US 3729196 A
A baseball bat having a hollow metal casing formed from a tube by swaging to form a conventional bat-shaped casing with the barrel end rolled over to form an inturned lip to interlock with a grooved end plug. A handle grip covers the handle end of the casing, and the interior of the casing is filled with a sound-absorbing wadding. The interior of the handle end of the casing is reamed out to obtain a center of gravity at a desired point forward of the midpoint of the bat.
Claims available in
Description (OCR text may contain errors)
7 9,21 1 Apr. 24, 1973 METAL BAT  Inventor: Jesse H. Heald, Jr., Tullahoma,
 Assignee: Worth Bat Company, Inc., Tullahoma, Tenn.
 Filed: Oct. 1, 1970  Appl. No.: 77,199
 US. Cl. ..273/72 A [51 Int. Cl. ..'..A63b 59/06  Field of Search ..273/67, 68, 72 A, 273/80 R, 80 A, 80 B, 80 C, 81; 220/48, 59, 60, 67
 References Cited UNITED STATES PATENTS 2,100,307 11/1937 McMinn ..273/8O B 2,379,006 6/1945 Johnson ..273/72 2,818,057 12/1957 Meyer et a1. 273/73 F X 3,138,380 6/1964 Satchell et a1. ..273/82 A 3,595,577 7/1971 Hodge 273/80 C 1 3,479,030 11/1969 Merola ..273/72 2,061,145 11/1936 Duffy ..220/60 X 2,884,969 5/1959 Lay ..273/81 R 3,083,969 4/1963 Bills, Jr. ....273/8O B 1,499,128 6/1924 Shroyer, Jr. ....273/72 1,61 1,858 12/1926 Middlekaufi. ....273/72 2,066,962 1/1937 Cross ..273/80 B 3,232,616 2/1966 Conklin et a1. ..273/82 A FOREIGN PATENTS OR APPLICATIONS 1 1/1934 Great Britain ..273/l69 9/1952 Great Britain ..273/l69 Primary Examiner-Richard C. Pinkham Assistant Examiner-Richard J. Apley Att0rneyMason, Fenwick & Lawrence  ABSTRACT 5 Claims, 5 Drawing Figures Patented April 24, 1973 INYENTOR Jesse H. HEALD L ATTORNEY 8 METAL BAT BACKGROUND OF THE INVENTION This invention relates to improvements in Baseball Bats, and particularly to bats of the hollow metal type.
For some time, the advantages of a hollow metal baseball bat over the conventional solid wooden bat have been recognized. The metal bat is stronger, lighter in weight, and will neither break nor splinter when a ball is hit, nor does it have the disadvantage of opening grain when left exposed to weather.
Prior attempts to produce a hollow metal bat have .not met with complete success. Some have contained seams which are unsightly, some have had improper weight distribution, others have given off a hollow sound when a ball is struck, rather than the solid sound with which baseball fans are familiar, and still others have had problems in retaining closure plugs in the outer end of the tubular casing which forms the major portion of the bat.
In order to attain the required weight distribution for proper balance, weights have been mounted within the hollow center of the bat at various places, and, in one instance, the metal tube from which the bat is formed has been swaged to provide a conventional bat shape, and to so distribute the metal of the original tube wall as to obtain equal weight per unit length of the finished bat casing. Various structural devices have been placed within the metal casing in an attempt to counteract the hollowness of the sound produced by impact of the bat against a ball. Usually, a plug of some type has been employed to close the open outer end of the bat and give it a finished appearance, but the plug has had a tight fit within the bat and been fixed in place by adhesive. Centrifugal force applied during swing of the bat coupled with the impact with the ball have provided a force combination frequently sufficient to overcome the adhesive hold of the plug and its force fit within the tube and to eject the plug from the tube end.
SUMMARY OF THE INVENTION The general object of the present invention is to provide a hollow metal bat which will be free from the disadvantages set out above.
A more specific object of the invention is to provide a metal bat which has a finished wall thickness of fixed dimensions that the center of weight is positioned forward, that is toward the large outer end of the bat of the longitudinal center of the finished metal casing.
Another object is to provide a bat having weight distribution to provide proper balance, while maintaining adequate strength in the area of greatest stress under impact of the ball.
A further object is the provision of a hat of this type wherein the hollow bat body is filled with a fibrous material to deaden the hollow impact sound of the bat against a ball, while adding little to the overall weight of the bat.
It is also an object of the invention to provide an actual interlock between the open large end of the bat and a closure plug for that end to prevent accidental dislodgement of the plug during use.
Still another object is the provision of an improved closure plug for the outer end of a metal bat.
Other objects of the invention will become apparent from the following description of one practical embodi- 'ment thereof, when taken with the drawings which accompany, and form part of, this specification.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of the components of a metal baseball bat embodying the principles of the present invention;
FIG. 2 is a perspective view of the assembled bat;
FIG. 3 is a longitudinal section through the bat, taken on the line 33 of FIG. 2;
FIG. 4 is an enlarged sectional view through the large end of the bat and its closure plug, illustrating the interlocking of the two members, and is taken on the line 4-4 of FIG. 3; and
FIG. 5 is an enlarged section through the handle portion of the bat, and is taken on the line 5-5 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings, the hat 1 is composed of three principal elements, a hollow metal casing 2, an end closure plug 3 and a handle grip and end closure member 4. Plug 3 is inserted into the larger end of casing 2, and the handle grip is slipped over the smaller end of the casing to assemble the elements.
Metal casing 2 is preferably formed from an extruded aluminum tube of uniform diameter and uniform wall thickness throughout. The tube is swaged to reduce its diameter at one end, to form a bat body having outer barrel portion 5 with the diameter of the original tube, a tapering intermediate section 6, and a handle portion 7 of considerably less diameter than the original tube. This operation provides a bat body of approximately conventional bat shape.
As the tube is swaged to reduce the diameter, the walls of the member become thicker as the tube diameter becomes smaller. This produces a casing having a barrel of uniform diameter and uniform wall thickness, a tapering portion of progressively decreasing diameter toward the handle end and of progressively increasing wall thickness toward that end, and a handle of reduced uniform diameter and increased uniform wall thickness, with the wall thickness in the handle being greater than in any other part of the casing. This produces a casing which is of uniform weight per unit of length throughout.
In order to have proper balance, a bat should not have its center of gravity at its midpoint, but at a point located further toward the large, barrel portion. In order to achieve this outward shift of the center of gravity, the casing is bored, or reamed, in its handle end to reduce the wall thickness in that area. The resulting thinner wall section 8 of the handle does not affect the strength of the bat in use, for the area of greatest strain under impact with a ball is in the tapering area, or at the juncture of the tapering area and handle. The wall thickness in these areas is not disturbed. The precise location of the center of gravity of the casing can be precisely determined by the amount of handle wall thickness removed, the length of the bored out section in the handle, or both.
One further operation is performed upon the aluminum tube to complete the formation of the casing. This is the spinning over, or rolling over, of the outermost end of the barrel, as at 9, to form an inturned annular flange for interlock with the end plug 3, as will be described. The spinning of the tube end results in an inturned flange 9 having a wall thickness less than that of the original tube and, therefore, of less thickness than the wall of the'barrel portion 5 of the casing. The spun, or rolled over, flange 9 also serves as a reenforcing rim to greatly strengthen the casing end and prevent it from being dented in use.
End plug 3 is molded from rubber or a rubber-like material. ltis molded to form an upper body 10 and a depending annular skirt 11. The body has a convex end wall 12, to provide a smooth end closure wall for the bat, and the skirt of the wall tapers convergently from the body for ease of insertion into the open barrel end of the metal casing. The body of the plug is peripherally grooved, as at 13, to provide a locking seat for the lip, or flange, 9 on the casing end.
In assembling the plug with the casing, the skirt end of the plug is inserted into the open end of the barrel, the rubberous material of the plug being compressed to permit entry of the plug within the annular opening centrally of the barrel lip 9. When the plug has entered far enough into the barrel for groove 13 to reach the barrel end, the compression force on the plug will be released and the plug will expand, seating the lip within the groove and bringing that portion of the plug skirt adjacent the body into firm contact with the inner wall of the casing barrel. This firmly locks the plug within the barrel, and avoids the use of adhesive as a holding means. The groove 13 is so located within the plug body that the convex end of the plug is closely adjacent the barrel end to form a pleasing end closure, quite similar in contour to the end of the conventional wooden bat.
Handle grip 4 is also a molded member, and consists of a cylindrical sleeve 14 and an end knob 15. Sleeve 14 is of sufficient length to cover the handle portion 7 of the metal casing, and the closed knob end forms a closure for the handle end of the casing and provides a conventional handle end shape to the bat. The rubber,.
or rubber-like, material of the handle grip offers a surface for gripping which will enable a better hold to be maintained on the bat than would be the case if the grip were upon the smooth metal handle of the casing, and, at the same time, it absorbs some of the shock of impact of the bat with a ball. The sleeve portion of the grip will be small enough to fit tightly onto the casing handle portion so that it will not slip off in use. If necessary, adhesive may be used to retain the handle grip in place.
Prior to closing the ends of the casing, a wadding 16 is packed within the interior to absorb sound and shock. This may be any suitable material. A wadding of cellulose fibers has been found to be quite satisfactory for this purpose.
The metal bat of the present invention is capable of a variation in center of gravity location to suit different preferences, merely by varying the depth, or diameter, or both, of the bore 8 within the handle portion of the casing. The bat has an end plug which will not fly out in use, and the flange on the casing end which locks the end plug in place stiffens the casing end and prevents denting. At the same time, the bat will have requisite strength, it will not have the hollow impact sound of prior bats and it will be substantially shoclofree.
While in the above one practical embodiment of the invention has been disclosed, it will be understood that the details of construction shown and described are merely by way of example, and the invention may take other forms within the scope of the appended claims.
I claim: I
1. A metal ball bat comprising a hollow, tubular metal casing formed from a seamless tube, said bat having a barrel portion of a constant predetermined outer diameter, an intermediate section of progressively decreasing outer diameter tapering into a handle portion of reduced uniform outer diameter, said barrel portion having a uniform wall thickness throughout its length, said intermediate section having a progressively increasing wall thickness from its juncture at the barrel portion to its juncture at the handle portion, said handle portion having a part thereof of a wall thickness less than that of the wall thickness of said intermediate section at the juncture 'of said intermediate section and said handle portion, said part being of sufficiently reduced wall thickness and/or of sufficient length within said handle portion as to locate the center of gravity of said casing beyond the longitudinal center of said casing toward said barrel portion, means to close the end of the barrel portion of the casing, and means to close the handle portion end of said casing.
2. The hat of claim 1 wherein said means to close the end of the barrel portion of the casing comprises a plug in the end of the barrel.
3. A metal bat as claimed in claim 1 wherein, the means closing the handle portion end of the casing is a handle grip having a sleeve to fit over the handle portion of the casing.
4. A metal bat as claimed in claim 3 wherein, there is wadding filling the hollow interior of the casing.
5. A metal bat as claimed in claim 4 wherein, the wadding is of cellulosic fibers.