Patent Application
20200217443
This invention relates generally to insulated tubes and insulated tube construction methods.
In the automotive industry, exhaust tubes are insulated to retain heat and thereby improve exhaust efficiencies and emissions, as well as protect nearby vehicle components and personnel. Many types of insulation and manufacturing methods are known, but many are difficult and costly to manufacture.
Further, tube insulation tends to be less efficient wherever tubes bend, or have connectors or other protuberances that interfere with the insulation, causing the insulation the be less effective and more difficult to apply at such locations.
Manufacturing exhaust tubes can be time consuming and expensive because the process typically requires hand assembly and multiple steps. In one example, an exhaust tube is wrapped with a sheet of insulating material that matches the length of the tube. The wrapped sheet results in a longitudinal seam along the tube that is taped or wrapped to hold the edges of the sheet together and form a seam while an outer protective cover is applied. This approach is successful in insulating the tube, but is time-consuming and difficult to assemble. Errors or slippage can result in gaps along the seam of the insulation.
Another example disclosed in U.S. Pat. No. 9,976,687 B2 uses a braided sleeve over a tube, but then uses a slurry of resin and fibers applied to the sleeve that must then be dried or baked to solidify and retain its shape. This method is time-consuming and difficult to execute.
Other examples of such exhaust tube insulations and methods of manufacturing are disclosed in: U.S. Patent Application Publication No. 2018/0238221 published Aug. 23, 2018; U.S. Pat. No. 10,329,991 issued Jun. 25, 2019; International Publication No. WO 2017/181197 published Oct. 19, 2017; U.S. Patent Application Publication No. 2016/0311152 published Oct. 27, 2016; U.S. Pat. No. 9,388,515 issued Jul. 12, 2016; International Publication No. WO 97/32067 published Sep. 4, 1997; U.S. Patent Application Publication No. 2010/0154917 published Jun. 24, 2010; U.S. Pat. No. 4,287,245 issued Sep. 1, 1981; U.S. Pat. 6,000,438 issued Dec. 14, 1999; U.S. Pat. No. 6,403,180 issued Jun. 11, 2002; U.S. Patent Application Publication No. 2007/0102055 published May 10, 2007; German Patent Publication 10 2010 028 433 published Nov. 3, 2011; U.S. Pat. No. 8,950,168 issued Feb. 10, 2015; and U.S. Patent Application Publication No. 2007/0049148 published Mar. 1, 2007.
Thus, there is a need for improved tube insulation and manufacturing methods that provide uniform insulation, including at bends and protuberances of the tubes, which can be accomplished efficiently during the manufacturing process.
The present invention provides a uniform tube insulation, and efficient and inexpensive method of manufacturing tubular insulation. In accordance with the present invention, a method for manufacturing an insulated vehicle exhaust tube, includes the steps of: sliding an insulating sleeve over an exhaust tube section; adjusting the insulating sleeve to a substantially uniform material thickness over the pipe section; restraining the ends of the insulating sleeve relative to the exhaust tube section; allowing a central portion of the insulating sleeve to remain unrestrained relative to the tube section; and enclosing the insulating sleeve with a metal protective cover. Preferably, the insulating sleeve is a braided material that slides over the tube from one end. It is also possible to have more than one insulating sleeve with the insulating sleeves positioned end-to-end or in layers.
The metal protective cover can be texturized and be a thin foil to resist denting, creasing, and other deformities. As stated above, more than one insulating sleeve can be used to improve insulation properties and temperature retention in the tube, and the layered insulating sleeves can be adjusted to provide relatively uniform and seamless insulation for the exhaust tube.
In the method, the step of restraining the ends of the insulating sleeve can include the step of: wrapping end portions of the insulating sleeve with a restraining material such as a plastic or fabric wrap.
Further, the step of restraining the ends of the insulating sleeve can include the steps of: wrapping end portions of the insulating sleeve with a restraining material; and trimming excess end portions of the insulating sleeve that extend outwardly beyond the restraining material. Another option for the step of restraining the ends of the insulating sleeve includes the step of: wrapping end portions of the insulating sleeve with tape, or the step of: wrapping end portions of the insulating sleeve with a sheet material free of adhesives.
Other features and advantages of the present invention are described below in the Detailed Description of the Invention.
The insulated tube 20 can be used in any type of vehicle on which insulated exhaust tubes are desirable, including those applications where insulation was once considered too expensive because the present invention saves considerable expense in materials and manufacturing.
Also seen in
An extra portion 48 of the insulating sleeve 36 may result from cutting, installing, and positioning the insulating sleeve 36. The restraining material 44 can hold some of the extra portion 48 in place, while an unrestrained portion extends outwardly. The unrestrained extra portion 48 is illustrated as a frayed portion, but it can be any extra material that is not needed on the portion of the insulated tube 20, and is rolled over or tucked in, or is preferably trimmed off using a rotary cutter, scissors, knife, or other device. The ends of the insulating sleeve 36 can also be prepared in any suitable manner before installation to prevent or reduce fraying.
In the illustrated embodiment, a central portion 52 of the insulating sleeve 36 is not wrapped and is permitted to be unrestrained, at least temporarily, to allow for readjustment of the braided sleeve 36, for example, before further manufacturing steps are performed. Restraining only a portion of the insulating sleeve 36, such as the end portions 46, anchors the insulating sleeve 36 while the remaining portions, such as the central portion 52, are adjusted as necessary to accommodate the shape of the exhaust tube 22, and simplifies the production of the insulated tube 20.
Once the insulating sleeve 36 is adjusted into a desired position of a substantially uniform thickness, the central portion 52 can be wrapped with a restraining wrap 54, as seen in
Depicted in
The collars 58 extend outwardly from the exhaust tube 22 a distance that preferably matches the thickness of the insulating sleeve 36, but other collar dimensions are possible, particularly to accommodate the thickness of any restraining material 44 or additional insulation layers (see below) being used. Also preferably, the collars 58 are joined to the exhaust tube 22 to provide reinforcement for the exhaust tube 22.
After the insulating sleeve 36 is properly positioned, and any restraining material 44 is applied, a protective cover 60 is added around the outside. The protective cover 60 is preferably metal and is attached to the collars 58 when they are used, but the protective cover 60 can be tapered or stepped down and attached directly to the exhaust tube 22 at the ends. The attachment can be made with welds, adhesives, and mechanical fasteners, as examples.
The metal protective cover 60 can be a tubular sleeve or a sheet wrapped around and secured to itself at a crimp 62, as seen in
Also, preferably the metal protective cover 60 is textured to provide increased rigidity and resistance to creases and wrinkles, for example, as well as any desired ornamental features. Any suitable texture can be employed. Optionally, the outer protective cover can include: insulated wire mesh sleeve; insulated wire mesh wrap; wrapped mesh screen; stamped foil; wrapped foil; duct tape; metal/foil tape; and wire braid, as well as those depicted in
The above detailed description is provided for understanding the depicted embodiments of the present invention, and no unnecessary limitations therefrom should be read into the following claims.
This application claims the benefit of U.S. Provisional Application No. 62/789,579, filed Jan. 8, 2019, the disclosures of which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62789579 | Jan 2019 | US |
