Abstract:
A clutch retaining device for use in a clutch collar and clutch assembly. The clutch retaining device includes multiple cover clips which extend downwardly from the cover and have a substantial L-shape. The clutch collar has corresponding cover clip notches which correspond to the cover clips of the clutch collar cover. The clutch collar assembly includes a first and second clutch collar cover. The entire assembly includes a series of drive springs and drive pins which are compressed in place by the first and second clutch collar covers. A method for assembling the clutch collar assembly is also included. The method includes the steps of inserting drive pins into drive springs into drive pin receptors, aligning cover clips of a clutch cover with cover clip notches on a clutch collar, and connecting the clutch cover to the clutch collar and thereby depressing the drive pins and the drive springs.

Description:
This application is a divisional application of Ser. No. 09/235,574, filed Jan. 22, 1999 now U.S. Pat. No. 6,039,162. 
    
    
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     This invention pertains to the art of methods and apparatus for clutches, and more particularly to methods and apparatuses for clutch collars, and even more particularly to methods and apparatuses for clutch collar covers. 
     II. Description of the Related Art 
     It is well known to provide clutches with a clutch collar mechanism, and to provide the clutch collar with a cover. The clutch collar cover maintains the drive pins in a disengaged position until needed. A known problem in the art relates to the assembly of the clutch collar cover. In the past, the covers have been fixedly attached to the clutch collar, usually by means of screws or bolls. It is desirable to provide a cover that simply clips on to the clutch collar for ease of production and assembly. 
     U.S. Pat. No. 5,560,461 to Loeffler discloses a transmission gear synchronizing apparatus including an internally splined, annular shiftable clutch collar mounted for co-axial movement with the drive shaft. The clutch collar in the Loeffler patent does not include a clutch collar cover. U.S. Pat. No. 5,607,037 to Yarnell et al discloses a transmission gear synchronizer apparatus including an annular shiftable clutch collar positioned between two friction races. The clutch collar is mounted for co-axial movement with respect to the friction races to enable engagement of the clutch collar with transmission gears. However, the clutch collar in the Yarnell patent does not include drive pins or a clutch collar cover. 
     One other known type of clutch retaining device is disclosed in U.S. Pat. No. 4,306,405 to Fleigler. Fleigler discloses biasing springs that are seated in recesses and held in by a lower wall of a shell. However, this shell, which acts as a clutch collar cover, is screwed or bolted in place. 
     Another known type of clutch retaining device is described in U.S. Pat. No. 4,838,011 to Bramstedt et al. Bramstedt et al disclose a series of annular rings and annular flanges that act as the clutch collar cover. However, as in the previous patent, the flange is secured to the outer face of a sheave by a series of bolts. 
     What is needed is a clutch collar cover that retains the drive pins in a disengaged position without having to be screwed or bolted in place. The removal of the screws and bolts from the process allows an easier production and assembly process. The difficulties inherent in the art are therefore overcome in a way that is simple and efficient while providing better and more advantageous overall results. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, a new and improved clutch retaining device includes a substantially flat base plate, the base plate containing two openings for receiving drive pins, and at least two cover clips. 
     In accordance with another aspect of the present invention, the clutch retaining device has a clutch cover, which includes multiple cover clips, which extend downwardly from the cover. 
     In accordance with yet another aspect of the current invention, the clutch retaining device includes the cover clips having an angle between the first and second cover clips, and the third and fourth cover clips, of less than 90°. And more preferably, the angle between the first and second clips, and the third and fourth clips, is 60°. 
     According to still another aspect of the current invention, the clutch retaining device has a clutch collar with multiple drive pin receptors, a top surface, a bottom surface, and multiple cover clip notches. The cover clip notches on the top surface are 90° out of alignment with respect to the cover clip notches on the bottom surface. 
     One advantage of the present invention is that the clutch cover holds the drive pins in place when disengaged. 
     Another advantage of the current invention is that the clutch cover is clipped into place on the clutch collar without the use of screws or bolts. 
     A further advantage of the current invention is that the cover clips are not aligned at right angles to each other, so that when the clutch cover is placed on the clutch collar, and rotated, the clutch cover remains securely attached to the clutch collar. 
     Still other benefits and advantages of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed specification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take physical form in certain parts and arrangement of parts. A preferred embodiment of these parts will be described in detail in the specification and illustrated in the accompanying drawings, which form a part of this disclosure and wherein: 
     FIG. 1 is a top view of the clutch assembly, showing the clutch collar in place between the first and second spur gears and the bevel gear; 
     FIG. 2 is a perspective view of the clutch collar assembly, showing the clutch collar, the first clutch collar cover, the splines, the first and second drive pins, and the first and second cover clips; 
     FIG. 3 is a cross-sectional view of the clutch collar assembly, showing the clutch collar, the first and second drive pins, the first and second drive springs, the first and second clutch collar covers, and the splines; 
     FIG. 4 is a top view of the clutch collar, showing the first, second, third, fourth, and fifth drive pin receptors, the first, second, third, and fourth cover clip notches, and the counterbores; 
     FIG. 5 is a top view of the first clutch collar cover, showing the first, second, third, and fourth cover clips; 
     FIG. 6 is a cross-sectional view of the clutch collar, showing the first, second, and fifth drive pin receptors, the counterbores, and the splines; and, 
     FIG. 7 is side view of the first clutch collar cover, showing the first, second, third, and fourth cover clips. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, which are for purposes of illustrating a preferred embodiment of the invention only, and not for purposes of limiting the same, FIG. 1 shows an inventive clutch collar assembly  60  as it is used in a clutch assembly  58 . FIG. 1 shows the clutch collar assembly  60  in place between a first spur gear  18 , a second spur gear  20 , and a bevel gear  24 . FIG. 1 also shows an endless chain  22 , a sprocket  26 , a crank shaft coupling  28 , and a drive shaft  16 . The assembly and operation of the clutch assembly  58  is well known in the art and will not be described herein. 
     With reference now to FIGS. 3-5, the clutch collar assembly  60  includes a clutch collar  10  and a pair of clutch collar covers  14 ,  15 . It should be noted that only one clutch collar cover is required with this invention. The clutch collar  10  can be of any type commonly known in the art. The clutch collar  10  shown has a shaft opening  46  that is preferably splined for operatively receiving a shaft such as drive shaft  16 . At least two annular projections  30  provide an annular groove  62  that operatively receives a shift fork (not shown). As is commonly known, the clutch collar  10  can be selectively moved along the axis of the drive shaft  16  by the shift fork (or other means) for operative engagement with other components. 
     With reference to FIGS. 2-6, the clutch collar  10  has at least one but preferably multiple pin receptors (four shown and referenced  38 ,  40 ,  42  and  44 ) that each receive a drive pin (two shown and referenced  12  and  13 ) and a drive spring (two shown and referenced  36 ,  37 ). As is commonly known in the art, each drive spring  36 ,  37  maintains a biasing force upon each drive pin  12 ,  13  so that the drive pins  12 ,  13  can be selectively inserted within holes (not shown) of an associated gear. In this way, the clutch collar  10  is connectable to an associated gear such as second spur gear  20 . The connectability of a clutch collar to a gear is well known in the art and thus will not be discussed in further detail. As best seen in FIG. 6, each pin receptor preferably has at least two counterbores forming a shoulder  48  within each pin receptor. Each drive pin  12 ,  13  has a generally cylindrical shape with an annular extension  64  at one end. Each drive pin  12 ,  13  is inserted within the corresponding pin receptor larger bore first. In this way, as shown in FIG. 3, the annular extension  64  contacts the shoulder  48  and is thereby prevented from extending only further into the smaller bore of the pin receptor. 
     With reference now to FIGS. 2-4, the clutch collar  10  has first and second ends  66 ,  68 . Each end  66 ,  68  has at least one but preferably multiple cover clip notches (four shown and referenced  50 ,  52 ,  54  and  56 ) for receiving later to be described cover clips from the clutch collar covers  14 ,  15 . It should be noted that the clip notches  50 ,  52 ,  54 ,  56  are only required on an end of a clutch collar  10  when a clutch collar cover  14 ,  15  will be connected thereon. When the clip notches  50 ,  52 ,  54 ,  56  are provided on both ends  66 ,  68 , as in the embodiment shown, the notches  50 ,  52 ,  54 ,  56  on one end are preferably offset from the notches on the other end. By offset it is meant that if one were to draw a perpendicular line (as shown by line  74  in FIG. 4) dividing the notches  50 ,  54  or, alternatively, notches  52 ,  56 , the two halves of the clutch collar  10  would not be mirror images. 
     And now with particular reference to FIGS. 3,  5 , and  7 , the clutch collar covers  14 ,  15  are used, as known in the art, to keep th, drive pins and drive springs within the pin receptors of the clutch collar  10 . Thus, as shown in FIG. 3, the clutch collar cover  15 , when connected to the first end  66  of the clutch collar  10 , contacts and supports one end of the springs  36 ,  37 . The other end of the springs  36 ,  37  contact and bias the drive pins  12 ,  13  toward the second end  68  of the clutch collar  10 . As noted above, the contact of the annular extension  64  against the shoulder  48  limits the extent to which the drive pins can extend through the pin receptors. As shown, each clutch collar cover  14 ,  15  has a shaft opening  70  for operatively receiving a shaft such as drive shaft  16 . The shaft opening  70  is coaxial with the shaft opening  46  of the clutch collar  10  when the collar cover is connected to the clutch collar  10 . Each clutch collar cover  14 ,  15  may also have one or more pin holes  72  for receiving drive pins not being supported by the cover. This will be explained. 
     With reference now to FIGS. 4,  5 , and  7 , each clutch collar cover  14 ,  15  has at least one but preferably multiple cover clips (four shown and referenced  32 ,  33 ,  34  and  35 ) that are received by the clip notches  50 ,  52 ,  54 ,  56  in the clutch collar  10 . In the preferred embodiment, the cover clips  32 ,  33 ,  34 ,  35  are substantially L-shaped and elastically deformable. By the term “elastically deformable” it is meant that the cover clips  32 ,  33 ,  34 ,  35  return to their original shape after being deformed. In other words, when the cover clips  32 ,  33 ,  34 ,  35  are “snapped” onto the clip notches  50 ,  52 ,  54 ,  56  of the clutch collar  10 , the clips  32 ,  33 ,  34 ,  35  are pushed radially outward, but then return to their original position as they are received by the notches  50 ,  52 ,  54 ,  56 . Preferably, first and second cover clips  32 ,  33  are aligned at an angle between 30° and 70° with respect to one another and the third and fourth cover clips  34 ,  35  are aligned at an angle between 30° and 70° with respect to each other. The first and fourth cover clips  32 ,  35  are aligned at an angle between 110° and 150° with respect to one another. Also, the second and third cover clips  33 ,  34  are aligned at an angle between 110° and 150° with respect to one another. Most preferably, first and second cover clips  32 ,  33  are aligned at a 60° angle with respect to one another and the third and fourth cover clips  34 ,  35  are aligned at a 60° angle with respect to each other. The first and fourth cover clips  32 ,  35  are aligned at a 120° angle with respect to one another. Also, the second and third cover clips  33 ,  34  are aligned at a 120° angle with respect to one another. The angles of the cover clips  32 ,  33 ,  34 ,  35  allow for the retention of the clutch cover  14 ,  15  on the clutch collar  10 . The angles are chosen so that when the clutch cover  14 ,  15  is rotated 90°, the cover  14 ,  15  remains attached to the clutch collar  10 . 
     Now with reference to FIGS. 2-6, the assembly of the clutch collar assembly  60  will now be described. First, the drive pin(s)  12 ,  13  is inserted into the larger bore of the appropriate pin receptor from the first end  66  of the clutch collar  10 . The corresponding drive spring(s)  36 ,  37  is then inserted into the same pin receptor. Next, the appropriate clutch collar cover  15  is placed over the first end  66  and is pressed against the drive spring(s)  36 ,  37  with the cover clips  32 ,  33 ,  34 ,  35  aligned with the cover clip notches  50 ,  52 ,  54 ,  56  on the clutch collar  10 . Once the cover  15  is snapped into place over the first end  66 , the cover  15  is then rotated relative to the clutch collar  10  such that the clips  32 ,  33 ,  34 ,  35  are no longer aligned with the notches  50 ,  52 ,  54 ,  56 . This secures the connection of the cover  15  to the first end  66  of the clutch collar  10 . When drive pins  12 ,  13  will be used from both ends  66 ,  68  of the clutch collar  10 , the cover  15  must be rotated such that the pin holes  72  in the cover  15  are aligned with the remaining (at this point empty) pin receptors. 
     With continuing reference to FIGS. 2-6, to add additional drive pins from the opposite end  68  of the clutch collar  10 , the drive pin(s) is inserted into the larger bore of the appropriate pin receptor from the second end  68  of the clutch collar  10 . The corresponding drive spring(s) is then inserted into the same pin receptor. Next, the appropriate clutch collar cover  14  is placed over the second end  68  and is pressed against the drive spring(s) with the cover clips aligned with the cover clip notches on the clutch collar  10 . In the preferred embodiment, once the cover  14  is on the clutch collar  10 , the L-shape of the cover clips fits around an annular extension  30  that forms either of the ends  66 ,  68 . Once the cover  14  is snapped into place over the second end  68 , the cover  14  is then rotated 90° relative to the clutch collar  10  such that the clips are no longer aligned with the notches. This secures the connection of the cover  14  to the second end  68  of the clutch collar  10 . The cover  14  can be rotated any amount so long as the cover clips are not aligned with the notches. The cover  14  must be rotated such that the pin holes  72  in the cover  14  are aligned with and receive the drive pins previously assembled and now extending from the second end  68  of the clutch collar  10 . 
     The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of the specification. It is intended by applicant to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.