US 2379006 A
Description (OCR text may contain errors)
June 26, 1945. T. L. JOHNSON v2,379,006
VGONSTRUC'I2|:0N OF STRIKING IMPLEMENTS Filed Aug. 30, 1943 I NVENroR;
THEopoR; -L JOHNSON Me' A, c z ATTORNEY Patented June 26, 1945 UNITED STATES PATENT OFFICE CONSTRUCTION F STRIKING IMPLEMENTS Theodore L. Johnson, St. Louis, Mo.
Application August 30, 1943, Serial No. 500,723
This invention relates to improvements in construction of striking implements, and more particularly to improved materials and an improved relation of elements going to make up various articles for manual usage in swinging or impact service.
Among the numerous applications may be noted baseball bats, cricket bats, .billiard cues, golf club shafts, handles for various manual implements and tools, and similar elongate articles. 'I'he foregoing list of possible usages of the present improvements is not intended as exhaustive, but merely to exemplify the manifold possibilities of utilization. However, for purposes of brevity the description will be conned to construction of a presently preferred form of baseball bat.
Various attempts have heretofore been made to manufacture baseball bats and the like, of composite construction. It is known, for example, to provide a bat with a core or the like of metal tubing for purposes of adding strength. It is known to employ a variety of materials in the construction of implements of this general nature. However, so far as advised, all of such earlier proposed constructions have failed of general adoption, for various reasons of inadequate balance, service characteristics, flexibility, appearance, diculty or high costs of manufacture, and other reasons. l
The one-piece baseball .bats formed of wood and in general usage in regulation baseball, are subject to a number of shortcomings, among which may be noted the eifects of wood grain, often resulting in zones of weakness in the bat, sometimes also affecting the balance of the implement, and alwayssubject to the uncertainties of hidden defects which frequently result in splitting or breakage. It is accordingly a major general ob- .lective of the invention to overcome each and all of the defects as now existing in conventional regulation baseball bats and like implements.
A further object of the present invention is to couple the advantages above noted, with facilities for adjusting the axial balance of the bat or other shaft, individually to the preference of the user, this being possible without the requirement of any special skill or tools for the purpose.
Yet another object of the invention is attained in a bat, shaft, or similar implement of substantially split-proof construction; one which is, for practical purposes, of homogeneous construction and sectional makeup, and which, being built up from and upon a core portion will notexhibit any of the usual weaknesses due to internal defects.
Yet another object of importance is'attainedin a construction of shaft for a sporting implement or manual tool, which, although of fabricated.
construction and great strength, nevertheless will approximate in finish, a surface which is close in appearance and reactive effect to these characteristics of natural wood, whereby, upon attaining general usage, the article will to a minimum extent if at all, disturb the accepted performance and appearance characteristics of the olderk one-piece wooden articles.
The foregoing and still further objects will more clearly appear from the following detailed description of a preferred construction of baseball bat, particularly when considered in connection with the accompanying drawing Fig. 1 is an elevation of a baseball bat constructed in accordance with present improvements, a fragmentary portion ofthe striking zone thereof being broken away to show in section certain features of internal arrangement;
Fig. 2 is a transverse sectional elevation er1-- larged to substantially full scale, this section bef ing taken along line 2 2 of Fig. 1, and
Fig. 3 is a longitudinal sectional view substantially on a full scale, of the outer end portion of a baseball batbuilt according to present improvements.
Although articles within the intended scope of the appended claims may be produced by a number of processes, or Aby variations in steps of the single example given, it is thought to conduce to a better understanding of the nature of the elements going to make up the selected structural example, and the relation of these elements, to suggest certain steps of a preferred method of building a baseball bat; accordingly, although the structure is stressed and claimed, description of structurev is hereinafter correlated, in a degree, with method steps. y f
Referring now by characters of reference to the drawing, it is greatly preferred, although not strictly essential, that the shaft-like body of the article be formed by winding its outer elements on a starting mandrel or core portion; this is indicated generally at I and extends by preference but not necessarily, through the full length of the bat or other shaft, and in order to facilitate production in case of a wound body structure, the tube l0 is reduced somewhat in diameter toward and through the handle portion of the bat, as indicated at Il. Y
The tube I0 is preferably formed of a relatively rigid metal stock, seamless in nature, and is prothereof, in
vided for a purpose to appear with internally threaded end portions indicated at I2 at the outer end, and at I3 at the handle end. Into each of these threaded portions fits a threaded plug I4 at the outer end, and a. similar closure I5 at the handle end. These closures may be transversely kerfed as at I6 (Fig. 3) or provided with spaced spanner sockets to facilitate insertion and removal as desired. Besides the function of tube I0 as a core portion or mandrel in formation and the shaft or bat, aswell as an axial reinforcement, the bore of the tube I0 may also readily serve the purpose of a receiver for balancing in.
serts. These may be of lead or other metal and are indicated generally at I1, being of any suitable or individually desired length and intervened by or cushioned endwise with inserts 20 of corkv or the like, the latter being alsoiof suitable or individually desired lengths and number.
It will now have become obvious that by varyingthe location of the balancing weight elements I1 in the bore of tube I0, and maintaining their selected position by the proper number and location of the cork elements, which like the weight elements rather snugly rit the bore, any desired individual balance ofitheibat may be attained. It is realized that, of itself, similar provisionsfor balancing elongate articles have heretofore been made, hence no claim is made for this feature apart from the present combination. Some balancing provision is, however, particularly desired for effecting complete individualization4 of the article.
Outwardly of the core identified with tube I0, the body of the shaft, bat or the like is built up by winding over and around the core, a series of relatively narrow strips of wood veneer,` each preferably of minimum thickness. While itwill now have appeared as obvious to wrap the individual strips of veneer 2| in a direction at a right angle totheaxis of l the tube I0, it is preferred as makingfor greater strength, and to eliminate completely any effects of grain in the veneer, to lay up the wound servings of veneer in a directionv somewhat biased to a normal relation, as will clearly appear from the dotted` lines demarking the outer turns or servings of the veneer, in Fig. l.
It is of course contemplated that the Wrapping of the individual servings will be effected by power equipment, and for this purpose, temporary journalling Vand supporting trunnions or-pins (not shown) may be threaded into each end of the tube I0, say into the threaded seats I2, throughA whichlthe core ID may be power-rotated andthe strips of veneer 2I fed to the rotating tube or mandrel, from suitable supply rolls thereof. Continuity of feed mayreadily and conveniently be maintained by securing together the finishing and beginning'ends of the veneer strip, as by a thermoplastic or other bonding material which may besimilar to that hereinafter referred to, and which may be utilized for this purpose either in the form of a liquid or a thin film. It may also be notedl as entirely feasible to derive the taper of the shaft, as in a baseball bat,by directing -a feedof relatively thinner strip veneer onto the handle portion of the implement, andthe relatively heavier gauge material onto the striking portion of the nishedarticle, whereby there results substantially or exactly, the desired taper, as well as initial balance and shaping of the article. v
Itis a further preferencein the construction of a baseball bat to provide for a feed,automatic or manual, of a supply of a preferably thermosetting synthetic resin such as frequently used in plywood practice, onto or between the adjacent surfaces of the continuously wound plies or layers of the bat. The thermo-setting material is fed at such a rate .and in suflicient amounts so as to provide intervening layers, between the adjacent wound strips of veneer, as indicated at 22, and in such further amounts and locations that the plastic will occupy, but not substantially extend from the spaces indicated at 23, edgewise vof the adjacent continuous strips.
It is als'o a preference in building up the body of the shaft, as described, from wound strips or layers of wood veneer, to leave the outer serving of veneer free of the plastic, at least free of any added plastic material, except in the very minute lines of edgewise juncture of the several strips, as in the zone 24 (Fig. 1) ,and possibly also excepting the end zones of the structure, as later described.
As a convenient expedient in starting the winding operation of the veneer stripl over themandrel I0, the latter may be provided with angularlyiand axiallyspaced slots, or with tongues or the like (not shown) of just a width to lreceive the start-v ing end` portions of the veneer strip. This or a similar provision is particularly advisable since it is a preference in winding the veneer `onto the mandrel or core I0, to maintain it under Yan appreciable tension, whereby to assure against wrinkling or warping effects, and to obviate any misshapement which might otherwise appear from ballooning portions in the startinglor intermediate layers as wound.
At the finish end of each servingof veneer strip, depending upon the thickness of. veneer employed, it may sometimes be advisable or desirable to feather or taper the marginf'of` the strip, and to secure `such strip byan' added localized coating of a thermosetting or other plastic. This requirement may, however, be obviated'by a winding practice such that the finishingends of the strips will fall within an outer end zone25, or in an end zone 26, the latter constituting as will appear, vpart of the handle portion of the bat. The foregoing suggestion is made vin view of a further preferencev of providing each of the end zones 25 and 25 with an overlayer of a plastic material similar to or at least chemically compatible with the bonding layer'221between 'the wrappings, servings orplies of the body or shaft.` These overlayers extend preferably fully about the circumference of each end of the implement, and as will now readily appear, serve each as a protecting and securing sleeve'over the finishing ends of the wound strip of veneer. The overlayer 25 will serve a further valuable purpose in that it covers over and assists in producing the desired conformity around the otherwise exposed ends of the veneer strips in this zone. The plastic overlayer 25 thus forms in eifect a protecting cap over the outer end of the bat.
At the inner or handled end of the implement, the overlay26 will serve similarly to the overlay 25, the several noted purposes, but in this zone a somewhat increased amountv of the plastic is added, particularly atthe extreme end of the bat,
4 so as to form the collar or knob-like protuberance 30 resembling that provided on conventional baseball bats.
As an optional, and in many respects equally preferable practice, 4in forming up the body of the shaft, the veneer strips 2I may consist not of plastic material. With this practice it may not be necessary to add in a separate operation, the resin or other plastic material to cement the several layers together. However, a thermo-setting plastic being preferred, it is a present preference after the veneer strips are wound as described about the tube l and the overlayers 25 and 26 built into place, to place the now formed but as yet uncompleted article in a suitable mold or otherwise to confine it under conditions of suitable temperature and pressure for effecting a setting of the plastic, either by polymerization as is contemplated in present production, or by evaporation of solvent or other effect according to nature of the plastic materialsemployed.
The described curing operation in a pressure mold, assuming a phenol-formaldehyde resin to be employed as a thermosetting plastic, may, for example, be carried out in a steam-heated hydraulic press at a temperature selected for optimum results, say in a range of 280-300 degrees F. and at a pressure. of 2100 lbs., ten to fifteen minutes press treatment being usually sufcient to cure the plastic intervening or impregnating the several strip layers 22, as well as that forming the overlays and 26. Upon removal from the press after completion of the cure, it will now appear that the article will consist of whatmay be considered essentially an integra1 or unitary article, all parts of which in comparable section are of close to uniform strength, free of internal defects, closely similar in appearance and weight, to conventional baseball bats for example, and susceptible with the balancing provisions mentioned, vof being custom-balanced to meet the individual desires of the user.
Complete individualizaticn of the bat or other article, as to contouring and balance may be effected by building the article somewhat oversize in any zone, or over its entire length if desired. The oversize portions may be reduced by sanding or otherwise abrading to result in any exact contour desired. This may be done with the aid of an article formerly used by the individual, or by a developed template or other pattern, in numerous ways`which will now readily suggest themselves.
It will now have become obvious that quite the same principles described in the construction of baseball bats may equally well and with marked advantage be utilized in manufacture of other shafts in swinging or striking implements; for example, there exists by virtue or" the present improvements a noteworthy facility for varying flexibility, as in a golf club shaft, by variation of nature, width, thickness and tension of initial application of the wound strips, as well as by variation of the bonding plastic materials. The same advantages prevail in the manufacture of numerous other manually utilized implements for various sporting and utilitarian purposes.
It will now have become obvious that the present improvements lead themselves to a wide variation in both choice and nature of materials to be utilized with and bonded by the selected plastic such as the thermosetting material described. It is in fact contemplated that, instead of distinct strips' of veneer, shaft elements may be formed up of strips or masses of other materials Wound on or otherwise applied to a starting core and bonded in position, possibly also with the final shape of the article determined and perfected by molding under pressure.
Although the invention has been described by making specic reference to a selected construction of baseball bat, the detail of description is to be understood solely in an instructive and not in any limiting sense,many variations being possible within the scope of the claims hereunto appended.
I claim as my invention:v f
1. A shaft for use as a striking implement or the like, formed of a plurality of spirally-arranged laminations of a wood veneer, layers of a plastic bonding material intervening at least certain of the laminations, and a cap of a similar plastic material, molded over a handle forming end of the implement, and projecting endwise beyond the wood veneer, the cap being enlarged to form an annular collar, and extending inwardly along the shaft suiliciently to icover and secure the end margin of the outermost serving of veneer.
2. In a striking implement for manual use, an elongate body including a tubular core and a plurality of laminations of wood arranged in wound relation over and about the core, a body of a polymerized plastic resin coextensive with each of said laminations and serving to bond the laminations into an integral or unitary structure, and a body of a similar resin at each end of the implement, molded on and bonded to the edges of the wound laminations otherwise exposed at the ends of the implement.
3. In a baseball bat or similar implement, an elongate tapered body consisting of a plurality of spirally wrapped wood laminations, layers of ther- ,mosetting synthetic resin adjacent each of and Vconstituting a bond between said layers, and a molded cap of the resin, overlying each end of the implement, one of said caps `constituting a securement for an end of the outermost lamination.
4. A baseball bat or the like, comprising a shaft built up at least in part of a convolute series of laminations of strip veneer impregnated with a resin, polymerized in the convolute laminations as laid up to form the shaft, the outer serving of veneer strip being continuous over the length of the shaft and terminating in the handle portion of the implement, and a collar and cap structure at the handle end of the shaft, overlying the end of the outer serving 4of strip, being molded to provide the collar, and formed of a resin comparable, in polymerizing characteristics, with that in the veneer laminations.
5. A shaft or body for use as a sporting implement or the like, the shaft being formed of laminations of veneer wound about the axis of the shaft and bonded by a setting plastic material, the shaft having certain portions covered by plastic overlays, which extend over otherwise exposed end portions of the veneer, the overlays being of rounded Icontouring in part, serving to conceal and protect the otherwise exposed edges of the veneer against spalling eifects.
6. A body or shaft for a striking implement or the like, constructed of strips of veneer wound in biased relation about the axis of the shaft, the outer end of the wound veneer strip being brought to lie in the region of a handle portion of the shaft or implement, and the latter provided with a resin overlay, in the region of and serving as a protection for said outer end of the veneer strip.
7. A baseball bat or similar implement of tapered section, formed of wound strips of wood veneer in wrapped relation about the longitudinal axis of the bat and including amounts of a thermosetting plastic material arranged to bond the faces and adjacent edge portions of the superposed wrapped strip portions of the veneer, the outer surface of the striking portion of the bat or the like, including a `core element, strip ma- 10 terialsoverlying Athe core element `in bias-.Wound relation thereto, and impregnated with a thermosetting'plas'tic polymerized in situ about the core and betweenlayers of the strip, and anend cap of the polymerized plastic, which with the wound strip and` adjacent plastid-determines and xes. .the configuration, shaping, and dimensions of the implement.
THEODORE 1L. JOHNSON.