US20120017574A1

US20120017574A1 - Strap for securing exhaust treatment device

Info

Publication number: US20120017574A1
Application number: US12/840,126
Authority: US
Inventors: Saad Hasan; Faiz Mohammed Ibrahim Khan; Dongming Tan; Thomas Victor Staley; Richard Anderson Crandell; Paul F. Olsen; Randy Lee Marquis; Christine Annette Kohrman; Jianxi Zhu
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2010-07-20
Filing date: 2010-07-20
Publication date: 2012-01-26
Also published as: CN102337955A

Abstract

A strap for securing an exhaust treatment device is disclosed. The strap may have a coupler on a first end and a loop on a second end. The loop may include an inner portion, a curved portion, and an outer portion of the strap. The outer portion of the strap may be secured to the inner portion of the strap at a point of securement to form the loop. The outer portion may form an angle with respect to the inner portion that is no greater than about 10 degrees as the outer portion diverges from abutting the inner portion.

Description

TECHNICAL FIELD

The present disclosure relates generally to a strap, and more particularly, to a strap for securing an exhaust treatment device in an emissions control system.

BACKGROUND

In order to comply with emission standards, machine manufactures have developed and implemented a variety of exhaust treatment devices to reduce pollutants in exhaust gas prior to the exhaust gas being released into the atmosphere. The exhaust treatment devices may include, for example, a diesel particulate filter, a selective catalytic reduction device, a diesel oxidation catalyst, a fuel-fired burner for regeneration of the diesel particulate filter, a muffler, and other similar components.
Due to the increasing complexity and number of exhaust treatment devices, and the small amount of available space, manufacturers have mounted several exhaust treatment devices together on a single structure or cradle. However, securing exhaust treatment devices in a cradle in a reliable manner has proven difficult.
One method for securing exhaust treatment devices in a casing is disclosed in U.S. Pat. No. 2,279,090 (the '090 patent) to Markey. Specifically, the '090 patent discloses an exhaust manifold support clamp. The clamp comprises a strip of metal that is bent back on itself to form an eye. A pin is rotatably mounted in the eye. The pin has an enlarged portion confined in a slot. The enlarged portion prevents endwise movement of the pin and is threaded for the reception of a T-shaped hinge member.
Although the device of the '090 patent may secure an exhaust manifold, the '090 device may have limitations. For example, the '090 device may have high stress concentrations at the eye, thus potentially leading to premature failure of the device.
The disclosed device is directed to overcoming one or more of the problems set forth above and/or other problems in the art.

SUMMARY OF THE DISCLOSURE

In one aspect, the present disclosure is directed to a strap for securing an exhaust treatment device. The strap comprises a coupler on a first end and a loop on a second end. The loop includes an inner portion, a curved portion, and an outer portion of the strap. The outer portion of the strap is secured to the inner portion of the strap at a point of securement to form the loop. The outer portion forms an angle with respect to the inner portion that is no greater than about 10 degrees as the outer portion diverges from abutting the inner portion.
In another aspect, the present disclosure is directed to a strap for securing an exhaust treatment device, including a first strap member including a coupler on a first end and a loop on a second end. The strap also includes a second strap member. The second strap member includes a coupler on a first end configured to couple with the coupler of the first strap member. The second strap member also includes a loop on a second end. The loop includes a flexible band of material that is looped and secured to itself at a point of securement. A loop length is no less than one third of an effective length of the strap. The effective length is defined as a distance from an end of the loop of the first strap member to an end of the loop of the second strap member when the coupler of the first strap member is coupled to the coupler of the second strap member. The loop length is defined as a distance from an end of the loop of the second strap member to the point of securement.
In yet another aspect, the present disclosure is directed to an exhaust treatment system. The system includes a cradle and an exhaust treatment device situated in the cradle. The system also includes a strap passing around at least a portion of the exhaust treatment device to secure the exhaust treatment device to the cradle. The strap includes a first loop on a first end of the strap connected to the cradle and a second loop on a second end of the strap connected to the cradle. The second loop includes a flexible band of material being looped and secured to itself at a point of securement. A loop length is no less than one third of an effective length of the strap. The effective length is defined as a distance from an end of the first loop to an end of the second loop. The loop length is defined as a distance from the end of the second loop to the point of securement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of a power system including an emissions control system;

FIG. 2 is an exploded view of the emissions control system of FIG. 1;

FIG. 3 is a diagrammatic illustration of a first bracket of an emissions control system;

FIG. 4 is a diagrammatic illustration of a strap for an emissions control system;

FIG. 5 is a side view of a first strap member;

FIG. 6 is a side view of a second strap member;

FIG. 7 is a diagrammatic illustration of pivoting members for use with an emissions control system; and

FIG. 8 is a diagrammatic illustration of the pivoting members of FIG. 7.

DETAILED DESCRIPTION

FIG. 1 illustrates a diagrammatic representation of a power system 10, which may include a power source 12 and an exhaust system 14. Power source 12 may embody a combustion engine, such as, for example, a diesel engine, a gasoline engine, a gaseous fuel-powered engine (e.g., a natural gas engine), or any other type of combustion engine known to one skilled in the art.
Exhaust system 14 may direct exhaust from power source 12 via an exhaust conduit 23 to an emissions control system 16. After passing through emissions control system 16, the exhaust may be directed to the atmosphere. Emissions control system 16 of exhaust system 14 may be configured to monitor, control, and/or modify exhaust emissions. Emissions control system 16 may include one or more exhaust treatment devices 22 and a cradle 26.
Exhaust treatment devices 22 may be devices configured to reduce emissions of harmful gasses, particulate matter, and/or noise emitted from power source 12. Each exhaust treatment device 22 may embody, for example a diesel oxidation catalyst (DOC), a particulate filter (PF or DPF), a selective catalytic reduction (SCR) device, a lean NOx trap (LNT), a muffler, a regeneration device, a reductant mixing device, or any other exhaust treatment device known in the art. It is contemplated that each exhaust treatment device 22 may also comprise a combination of exhaust treatment devices, such as, for example, a combination of a DOC and a DPF; a combination of a catalyst and a DPF (i.e., a CDPF); a combination of a DOC, a DPF, and an SCR; or other combinations known in the art.
As shown in FIG. 2, cradle 26 may be a device configured to support multiple exhaust treatment devices 22 using a single structure. Specifically, cradle 26 may secure exhaust treatment devices 22 in a compact configuration. Cradle 26 may include a first bracket 28 and a second bracket 30. First bracket 28 and second bracket 30 may be oriented parallel but spaced apart from each other. First bracket 28 may couple to second bracket 30 using one or more rigid cross members 32. Cross members 32 may attach to first and second brackets 28 and 30 via mechanical fasteners (e.g., bolts, screws, rivets, etc.), welding, brazing, or any other joining process known in the art. Alternatively, first bracket 28, second bracket 30, and cross members 32 may be formed using a single casting.
Each of first and second brackets 28 and 30 may include a first support surface 34. First support surface 34 of first bracket 28 and first support surface 34 of second bracket 30 may support each end of a first exhaust treatment device 36. Each of first and second brackets 28 and 30 may also include a second support surface 38. Second support surface 38 of first bracket 28 and second support surface 38 of second bracket 30 may support each end of a second exhaust treatment device 40. In addition to connecting first and second brackets 28 and 30, one or more of cross members 32 may support a middle portion of first exhaust treatment device 36 and/or second exhaust treatment device 40.
It is contemplated that a geometry of first support surface 34 may be shaped to match an outer geometry of first exhaust treatment device 36 and a geometry of second support surface 38 may be shaped to match an outer geometry of second exhaust treatment device 40. For example, when first and second exhaust treatment devices 36 and 40 are shaped as canisters, first and second support surfaces 34 and 38 may have generally arcuate surfaces with substantially the same radii of curvature as first and second exhaust treatment devices 36 and 40, respectively.
As seen in FIG. 1, one or more straps 46 may pass over exhaust treatment devices 22 and secure exhaust treatment devices 22 to cradle 26. Specifically, straps 46 may pass around at least portion of an outer periphery of exhaust treatment devices 22. Each strap 46 may be composed of a flexible band of material. Strap 46 may be composed of, for example, metal, rubber, composite, polymer or any other appropriate material known in the art. In one embodiment, strap 46 may be composed of thin steel.
As shown in FIG. 3, straps 46 may couple to different sides of first bracket 28 and/or second bracket 30. Each strap 46 may include a first strap member 50 and a second strap member 52. First strap member 50 and second strap member 52 may couple together at a junction 54. First strap member 50 and second strap member 52 may each include a plurality of couplers 56. Each coupler 56 may fasten an end of first strap member 50 and/or second strap member 52 to another object.
Each coupler 56 may comprise, for example, a ratchet, a loop, a buckle, a hitch, a hook, or any other appropriate type of coupler or fastener known in the art. In an exemplary embodiment, one coupler 56 of first strap member 50 may comprise a loop 58 securing a threaded fastener 60 on a first end 62 of first strap member 50. Another coupler 56 of first strap member 50 may comprise a loop 64 located on a second end 66 of first strap member 50. Second strap member 52 may also include one or more couplers 56, and more specifically, a loop 68 with a threaded fastener 70 located on a first end 72 of second strap member 52 and a loop 74 located on a second end 76 of second strap member 52.
As shown in FIG. 4, loop 58 and loop 68 may each include a slot 78. Each slot 78 may run parallel to a longitudinal dimension of first strap member 50 and second strap member 52, thus bifurcating each of loop 58 and loop 68. It is contemplated that threaded fastener 60 may be situated in slot 78 of loop 58 and threaded fastener 70 may be situated in slot 78 of loop 68. Each of threaded fasteners 60 and 70 may comprise a T-shaped member. Each bifurcated side of loop 58 may pass over a portion of the cross-member of the “T” of threaded fastener 60, thus securing threaded fastener 60 to first strap member 50. Similarly, each bifurcated side of loop 68 may pass over a portion of the cross-member of the “T” of threaded fastener 70, thus securing threaded fastener 70 to second strap member 52.
Threaded fastener 60 may mate with threaded fastener 70 at junction 54 in order to secure first strap member 50 to second strap member 52. It is contemplated that threaded fastener 70 may be a male threaded fastener while threaded fastener 60 may be a female threaded fastener configured to receive the male fastener. Alternatively, the female and male relationship of threaded fasteners 60, 70 may be reversed. At least one of threaded fastener 60 or threaded fastener 70 may be rotatable, thus allowing first and second strap members 50, 52 to be tightened around exhaust treatment device 22.
Referring to FIGS. 5 and 6, loop 64 may connect first strap member 50 to cradle 26. Specifically, a pin 80 (see also FIG. 3) may pass through loop 64 to secure first strap member 50 to cradle 26. Loop 64 may be formed by looping the flexible band of material of first strap member 50 backward and attaching it to itself at a point of securement 82. In some embodiments, loop 64 may have a teardrop shape comprising an inner portion 84, a curved portion 86, and an outer portion 88 of first strap member 50. Outer portion 88 of first strap member 50 may be secured to inner portion 84 of first strap member 50 at point of securement 82 to form the teardrop shape. Inner portion 84 Outer portion 88 and inner portion 84 may be secured via mechanical fastening, welding, or any other appropriate method.
It is contemplated that loop 74 of second strap member 52 may be substantially similar to loop 64. In other words, loop 74 may secure second strap member 52 to cradle 26 via a pin 80. Loop 74 may also be formed by looping the flexible band of material of second strap member 52 backward and attaching it to itself at a point of securement 90. Specifically, loop 74 may formed by attaching an inner portion 92 to an outer portion 96 at point of securement 90. Like loop 64, loop 74 may have a tear-drop shape. Inner portion 92 may attach to outer portion 96 via mechanical fastening, welding, or any other appropriate method.
It is contemplated that first strap member 50 may be composed of a single piece of flexible material that is looped and secured to itself a first time to create loop 64 and looped and secured to itself a second time to create loop 58. Similarly, second strap member 52 may be composed of a single piece of flexible material that is looped and secured to itself a first time to create loop 74 and looped and secured to itself a second time to create loop 68. On second strap member 52, the point of securement for loop 68 and point of securement 90 for loop 74 may be approximately the same location on second strap member 52. Second strap member 52 may also have a tongue 61 that may pass under first strap member 50 when threaded fastener 60 is mated with threaded fastener 70.
Strap 46 may have an effective length 100. Effective length 100 may be defined as a distance along strap 46 from an end of loop 64 (i.e., curved portion 86) to an end of the loop 74 (i.e., curved portion 94) when threaded fastener 60 is mated with threaded fastener 70. First strap member 50 may also have a loop length 101. Loop length 101 for loop 64 may be defined as a distance along first strap member 50 from curved portion 86 to point of securement 82. Similarly, loop length 101 for loop 74 may be defined as a distance along second strap member 52 from curved portion 94 to point of securement 90. It is contemplated that loop length 101 for each of first strap member 50 and second strap member 52 may be no less than one third of effective length 100. In some embodiments, loop length 101 for each of first strap member 50 and second strap member 52 may be one third of effective length 100.
Referring to loop 64, outer portion 88 may form an angle (3 with respect to inner portion 84 that is no greater than about 10 degrees as outer portion 88 diverges from abutting inner portion 84. Similarly, referring to loop 74, outer portion 96 may form an angle a with respect to inner portion 92 that is no greater than about 10 degrees as outer portion 96 diverges from abutting inner portion 92. In some embodiments, a and may be between about 8-10 degrees.
At least one end of strap 46 may couple to pin 80 at a radial distance away from an outer surface of exhaust treatment device 22. Starting at pin 80, first strap member 50 may pass above the outer surface of exhaust treatment device 22 until it contacts the outer surface at a tangent point 102. At tangent point 102, first strap member 50 may be substantially tangent to the surface of exhaust treatment device 22. It is contemplated that a distance along first strap member 50 from tangent point 102 to point of securement 82 may be no less than about two inches (50.8 mm). It is contemplated that outer portion 88 and inner portion 84 may be substantially straight from tangent point 102 to curved portion 86.
Similarly, it is contemplated that second strap member 52 may pass above the outer surface of exhaust treatment device 22 until it contacts the outer surface at tangent point 104. At tangent point 104, second strap member 52 may be substantially tangent to the surface of exhaust treatment device 22. It is contemplated that a distance along second strap member 52 from tangent point 104 to point of securement 90 may be no less than about two inches (50.8 mm). It is contemplated that outer portion 96 and inner portion 92 may be substantially straight from tangent point 104 to curved portion 94.
As shown in FIG. 7, strap 46 may attach to cradle 26 via pivoting members 106. Each pivoting member 106 may be a rigid member with a curved interior surface 114. It is contemplated that interior surface 114 may conform to an outer surface of exhaust treatment device 22. A first pivoting member 118 may be located on a lower surface of exhaust treatment device 22 and a second pivoting member 120 may be located on an upper surface of exhaust treatment device 22. It is contemplated that a length of pivoting members 106 may vary. For example, first pivoting member 118 may be longer than second pivoting member 120.
Referring to FIG. 8, each pivoting member 106 may include at least one pivot point. Specifically, each pivoting member 106 may include two pivot points. A first pivot point 110 may be located at a junction between strap 46 and pivoting member 106. (See also FIG. 7.) A second pivot point 112 may be located at a junction between pivoting member 106 and cradle 26, or more specifically between pivoting member 106 and first bracket 28 and/or second bracket 30. Each pivoting member 106 may pivot at pivot point about pins 80. Pins 80 may be located interior to loops 64 and 74. Pins 80 may secure pivoting members 106 to cradle 26, thus securing strap 46 to cradle 26. Pivoting members 106 may be composed of, for example, metal, composite, polymer or any other appropriate material known in the art.

INDUSTRIAL APPLICABILITY

The disclosed strap may be applicable to any emissions control system. The loops of the disclosed strap may have a flat outer portion and a flat inner portion, and thus may be free from extraneous folds and bends that create stress concentrations. Additionally, the outer portion may diverge from abutting the inner portion at an angle of no more than 10 degrees. This ensures that the inner portion and the outer portion are near parallel to one another, which reduces stresses in the loop.
The disclosed strap may also include a point of securement for the loop that is distanced from an end of the loop. This may increase a length of the loop and provide enhanced stability and reduced stress concentrations in the loop. Decreasing stress concentrations may increase the usable life of the strap. Additionally, the disclosed pivoting members may reduce fatigue failures due to rocking of the exhaust treatment device in the disclosed cradle. The pivoting members may be especially effective in high vibration applications.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed straps and related structure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed straps. For example, in an alternative embodiment, it is contemplated that the disclosed strap may be a unitary strap. In this embodiment, the strap may be composed of a single piece of flexible material with a coupler located on each end (e.g., a loop on one end and a ratchet on the other end). Each coupler may couple to the cradle to secure an exhaust treatment device. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims.

Claims

1. A strap for securing an exhaust treatment device, comprising:

a coupler on a first end; and

a loop on a second end, the loop including an inner portion, a curved portion, and an outer portion of the strap,

wherein the outer portion of the strap is secured to the inner portion of the strap at a point of securement to form the loop, wherein the outer portion forms an angle with respect to the inner portion that is no greater than about 10 degrees as the outer portion diverges from abutting the inner portion.

2. The strap of claim wherein the angle is more preferably between about 8-10 degrees.

3. The strap of claim 1, wherein the strap includes a first strap member and a second strap member, wherein the first strap member and the second strap member are coupled together via a pair of threaded couplers.

4. The strap of claim 1, wherein the outer portion of the strap is secured to the inner portion of the strap via welding or mechanical fastening.

5. The strap of claim 1, wherein the loop is a first loop and the coupler is a second loop, the first loop attaching to a cradle on a first side of the cradle, the second loop attaching to a second side of the cradle such that the strap passes around at least portion of an outer periphery of the exhaust treatment device and secures the exhaust treatment device to the cradle.

6. The strap of claim 5, wherein a first loop length is no less than one third of an effective length of the strap, wherein the effective length is defined as a distance from the curved portion of the first loop to an end of the second loop, the loop length being defined as a distance from the curved portion of the first loop to the point of securement of the outer portion and the inner portion of the first loop.

7. A strap for securing an exhaust treatment device, comprising:

a first strap member including a coupler on a first end and a loop on a second end;

a second strap member including:

a coupler on a first end configured to couple with the coupler of the first strap member, and

a loop on a second end, the loop including a flexible band of material being looped and secured to itself at a point of securement, wherein a loop length is no less than one third of an effective length of the strap, wherein the effective length is defined as a distance from an end of the loop of the first strap member to an end of the loop of the second strap member when the coupler of the first strap member is coupled to the coupler of the second strap member, the loop length being defined as a distance from an end of the loop of the second strap member to the point of securement.

8. The strap of claim 7, wherein the loop length is one third of the effective length.

9. The strap of claim 7, wherein the loop on the second end of the second strap member includes an inner portion, a curved portion, and an outer portion of the band of material, wherein the outer portion of the band is secured to the inner portion of the band at the point of securement, the outer portion forming an angle with respect to the inner portion that is no greater than about 10 degrees as the outer portion diverges from abutting the inner portion.

10. The strap of claim 9, wherein the angle is more preferably between about 8-10 degrees.

11. The strap of claim 7, wherein the coupler of the first strap member and the coupler of the second strap member include threaded couplers.

12. The strap of claim 7, wherein the loop on the second end of the first strap member also includes a flexible band of material being looped and secured to itself at a point of securement, the flexible band of material for both the first strap member and the second strap member attaching to itself via welding or mechanical fastening.

13. The strap of claim 12, wherein the loop of the first strap member and the loop of the second strap member are each attached to a cradle to secure an exhaust treatment device to the cradle, and wherein the first strap member and second strap member pass around at least portion of an outer periphery of the exhaust treatment device.

14. The strap of claim 13, wherein the exhaust treatment device is selected from a group consisting of a diesel oxidation catalyst, a particulate filter, a selective catalytic reduction device, a lean NOx trap, a regeneration device, or a reductant mixing device.

15. The strap of claim 7, wherein the second strap member includes a single piece of flexible material that is looped and secured to itself a first time to create the loop on the second end and looped and secured to itself a second time to create a part of the coupler on the first end.

16. An exhaust treatment system comprising:

a cradle;

an exhaust treatment device situated in the cradle;

a strap passing around at least a portion of the exhaust treatment device to secure the exhaust treatment device to the cradle, the strap including:

a first loop on a first end of the strap connected to the cradle; and

a second loop on a second end of the strap connected to the cradle, the second loop including a flexible band of material being looped and secured to itself at a point of securement, wherein a loop length is no less than one third of an effective length of the strap, wherein the effective length is defined as a distance from an end of the first loop to an end of the second loop, the loop length being defined as a distance from the end of the second loop to the point of securement.

17. The exhaust treatment system of claim 16, wherein the exhaust treatment device is selected from a group consisting of a diesel oxidation catalyst, a particulate filter, a selective catalytic reduction device, a lean NOx trap, a regeneration device, or a reductant mixing device.

18. The exhaust treatment system of claim 16, wherein the strap includes a first strap member and a second strap member.

19. The exhaust treatment system of claim 18, wherein the distance from the point of securement related to the first loop to the point where the first strap member contacts an outer surface of the exhaust treatment device is no less than about two inches.

20. The exhaust treatment system of claim 18, wherein each of the first strap member and the second strap member are connected to a pivoting member that includes at least one pivot point.