CA1119210A - Bowling pin and process therefor - Google Patents
Bowling pin and process thereforInfo
- Publication number
- CA1119210A CA1119210A CA000309023A CA309023A CA1119210A CA 1119210 A CA1119210 A CA 1119210A CA 000309023 A CA000309023 A CA 000309023A CA 309023 A CA309023 A CA 309023A CA 1119210 A CA1119210 A CA 1119210A
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- Prior art keywords
- belly
- main body
- bore
- shank
- core
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
ABSTRACT OF THE DISCLOSURE
A bowling pin is prepared by injection molding, a high impact polypropylene belly and, thereafter, in-serting into the belly a wood laminate core. The poly-propylene is utilized in the presence of a coupling agent and a blowing agent and is admixed with a filler. The products produced in accordance herewith are suitable replacements for existing wood bowling pins.
A bowling pin is prepared by injection molding, a high impact polypropylene belly and, thereafter, in-serting into the belly a wood laminate core. The poly-propylene is utilized in the presence of a coupling agent and a blowing agent and is admixed with a filler. The products produced in accordance herewith are suitable replacements for existing wood bowling pins.
Description
i~szio BACKGROUND OF THE INVENTION
___________________ ______ 1. FIELD OF THE INVENTION-The present invention pertains to bowling pins.
More particularly, the present invention pertains to com-positions and processes for manufacturing bowling pins.
Even more particularly, the present invention pertains to bowling pin structures, compositions and processes therefor.
___________________ ______ 1. FIELD OF THE INVENTION-The present invention pertains to bowling pins.
More particularly, the present invention pertains to com-positions and processes for manufacturing bowling pins.
Even more particularly, the present invention pertains to bowling pin structures, compositions and processes therefor.
2. PRIOR ART-In the sport of bowling there has been developeda plurality of synthetic resinous accoutrements including bowling balls, shoes, as well as dressings for the lanes, per se. Yet, the sport has consistently employed and utilized wooden bowling pins. Although there has been proposed heretofore bowling pins formed from synthetic resins, see, inter alia, U. S. Patent 3,268,636, such bowling pins have not encountered commercial utilization.
One of the major problems encountered with synthetic bowling pins as differentiated from wooden bowling pins, is strictly aesthetic. Synthetic bowling pins do not emit the same sound, upon ball impact, as do wooden pins. In essence, prior art synthetic bowling pins emit a muffled or mitted sound as compared to the resounding noise of wooden pins. This has greatly depre-ciated the utilization of synthetic bowling pins.
_~_ Another problem encountered with prior art synthetic bowling pins is durability. Oftentimes, the prior art synthetic pins could not reach or attain the impact strength and/or compressive strength of the hard maple used in conventional bowling pins.
The present invention, as will subsequently be detailed, provides a bowling pin formed from a synthetic resin, as well as wood, which overcomes all of the debi-litating factors of the prior art and which surpasses or equals the properties of wooden pins.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a bowling pin comprising (a) a synthetic resinous hollow outer shell and (b) a wooden laminate neck-carrying core. The core is dimensioned to be slightly larger than the interior opening or hollow of the shell or belly. The core is inserted by heating the shell to expand it and, then, inserting the core.
Thereafter, the assembly is permitted to cool to room temperature. Thus, the inner core is shrink-fitted into the shell.
The outer shell or belly is formed by injection molding a high impact polypropylene in admixture with a filler and in the presence of a coupling compound and a surfactant.
~; The products produced in accordance herewith are comparable to and in many instances surpass conventional : wooden pins.
One of the major problems encountered with synthetic bowling pins as differentiated from wooden bowling pins, is strictly aesthetic. Synthetic bowling pins do not emit the same sound, upon ball impact, as do wooden pins. In essence, prior art synthetic bowling pins emit a muffled or mitted sound as compared to the resounding noise of wooden pins. This has greatly depre-ciated the utilization of synthetic bowling pins.
_~_ Another problem encountered with prior art synthetic bowling pins is durability. Oftentimes, the prior art synthetic pins could not reach or attain the impact strength and/or compressive strength of the hard maple used in conventional bowling pins.
The present invention, as will subsequently be detailed, provides a bowling pin formed from a synthetic resin, as well as wood, which overcomes all of the debi-litating factors of the prior art and which surpasses or equals the properties of wooden pins.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a bowling pin comprising (a) a synthetic resinous hollow outer shell and (b) a wooden laminate neck-carrying core. The core is dimensioned to be slightly larger than the interior opening or hollow of the shell or belly. The core is inserted by heating the shell to expand it and, then, inserting the core.
Thereafter, the assembly is permitted to cool to room temperature. Thus, the inner core is shrink-fitted into the shell.
The outer shell or belly is formed by injection molding a high impact polypropylene in admixture with a filler and in the presence of a coupling compound and a surfactant.
~; The products produced in accordance herewith are comparable to and in many instances surpass conventional : wooden pins.
-3-For a more complete understanding of the present invention reference is made to the following detailed description and accompanying drawing. In the drawing, like reference characters refer to like parts throughout the several views, in which:
BRIEF DESCRIPTION OF THE DRAWING
_________ _____________________ FIG. 1 is a side elevational view, partly in phantom, of a bowling pin in accordance with the present invention;
FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. 1;
FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;
FIG. 4 is a sectional view tsken along the line 4-4 of FIG. 1, and FIG. 5 is a broken, cross-sectional view of an alternate embodiment of the head of the eore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, and with reference to the drawing and, in particular FIGS. 1-4, there is depicted therein a bowling pin or similar structure, generally denoted at 10, in accordance with the present invention. The pin 10 hereof, generally comprises an outer shell or belly 12 and an inner core 14.
With more particularity, the belly 12 comprises a substantially flat or planar base 16 and an arcuate or curvilinear sidewall 18. The belly has an open top. The belly has a hollow interior comprising a first diameter hollow or bore 20 which extends along a substantial por-tion of the vertical extent of the belly. The bore 20 terminates into and communicates with a reduced diameter bore 22. The bore 22 extends upwardly from the base 16.
The belly 12 has a annular recessed groove 24 formed in the base. A nylon ring 26 is emplaced in the groove in accordance with the requirements of the American Bowling Congress.
As will subsequently be detailed, the belly 12 is formed from a synthetic resinous material.
The core 14 hereof comprises an integrally formed cap portion 28, a neck portion 30, a main body portion 32 and a shank portion 34. The core 14 comprises a wood laminate of sections 36, 38, and 40 which are laminated together by any conventional method. The lami-nated cor,e has a unidirectional grain orientation which is continuous with the grain of the belly (not shown).
Preferably, a scanned, maple wood laminate having the unidirectional grain is utilized as the core 14.
The cap portion 28 and the neck portion 30 of the core are disposed exteriorly of the shell or belly 12 and conform to the conventional head and neck of a bowling pin. The neck portion 30 is configured to be continuous 9;2~0 with the upper edge 42 of the belly. In this manner no exterior discontinuities are presented.
The main body portion 32 of the core is disposed within the hollow 20 by shrink fitting, in a manner to be subsequently described. The portion 32 has a length less than that of the hollow 20, as shown, and a di~meter slightly larger than that of the hollow.
A plurality of circular grooves 44 are formed in the exterior of the main body portion 32. The grooves 32 have an adhesive emplaced therewithin for enhancing adhe-sion between the core and the interior of the belly. The grooves 44 are parallel and equidistantly spaced apart along the vertical extent of the main body portion.
Depending downwardly from the bottom surface of the main body portion is the shank portion 34 of the core The shank portion 34 has a diameter slightly larger than that of the bore 22 and is emplaced therewithin by shrink fitting. The shank portion 34, extends from the base 16 into the interior of the belly within the hollow 20.
Because the shank portion has a diameter less than that of the main body portion and has a portion thereof within the bore 20, there is, thus, defined an annular cavity 46 in the interior of the pin 10. The cavity 46 functions as a sound chamber for amplifying and reverberating the sound made upon impact with a ball. Furthermore, the cavity provides the proper balance to the pin.
3ZlO
Referring, again, to the drawing, the shank por-tion 34 has a plurality of grooves 48 circumferentially disposed therearound. The grooves 48 are formed on the exterior of the shank portion 34 which lies within the bore 22. The grooves 48 have an adhesive emplaced therewithin to promote adherence between the core and the belly in the manner heretofore described.
A clearly shown in FIGS. 1 and 2, the shank por-tion 34 has a vertical partial bore 50 formed therein.
The bore 50 is formed centrally in the shank portion and extends upwardly from the base of the shank into the interior thereof. The bore 50 receives the fingers of an automatic pin setting machine (not shown).
In fabricating the pin 10 hereof the exterior is provided with an outer coating of paint or plastic to protect the belly and core and which has the conventional stripings thereon.
Referring, now, to FIG. 5, there is depicted therein an alternate embodiment of the present invention, generally, denoted at 110. In accordance herewith the head 112 of the core 114 includes a recessed portion 116.
The recess 116 extends around the head and has an upper, substantially flat or planar surface 118. The lower ter-minus of the recess defines as annular seat or shoulder 120. A channel 122 is formed in the top surface 118 and depends downwardly therefrom into the interior of the head portion 112.
.
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A cap 124 is emplaced in the recess 116 and seats on the annular shoulder 120. The cap 124 has a width equal to the width of the recess such that the exterior wall thereof in contiguous with the exterior wall of the head portion 112 to avoid outer discontinuities. The top 126 of the cap has a spherical configuration to impart a bowling pin cap configuration to the assembly. The top of the cap 124 has a finger 128 which is shrink fitted into the channel 122 in the same manner as the core portions are shrink fitted into the bores of the belly.
The cap 124 is formed from the same synthetic resin as the belly to impart high impact and compressive strength to the head of the pin. As is known to the skilled artisan, it is either the head of the pin or the belly, but not the neck, which is most often subjected to impact and compression.
As hereinbefore noted, the belly and, where used, the cap, is formed from a synthetic resinous material. The material hereof consists essentially of (a) a high impact polypropylene and (b) a filler.
The propylene utilized herein is a high impact polypropylene, prepared by conventional techniques, and having a specific gravity of about 0.905. Generally, the polypropylene has an intrinsic viscosity ranging from about 2.3 to 3.7. Such polypropylenes are well known and commercially available, such as those sold by Hercules Chemicals under the codes 8623, 7523 and PC072.
Optimally, a blend of such Z~O
polypropylene are used herein, in any desired proportions.
These polypropylenes have intrinsic viscosities within the above-defined ranges.
The polypropylene is, generally, employed in an amount ranging from about seventy-five percent $o about eighty-five percent, by weight, based on the total weight of the material.
The other component in the synthetic resinous material is a filler. The filler, which must be com-patible~with the polypropylene and be susceptible to injection molding, generally, is employed in an amount ranging from about fifteen to about twenty-five percent, by weight, based on the total weight of the material.
The filler utilized herein is selected from the group consisting of silicon dioxide, asbestos fibers and mix-tures thereof. Where utilized as a mixture any desired proportions of the filler can be utilized.
The belly and/or cap is fabricated from the synthetic resinous material by the injection molding thereof. The molding of the material is, generally, carried out a temperature of from about 400-F to about 500 F. Preferably, the temperature ranges from about 425-F to about 475-F. In injection molding, the present material, a pressure of about eight thousand pounds per square inch (psi) is ordinarily employed.
The material is molded in the presence of a wetting agent and a blowing agent. The wetting agent and blowing agent are added separately to the material in a stepwise procedure.
szi Specifically, to the material is added, with agitation, the wetting agent, at room temperature and pressure. Thereafter, the blend is agitated for about five to ten minutes.
Next, the blowing agent is added to the blend, with agitation. The blowing agent is mixed into the blend for about five to ten minutes at room temperature and pressure to ensure a homogeneous mixture.
The resulting mixture is then plasticized in an extruder at the hereinbefore denoted elevated tem-peratures and pressures. From the extruder the mixture is then injected into a mold conforming to the desired configuration of the belly and/or cap.
The wetting agent utilized herein is, preferably, a synthetic fatty amide wax. More specifically, the wetting agent is, preferably, a fatty diamide synthetic wax. A particularly preferred type of wax is that sold by Glyco Chemicals, Inc. under the name ACRAWAX C, a trademark, which is utilized as a powdered wax. ACRAWAX C, a trademark, has the following reported physical properties:
Melting Point 140- to 145-C
Acid Value 8.5 max.
Gardner - 1963 5 max.
Flash Point 285 C
Specific Gravity ~ 25 C 0.95 to 0.97 Moisture Absorption 0.6% in 48 hours ~ 35 C and 100% RH
ASH Content Less than 0.5%
~92~0 As noted, this product is commercially available. Generally, the wetting agent is employed in an amount ranging from about 0.25 to 0.5 percent, by weight thereof, based on the weight of the polypropylene.
The blowing agent is utilized in an amount ranging from about one to ten percent, by weight, based on the total weight of the mixture. Preferably, the blowing agent is utilized in an amount ranging from about one to five percent, by wwight, based on the total weight of the mixture.
The blowing agent, per se, comprises an admix-ture of azodicarbonamide, butylated hydroxy toluene and calcium silicate. The butylated hydroxy toluene func-tions as a coupling compound and the calcium silicate functions to promote agglomeration of the filler and polypropylene.
The azodiacarbonamide is a commercially available product which, usually, is in admixture with a mihor amount of finely divided colloidal or f~me silica.
Such products are defined in British Patent No.
1,360,392.
The blowing agent admixture, preferably, compri-ses from about 89.75 to about 94.75 percent, by weight, of the azodicarbonamide; about 0.25 percent, by weight, of the butylated hydroxy toluene and from about five to ten percent, by weight, of the calcium silicate.
It should be noted with respect hereto that the blowing agent can be used in molding polypropylene, per se, and is not solely restricted to utilization herein.
' ~9Z10 In fabricating a bowling pin in accordance herewith, the belly and cap, if used, are injection molded by the procedure outlined above. Thereafter, the belly is heated to render expansible the interior thereof. Then, the main body portion and shank, having the adhesive in their grooves, are explaced in their respective bores such that the exterior of the neck por-tion of the core is contiguous with the exterior of the belly and the base of the shank is coplanar with the base of the belly. Finally, the assembly is permitted to cool to room temperature whereupon the belly portion contracts, thereby, shrink fitting the core into the interior bores by virtue of the appropriate core portions having a larger diameter than their associated bores.
Thereafter, the cap, if used, is fitted into the recess of the core head by the same procedure.
The bowling pins produced in accordance herewith and, as noted thereinabove, are comparable to or surpass the qualities of 100% wooden pins. To evidence this, a series of pins were prepared in accordance with the pre-sent invention. Thereafter, the pins were subjected to an American Bowling Congress type test and compared to conventional wooden bowling pins. The results of these comparisons were as follows:
~9~:10 TEST WOODEN PIN INVENTIVE PIN
Durability 5,000 bowling 15,000 to 18,000 games, max. bowling games Center of Gravity (Same for both types of pin) Radius of Gyration 13.2 to 14.8 14.2 Scleroscope 60 to 62 60 to 62 Weight 3 1/3 to 3~ lbs. 3 lbs. 5 oz.
Scoring 147 to 154 148.7 (average) Thus, the present pins are comparable in all physical respects to conventional wooden pins, but with much greater durability.
Having, thus, described the invention what is claimed is:
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BRIEF DESCRIPTION OF THE DRAWING
_________ _____________________ FIG. 1 is a side elevational view, partly in phantom, of a bowling pin in accordance with the present invention;
FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. 1;
FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;
FIG. 4 is a sectional view tsken along the line 4-4 of FIG. 1, and FIG. 5 is a broken, cross-sectional view of an alternate embodiment of the head of the eore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, and with reference to the drawing and, in particular FIGS. 1-4, there is depicted therein a bowling pin or similar structure, generally denoted at 10, in accordance with the present invention. The pin 10 hereof, generally comprises an outer shell or belly 12 and an inner core 14.
With more particularity, the belly 12 comprises a substantially flat or planar base 16 and an arcuate or curvilinear sidewall 18. The belly has an open top. The belly has a hollow interior comprising a first diameter hollow or bore 20 which extends along a substantial por-tion of the vertical extent of the belly. The bore 20 terminates into and communicates with a reduced diameter bore 22. The bore 22 extends upwardly from the base 16.
The belly 12 has a annular recessed groove 24 formed in the base. A nylon ring 26 is emplaced in the groove in accordance with the requirements of the American Bowling Congress.
As will subsequently be detailed, the belly 12 is formed from a synthetic resinous material.
The core 14 hereof comprises an integrally formed cap portion 28, a neck portion 30, a main body portion 32 and a shank portion 34. The core 14 comprises a wood laminate of sections 36, 38, and 40 which are laminated together by any conventional method. The lami-nated cor,e has a unidirectional grain orientation which is continuous with the grain of the belly (not shown).
Preferably, a scanned, maple wood laminate having the unidirectional grain is utilized as the core 14.
The cap portion 28 and the neck portion 30 of the core are disposed exteriorly of the shell or belly 12 and conform to the conventional head and neck of a bowling pin. The neck portion 30 is configured to be continuous 9;2~0 with the upper edge 42 of the belly. In this manner no exterior discontinuities are presented.
The main body portion 32 of the core is disposed within the hollow 20 by shrink fitting, in a manner to be subsequently described. The portion 32 has a length less than that of the hollow 20, as shown, and a di~meter slightly larger than that of the hollow.
A plurality of circular grooves 44 are formed in the exterior of the main body portion 32. The grooves 32 have an adhesive emplaced therewithin for enhancing adhe-sion between the core and the interior of the belly. The grooves 44 are parallel and equidistantly spaced apart along the vertical extent of the main body portion.
Depending downwardly from the bottom surface of the main body portion is the shank portion 34 of the core The shank portion 34 has a diameter slightly larger than that of the bore 22 and is emplaced therewithin by shrink fitting. The shank portion 34, extends from the base 16 into the interior of the belly within the hollow 20.
Because the shank portion has a diameter less than that of the main body portion and has a portion thereof within the bore 20, there is, thus, defined an annular cavity 46 in the interior of the pin 10. The cavity 46 functions as a sound chamber for amplifying and reverberating the sound made upon impact with a ball. Furthermore, the cavity provides the proper balance to the pin.
3ZlO
Referring, again, to the drawing, the shank por-tion 34 has a plurality of grooves 48 circumferentially disposed therearound. The grooves 48 are formed on the exterior of the shank portion 34 which lies within the bore 22. The grooves 48 have an adhesive emplaced therewithin to promote adherence between the core and the belly in the manner heretofore described.
A clearly shown in FIGS. 1 and 2, the shank por-tion 34 has a vertical partial bore 50 formed therein.
The bore 50 is formed centrally in the shank portion and extends upwardly from the base of the shank into the interior thereof. The bore 50 receives the fingers of an automatic pin setting machine (not shown).
In fabricating the pin 10 hereof the exterior is provided with an outer coating of paint or plastic to protect the belly and core and which has the conventional stripings thereon.
Referring, now, to FIG. 5, there is depicted therein an alternate embodiment of the present invention, generally, denoted at 110. In accordance herewith the head 112 of the core 114 includes a recessed portion 116.
The recess 116 extends around the head and has an upper, substantially flat or planar surface 118. The lower ter-minus of the recess defines as annular seat or shoulder 120. A channel 122 is formed in the top surface 118 and depends downwardly therefrom into the interior of the head portion 112.
.
~9z~o \
A cap 124 is emplaced in the recess 116 and seats on the annular shoulder 120. The cap 124 has a width equal to the width of the recess such that the exterior wall thereof in contiguous with the exterior wall of the head portion 112 to avoid outer discontinuities. The top 126 of the cap has a spherical configuration to impart a bowling pin cap configuration to the assembly. The top of the cap 124 has a finger 128 which is shrink fitted into the channel 122 in the same manner as the core portions are shrink fitted into the bores of the belly.
The cap 124 is formed from the same synthetic resin as the belly to impart high impact and compressive strength to the head of the pin. As is known to the skilled artisan, it is either the head of the pin or the belly, but not the neck, which is most often subjected to impact and compression.
As hereinbefore noted, the belly and, where used, the cap, is formed from a synthetic resinous material. The material hereof consists essentially of (a) a high impact polypropylene and (b) a filler.
The propylene utilized herein is a high impact polypropylene, prepared by conventional techniques, and having a specific gravity of about 0.905. Generally, the polypropylene has an intrinsic viscosity ranging from about 2.3 to 3.7. Such polypropylenes are well known and commercially available, such as those sold by Hercules Chemicals under the codes 8623, 7523 and PC072.
Optimally, a blend of such Z~O
polypropylene are used herein, in any desired proportions.
These polypropylenes have intrinsic viscosities within the above-defined ranges.
The polypropylene is, generally, employed in an amount ranging from about seventy-five percent $o about eighty-five percent, by weight, based on the total weight of the material.
The other component in the synthetic resinous material is a filler. The filler, which must be com-patible~with the polypropylene and be susceptible to injection molding, generally, is employed in an amount ranging from about fifteen to about twenty-five percent, by weight, based on the total weight of the material.
The filler utilized herein is selected from the group consisting of silicon dioxide, asbestos fibers and mix-tures thereof. Where utilized as a mixture any desired proportions of the filler can be utilized.
The belly and/or cap is fabricated from the synthetic resinous material by the injection molding thereof. The molding of the material is, generally, carried out a temperature of from about 400-F to about 500 F. Preferably, the temperature ranges from about 425-F to about 475-F. In injection molding, the present material, a pressure of about eight thousand pounds per square inch (psi) is ordinarily employed.
The material is molded in the presence of a wetting agent and a blowing agent. The wetting agent and blowing agent are added separately to the material in a stepwise procedure.
szi Specifically, to the material is added, with agitation, the wetting agent, at room temperature and pressure. Thereafter, the blend is agitated for about five to ten minutes.
Next, the blowing agent is added to the blend, with agitation. The blowing agent is mixed into the blend for about five to ten minutes at room temperature and pressure to ensure a homogeneous mixture.
The resulting mixture is then plasticized in an extruder at the hereinbefore denoted elevated tem-peratures and pressures. From the extruder the mixture is then injected into a mold conforming to the desired configuration of the belly and/or cap.
The wetting agent utilized herein is, preferably, a synthetic fatty amide wax. More specifically, the wetting agent is, preferably, a fatty diamide synthetic wax. A particularly preferred type of wax is that sold by Glyco Chemicals, Inc. under the name ACRAWAX C, a trademark, which is utilized as a powdered wax. ACRAWAX C, a trademark, has the following reported physical properties:
Melting Point 140- to 145-C
Acid Value 8.5 max.
Gardner - 1963 5 max.
Flash Point 285 C
Specific Gravity ~ 25 C 0.95 to 0.97 Moisture Absorption 0.6% in 48 hours ~ 35 C and 100% RH
ASH Content Less than 0.5%
~92~0 As noted, this product is commercially available. Generally, the wetting agent is employed in an amount ranging from about 0.25 to 0.5 percent, by weight thereof, based on the weight of the polypropylene.
The blowing agent is utilized in an amount ranging from about one to ten percent, by weight, based on the total weight of the mixture. Preferably, the blowing agent is utilized in an amount ranging from about one to five percent, by wwight, based on the total weight of the mixture.
The blowing agent, per se, comprises an admix-ture of azodicarbonamide, butylated hydroxy toluene and calcium silicate. The butylated hydroxy toluene func-tions as a coupling compound and the calcium silicate functions to promote agglomeration of the filler and polypropylene.
The azodiacarbonamide is a commercially available product which, usually, is in admixture with a mihor amount of finely divided colloidal or f~me silica.
Such products are defined in British Patent No.
1,360,392.
The blowing agent admixture, preferably, compri-ses from about 89.75 to about 94.75 percent, by weight, of the azodicarbonamide; about 0.25 percent, by weight, of the butylated hydroxy toluene and from about five to ten percent, by weight, of the calcium silicate.
It should be noted with respect hereto that the blowing agent can be used in molding polypropylene, per se, and is not solely restricted to utilization herein.
' ~9Z10 In fabricating a bowling pin in accordance herewith, the belly and cap, if used, are injection molded by the procedure outlined above. Thereafter, the belly is heated to render expansible the interior thereof. Then, the main body portion and shank, having the adhesive in their grooves, are explaced in their respective bores such that the exterior of the neck por-tion of the core is contiguous with the exterior of the belly and the base of the shank is coplanar with the base of the belly. Finally, the assembly is permitted to cool to room temperature whereupon the belly portion contracts, thereby, shrink fitting the core into the interior bores by virtue of the appropriate core portions having a larger diameter than their associated bores.
Thereafter, the cap, if used, is fitted into the recess of the core head by the same procedure.
The bowling pins produced in accordance herewith and, as noted thereinabove, are comparable to or surpass the qualities of 100% wooden pins. To evidence this, a series of pins were prepared in accordance with the pre-sent invention. Thereafter, the pins were subjected to an American Bowling Congress type test and compared to conventional wooden bowling pins. The results of these comparisons were as follows:
~9~:10 TEST WOODEN PIN INVENTIVE PIN
Durability 5,000 bowling 15,000 to 18,000 games, max. bowling games Center of Gravity (Same for both types of pin) Radius of Gyration 13.2 to 14.8 14.2 Scleroscope 60 to 62 60 to 62 Weight 3 1/3 to 3~ lbs. 3 lbs. 5 oz.
Scoring 147 to 154 148.7 (average) Thus, the present pins are comparable in all physical respects to conventional wooden pins, but with much greater durability.
Having, thus, described the invention what is claimed is:
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Claims (20)
1. A bowling pin, comprising:
(a) a synthetic resinous belly comprising an arcuate side wall, a planar bottom and an open top, the belly having a hollow interior, and (b) a solid wooden core comprising a head portion, a neck portion, a main body portion and the shank portion, the main body portion and the shank por-tion being disposed within the hollow interior, the neck portion and the head portion extending through the open top of the belly, the exterior wall of the neck portion being contiguous to the sidewall of the belly portion.
(a) a synthetic resinous belly comprising an arcuate side wall, a planar bottom and an open top, the belly having a hollow interior, and (b) a solid wooden core comprising a head portion, a neck portion, a main body portion and the shank portion, the main body portion and the shank por-tion being disposed within the hollow interior, the neck portion and the head portion extending through the open top of the belly, the exterior wall of the neck portion being contiguous to the sidewall of the belly portion.
2. The bowling pin of claim 1 wherein:
the main body portion and the shank are provided with peripheral grooves therearound, the grooves being adapted to receive an adhesive therewithin.
the main body portion and the shank are provided with peripheral grooves therearound, the grooves being adapted to receive an adhesive therewithin.
3. The howling pin of claim 1 wherein:
the hollow interior is defined by a first diameter bore extending downwardly from the open top and a second reduced diameter bore communicating with the first bore and extending downwardly therefrom to the bottom of the pin.
the hollow interior is defined by a first diameter bore extending downwardly from the open top and a second reduced diameter bore communicating with the first bore and extending downwardly therefrom to the bottom of the pin.
4. The bowling pin of claim 3 wherein:
the shank portion is disposed in the second bore and extends from the bottom of the belly into the first bore, and the volume of the first bore around the section of the shank portion extending thereinto defines an annu-lar cavity.
the shank portion is disposed in the second bore and extends from the bottom of the belly into the first bore, and the volume of the first bore around the section of the shank portion extending thereinto defines an annu-lar cavity.
5. The bowling pin of claim 4 wherein:
(a) the main body portion of the core has a diameter slightly larger than that of the first bore, and (b) the shank portion of the core has a diameter slightly greater than that of the second bore.
(a) the main body portion of the core has a diameter slightly larger than that of the first bore, and (b) the shank portion of the core has a diameter slightly greater than that of the second bore.
6. The bowling pin of claim 3 wherein:
the bottom of the pin has an annular recess formed therein, the recess being concentric with the first bore.
the bowling pin further comprising: a nylon ring disposed in the annular recess.
the bottom of the pin has an annular recess formed therein, the recess being concentric with the first bore.
the bowling pin further comprising: a nylon ring disposed in the annular recess.
7. The bowling pin of claim 1 wherein:
(a) the belly comprises an injected molded synthetic resinous material consisting essentially of:
(1) from about seventy-five to eighty-five percent, by weight, based on the total weight of the material, of as high impact polypropylene, and (2) from about fifteen to twenty-five percent, by weight, based on the total weight of the material, of a filler, and (b) the core comprises a wooden laminate.
(a) the belly comprises an injected molded synthetic resinous material consisting essentially of:
(1) from about seventy-five to eighty-five percent, by weight, based on the total weight of the material, of as high impact polypropylene, and (2) from about fifteen to twenty-five percent, by weight, based on the total weight of the material, of a filler, and (b) the core comprises a wooden laminate.
8. The bowling pin of claim 7 wherein:
the filler is selected from the group con-sisting of silicon dioxide, asbestos fibers and mixtures thereof.
the filler is selected from the group con-sisting of silicon dioxide, asbestos fibers and mixtures thereof.
9. The bowling pin of claim 7 which further comprises:
a cap fitted onto the head portion of the core, the cap being formed from the same material as the belly.
a cap fitted onto the head portion of the core, the cap being formed from the same material as the belly.
10. The bowling pin of claim 1 wherein:
the head portion of the core has a circum-ferential recess formed therearound, the head comprising a substantially flat upper surface having a downwardly directed partial bore formed centrally thereof, the bowling pin further comprising a cap fitted onto the head portion, the cap seating in the recess of the head, the cap comprising a finger which projects into the partial bore formed in the head portion.
the head portion of the core has a circum-ferential recess formed therearound, the head comprising a substantially flat upper surface having a downwardly directed partial bore formed centrally thereof, the bowling pin further comprising a cap fitted onto the head portion, the cap seating in the recess of the head, the cap comprising a finger which projects into the partial bore formed in the head portion.
11. A process for manufacturing a bowling pin, comprising:
(a) injection molding a belly having a hollow interior and an open top from a synthetic resi-nuous material, (b) forming a wooden laminate core comprising a head portion, a neck portion, a main body portion and a shank portion, the main body portion and the shank portion, the main body portion and the shank portion being adapted to be disposed within the hollow interior of the belly, the main body portion and the shank portion having a diameter slightly larger than that of the hollow interior, (c) heating the belly to render it expansible, (d) emplacing the main body portion and the shank portion in the hollow interior, and (e) cooling the assembly to room temperature to shrink fit the main body portion and shank portion in the interior of the belly.
(a) injection molding a belly having a hollow interior and an open top from a synthetic resi-nuous material, (b) forming a wooden laminate core comprising a head portion, a neck portion, a main body portion and a shank portion, the main body portion and the shank portion, the main body portion and the shank portion being adapted to be disposed within the hollow interior of the belly, the main body portion and the shank portion having a diameter slightly larger than that of the hollow interior, (c) heating the belly to render it expansible, (d) emplacing the main body portion and the shank portion in the hollow interior, and (e) cooling the assembly to room temperature to shrink fit the main body portion and shank portion in the interior of the belly.
12. The process of claim 11 wherein:
the synthetic resinous material consists essentially of:
(a) from about seventy-five to eighty-five percent, by weight, based on the total weight of material, of a high impact polypropylene, and (b) from about fifteen to twenty-five percent, by weight, based on the total weight of material, of a filler selected from the group consisting of silicon dioxide asbestos and mixtures thereof.
the synthetic resinous material consists essentially of:
(a) from about seventy-five to eighty-five percent, by weight, based on the total weight of material, of a high impact polypropylene, and (b) from about fifteen to twenty-five percent, by weight, based on the total weight of material, of a filler selected from the group consisting of silicon dioxide asbestos and mixtures thereof.
13. The process of claim 12 wherein the belly is injected molded in the presence of a wetting agent and a blowing agent.
14. The process of claim 12 wherein the wetting agent comprises a higher fatty diamide synthetic wax.
15. The process of claim 12 wherein the blowing agent consists essentially of:
(a azodicarbonamide (b) butylated hydroxy toluene, and (c) calcium silicate.
(a azodicarbonamide (b) butylated hydroxy toluene, and (c) calcium silicate.
16. The process of claim 15 which further comprises:
(a) from about 89.75 to about 94.75 percent, by weight, based on the weight of blowing agent, of the azodicarbonamide.
(a) from about 89.75 to about 94.75 percent, by weight, based on the weight of blowing agent, of the azodicarbonamide.
17. The process of claim 11 wherein the belly is injected molded at a temperature ranging from about 400°F
to about 500°F and at a pressure of about 8000 psi.
to about 500°F and at a pressure of about 8000 psi.
18. The process of claim 11 which further comprises:
(a) forming a plurality of grooves about the periphery of the main body portion and the shank portions, and (b) placing an adhesive in the grooves prior to emplacing the Fore in the hollow interior,
(a) forming a plurality of grooves about the periphery of the main body portion and the shank portions, and (b) placing an adhesive in the grooves prior to emplacing the Fore in the hollow interior,
19. The process of claim 11 which further comprises:
filling a cap onto the head portion of the core, the cap being formed from the same material as the belly.
filling a cap onto the head portion of the core, the cap being formed from the same material as the belly.
20. A bowling pin, comprising:
(a) a belly having a central bore extending therethrough, the belly being formed from an injection molded high impact polypropylene containing from about fifteen to twenty-five percent by weight of a filler selected from the group consisting of silicon dioxide, asbestos fibers and mixtures thereof, and (b) a core comprising a wooden laminate, and including a head portion, a neck portion, a main body portion and a shank portion, the head portion and neck portion defining the head and neck of the pin, respec-tively, the main body portion and shank portion being shrink fittedly disposed in the central bore of the belly.
(a) a belly having a central bore extending therethrough, the belly being formed from an injection molded high impact polypropylene containing from about fifteen to twenty-five percent by weight of a filler selected from the group consisting of silicon dioxide, asbestos fibers and mixtures thereof, and (b) a core comprising a wooden laminate, and including a head portion, a neck portion, a main body portion and a shank portion, the head portion and neck portion defining the head and neck of the pin, respec-tively, the main body portion and shank portion being shrink fittedly disposed in the central bore of the belly.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11728377A JPS5342945A (en) | 1976-09-26 | 1977-09-29 | Bowling pin and method of manufacturing the same |
| JP52-117283 | 1977-09-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1119210A true CA1119210A (en) | 1982-03-02 |
Family
ID=14707902
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000309023A Expired CA1119210A (en) | 1977-09-29 | 1978-08-09 | Bowling pin and process therefor |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1119210A (en) |
-
1978
- 1978-08-09 CA CA000309023A patent/CA1119210A/en not_active Expired
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| Date | Code | Title | Description |
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| MKEX | Expiry |