Patent Application
20130175115
1. Field of the Invention
This invention relates to the baffling device placed in the exhaust stream of an internal combustion engine. Specifically, it relates to a device that allows the operator to choose between varying noise control and performance levels.
2. Description of the Prior Art
Internal combustion engines that have been tuned for high performance such as those found in race cars or motorcycles, often include an exhaust system that lacks any substantial noise control device. This is necessarily the case, since noise control devices often impose restrictions to flow which would hinder the performance of these engines.
Often the described vehicles are operated in residential areas where noise level mandates dictate a maximum lawful level of noise that may be produced by on-road vehicles.
There are some devices currently available that offer a compromise between noise control, and performance. One of these devices is often referred to as an exhaust cutout. This device is placed in-line with a conventional exhaust designed for noise control, and when activated a shorter secondary path that is designed for performance opens creating a less restrictive path through which the exhaust will flow. This type of device would be difficult to fit in tight applications on cars, and nearly impossible to practically install on a motorcycle.
Another method that has been devised is demonstrated in U.S. Pat. No. 4,541,506. This patent describes a product which would require extensive exhaust modification in order to adapt this product. Many times the required modification may not be desirable or even possible in the given application.
The main objective of this invention is to offer an improved device that is easily installed within the existing exhaust system with little or no modification, and permits the operator to select the desired balance of noise control and performance without tools.
The presented invention is intended to offer an improved exhaust baffling device that offers two or more modes of varying noise and performance levels. The device has a rotating baffle assembly that in one extreme position restricts exhaust flow to control noise level of the exhaust, and in the other extreme position allows for as little restriction as possible to maximize engine performance. This device is easily installed without significant exhaust system modification and adjustable to any of the two or more positions without tools.
The baffle assembly 12 consists of two baffle plates 13 connected by two lifting tabs 14. The lifting tabs 14 provide for a means of lifting axially, and rotating about the pivot shaft 15. Each baffle plate 13 has a varying quantity, size, and pattern of passages 17 through which exhaust gas may pass when place transverse to exhaust flow. Each baffle plate 13 has a locking tab 18 that extends towards the tubular body 11 where there are corresponding slots that receive said tabs causing the baffle assembly 12 to rotationally lock in a position when acted upon by the spring 19.
The tubular body 11 may include one or more holes 16 on its perimeter that may be used for mounting the device 10 into the existing exhaust system 24.
To provide noise level control the baffle assembly 12 is acted upon parallel to the axis of the pivot shaft 15 to compress the spring 19 until locking tabs 18 have been completely removed from locking boss 23. The baffle assembly 12 can then be rotated about pivot shaft 15 until locking tabs 18 are in alignment with locking boss 20. When the baffle assembly 12 is released the spring 19 will act on lifting tab 14 forcing the baffle assembly 12 to engage into locking boss 20. Doing so positions the baffle assembly 12 transverse to exhaust flow significantly reducing the open area in the exhaust passage. When the open area of the exhaust is reduced in this manner back pressure in the exhaust upstream from the invention increases thus providing the noise control desired.
When performance mode is desired and noise control is no longer needed, the baffle assembly 12 is acted upon parallel to the axis of the pivot shaft 15 to compress the spring 19 until the locking tabs 18 have been completely removed from the locking boss 20. The baffle assembly 12 can then be rotated about pivot shaft 15 until the locking tabs 18 are in alignment with locking boss 23. When released the spring 19 will act on lifting tab 14 forcing the baffle assembly 12 to engage locking boss 23. Doing so positions the baffle assembly 12 generally parallel to exhaust flow, maximizing open area through which the exhaust can flow. When maximum open area is provided, performance of the vehicle will be maximized.
In addition to performance mode, and noise control mode this invention offers one or more hybrid modes. These modes offer a balance of noise control and performance. If a hybrid mode is desired the baffle assembly 12 is acted upon parallel to the axis of the pivot shaft 15 to compress the spring 19 until the locking tabs 18 have been completely removed from the locking boss in which it is currently positioned. The baffle assembly 12 can then be rotated about the pivot shaft 15 until locking tabs 18 are in alignment with either locking boss 21 or 22 depending on the hybrid mode desired. When released, the spring 19 will act on lifting tab 14 forcing the baffle assembly 12 to engage the selected locking boss, 21 or 22.
