Abstract:
A clutch cover for use with virtually any combination of make and model of engine components and method of making the same is disclosed. The clutch cover is made by spin forming a sheet of metal and removing material as needed to coincide with the corresponding engine components. Therefore, the exact design of the cover including attaching holes and apertures related to release levers may be quickly and easily formed in the clutch cover. Furthermore, a heat management system is provided that includes the addition of fins or other apertures through the clutch cover to increase the air flow to reduce the temperature within the clutch cover to cool engine components.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 of a provisional application Ser. No. 61/436,433 filed Jan. 26, 2011, which application is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is generally related to a clutch assembly. More particularly, but not exclusively, the invention relates to an improved clutch assembly cover and a method of making the cover, as well as an optional heat management feature that can be included with the cover. 
       BACKGROUND OF THE INVENTION 
       [0003]    As is well known, clutches for vehicles operate to selectively couple and decouple an engine to a transmission for the purpose of starting the vehicle movement while the engine is in gear, bringing the vehicle to a stop while the engine is running, changing gears while the vehicle is in motion and putting the vehicle in motion from a dead stop. Conventional clutches include a cover assembly having an annular cover or housing and an annular pressure plate connected to the cover for conjoint rotation with the cover. The cover is fixedly attached to a flywheel driven by the vehicle engine, so that the pressure plate is located between the cover and the flywheel. Attachment of the cover to the flywheel is by a plurality of bolts, which space the cover and pressure plate from the flywheel. 
         [0004]    A drive shaft is received through the cover assembly and flywheel free of fixed connection to any of these so that absent action of the clutch, the drive shaft and flywheel rotate independently of each other. The drive shaft is splined and one or more clutch friction discs are mounted on the splines for conjoint rotation with the drive shaft, while being free to slide longitudinally on the drive shaft. The clutch friction discs are positioned between the pressure plate and the flywheel. Heat shields are disposed between the pressure plate and nearest friction disc, and also between the flywheel and nearest friction disc. Floater plates are disposed between adjacent friction discs. 
         [0005]    Springs between the cover and pressure plate force a ring away from the cover to clamp the friction discs against the flywheel. The clamping action mates the drive shaft and flywheel for conjoint rotation so that the drive shaft is driven by the engine. However, some relative rotation or sliding between the friction discs and flywheel desirably occurs before there is conjoint rotation to reduce the impact loads on the engine and drive shaft as well as to make the motion of the vehicle smoother. 
         [0006]    The clutch is released to permit independent rotation of the flywheel and drive shaft by a mechanical linkage. Levers pivotally mounted on the cover are connected to pins fixedly attached to the pressure plate. The levers may be engaged by a release member of the mechanical linkage to pull the pressure plate toward the cover against the force of the springs to release the clutch. 
         [0007]    The cover protects the clutch and flywheel from being obstructed by foreign elements. The cover also provides a barrier to access within the clutch assembly to prevent accidental contact with the fast-spinning parts within the clutch assembly. A typical clutch cover is stamped or cast metal. The shapes can vary depending on a number of factors including type and manufacturer of clutch. 
         [0008]    However, casting and stamping requires the use of an expensive mold, and a new mold is required for each type or style of cover. One type or style of cast or stamped cover only fits one type or brand of motor or car, and is not transferrable between different automobiles or engines. Multiple molds increase costs greatly. In addition, special strengthening methods must be incorporated, such as having a greater thickness of metal, more metal material, special structural features, or the like. The strengthening is due to casting or stamping and the stresses experienced by the cover. The strengthening methods can add weight, increase the size, and otherwise be antagonistic to efficiency and economy of manufacturing the cover, use of space on the automobile, and operation of the automobile. 
         [0009]    It is therefore a primary object, feature, and/or advantage of the present invention to provide an apparatus and method that improves over the deficiencies in the art. 
         [0010]    It is another object, feature, and/or advantage of the present invention to provide an improved clutch cover and method of making the same that is lighter in weight than prior art clutch covers. 
         [0011]    It is another object, feature, and/or advantage of the present invention to provide an improved clutch cover and method of making the same that has a smaller profile from the plane of a mounting flange to the plane at the opposite side of the cover. 
         [0012]    It is another object, feature, and/or advantage of the present invention to provide an improved clutch cover and method of making the same that occupies less space to be able to fit more clutch lining layers on the clutch disc to better handle higher horsepower engines. 
         [0013]    It is another object, feature, and/or advantage of the present invention to provide an improved clutch cover and method of making the same that is less expensive than a die cast stamp, mold, or form. 
         [0014]    It is another object, feature, and/or advantage of the present invention to provide an improved clutch cover and method of making the same that includes an optional heat management feature that can deter damage or deterioration of the clutch plates due to increased heat. 
         [0015]    These and/or other objects, features, and advantages of the present invention will be apparent to those skilled in the art. The present invention is not to be limited to or by these objects, features and advantages. No single embodiment need provide each and every object, feature, or advantage. 
       SUMMARY OF THE INVENTION 
       [0016]    According to one aspect of the present invention, a clutch cover for connecting a clutch assembly to a flywheel of an engine is provided. The clutch cover includes a bowl-shaped member having an axis, a wide end, a narrow end, and an aperture through the narrow end along the axis. The bowl-shaped member is formed by deforming a spinning sheet of metal. A flange extends about the wide end of the bowl-shaped member. A rim is formed at the narrow end of the bowl-shaped member adjacent the aperture. A pattern of holes is machined in the flange and the rim, with the pattern of holes determined by the type of engine used. A plurality of apertures is formed through the bowl-shaped member and is configured to house release levers of a pressure plate assembly. 
         [0017]    According to another aspect of the present invention, a method of forming a universal clutch cover for use with a clutch assembly used with virtually any make of vehicle engine is provided. The method includes determining the make of the vehicle engine. A force is applied normal to a spinning sheet of metal having an aperture therethrough to form a generally bowl-shaped member with a flange at a wide end and a rim at a narrow end of the bowl-shaped member. A pattern of holes is machined in the flange of the bowl-shaped member, with the pattern of holes corresponding to the make of the vehicle engine. A plurality of apertures is machined through the bowl-shaped member between the flange and the rim. 
         [0018]    According to yet another aspect of the present invention, a method of forming a clutch cover for a clutch assembly of an engine is provided. The method includes forming a hole in a sheet of metal. The sheet of metal is spun on a spin-casting machine about the central axis of the hole. A force is applied normal to the sheet of metal starting at a predetermined distance from the edge of the hole to form a bowl-shaped member having a rim adjacent a narrow end and a flange adjacent a wide end, with the rim and flange being generally perpendicular to the axis of the hole. A pattern of flange holes is machined in the flange, wherein the pattern of flange holes are configured to operably attach the clutch assembly to the engine. A plurality of apertures is cut in the bowl-shaped member, the apertures adapted to house release levers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is an exploded view of components of a vehicle engine, including an engine block, flywheel, clutch assembly, and bell housing. 
           [0020]      FIG. 2  is a perspective view of a clutch assembly used in vehicles. 
           [0021]      FIG. 3  is an exploded view of the clutch assembly of  FIG. 2 . 
           [0022]      FIG. 4  is a perspective view of a clutch cover according to the present invention. 
           [0023]      FIG. 5  is a bottom view of the clutch cover of  FIG. 4 . 
           [0024]      FIG. 6  is a side view of the clutch cover of  FIG. 4 . 
           [0025]      FIG. 7A  shows a method of forming the clutch cover by use of an internal spin forming machine. 
           [0026]      FIG. 7B  shows a method of forming the clutch cover by use of an external spin forming machine. 
           [0027]      FIG. 8  shows the steps of a process of forming the clutch cover according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]      FIG. 1  is an exploded view of components of a vehicle engine, including an engine block  30 , a flywheel  32 , a clutch disc  28 , a clutch assembly  10 , and a bell housing  31 . The flywheel  32  is connected to the engine  30  and the clutch assembly  10  is connected to the flywheel  32  with the clutch disc  28  therebetween. As is known in the art, the clutch assembly  10  works with the clutch disc  28  to selectively press the clutch disc  28  against the flywheel  32  in order to power a vehicle. Furthermore, the flywheel  32 , clutch disc  28  and clutch assembly  10  are confined within the bell housing  31 , which is attached to the engine  30 . Therefore, it should be understood that the clutch assembly  10  ideally has a low height in order to take up the least amount of room within the bell housing  31  and to keep the engine  30  from getting too large. 
         [0029]      FIG. 2  is a perspective view of a clutch assembly  10  as taken from  FIG. 1  and used in vehicles. As stated above, the clutch assembly  10  is used to selectively engage a clutch disc  28  with a flywheel  32  in an engine to both allow the automobile vehicle to idle without having to power down, and to provide power to the wheels of the vehicle in order to drive said vehicle. Previously, the clutch assembly  10  has been engine specific. For example, a certain clutch assembly  10  must be used with a certain engine  30 , e.g., a Chevrolet manufactured engine requires the use of a Chevrolet clutch assembly. The clutch requirements make it difficult for automobile enthusiasts to interchange engine components as they may like. As shown in  FIG. 2 , the clutch assembly  10  includes at least a clutch cover  12  and a pressure plate assembly  14  attached to the clutch cover  12 . 
         [0030]      FIG. 3  shows an exploded view of the clutch assembly  10  of  FIG. 2 . The clutch assembly  10  includes a clutch cover  12 , a pressure plate assembly  14 , a spring retainer  16 , and a plurality of blocks  18  or other means of attaching the clutch cover  12  to the pressure plate assembly  14 . 
         [0031]    The pressure plate assembly  14  generally includes a pressure plate  20 , a plurality of springs  22  positioned radially on the pressure plate  20 , as well as a plurality of pivots  24  and release levers or arms  26  positioned radially on the pressure plate  20 . The springs and release arms are configured to selectively engage the clutch disc  28  into contact and from contact with the flywheel  32  via the pressure plate  20 . Therefore, the number and arrangement of springs and release arms may vary depending on the type of vehicle. For instance, racing vehicles or vehicles having a higher torque and horsepower may require more release arms than would a standard vehicle used on public roads. Therefore, the present invention contemplates that the number of release arms may vary as is known and used in the industry. However, it is noted that most vehicles will use between three and ten release arms. 
         [0032]    Positioned between the pressure plate assembly  14  and the clutch cover  12  is a spring retainer  16 . The spring retainer  16  helps align the springs  22  of the pressure plate assembly  14  and prevents the springs from being diverted from their line of axis. The spring retainer  16  is housed within the clutch cover  12 . Also shown in  FIG. 3  is a plurality of blocks  18  operatively attached to the clutch cover  12 . The blocks  18  align with the pivots  24  of the pressure plate assembly  14  to attach the clutch cover  12  to the pressure plate assembly  14 . Therefore, the number of blocks  18  will correspond to the number of release arms  26  used with the vehicle. 
         [0033]      FIG. 4  is a perspective view of a clutch cover  12  according to the present invention. It should be noted that the clutch cover  12  may also be known as a clutch housing or clutch hat. The clutch cover  12  includes a generally bowl-shaped member  34  having a wide end  38  and a narrow end  40 . Adjacent the wide end  38  and extending therefrom is a flange  42 . Adjacent the narrow ends  40  and extending generally inwardly towards an axis  62  of the bowl-shaped member  34  is a rim  44 . On the flange is a pattern of flange holes  46  that correspond to the flywheel  32  of an engine. On the rim  44  is a pattern of rim holes  48  that corresponds with the bell housing  31  for attaching the clutch assembly  10  to the bell housing  31 . Therefore, the flange holes  46  and rim holes  48  will be make or model specific, and will be determined by the make and model of the engine that the clutch assembly  10  will be used with. Furthermore, the clutch cover  12  includes a plurality of lever arm apertures  50  through the bowl-shaped member  34  and partially through the rim  44 . The lever arm apertures  50  correspond to the lever or release arms  26  of the pressure plate assembly  14 . Therefore, the number of lever arm apertures  50  will depend on the number of release levers or arms  26  used with the clutch assembly  10 . Further shown in  FIG. 4  is a plurality of bent segments or fins  52  positioned radially about the clutch cover  12 . The fins  52  are bent segments  54  of the bowl-shaped member  34 , and are used to provide a heat management aspect of the invention, as will be described in greater detail below. 
         [0034]      FIGS. 5 and 6  are a bottom view and side view of the clutch cover  12  of  FIG. 4 . The clutch cover  12  of the present invention is spun cast. The spin casting of the clutch cover  12  allows the clutch cover  12  to be manufactured quicker and cheaper than existing methods. Furthermore, the spin casting allows the clutch cover  12  to be generally a universal-type clutch cover that can be used with any make or model of engine, flywheel, and bell housing.  FIGS. 5 and 6  show a few more of the details of the clutch cover  12 . 
         [0035]    For instance, it should be noted that the rim  44  and flange  42  are generally planar and parallel to one another. This allows the clutch cover  12  to be easily mounted in an engine. Furthermore, it should also be noted that the clutch cover  12  includes a generally first section  56  at the wide end  38  of the clutch cover  12  and a second section  58  at the narrow end  40  of the clutch cover  12 . The second section  58  of the clutch cover  12  is generally perpendicular to the flange  42  and rim  44  of the clutch cover  12 . The height of the second section  58  may also be varied according to the specific type of vehicle and engine. It should be noted that spin coating produces a clutch cover with greater strength, and that the spin cast cover can be lower in height due to the greater strength. 
         [0036]      FIGS. 7A and 7B  show alternative methods of spin forming a sheet of steel or metal  60  into the bowl-shaped member  34  for use as a clutch cover  12 .  FIG. 7A  shows the use of an external-type spin forming and  FIG. 7B  shows the use of an internal-type spin forming. 
         [0037]      FIG. 7A  shows the method of forming the clutch cover  12  by use of an external spin forming machine  64 . A sheet of metal  60  with a hole or aperture  36  therethrough placed onto a spinning machine  64  with the axis of the sheet of metal passing through the axis  62  of the spinning machine  64  itself. The sheet  60  is then secured by a support  68  and spun at a very high speed. As the sheet  60  spins, a roller  70  exerts a force downward onto the sheet  60  forcing it to form about a mandrel  74  with a flange  42  formed at the wide end of the bowl-shaped member  34 . However, as shown in  FIG. 7A  according to the dashed lines, as the roller  70  exerts a force normal to the sheet  60  of the mandrel  74 , the flange  42  may not be level or parallel with the rim  44 . Therefore, this method may require the use of a leveling machine or other method for leveling the flange  42  to the rim  44 . 
         [0038]      FIG. 7B  shows an internal-type spin forming. A sheet of metal  60  is placed onto the spinning machine  64  with the axis  62  of the spinning machine  64  inserted through an aperture  36  in the center of the sheet of metal  60 . The sheet  60  is then secured to the spinning machine  64  by the use of a support  68 . The s spinning machine  64  then spins the sheet  60  at a high speed, and a roller  70  exerts a force generally normal to the sheet  60 . The force exerted by the roller  70  causes the sheet to form into the cavity  72 . Therefore, the shape of the spun sheet of metal will coincide to the shape of the cavity  72  of the spinning machine  64 . Furthermore, the cavity  72  and the initial position of the roller  70  may be determined such that a flange  42  is left at the wide end of the spun sheet of metal  60  as is required for the clutch cover  12 . Once the sheet  60  has been spun to form the bowl-shaped member  34 , the flange  42  may be leveled as needed to make it parallel to the rim  44  of the clutch cover  12 . 
         [0039]      FIG. 8  shows a series of steps of a process of forming the clutch cover  12  according to the present invention. The clutch cover  12  starts with a single sheet  60  of metal, such as steel. Next, an aperture  36  is formed in the center of the sheet  60 , with the aperture serving as an indexing hole to be placed on the spin casting machine. Therefore, for the present invention, it is preferred that the aperture  36  be formed in the center of the sheet of metal  60 . The sheet  60  is then spun cast on a spinning machine  64  as disclosed according to one of the methods as disclosed in either  FIG. 7A  or  7 B. Thus, the bowl-shaped member  34  may be formed by either external or internal spin casting. After this step, the bowl-shaped member  34  will have a flange  42  and the beginnings of a rim  44 . It should be noted that the spinning may form a general bowl-shaped member  34  as shown in  FIG. 8  or may use a spin cast machine having the shape of the clutch cover  12  as shown in the next step. Therefore, the beginnings of the clutch cover  12  shape may be formed. 
         [0040]    In the fourth step shown in  FIG. 8 , the bowl-shaped member  34  is formed to have a flange  42 , a rim  44 , and the bowl-shaped body therebetween. The bowl-shaped body includes a first section  56  at the wide end of the bowl-shaped member  34  and a second section  58  adjacent the narrow portion of the bowl-shaped member  34 . As described above, the second section  58  of the bowl-shaped member  34  may be generally perpendicular to the rim and flange of the member. Furthermore, as shown in this step, the flange has been machined or laser cut to have a specific peripheral shape. The peripheral shape is determined by the make and model of the engine. Next, material is removed from the bowl-shaped member  34 . For instance, a pattern of flange holes  46  and rim holes  48  are machined into the member. The flange holes  46  and rim holes  48  are selected depending on the make and model of the engine in which the clutch cover  12  will be used. Additionally, a plurality of lever arm apertures  50  are formed in the bowl-shaped member  34 . The number and location of the lever arm apertures  50  will depend on the pressure plate assembly  14  used with the clutch cover  12 . This may also depend on the intended use of the clutch assembly  10 . Finally, a plurality of fins  52  may be stamped in the bowl-shaped member  34  or clutch cover  12  body. The fins  52  are bent segments of the clutch cover  12  body. The fins  52  may be stamped by a stamping machine. However, it should be noted that the fins  52  are bent segments  54  comprising the material of the clutch cover  12  bent at least partially away from the axis of the clutch cover  12  such that there is a slight opening from the outside of the clutch cover  12  to the inside of the clutch cover  12 . The fins  52  provide a heat management system for the clutch assembly  10 . 
         [0041]    As stated above, the method of manufacturing the clutch cover  12  of the present invention provides for many benefits over the prior art. By spin casting the clutch cover  12 , the exact design of the clutch cover  12  may be varied on a case by case basis. For instance, many automobile enthusiasts would like to use different engine components than what is provided by the manufacturer of the vehicle. This might be known as after-market parts. Therefore, enthusiasts may wish to use a Chevrolet engine with a Ford transmission. Presently, there is difficulty in connecting the different types of engines and transmissions. This is due to the fact that each manufacturer has certain attaching features that do not coincide with another manufacturer. Therefore, in order to connect the two, specialty components such as bell housings and clutch covers are needed. However, due to the price of molds that are presently used to manufacture the clutch covers, this is not economically feasible. Therefore, the spin casting and machining of the clutch cover  12  according to the present invention allows for this to become a reality. 
         [0042]    The spin forming also adds strength to the clutch cover  12  compared to hydroforming the cover. The added strength allows the cover to be thinner, which also means lighter. Furthermore, the lower clearance allows for the clutch assembly  10  to use more clutch discs than previously, which aids in the engine efficiency. 
         [0043]    The method of manufacturing the clutch cover  12  as described above would allow for a mere universal combination of engine components. For instance, a customer may wish to include two different makes of engine and transmission. Once the make and model of engine and transmission are known, the present invention will allow for a quick and inexpensive way to provide for a clutch cover for use with the different makes and models of transmission and engine. Furthermore, the invention contemplates the use of a database that includes specifications for different types of engines, bell housings, transmissions, and other engine components related to the clutch assembly  10 . Therefore, a user would simply select the desired engine components from said database, and the clutch cover  12  would be manufactured to accommodate the selected engine components. This may include the pattern of rim holes, pattern of flange holes, number and location of lever arm apertures, height of clutch cover, and number and location of fins. 
         [0044]    Furthermore, the fins  52  aid in the heat management of the clutch assembly  10 . One problem with current clutch assemblies is the damage due to overheating of the assemblies. The heat produced by the spinning components of the engine may cause components to be damaged. For example, clutch discs are commonly warped after extended use due to the heat produced by the spinning components of the engine. Thus, the clutch disc must be replaced in order to provide efficient operation of the engine and vehicle. However, the fins  52  will work similar to a fan in bringing outside air to within the clutch cover  12  to aid in cooling of the clutch discs  28  and other components within the clutch assembly  10 . The clutch assembly  10  is always spinning. Thus, the spinning of the clutch cover  12  and fins  52  located on the clutch cover  12  will draw in air from outside the clutch cover  12  to aid in the cooling of the clutch disc  28 . The cooling of the clutch disc  28  will extend the life of said clutch disc  28  and provide for prolonged efficiency of a vehicle engine. Therefore, it should be appreciated that the design of the fins  52  may vary. 
         [0045]    As shown in the Figures, the fins  52  are generally bent segments  54  of the clutch cover  12  material bent outwardly from the axis  62  through the clutch cover  12 . However, the fins  52  may be bent inwardly, or may be rotated 90° relative to the flange  42  to have different configurations to draw in more or less air for the clutch assembly  10 . Thus, the present invention contemplates multiple designs of the fins  52  about the clutch cover  12 . 
         [0046]    Other alternative processes obvious to those in the field of the art are considered to be included in this invention. This description is merely an example of an embodiment and limitations of the invention are not limited to the application. For instance, the exact shape and size of the clutch cover  12  may be varied according to the amount of space available and the type of engine used with the clutch cover  12 . Furthermore, the machines used to remove material from the clutch cover  12  may vary as well. A five axis laser cutter may be used to cut out the lever arm apertures in the clutch cover  12  body. A drill or other machine may be used to create the bolt holes or holes through the flange  42  and rim  44 . Finally, a leveling machine or other machine capable of leveling the device may be used to level the flange  42  relative to the rim  44 .