U.S. patent application number 16/431936 was filed with the patent office on 2019-10-24 for torch with integral flashback arrestor and thermal shut-off device.
The applicant listed for this patent is VICTOR EQUIPMENT COMPANY. Invention is credited to Nhyanh Duyet NGUYEN.
Application Number | 20190323709 16/431936 |
Document ID | / |
Family ID | 62709888 |
Filed Date | 2019-10-24 |
United States Patent
Application |
20190323709 |
Kind Code |
A1 |
NGUYEN; Nhyanh Duyet |
October 24, 2019 |
TORCH WITH INTEGRAL FLASHBACK ARRESTOR AND THERMAL SHUT-OFF
DEVICE
Abstract
A torch with integral flashback arrestor and thermal shut-off
device is provided. In one approach, a torch body includes a
passageway of the torch body, and a cartridge assembly disposed
within the passageway. The cartridge assembly may include at least
one of: a resettable pressure-sensitive device, and a thermal
shut-off device, wherein the pressure-sensitive device and the
thermal shut-off device are modifiable from a first configuration
to a second configuration in response to a pressure or temperature
gradient in the torch body, and wherein the second configuration
restricts flow through the passageway. The cartridge may further
include a check valve disposed along the passageway, for example,
within a bore of a bushing, or within a retainer coupled to the
torch body at an inlet of the passageway.
Inventors: |
NGUYEN; Nhyanh Duyet;
(Denton, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VICTOR EQUIPMENT COMPANY |
Denton |
TX |
US |
|
|
Family ID: |
62709888 |
Appl. No.: |
16/431936 |
Filed: |
June 5, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US2016/069392 |
Dec 30, 2016 |
|
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16431936 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23D 14/465 20130101;
F23D 14/825 20130101; F23N 5/247 20130101; F16K 17/383 20130101;
F23D 2900/14381 20130101; F23N 2231/28 20200101; F16K 17/164
20130101; F23D 14/82 20130101; F23N 2231/16 20200101; F23N 3/047
20130101; F23D 14/38 20130101; F23D 14/42 20130101; A62C 4/02
20130101; F23N 5/047 20130101; F16K 17/36 20130101; F16K 31/002
20130101; F23N 2241/11 20200101 |
International
Class: |
F23D 14/82 20060101
F23D014/82; F23D 14/46 20060101 F23D014/46 |
Claims
1. A torch body comprising: a passageway; and a cartridge assembly
disposed within the passageway, the cartridge assembly comprising:
at least one of: a resettable pressure-sensitive device, and a
thermal shut-off device, wherein the resettable pressure-sensitive
device and the thermal shut-off device are modifiable from a first
configuration to a second configuration in response to a pressure
or temperature gradient in the torch body, and wherein the second
configuration restricts flow of a gas through the passageway; a
bushing operable with at least one of: the pressure-sensitive
device and the thermal shut-off device; and a check valve
positioned along the passageway of the torch body, the check valve
operable with at least one of: the resettable pressure-sensitive
device or the thermal shut-off device.
2. The torch body of claim 1, wherein the bushing is a sintered
filter press fitted within a bore of the cartridge assembly.
3. The torch body of claim 1, the thermal shut-off device
comprising: a guide received within an internal bore of a bushing;
a stem positioned within an internal area of the guide; and an
adaptor separated from the stem by a thermal component, wherein the
adaptor has a plurality of openings through an end wall, and
wherein the second configuration causes the stem to engage the
adaptor to prevent flow of the gas through the plurality of
openings through the end wall.
4. The torch body of claim 3, the stem comprising: a first elongate
member extending from a first side of a sealing device and into an
internal area of the guide; and a second elongate member extending
from a second side of the sealing device and towards a central
opening of the adaptor.
5. The torch body of claim 3, wherein the guide includes a set of
openings formed through a sidewall.
6. The torch body of claim 3, the thermal shut-off device further
comprising a spring disposed within the stem for actuating the stem
towards the adaptor.
7. The torch body of claim 6, wherein the thermal component is one
of: a thermal plug made from a polymer configured to melt at a
predetermined temperature to bring the adaptor in contact with a
flange of the stem, and a resettable bi-metallic strip permitting
flow of the gas to the adaptor in the first configuration, and
permitting the spring to actuate the stem towards the adaptor in
the second configuration.
8. The torch body of claim 7, wherein the second elongate member
extends through the central opening of the adaptor in the case that
the thermal plug melts and the adaptor is brought into contact with
the sealing device of the stem.
9. The torch body of claim 1, wherein the resettable
pressure-sensitive device is a piston actuated in response to an
increase in back-flow pressure within the passageway.
10. The torch body of claim 1, wherein the check valve is disposed
within a retainer coupled to the torch body at an inlet of the
passageway.
11. The torch body of claim 1, wherein the check valve is disposed
within check is provided within a bore of the bushing.
12. A flashback arrestor comprising: a passageway of a torch body;
a resettable pressure-sensitive device disposed along the
passageway, wherein the resettable pressure-sensitive device is
modifiable from a first configuration to a second configuration in
response to a pressure change in the torch body, and wherein the
second configuration causes actuation of a piston within the
passageway to prevent back-flow through the passageway; and a check
valve disposed within the passageway.
13. The flashback arrestor of claim 12, the resettable
pressure-sensitive device comprising: an inner sleeve biased by an
inner spring; an outer sleeve biased by an outer spring; and a
locking ball positioned along an outer surface of a main body of
the piston within an opening of the inner sleeve, wherein a portion
of the locking ball extends into an opening between the inner
sleeve and the outer sleeve when the resettable pressure-sensitive
device is in the first configuration, and wherein the locking ball
extends into a groove of the main body when the pressure-sensitive
device is in the second configuration.
14. The flashback arrestor of claim 12, further comprising a
thermal shut-off device including: a guide received within an
internal bore of the passageway; a stem positioned within an
internal area of the guide; and an adaptor separated from the stem
by a thermal component, wherein the adaptor has a plurality of
openings through an end wall, and wherein the second configuration
causes the stem to engage the adaptor to prevent flow of a gas
through the plurality of openings through the end wall.
15. The flashback arrestor of claim 14, the stem comprising: a
first elongate member extending from a first side of a sealing
device and into an internal area of the guide; a spring disposed
within the first elongate member for actuating the stem towards the
adaptor; and a second elongate member extending from a second side
of the sealing device and towards a central opening of the
adaptor.
16. The flashback arrestor of claim 15, wherein the thermal
component is one of: a thermal plug made from a polymer configured
to melt at a predetermined temperature to bring the adaptor in
contact with a flange of the stem, and a resettable bi-metallic
strip permitting flow of the gas to the adaptor in the first
configuration, and permitting the spring to actuate the stem
towards the adaptor in the second configuration.
17. The flashback arrestor of claim 16, wherein the second elongate
member extends through the central opening of the adaptor in the
case that the thermal plug melts and the adaptor is brought into
contact with the sealing device of the stem.
18. A torch comprising: a torch body; and a flashback arrestor
disposed within a passageway of the torch body, the flashback
arrestor comprising: a thermal shut-off device modifiable from a
first configuration to a second configuration in response to a
temperature gradient in the torch body, wherein the second
configuration restricts flow of a gas through the passageway; a
retainer coupled to the torch body at an inlet of the passageway; a
bushing coupled to the retainer; and a check valve disposed within
the retainer.
19. The torch of claim 18, the thermal shut-off device comprising:
a guide received within an internal bore of the bushing; a stem
positioned within an internal area of the guide; and an adaptor
separated from the stem by a thermal component, wherein the adaptor
has a plurality of openings through an end wall, and wherein the
stem engages the adaptor to prevent flow of the gas through the
plurality of openings through the end wall in the second
configuration.
20. The torch of claim 19, the stem comprising: a first elongate
member extending from a first side of a sealing device and into an
internal area of the guide; a spring disposed within the first
elongate member for actuating the stem towards the adaptor; and a
second elongate member extending from a second side of the sealing
device and towards a central opening of the adaptor.
21. The torch of claim 20, wherein the thermal component is one of:
a thermal plug made from a polymer configured to melt at a
predetermined temperature to bring the adaptor in contact with the
sealing device of the stem, and a resettable bi-metallic strip
permitting a flow of gas to the adaptor in the first configuration,
and permitting the spring to actuate the stem towards the adaptor
in the second configuration.
22. The torch of claim 21, wherein the second elongate member
extends through the central opening of the adaptor in the case that
the thermal plug melts and the adaptor is brought into contact with
the sealing device of the stem.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/US2016/069392, filed on Dec. 30, 2016, the
entire contents of which is hereby incorporated by reference.
BACKGROUND OF THE DISCLOSURE
Field of the Disclosure
[0002] The present disclosure relates to cutting, welding, and
heating devices and, more particularly, to cutting torches with
flashback arrestors.
Discussion of Related Art
[0003] Oxygen-fuel cutting, welding, or heating devices discharge
fuel gas and oxygen from a nozzle for cutting, welding, or heating
purposes. A typical torch includes a control body for connecting to
separate fuel gas and oxygen supplies, tubes for supplying the
oxygen and fuel gas from the control body to a head, and a cutting
tip mounted to the head. The cutting tip receives the fuel gas and
oxygen from the head and discharges these gases from its nozzle.
More specifically, the head includes an interior surface extending
around and defining a head cavity, an oxygen port that is open to
the head cavity for supplying oxygen to the head cavity, and a fuel
gas port that is open to the head cavity for supplying fuel gas to
the head cavity. The cutting tip includes multiple passageways for
directing the gases from the head to the nozzle.
[0004] In one previous approach, a conventional cutting torch first
generates a preheat flame with gases discharged from the nozzle,
and the preheat flame is used to heat a metal workpiece. After the
preheat flame has heated the workpiece sufficiently, a high
velocity cutting oxygen stream is activated and delivered through
the nozzle. The high velocity cutting oxygen stream physically
removes molten material of the workpiece by oxidation, to cut the
workpiece. Typically, a number of valves and related components are
provided upstream of the nozzle, such as in the control body, to
control the operations of the cutting torch.
[0005] Flashback is regression of the flame through the torch
toward the gas supply, and can propagate through the torch and
welding hose. Flashback may be caused by mixed gases (e.g.,
fuel/oxygen) that are allowed to develop within the welding hose
due operator error, improper gas pressure, and/or defective
equipment. More specifically, in some cases, improper
procedure/operation can result in reverse flow of oxygen into the
fuel hose or reverse flow of fuel into the oxygen hose leading to
mixed gas (e.g., flammable gas) within either hose. Due to the
rapid and explosive nature of flashback, it poses a major safety
hazard to the operator of the gas torch and can damage the gas
torch and associated equipment.
[0006] Previous approaches for addressing flashback include the use
of a sintered material within the torch to be used at the entry
point of the gases into the torch. Although this stops the
flashback from traveling upstream from the components that supply
the gas to the torch, it disadvantageously does not eliminate the
effects of flashback within the torch itself. As a result, the
torch can still be damaged or the operator can be injured by
flashback within the torch.
[0007] In another previous approach, packing material may be
installed into the head of a torch or in a tube that is immediately
upstream from the head for arresting flashback. However, this
packing material may become damaged, such as by becoming clogged
with carbon deposits resulting from flashback. As a result, the
packing material must be periodically replaced. Disadvantageously,
the removal and replacement of packing material in cutting torches
is labor intensive. Additionally, and of significant safety
importance, if the packing material is not properly packed it may
not perform its intended function, which can result in damage to
the torch or injury to its operator.
[0008] In yet another previous approach, a check valve may be
installed in each of the oxygen and fuel passageways to allow the
oxygen and the fuel to flow in one direction, while preventing the
reverse flow. Check valves, however, are mechanical devices that
may become unreliable when contaminated with dirt or debris, which
can cause the check valve to leak. Moreover, the check valves
cannot prevent flashback flame from propagating upstream once
flashback occurs.
SUMMARY OF THE DISCLOSURE
[0009] In an exemplary approach according to the disclosure, a
torch body may include a passageway, and a cartridge assembly
disposed within the passageway. The cartridge assembly may include
at least one of: a resettable pressure-sensitive device, and a
thermal shut-off device, wherein the pressure-sensitive device and
the thermal shut-off device are modifiable from a first
configuration to a second configuration in response to a pressure
or temperature gradient in the torch body, and wherein the second
configuration restricts flow of a gas through the passageway. The
cartridge assembly may further include a bushing operable with at
least one of: the pressure-sensitive device and the thermal
shut-off device, and a check valve positioned along the passageway
of the torch body, the check valve operable with at least one of:
the resettable pressure-sensitive device or the thermal shut-off
device.
[0010] In another exemplary approach of the disclosure, a flashback
arrestor may include a passageway of a torch body and a resettable
pressure-sensitive device operable with the bushing, wherein the
resettable pressure-sensitive device is modifiable from a first
configuration to a second configuration in response to a pressure
change in the torch body, and wherein the second configuration
causes actuation of a piston within the passageway to prevent
back-flow through the passageway. The flashback arrestor may
further include a check valve disposed within the passageway.
[0011] In another exemplary approach of the disclosure, a torch may
include a torch body and a flashback arrestor disposed within a
passageway of the torch body. The flashback arrestor may include a
thermal shut-off device modifiable from a first configuration to a
second configuration in response to a temperature gradient in the
torch body, wherein the second configuration restricts flow of a
gas through the passageway. The flashback arrestor may further
include a retainer coupled to the torch body at an inlet of the
passageway, a bushing coupled to the retainer, and a check valve
disposed within the retainer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings illustrate exemplary approaches of
the disclosed torch handle including a torch and flashback arrestor
so far devised for the practical application of the principles
thereof, and in which:
[0013] FIG. 1 is a side partial cutaway view of a flashback
arrestor mounted within a torch body according to exemplary
approaches of the disclosure;
[0014] FIG. 2 is a perspective view of the flashback arrestor of
FIG. 1 according to exemplary approaches of the disclosure;
[0015] FIG. 3 is an exploded perspective view of the flashback
arrestor of FIG. 2 according to exemplary approaches of the
disclosure;
[0016] FIG. 4 is a side perspective view of a stem and adaptor of
the flashback arrestor of FIG. 2 according to exemplary approaches
of the disclosure;
[0017] FIG. 5 is side cutaway view of the flashback arrestor of
FIG. 1 according to exemplary approaches of the disclosure;
[0018] FIG. 6 is a side partial cutaway view of a flashback
arrestor mounted within a torch body according to another exemplary
approach of the disclosure;
[0019] FIG. 7 is perspective view of a resettable
pressure-sensitive device within the torch body of FIG. 6 according
to exemplary approaches of the disclosure;
[0020] FIG. 8 is a partial cutaway side view of the resettable
pressure-sensitive device of FIG. 7 in a first configuration
according to exemplary approaches of the disclosure; and
[0021] FIG. 9 is a partial cutaway side view of the resettable
pressure-sensitive device of FIG. 7 in a second configuration
according to exemplary approaches of the disclosure.
[0022] The drawings are not necessarily to scale. The drawings are
merely representations, not intended to portray specific parameters
of the disclosure. Furthermore, the drawings are intended to depict
exemplary embodiments of the disclosure, and therefore is not
considered as limiting in scope.
[0023] Furthermore, certain elements in some of the figures may be
omitted, or illustrated not-to-scale, for illustrative clarity. The
cross-sectional views may be in the form of "slices", or
"near-sighted" cross-sectional views, omitting certain background
lines otherwise visible in a "true" cross-sectional view, for
illustrative clarity. Furthermore, for clarity, some reference
numbers may be omitted in certain drawings.
DESCRIPTION OF EMBODIMENTS
[0024] The present disclosure will now proceed with reference to
the accompanying drawings, in which various approaches are shown.
It will be appreciated, however, that the disclosed torch and
flashback arrestor may be embodied in many different forms and
should not be construed as limited to the approaches set forth
herein. Rather, these approaches are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the disclosure to those skilled in the art. In the
drawings, like numbers refer to like elements throughout.
[0025] As used herein, an element or operation recited in the
singular and proceeded with the word "a" or "an" should be
understood as not excluding plural elements or operations, unless
such exclusion is explicitly recited. Furthermore, references to
"one approach" or "one embodiment" of the present disclosure are
not intended to be interpreted as excluding the existence of
additional approaches and embodiments that also incorporate the
recited features.
[0026] Furthermore, spatially relative terms, such as "beneath,"
"below," "lower," "central," "above," "upper," "proximal,"
"distal," and the like, may be used herein for ease of describing
one element's relationship to another element(s) as illustrated in
the figures. It will be understood that the spatially relative
terms may encompass different orientations of the device in use or
operation in addition to the orientation depicted in the
figures.
[0027] As disclosed herein, embodiments of the disclosure provide a
torch with integral flashback arrestor and thermal shut-off device.
In some approaches, a torch body includes a passageway of the torch
body, and a cartridge assembly disposed within the passageway. The
cartridge assembly may include a number of different arrangements.
For example, in one arrangement, the cartridge assembly may include
a thermal shut-off combined with a flashback arrestor (e.g., a
sintered filter/bushing) and, optionally, a check valve. In a
second arrangement, the cartridge assembly may include a pressure
sensitive switch combined with a check valve and, optionally, a
flashback arrestor. In a third arrangement, the cartridge assembly
may include a thermal shut off combined with a flashback arrestor,
a pressure sensitive switch, and a check valve.
[0028] As a result, embodiments of the disclosure provide a
built-in design that makes the torch inoperable without the thermal
shut-off device and filter element/bushing or, alternatively,
without the resettable pressure-sensitive device and the check
valve. The torch utilizes a parts-in-place principle in which,
unlike prior approaches, a user may be unable to operate the torch
without the safety features in place. Thus, the built-in design
offers additional security and safety.
[0029] Referring now to FIG. 1, a torch body of a torch according
to exemplary embodiments will be described in greater detail. As
shown, the torch body 100 defines an oxygen passageway 102 and a
fuel gas passageway 104, wherein the oxygen passageway 102 is
configured to receive a flow of oxygen and the fuel gas passageway
104 is configured to receive a flow of gas during operation of the
torch 101 (partially shown). Hereinafter, embodiments of the
disclosure will only be discussed with respect to the oxygen side
of the torch body for the sake of brevity. However, it will be
appreciated that the fuel side may have identical components but
with left-hand threads instead of right-hand threads.
[0030] Shown within the oxygen passageway 102 is a flashback
arrestor (FBA) 110 provided to stop a flashback within the torch
body 100, as will be described in greater detail herein. The FBA
110 may include a cartridge assembly 112 disposed within the oxygen
passageway 102 of the torch body 100 via a retainer 116, which is
coupled to the torch body 100, e.g., by a distal threaded portion
118. In some embodiments, the retainer 116 may be held in place by
a retaining plate (not shown), which may be secured to the torch
body 100 by a screw and lock washer, for example. The retainer 116
may house therein a check valve 120 at an inlet of the oxygen
passageway 102.
[0031] With reference now to FIGS. 1-3, the FBA 110 according to
exemplary embodiments of the disclosure will be described in
greater detail. As shown, the FBA 110 includes a porous or sintered
metal filter 124 coupled to the retainer 116, for example, by a
press-fit. The retainer 116 includes a bore 126 receiving the check
valve 120, the bore 126 in fluid communication with an inlet of the
oxygen passageway 102. The retainer 116 includes a proximal
threaded portion 130 and the distal threaded portion 118. The check
valve 120 is disposed in the bore 126 proximate the proximal
threaded portion 130. The proximal threaded portion 130 has an
outside diameter and functions as a hose connector for connecting
to an oxygen hose (not shown). The check valve 120 is open during
normal operation of the torch, allowing oxygen to flow from the
hose through the check valve 120 through the torch to the cutting
tip. If a reverse flow situation develops, the check valve 120 is
designed to close, in most instances, to reduce the possibility of
reverse flow of gas from the torch handle into the hose.
[0032] As shown, the distal threaded portion 118 of the retainer
116 engages an inner surface of the torch body 100, for example, a
threaded surface 119, to secure the flashback arrestor 110 to the
torch body 100. In some embodiments, the distal threaded portion
118 has an outside diameter greater than the outside diameter of
the proximal threaded portion 130. Furthermore, in some
embodiments, an O-ring 132 is disposed in an annular groove 134 of
the retainer 116 to prevent leakage of gas from the oxygen
passageway to outside the flashback arrestor 110 when the retainer
116 is installed in the torch body 100.
[0033] In exemplary embodiments, the sintered filter 124 of the
flashback arrestor 110 is, in one form, a porous cylindrical body
or bushing, and is formed by a sintering process. The sintered
filter 124 defines a proximal end portion 135, a distal end portion
136, and a bore 138 extending therebetween. The bore 138 of the
sintered filter 124 is in fluid communication with the bore 126 of
the retainer 116. The sintered filter 124 may be press-fitted into
the retainer 116 proximate the distal threaded portion 118 at the
distal end of the retainer 116. In exemplary embodiments, the
sintered filter 124 defines a plurality of pores, wherein the bore
138 of the sintered filter 124 is in fluid communication with the
oxygen passageway 102 through the pores of the sintered filter 124.
The pores may have irregular shapes and define passageways through
the porous sintered filter 124 for extinguishing a flashback
through the torch body 100.
[0034] Referring now to FIGS. 2-5, the FBA 110 according to
exemplary embodiments will be described in greater detail. As
shown, the FBA 110 further includes a thermal shut-off device 140
modifiable from a first configuration to a second configuration in
response to a pressure and/or temperature gradient in the torch
body 100 so as to restrict flow of a fluid through the oxygen
passageway 102 of the torch 101. In some embodiments, the thermal
shut-off device 140 includes a thermally reactive component, such
as a thermal plug or a resettable bi-metallic strip, which changes
state in response to a temperature gradient (e.g., a rapid increase
caused by a flashback) to permit or restrict the flow of oxygen
through the oxygen passageway 102 (FIG. 1).
[0035] As shown, the thermal shut-off device 140 may include an
adaptor 148 having a plurality of openings 142 and a central
opening 144 formed through an end wall 146 thereof, the plurality
of openings 142 permitting oxygen to flow from the adaptor 148
during normal operation. The adaptor 148 is configured to engage a
guide 152 of the thermal shut-off device 140 such that a first
section 154 of the adaptor 148 abuts a rim 156 of the guide 152,
and a second section 158 of the adaptor 148 extends into an
internal area 160 of the guide 152. The guide 152 may have a
generally frusto-conical shaped first section 161 and a generally
cylindrical shaped second section 163, wherein the second section
163 is configured to extend within the bore 138 of the sintered
filter 124. The first section 161 of the guide 152 further includes
a flange 151 having an O-ring 153 extending around a circumference
thereof.
[0036] The thermal shut-off device 140 may further include a stem
162 and a spring 157 positionable within the internal area 160 of
the guide 152. In some embodiments, the stem 162 includes a sealing
device 164, such as a flange 165 with groove/O-ring 166, separating
first and second elongate members 167, 168. As shown, the first
elongate member 167 may be a cylindrical element extending from a
first side of the sealing device 164 and into the internal area 160
of the guide 152, and the second elongate member 168 may be a
cylindrical element extending from an opposite side of the sealing
device 164 towards the central opening 144 of the adaptor 148. A
thermal component 170 may be formed around the second elongate
member 168 for separating the adaptor 148 from the stem 162 under
normal operating conditions. In some non-limiting embodiments, a
diameter of the first elongate member 167 is greater than a
diameter of the second elongate member 168.
[0037] During normal operating conditions, the adaptor 148 is
separated from the stem 162 by the thermal component 170, which is
present around the second elongate member 168 of the stem 162 in
the first configuration of the thermal shut-off device 140. In some
embodiments, the thermal component 170 is a polymer (e.g., plastic)
or a lead plug having a pre-specified melting point to allow the
thermal component 170 to melt in response to a high temperature
event within the torch head 100, such as sustained backfire. Once
melted, the thermal shut-off device 140 enters the second
configuration in which the stem 162 is permitted to engage the
adaptor 148 in response to a force from the spring 157, thereby
preventing flow of a gas through the plurality of openings 142 of
the adaptor 148.
[0038] In other embodiments, the thermal component 170 is an
elastic or resettable bi-metallic strip designed in such a way that
in a normal position it keeps the flow passages open, but when
actuated allows the spring force of the sealing mechanism to close
the flow passage. In some embodiments, the bi-metallic strip
expands in response to a higher temperatures, thus separating
itself from the first elongate member 167 and allowing the stem 162
to engage the adaptor 148 in response to a force from the spring
157. The second elongate member 168 then moves into the central
opening 144, which prevents flow of a fluid through the plurality
of openings 142 of the adaptor 148. As the bi-metallic strip cools
down and contracts, it forces the stem 162 away from the adaptor
148, thus allowing gas to again flow through the plurality of
openings 142 of the adaptor 148.
[0039] Turning now to FIG. 5, a cross-sectional view of the thermal
shut-off device 140 will be described in greater detail. As shown,
the thermal shut-off device 140 may be inserted into a cavity 172
of the oxygen passageway 102 of the torch body 100 until the
adaptor 148 makes contact with an end wall 173 defining a distal
portion of the cavity 172. The first section 154 of the adaptor 148
may have a diameter greater than that of the second section 158 of
the adaptor 148, thus causing the first section 154 of the adaptor
148 to engage the rim 156 of the first section 161 of the guide
152, and allowing the second section 158 of the adaptor 148 to
extend into the guide 152.
[0040] In exemplary embodiments, the O-ring 153 of the first
section 161 of the guide 152 forms a seal with an inner sidewall
175 of the cavity 172. The guide 152 includes the plurality of
openings 150 formed through a sidewall of the first section 161,
thereby allowing flow between the internal area 160 of the guide
152 and a fluid channel 177, which is defined by the O-ring 153,
the sintered filter 124, and the retainer 116, shown threaded into
the torch body 100. A shoulder 178 defining the intersection of the
first and second sections 161, 163 of the guide 152, may be in
abutment with a distal end surface 179 of the sintered filter 124,
as shown.
[0041] The second section 163 of the guide 152 extends within the
bore 138 of the sintered filter 124, and includes a proximal end
wall 180, a first sidewall section 181, and a second sidewall
section 182. A sloped wall 183 extending between the first sidewall
section 181 and the second sidewall section 182 is configured to
engage the flange 165 of the stem 162 to limit movement of the stem
162 in a proximal direction towards the retainer 116. The O-ring
166 of the stem 162 engages an inner surface of the first sidewall
section 181 to form a seal therebetween.
[0042] In some embodiments, the spring 157 is provided within an
interior 184 of the stem 162, and engages the proximal end wall
180. During use, the spring 157 presses against the flange 165 of
the stem 162, which in turn presses against the adaptor 148 via the
thermal component 170. Specifically, the thermal component 170 and
the second elongate member 168 are biased towards the central
opening 144 of the adaptor 148. When present, the thermal component
170 separates the stem 162 from the adaptor 148, thereby preventing
the second elongate member 168 from extending fully into the
central opening 144 of the adaptor 148. In the event of an
increased temperature occurs within the torch body 100, the thermal
component 170 is designed to melt, thus causing the thermal
shut-off device 140 to transform to the second configuration (not
shown) in which the second elongate member 168 is permitted to
enter the central opening 144 and extend into a cavity 186 beyond
the distal end of the adaptor 148. This causes a distal end surface
190 of the flange 165 of the stem 162 to cover the plurality of
openings 142 through the adaptor 148, and the O-ring 166 of the
stem 162 to move from a first position against the inner surface of
the first sidewall section 181, as shown, to a second position
against an inner sidewall surface 191 of the second section 158 of
the adaptor 148. The O-ring 166 creates a seal with the inner
sidewall surface 191, thereby preventing flow of gas through the
plurality of openings 142 of the adaptor 148, and disabling the
torch 101.
[0043] Although not shown, it will be appreciated that in another
embodiment, the thermal shut-off device 140 is a solenoid valve in
communication with an electronic switch. The solenoid valve may be
disposed within the torch body 100, and the electronic switch is
configured to send a signal to close the solenoid valve in the case
a sensor operable with the electronic switch detects a flow of
electrons above a predetermined temperature. The electronic switch
may function in a similar fashion to the adaptor and stem described
herein, but instead of a mechanical interface for preventing flow,
the electronic switch senses the flow of electrons using, e.g., a
thermocouple or thermopile, and sends a signal to shut down the
solenoid valve provided in the torch flow path. Once the
temperature has decreased, the electronic switch senses a reduced
flow of electrons, causing the valve to reopen.
[0044] Referring now to FIGS. 6-9, a resettable pressure sensitive
device within a torch body 200 according to exemplary embodiments
of the disclosure will be described. As shown, the torch 201
includes many of the features previously described in relation to
the torch 101 shown in FIG. 1 and, as such, may not be described in
detail hereinafter for the sake of brevity. In this embodiment, the
torch body 200 may include a resettable pressure sensitive device
(PSD) 241, such as a piston actuable in response to a back-flow
pressure increase within the oxygen passageway 202. In one
embodiment, the PSD 241 is secured within the oxygen passageway 202
of the torch body 200 via a retainer 216, which is coupled to the
torch body 200, e.g., by a proximal threaded connection 218. In
some embodiments, the retainer 216 may be held in place by a
retaining plate (not shown), which may be secured to the torch body
200 by a screw and lock washer, for example.
[0045] As shown, the PSD 241 includes a main body 243, which may be
a piston, having a first O-ring 245 and a second O-ring 247
extending around a circumference thereof and engaging an inner
sleeve 249. The main body 243 and an outer sleeve 285 are biased
towards a distal end 239 by an inner spring 287 and an outer spring
289, respectively. In some embodiments, a distal end 244 of the
main body 243 extends into the proximal end portion 235 of the
sintered filter 224. A proximal end 237 of the PSD 241 may include
external threading 255 (FIG. 6) for engaging a hose (not shown),
while the distal end 239 of the PSD 241 may couple to the torch
body 200 via the retainer 216 and threading 219, or be coupled
directly to the torch body 200 via a threaded connection in the
case no retainer is present.
[0046] In a first configuration, i.e., during normal operation, one
or more locking balls 293 are maintained along an outer surface 294
of the main body 243 within an opening 295 of the inner sleeve 249,
for example, as best shown in FIG. 7. In some embodiments, a
portion of the locking ball 293 may extend into an opening 296
between the inner sleeve 249 and the outer sleeve 285. In the event
of a flashback, represented by a reverse gas flow 297 shown in
FIGS. 8-9, the flashback forces the main body 243 towards the
proximal end 237, thus compressing the inner spring 287 and causing
the locking ball 293 to enter a recess or groove 298 of the main
body 243. As shown, as the locking ball 293 moves into the groove
298 and away from the opening 296 between the inner sleeve 249 and
the outer sleeve 285, the outer sleeve 285 is permitted to move
towards the distal end 239 by a force from the outer spring 289.
The locking ball 293 is therefore confined to the groove 298 by the
outer sleeve 285 and the sidewalls of the opening 295 of the inner
sleeve 249. Once in place, the locking ball 293 prevents movement
of the main body 243 relative to the inner sleeve 249, ceasing gas
flow through the PSD 241. In some embodiments, the PSD 241 remains
in the closed, second configuration until manually reset by an
operator, for example by sliding the outer sleeve 285 towards the
proximal end 237, which allows the locking ball 293 to move into
the opening 296 and out of the groove 298, thus permitting the main
body 243 to move towards the distal end 239.
[0047] In some embodiments, a check valve 220, which is designed to
allow flow in only one direction, is provided along the oxygen
passageway 202 of the torch body 200, for example, within the bore
238 of the sintered filter 224. The check valve 220 is typically
open during normal operation of the torch 101, allowing oxygen to
flow from the hose through the check valve 220, through the torch
201, and to the cutting tip. If a reverse flow situation develops,
the check valve 220 is designed to close, for example, by engaging
the distal end 244 of the main body 243, thus reducing the
possibility of reverse flow of gas. In exemplary embodiments, the
check valve 220 is positioned between the thermal shut-off device
240 and the PSD 141. As shown, the check valve may 220 abut the
proximal end wall 280 of the second section 263 of the guide 252,
which extends within the bore 238 of the sintered filter 224.
[0048] While the present disclosure has been described with
reference to certain approaches, numerous modifications,
alterations and changes to the described approaches are possible
without departing from the sphere and scope of the present
disclosure, as defined in the appended claims. Accordingly, it is
intended that the present disclosure not be limited to the
described approaches, but that it has the full scope defined by the
language of the following claims, and equivalents thereof. While
the disclosure has been described with reference to certain
approaches, numerous modifications, alterations and changes to the
described approaches are possible without departing from the spirit
and scope of the disclosure, as defined in the appended claims.
Accordingly, it is intended that the present disclosure not be
limited to the described approaches, but that it has the full scope
defined by the language of the following claims, and equivalents
thereof.
* * * * *