Abstract:
A Vacuum Relief Assembly for I.C. Engine Intakes is disclosed. Also disclosed is a device that permits outside air into the intake tract of an internal combustion engine in the event of an excessively high vacuum condition within the intake tract. Furthermore, the device is constructed from durable materials and resists the excessive temperatures found in the engine compartment of a vehicle. Still further, the device is made from two half-cylindrical sections that mate to one another around the intake tract to form a cylindrical attachment. The method of installation enables the device to be installable onto the intake tract in situ, and without the need to cut out a section of the tract.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates generally to Engine Intake Accessories and, more specifically, to a Vacuum Relief Assembly for I.C. Engine Intakes.  
         [0003]     2. Description of Related Art  
         [0004]     After-market accessories for improving the performance of stock internal combustion engines has become a enormous industry. One particular focus of the performance accessory industry is that of intake systems. A performance-enhancing modification is to relocate the stock air intake duct from its normal location deep within the engine compartment. It has been determined that when the vehicle is operated in warm climates, the air within the engine compartment becomes very hot; this means that the stock engine is taking hot air into its intake system. As the intake air becomes hotter, the engine performance declines. One solution to this is to add a “cold air intake” assembly to the engine assembly. The cold air intake essentially relocates the intake inlet to a position low-down in the engine compartment, typically behind the front bumper-putting the air intake down and forward of its stock location provides the engine with cooler intake air (at least cooler than that available in the engine compartment).  
         [0005]     One problem with relocating the air intake so low is that it can become clogged by water or debris thrown up from the road surface. As the intake inlet becomes clogged, the engine is starved for air, and begins to lose power and efficiency.  FIG. 1  is an introduction to the conventional I.C. intake system.  
         [0006]      FIG. 1  is a schematic diagram of pertinent portions of a conventional internal combustion engine assembly  30 . The typical internal combustion engine  32  has an intake plenum  34  associated with it for delivering intake air to the engine  32 . The plenum  34  has a throttle body  38  that adjusts the intake airflow into the plenum  34 . Air is supplied to the throttle body  38  via the intake tube  40 , which obtains air from the environment through an intake air filter  42 . The filter  42  shown here is intended to simulate a cold-air intake previously discussed. Combustion gases exit the engine  32  via an exhaust manifold  36 .  
         [0007]     As discussed above, if the intake air filter  38  is clogged (such as by dowsing or submerging in water), insufficient air will be provided through the intake tube  40 , throttle body  38  and plenum  34  for supporting combustion in the engine  32 ; poor engine performance will be the result.  FIG. 2  depicts a prior art attempt at solving this problem.  
         [0008]      FIG. 2  is an exploded perspective view of a prior art pressure relief valve for internal combustion engines  10 . Specifically, the device is the “Intake Tract Negative Pressure Relief Valve for I.C. Engine” of Concialdi, U.S. Pat. No. 6,394,128. The Concialdi valve  10  consists of a pair of ring-shaped tubular elements  11 , which are bonded to one another when the device  10  is assembled. Within the chamber created by the bonded tubular elements  11  is a foam spring element  18 , having a resilient member  17  stretched over it. The resilient member  17  has several diaphragms  19  formed in it that are cooperatively designed to each cover an aperture  14  formed in the tubular elements  11 . There is further a filter element  20  placed over the outer surface of the assembled tubular elements  11 .  
         [0009]     The Concialdi device is designed to be installed along the air intake tube (see  FIG. 1 ) to relieve excess vacuum conditions within the air intake tube. In normal flow and pressure conditions, the diaphragms  19  seal the apertures  14 , thereby allowing air to enter the system via the intake air filter (see  FIG. 1 ). When the internal pressure within the intake tube drops too low, the diaphragms  19  will be pushed inwardly away from the apertures  14 ; this will permit air to flow in through the filter element  20  and the apertures  14 , thereby providing additional combustion air to the I.C. engine. One problem with the Concialdi device is related to its installation;  FIGS. 3A and 3B  discuss this issue.  
         [0010]      FIGS. 3A and 3B  are schematic diagrams of the device  10  of  FIG. 2  being installed in the assembly  30  of  FIG. 1 . In order to install the Concialdi device in an existing I.C. intake system (as is always the case), the intake tube  40  either must be replaced or modified by cutting to create a gap  41  in the tube  40  that is adequately sized to fit the valve  10  into it. Cutting this gap  41  into the tube  40  can be very challenging, and most times will require that the entire intake tube  40  be removed from the engine compartment.  
         [0011]     A further defect in the Concialdi device is related to its long-term durability and reliability. Because the spring element  18  is made from foam material (“ foam rubber”), it is expected to decay and deteriorate over time, due to the constant flow of air past it. As the spring element  18  deteriorates, it will provide less and less biasing force against the diaphragms  19 , which ultimately results in the seals between the diaphragms and the apertures  14  to fail (allowing air to bypass the normal intake air filter).  
         [0012]     What is needed, then, is a device that prevents an under-pressure condition in the intake tube of an internal combustion engine. Furthermore, this device must be easily installed in existing intake air tracts and must demonstrate superior durability and reliability.  
       SUMMARY OF THE INVENTION  
       [0013]     In light of the aforementioned problems associated with the prior devices and methods, it is an object of the present invention to provide a Vacuum Relief Assembly for I.C. Engine Intakes. The device should permit outside air into the intake tract of an internal combustion engine in the event of an excessively high vacuum condition within the intake tract. Furthermore, the device should be constructed from durable materials to resist the excessive temperatures found in the engine compartment of a vehicle. Still further, the device should be made from two half-cylindrical sections that mate to one another around the intake tract to form a cylindrical attachment. The method of installation should enable the device to be installable onto the intake tract in situ, and without the need to cut out a section of the tract.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which:  
         [0015]      FIG. 1  is a schematic diagram of pertinent portions of a conventional internal combustion engine assembly;  
         [0016]      FIG. 2  is an exploded perspective view of a prior art pressure relief valve for internal combustion engines;  
         [0017]      FIGS. 3A and 3B  are schematic diagrams of the device of  FIG. 2  being installed in the assembly of  FIG. 1 ;  
         [0018]      FIG. 4  is a perspective view of a preferred embodiment of the vacuum relief assembly of the present invention;  
         [0019]      FIG. 5  is a perspective view of the first sleeve half of the assembly of  FIG. 4 ;  
         [0020]      FIG. 6  is a perspective view of the first sleeve half of  FIG. 5  depicting the operation of the flap segments of the present invention;  
         [0021]      FIG. 7  is a cutaway end view of the first sleeve half of  FIGS. 5 and 6 ; and  
         [0022]      FIGS. 8A-8B  depict the installation of the vacuum relief valve of  FIGS. 4-7  being installed in the assembly of  FIG. 1 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Vacuum Relief Assembly for I.C. Engine Intakes.  
         [0024]     The present invention can best be understood by initial consideration of  FIG. 4 .  FIG. 4  is a perspective view of a preferred embodiment of the vacuum relief assembly  50  of the present invention. The bulk of the assembly  50  is constructed of a heat resistant, flexible rubberized material that provides long-term durability in the high temperature environment found under the hood of a vehicle&#39;s engine compartment. Other non-rubberized components, where included, are also made from durable long-lasting materials.  
         [0025]     The assembly  50  is made from two mating semi-circular half-sleeves, namely a first sleeve half  52 A and a second sleeve half  52 B. The halves  52  are cooperatively designed to mate to one another to form a full circular collar for attaching to the outer surface of an intake tube (see  FIG. 1 ), such that the intake tube is captured within the inner bore  54  formed by the mated halves  52 , and the tube-engaging surfaces  62  seal against the outer surface of the intake tube. A first ring section  56 A and second ring section  56 B are created by the mated halves  52 , where clamp receiving surfaces  64 A and  64 B are provided for clamping the assembly  50  to the intake tube with suitable clamping devices, such as conventional pipe clamps. The first and second ring sections  56 A and  56 B, respectively, are interconnected with one another by a plurality of struts  60 ; here first strut  60 A, second strut  60 B and third strut  60 C are shown-other configurations are expected to be employed.  
         [0026]     In between each strut  60  is a section of screen  58  that provides structural rigidity to the assembly  50 , while also allowing airflow therethrough to the inner bore  54  (when the soon-to-be-described flaps are open). Unlike the Concialdi device, the assembly  50  is not a solid ring at installation; breaking the assembly in two halves  52  enables the device to be installed on the intake tube without the need to cut a gap. Furthermore, there are no components made from foam rubber or other easily-deteriorating material; the two main materials are durable rubber and stainless steel screen materials. If we now turn to  FIG. 5 , we can investigate the structure of this device in more detail.  
         [0027]      FIG. 5  is a perspective view of the first sleeve half  52 A of the assembly of  FIG. 4 . It should be understood that the first and second sleeve halves  52  are essentially mirror images of one another in virtually all functional respects.  
         [0028]     The inner surface of the inner bore (see  FIG. 4 ) is defined at its ends by the first and second ring sections  56 A and  56 B, respectively. Interconnecting the ring sections is the annular wall  66 . The annular wall is preferably constructed/molded from the same rubberized material that was discussed above. Dispersed across the annular wall  66  are one or more slits  68  penetrating through the material of the wall  66 , such that one or more flap segments  70  are formed from the annular wall  66 . In this embodiment, there are two slits  68  in parallel spaced relation to form a single flap  70 .  
         [0029]     The sleeve half  52 A is defined by a pair of pegs  72 A and  72 B extending outwardly from one of the surfaces that mate with the second sleeve half  52 B. On the opposite end of the sleeve half  52 A, there are a corresponding pair of receivers  74 A and  74 B that are sized to accept pegs  52  extending from the second sleeve half  52 B. The cooperation of the pegs  52  and receivers  74  act to assist in aligning the two sleeve halves  52  when the assembly  50  is being attached to an air intake tube.  
         [0030]     The sleeve half  52 A is also defined by a pair of slots  76 A and  76 B cut through the mating surfaces of the halves. Additionally, there may be a tab  78  extending from the outer surface of the center portion (i.e. between the two ring sections). The tab  78  is provided to engage the outer surface of the second sleeve half  52 B, again, to assist in aligning the two halves when installing the assembly  50  on an air intake tube. We will now turn to  FIG. 6  to examine the functioning of this new device.  
         [0031]      FIG. 6  is a perspective view of the first sleeve half  52 A of  FIG. 5  depicting the operation of the flap segments  70  of the present invention. As discussed above, the annular wall  66  is provided with two slits cut through it to form a flap segment  70 . The flap segment  70  is attached only to the other portions of the annular wall  66 , and not to the struts  60  or screens  78 .  
         [0032]     When the assembly is formed into a ring and attached to the outer surface of the air intake tube, it will react as shown when a pre-determined negative pressure is experienced in the inner bore  54 . In particular, when the pressure on the outer surface of the flap segment  70  becomes sufficient to overcome the force that keeps the flap segment  70  arched outwardly (see  FIG. 5 ), the flap segment  70  will be pushed or pulled towards the center of the inner bore  54 . When the flap segment moves in, openings are created on either side of the flap segment  70 . The openings allow free flow between the inner bore  54  and the outer surface of the annular wall  66 .  
         [0033]     The slots  76  actually connect to one another to form an annular cavity  82  between the screens  78  and struts  60  and the outer surface of the flap segment  70 . The slots  76  from the two attached halves  52  are located to match up when the first mating face  80 A and the second mating face  80 B are mated to the corresponding second and first mating faces, respectively, of the second sleeve half. The annular cavity  82  encircles the annular wall  66  and serves to distribute and equalize the pressure around the circumference of the assembly  50  (i.e. when the two halves  52  are assembled into an completed assembly  50 ).  FIG. 7  provides another aspect of this unique structure.  
         [0034]      FIG. 7  is a cutaway end view of the first sleeve half  52 A of  FIGS. 5 and 6  along section line A-A. The struts  60  will typically protrude radially outward beyond the outer surface of the screen  58 . The screen  58  will typically be embedded in the rubberized material of the struts  60 . Furthermore, the tab  78  is an extension of the strut  60  that is adjacent to the second mating face  80 B (in this half). As shown, the annular cavity  82  is bounded on the inner side by the annular wall  66 , and on the outer side by the screen  58  and struts  60 . There is a radial distance between the inner surface of the tube-engaging surface  62  and the inner surface of the annular wall  66 ; this area forms a chamber around the air intake tube to provide for stabilization of pressures, and further allows the flap segments  70  adequate room to pull inward to create the relief valve openings. Finally turning to  FIGS. 8A-8C , we can discuss the novel installation process for this invention.  
         [0035]      FIGS. 8A-8B  depict the installation of the vacuum relief assembly  50  of  FIGS. 4-7  being installed in the intake tube  40  of the assembly  30  of  FIG. 1 . To install the assembly  50 , one need simply to determine the desired location on the tube  40  for installation of the assembly. Next, one or two apertures  84 A are cut into the walls of the tube  40 . These apertures  84  can be cut in situ, or while the tube  40  remains installed in line with the engine. Next, the two halves  52 A and  52 B are placed over the aperture(s)  84  such that their pegs and receivers interlock to form the circular assembly  30 . Finally, a pair of clamps  86 A and  86 B, such as conventional pipe clamps, are tightened onto the ring sections  56  until the assembly  30  is firmly attached and sealed to the tube  40 .  
         [0036]     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.