US2752962A - Process for salvaging bowling pin billets - Google Patents

Description

July 3, 1956 A. J. GIESE 2,752,962

PROCESS FOR SALVAGING BOWLING PIN BILLETS Filed March 16, 1953 INVENTOR. d 66666 PROCESS FOR SALVAGIN G BOWLING PIN BILLETS Alphonse J. Giese, Fort Thomas, Ky., assignor to Vulcan Corporation, Portsmouth, Ohio, a corporation of Ohio Application March 16, 1953, Serial No. 342,530 r 1 Claim. (Cl. 144-309) The present invention relates to a process for salvaging bowling pin billets from which finished bowling pins are to be turned in a lathe.

Bowling pins are fashioned from blocks that have been cut from log wood in the green or undried state. These wood blocks are rough turned in lathes to somewhat the general contour of a bowling pin and such rough turned blocks are referred to in the trade, and hereinafter, as green billets. The rough turning operation often uncovered hidden defects in the blocks such as cracks, checks, fungus growths etc. which appeared on the surfaces of these particular green billets. All such billets have heretofore been considered unusable for making first grade bowling pins and were labeled green cull billets and were either discarded, or were dried, finish turned in a lathe, and then patched up for sale as second grade pins.

Further the drying and consequent shrinkage of a relatively thick mass of wood in a kiln, such as a green billet, or block simulating the shape of a bowling pin, is not uniform throughout the wood mass because the outer portion of the wood is exposed to the drying medium thereby becoming more thoroughly dry than the inner mass of the wood which is remote from, and is insulated to some extent by, the outer portion from the said medium. Greater and accelerated shrinkage of the outside mass of the wood with reference to the internal portion thereof creates a tremendous stress between the inside and the outside of the drying wood mass which causes many of the billets or blocks to check during the kiln drying step. In other words the surface mass of the wood around the widest portion of the billet was placed under great tension and the center mass was under an equally great compression.

By cutting these green blocks or billets into two half sections it was found that each half section was uniformly and thoroughly dried throughout its mass and that the drying time could be reduced to about half of the time required for drying whole billets or blocks. The most significant fact about the dried half sections was that the fiat face made by the saw cut became convex upon drying and that the convexity extended at its greatest height from between and A1 of an inch above the original face of the green block, thus indicating that the center mass of the wood had been relatively free and the outer sides of the section had shrunk without exerting a compressive force on the center of the section. The faces of the half sections could then be dressed down to a mating plane and then two half sections glued together to form a uniformly dried, composite billet free of internal stresses from which a bowling pin or other form could be turned in a lathe.

It is the principal object of this invention to salvage these green cull billets in an economical and practical manner and to produce therefrom first grade bowling pins which will meet the conditions of use as satisfactorily as pins made from clear, selected billets.

Another object of the invention is to provide a procnited States Patent ess of salvaging defective bowling pin billets which provides a substantial saving in kiln drying costs and also produces a finished, composite bowling pin which is uniformly dried throughout its body portion, thus materially decreasing its tendency to warp and split during use.

A further object of the invention is to provide a method which produces a more thoroughly and uniformly dried wood block or billet and also provides a saving of material by minimizing the occurrence of defective checks in the articles, caused during the drying process by unequal drying of different masses of relatively thick wood blocks.

These and other objects of the invention will become apparent to those versed in the art from the following description of my process taken in conjunction with the accompanying drawings which are illustrative of the invention.

In the drawings:

Fig. 1 is an elevational view of a green cull billet showing defects therein.

Fig. 2 is a top plan view of the billet shown in Fig. 1.

Fig. 3 is an elevational view of the clear green section cut from the billet depicted in Figs. 1 and 2.

Fig. 4 is an elevational view of the billet section taken from the right hand side of said section as it is shown in Fig. 3.

Fig. 5 is an elevation of a composite billet formed from two clear sections like the one shown in Figs. 3 and 4.

Fig. 6 is an elevation of a bowling pin turned from the composite billet shown in Fig. 5.

In carrying out the process of the present invention I start with a conventionally shaped green cull billet 10 that has been fashioned from a block of hard maple wood by rough turning said block in a lathe, oversize and to somewhat the same general contour of the usual bowling pin. As shown, the green cull billet is generally about seventeen (17) inches in length, is cylindrical in shape and has a narrow base portion 11, a relatively wide belly portion 12 about six (6) inches in diameter and a restricted neck portion 13 of about three (3) inches in diameter. The reference numeral 14 in Figs. 1 and 2 indicates a defect in the wood such as a crack, a check or a fungus growth which was uncovered when the green block was rough turned to form the green billet. These defective billets have been heretofore picked out and put aside from the clear billets as being inferior for the production of first class bowling pins and were frequently considered unusable for making any type of bowling pin. These defective billets 10 have been generally referred to in the art as green cull billets.

My process for salvaging the green cull billets 10 consists of initially passing a planar saw cut longitudinally through the center portion of each green cull billet, the plane of the out being indicated in Figs. 1 and 2 by the broken line 15. As shown in the drawings the planar saw cut is preferably passed through the longitudinal center line of the green cull billet to divide said billet into a clear half section 16 and an identically shaped half section 17 containing all the billet defects 14. It is also contemplated that the saw cut 15 may be passed through the central portion of the defective billet 13 offset on the side of the center line toward the defective portion, provided all saw cuts formed in a lot of green cull billets are directed through identically located center portions of said billets.

All the green cull billets have a more or less standard size after being rough turned in a lathe, and the passing of saw cuts through the same central portions of a particular lot of green cull billets produces a number of clear sections 16 each having a flat face 18 which will mate with the fiat faces on the other clear sections in the lot. The general contour of these flat mating faces 18 is illustrated in Fig. 4 of the drawings. The planar saw cut, represented by the broken line 15, should be directed through each of the-defective billets it either with the grain of the wood or in a plane normal to the grain of the Wood, it being thought that the utilization of these two alternate cuts will serve to localize all'the defects of the green cull billets to a discardablc section and produce a composite billet having the best characteristics in use.

The next step in my process is to load all the clear green sections 16 into a kiln to be therein treated in the conventional manner until they are thoroughly dried. It will be noted that only the clear green sections are placed in the kiln, that kiln will accon dat all. sections than whole billets and that dry nearly twice as fast as the whole billets and that therefore great savings in time and expense are effected by the initial step of cutting the defective unusable sections 17 from green cull billets 1t and then drying only their usable clear sections 16.

As will be appreciated from the foregoing specification Wood blocks of the thickness of the green bowling pin billets cannot be uniformly dried tiroughout their mass in a hill]. Generally the outside mass of wood in the block is first to dry and shrink and it then forms an insulation medium around the block which retards and sometimes prevents complete drying of the central mass of the blocks thus setting up great stresses in the block that causes checks. By utilizing my drying method checked blocks are eliminated and better uniformly dried composite pins are produced.

fter the clear sections 1.6 have been dried it will usually be found necessary to dress the mating faces 18 in a jointer to obtain well fitting pairs of clear half sec tions.

As shown in Fig. the dressed mating faces 13-18 on pairs of dried clear sections 16-16 are fixedly secured together to form a number of composite billets 19 comprising clear wood throughout. The pairs of clear sections are best united by applying glue to their mating faces, bringing the mating faces into aligned abutment and permitting the glue to dry whilst the sections are pressed together in face-to-face engagement in a suitable clamp. The composite billets K9 are then finsh turned in a lathe to form bowling pins 211 which will have a glue joint 21 between their half sections 22 and 23, the joints either extending in the general direction of the grains of the two pin sections or at right angles thereto. The latter mentioned wood grain condition is clearly illustrated in Fig. 6. The composite pins so made have the longevity of top grade, one-piece pins due to the fact that both half sections 22 and 23 are uniformly dried throughout and are clear of defects, whilst the glue joint 21 for the half sections extends longitudinally through the centers of the pins and thus utilizes the largest bonding surfaces possible for fixedly securing the sections together. By my process I can therefore obtain a composite bowling pin comparable in quality and performance to top grade, one-piece pins Whilst materially reducing manufacturing costs therefor particularly attributable to the fact that I cut green cull billets in two, discard the defective parts, and kiln dry only the usable clear parts.

What is claimed is:

In a process for salvaging defective bowling pin billets the steps of severing green defective billets into two sections by passing a planar saw cut through the longitudi nal center portions of said billets, said cuts being di rected thcrethrough to provide clear sections having fiat mating faces, discarding the sections containing the dcfccts, drying those green clear sections, dressing the mating faces of the dried clear sections, forming composite billets by fixedly securing together the dressed mating faces of pairs of clear sections, and turning bowling pins from the composite billets.

References Cited in the file of this patent UNITED STATES PATENTS Maly June 22, 19

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