STAMPED CLUTCH POCKET PLATE, METHOD FOR MAKING THE POCKET PLATE, AND CLUTCH INCLUDING THE POCKET PLATE

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of United States provisional patent application Serial No. 60/873,143 filed on December 6, 2006, and this application also claims priority to application Serial No. 11/943,020 filed November 20, 2007 which hereby are incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to: a stamped clutch pocket plate; a method for making the pocket plate; and a one-way clutch including the pocket plate.

2. Background Art

One type of one-way clutches such as disclosed by United States patent 6,193,038 includes struts that are received within respective strut pockets in an annular pocket plate and spring biased outwardly toward an adjacent annular notch plate to permit relative rotation of the pocket plate and notch plate with respect to each other in one direction about a central axis while preventing rotation thereabout in the opposite direction. Such pocket plates are conventionally made from powdered metal to provide the required strut pockets for receiving the struts and associated biasing springs.

SUMMARY OF THE INVENTION

One object of the present invention is to provide an improved clutch pocket plate.

In carrying out the above object, the clutch pocket plate of the invention is stamped with a one-piece construction and includes an annular flange that extends radially with respect to a central axis and a sleeve that extends axially from the annular flange and has axial splines. Semi-pierced strut pockets are stamped in the annular flange spaced circumferentially from each other and extend axially while remaining integrally connected thereto with a unitary construction. Each strut pocket includes a stamped spring pocket having an inner extremity including a stamped hole.

As disclosed, the strut pockets have T shapes, and each T- shaped strut pocket includes a circumferentially extending stem and a branch that extends radially from the stem and opens in a radially outward direction. A groove extends adjacent each strut pocket.

A groove extends adjacent each strut pocket, and each strut pocket having a T shape including a circumferentially extending stem and a branch that extends radially from the stem and opens in a radial outward direction. Also, the spring pocket of each strut pocket has a round inwardly tapering shape.

The stamped one-piece clutch pocket plate as disclosed includes semi- pierced pads stamped in the annular flange extending axially therefrom in the same direction as the strut pockets. The strut pockets and the pads alternate with each other circumferentially about the annular flange, and each pad has a generally trapezoidal shape including curved inner and outer radial extremities and radially inwardly converging circumferential extremities.

Thus, the stamped one-piece clutch pocket plate as disclosed has a groove that extends adjacent each strut pocket, with each strut pocket having a T shape including a circumferentially extending stem and a branch that extends radially from the stem and opens in a radial outward direction, with each spring pocket of each clutch pocket having a round inwardly tapering shape, and with semi-pierced pads stamped in the annular flange extending axially therefrom in the

same direction as the strut pockets and spaced circumferentially about the annular flange in an alternating relationship with the strut pockets.

Another object of the present invention is to provide an improved method for making a one-way clutch pocket plate.

In carrying the immediately preceding object, the method for making a one-piece clutch pocket plate in accordance with the invention is performed by stamping a blank to include an annular flange that extends radially with respect to a central axis and to include a sleeve that extends axially from the annular flange and has axial splines. Holes are stamped through the annular flange spaced circumferentially around the central axis from each other. Spring pockets are stamped around the holes with depths that are less than the axial thickness of the annular flange along the central axis and the annular flange remains flat while the holes through the flange are decreased in size. Strut pockets are stamped in a semi- piercing manner around the spring pockets in the annular flange and project axially therefrom while remaining integrally connected thereto with a unitary construction.

As disclosed, the spring pockets are stamped with round inwardly tapering shapes and the strut pockets are stamped with T shapes. Also, the T-shaped strut pockets are each stamped to include a circumferentially extending stem and a branch that extends radially from the stem and opens in a radially outward direction, and the strut pockets are stamped with a groove extending adjacent each strut pocket.

Thus, the method as disclosed is performed by stamping a groove adjacent each strut pocket and with each strut pocket having a T shape including a circumferentially extending stem and a branch that extends radially from the stem and opens in a radially outward direction.

As disclosed, the annular flange is also stamped with semi-pierced pads that extend axially therefrom in the same direction as the pocket struts. Furthermore, the pads and pocket struts are stamped in a circumferentially

alternating relationship in the annular flange, and the pads are each stamped with a generally trapezoidal shape including curved inner and outer radial extremities and radially inwardly converging circumferential extremities.

Thus, the method for making a one-piece clutch pocket plate is performed by stamping a groove extending adjacent each strut pocket with each strut pocket having a T shape including a circumferentially extending stem and a branch that extends radially from the stem and opens in a radially outward direction, with the annular flange also stamped with semi-pierced pads that extend axially therefrom in the same direction as the strut pockets, and with the strut pockets and the pads stamped in a circumferentially alternating relationship with each other around the annular flange.

Another object of the present invention is to provide an improved one-way clutch.

In carrying out the immediately preceding object, the one-way clutch of the invention has a central axis and includes an annular notch plate that extends around the central axis and has notches spaced circumferentially about the central axis. A stamped one-piece clutch pocket plate of the clutch has an annular flange that opposes the spaced notches of the notch plate and extends radially with respect to the central axis. The pocket plate also has a sleeve that extends axially from the annular flange and has axial splines. Semi-pierced strut pockets of T shapes are stamped in the annular flange of the pocket plate spaced circumferentially from each other and extending axially while remaining integrally connected thereto with a unitary construction. Each strut pocket includes a stamped spring pocket having an inner extremity including a stamped hole. T-shaped struts are received within the strut pockets, and springs are received within the spring pockets and pivotally biasing the struts outwardly therefrom toward the notch plate to allow relative rotation between the notch plate and the pocket plate in one direction about the central axis but to prevent relative rotation therebetween in the other direction about the central axis.

The one-way clutch as disclosed has the annular flange of the pocket plate stamped with semi-pierced pads that extend axially therefrom in the same direction as the strut pockets and in a circumferentially alternating relationship.

The objects, features and advantages of the present invention are readily apparent from the following detailed description of the preferred embodiment when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is a half schematic view illustrating a one-way clutch that is constructed in accordance with the invention and includes an annular notch plate, a stamped one-piece clutch pocket plate, and struts biased by springs to cooperate between the notch plate and pocket plate to provide one-way clutching.

FIGURE 2 is a exploded perspective view of the one-way clutch of the invention.

FIGURE 3 is a perspective view illustrating the stamped clutch pocket plate from the opposite side shown in Figure 2.

FIGURE 4 is a partial view illustrating the manner in which struts of the clutch are received within strut pockets of the pocket plate and biased by a spring in an outward direction to provide the one-way clutching.

FIGURE 5 is a partial enlarged view of Figure 2 further illustrating the strut pockets of the pocket plate.

FIGURE 6 is a partial enlarged view of Figure 2 but cut away to better illustrate the manner in which the strut pockets and pads are stamped in a semi-piercing manner.

FIGURE 7 is a partial axial view of the pocket plate looking generally in the direction of Figure 2.

FIGURE 8 is a schematic view illustrating a stamping system for stamping the pocket plate.

FIGURE 9 is a partial sectional view illustrating the manner in which a pocket plate blank is initially stamped to provide a through hole that ultimately becomes part of the strut pocket.

FIGURE 10 is a partial view illustrating the manner in which a spring pocket is stamped in the blank about the through hole whose size is reduced by such stamping.

FIGURE 11 is a partial view illustrating a further stamping that provides semi-piercing of the strut pocket with the spring pocket.

FIGURE 12 is a view showing a further step where the pads are stamped in a semi-piercing manner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to Figures 1 and 2 of the drawings, a one-way clutch generally indicated by 20 includes a notch plate 22 and a stamped pocket plate 24 constructed in accordance with the present invention. Struts 26 received by the pocket plate 24 are biased by springs 28 toward notches 30 of the notch plate 22 to prevent relative rotation between the notch plate and the pocket plate in one direction about a central axis A of the clutch while permitting relative rotation therebetween in the opposite direction as is hereinafter more fully described. The stamped clutch plate 24 and the method for making the clutch plate as well as the clutch 20 will be described in an integrated manner to facilitate an understanding of all aspects of the invention.

As illustrated in Figure 1 , the clutch 20 includes a thrust plate 32 that slidably contacts the pocket plate 24 and is positioned by a snap ring 34 secured in a groove 36 of the notch plate 22 to maintain the assembled condition of the clutch. Assembly of the clutch in this manner is more fully described by allowed United States patent application Serial No. 11/201,482 filed on August 5, 2005 by Robert T. Fetting, Jr. and Gregory M. Eisengruber under the title of Overrunning Clutch Having Snap Ring Secured Thrust Plate, the entire disclosure of which is hereby incorporated by reference.

With reference to Figures 2-7, the pocket plate 24 has a stamped construction including an annular flange 38 that extends radially with respect to the central axis and a sleeve 40 that extends axially from the annular flange along the central axis A and has splines 42 utilized to provide rotational positioning with respect to the mechanism with which the clutch is utilized. It should be appreciated that the splines 42 may be formed in the sleeve 40 by stamping or by other processes such as radial impacting against a toothed mandrel or rolling on a toothed mandrel between toothed dies that are moved in opposite directions and form the sleeve to the mandrel shape at diametrically opposite locations.

Semi-pierced strut pockets 44 shown in Figures 2-7 are stamped in the annular flange 38 of the pocket plate 24 and spaced circumferentially from each other while extending axially along the central axis A and remaining integrally connected to the annular flange with a unitary construction. Each strut pocket 44 as best shown in Figures 5, 6, 7 and 12 includes a spring pocket 46 having an inner extremity including a stamped hole 48. Each strut pocket 44 also has a groove 49 extending adjacent thereto generally in an outline manner slightly spaced therefrom as is hereinafter more fully described.

As best illustrated in Figure 5, each strut pocket 44 has a generally T shape including a circumferentially extending stem 50 and a branch 52 that extends radially from the stem and opens in a radially outward direction at its outer end 54 while its inner end 56 is closed.

The spring pocket 46 of each strut pocket 44 receives an associated spring 28 as shown in Figures 2 and 4 and the associated strut 26 also has a somewhat T shape received within the T-shaped strut pocket and is biased by the spring 28 in an outward direction so as to cooperate with the notches 30 in the notch plate 22 shown in Figure 2 in order to permit relative rotation between the notch plate and the pocket plate in one direction while preventing such rotation in the other direction. Each spring pocket 46 as best shown in Figure 12 has an inwardly tapering shape that facilitates the receipt of the associated spring during assembly although this spring pocket can also be stamped without a taper, and the through hole 48 permits oil flow between the notch plate and the pocket plate to provide lubrication.

With reference to Figures 2, 3, 6 and 7, semi-pierced pads 58 are also stamped in the annular flange 38 of pocket plate 34 and extend axially therefrom in the same direction as the strut pockets 44. The semi-pierced pads 58 cooperate with the backsides of the strut pockets 44 so as to be slidably engaged by the thrust plate 32 (Figure 1) of the one-way clutch. As best shown in Figure 2, the strut pockets 44 and the pads 58 alternate with each other around the annular flange 38. Furthermore, as disclosed in Figure 7, each semi-pierced pad 58 has a generally trapezoidal shape including curved inner and outer extremities 60 and 62, respectively, and radially inwardly converging circumferential extremities 64. However, it should be appreciated that the pads 58 may have other shapes such as round, etc.

As illustrated in Figure 8, a stamping line 66 is of the transfer type including stamping stations 68 along which the pocket plate 24 is stamped through different operations. After each stamping cycle, the part being stamped is transferred to the next station after starting with a round blank. It should be appreciated that progressive stamping may also be utilized to provide the stamped pocket plate 24 from a strip that is moved along the stamping line from one end toward the other.

The construction of the semi-pierced strut pockets 44 and pads 58 shown in Figure 2 begins as shown in Figure 9 by initially stamping the annular flange 38 with the hole 48j through the part. Thereafter, the next stamping step as shown in Figure 10 stamps the tapered spring pocket 46 around the hole 48 while the annular flange remains flat with material movement that decreases the size of the hole to provide the final hole size. Thereafter, the strut pockets 44 are semi-pierced as shown in Figure 11 to the T shape previously described without stamping through the thickness of the annular flange. This stamping is performed with an outline perimeter die that forms the groove 49 adjacent the strut pocket 44 to permit the semi-piercing as shown while maintaining shape accuracy and squareness of the strut pocket walls. The pads 58 are then semi-pierced as shown in Figure 12 so as to extend axially from the annular flange 38 as previously described in an alternating relationship with the strut pockets 44.

The pocket plate 24 illustrated in Figure 2 has the axial flange 48 located at the radial inner extremity of the annular flange 38; however, in other embodiments the axial sleeve may be located at the radial outer extremity of the annular flange. Furthermore, the order in which the stamping progresses can be varied such as, for example, semi-piercing the pads 58 before the strut pockets 44 rather than after the strut pockets.

While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.