BACKGROUND OF THE INVENTION

The present invention relates to a collar and shaft assembly and the like, and in particular to a shaft with a snap on collar. This collar and shaft assembly can be used for a variety of purposes, including in metal forming dies.

Shafts with collars can be used for a variety of purposes. For example, they can be used to provide a positive stop between components with the collar acting as a shoulder to abut the surface of another component. One example of this is in metal forming dies. Metal forming dies, such as stamping dies and the like, are well-known in the art. Progressive metal forming dies are unique, very sophisticated mechanisms which have multiple stations or progressions that are aligned longitudinally and are designed to perform a specified operation at each station in a predetermined sequence to create a finished metal part. Progressive stamping dies are capable of forming complex metal parts at very high speeds, so as to minimize manufacturing costs.

Heretofore, the dies used in metal forming presses have typically been individually designed, one-of-a-kind assemblies for a particular part, with each of the various components being handcrafted and custom-mounted or fitted in an associated die set, which is in turn positioned in a stamping press. Not only are the punches and the other forming tools in the die set individually designed and constructed, but the other parts of the die set, such as stock lifters, guides, end caps and keepers, cam returns, etc., are also custom designed, and installed in the die set. Current die making processes require carefully machined, precision holes and recesses in the die set for mounting the individual components, such that the same are quite labor intensive and require substantial lead time to make, test, and set up in a stamping press. Consequently, such metal forming dies are very expensive to design, manufacture, and repair or modify.

It would be further advantageous to have a collar and shaft assembly that can be used in a die or other situation that requires a collar with a shoulder that can receive a large force without breaking or shearing the assembly. It would be also advantageous to have a collar and shoulder assembly that is easy to assemble but stays connected to the shaft over time.

SUMMARY OF THE INVENTION

One aspect of the present invention is a collar and shaft assembly. The collar and shaft assembly includes a shaft having a generally cylindrical shape with a first end portion, a second end portion, and a stepped groove. The collar and shaft assembly includes a collar having a generally cylindrical shape with a first end portion, a second end portion, and an aperture that extends through the collar with a first generally cylindrical inner sidewall, and a second generally tapered inner sidewall. A groove extends about the interior surface of the first generally cylindrical inner sidewall. The collar and shaft assembly also includes a retainer ring that is closely received and retained in the stepped groove in the shaft and the groove on the collar.

Yet another aspect of the present invention is a collar and shaft assembly that includes a shaft having a generally cylindrical shape, a first end portion, a second end portion, and a retainer ring groove on the exterior surface of the shaft. The collar and shaft assembly includes a collar having generally cylindrical shape with a first end portion, a second end portion, an aperture that extends through the collar, and a stepped groove extending circumferentially above the interior surface of the aperture in the collar. The collar and shaft assembly also includes a retainer ring closely received and retained in the stepped groove in the collar and in the retainer ring groove on the shaft.

Yet another aspect of the present invention is a method for making a collar and shaft assembly. The method includes forming a shaft with a first end portion, a second end portion, and a stepped groove extending circumferentially about an exterior surface of the shaft. The stepped groove includes a first portion with a first groove depth and a second portion with a second groove depth that is less than the first groove depth. The method includes forming a collar with a first end portion, a second end portion, and an aperture that extends through the collar having a first generally cylindrical inner sidewall, and a second generally tapered inner sidewall. The method includes providing a retainer ring to be closely received in the stepped groove. The method further includes advancing the collar over the shaft until the generally tapered portion of the collar engages and compresses the retainer ring into the first portion of the stepped groove and then further advancing the collar over the shaft until the retainer ring expands and is seated in between the second portion of the stepped groove on the shaft and the groove on the collar.

These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written description, claims, and appended drawings.

