US2395864A - Racket - Google Patents

Description

G. k. GEERLINGS ETAL RACKET Filed April 1, 1941 2 Sheets-Shee t 1 Mn mw m W Nw lNVE " Gera Patented Mar. 5, 1946 RACKET Gerald K. Geerlings, New Canaan, Conn., and James N. Tynan, Chicopee, Mass., assignors to A. G. Spalding & Bros. Inc., Chicopee, Mass., a

corporation of Delaware Application April 1, 1941, Serial No. 386,278 7 8 Claims. $01. 27373) This invention relates to sport racketspsuch as are used for tennis, badminton, squash, etc., and particularly to rackets adapted topossess a resilient action in play. It relates to the connect- I ing members joining the handle and bow portions 3 of sport rackets, and also to means for controlling the moment of inertia, flexibility, center of balance, length of stem, weighting and other properties of sport rackets.

Ordinarily the ends of a wooden bow member of a racket are extended downwardly to cooperate with flank members to constitute a handle, as exemplified by the drawings in Williamson Patent 1,630,683, May 31, 1927, hereinafter sometimes designated as a conventional racket. However, the bow has sometimes been formed separately from the handle, as exemplified by the disclosure of Reissue Patent 20,684 to John B. Dickson, April 5, 1938. A racket of the type illustrated in said patent will hereinafter sometimes be designated as a Dickson racket. It includes a single resilient metallic stem connecting separate bow and handle sections,

sidewise movement refers to movement of the bow with respect to the handle in the plane defined by the stringing. Arcuate movement or rotational movement refers to movement of the bow with respect to the handle about the longitudinal axis of the handle. Backward and forward movement refers to movement in a plane including the longitudinal axis of the handle, said plane being perpendicular to the plane of the stringing. Sport rackets inherently possess at least an'infinitesimal trace of sidewise resiliency, arcuate resiliency and forward-backward resiliency.

Athletes difier greatly regarding the desiredamount of each of said resiliencies. Heretofore,

there has been no satisfactory method of or structure for providing exactly the desired degree of each of .said resiliencies in a sport racket; or, at

least such characteristics were not interchange-' ably provided in individual rackets.

Some players prefer heavy rackets and others desire rackets of light weight. Heretofore, storekeepers have sometimes had to stock several weights of each model of racket. Similarly, some players prefer long stems; some prefer short stems; and others prefer stems of medium lllgth. There has also existed a lack of uniformity of preference regarding not only such properties of rackets as flexibility, stem length and racket weight but also such properties as center ofbal ance, type of handle, moment of inertia and other have had to stock large quantities or rackets to supply the demand of particular sportsmen];

Sport rackets have heretofore been bulky'when packed for shipment. -Moreover, they have occupied considerable space in the store; Because rackets are in demand only during certain seasons in many sections of the country, storage space for the out-of-season goods constitutes-an important problem for the storekeeper. It isan important object of the'present inventionto provide a racket in which the amount of resilient backward and forward movement of the bow relative to the handle can be accuratel controlled and/or adjusted. a a V Other objects are: to substantially eliminate all sidewise movement of the bow; to provide a racket in which the amount of resilient absorption of the arcuate force can be accurately controlled and/or' adjusted; to provide a racket having adjustable weighting means; and to provide sport rackets which can be easily modified to fulfill a specific set of requirements not only as to the aforementioned resiliency and Weighting means, but also as to length of stem, center of balance, type of handle, moment of inertia of the bow about the longitudinal'axis of thehandle, moment of inertia of the racket about the average instantaneous center. of the racket in play, and other properties. a 1

It is an object of the present invention to provide a racket requiring a minimum of space for shipment and/or st'orage. A further object of the present invention is to provide a process of economically manufacturing rackets. p

An important feature of the present invention is the provision of a racket having a plurality of flexibly resilient shafts-adaptedto provide ,a predetermined amount (inflexibility of forward and backward movement of the bow and to substantially prevent any sidewise movement of the bow.

Another feature of the present invention is the provision of a variety of metallic shafts differing as to flexibility, length, weight andjother prop,

erties.

Another feature is the provision of a process by which a racket can be readil assembled by .a storekeeper, according to the specific requirements of a customer as to flexibility, length of properties of rackets- Heretoiore, storekeepers stem, center of balance, moment of, inertia, typ of handle and other such'properties. 3 1

Another feature is the, locating, of stem'members an appreciable distance fromlthe longitu dinal axisofthehandla; i

Another feature of thepresentinvention "the etc.

2" provision of weights which can be positioned in the stem, bow and/or handle for the purpose of controlling the weight, center of balance and moment of inertia.

Other objects, features and advantages will hereinafter appear.

Referring now to the drawings, it will be seen that: a

Figure 1 represents a front view of a preferred form of the present invention. 7

Fig. 2 is a front view of an alternative form of the present invention.

by the adhesive 23. For example, if a heat-sensitive material is used the assembly may be heated so that the adhesive material 23 is forced into some of the pores of the wooden throat member l3 and handle I1, and so that the cloth sleeve 22 is securely adhered to the metallic shafts 2| and to handle I! and throat membe |3. If it becomes desirable to change the metallic shafts, the heat-sensitive adhesive material 23 can be heated and the shafts withdrawn from the holes.

. I It should be particularly noted that the shafts Fig. 3 represents a detailed front view ofa portion of Fig.2.

Fig. 4 represents another alternative form of the invention. a

Fig. 5 represents a detailed plan view of 2. tion of Fig. 4. V v

Fig. 6 is a diagrammatic representation of sidewise movement.

Fig. 7 is a I diagrammatic representation of forward and baokwardmovement. V I

Fig. 8 is a diagrammatic representation of rotational movement. 7 g g Fig. 9 is a fragmentary view representing a modification-of a portion of the present invention.

Fig. 10 is a perspective view of the balance control weight.

Fig. 11 is a fra'gmentary view of a modified form of shaft.

Before describing the present improvements and mode of operation thereof in detail it should be understood that the invention is not limited to the details of construction and arrangement of parts shown .in the accompanying drawings, which are merely illustrative of the present preferred embodiments, since the invention is ca-- pable of other-embodiments, and the phraseelogy employed is for the purpose of description and not of limitation.

In a preferred and simple form of the inven- 'tion shown in Fig. '1, there is provided a racket .HJ havinga bow formed by bending a peripheral member l2vv such as a laminated ash' strip into a closed curvilinear shape such as an oval. Stringing maybe secured to. the bow in the usual manner. .A throat :member 13 is glued to a portion of the bow H and is provided with holes l4 defined'by cylindrical Walls l5 and end walls 16.

Positioned apart from the bow 1 is a gripping member such as a handle providedwith bores |8 each defined by a cylindrical wall It and an end wall 20.

Of particular importance it should be noted that a plurality of :metallic shafts 2| connect the handle l1 and the bow II. The upper ends of the shafts '21 pass into the hole I4 of the throat member l3. .Interposed between the shaft 2| and cylindrical walls 15 of the holes M are cloth sleeves 22 containing heat se'nsitive adhesive material 23 such as thermoprene, polystyrene, Glue, Bakelite or other adhesive material may be used if desired. The shafts 2| ar ainxed to the handle I! by the cloth;sleeves 22 and adhesive 23. The shafts abut against the end walls l6 and ofthe throat member 3 and handle 11, respectively.

The process of manufacturing the racket iii includes the steps of forminga bow H, placing the sleeves 22 and the shafts12| in the holes [4 and I8. The handle l7, throat member l3, shafts 2| and cloth sleeves. 22 are then securedtogethe'r por 2| are positioned so that their axes lie substantially in the plane defined by the bow H of the racket H), which plane also contains the longitudinal axis of the nonmetallic the shafts 2| handle l1. Thus, (sometimes herein designated as members or connectors) brace each other to sub- 'stantially prevent all sidewise movement of the how relative to the somewhat cylindrical handle I7. Sidewise movement is diagrammatically represented in Fig. 6. Because the shafts of the racket lllare both in the same plane, a rel- .atively high'degree of flexibility and resilient backward and: forward flexing movement (diagrammatically represented in Fig. '7 is possible, provided reasonably flexible materia1 is used fo fthe shafts. Thus, the racket H! can have the characteristic of absorbing shock and of absorbing a substantial amount of shock, so that the hand receives relatively little shock even when a ball isdriven a considerable distance. If, however, it is desirable to change the racket to a stiff .rac-kelg it is only necessary to remove the flexible shafts and substitute stiff shafts. The cost of substituting shafts is only a small portion of the cost of substituting an entire racket.

Attention is directed to the fact that if the racket is provided with very stiff shafts not only :sidewise and backward and forward movement is prevented but rotational movement is also prevented, inasmuch-as the two shafts brace each other in preventing rotational movement. A Dickson racket permits a certain amount of rotational movement .inasmuch as a metallic member inherentlyhas torsional resiliency. The Dickson racket is able to function somewhat as .a torsional pendulum. The .racket l0, however, may be provided with two off-center rigidly stiff stem members adapted to brace each other to minimize rotational movement. Moreover, rotational movement of the bow is decreased by the increased moment of inertia, incident to positioning the weight of the .stemmembers a substantial distance from the cylindrical axis of the handle. Rotational movement is also resisted by the stillness of two members instead of one. In the alternative form of the invention shown in Figs. '2 and '3, there is provided a racket 26 somewhatjsimilar to the racket ID .shown in Fig. 1, but differing therefrom in the following part culars. In addition to the two off-center shafts 2| the racket 26 is provided with a central shaft 2'! of tubular shape. The sha-ft 27 is secured to the how 1 and a handle 28 by means of the adhesive '23 impregnated sleeves 22 and cap nuts 29 and 30.- Within the central shaft 21 is a weight 3| to which is attached an endless belt 32 of rawhide, nylon or the like, which passes through an eyelet 33 .on the cap nut 29, through ahole 34 in the weight 31, and through hole 35 in the cap nut 30. A loop 36 of the belt'32 is frictionallypositioned -between the cap nut 30 and .a cap 31.nor-mallyfl-tting onto an end of the handle 28. Thus, theweig-ht 3| issecurely positioned within the central shaft 21 by means of the endless belt 32 which cannot move because of the frictional gripping by the cap 31, and cap nut 30. However, when the cap 31 is removed, the loop 36 is free and can be used to move the endless belt 32 and to thereby move the weight 3| along the cylindrical axis of the central shaft 21.

It should be particularly noted that the racket 26 has shafts 2| having ends in abutting relation with end walls H5 and 25 of the bores l4 and N3 of the throat member l3 and of the handle 28, thereby preventing the throat member and handle from coming any closer together. The central shaft 21 and the cap nuts 29 and 30,

however, prevent the throat member I3 and han-, die 28 from going farther apart. Thus, the racket 26'includes a doubly effective securing means to maintain the bow, handle and shafts detachably but normally firmly together, said means including the adhesive-impregnated cloth sleeves 22,

and grooved cover block 42 is detachably secured to the throat member 40 by means of screws 43 and is normally allowed to press firmly substantially against aplurality of the shafts 44 and against a bottom face 45 of a cavity 45 of the throat member 40. Grooves 41 are provided in the bottom face 45 adapted to position a plurality of the shafts .44. Flanges 48 of the shafts 44 fit within slots 49 provided in the bottom face 45 of the cavity 46. A plurality of the slots 49 may be provided for each groove 41, so that the length of a stem 53 of the racket 39 can be adjusted, not merely by the use of shafts 44 having a suitable length, but also by the positioning of each fiange 48 in the most suitable one of the slots 49. The slotted and grooved cover block 42 cooperates with the slots 49, grooves 41 and cavity 46, and throat; member 40 and screws 44 to constiute aclamp 5| securely maintaining the bow 38 and the stem5|l together,

Attention is directed to thenovel weighting:

means provided in the racket39. it weight 52, such as a rubber-covered lead plug, or a lithargefilled rubber plug, is placed in a cavity 53 at the end of the shaft 44. The shaft 44 is bifurcated to provide a slot 54 which is expanded by the weights 52 as the latter is inserted between the two fingers of the bifurcated shaft 44. When the clamp 5| is tightened by securing the block 42 to the throat member 4|lby means of the screws 43, the weight 52 is held firmly by the two fingers of the shaft 44, which are brought closer together by the action of the clamp 5|. The clamp 5| can be adapted to additionally secure the weight 52 and/or other Weights. 55 may be placed in the groove 41 and may be positioned by the slot 49 in the bottom face 45. In any case, the clamp 5| additionally secures the weight when the screw 43 is tightened. The weight 52 may have a higher density at the tip than at the head, and in this manner the balance of the club may be adjusted along the longitudinal axis of the stem 50. r I

It should be noted that the novel weighting means provided by the present invention makes it possible, not only to alter the total weightof 7 :13 the racket, but also to alter the position of the weights. The center of balance, or leverage weight, can thereby. be materially-modified in a racket without changing its. total weight. 0i."

even greater importance, however, the. moment of inertia of the racket can be modified by;.rea'son of the fact that the weights may be'positioned at substantially any point from the end ofthe handle to the bow. Moreover, the weightscan be positioned to effect asidewise weighting to compensate for tendencies toincorrectly hit the racket, or for other reasons. When weights are positioned in each of'theoutermost of the shafts 44, the rotational moment of inertia is'increased, so that the tendency of the bow to rotate with respect to the handle (see Fig. 8) is decreased. Because at least some of the metallic shafts are positioned apart from the axis of rotation, the

metallic shafts themselves increase. the moment of inertia of the stem to decrease the tendency of the bow to rotate. Fig. 8 schematically shows the arcuate or rotary movement of thebow wit respectto the handle.

A ferrule 56 is disposed over the throat member 40 andrelated parts so'that the inter'engaging means 4| is normally covered. Similarly a ferrule 51 covers an interengaging means 58 by which the shafts 44 are attached to a handle 59. The interengaging means 4| and 58 are substantially similar and function topmake possiblethe V convenient separation of the handle 59, stem 50 and bow 38. v

The adjustable length-structure and weights 52 and 55 hereinbefore described in connection with the bow end of the racket 39'may alternatively and/or additionally be similarly incorporated in the interengaging means 58 at the handleen'd.

Particular attention is directed to the fact that the shafts 44 are easily detachable from the handle 59 and bow 38'.

If the ferrules 56 and 51 are slid down, and if the blocks 42: are removed, the shafts 44 are thereby exposed for removal. Thus, it is possible to manufacture bows 38',

handles 59 and shafts 44, and to store them compactly. Then when a racket of a given set of requirements is ordered, it may be built according to the customers requirements;

Alternatively, the bows, handles and shafts may be packed compactly and shipped to a storekeeper. It should be particularly noted that the disassembled racket 39 requires very little space for shipment or storage. Both conventional rackets and Dickson rackets are bulky in ship-.

ment and storage. Packagingbows, stem shafts and handles separately makes possible a'high degree of compactness. Storekeepers can assem ble a few rackets to demonstrate the wide range of properties which are possible by means of the many varieties of detachable metallic shafts of divers properties, making at least one racket with 7 very flexible shafts, so that the racket possesses For example, a weight 7 a great amount of resilient backward and forward movement, diagrammaticallyrepresented in Fig. ,7, and making some with very rigid shaft to provide an illustrative racket having substantial ly no resilient backward and forward movement. After customers have tried illustrative rackets to make certain of the properties which they desire, thestorekeeper can, in effect, build custom-built rackets according to the customers requirements. Inasmuch a there is a great lack of uniformity among athletes regarding each of the properties of a racket, such as length of stem, flexibility, center of balance, typ of handle, mo

mentof inertia, the possibilityof-the storekeeper properties; forming a plurality of handles of divers properties; forming a plurality of metallic shafts of divers properties; forming a plurality of weights; determining the specific requirements for a racket; selecting a suitable group from said hows, handles, weights and shafts; and assembling saidgroup to provide a racket including a .rhowya :handle and :a plurality of metallic shafts .therebetween, complying with said requirements and having a-custom-built set of properties.

Although the shafts have generally been illushtated :as .cylmdrically tubular, it should be un- -=derstocd that other shapes may be used. It .should. -be particularly noted that a tubular memher, when provided with a longitudinal slot or slots, permits substantially greater flexibility in one direction than in another. In Fig. 9 there is shown a shaft 60 having two slots 6|, a transverse .slot axis 62 passing through the slots 61 and perpendicular to the longitudinal axis, two segments I63 and. a transverse segment axis 64 passing through the midpoints of the segments. The segment axis 64 is perpendicular to the slot axis 62 and to the longitudinal axis of the shaft $11.. A given force will produce a greater amplitude of flexing of the shafttfl about the slot axis 62 than about the segment axis 64. Moreover,

the shafts can be arcuately adjusted. Thus, a rackethaving slotted shafts can be changed from one having little backward-forward resiliency to onehaving a substantial degree of such resiliency :bymerely arcuately adjusting the slot axis 62 of shafts by rotating them ninety degrees. The shafts iii! are preferably detachably attached to the bow and handle, as by clamps 5i, and it is a simple matterto merely loosen the clamps to thereby loosen the shafts, and to rotate at least one, and preferably all of the shafts ninety or less degrees to modify the resilient characteristics :of the racket by positioning the slot axes 62 at the most suitable of divers resilient positions.

Furthermore, .the shafts 21, 21, 44 and so new inbefore described extending between and connecting the separate bow and separate handle ,may all or interspersedly be of solid or tubular .wood, or. of material other than tubular metal.

For. example, referring to Fig. 2, the center shaft 2?! may be of tubular metal as shown and the two side shafts ii of wood, vice versa, or all three maybe of wood. Furthermore, although there are certain advantages in having shafts, such as the shafts .21, bottoming in the bow and/orzthe handle as shown, it is possible to make the holes full length .so that they extend through the bow and/or the handle similarly to the shaft 21. Also, slots, such as the slot Si in shaft'lill,

may be provided in any of the foregoing wood and other alternative shaft constructions, for divers degrees of flexibility. I

.As shown'in Figs. 1 and 10, the shafts may also serve asa guide and holding means for an external adjustableweight 66 including weight plates .81 and 58 with channels 69 adapted to engage and grip the shafts 21, for example, when ascrew [0 passing through plate .69 is tightened Ina conventional screw-thread connection with 6 8. -'I'hew eightfi5is tightenedronthershafts in near the how when it is desired to have the new section additionally weighted, or near the or more of the weights =66 or H may be used on .a single racket.

With weights such as "66 or H underweight rackets can be brought up to or over regulation weight, and standard weight rackets can be made heavier, if desired.

Fig. 11 shows a modified form of shaft 12, which maybe used in place of shafts 21, 44 or 60, including the provision of one or more depressions 13 which tend to stifien the shaft against bending in a plane tangential to the depressions. Such a construction may be used in place of the slot 6| to achieve the control and adjustable resiliency advantages described 'hereinbefore in detail in connection with Fig. '9.

Other variations and modifications may be made the .scope of this invention, and portions of the improvements may be used without others.

Having thus described the invention what is claimed as new is:

1. In a racket, the combination of'a wooden how; a handle; a plurality of metallic connectors extending between the bow and handle; and means including clamping members detachably associating the connectors with the bow and with the handle and a disengaging fastener adapted to normally maintain the clamping members pressing toward each other and substantially against theconnectors.

2. In a racket, the combination of a wooden how; .a handle spaced apart from the bow; a plurality of metallic connectors; enlarged heads at each end of the connectors; detachable securing means associated with the bow and with the handle, adapted to normally engage with the enlarged heads to securely fasten the ends of the connectors to theubow and handle.

:3. In a racket, the combination of a wooden how; a handle spaced apart from the how; a plurality of metallic connectors; weighting means adapted to fit at least partially within the connectors; and asingle means cooperable in maintaining said connectors relative to said bow and said weighting means relative to said connectors.

4. In a racket, the combination of a wooden how; a handle spaced apart from the bow; a plurality of metallic connectors for uniting the bow and handle, and at least one having a cavity; weighting means within the cavity and a single means cooperable in maintaining said weighting means in a selected position Within said cavity and said connectors relative to said bow.

5. 'In a sport racket, the combination of a bow; a handle; a plurality .of separate members connecting said bow to the handle; and interlocking means associated with said members and having a plurality of positions for maintaining said how in divers longitudinal positions relative to said handle. Q

6. In a sport racket, the combination of a bow; a'hand-le; a plurality of separate members conmeeting said bow to the handle; and means for altering the resiliency of said bow relative to the handle, said means including interconnecting meanslenabllng adjustment of said connecting members in divers positions relative to said handle and said how.

'7. In a sport racket. the combination of a bow;

a handle; a plurality of tubular members con-- necting said bow to the handle; an external weight shiftable upon said tubular members and having portions embracing said tubular members; and means for locking said weight in divers positions upon said tubular members and said tubular members together.

8. In a racket, the combination of a bow; a

handle; a. plurality of connectors intermediate said handle and said bow, at least one of said connectors having a cavity therein with thewalls thereof being laterally 'distortable; weighting meansin said cavity; and clamp means for gripping said connectors, maintaining said connectors and bow together, and laterally pressing said at least one of said connectors to grip and hold said weighting means in the cavity therein.

GERALD K. GEERLINGS. JAMES N. TYNAN.

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