure it to base
1000, might be included as an added feature on other of the
components. For example, a shape similar to bracket 1040 might be
formed as an integral bracket-like feature of a component similar
to element cover 1030, such that securing such an element cover to
the iron base causes its bracket-like feature to contact the top of
the bimetal thermostat to secure it to the base. Similarly, an
added bracket-like feature might be formed in a component similar
to top cover 1050, such that securing the top cover to a part like
element cover 1030 (or directly to the iron base) caused its
bracket-like feature to secure the bimetal thermostat to the base.
An added bracket-like feature might also be formed in a component
similar to heat shield 1070, such that securing the heat shield to
a part like element cover 1030 (or directly to the iron base)
caused its bracket-like feature to secure the bimetal thermostat to
the base. As used herein, a bimetal thermostat top cover may
include a component fastenable (as by other fastening components
which may couple it) to a portion of the base assembly to contact
the top surface of a bimetal thermostat to secure the bimetal
thermostat to the base assembly of a carpet seaming iron. Thus, a
bimetal thermostat top cover may a separate component, or it may be
an added feature of the element cover, top cover, or heat
shield.
[0057] Similarly, FIG. 8 includes a bracket 16140 that secures
thermistor cover 16040 and thermistor 16030 to base 16010. A shape
similar to bracket 16140 may be added to any of element cover
16130, a top cover such as top cover 1050 (FIG. 3), or a heat
shield such as heat shield 1070 (FIG. 3) to secure a thermistor
cover and thermistor to an iron base. As used herein, a thermistor
cover bracket may include a component fastenable (as by other
fasteners that couple it) to a portion of the base assembly to
contact a thermistor cover that secures a thermistor to the base
assembly of a carpet seaming iron.
[0058] The foregoing description of the embodiments of the
invention has been presented for the purpose of illustration; it is
not intended to be exhaustive or to limit the invention to the
precise forms disclosed. Persons skilled in the relevant art can
appreciate that many modifications and variations are possible in
light of the above disclosure. Finally, the language used in the
specification has been principally selected for readability and
instructional purposes, and it may not have been selected to
delineate or circumscribe the inventive subject matter. It is
therefore intended that the scope of the invention be limited not
by this detailed description, but rather by any claims that issue
on an application based hereon. Accordingly, the disclosure of the
embodiments of the invention is intended to be illustrative, but
not limiting, of the scope of the invention, which is set forth in
the following claims.
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