US3169020A

US3169020A - Bowling pin

Info

Publication number: US3169020A
Application number: US50012A
Authority: US
Inventors: Richard A Smith
Original assignee: AMF Inc
Current assignee: AMF Inc
Priority date: 1960-08-16
Filing date: 1960-08-16
Publication date: 1965-02-09
Anticipated expiration: 1982-02-09

Description

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Feb. 9, 1965 Fig. 5

IN V EN TOR. R/CHARD A. SM/ H ATTORNEY 3,169,020 BOWULNG PllN Richard A. Smith, Cornwall on the Hudson, NX., .assigner to American Machine it Foundry Company, a corporation of New .lersey Filed Aug. i6, 196th Ser. No. 50,012 6 Claims. (Ci. Z73-82) This invention relates to bowling pins and more particularly, to a novel base of excellent durability for bowling pins. A bowling pin in normal usage is subjected to severe destructive abuse from the battering of balls and other pins. One of the most pronounced areas of damage to the pin due to the striking of one pin against another and against the bowling alley, and from being hit by the ball, is the butt end, especially the corner portion of the pin base which forms the juncture between the side and bottom faces. As a consequence, most commercial pins are now equipped with a wear resisting base of tough plastic or other durable composition. Many of the base arrangements employed comprise an annular piece which encircles a central projecting shank portion of the pin and is secured by various means such as screws, adhesives and/or some locking arrangement.

The shortcomings of base fittings of the prior art often reside in the cumbersome procedure needed to aiiix the base or in the difiiculty of producing a practical arrangement which effectively resists separation of the base piece from the butt of the pin. Known prior means for securing wear resistant attachable bases have not been entirely satisfactory. Screws for example require considerable time to affix to the base. Adhesives for securing base pieces, if compatible initially with both the pin butt composition and the base insert, have not proven satisfactory in use largely due to dimensional changes, eg. evaporation of residual moisture from the wood, compression of the wood which severs the bond etc. Adhesive bonds moreover require relatively long periods to apply; are undesirable to use; require process-delaying drying periods and oftentimes employ adhesive compositions that are damaging to the plastic finish of the bowling pin. The present invention seeks to obviate these and other objections of the prior art and to provide an inexpensive irnproved readily afxed two-piece press-fitted base for bowling pins.

The present invention utilizes a two-piece base comprising an inner cylindrical sleeve containing an upper fiexible integral section which is easilyv fitted into the undercut of the pin butt and a main base piece pressfitted into cooperating relationship therewith. When the inner cylinder is inserted in the undercut of the pin followed by press-fitting the base piece in abutting relationship, the flexible upper extremity of the inner cylinder is radially deflected bythe collar of the main base member and seats itself inwardly in a circumferential locking groove in a manner securely holding both base members in the pin undercut against removal from the butt of the pm.

It is an object of the present invention to provide an easily affixed press-fitted bowling pin base of excellent durability.

it is a further object to provide an inexpensive pin base of relative simplicity of construction and of exceptional dependability against separation from the bowling pin.

Another object of the invention is to provide a pin base which is securely maintained in the pin undercut but which may be replaced when worn. Additional features and advantages of the invention will become apparent from the detailed description provided hereinafter.

In the accompanying drawings:

FIG. l is a cross sectional view of the lower portion of a bowling pin showing the preferred arrangement of the two-piece base of the invention secured in position therein.

FlG. 2 is a cross sectional View illustrating the configuration of the undercut in the butt portion of the bowling pin prior to aflixing the base pieces.

FIG. 3 is a cross sectional view of the preferred structure of the inner cylindrical ring member.

FIG. 4 is a cross sectional View of the main base member.

FIG. 5 is a cross sectional view of the undercut in the butt portion of the pin with the inner cylindrical ring in place and showing partial insertion of the main base member.

FIG. 6 illustrates in a cross sectional view an enlarged fragment of the arrangement of FIG. 5.

FlG. 7 illustrates in perspective the preferred construction of the inner cylindrical ring member.

FIG. 8 illustrates in perspective the main base member.

FIGS. 9 and l0 are cross sectional views similar to FIGS. 3 and 4, respectively, illustrating an alternate embodiment wherein a locking bead is formed in the inner ring and a cooperating groove in the outer member.

Referring in greater detail to the gures, a wooden bowling pin body l of usual shape is shown with the butt comprising an undercut portion 2 forming a projecting core fl. Abutting the core 4i, an undercut in the pin base comprising a downwardly facing groove 5 is formed between a cylindrical wall 3 and the core ll. At the upper extreme of the core 5, an outwardly facing locking groove 6 is provided. As seen in FIG. l, the base insert lll is positioned in the undercut and the skirt portion thereof forms extensions i3 and ltofthe bowling pin bottom and tapered side, respectively at the juncture of the bottom surface and side surface of the pin. The base piece lil is preferably formed of a durable impact and chip resistant material. Any of the commercially available resinous compositions having these properties may be employed. illustrative examples are such as nylon, cellulose acetate butyrate, acetal resin marketed under the brand name Delrin, ethyl cellulose, polyethylene, polypropylene, polycarbonate, vinyl chloride and the like may be used.

In alixing the base to the pin, more detail reference is made to FlGS. 3 5 of the drawing. In FIG. 5 the butt of the pin is shown with the inner cylindrical member i7 positioned in the undercut configuration of the bowling pin and the main base member lil positioned preparatory for press-fitting into locking relationship therewith.

The undercut of the pin comprises an annular shoulder portion 2, a downwardly facing groove 5, the projecting 'core i and the outwardly facing circumferential locking groove 6 formed in the core d. ln attaching the base of the invention to the pin body, the cylindrical ring or sleeve member i7 is first inserted into the undercut of the pin. The member 17 shown in cross section in FiG. 3 comprises a base portion i8 capped by a relatively more slender collar portion i9 terminating at the top in a locking bead 23 which is flexibly supported by, and flares radially outward beyond the outer Q eriphery of, the collar portion t9. When inserted in the undercut as shown in FIG. 5, the llexible locking bead 25 is not engaged in the locking groove in the core fl until flexed radially inwardly into locking position by the top of the main base member. The main base member lltl, comprises a skirt portion ill which conforms with the side taper of the lower end of the pin and a collar portion l?. which when press-fitted in the undercut, engages the locking bead at 22 (FlG. 3) pivoting the bead into locking relationship with the groove 6 thereby locking the two base members securely in the undercut of the pin. The operation which effects the locking of the base pieces occurs when the upper extremity l5 of the base lil engages the extension of 22 or t e ilexible upper portion of the ring member i7. This pivots the locking bead Z3 radially inward into the loci;- ing groove 6, thereby securing the components of the unit in the pin base.

As an auxiliary and optional locking feature, the ring member ll shown in FG. 3 may be provided with a locking groove in its lower extremity. Cooperating with he annular groove 2d is a locking bead le in the lower inside periphery of the base member l@ of FlG. 4. These two elements may be interchanged and so that the member 17 as shown in FlG. 9 is provided with an annular bead 25 and with the corresponding recess 26 being formed inthe base member of FiG. 1() in place of the arrangement illustrated in FIGS. 3 and 4. It is thus seen as the element 17 is inserted in the undercut and member it@ is press-fitted and locked in position, the shoulder Zl of the inner sleeve 17 and the shoulder forming the top of the skirt portion of member lil abut the horizontal undercut shoulder portion of the pin butt; the flexible cap 23 is pivoted into the locking groove 6; and the locking bead t6 is iitted into the groove 2li.

The truste-conical tace of the main base member l@ forms an extension 2id of the side of the pin and the face 13 an extension of the bottom of the pin. If desired, the bottom face 2G of the annular cylindrical ring member 1'7 may be lush with the bottom of the pin or it may be recessed slightly, if so desired.

Each of the two members of the base insert is preferably prefabricated to produce a snug fit. Generally the members are sized so that the inside diameter of the member 17 is several mils (Le. about 2-15 mils) smaller than the outside diameter of the core 4; the outside diameter of the member 17 several mils larger than the inside diameter of the unit it) irrespective of the bead extension ld, and the collar portion l2 of the units l0 several mils larger `than the outer cylindrical wall 3 of the undercut groove The uppermost flexible portion 23 of the ring member has been illustrated in a substantially triangular cross lsection but it is apparent that this shape may taire any suitable configuration c g. circular, oval, square, etc. Further although a serrated structure is shown for the portion Z3, a solid annular ring may be utilized with good results.

The composition of the pin structure to which the base of the invention may be applied is not critical. It may be a conventional Wooden pin i.e. of solid or laminated wood structure or it may be formed from any of a varie-ty of materials such as metals or plastics, eg. foamed or blow molded structure, which have properties, such as rebound characteristics, substantially the same as those of Wood.

The life of the base member itl is dependent to a substantial extent on the material from which it is con- Y structed. When the pin itself is oi exceptional durability, it may be desirable to replace the base one or more times. In this operation any suitable device or tooling arrangement which forces the extraction of the base piece l@ as against the sleeve member t7' may be employed. For this purpose, for example, a tool gripping at the shoulder of ember itl and pulling downward with an applied at the base 2t? of the sleeve Si vill eilfect extraction of the base.

While the present invention is illustrated and described in connection with a speciiic arrangement, it should be understood that the invention is not limited precisely to the structure illustrated and described, but includes modifications that are obvious to one skilled in the art in the light of the inventive improvement herein provided.

l claim:

l. In combination a bowling pin having its butt end provided with an undercut at the juncture of the bottom surface and the side surface of the pin forming thereby an outwardly projecting central core, a circumferential outward facing locking groove at the top of said core, said undercut extending into the body of the pinV adjacent said core and forming a downwardly facing annular groove leading to said circumferential locking groove, an inner cylindrical ring member in said undercut substantially coextensive in length with said core and containing an upper integral ilexiblc annular laterally deflected portion, said portion having a contour such that as deiiected it substantially fills said locking groove in the core, an annular base member of length substantially coextensive with said core comprising an annular skirt portion forming the junction for the bottom and side of the pin and, integral with said skirt portion, an upright collar portion encircling said core and extending into said annular groove, the top of said collar portion engaging and deflecting the flexible annular portion of the inner ring member into the outwardly facing locking groove of said core thereby locking both members in said undercut.

2. The combination of claim l wherein said flexible annular portion comprises a serrated construction.

3. The combination of claim 1 wherein said inner cylindrical ring has an auxiliary annular securing bead formed on the outer periphery of said ring intermediate the deticcted upper portion and the bottom thereof and said base member has a corresponding annular securing groove formed on its inner periphery and coacting with said auxiliary bead to further restrict the intermovementV of the two members.

4. The combination of claim 1 wherein said inner cylindrical ring has an auxiliary annular securing groove formed at the outer periphery ot said ring intermediate the dcected upper portion and the bottom thereof and said base member has a corresponding annular securing bead at its inner periphery and coacting with said auxiliary groove to further restrict the intermovement ot the two members.

5. A two piece combination bowling pin base for attachment to a shank formed at the bottom of a bowling pin, said base comprising an inner cylindrical sleeve member provided with an integral serrated top portion which is iiared radially outward beyond the outer periphery ot said sleeve and arranged to be fitted over a shank formed at the bottom of a bowling pin and an annular outer main base member adapted to be joined in press-fitting relationship over said inner member, said main base .iernber comprising a trusto-conical skirt portion which provides the junction of the bottom and tapered side of a bowling pin and an upright integral portion which is adapted to encircle said inner sleeve member, said serrated top portion of the inner sleeve member being flexed radially inwardly bythe top of the upright portion ot said base member when said inner member is assembled with said main base member.

6. In combination a bowling pin having its butt end provided with an undercut at the juncture of the bottom surface and the side surface ofthe pin forming thereby an outwardly projecting central core, a Vcircumferential outward facing locking groove at the top of said core, said undercut extending into the body of the pin adjacent said core and forming a downwardly facing annular groove leading to said circumferential locking groove, an inner cylindrical ring member in said undercut substantially coextensive in length with said core and containing an upper integral flexible annular laterally deflected portion, said portion having a contour such that as deflected it enters said locking groove in the core, an annular base member of length substantially coextensive. With said core comprising an annular skirt portion forming the junction for tbe bottom and side of the pin and, integral with said skir-t portion, an upright collar portion encircling said core and extending into said annular groove, the top of said collar portion engaging and deflecting the exible annular portion of the inner ring member into the out- Wardly facing locking groove of said core thereby locking both members in said undercut.

Rer'erenees Cited in the ile of this patent UNITED STATES PATENTS 1,580,688 Sheldon Apr. 13, 1926 1,718,309 Sheldon June 25, 1929 2,680,023 Ellis June 1, 1954 2,809,038 Scheidemantel et al. Oct. 8, 1957 2,814,835 Faulkner Dee. 3, 1957

Claims

6. IN COMBINATION A BOWLING PIN HAVING ITS BUTT END PROVIDED WITH AN UNDERCUT AT THE JUNCTURE OF THE BOTTOM SURFACE AND THE SIDE SURFACE OF THE PIN FORMING THEREBY OUTWARDLY PROJECTING CENTRAL CORE, A CIRCUMFERENTIAL OUTWARD FACING LOCKING GROOVE AT THE TOP OF SAID CORE, SAID UNDERCUT EXTENDING INTO THE BODY OF THE PIN ADJACENT SAID CORE AND FORMING A DOWNWARDLY FACING ANNULAR GROOVE LEADING TO SAID CIRCUMFERENTIAL LOCKING GROOVE, AN INNER CYLINDRICAL RING MEMBER IN SAID UNDERCUT SUBSTANTIALLY COEXTENSIVE IN LENGTH WITH SAID CORE AND CONTAINING AN UPPER INTEGRAL FLEXIBLE ANNULAR LATERALLY DEFLECTED PORTION, SAID PORTION HAVING A CONTOUR SUCH THAT AS DEFLECTED IT ENTERS SAID LOCKING GROOVE IN THE CORE, AN ANNULAR BASE MEMBER OF LENGTH SUBSTANTIALLY COEXTENSIVE WITH SAID CORE COMPRISING AN ANNULAR SKIRT PORTION FORMING THE JUNCTION FOR THE BOTTOM AND SIDE OF THE PIN AND, INTEGRAL WITH SAID SKIRT PORTION, AN UPRIGHT COLLAR PORTION ENCIRCLING SAID CORE AND EXTENDING INTO SAID ANNULAR GROOVE, THE TOP OF SAID COLLAR PORTION ENGAGING AND DEFLECTING THE FLEXIBLE ANNULAR PORTION OF THE INNER RING MEMBER INTO THE OUTWARDLY FACING LOCKING GROOVE OF SAID CORE THEREBY LOCKING BOTH MEMBERS IN SAID UNDERCUT.