Bat

Abstract: A perforated bat for playing games such as paddle tennis, tether ball and others, has a monolithic unstressed striking head which comprises a pair of outer lattices which form the striking surfaces; and these lattices are joined by a third internal core lattice which has at least one longitudinal and one lateral web spanning the two outer lattices.

Description: FIELD OF THE INVENTION This invention relates to a bat for playing games and in particular, for playing games such as paddle tennis, tether ball, beach tennis and like games involving tennis balls or the like. BACKGROUND OF THE INVENTION It has been recognized that the thickness of such bats is important from the po int of rigidity and for a good striking feel but, of course, consideration has to be had to the mass ofthe bat as well as its balance. Thus, it has previously been proposed to provide a bat which includes a handle and head, the head including an unstressed monolithic perforated structure and having a pair of spaced-apart lattice structures, the two outer surfaces ofwhich constitute the striking surfaces and the inner surfaces being joined together by a plurality of discrete transverse struts. In this specification the term "lattice structure" (or lattice) is intended to refer to lattice or grid structures thin in relation to lengths and breadths, which are perforated by a series of openings of a variety of shapes. In a particular form of the invention the structure is a lattice comprising intersecting laths, which may be straight, curved or otherwise shaped and which may intersect at various angles. In a preferred form of the invention the two spaced apart lattices are formed by intersecting laths and are joined by means of discrete transverse struts spanning corresponding intersections of the laths, as weU as the outer frame or rim of the head of the bat which runs around the periphery of the lattices and to which the handle is attached. Further, according to the invention, some of the interstices in the latticed striking surfaces may be webbed and it is further preferred that alternative interstices be webbed to constitute a checkered pattern. This bat has a striking head which can be described as being of double lattice construction - the outer faces of the two lattices constituting the striking faces. This construction enables the head of the racket to be relatively thick in construction, much of the rigidity being imparted by the depth or width of the "frame" running around the periphery of the striking head. The interior of the bat is relatively hollow - apart from the internal cross struts and is therefore relatively high. A bat of this construction is covered by U S Patent No. 4 411 427 (Baumgartner). OBJECT OF THE INVENTION It is an object ofthe present invention to provide a perforated bat which has better rigidity than that provided by bats or double lattice design as described above, and particularly that ofU S Patent No. 4 411 427 (Baumgartner). THE INVENTION According to the invention there is provided a bat for a game including a handle and head, the head including a monolithic unstressed perforated structure having a pair of spaced apart out lattices; the two outer surfaces of the lattices constituting the striking surfaces of the head, the inner surfaces of the lattices being interconnected by a plurality of discrete internal cross struts spanning at least some of the intersections of the outer lattices, characterized in that certain but not all of the rows of cross struts define the elements of a core lattice which extend across the interior of the head in selected paths and intersect with each other and/or with the outer rim of the head to form such core lattice. In addition, it should be noted that in this specification the term "monolithic" in relation to the structure of the head of the bat is intended to mean a structure of seamless homogeneous unitary construction of the type which, for example, but not necessarily, may be provided in the manufacture of injection moulded plastic components. In this specification the term "core lattice" is intended to include a structure comprising elements as defined above, and in one non-limitative example there are longitudinal and lateral elements spanning the head ofthe bat and making up, with the outer rim of the bat, such core lattice . Furthermore, while the core lattice is intended as an internal structure extending across the interior of the bat head, it should be noted that being part of a monolithic structure, the core lattice interfaces and co-functions with those sections of the two outer lattices adjacent to where the core lattice is located, and that these sections of the outer lattices form an extension of the core lattice and therefore serve a dual function, as being both part of the outer lattices, as well as an extension of the core lattice. It is therefore specifically clarified that the structure of the core lattice will, in this way, co-function with the adjacent sections of the outer lattices in the same way that the cross struts not part of the core lattice also interface and co-function with the outer lattices. Furthermore, it should be noted that the core lattice is intended as a complete lattice structure in its own right, which is located in chosen locations only, incorporates selected elements only of other lattice structures and constitutes a lattice additional to any other lattices. As this invention deals with a monolithic structure it is appropriate when referring to the outer lattices and the core lattice, that the location and boundaries between these two parts of the bat head which abut each other be clearly identified and defined for purposes of this patent. In this regard, the outer lattices can be fairly described as the flat outer structures of the bat head used to strike balls, or other similar objects. If the outer lattices are incrementally ground or shaved away from the bat in the plane of such lattices, they wiU cease to be able to effectively perform this function at the point where the outer lattices no longer present an unimpaired striking surface, or the ends of any internal cross struts become exposed. It is at this point that the outer lattices terminate, and any remaining structures inside the bat head such as the core lattice will not be part of the outer lattices and will be situated in the interior of the bat head, and can be described as internal structures. The core lattice will be characterized by having relatively few elements making up such core lattice compared with the two outer lattices. In a preferred form of the invention, the outer lattices will not include interstices or gaps more than 25mm in size measured in any direction across such interstices, so as to reduce uneven ball "bounce" on impact. The elements of the core lattice however, may include interstices between such elements which are preferably at least 40mm in size. Another characteristic of this invention is that the webbed sections of the internal elements making up the core lattice are relatively thin, compared to the elements making up the outer lattices. In this preferred form of the invention the laths making up the outer lattices will be of the order of at least 1,5mm to 2mm thick in order to be strong enough to resist damage when striking a ball in play. The thickness of the webbed sections of the internal core lattice will however, be substantially thinner, being of the order of approximately 0,75mm. In a preferred form of the invention the core lattice includes at least two longitudinal and two lateral elements . These latter elements will coincide with intersections of the two outer lattices and may be symmetrically located with respect to the head structure. Other intersections of the spaced-apart outer lattices may be joined by means of cross struts and it will be appreciated that the elements will coincide with certain rows ofstruts and, in fact, the elements may comprise rows of struts with connecting webs there-between. The webs may be of the order of 0,75mm so that the mass of the bat is kept to a minimum. One of the design features of bats of this type is that the design of the two outer lattices is robust and strong enough to resist any damage caused in striking balls in play. However, these outer lattices protect and cover the elements of the core lattice which, although relatively thin, imparts great extra rigidity to the bat. If the elements of the core lattice were not so protected by the outer lattices, they would soon suffer damage not only because of their relative thinness, but also because they are normally relatively widely spaced-apart, and therefore would be susceptible to damage caused by blows from a ball which would be able to impart sideways stress to the elements, because the ball would penetrate quite deeply below the level of the plane of the outer edges of the elements being struck and thus impinge against the sides of the elements rather than the edges. In a preferred form of the invention the core lattice includes a zone bounded by elements of the core lattice at the centre or sweetspot of the bat, thereby providing additional rigidity and strength in this zone. It was surprisingly found that this zone may also be responsible for a distinctive different characteristic impact sound. There may be a difference in pitch, when a ball is struck in this central area, compared with the other areas ofthe bat head outside of this central zone. It appears that the pitch of such sound depends on the area of the central zone bounded by elements of the core lattice and similarly the pitch of the impact sound, when the ball strikes an area outside of the central zone, may also depend on the areas bounded by the elements of the core lattice (and possibly the surrounding rim) in these outer areas. A variation of the invention is for additional elements to be introduced in the central zone area, so as to break this area up into relatively small zones, compared with zones in the outer areas which result in the impact sound being relatively high in pitch when a ball strikes this area. The elements spanning the central zone will not span the whole head of the bat, but only the chosen area of the central zone. The lattices of the striking surfaces are preferably alternatively webbed to create in checkered pattern, with the webs on one surface being staggered in relation to those of the opposite surface. It has also been found that the webbed sections of the elements of the core lattice , lying between the internal cross struts connecting the two outer lattices, may be provided with one or more holes or apertures in the centre of such webbed sections, which saves weight and does not significantly affect the structural strength or rigidity of the elements. Such holes or apertures also provide bearing surfaces which touch and support the adjacent neighbouring structures of the mould in its closed position while the bat is being moulded, thereby contributing to the longevity of the tooling which produces the bat. A preferred form of the invention provides for one or more holes or apertures in the centre of each webbed section of the elements of the core lattice. EMBODIMENT OF THE INVENTION An embodiment of the invention is described below with reference to the accompanying drawings in which: Figure 1 is a plan view bat according to the invention; Figure 2 is a side view; Figure 3 is a section along the lines 3 - 3 of Figure 1; Figure 4 is a section along the lines 3B-3B of Figure 1; Figure 5 is a simplified three dimensional exploded view of the bat showing the three lattices but excluding for clarity, the internal cross struts, except where integral with the core lattice ; Figure 6 is a partial isometric view of a broken away section of the bat according to the invention; Figure 7 is a similar view to Figure 3 of a refinement of the invention; Figure 8 is an isometric view of a partial bat illustrating the internal core lattice, without the outer two lattices; Figure 9 is a similar view with the addition of a broken-away structure of the two outer lattices and the internal core lattice ; and Figure 10 is a sketch in enlarged sectional side view, of a very small portion of the bat to illustrate the nature of the core lattice . The bat of the invention has a pair of spaced-apart striking surfaces 10 of webbed lattice construction. The surfaces may be regarded as being a lattice construction with alternate gaps 11 being webbed and in the embodiment, the resulting gaps are octagonal, having four long and four short sides. The inner surfaces of the two outer lattices are joined at intersections of the lattices by means of internal cross struts 12. A core lattice 14 inside the two outer lattices 10, is provided by internal transverse elements 16 running inside the two outer lattices along the lines 4-4 of Figure 1 and longitudinal elements 18 along the lines 5-5 of Figure 1, and as shown in Figures 5, 8 and 9. The intersections of the longitudinal and the transverse elements defines a zone 22 which covers the central area of the striking surfaces, thereby particularly reinforcing the bat where a ball is usually struck, and creating a characteristic impact sound. In Figure 7, the webs 20 have orifices 50 which save on mass and cost of the bat, without affecting its structural strength or rigidity. These orifices also serve to provide bearing surfaces which touch and support the adjacent neighbouring structures of the mould in its closed position while the bat is being moulded, thereby contributing to the longevity of the tooling which produces the bat. It will be appreciated that one or more such orifices may be provided. In Figure 8 the basic skeleton of a bat is illustrated and in Figure 9 a portion of the two outer lattices is shown on either side of the core lattice comprising elements 16 and 18. In Figure 10 a portion of the inner core lattice 18 is illustrated showing its relative width a in relation to the depth b of the outer lattices 10.

Claims: A bat for a game including a handle and a head, the head including a monolithic unstressed perforated structure having a pair of spaced apart out lattices <(10)>; the two outer surfaces of the lattices constituting the striking surfaces of the head, the inner surfaces of the lattices being interconnected by a plurality of discrete internal cross struts <(12)> spanning at least some of the intersections of the outer lattices, characterized in that certain but not all of the rows of cross struts define the elements of a core lattice which extend across the interior of the head in selected paths and intersect with each other and/or with the outer rim of the head to form such core lattice. The bat according to claim 1 characterized in that the core lattice includes at least two longitudinal elements and two lateral elements which intersect each other. The bat according to either of the above claims characterized in that the elements are symmetrically located with respect to the head structure. The bat according to any of the above claims characterized in that the elements are created by the addition of structural material to selected sections of the outer lattices which span the ends of the selected cross struts in such elements, in comparison with non-selected sections. The bat according to claim 4 characterized in that the elements are created by the addition of structural material between selected cross struts in such elements, so that the interstices are at least partly filled and webbed.

Inventors: GORMLEY IAN GAVIN, GORMLEY, IAN GAVIN
Applicants: EUROP SPORTS MERCHANDISING BV, EUROPEAN SPORTS MERCHANDISING BV
Application year: 1998
Main classification: A63B59
IPC codes: A63B49, A63B59