AU610695B2 - A racquet string straightener - Google Patents

Description

I~ZIUI~ Y- w v Signature of declarant(s) (no afItstation required) Note' Initial all alterations DAVI[.S COLLISON, MELbOURNE and CANBER 1- I I J OPI DATE 25/08/89 AOJP DATE 28/09/89 APPLN. ID 30441 89 PCT NUMBER PCT/AU89/00027

PCT

INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 International Publication Number: WO 89/ 06994 A63B 61/00, 51/00 Al (43) International Publication Date: 10 August 1989 (10.08.89) (21) International Application Number: PCT/AU89/00027 Dign e Ste ro)ADo patent), AU, BE (Eupea ate C ur n patent), DE (Euro- (22) International Filing Date: 27 January 1989 (27,01.89) pean patent), FR (European patent), GB (European patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), SE (European pa- (31) Priority Application Numbers: PI 6428/88 tent), US.

PI 7008/88 (3N) Priority Dates: 27 January 1988 (27,01.88) Published 29 February 1988 (29.02.88) With internatioial search report.

(33) Priority Country: AU (71)(72) Applicant and Inventor: UBL, Vaclav [AU/AU]: Winona Road, Mt. Eliza, VIC 3930 (AU), (74) Agents: HUNTSMAN, Peter, H. et al,; Davies Collison, I Little Collins Street, Melbourne, VIC 3000 (AU), amendments made und, r iecti d Annd is correct for i rinting (54) Title: A RACQUET STRING STRAIGHTENER V

I

is ,-22.

INN M IL~I IX]IL M 1,7 rzg Z JI 1221 IT f 13 I If 12 I IF IV 1 ~51~~3~31X,5 tE3 4 67 ~3 Fl 1~ ~Sz;(0 I' 14 (57) Abstract The racquet string straightening device (10) comprls: a support (12) from a planar face (13) of which a fixed array of teeth (14) projects, The teeth (14) are arranged in longitudinal tows (16) and intersecting transverse rows (18) wit passages between adjacent rows sized to receive the strings of a racquet, Alternate teeth (14) in each row are omitted from each row in offset manner so that the teeth r'ngage every other opening between the strings of the racquet. Every tooth in each longitudinal row (16) and every tooth in every transverse row (18) has the same width but the widths of the various rows vary according to a predetermined spacing of the strings of the racquet, Preferably there Is a central longitudinal row (16) and paired rows (16) on respective sides of the central row and spaced by the same number of rows from the central row have the satne width, L i WO 89106994 PCr/AU89/00027 A RACOUET STRING STRAIGHTENER This invention relates to stringed sports racquets, and is particularly concerned with a device for straightening the strings of an already itrung aid tensioned racquet, for example so that they extend in an appropriate orthogonal arrangement.

Many sports, such as te;uis, squash, racquetball and badminton use stringed racquets to hit a ball in the course of a game. The racquet typically has an elongated handle surmounted by a head which has a stringed planar surface adapted to hit the ball, Generally the head comprises a substantially circular or ovoid frame of wood, metal or composite material which supports an orthogonal array of interwoven, tensioned strings. Each opening between adjacent strings in the array is frequently a rectangle having sides of approximately 1cm, but some WO 89/06994 PCT/AU89/0 0027 2 variation in size and shape of such openings occurs between different sizes of racquets, i.e. as used for squash and tennis, and in any one racquet between most of the openings defined by the strings.

During play any one string tends to become displaced from its normal linear position in the array, as the strings come into frequent and often violent contact with the ball. The effects of displaced strings are numerous. For instance strings may be displaced away from particular regions of the head resulting in an area which imparts a diminished impetus to the ball. Further an area with an excessive or inadequate number of strings due to string displacement may not return the ball in a predictable trajectory.

In the past, players of racquet sports have attempted to straighten displaced strings with their fingers. This method is time consuming and may not return all the strings to their correct position.

Furthermore the strings tend to collect body oils and dirt from the player's fingers which may act to abrade and degrade the strings, particularly catgut strings. Various manual devices have been proposed for straightening the strings, all generally with unsatisfactory results.

British Patent Specification No. 8600316 describes a racquet string straightener having a movable row of teeth, each tooth having a complicated set of notches at its outer end. To use the device of this specification the teeth are manually adjusted to an appropriate distance along the length of the L_ c, .I WO 89/06994 PCT/AU89/00027 WO 89/06994 3 device to receive respective cross-wise strings.

When a single lengthwise string is pressed into the notches of the row of teeth, that string is straightened. As will be appreciated the device of this British Specification requires a certain amount of manual dexterity to use and in any case can oinly straighten a single string at any one time.

United States Patent Specification 4,733,866 discloses a similar arrangement in which each tooth in a single row of teeth can be inserted into a respective opening. Xt is suggested that the teeth or spacer pegs can have varied shapes as needed to part and position the racquet strings, but in order to correctly space the strings, the teeth must be closely received in the openings and it would be necessary to vary the teeth in the single row for each row of openings in the racquet to be straightened.

In contrast United States Patent Specification 4,489,942 proposes an array of teeth in intersecting longitudinal and transverse rows in which all of the teeth have the same size and are equally spaced. Although this patent specification suggests that in the area of a racquet head proposed to be covered by the device the openings between the strings are nearly square, in some racquets the differences between the widths of the openings may be upto 4mm or more for a mid-size tennis racquet and some of the openings may be out of square by more than 4mm, so that with this device the teeth would not only be the wrong size in many instances but many of the teeth would not be aligned with the WO 89/06994 PCT/AU89/00027' 4 corresponding openings.

United States Patent Specification 4,'389,523 has a similar problem with equally spaced and sized teeth but also proposes spacing the rows of teeth such that the teeth only engage every other row of openings. A disadvantage of this proposal is that if the strings in a row of openings not engaged by the teeth are displaced towards each other they will not be straightened by the device.

It is an object of the present invention to provide a racquet string straightening device in which at least some of the aforementioned disadvantages are alleviated.

In accordance with the present inventic:.

there is provided a racquet string straightening device comprising a support and an array of teeth fixedly projecting from the support, each tooth having an outer end and a portion supporting the outer end from the support and being shaped so as to be capable of being closely received within a respective opening defined in an array of strings of a racquet, the array of teeth comprising a series of parallel longitudinal rows of the teeth which intersects with a series of parallel transverse rows of the teeth, with every tooth in each longitudinal row having the same width and adjacent longitudinal rows being spaced apart at or adjacent the support by a distance substantially less than the width of any tooth in the adjacent longitudinal rows but sufficient to be capable of receiving a respective string of the racquet in straight man ier therebetween WO 89/06994 PCT/AU89/00027 and with every tooth in each transverse row having the same width and adjacent transverse rows being spaced apart at or adjacent the support by a distance substantially less than the width of any tooth in the adjacent transverse rows but sufficient tj be capable of receiving a respective string of the racquet in straight manner therebetween, the widths of the longitudinal and transverse rows of teeth varying according to a predetermined arrangement so as to allow for the teeth being closely received within the respective openings, and wherein adjacent teeth in each longitudinal row are spaced apart at or adjacent the support by a distance substantially comprising the sum of the width of a respective intersecting transverse row and the spacing of that transverse row from the two immediately adjacent transverse rows of teeth and adjacent teeth in each transverse row are spaced apart at or adjacent the support by a distance substantially comprising the sum of the width of a respective intersecting longitudinal row and the spacing of that longitudinal row from the two immediately adjacent longitudinal rows of teeth whereby the array of teeth has a checker board appearance.

Further according to the present invention there is provided a strung racquet and a racquet string straightening device therefor, said racquet having a head and a plurality of strings supported thereby, said strings being arranged in a series of substantially parallel main strings and a series of substantially parallel cross strings generally transverse to said main strings to define an array of openings between the strings which openings vary in WO 89/06994 pCT/AU89/00027 6 size and shape across the head of the racquet according to the spacing of the strings, the racquet string straightening device comprising a support and an array of teeth fixedly projecting from the support, each tooth being shaped so as to be capable of being closely received within a respective opening in the array of openings between the racquet strings, the array of teeth comprising a series ot parallel longitudinal rows of teeth which intersects with a series of parallel transverse rows of the teeth, with every tooth in each longitudinal row having the same width and adjacent longitudinal rows being spaced apart at or adjacent the support substantially by the diameter of the racquet strings and with every tooth in each transverse row having the same width and adjacent transverse rows being spaced apart at or adjacent the support substantially by the diameter of the racquet strings, the widths of the longitudinal and transverse rows of teeth varying according to a predetermined arrangement so as to allow for the teeth being closely received within the respective openings, and wherein the teeth in each longitudinal and transverse row are spaced apart so as to be received in every other opening of a corresponding row of the openings between the racquet strings whereby the array of teeth on the support has a checker board appearance.

In use, the head of a racquet is pressed into the device such that the array of teeth, or part of the array, projects through respective openings between the strings of the racquet. The teeth guide the respective portions of the adjacent strings to their correct position within the array of strings.

WO 89/06994 PCT/AU89/00027 7 By omitting every other tooth in each row so that the teeth in adjacent rows alternate, the device is able to straighten all of the strings in the area of the racquet head covered by the device yet frictional engagement with the strings is very substantially reduced as compared to an arrangement in which all of the overlapped openings are engaged by corresponding teeth.

Conveniently, the outer ends of the teeth remote from the support are shaped to facilitate entry of the teeth into the openings. The individual teeth may be tapered from the outer end to a broader base, which base will generally have a cross-section corresponding to the associated opening in the array of strings. Thus the base may be square or rectangular, or it may be oval or circular providing respective diameters correspond to the dimension of the associated opening. Alternatively a body portion of each tooth may be of constant cross-section, for example, sQuare, rectangular, oval or circular as proposed above, in which case the outer end thereof may taper from the body portion to facilitate entry into the associated opening in the array of strings when one or more of the strings is substantially displaced. The join between the constant cross-section body portion and the tapered outer end may be advantageously rounded or smoothed so as to facilitate displacement of the strings over the join. The teeth may be solid or hollow and in the latter instance may have one or more surface portions omitted, for example one or more of the sides or parts of the sides.

-I WO 89/06994 PCT/AU89/000 27 8 The array or strings of the racquet head will generally be orthogonal, but may define diamond or other shaped openings.

As noted alLeady, the openings in the array of strings of most racquets tend to vary in shape and size across the head and the fixed array of teeth should be disposed relative to each other and be shaped to suit the particular array of strings of the racquet for which the device is intended, In some racquets, the openings between strings close to the frame may have an oblong cross-section while those between strings at the centre of the array may be square, but more commonly the variations in size and shape of the openings is irregular. The size, shape and position relative to each other of the teeth may also vary for different kinds of racquets such as for tennis or squash, or for racquets having different stringing methods and patterns. However in most racquets having an orthogonal stringing arrangement, a cernteal longitudinal row of openings between the strings is provided with an equal number of openings to either side and a central transverse row of openings is provided with an equal number of openings to either side, and preferably the teeth of the aligning device are similarly arranged although generally with fewer rows. Furthermore in some racquets having a central longitudinal row of openings, each pair of longitudinal rows of openings spaced by the same number of rows from the central longitudinal row but on respective sides of the latter have the same width, and preferably the longitudinal rows of teeth of the aligning device are correspondingly arranged.

WO 89/06994 PCT/AU89/0002 7 9 The fixed array of teeth will generally extend over an area somewhat smaller than the area of the head of the racquet for which the device is adapted. The array of teeth may be rectangular, oval or, for example, circular, and preferably covers a sufficient area of the racquet head for which it is designed to straighten the strings in at least the "sweet spot".

Most advantageously, the teeth of the array project from the support perpendicular to a single plane. Thus, the support may be planar and the single plane is defined by the principal plane of the support, Alternatively the support may define a curved surface, for example arcuate, about one or more axes, and each tooth projects substantially perpendicularly from the associated portion of the support surface. This embodiment will typically be used by inserting the teeth at one edge of the device into openings at a corresponding portion of the array of strings and rolling the device so that the remaining teeth are successively inserted into respective openings between the strings as the previously inserted teeth are withdrawn.

The device of the present invention may be provided with a handle or other gripping means, preferably on the opposite side of the support to the array of teeth, to aid in its manipulation.

Alternatively the device may be mounted on a structure such as a post or wall.

WO 89/06994 PCT/AU89/00 0 27 One embodiment of a racquet string straightening device in accordance with the present invention will now be described by way of example only with reference to the accompanying drawings in which: FIGURE 1 is a plan view of the embodiment showing the array of alternating teeth; FIGURE 2 is a side view of the embodiment of Figure 1; FIGURE 3 is an end view of the embodiment of Figure 1; FIGURE 4 is a perspective view of a portion of the embodiment of Figure 1; and FIGURES 5 to 9 are schematic representations of various mid-size tennis racquet heads illustrating the variation in size and shape of the openings between the strings.

Referring to Figures 1 to 4, the racquet string straightening device 10 comprises a support 12 having a planar front face 13 from which projects a fixed array of teeth 14 which defines a plurality of intersecting parallel longitudinal rows 16 of the teeth and parallel transverse rows 18 of the teeth with adjacent parallel rows being spaced at or adjacent the support by approximately the cross-section of a racquet string.

The front face 13 oO support 12 defines a planar octagon having opposed longitudinal sides 22, opposed transverse sides 24 and four diagonal 26 extending between the sides 22 and 24, and thus approximates the oval shape of a tennis racquet head.

WO 89/06994 PCT/AU89/00027 11 The teeth 14 each have pairs 27 and 28 of parallel sides so as to define a body portion of rectangular cross-section, and have an outer end remote from the support 12. Each outer end 30 is substantially in the shape of a curved pyramid so that each tooth tapers to a point 32 in order to facilitate entry of the teeth into the respective openings in the array of strings, particularly where the strings are severely displaced. The join between the outer end 30 and the constant cross-section body portion is smoothed or rounded off rather than a sharp delineation.

Every tooth 14 in each longitudinal row 16 has the same width and every tooth 14 in each transverse row 18 has the same width but the various rows tend to have different widths from each other.

This arrangement enables straight strings of the racquet head to extend alongside the teeth between adjacent rows but allows for the variation in size of the openings between the racquet atrings as is described in greater detail with reference to Figures to 9. One arrangement for the variation in size of the teeth 14 is represented in the drawings, particularly in Figure 1 where the irregularity of the widths of the various rows is clearly shown.

The array of teeth 14 in the longitudinal and transverse rows 16 and 18 is such that effectively every other tooth in each row is omitted whereby the array has a checkerboard appearance because adjacent rows alternate as to which tooth is omitted, and the teeth Angage every other opening in

I

substantially less than the width of any tooth in the adjacent longitudinal rows but sufficient to be capable of receiving a respective string of the racquet in straight manner therebetween and with /2 WO 89/06994 PCT/AU89/00027' 12 a strung racquet which is overlaid by the device. In other words adjacent teeth 14 in a longitudinal row 16 are spaced apart by a distance substantially comprising the sum of the width of the transverse row 18 which intersects that longitudinal row between those adjacent teeth and the spacing of that transverse row from the two adjacent transverse rows of teeth. Similarly, adjacent teeth 14 in a transverse row 18 are spaced apart by a distance substantially comprising the sum of the width of the longitidinal row 16 which intersects that transverse row between those adjacent teeth and the spacing of that longitudinal row from the two adjacent longitudinal rows of teeth. The advantage of this arrangement is that the device is equally as effective at straightening the strings as if no teeth were omitted from the array, but because of the reduced contact with the strings the device is very much easier to insert into and remove from the openings in the racquet head.

In most racquets there is a central longitudinal row of openings between the strings, extending from the top of the racquet to the handle, and a central transverse row, and the device 10 is provided with a central longitudinal row 16 of teeth with an equal number of longitudinal rows to either side and a contral transverse row 18 of teeth with an equal number of transverse rows to either side, As illustrated in Figure 1 there are six longitudinal rows to either side of the central longitudinal row and seven transverse rows to either side of the central transverte row.

I

WO 89/06994 PCT/AU89/00027 13 It is also comTnon for the longitudinal rows of openings in a racquet to be arranged in pairs to respective sides of the central longitudinal row, so that each pair of longitudinal rows of openings spaced by the same number of rows of openings from the central longitudinal row but on respective sides of the latter have the same width, and the device is arranged to have corresponding paired longitudinal rows 16 of teeth of the same width equally spaced on respective sides of the central longitudinal row 16.

As can be seen in Figures 2 and 3, a handle is provided on the side of the device 10 remote from the front face 13 to facilitate use of the device. The handle extends the full width of the support 12 and is undercut to ease gripping.

The device 10 is preferably formed by injection moulding in suitable thermoplastics material and may be solid. Alternatively, the support and/or teeth may be hollow. Clearly, the device 10 may be formed in other suitable material such as wood.

In use, a head of a racquet (not shown) and a corresponding device 10 are relatively pressed onto each other with the longitudinal rows 16 parallel to the handle of the racquet. The outer ends 30 of the teeth 14 are received in respective openings between the strings of the racquet notwithstanding that the strings may be displaced. As the correspondingly sized teeth are pressed further through the openings between the strings, the tapered outer ends 30 guide the strings until they are straightened to a regular of teeth (14) projects. The teeth (14) are arranged in longitudinal lows (16) and intersecting transverse rows (18) witd passages between adjacent rows sized to receive the strings of a rnequet. Alternate teeth (14) in each row are omitted from each row in offset manner so that the teeth engage every other opening between the strings of the racquet. Every tooth in each longitudinal row (16) and every tooth in every transverse row (18) has the same width but the widths of the various rows vary according to a predetermined spacing of the strings of the racquet. Preferably there is a central longitudinal row (16) and paired rows (16) on respective sides of the central row and spaced by the same number of rows from the central row have the same width.

WO 89/06994 PCT/AU89/00027 14 orthogonal array and the body portions of the teeth are closely received in the respective openings. The device is then withdrawn aud the racquet is ready for use.

Figures 5 to 9 schematically represent various mid-size tennis racquet heads and illustrate the variation in width of the longitudinal and transverse rows of openings between the strings. All measurements are in millimetres. The strings are represented by straight lines extending at best part way across the head. Not all of the strings are shown. The top of the racquet head is represented by the letter Z (the handle extends from the opposite end). While the centre of the head is represented by the letter X. It may be seen that in all of the illustrated embodiments of racquet head, there is a central longitudinal row extending from the top toward the handle with the widths of the longitudinal rows being paired to either side of the central row.

Figure 5 represents a Dunlop Max 200G racquet (Trade Mark); Figure 6 represents a Pro-Kennex Red-Pro, Blue Pro or Lite Ace racquet (Trade Mark); Figure 7 represents a Wilson Ultra Plus (tapered beam) Kevlar or graphite racquet (Trade Mark); Figure 8 represents a Prince Graphite Pro, Response, Magnesium or Spectrum racquet (Trade Mark); and Figure 9 represents a Head Elite Pro, Prestige Pro, Graphite Pro, Comp Pro, Electra Pro or Leconte Evolution 3 racquet (Trade Mark).

It may be seen, for example, that the irregular variation in width of the longitudinal rows WO 89/06994 PCT/AU89/00027 of openings in the Dunlop (Trade Mark) mid-size tennis racquet in Figure 5 is from 7.2 rm to 11.5 mm and is very much greater than for the Pro-Kennex (Trade Mark) racquet represented in Figure 6. The teeth 14 of the device 10 for each of the illustrated racquets would be substantially correspondingly sized so as to be a relatively close fit in the respective openings.

It will be appreciated that many modifications and variations may be made to the described embodiments and all such modifications and variations should be construed as within the scope of the present invention.

Claims (14)

1. A racquet string straightening device comprising a support and an array of teeth fixedly projecting from the support, each tooth having an outer end and a portion supporting the outer end from the support and, being shaped so as to be capable of being closely received within a respective opening defined in an array of strings of a racquet, the array of teeth comprising a series of parallel longitudinal rows of the teeth which intersects with a series of parallel transverse rows of the teeth, with every tooth in each longitudinal row having the same width and adjacent longitudinal rows being spaced apart at or adjacent the support by a distance substantially less than the width of any tooth in the adjacent longitudinal rows but sufficient to be capable of receiving a respective string of the racquet in straight manner therebetween and with every tooth in each transverse row having the same width and adjacent transverse rows being spaced apart at or adjacent the support by a distance substantially less than the width of any tooth in the adjacent transverse rows but sufficient to be capable of receiving a respective string of the racquet in straight manne. therebetween, the widths of the longitudinal an transverse rows of teeth varying according to a predetermined arrangement so as to allow for the teeth bGing closely received within the respective openings, and wherein adjacent teeth in each longitudinal row are spaced apart at or adjacent the support by a distance substantially comprising the sum of the width of a respective intersecting transverse row and the spacing of that transverse row string of the racquet in straight manner therebetween VO 89/06994 PCT/AU89/00027 17 from the two immediately adjacent transverse rows of teeth and adjacent teeth in each transverse row are spaced apart at or adjacent the support by a distance substantially comprising the sum of the width of a respective intersecting longitudinal row and the spacing of that longitudinal row from the two immediately adjacent longitudinal rows of teeth whereby the array of teeth has a checker board appearance.

2. A device according to claim 1 wherein the outer end of each tooth is shaped to facilitate entry of the tooth into the respective opening o4 the array of strings.

3. A device according to claim 2 wherein the outer end of each tooth is tapered.

4. A device according to claim 2 wherein each tooth has a body portion between the outer end and the support, said body portion having a profila of substantially constant cross-section.

A device according to claim 4 wherein the body portion has a rectangular cross-section.

6. A device according to claim 4 wherein the boundary between the body portion and the outer end is rounded.

7. A device according to claim 1 wherein the support has a front face from which the teeth project which is planar. u iA= OIL CL .Oia U. openings between the strings which openings vary in WO 89/06994 PCT/AU89/00027 18

8. A device according to claim 1 wherein each tooth projects perpendicularly from the support.

9. A device according to claim 1 which is provided with a handle.

A device according to claim 9 wherein the handle extends from the side of the support opposite to the teeth.

11. A device according to claim 1 which has a central longitudinal row of teeth with aa equal number of longitudinal rows of teeth to either side thereof and a central transverse row of teeth with an equal number of transverse rows of teeth to either side thereof.

12. A device according to claim 1 which has a central longitudinal row of teeth with an eqnial number of longitudinal rows of teeth to either side thereof, and wherein each pair of longitudinal rows spaced by the same number of rows of teeth from the central longitudinal row but on respective sides of the latter have the same width.

13. In combination, a strung racquet and a racquet string straightening device therefor, said racquet having a head and a plurality of strings supported thereby, said strings being arranged in a series of substantially parallel main strings and a series of substantially parallel cross strings generally transverse to said main strings to define an array of openings between the strings whAch openings vary in size and shape across the head of i *W A. i-n: auja~cnut strings to their correct position within the array of strings. -19- the racquet according to the spacing of the strings, the racquet string straightening device comprising a support and an array of teeth fixedly projecting from the support, each tooth being shaped so as to be capable of being closely received within a respective opening in the array of openings between the'racquet strings, the array of teeth comprising a series of parallel longitudinal rows of teeth which intersects with a series of parallel transverse rows of the teeth, with every tooth in each longitudinal row having the same width and adjacent longitudinal rows being spaced apart at or adjacent the support substantially by the diameter of the racquet strings and with every tooth in each transverse row having the same width and adjacent transverse rows being spaced apart at or adjacent the support substantially by the diameter of the racquet strings, the widths of the longitudinal and transverse rows of teeth varying according to a predetermined arrangement so as to allow for the teeth being closely received within the o respective openings, and wherein the teeth in each longitudinal and transverse row are spaced apart so as to be received in every other opening of a corresponding row of the openings between the racquet strings whereby the array of teeth on hie support has a checker board appearance. *0

14. A racquet string straightening device substantially as herein described with reference to the accompanying drawings. DATED this 20th day of February, 1991. VACLAV UBL By his Patent Attorneys DAVIES COLLISON 910,PHHDAT063t1ub, 1e 1 19