Abstract:
An assembly of components for coupling an air filtration device to an engine is disclosed. The assembly includes an adapter component having first and second adapter ends, and a hose having first and second bends and first and second hose ends, where the first hose end is configured for being coupled to an output terminal of the air filtration device and the second hose end is capable of being coupled to the first adapter end of the adapter component. The adapter component further includes a straight tubular section leading up to the second adapter end so that, when the adapter component is assembled with respect to the engine, air is directed from the straight tubular section into the engine.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     This application claims the priority benefit of U.S. Provisional Patent Application No. 60/620,492 filed on Oct. 20, 2004. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH  
       [0002]     Not Applicable.  
       FIELD OF THE INVENTION  
       [0003]     The present invention relates to internal combustion engines that employ carburetors and air filters such as those provided in canister air cleaners for filtering air prior to its being provided to the carburetors.  
       BACKGROUND OF THE INVENTION  
       [0004]     Internal combustion engines typically employ carburetors that mix air with fuel to obtain a fuel-air mixture that is in turn provided to the engine cylinders for combustion. The air provided to the carburetors should be as clean as possible to achieve efficient engine operation, and consequently the air provided to the carburetors is typically first filtered by one or more air filtering devices before entry into the carburetors. In many such engines, the air filtering device(s) are contained within canister air cleaners that are mounted on the engines and coupled to the carburetors by way of various connection devices.  
         [0005]      FIGS. 1 and 3  show exemplary Prior Art configurations of internal combustion engines having carburetors that receive filtered air provided from canister air cleaners by way of various connection devices.  FIG. 1  in particular shows an exemplary horizontal-shaft internal combustion engine  2  (e.g., a Command Twin horizontal-shaft engine manufactured by Kohler Co. of Kohler, Wis.), at the top of which is mounted a conventional canister air cleaner  4 . An output terminal  6  of the canister air cleaner  4  is coupled to a first carburetor air inlet  8  by way of a first set of connection devices  12 .  FIG. 3 , in contrast to  FIG. 1 , shows an exemplary vertical-shaft internal combustion engine  10 , on which is mounted the canister air cleaner  4 . In this case, the output terminal  6  of the canister air cleaner  4  is coupled to a second carburetor air inlet  14  of the engine  10  by way of a second set of connection devices  16 . As shown, the first carburetor air inlet  8  of the horizontal-shaft internal combustion engine  2  is along a top surface  18  of that engine, while the second carburetor air inlet  14  of the vertical-shaft internal combustion engine is along a side surface  20  of that engine.  
         [0006]     Referring additionally to  FIGS. 2 and 4 , the first and second sets of connection devices  12  and  16  are shown in more detail in an exploded fashion, respectively. As shown particularly in  FIG. 2 , the first set of connection devices  12  includes seven components, namely, a cast aluminum elbow  22 , a gasket  24 , a cast aluminum adapter  26 , a molded rubber hose  28 , two screws  30 , and a breather hose  32 . The rubber hose  28  is molded to have a single bend and is for coupling the elbow  22  to the output terminal  6  of the canister air cleaner  4 , while the two screws  30  are used to hold assembled a flange  34  of the elbow  22 , the gasket  24  and the adapter  26  to the first carburetor air inlet  8 . The breather hose fits on an outlet nipple  36  existing along the outer circumference of the gasket  24 . Depending upon the engine, the canister air cleaner  4  can be mounted so that the output terminal  6  is oriented as shown in  FIG. 1  or on the opposite side of the engine.  
         [0007]     The first set of connection devices  12  allow for coupling of the air inlet  8  to the canister air cleaner  4  regardless of its orientation, since the elbow  22  can be rotated 180 degrees with respect to the air inlet  8  (and still be attached to the air inlet by way of the screws  30 ), and the rubber hose  28  can be rotated as necessary to connect the elbow in either position to the canister air cleaner. As for the second set of connection devices  16  shown in  FIG. 4 , these devices include a cast aluminum elbow  38 , a gasket  40 , an adapter  42 , a rubber hose  44  (again molded to have only a single bend), a breather hose  46 , and two washers and O-rings (not shown). Again, these connection devices can accommodate two different orientations of the canister air cleaner  4  with respect to the engine  20  based upon the rotational positioning of the elbow  38  with respect to the second carburetor air inlet  14  and the rotational positioning of the rubber hose  44  with respect to the elbow  38 .  
         [0008]     Although the first and second sets of connection devices  12 , 16  adequately communicate filtered air from the canister air filter  4  to the first and second carburetor air inlets  8  and  14 , respectively, these connection devices nevertheless have certain disadvantages. First of all, the numbers of pieces employed by each of the first and second sets of connection devices  12 , 16  are relatively large, which renders those sets of connection devices fairly complicated and expensive to manufacture and assemble. Second, certain junctions among the different connection devices constitute potential air leakage paths, which are disadvantageous insofar as they potentially allow unfiltered air to bypass the canister air cleaners and directly enter the engine carburetors. In particular, the junctions between the gaskets  24 , 40  and the connection devices on either sides of the gaskets (e.g., the adapters  26  and  42  and the elbows  22  and  38 , respectively) can potentially allow for air leakage.  
         [0009]     Further, the first and second sets of connection devices  12 , 16  are disadvantageous insofar as, due to their large numbers of parts, it is difficult to assemble the connection devices with one another and to the carburetor air inlets  8 , 14  in a consistent manner that guarantees consistent air flow into the carburetors and thus consistent engine performance. As a result, during installation, significant efforts typically need to be made in order to properly align and calibrate the connection devices in relation to the carburetor air inlets  8 , 14  so that desired air flow occurs. Indeed, in certain embodiments, specialized features must be machined into the connection devices to facilitate their calibration in order to guarantee desired air flow.  
         [0010]     Further, the difficulties associated with proper assembly and calibration of the connection devices are exacerbated when those devices are modified in their assembly and configuration to adjust for different orientations of the canister air cleaner  4  as discussed above. Reorientation of the elbows  22 , 38  in particular can affect the calibration of the connection devices so as to negatively affect desired air flow patterns into the engine carburetors.  
         [0011]     It therefore would be advantageous if new connection device(s) could be designed for linking the output terminals of canister air cleaners (or other air filtration devices) with the air inlets of carburetors. It particularly would be advantageous if such new connection device(s) had fewer parts than the aforementioned devices, so as to reduce manufacturing and installation costs and difficulties, and so as to reduce or eliminate undesirable potential air leakage paths. Further, it would be advantageous if such new connection devices continued to make it possible to couple carburetors to canister air cleaners (or other air filtration devices) having multiple (at least two) orientations. Additionally, it would be advantageous if such new connection devices were designed so as to provide desired air flow patterns into the carburetors without requiring significant calibration efforts during installation or requiring special calibration features.  
       SUMMARY OF THE INVENTION  
       [0012]     The present inventor has recognized that canister air cleaners (or other air filtration devices) can be coupled to engine carburetors in a much simpler manner than the Prior Art embodiments discussed above, through the use of only a single adapter element configured to directly interface a carburetor air inlet, and a single rubber hose having two bends for linking the adapter element to the canister air cleaner. The exact adapter element varies depending upon whether it is to be used in relation to horizontal-shaft engines and vertical-shaft engines. For horizontal-shaft engines, the adapter element includes merely a single, generally-straight tubular section while, for vertical-shaft engines, the adapter element would include merely a single 90 degree tubular elbow. In each case, the portion of the adapter element to be mounted immediately adjacent to the carburetor element includes a relatively long, straight tubular section.  
         [0013]     In each case, the number of parts needed to couple the canister air cleaner and engine carburetor is small, thus minimizing manufacturing and installation cost and reducing the possibility of air leakage. Further in each case, the adapter can be used to couple its respective carburetor air inlet to a canister air cleaner when the canister air cleaner is in either of two orientations, without adjusting the position of the adapter relative to the carburetor air inlet, through the use of an appropriate single rubber hose. Because the adapter need not be moved with respect to the carburetor air inlet to accommodate changes in positioning of the canister air cleaner, and because each adapter includes the relatively long, straight tubular section immediately adjacent to the carburetor air inlet, desired air flow patterns can be consistently provided into the carburetor without significant efforts at calibrating or aligning the connection devices with the carburetor air inlet, and without other special calibration features machined on the adapter elements.  
         [0014]     In particular, the present invention relates to an assembly of components for coupling an air filtration device to an engine. The assembly includes an adapter component having first and second adapter ends, and a hose having first and second bends and first and second hose ends, where the first hose end is configured for being coupled to an output terminal of the air filtration device and the second hose end is capable of being coupled to the first adapter end of the adapter component. The adapter component further includes a straight tubular section leading up to the second adapter end so that, when the adapter component is assembled with respect to the engine, air is directed from the straight tubular section into the engine.  
         [0015]     The present invention further relates to an internal combustion engine that includes an air filtering device, a carburetor, and a set of connection devices for coupling an output terminal of the air filtering device to an air inlet of the carburetor. The set of connection devices includes a hose and an adapter component, where the adapter is directly coupled to the air inlet and the hose is directly coupled between the output terminal and the adapter component. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of an exemplary horizontal-shaft internal combustion engine on which is mounted a canister air cleaner, where the engine&#39;s carburetor and the air cleaner are coupled to one another by a first set of Prior Art connection devices;  
         [0017]      FIG. 2  is a perspective, exploded view of the first set of connection devices of  FIG. 1 ;  
         [0018]      FIG. 3  is a perspective view of an exemplary vertical-shaft internal combustion engine on which is mounted a canister air cleaner, where the engine&#39;s carburetor and the air cleaner are coupled to one another by a second set of Prior Art connection devices;  
         [0019]      FIG. 4  is a perspective, exploded view of the second set of connection devices of  FIG. 3 ;  
         [0020]      FIG. 5  is a perspective view of an exemplary horizontal-shaft internal combustion engine shown in cutaway on which is mounted a canister air cleaner, where the engine&#39;s carburetor and the air cleaner are coupled to one another by a first set of connection devices in accordance with one embodiment of the present invention;  
         [0021]      FIG. 6  is a perspective, exploded view of the first set of connection devices of  FIG. 5 ;  
         [0022]      FIG. 7  is a perspective view of an adapter element of the first set of connection devices of  FIGS. 5-6 ;  
         [0023]      FIGS. 8-13  are elevation views of various surfaces of the adapter element of  FIG. 7 ;  
         [0024]      FIG. 14  is a cross-sectional view of the adapter element taken along line  14 - 14  of  FIG. 9 ;  
         [0025]      FIG. 15  is a perspective view of an exemplary vertical-shaft internal combustion engine shown in cutaway on which is mounted a canister air cleaner, where the engine&#39;s carburetor and the air cleaner are coupled to one another by a second set of connection devices in accordance with another embodiment of the present invention;  
         [0026]      FIG. 16  is a perspective, exploded view of the second set of connection devices of  FIG. 15 ;  
         [0027]      FIG. 17  is a perspective view of an adapter element of the second set of connection devices of  FIGS. 15-16 ;  
         [0028]      FIGS. 18-23  are elevation views of various surfaces of the adapter element of  FIG. 17 ; and  
         [0029]      FIG. 24  is a cross-sectional view of the adapter element taken along line  24 - 24  of  FIG. 19 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]     Referring to  FIG. 5 , a canister air cleaner  50  is shown to be mounted on an exemplary horizontal-shaft internal combustion engine  52  (shown in cutaway), which for example could be a Command Twin engine manufactured by Kohler Co. as discussed above with respect to  FIG. 1 . An air output terminal  54  of the air cleaner  50  is coupled to a carburetor air inlet (not shown) of the engine  52  by way of a first set of connection devices  56 .  
         [0031]     As shown more clearly in  FIG. 6 , the first set of connection devices  56  includes a first adapter element  58  and a first rubber hose  60 . The rubber hose  60  can be made from any rubber-type or elastomeric or flexible material and, as shown, is molded to have first and second bends  62  and  64 , respectively. In certain embodiments, the hose  60  has a 2″ inside diameter. A first end  66  of the hose  60  fits onto the air output terminal  54  of the air cleaner  50  while a second end  68  of the hose is configured to fit onto an oval-shaped end  70  of the adapter element  58 .  
         [0032]     More specifically, the oval-shaped end  70  of the adapter element  58  includes a lip  84  and a flange  86 . In addition to being secured with respect to the oval-shaped end  70  simply by way of tension (due to being forced to take on an oval shape), the second end  68  of the rubber hose  60  is secured with respect to the oval-shaped end due to the additional pressure created by the lip  84  with respect to the rubber hose  60 . The interaction of the second end  68  with the lip  84  not only serves to secure the rubber hose  60  to prevent the hose from falling off of the oval-shaped end  70  (e.g., when an additional clamp is placed on the hose), but also serves to prevent air leakage. As for the flange  86 , that flange serves as a positive stop for the second end  68  of the rubber hose  60  as it is placed over the oval-shaped end  70 . Additionally, each of the lip  84  and the flange  86  serve as stiffening ribs that help to maintain the oval shape of the oval-shaped end  70 .  
         [0033]     The adapter element  58  as shown in  FIGS. 6-14  generally is a straight tubular section that extends from the oval-shaped end  70  to an opposite end  72  at which is located a flange  74  designed to interface the carburetor air inlet of the engine. The flange  74  includes two screw holes  76  through which can be placed two screws  78  (see  FIG. 5 ), by which the flange  74  can be attached to a carburetor air inlet. The flange  74  can, depending upon the embodiment, directly interface the carburetor air inlet or interface the carburetor air inlet with a gasket (not shown) disposed in between. The attachment of the flange  74  to the carburetor air inlet by way of the screws  78  is facilitated by the oval-shape of the oval-shaped end  70 , since screw holes  76  are not covered over by any portion of the end  70  (as best shown in  FIG. 9 ).  
         [0034]     The adapter element  58  further includes a nipple  80  to which can be affixed a breather tube  82 . The nipple  80  includes a lip  88  that serves to retain the breather hose  82  in the same manner as the lip  84  serves to retain the rubber hose  60 , thus further preventing the entry of undesirable material (e.g., dirt) from entering the adapter element  58  and then the carburetor. The adapter element  58  can be made from a variety of materials and, in one embodiment, is constructed from glass-filled polypropylene, which is satisfactory in view of the fact that the adapter element is unlikely to be exposed to extremely high temperatures and in view of its relatively high stiffness and relatively low cost.  
         [0035]     Depending upon the orientation of the canister air cleaner  50  with respect to the engine  52 , a different rubber hose  60  is used. In particular, when the canister air cleaner  50  is oriented as shown in  FIG. 5 , the hose  60  shown in  FIGS. 5-6  is utilized; however, when the canister air cleaner  50  is oriented oppositely to that shown in  FIG. 5  (e.g., by rotating the air cleaner 180 degrees), a hose having a shape being the mirror image of that shown in  FIGS. 5-6  would be utilized.  
         [0036]     Through the use of the appropriate hose depending upon the orientation of the air cleaner  50 , the air cleaner can be coupled to the adapter element  58  and thus to the carburetor air inlet without any additional adjustment, rotation, or other movement of the adapter element relative to the carburetor air inlet. Therefore, the manner of assembly of the first set of connection devices  56  in relation to the canister air cleaner  50  and the engine carburetor is highly standardized. Further, adjustments in the orientation of the canister air cleaner are possible without impacting any calibration or positioning of the adapter element that might negatively or otherwise affect the manner of air flow into the carburetor.  
         [0037]     Additionally, because the first set of connection devices  56  includes only the adapter element  58  and the rubber hose  60  (and also the breather hose  82  and screws  78 ), the first set of connection devices has a minimal number of parts and consequently is relatively inexpensive and simple to manufacture and install relative to the Prior Art set of connection devices discussed with reference to  FIGS. 1-2 . Further, due to the minimization of parts, there is relatively little (if any) chance that unfiltered air can be communicated to the carburetor air inlet without being filtered by the canister air cleaner  50 .  
         [0038]     Referring particularly to  FIG. 14 , it is further evident that the inner cross-section of the adapter element  58  forms a tube  90 . Although the tube  90  varies from having an oval cross-section at the oval-shaped end  70  to having a circular cross-section at the flange  74 , the tube nevertheless follows a straight path along its central axis  92  and is relatively long (e.g., at least two inches long).  
         [0039]     As a result of the tube being straight and relatively long, along with the fact that (as discussed above) the adapter element  58  is intended to be affixed to the carburetor air inlet in only one standardized manner, air flow into the carburetor air inlet from the adapter element proceeds in a consistent, straight manner as desired. That is, in many cases, neither significant calibration operations, nor any significant specialized machined features along the inside of the tube  90  or the flange  74  interfacing the carburetor air inlet, is necessary in order to achieve desired air flow into the carburetor air inlet. Further, to the extent that some calibration of the adapter element  58  in relation to the carburetor air inlet (or of the carburetor) is required in certain circumstances, that calibration need only be performed once even though the canister air cleaner is replaced or changed in its configuration at a later date.  
         [0040]     Turning to  FIG. 15 , an alternate exemplary embodiment of the present invention for implementation in combination with a vertical-shaft (rather than horizontal-shaft) internal combustion engine  94  is shown. More particularly as shown, the air output terminal  54  of the air cleaner  50  in the present embodiment is coupled to a carburetor air inlet (not shown) of the vertical-shaft internal combustion engine  94  by way of a second set of connection devices  96 .  
         [0041]     Referring further to  FIG. 16 , the second set of connection devices  96  includes a second adapter element  98  and a second rubber hose  100 . The rubber hose  100  can be made from any rubber-type or elastomeric or somewhat-flexible material and, as shown, is molded to have first and second bends  102  and  104 , respectively. A first end  106  of the hose  100  fits onto the air output terminal  54  of the air cleaner  50  while a second end  108  of the hose is configured to fit onto a circularly-shaped end  110  of the adapter element  98 , which in the present embodiment (though not necessarily) has an outer diameter of 50.8 mm.  
         [0042]     More specifically, the circularly-shaped end  110  of the adapter element  98  includes first and second ears  124  and  126 , respectively (see, e.g.,  FIG. 19 ). The second end  108  of the rubber hose  60  is secured with respect to the circularly-shaped end  110  by way of tension (due to being forced over the end  110 ), which serves to prevent air leakage and serves to prevent the hose from falling off the end  110  (e.g., when a clamp is secured). The ears  124 ,  126  serve as positive stops for the second end  108  of the rubber hose  100  as it is placed over the circularly-shaped end  110 .  
         [0043]     The adapter element  98  as shown in  FIGS. 16-24  generally is a 90-degree elbow-shaped tube (or simply “elbow”). More specifically, the adapter element  98  has a first tubular segment  111  and a second tubular segment  113  that are connected with one another by a junction  114  (see, e.g.,  FIG. 24 ). The first tubular segment  111  extends from the circularly-shaped end  110  to the junction  114 , while the second tubular segment  113  extends from the junction  114  to an opposite end  112  that is designed to interface the carburetor air inlet of the engine. In the present embodiment, the first and second tubular segments  111 , 113  have respective axes that are substantially perpendicular to one another, although in alternate embodiments, the respective axes of the two segments could be oriented in different manners (e.g., depending upon how the canister air cleaner is intended to be mounted onto the engine and how the rubber hose  100  is configured).  
         [0044]     Along first and second sides  115  and  117  of the second tubular segment  113  are screw slots  116  through which can be placed two screws  118  (see  FIG. 15 ), by which the opposite end  112  can be attached to a carburetor air inlet. The end  112  can, depending upon the embodiment, directly interface the carburetor air inlet or interface the carburetor air inlet with a gasket (not shown) disposed in between.  
         [0045]     The adapter element  98  further includes an orifice  120  to which can be affixed a breather tube  122 . In alternate embodiments, a nipple such as that discussed with reference to  FIGS. 6-14  could be used in place of the orifice  120 . The adapter element  98  can be made from a variety of materials and, in one embodiment, is constructed from cast aluminum, which is appropriate in view of the fact that this adapter element may be exposed to fairly high temperatures in view of its possible positioning above a muffler. In alternate embodiments, a plastic material capable of withstanding high temperatures could be employed.  
         [0046]     Depending upon the orientation of the canister air cleaner  50  with respect to the engine  94 , a different rubber hose  100  is used. In particular, when the canister air cleaner  50  is oriented as shown in  FIG. 15 , the hose  100  shown in  FIG. 15  is utilized; however, when the canister air cleaner  50  is oriented oppositely to that shown in  FIG. 15  (e.g., by rotating the air cleaner 180 degrees), a hose having the shape shown in  FIG. 16  (namely, a shape that is the mirror image of that shown in  FIGS. 15 ) would be utilized.  
         [0047]     Through the use of the appropriate hose depending upon the orientation of the air cleaner  50 , the air cleaner can be coupled to the adapter element  98  and thus to the carburetor air inlet without any additional adjustment, rotation, or other movement of the adapter element relative to the carburetor air inlet. Therefore, the manner of assembly of the second set of connection devices  96  in relation to the canister air cleaner  50  and the engine carburetor is highly standardized. Further, adjustments in the orientation of the canister air cleaner are possible without impacting any calibration or positioning of the adapter element that might negatively or otherwise affect the manner of air flow into the carburetor.  
         [0048]     Additionally, because the second set of connection devices  96  includes only the adapter element  98  and the rubber hose  100  (and also the breather hose  122  and screws  118 ), the second set of connection devices has a minimal number of parts and consequently is relatively inexpensive and simple to manufacture and install relative to the Prior Art set of connection devices discussed with reference to  FIGS. 3-4 . Further, due to the minimization of parts, there is relatively little (if any) chance that unfiltered air can be communicated to the carburetor air inlet without being filtered by the canister air cleaner  50 .  
         [0049]     As discussed above, the tubular segment  113  is a relatively straight tubular section, and has a relatively long length (e.g., two or more inches). As a result of the tubular segment  113  being straight and relatively long, along with the fact that (as discussed above) the adapter element  98  is intended to be affixed to the carburetor air inlet in only one standardized manner, air flow into the carburetor air inlet from the adapter element proceeds in a consistent, straight manner as desired. That is, in many cases, neither significant calibration operations, nor any significant specialized machined features along the inside of the tubular segment  113  interfacing the carburetor air inlet, is necessary in order to achieve desired air flow into the carburetor air inlet. Further, to the extent that some calibration of the adapter element  98  in relation to the carburetor air inlet is required in certain circumstances, that calibration need only be performed once even though the canister air cleaner is replaced or changed in its configuration at a later date.  
         [0050]     While the foregoing specification illustrates and describes the preferred embodiments of this invention, it is to be understood that the invention is not limited to the precise construction herein disclosed. The invention can be embodied in other specific forms without departing from the spirit or essential attributes. For example, the present inventive connection devices could potentially be employed for the purpose of coupling engine carburetors with other air filtration devices rather than merely canister air cleaners as shown. Also, certain features could be varied from those shown depending upon the embodiment. For example, in some embodiments, the oval-shaped end  70  could be replaced with a circularly-shaped end. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.