Method Of Finishing Metal Ball-bat

Abstract

A metal ball-bat and method of finishing a tubular metal ball-bat at the large diameter end by securing a generally cylindrical resilient member within the end portion of the ball-bat. The resilient member is forceably inserted into the ball-bat end, and the end edge of the ball-bat deformed circumferentially inward to secure the resilient member within the bat. The resilient member also overlaps the end edge of the metal ball-bat as a safety feature.

Description

BACKGROUND OF THE INVENTION

The metal ball-bat has recently become a practical reality, and is described in detail in U.S. Pat. No. 3,479,030, owned by the assignee of the present invention. It has been the practice in finishing such tubular, metal ball-bats, to force fit a rubberous end plug into the large diameter open end of the ball-bat. This plug acts as a sound-deadening closure, as well as shielding the tubular open end of the metal ball-bat as a safety measure.

Metal ball-bats have been marketed with an end closure plug which is generally, cylindrical and has an annular groove formed therein. The end edge of the large diameter portion of the ball-bat is deformed inward and the end plug then forced into the open end so that the inwardly deformed edge of the ball-bat fits the groove provided in the end plug.

It is apparent that during use, the end plug of such metal ball-bats at the large diameter, striking end of the bat is subjected to significant force which tends to dislodge the end plug.

In order to satisfy the desires and needs of metal ball-bat users, a wide variety of ball-bats sizes and weights must be provided because such variations are readily available in wooden ball-bats. Thus, the metal bat maker must provide bat diameters ranging from about one and three-quarters to two and one-half inches, with gradiations of one-eighth inch being provided. The weight variations of the bat can be provided by changing the wall thickness of the metal tube used, or by varying the weight of the end plug. The metal bat maker is faced with the problem of providing an end closure for a range of bat dimensions and desired bat weight ranges. A significant expense would have to be incurred to provide separate molding dies for forming end plugs for this varity of bat sizes.

The inventory control problems involved in matching the end closure to the proper bat size are also bothersome.

SUMMARY OF THE INVENTION

The present invention obviates the problems discussed above and allows for the use of a minimum number of different diameter end plugs. In practicing the method of the present invention a generally cylindrical, rubberous member is formed, then forceably inserted into the large diameter, open end of a generally tubular metal ball-bat. The cylindrical, rubberous member projects out of the end of the ball-bat a small, predetermined distance. The end portion of the metal ball-bat is then deformed inward, forming an inwardly projecting circumferential lip which securely engages the cylindrical, rubberous member. The rubberous member thus overlaps the end of the ball-bat to shield the metal end preventing exposure of the metal end. The resulting metal ball-bat has a permanently secured end closure member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view partly in section showing the bat end closure spaced above the generally tubular large diameter end of a metal ball-bat before forceable insertion of the end closure into the ball-bat.

FIG. 2 is a side elevation view of an assembly for circumferentially deforming the end of the metal ball-bat, while the end closure is disposed within the bat end.

FIG. 3 is a view taken along line III--III in FIG. 2.

FIG. 4 is an enlarged view of one of the deforming rollers shown in FIGS. 2 and 3.

FIG. 5 is a view in section of the completed end portion of the metal ball-bat.

FIG. 6 is a side elevation view of a molded piece which is cut to predetermined length to form two end closures in practicing the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention can be best understood by reference to the drawings which facilitate explanation of the method of the present invention. In FIG. 1, the large diameter, tubular end portion 10 of a metal ball-bat is seen with a generally cylindrical resilient rubberous member 11 disposed thereabove. The resilient member 11 has a rounded top portion 12, and has a diameter which is slightly greater than the inside diameter of the end portion 10 of the ball-bat. The resilient member 11 is then forceably inserted into the end portion 10, with only rounded portion 12 projecting out of the bat end portion 10, as seen in FIG. 2. It has been found that rotation of ball-bat facilitates the forceable insertion of the resilient member 11.

The ball-bat is then restrained from movement by means 13. The end portion 10 of the ball-bat is shown in FIG. 2 restrained from axial or lateral movement by the supportive gripping means 13. In the embodiment shown in the drawings, the ball-bat is rigidly held in place by the gripping means 13, with movement of the deforming rollers along the axis of the ball-bat, or downward in FIG. 2, effecting the forming of the end portion 10 of the metal ball-bat. It should be apparent that the forming can also be carried out by movement of the ball-bat toward fixed deforming rollers. Relative movement of either the deforming rollers or the ball-bat toward each other can be used to effect the forming. An exemplary bat end deforming apparatus 14 is shown in FIG. 2, adapted to an electric drive motor 15 via drive belt 16. The deforming apparatus 14 comprises a rotatable shaft 17 which is adapted to be driven by the drive belt 16, a circular roller mounting plate 18 connected to the rotatable shaft 17. A plurality, here four, of symmetrically spaced deforming rollers 19 are rotatably connected to the mounting plate 18.

As is best seen in FIG. 3, the deforming rollers 19 are symmetrically spaced about the central axis of the shaft 17 and plate 18 so that the bat end portion 10 will fit within the rollers 19. In an enlarged view of one roller 19 in FIG. 4, a tapered roller surface 20 is provided about the lower exterior surface of the generally cylindrical roller 19. Each roller 19 is rotatably mounted to plate 18 via rod 21, retaining nuts 22, with a thrust bearing 23 disposed between the roller 19 and plate 18. Ball bearings, now shown, are disposed between the roller 19 and the rod 21.

The entire mounting plate 18 wwth rollers 19 depending therefrom is rotated while being moved relative to the bat end portion to force the bat end portion into contact with the tapered surface 20 of each independently rotatable roller 19.

The edge 24 of the bat end portion 10 is thus deformed inward forming an inwardly projecting circumferential lip which securely retains the resilient member 11 in place. The edge 24 of the bat end portion 10 is deformed inward a sufficient distance to be overlapped by the resilient end closure member 11, so that the metal edge 24 is not exposed to contact by the bat user. The bat end portion which is exposed to contact near the resilient member 11 has a smoothly curved radius which is safe and has a pleasing appearance.

In practicing the method of the present invention, it is possible to utilize a long, cylindrical extrusion rod of resilient material such as rubber which is then cut to predetermined length for use as the resilient end plug member 11. The predetermined lengths of rubberous end plug provide weight variation for the ball-bat.

It is also possible to form a molded resilient member 25, as seen in FIG. 6, having rounded end portions 26 provided at each end. The member 25 is of predetermined length, for example, about three to five inches. The member 25 can then be cut at any point along its length to form two rubberous end plug members of the same or of different length and weight. This simple expedient allows for easy variation of the weight of the resulting end member and of the final ball-bat formed therewith. The provision of molding rounded end portions 26 simplifies final assembly and the appearance of the final product.

The ball-bat which is produced by the method of the present invention thus has an end closure which is very securely engaged by the ball-bat end portion to prevent dislodgement of the end closure during use. The striking end portion of a ball-bat can be moving at speeds approximately one hundred miles per hour, and the ball can have a similar velocity. It can be readily appreciated that tremendous forces are acting upon the end closure tending to dislodge it during usage. The method and structure of the present invention allows for simplified, extremely economical construction, while providing a safe, secure ball-bat.

Claims

I claim:

1. The method of securely inserting a sound-deadening end closure member within the large diameter end of a generally tubular metal ball-bat, which method comprises:

a. forming a generally cylindrical, resilient member;

b. forceably inserting the resilient member into the large diameter end of the metal ball-bat, so that the resilient member projects out of the ball-bat end a small predetermined distance;

c. forming an inwardly projecting circumferential lip at the large diameter ball-bat end to securely engage the resilient member by;

i. rotating a mounting plate upon which are symmetrically disposed a plurality of independently rotatable forming rollers spaced to accept the large diameter ball-bat end between the forming rollers;

ii. moving the ball-bat relative to the forming rollers in the direction of the ball-bat longitudinal axis whereby the predeterminedly formed forming rollers deform the end portion of the ball-bat inward to securely engage the resilient end closure.

2. The method specified in claim 1, wherein a generally cylindrical resilient article with rounded end surfaces, is molded and cut along its length to provide two resilient members of predetermined length and weight for insertion into the ball-bat.

3. The method specified in claim 1, wherein the metal ball-bat is rotated during forceable insertion of the resilient member.