Патент USA US3044787код для вставки
July 17, 1962 M. M. FRIEDMAN 3,044,777 BOWLING PIN Filed Oct. 19 , 1959 2 Sheets-Sheet 1 INVENTOR. M42” M ?ns-0 MA /v BY ’ 6 LA’ 9%‘ ATZ‘O/é/VZ/S July 17, 1962 M. M. FRIEDMAN 3,044,777 BOWLING PIN Filed Oct. 19, 1959 2 Sheets-Sheet 2 BY 6 ATTORNEYS , ice United States L " 1 2 (2) a similar set of pin leaves should be expected from a 3,044,777 ball which does not strike full in the pocket. The second attribute is that of sound. Although all the other problems may be solved, and the bowling alley Filed Oct. 19, 1959, Ser. No. 847,196 13 Claims. (Cl. 273-452) alleys, unless the sound is close in character and quality to the wooden pins, the patron will be slow to accept it. _With the foregoing résumé of the problem in mind, the objects of the present invention include: First, to provide ‘a plastic bowling pin which duplicates closely the observable characteristics of a maple bowling pin when in good condition, more particularly, to exhibit BOWLING PIN Mark M. Friedman, Inglewood, Cali?, assignor to Fiber mold Corporation, Torrance, Cali?, a corporation of California owners wish to install the all-plastic pins across their This invention relates to bowling pins, more particu larly to bowling pins molded of plastic material; and is a continuation-in-part of the copending application?led December 6, 1957, Serial No. 701,057, entitled “Bowl ing Pin.” 3,044,777 Patented ‘July 17, 1 962‘ ‘ a comparable action and scorability, and to produce a maple wood, or of maple wood coated with a thin coating 15 sound closely simulating the sound produced by maple bowling pins ‘when struck by the bowling ball and by each of thermoplastic material. The de?ciencies of the all wooden pins and the plastic-coated wooden pins are well known by informed people in the trade. In the ?rst place, the wood from which both types of other during pin action on the alley. Second, to provide a plastic bowling pin which is capa ble of withstanding impacts of a bowling ball and impacts from other bowling pins without splitting, cracking, or Bowling pins now in common use are either made of pins are made is a natural forest product with many chipping, and which, in ‘fact, remains in virtually its initial random variations in grain strength, depending on the conditions of climate and rainfall ailecting its growth. condition after many thousands of lines, that is, long be yond the life of a maple bowling pin even though the life In the second place, as a direct result of the ‘foregoing, of the maple bowling pin is prolonged by repeated recon ditioning and repair; thereby providing a bowling pin which, though having a higher initial cost than maple bowling pins, has instead such prolonged life that the net both types of pins have a relatively short useful life. Cracking along the grain, in the case of the all-wooden ‘pin, or delamination of the plastic coating, in the case of the plastic-coated pin, usually occurs ‘between 300 and 500 lines of play. The usual practice is to recondition these pins at least three or four times to prolong the life as long'as possible before discarding the pins entirely. cost per line to the bowling alley operator is materially reduced. Third, to provide a plastic bowling pin which utilizes a novelly constructed body member and bottom member of different Shore hardness to provide optimum resilience in The initial cost and the constant maintenance of these pins is an expensive “headache” to the bowling alley the region of ball-impact by the bowling ball, and opti proprietor. Furthermore, although his conscience may mum hardness and strength at the bottom of the bowling deplore it, he must continue to use pins far beyond their pin so that the stability of the bowling pin is not changed useful life. The patron or bowler is not usually aware of nor impaired with constant use. this because he is too far from the bowling pins to in spect them. Still, the bowler’s game is adversely affected whenever he bowls on wooden pins that have exceeded corporates a novel means of producing an essential musi Fourth, to provide a plastic bowling pin which in cal note closely simulating the ring of a wooden pin in good condition. Fifth, to provide a plastic bowling pin wherein the their relatively short useful life. In the third place, the entire problem is now seriously aggravated by a shortage of the proper maple woods used in bowling pins. The tremendous growth of the sport of bowling during the past decade along with the construc hibit the proper action typical of good quality wooden tion of new alley beds, now totalling over 75,000 individ pins. - ual alley beds throughout the United States, has over taken the slow natural process of maple-tree growth. The most logical answer to this problem is a com pletely synthetic pin, a pin constructed completely of center of gravity is located in the region corresponding to the center of gravity of a wooden pin, thereby to ex 45 With the above and other objects in view, as may ap pear hereinafter, reference is directedvto the accompany? ing drawings in which: ‘ FIGURE 1 is a top view of the bowling pin; FIGURE 2 is a longitudinal sectional view through 2——2 of FIGURE 1 showing one form of internal con synthetic material, such as plastic, that can be reproduced exactly the same, time‘ after time, a pin that does not de pend on conditions of climate or rainfall for its strength, struction; ' ‘ a pin that has no grain weaknesses subject to splitting, FIGURE 3 is a transverse sectional view through 3-3 and cracking, a pin that has no thin plastic ‘cover that of FIGURE 2»; may delaminate from the main body of the pin, a pin that FIGURE 4 is a sectional view through 4-4 of FIG will outlast wooden pins by thousands of lines with a low 55 URE 2;_ maintenance cost, resulting in a low net cost per line for FIGURE 5 is a longitudinal sectional view of a modi the bowling alley owner, a pin that will provide the patron with a consistent and unchanging pin for game after game. All these fundamental attributes are provided by an all-plastic pin of the proper design. But this alone is not enough. In order for the all-plastic pin to be accepted by the trade, two additional attributes must be provided. The ?rst of these is proper action or scorability. The history and tradition of the game of bowling requires that ?ed form of bowling pin; FIGURES 6, 7, 8, 9, and 10 are transverse sectional views thereof taken through 6——6, 7‘—7, 8—8‘, 9—9, and 10-40, respectively, of FIGURE 5; FIGURE 11 is a partial side, partial sectional view showing'a modi?ed form of the bottom member; FIGURE 12 is a transverse sectional ‘view through 12-12 of FIGURE 1l.' 0 ' ' ' there be no sudden changes in scoring conditions. Past 65 Reference is ?rst directed to FIGURES 1 through 4. records are constantly compared ‘with present results, and The bowling pin here illustrated includes a body mem it is essential that no fundamental changes occur that her 1 molded of plastic material. Externally, the body would alter these comparisons. This problem when an member is contoured to de?ne a belly 2, neck 3, and head alyzed and reduced to its essence can ‘be stated in this 4 of the bowling pin. The belly portion of ‘the body way: (1) a similar percentage of strikes should occur 70 member 1 is hollow Ito de?ne a cylindrical portion 5 and with a ball thrown in the pocket, slightly high up on the a conical portion 6, terminating in a rounded apex. pocket, or slightly thin to the right of the pocket; and Molded within the neck 3 and head 4 of the body mem 3,044,777 (3. Calcium stearate-14l grams. ber 1 is a reinforcing tube 7 formed of material having Titanium dioxide—l lb. and 272 grams. a greater strength than the material of the body member itself. The reinforcing tube 7 may be formed of metal, In the above formulation LT denotes a high elongation but is preferably formed of a high strength plastic mate low ?ow material whereas the numeral 1000 indicates in only the color of the Cycolac. Hycar 1411 is a butadiene rial. A bore 8 extends upwardly from the conical portion 6 acrylonitrile rubber in ?nely divided form and of high to a point approximately midway of the reinforcing tube acrylonitrile content. The Chlorowax 40 is a chlorinated 7. At this point the bore 8 forms a constricted portion para?in containing 40 percent combined chlorine. 9 which is closed by a small plug 10. Above the con As previously stated, the Cycolac is an ABS polymer stricted portion the bore 8 is enlarged to form a sound 10 whereas Hycar speci?ed above is a resin (copolymer) chamber 11 which extends to the upper end of ‘the head comprising acrylonitrile 35 %~50% and butadiene 65 % 4. The reinforcing tube 7 may also extend to the upper 50%. In the above example of the Hycar the acryloni end of the head or may terminate short of the upper end. trile is 42% and butadiene is 58%. The above example The bores 8 and 11 serve to center the pins during the has a Shore D hardness of 48, a speci?c gravity approxi molding of the body member to ensure concentric lo mately 1.01, and a tensile strength of approximately 1500 cation of the reinforcing tube 7. lbs/sq. in. The body member 1 receives a bottom member 12 also The above formulation has been particularly satisfac formed of plastic material. The bottom member is tory for the following reasons: molded to form externally an essentially flat base 13 and (1) The sound produced is closer to that produced a conical side portion 14 which diverge upwardly to‘ the by wooden pins than many other ‘formulations which were lower end of the belly 2 of the body member 1. The tried. conical side portion 14 terminates at a shoulder 15, and (2) The bounce approaches close to that of wooden the bottom member 12 continues to form a cylindrical pins. shell or reinforcing sleeve 16 which extends upwardly (3) The impact strength is excellent, and the body does into the cylindrical portion 5 of the body member I. not crack or chip like wood. Furthermore, it maintains The reinforcing sleeve 16 may be bonded to the cylindrical its original contour and dimensions so that throughout portion 5 of the body member 1 by a cement comprising the life of the pin the otiicial ABC dimensions can be essentially the plastic corresponding to the plastic from maintained. which the parts are molded and a solvent to obtain a As pointed out previously, the reinforcing tube 7 is chemical fusion or weld of that body member and bot also formed of plastic material and may be of Cycolac, that is, an ABS polymer, the formulation being such as tom member. 3 Preferably, however, an epoxy resin cement such as a to provide maximum strength. A particular formulation reaction product of bisphenol-A, and epichlorohydrin, 100 parts by weight, and a polymeric amine curing agent, of Cycolac having a Shore D hardness of 80, a speci?c 100 to 150 parts by weight, a ratio of 100 parts of the re 7500 lbs/sq. in. has been found to be satisfactory. In practice, the reinforcing tube is extruded or other gravity of approximately 1.06, ‘and tensile strength of action product and 115 parts of the curing agent, has been found particularly satisfactory, in that a bond is formed wise molded and then cast as an insert in the body mem ber 1. While a metal reinforcing tube 7, such as an which is actually stronger than the bottom member and body member. In either case, the cement 17 upwells 40 aluminum tube, is satisfactory as a reinforcing, the plastic ‘reinforcing tube offers the advantage of less density and above the reinforcing sleeve 16, as indicated in FIG therefore contributes to the lowering of the center of URE 2. gravity of the bowling pin. The bottom member 12 is solid to approximately the Reference is ‘directed to FIGURES 5 to 10. The bowl level of ‘the shoulder 15 except for a center hole or socket ing pin here illustrated is constructed of essentially the 18, in accordance with the standard for wooden pins of 45 same materials as that of the ?rst described bowling pin. the American Bowling Congress. The modi?ed bowling pin di?e-rs from the ?rst described While various plastic materials may be employed in structure in that a telescoping sleeve 19 is substituted for the construction of the bowling pin, Cycolac which is an the reinforcing sleeve 16. ABS copolymer, i.e., a resin comprising acrylonitrile l5%-35%, butadiene '20%—50%, and styrene 15%—65% 50 The telescoping sleeve 19 is relatively thin and is pro vided near its upper end with a small shoulder 20 which by weight has been found suitable. The letters “ABS” as serves to support a disk 21. In the construction here used above are merely the initials of the three constituents illustrated, the disk 21 is formed of Marine plywood and of the resin. This material has a tensile strength of 1500 has a central opening 21a. The disk serves to reinforce 7500 lbs/square inch; a Shore D hardness between 40 the sleeve 19 in the region of impact. 90; and an impact strength of 4-10 ft./ in. of Izod notch. Also in this construction, a central boss 22 is provided Tests have shown that a particular formulation, namely, from which extends a pair of diverging webs 23. The H2003 Cycolac is particularly satisfactory for the base. webs 23 form with the surrounding wall of the bottom This formulation has a Shore D hardness of 73, a speci?c member 12 a pocket in which is cast an eccentric mass gravity of 1.03, and a tensile strength of 5000 lbs/sq. in. The numerals 2003 constitute merely a color code indicat 60 24 which may be formed of plastic capable of bonding to the material of the base member and which may con ing a particular white whereas the letter “H” denotes a tain a ?ller or weighting material to increase its density. molding grade of the material. The purpose of the eccentric mass 24 is to introduce a The body member 1 is also formed of Cycolac or a predetermined unbalance to the bowling pin in keeping Cycolac-Hycar formulation. It is desirable, however, that the hardness of the body member be less than the bot tom member 12, for example, a Shore D hardness be tween 40-50 has been found satisfactory. A particular formulation which has been found satisfactory is as fol lows: Cycolac LT-—16 lbs. Cycolac Hl000-—16 lbs. Hycar 1411--7% lbs. Chlorowax 40-5 lbs. and 45 grams. Dioctyl sebacate-S lbs. and 45 grams. with the unbalance which is inherent in wooden bowling pins. For example, wooden bowling pins vary in ec centricity of their center of gravity between 0 and 100 gram-centimeters of torque. An eccentric mass is se lected which is within a comparable range. Reference is directed to FIGURES 11 and 12. In this 70 construction, a disk 25 formed of plastic is substituted for the plywood disk 21, and like the disk 21 serves to rein force the bowling pin in the region of impact. In this construction, webs 26 radiate in all directions from the K internal boss 22 to form a plurality of cavities. In order 3,044,777 5 to provide an eccentric mass, weight elements 27 may be placed in one or more of the cavities and held in place 6 same to the exact details of the constructions set forth, and it embraces such changes, modi?cations, and equivalents by a binder 28 of plastic material. ' of the parts and their formation and arrangement as come In each of the constructions illustrated, the cavity within the purview of the appended claims. formed by the body member 1 and bottom member 12 What is claimed is: functions as a sound-modifying chamber, and contributes l. A bowling pin formed of molded plastic material, to the production of a sound closely analogous to that comprising: a unitary molded body member de?ning ex of a wooden pin when the pin is struck. The sound ternally the belly, neck, and head of a bowling pin, and chamber 111, which is open to the upper end of the pin, having a generally cylindrical cavity extending upwardly is particularly effective to produce a ring closely anal 10 therein from its under end; and a unitary molded ‘bottom ogous to the characteristic ring of a maple wooden pin. member including a flat base and side walls completing the external contour of the bowling pin, and having a gen That is, this chamber or socket produces, when the bowl erally cylindrical tubular shell extending snugly into said ing pin is struck, a vibrating column of air similar to a Xylophone pipe. cavity with the generally cylindrical surfaces of said shell and cavity bonded together to de?ne a joint extending It has been ‘found that a particularly satisfactory musi longitudinally of said bowling pin. cal note is produced when the diameter of the sound 2. A bowling pin as set forth in claim 1, wherein: said chamber -11 is approximately 1” and its depth is approxi body member has a Shore D hardness of between; 40 and mately 3". Thus the sound produced by the open end 70 and said bottom member has a Shore D hardness of . sound chamber 11 and the sound produced by the larger closed sound chamber formed by the body member 1 20 between 55 and 90; said bottom member being appreciably harder than said body member. and bottom member 12 complement each other in pro 3. A bowling pin as set forth in claim 1, wherein: the ducing the rather complex sound inherent in a wooden head of said bowling pin is provided with a socket open P1I1, at its upper end and tending to produce a sound when said It should be noted that wooden bowling pins after a pre ' determined conditioning period, that is, after about 100 25 bowling pin is struck. 4. A bowling pin formed of molded plastic material, lines of play, become ?attened in this region, and when comprising: a unitary molded ‘body member de?ning ex- . so ?attened their scoring characteristics improve. The ternally the belly, neck, and head of a bowling pin, said plastic material found satisfactory in the construction of the present bowling pin does not deform permanently member having a longitudinal bore, including an enlarged pensate for the extra density of the plastic material so that the completed plastic bowling pin weighs the same as portion initially slidable snugly within the enlarged cavity a wooden or maple wooden pin, or within the American joint extending longitudinally of said bowling pin. in the manner of a wooden bowling pin; therefore, if 30 generally cylindrical cavity extending upwardly from the lower end of the body member; reinforcing means in the desired‘, a ?attened or cylindrical surface 29 may be in neck portion of said body member; a unitary molded itially provided in the region of impact of the bowling bottom member de?ning the base and side walls of the ball, as indicated in FJGURE ‘5. bowling pin complementary to said body member, said It should be observed that the accumulative volume bottom member including a generally cylindrical'tubular of the cavity within the bowling pin is calculated to com Bowling Congress weight limits (2 lbs.-, 14 oz. to 3 lbs. 10 in said body member; and an adhesive bonding said tubu lar portion to the walls of said enlarged cavity, to form a 5. A bowling pin as set‘for-th in claim 4, wherein: said body member has a Shore D hardness of between 40 and Partly by reason of the solid bottom member shown 70 and said bottom member has a Shore D hardness of in FIGURE 2, and the mass added to the constructions between 55 and 90; said bottom member being appreciably shown in FIGURES 5 land 11, and partly by control of harder than said body member. the densities of the body and base structures and by their 6. A bowling pin as set forth in claim 4, wherein: the wall thickness, vertical location of the center of gravity 45 head of said bowling pin is provided with a socket open is established within the range of the center of gravity in at its upper end and tending to produce a sound when said wooden bowling pins. bowling pin is struck. Tests have indicated that plastic bowling pins con 7. A bowling pin as set forth in claim 4, wherein: the structed in accordance with this invention not only per tubular portion of said bottom member is relatively thick form in a manner closely simulating a perfect wooden throughoutits length and reinforces the belly of said body bowling pin, but also have extremely long lives. A service member. life of 10,000 “lines” without repair appears feasible. This 8. A bowling pin as set forth in claim 4, wherein: the is in excess of four times the life of wooden pins that tubular portion of said bottom member is relatively thin have been carefully re?nished several times. and provided with a reinforcing disk at its inner portion in 02.). However, the plastic pins herein disclosed may also be 55 the plane of impact of a bowling ball against said body re?nished. This may be accomplished more readily than with wooden bowling pins. For example, if the base of a plastic bowling pin should become rounded, it is merely member. 9. A bowling pin as set forth in claim 4, wherein: said bottom member is provided with an eccentric mass. necessary to hold it vertically on a ?at surface heated to 10. A bowling pin as set forth in claim 4, wherein: said about 300° F. for 15 or 20 minutes and the base will 60 body member and bottom member de?ne internally a return to its initial flat condition. closed sound chamber in the region of the belly, and the If more elaborate treatment is desired, as for example to head of said body member forms an open sound chamber remove scratches, the base ends may be dipped in a solu extending into said head from the upper end thereof. tion of Cycolac and methylethy-l ketone, then baked to 11. A bowling pin, comprising: an upper unitary mem remove the solvent. A solution of 20% Cycolac and 80% 65 ber and a lower unitary member, each molded of plastic methyl ethyl ketone and a baking period of approximately material having a speci?c gravity greater than wood; one three hours at 150° to 180° F. has been found satisfactory. of said members having a generally cylindrical socket in The base end can then be machined to its initial measure one end and a stop rim bordering said socket and de?ning .ments. The base end of the plastic bowling‘ pin is with a plane at right angles to the axis of said member; the either treatment fully as good as a new pin, which is not 70 other of said members having a generally cylindrical shell the case with the re?nishing of a wooden pin. Still fur ther, the entire plastic bowling pin may be similarly dipped after several thousand lines. While particular embodiments of this invention have dimensioned to ‘?t snugly in said socket and having a shoulder abutting said rim, the generally cylindrical socket ‘and shell of said ‘members being bonded, each to the other, ' to de?ne a generally cylindrical joint extending longitudi been shown and described, it is not intended to limit the 75 nally of the pin; the cylindrical shell of said other member 3,044,777 7 also having a socket confronting and communicating with the socket of the ?rst member to form therewith a sound chamber, the volume and location of said sound chamber being such that said members when joined form a bowling pin having a weight and center of gravity corresponding to that of a wooden bowling pin. 12. A bowling pin formed of molded plastic material having a density greater than Wood, comprising: a unitary 8 sioned that said members form a bowling pin having the weight and center of gravity of a wooden bowling pin. 13. A bowling pin as set forth in claim 12, which also comprises: a reinforcing core of plastic material, having greater strength than said body member, molded within and bonded to the head vand neck portions thereof. References Cited in the ?le of this patent molded body member de?ning externally the head, neck, UNITED STATES PATENTS and belly of the bowling pin and extending to a level sub 10 stantially below the plane of engagement by a bowling ball to include that portion of the bowling pin 'below said plane 1,088,312 1,257,377 most subject to blows, said body member having a gen 1,583,824 Bishop ______________ __ May 11, 1926 erally cylindrical cavity extending upwardly therein from 1,603,880 2,166,950 2,775,456 2,797,923 Smith ________________ __ Oct. 19, German et a1. ________ _.. July 25, Schroeder et al. ______ __ Dec. 25, Dettman ____________ __ July 2, its under end to a level above said plane; a unitary molded 15 bottom member of greater hardness than said body mem ber including a ?at base and side walls completing the Whelan _____________ __ Feb. 24, 1914 Miller ______________ __ Feb. 26, 1918 1926 1939 1956 1957 external contour of the bowling pin, said bottom member OTHER REFERENCES having a generally cylindrical tubular shell extending snug Modern Plastics Encyclopedia, 1949, pages 104 and 107 ly into said cavity, the generally cylindrical walls of said 20 cited. shell and cavity being bonded together to form a longi Modern Plastics for September 1955; pages 104-108 tudinally extended joint; said body and ‘bottom members forming internally a closed chamber so located and dimen and 225-228 cited.