US3147974A - Synthetic bowling pins - Google Patents

Description

United States Patent ()fiice 3,147,074 Patented Sept. 8, 1964 3,147,974 SYNTHETIC BOWLING PINS Leandra W. Tomarkin, Spring Valley, N.Y., assignor, by mesne assignments, to American Machine & Foundry Company, a corporation of New Jersey No Drawing. Filed Nov. 12, 1959, Ser. No. 852,210 6 Claims. (Cl. 273-32) This invention relates to bowling pins, and more particularly, concerns pins formed of synthetic, non-cellulosic organic material.

Conventional bowling pins are formed of sound, hard maple, in a single piece or in laminated form. As the pins must meet rigid specifications, the wood must be well selected, properly seasoned, and otherwise be of high quality, to allow the same to be fabricated into commercially acceptable pins.

As bowling becomes progressively more popular, with ever increasing pin requirements; the limited supply of satisfactory maple for pin manufacture, has given rise to substantial problems in the industry.

Furthermore, wood pins have a rather limited useful life due to abrasion and indentation in use. The normal deterioration of wood pins has been aggravated by the common usage of mechanical pin spotters, which impose a further wear on the pins as they are handled by the mechanism. After a relatively short interval of use, wood pins must be discarded or rehabilitated. Rehabilitation usually comprises shaving the pin to remove abraded or indented surface portions, followed by the application of various surfacing compositions or lacquers.

The use of a coating composition on the pins makes the pin body non-homogeneous, particularly with a substantial difference in specific gravity as between the coating composition and the wood, leading to an impairment in the qualities of the rehabilitated pin. Thus, the pin may be somewhat unbalanced; it does not have the bounce of the original pin; it does not emit the same sound on impact by the ball, and otherwise constitutes a somewhat inferior product, as compared to the original, all wood pin.

While attempts have been made to manufacture bowling pins from non-cellulosic materials, such efforts have met with little success. This is due to the large number of diverse properties and characteristics which must be exhibited by the finished pin, to meet rigid specifications and the preferences of bowlers. Thus, the specific gravity of the material from which the pin is made must be rigidly held within the range of .70 to .60, preferably .60. Furthermore, the material must have high abrasion resistance and a degree of resiliency which avoids permanent indentations on the pin surface.

In addition, the pin must show the correct amount of bounce when hit and must produce a sound when struck by the ball which is quite similar with that associated with struck wood pins. Furthermore, the pin must be made of a material which can be held to strict tolerances in respect to dimensions, specific gravity, and resistance to effects of humidity and temperature changes during normal usage.

In accordance with the instant invention, it has been found that a synthetic elastomericvmaterial known as polyurethane, can be fabricated into the form of bowling pins which show the several properties and characteristics mandatory in a commercially acceptable bowling pin.

The polyurethane, which is an organic diisocyanate modified polyether or polyester, is molded into a rigid body taking the form of a bowling pin. The polyurethane composition is formulated in liquid form and is introduced into an appropriate mold in a precisely measured amount. The formulation is of the type which foams to produce a cellular structure; which structure is adapted to have a predetermined specific gravity. Furthermore, the cells of the resultant molded body are preferably of the sealed, non-communicating type. The cells may have an average diameter of from about 0.5 to about 1.5 mm.

The foaming of the polyurethane composition within the mold is induced by the use of additional diisocyanate and water in the formulation; or by the use of foaming agents added to the composition, such as the halogenated hydrocarbons known as Freon, or the like. In this manner, the extent and distribution of the cells may be carefully controlled, to produce a finished molded pin having the desired specific gravity of about .60.

The molds are precisely dimensioned to insure accurate dimensioning of the finished molded pin, in accordance with accepted specifications. The foamable polyurethane composition is homogeneous throughout, and may, if desired, include an inert, inorganic filler in finely powdered form which is uniformly distributed through the composition. The filler may include titanium dioxide, magnesium oxide, aluminum trisilicate, or the like, in amounts of from about 5% to about 15% by weight. The filler may impart a uniform, homogeneous color to the molded pin body.

The polyurethane composition is made up with the requisite catalysts and other ingredients necessary to produce a foamed end product of the rigid type. The composition is measured out for introduction into the molds, in amounts suificient to allow for the desired extent of foaming action.

It has been found that the resultant, molded rigid pin bodies are highly resistant to abrasion and wear incident to the impact of the balls and handling by the mechanical pin spotters. Furthermore, the novel pins show excellent bounce characteristics entirely analogous to those normally associated with wood pins. Also, the polyurethane bowling pins produce a sound on impact by the balls, which is quite similar to that encountered with wood pins.

The molded polyurethane bowling pins show uniform balance and response, despite wide changes in humidity and varying temperatures within the limit of normal usage. Also, the pins can be produced in large numbers with small variations in weight as between individual pins; thus making possible closer weight tolerances than is possible with the wood pins.

The molded pins are readily cleaned with various commercially available detergents or solvents, which are without effect on the material from which the pin is made. With selected fillers, the molded pin will have a uniform, integral color. Thus, titanium dioxide will impart a white color to the pins.

As various changes might be made in the embodiments of the invention herein disclosed without departing from the spirit thereof, it is understood that all matter herein set forth is illustrative and not limiting except as set forth in the appended claims.

Having thus disclosed my invention, I claim as new and desire to protect by Letters Patent:

1. A bowling pin consisting of a rigid, homogeneous body of polyurethane having a cellular structure, the cells in said body having a size of from about 0.05 to about 1.50 mm. in diameter, said body being elongated and comprising a base at one end for engaging a playing surface, and a portion between said base and the other end adapted to be struck by a ball rolling along such playing surface.

2. A bowling pin consisting of a rigid molded homogeneous body of polyurethane having a cellular structure, the cells of said structure being of substantially uniform size not exceeding about 1.5 mm. in diameter, said body being elongated and comprising a base at one end for engaging a playing surface, and a portion between said 3 base and the other end adapted to be struck by a ball rolling along such playing surface.

3. A bowling pin consisting of a rigid, homogeneous body of cellular polyurethane, said body being colored white by the inclusion in said body of finely powdered titanium dioxide in an amount not exceeding 15% by weight, said body being elongated and comprising a base at one end for engaging a playing surface, and a portion between said base and the other end adapted to be struck by a ball rolling along such playing surface.

4. A bowling pin consisting of a rigid body of polyurethane having a cellular structure, said body being elongated and comprising a base at one end for engaging a playing surface, and a portion between said base and the other end adapted to be struck by a ball rolling along such playing surface.

5. A bowling pin consisting of a rigid body of polyurethane having a cellular structure and wherein the cells of said body are sealed and in non-communicating 20 portion between said base and the other end adapted to be struck by a ball rolling along such playing surface.

6. A bowling pin consisting of a rigid body of a reaction product of a polyether and an organic diisocyanate, said body having a cellular structure, said body being elongated and comprising a base at one end for engaging a playing surface, and a portion between said base and the other end adapted to be struck by a ball rolling along such playing surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,866,774 Price Dec. 30, 1958 2,894,919 Simon et al. July 14, 1959 3,012,987 Ansul Dec. 12, 1961 3,015,132 Bunting Jan. 2, 1962 FOREIGN PATENTS 733,624 Great Britain July 13, 1955 OTHER REFERENCES Rubber World for March, 1955; pages 765-769 cited.

ERNEST W. SWIDER Aottesting Officer UNITED. STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 147,974 September S 1964 Leandro W Tomarkin It is hereby certified that error appears in the above numbered patent requiring correction and the,

t the said Letters Patent should read as corrected be1o* Column 2, line 5, for "O.5' read .05

Signed and sealed this 12th day of January 1965.,

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of 5 Patents

Claims (1)

1. 4. A BOWLING PIN CONSISTING OF A RIGID BODY OF POLYURETHANE HAVING A CELLULAR STRUCTURE, SAID BODY BEING ELONGATED AND COMPRISING A BASE AT ONE END FOR ENGAGING A PLAYING SURFACE, AND A PORTION BETWEEN SAID BASE AND THE OTHER END ADAPTED TO BE STRUCK BY A BALL ROLLING ALONG SUCH PLAYING SURFACE.