Abstract:
An adjustable restrictor device for controlling flow of induction air into an engine. The restrictor device may comprise a generally flat compact housing which is installed between a carburetor and intake manifold of an engine. The housing may have throughbores to allow air flow, which coincide in location to carburetor bores. The restrictor device may have two individual restrictors enclosed therein, each movable to positions which progressively obstruct and open the throughbores to control flow of inducted air. Each restrictor may be manually controlled in common by a rotatable control shaft. Threading of the knobs may be opposite handed, thereby enabling the restrictors to move similarly in effect as to controlling air flow but in opposite directions.

Description:
REFERENCE TO RELATED APPLICATION 
     This application claims priority of a Provisional Patent Application filed Jun. 30, 2010, application No. 61/360,065, the contents of which are incorporated herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a manually adjustable valve for controlling flow of inducted combustion air into an internal combustion engine. 
     BACKGROUND OF THE INVENTION 
     One form of drag racing which has become popular is known as bracket racing. The term “bracket” refers to a window of time that is required for the vehicle to start and complete a prescribed race course, typically a straight quarter mile course. In bracket racing, drag race vehicles are pitted against other such vehicles of generally similar racing abilities because for any given race, vehicles must have race times or alternatively stated, complete the course, in a time interval that is neither less than nor greater than the magnitude of the selected time interval or bracket. 
     The advantage of this arrangement is that it assures a fairly close race. Otherwise, all other things being equal, the race will be won by that competitor who has devoted more technical resources, and therefore financial resources, to developing a faster race vehicle. Limiting participation of race vehicles to predetermined time brackets both assures a close race, which is of greater interest to spectators, and imposes a limit on otherwise unlimited spending in an effort to become ever faster. 
     The concept of bracket racing essentially rewards consistency over sheer speed. That is, it becomes desirable to remain within a particular bracket to avoid disqualification in races. At the same time, it is desired to finish the race in an elapsed time period which is the minimum of the predetermined time bracket. 
     Vehicles for bracket racing have become so developed in their ability to finish races within a particular time bracket that influences such as ambient temperature, humidity, wind speed and direction, and other factors may cause a race vehicle to cover the course too fast and thus be disqualified, or to become slower to the point of being uncompetitive in the selected time bracket. A way of establishing fine control over maximum horsepower would address these problems. 
     In NASCAR racing, so-called restrictor plates are used to achieve a certain level of parity among race vehicles. While restrictor plates serve their intended purpose in stock car racing situations, they would not be truly useful in bracket constrained drag racing since they are fixed in their levels of control and cannot assure that the race vehicle on which one is placed will actually be limited to any particular elapsed time bracket. 
     There exists a need in bracket racing to be able to modify engines of race vehicles under closely controlled constraints to enable small adjustments of engine power to suit prevailing conditions in order for a particular race vehicle to qualify for and be competitive within a particular time bracket. 
     SUMMARY OF THE INVENTION 
     The present invention provides a compact device which is generally similar to a restrictor plate, but which provides ability to make fine adjustments to the degree of restriction which is achieved. 
     The novel restrictor device incorporates at least one adjustable restrictor which is movable to achieve infinite increments of adjustment, so that an engine may be tuned such that drag race results are confined to a particular predetermined elapsed time bracket. The adjustable restrictor moves laterally once placed on a typical engine, so that it moves perpendicularly to the flow of inducted air. The adjustable restrictor is compactly enclosed in a surrounding housing. One or more adjustment knobs may project laterally from the housing. 
     The number of restrictors may be more than one. Illustratively, in a currently preferred embodiment, two restrictors are provided, each restricting or controlling two carburetor bores of a four barrel carburetor for example. In this embodiment, each restrictor is provided with a common control shaft. The shaft may be passed through threaded holes formed in the housing, with the threading being of opposite hand so that the two restrictors are moved in opposite directions by the one control shaft. 
     It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is an exploded diagrammatic end view of a typical V8 or V6 engine, showing the mounting location of an adjustable restrictor according to an aspect of the invention. 
         FIG. 2  is an exploded perspective view of an adjustable restrictor according to at least one aspect of the invention. 
         FIG. 3  is a top plan view of the components of  FIG. 2 , with the uppermost component removed to reveal internal positional details, with gate valve elements shown in one position of a range of adjustment positions. 
         FIG. 4  is a top plan view similar to  FIG. 3 , but showing the gate valve elements adjusted to another position of the range of adjustment positions. 
         FIG. 5  is an exploded perspective detail view of one gate valve element and associated components. 
     
    
    
     DETAILED DESCRIPTION 
     Referring first to  FIG. 1 , according to at least one aspect of the invention, there is shown an adjustable restrictor device  100  as it would be installed onto the intake manifold  10  of an internal combustion engine  12 . After assembly, the adjustable restrictor device  100  will be sandwiched between the intake manifold  10  and a carburetion device such as a carburetor  14  or fuel injection throttle body (not shown). The adjustable restrictor device  100  may be held in place by fasteners  16  which secure the carburetion device to the intake manifold  10 . Although shown as bolts, the fasteners  16  may comprise studs (not shown) anchored in the intake manifold  10  and cooperating nuts (not shown). After installation, the adjustable restrictor device  100  will be fairly inconspicuous and will add to only a limited degree to the overall height of the engine assembly. After installation, and as will be further detailed hereinafter, the adjustable restrictor device  100  may be utilized to control flow of inducted combustion air into the internal combustion engine  12 . 
       FIG. 2  shows the principal components of the adjustable restrictor device  100 , which principal components include a base  102 , a cover  104 , and two gate valves or restrictors  106 ,  108 . The base  102  and cover  104  collectively form a housing comprising a face surface  110  which is disposed perpendicularly to the direction of combustion air flowing through the housing into the engine, such as the internal combustion engine  12 . 
     The base  102  and the cover  104  provide two complementing sections which when assembled result in an internal chamber being formed therebetween. The restrictors  106 ,  108  are contained within the internal chamber. 
     The base  102  and cover  104  respectively bear a plurality of openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126 ,  128  for passing air into the engine. The openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126 ,  128  are formed in surfaces parallel to the face surface  110 , and further may be disposed in vertical registry with corresponding throttle bores (not shown) formed in the carburetion device. Illustratively, the carburetion device may be a four barreled carburetor (not shown) having four throttle bores. The openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126 ,  128  may each have an axis such as the axis  131  which coincides with the openings of the carburetor. It may be stressed at this point that the face surface  110  is important only in that it provides semantic basis for a hypothetical plane which passes through the adjustable restrictor  100  and is perpendicular to the flow of air through the various openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126 ,  128 . 
     After assembly, the base  102  and cover  104  seal the induction passage established by the carburetion device and intake manifold from ambient air, so that characteristics of air and fuel flow are not altered during passage from the carburetion device to the intake manifold. The role of the adjustable restrictor device  100  is to selectively increase and decrease maximum air and fuel flow so as to selectively limit maximum power which may be developed by the engine. 
     Increasing and decreasing air and fuel flow, which will be referred to subsequently as throttling, is accomplished by adjusting position of the restrictors  106 ,  108  so as to selectively partially obstruct the effective surface area of the openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126 ,  128 . Although the restrictors may be moved in other directions if desired, results are obtained efficiently by moving the restrictors  106 ,  108  perpendicularly to the direction of combustion air flowing through the adjustable restrictor device  100 , or alternatively stated, the restrictors  106 ,  108 , which are supported by the housing and fully enclosed therein., are each disposed to move in a direction generally parallel to the face surface  110  of the housing. 
     The restrictor  106  may have gently rounded shallow troughs  172 ,  174  formed therein. The restrictor  108  may have comparable troughs  175 ,  177 . 
     The restrictors  106 ,  108  may be disposed to move in mutual opposition to one another in the directions indicated by the arrows  128 ,  130  in the following way. Each restrictor  106  or  108  may be controlled by a control shaft which may comprise a first control shaft section  132  and a second control shaft section  134 . The control shaft may have external threading sections  136 ,  138  respectively, which external threading sections  136 ,  138  cooperate with corresponding threaded holes  140 ,  142  formed in the base  102 . The control shaft sections  132 ,  134  are joined together, for example by welding, adhering, rivets, threaded fasteners, or other means (not shown) after inserting each control shaft section  132  or  134  into place from opposite sides of the housing. After the control shaft section  134  is passed through a hole  175 , and the control shaft section  132  is passed through a corresponding hole (not visible in the view of  FIG. 2 ) from the opposite side of the housing, the tips of the two control shaft sections  132 ,  134  may be welded together using the opening  180  for welding access. Alternatively the control shaft utilized may merely be a single rod with portions of thread of opposite pitch. 
     The resultant single control shaft is rotatably supported on the housing in an orientation such that it may move the restrictors  106 ,  108  in opposite directions (such as indicated by the arrows  128 ,  130 ) parallel to the face surface  110  of the cover  104  when rotated by either end (e.g., the section  132  or the section  134 ). Further rotation exerts a force on the respective restrictor  106  or  108  and moves the restrictor  106  or  108  to a new position. When supported in a threaded hole such as the threaded  140  or  142 , it follows that rotation of the enlarged head  144  or  146  will cause the control shaft to move helically. 
     The effect of moving the restrictors  106 ,  108  to new positions is illustrated in  FIGS. 3 and 4 . In  FIG. 3 , the restrictors  106 ,  108  are shown at the outer limits of travel such that the openings  120 ,  122 ,  124 ,  126  are fully exposed to air flow. It should be appreciated that the control shaft (the welded control shaft sections  132 ,  134 ) remains at a generally constant or unmoved location on the housing, and the restrictors  106 ,  108  move laterally along the control shaft as they traverse the threaded portions  136 ,  138 . 
     As seen in  FIG. 4 , the control shaft may be rotated to adjust the restrictors  106 ,  108  to new positions in which the openings  120 ,  122 ,  124 ,  126  are partially obstructed. As depicted in  FIG. 4 , this movement leaves a gap to the left of the restrictor  106  and a gap to the right of the restrictor  108  through which gaps the control shaft becomes revealed. 
     For convenience of operation, the control shaft projects to the exterior of the housing so as to be accessible for movement from the exterior thereof. The control shaft  134  may be grasped and rotated by hand using either of respective enlarged knurled heads  144 ,  146 . 
     The control shaft also may perform the function of repeatably resetting the restrictors  106 ,  108 . For example, the restrictors  106 ,  108  may be adjusted to the fully obstructed position, and then adjusted by rotating the control shaft by a predetermined definite number of turns. The user may monitor ambient weather conditions such as barometric pressure, humidity, temperature, wind speed and direction, and the like, and may make adjustments to the initial setting established by the predetermined number of turns of the control shaft. The results may be noted, with degree of fine control due to weather conditions being factored in to modify the initial setting in subsequent racing. 
     The restrictors  106 ,  108  may be arranged to move in mutual opposition to one another. That is, as the restrictor  106  is adjusted from the position shown in  FIG. 3  to the position shown in  FIG. 4 , the restrictor  108  moves similarly but in an opposite direction of travel. With the threading sections  136 ,  138  each being of opposite hand to the other, each of the threading sections  136 ,  138  controlling one restrictor  106  or  108 , either enlarged knurled head  144  or  146  may be grasped by one hand and rotated with the fingers. Thus the restrictors  106 ,  108  may be moved in opposite directions despite one direction of rotation of their respective control shaft. Similar adjustments may be made by rotating either of the enlarged knurled heads  144  or  146 . Because the control shaft projects from the housing at opposite sides of the housing, each of the enlarged knurled heads  144  or  146  is located on one side of the adjustable restrictor assembly  100 . This affords the convenience of being able to adjust the restrictors  106 ,  108  from different locations. Although the present application discloses an embodiment utilizing two knurled heads  144 ,  146 , it should be appreciated that the present invention may be operated by a single knurled head. 
     It will be apparent from examining  FIG. 2  that bolt holes  148 ,  150 ,  152 ,  154  formed in the cover  104  are generally coaxial with bolt holes  156 ,  158 ,  160 ,  162  formed in the base  102 . These bolt holes  148 ,  150 ,  152 ,  154 ,  156 ,  158 ,  160 ,  162  may be located and dimensioned so as to cooperate with the bolt pattern established by the fasteners  16  (see  FIG. 1 ), and may for example, duplicate the function of similar fasteners originally provided by the manufacturer of the engine  12  to mount the carburetion device to the intake manifold  10 . 
       FIG. 5  shows a feature for immobilizing a restrictor such as the restrictor  106  in a selected position of adjustment. A small spring  164  may be arranged to impose force on a block  166 . The small spring  164  may seat at one end against a threaded set screw  168  which is inserted into the restrictor  106  to contain the spring  164  and at the other end, against an end surface of the block  166 . The block  166  is forced by the spring to make contact with the adjusting screw threads  136  (not shown in  FIG. 5 ) imposing forces which act to pin the threaded shaft  132  (also not shown in  FIG. 5 ) in place so that adjustment of the restrictor is preserved. 
     The present invention may be modified in many ways to similar effect. For example, whereas the cover  104  and the base  102  are shown as having four openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126  respectively, the number and configuration of these openings  112 ,  114 ,  116 ,  118 ,  120 ,  122 ,  124 ,  126  may be varied to suit conditions for each engine or to suit manufacturing convenience. For example, pairs of openings such as the openings  112 ,  114  may be made to communicate or alternatively stated, may be siamesed. 
     The number of restrictors such as the restrictors  106 ,  108  may be increased or decreased. For example, each opening  112 ,  114 ,  116 ,  118  may be provided with an individual restrictor (not shown) if desired. Restrictors may be yoked together and adjusted by only one control shaft (this option is not shown). 
     The housing may be formed as a pocket open at only one end, with a suitable restrictor or restrictors inserted through the open end if desired (this option is not shown). 
     The control shaft arrangement may be modified to include traveling nuts (not shown) which propel the respective restrictors such as the restrictors  106 ,  108  by interference. A singular control shaft may be replaced by plural control shafts (not shown, each control shaft controlling a different restrictor. For example, the restrictors  106 ,  108  each have an opening such as the opening  170  for receiving the tip of a control shaft such as the control shaft  134 . Such an opening may be modified to enclose and entrap an enlarged terminal so that the associated restrictor is subjected to pulling forces when the control shaft is rotated in one direction and subjected to pushing forces when the control shaft is rotated in the other direction. 
     Components of the adjustable restrictor device  100  shown coupled to the base  102  may be coupled to the cover  104  where feasible. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible.