Relatively narrow tubular members are inherently difficult to clean. Process fluids may contain impurities that are be deposited on the interior surface of a tubular member. Smaller diameter piping, drains, conduit and tubing may also have turns around which rigid rods and brushes may not be able to reach to scrub loose accumulated deposits. Heat, humidity and pressure may affect the rate and thickness of accumulated deposits.
The barrels of firearms are one form of tubular members that are difficult to clean. Carbon and other residue from gunpowder and from firearm discharge reactions accumulate in firearm barrels, with deleterious effects on cleanliness, performance, and longevity of the firearm. Such residues require partial disassembly of a weapon to access and clean the barrel and associated firing chamber. A number of specialized swabbing, brushing and scraping tools have been introduced to clean firearm components, but have had substantial shortcomings.
U.S. Pat. No. 4,716,673 discloses a gun barrel cleaner comprising an elongated flexible shaft having a universal coupling secured to each opposite end and several different cleaning tips selectively threadably and detachably engageable with either universal coupling. One cleaning tip, a gun barrel bore obstruction remover, comprises a cylindrical body portion having a concave face at one end and securing means at the other end for attaching the tip to the shaft. A compact cylindrical container for storing and conveniently transporting the gun barrel cleaner is provided. In addition, an improved method of attaching a cleaning patch to a gun barrel cleaning tip having a patch receiving slot is provided.
A disadvantage of this invention is that the cleaning patch is not integral with a brush or a scrubbing element of the tool. Therefore, cleaning operations will generally require more than a successive passes of the gun barrel cleaner through the barrel. For example, a first pass of the tool may include a slotted tip with a swab wetted with an appropriate solvent; a second pass may include a pulling an appropriately sized bore brush; a third pass may include a clean swab pulled through the barrel to absorb the dislodged residue; and a fourth pass may include pulling another swab wetted with a preserving lubricant
U.S. Pat. Nos. 5,871,589 and 5,972,125 disclose a cleaning tool for cleaning the inside of gun barrels. The device consists of a metal brush which is enclosed within a tubular sheath of material, typically a woven fabric. The bristles of the brush extend through the wall of the woven sheath of fabric. The tubular sheath is pulled through a gun barrel and the bristles of the brush clean the inside of the gun barrel. Also enclosed within the tubular sheath are one or more foam inserts, or one or more cleaning regions formed by folding the cord within itself, either of which creates a bulge in the tubular sheath and cleans debris from the gun barrel, spreads gun cleaning solvent in the gun barrel, absorbs solvent and combustion and bullet residues, and spreads a layer of gun oil in the gun barrel.
A shortcoming of the device disclosed in both patents is that an attached flexible cord for pulling the sheath through the barrel does not extend throughout the length of the sheath. Because the sheath is longitudinally stretchable, the device can jam in a firearm barrel and become difficult to remove. Further, the preferred material of the sheath is a synthetic polymer that is not as absorbent as a natural fiber such as cotton, resulting in less effective presentation of cleaning solvent and/or lubricant against the surface of the barrel, which effect is compounded by a reduction in effective diameter of the sheath under tension. Once jammed, excessive tensile force on the flexible lead cord may result in a failure of the cord, the synthetic sheath or the sewn connection therebetween. As the flexible cord lacks a semi-rigid core, it is frequently difficult to feed or thread the flexible cord through the tubular member, particularly when the bore of the tube or gun barrel is partially obstructed by mud, debris, an excessive accumulation of carbon residue, or a combination thereof. Consequentially, a further disadvantage is that the flexible shaft does not comprise an integral gun barrel obstruction remover. Further, no fitting is provided at the leading or trailing end of the sheath for attachment of auxiliary cleaning tools as may be desirable.