GB2096473A

GB2096473A - Shuttlecocks

Info

Publication number: GB2096473A
Application number: GB8209458A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-04-15
Filing date: 1982-03-31
Publication date: 1982-10-20
Also published as: DK173581A; GB2096473B; JPS57177782A

Abstract

An artificial feather for shuttlecocks comprises a stem (4) and a vane composed of two separate vane portions (2, 3) made of a foamed plastics material. These three components are interconnected by means of two longitudinally extending adhesive strips (11), one on each of the opposed surfaces of the vane. In an area adjoining the tip (8) of the feather the adhesive strips protrude beyond the front edges (12, 13) of the vane portions and beyond the end face (7) of the stem, and in this area the adhesive strips are connected directly with one another in superposed relationship, whereby they form part of the vane (1). There is obtained an increase in the ability of the feather to resist the impact loads to which it is exposed, and thus an increase of the life of the shuttlecock. <IMAGE>

Description

SPECIFICATION An artificial feather for shuttlecocks This invention relates to an artificial feather for shuttlecocks, comprising a stem and a vane composed of two separate vane portions made of foamed plastics sheet and extending outwardly from opposite side edges of the stem.

Danish patent specification No. 142,804 discloses an artificial feather of this kind, wherein the two vane portions are glued directly to the stem.

The present invention provides an artificial feather of the kind referred to initially, in which the vane, ratherthan being glued to the stem as described in the quoted Danish patent specification, is secured to the stem by means of two adhesive strips, which extend longitudinally of the feather on opposite faces thereof in overlapping relation with the stem and the adjoining longitudinal zones of the vane portions, and which at the tip of the feather protrude beyond both vane portions and the front end face of the stem, the protruding portions of said adhesive strips being directly connected to one another in superposed relationship.

It has been found that compared with the known feather mentioned above a feather according to the present invention is far better capable of absorbing the considerable forces exerted on the feather during the use of a shuttlecock, and this results in a considerably longer life of the feather and thus of the shuttlecock. This is believed to be due to the fact that with strips made of commercially available adhesive tapes it is possible to obtain a very strong bonding of the strips to the vane portions and to the stem and thus, indirectly, a bond between the vane and the stem which is superior to that obtained when the vane and the stem are glued together.In this connection it is of special importance that the two adhesive strips overlap and are directly connected in an area at the tip or front end of the feather and that the adhesive strips, as a consequence of being bonded together in that area, constitute the vane tip proper, where the feather is exposed to maximum bending when it is struck by a racket. It has been found that a feather of similar design, but in which the vane portions of foamed plastics extend to the very tip of the feather, is destroyed quite rapidly because the tip of the feather splits longitudinally through the vane material, presumably because the bond between the foamed plastics and the adhesive tape is stronger than the inner cohesion of the plastics material.

It is pointed out that Danish patent specification No. 142,804 also discloses an artificial feather, the vane of which is secured to the stem by means of a single adhesive strip, which extends along the entire length of the vane on one face thereof, and which at the free end of the feather is folded back and secured to the rear face of the vane along part of the vane length. This design requires that the vane is made in one integral piece and that its front end is formed as a straight line perpendicular to the stem.The first condition excludes the possibility of making the vane from two pieces of foamed plastics each oriented at an acute angle to the stem, which has been found to be important for the quality of the feather, and the second condition is incompatible with the wish that in respect of properties and appearance the feather shall be as close to a natural feather as possible.

Each vane portion may be defined, at its forward end, by an inclined edge oriented at a forwardly diverging acute angle with the stem. It is thus obtained that the tip area, in which the adhesive strips are directly jointed, increases gradually in width from the rear towards the contour of the vane, and thus merges evenly into the thicker vane portions behind the tip area. The embodiment is espe cial ly suitable for feathers, whose vane portions are made from longitudinally oriented foamed plastics sheets each of which abuts on a side edge of the stem at the said acute angle.

The foremost point of the inclined edge of each vane portion may be located closely inward of the adjacent longitudinal edge of an adhesive strip. This feature ensures a maximum overlapping area of the adhesive strips at the tip of the feather.

In this embodiment the front end face of the stem is preferably located in front of the rearmost point of the inclined edge of each vane portion and behind the forwardly oriented contour of the area in which the adhesive strips are directly connected. Thus the stem contributesto increasing the bending stiffness, and consequently the stability, of the highly stressed vane tip, while at the same time the risk that in response to being repeatedly bent forth and back the end of the stem breaks through the surface of the tip area.

The two adhesive strips may extend rearwardly behind the rearmost points of the vane portions, at least to that point of the feather which, when the feather is mounted in the cap or nose of a shuttlecock, engages the upper face of the cap. Behind the vane the connected adhesive strips thus form an envelope which totally encloses the stem and which comprises two flanges or flaps protruding laterally beyond the side edges of the stem, thus increasing the bending stiffness of the stem.

In the edges of the flanges there may be provided incisions for accommodating strings, which in a completed shuttlecock encircle all feathers. Thisfea- ture ensures a purely mechanical fixation of said strings, which are thus prevented from sliding downwards along the stem towards the cap of the shuttlecock in case their traditional fixation to the stem by glueing should fail after the shuttlecock has been in use for a certain time.

The invention will be described in more detail below with reference to the accompanying, somewhat schematical drawing, in which Fig. lisa plan view of one embodiment of an artificial feather according to the invention, Fig. 2 is a plan view on a larger scale of the tip of the feather, Figs. 3-5 are sections on a still larger scale along the lines Ill-Ill, IV-IV and V-V, respectively, of Fig. 2, and Fig. 6 is a plan view, corresponding to Fig. 2, of a slightly modified embodiment.

The feather shown in Figs. 1-5 comprises a vane 1, consisting of two separate vane portions 2 and 3 which extend outwardly from opposite side edges of the feather stem 4. The vane portions 2 and 3 are made from foamed plastics sheet, for example polypropylene sheet with a density of approx. 0.6, and the material of each vane portion is oriented in a direction which includes an acute angle of approx.

45 with the longitudinal direction of the stem. Due to the directional orientation of the vane material it is possible, afterthe vane portions have been secured to the stem, to split or slit each vane portion in the direction of orientation, which in Fig. 1 is shown by means of slits 5 extending from the contour of vane portion 2. For the sake of clarity, the slits, which extend through the whole thickness of the vane and which are preferably also provided in the entire vane area, have been shown only in a smaller part of the area. The silts may be effected in various lengths, so that the lengths of the tongues defined between successive slits are correspondingly different, and if desired the spacing of the slits may also vary, e.g.

such that the tongues are narrower at the tip of the featherthan further down the vane.

The feather stem 4 has a rectangular cross-section of constant width through its entire length, and preferably its height decreases evenly from the end face 6 of the stem at that end of the feather which is to be inserted into the cap or nose of the shuttlecock, to the end face 7 adjacent the feather tip 8. The stem may consist of a matrix of a plastics material, for example epoxy plastics, reinforced by means of longitudinally extending filaments, especially carbon filaments, which give the stem high bending strength. The stem may be punched from a pultru dated rod or slab. The stem may have a width of approx. 0.75 mm and a height which decreases from approx. 1.2 mm at the end face 6 to approx. 0.4 mm at the opposite end face 7.

As is best shown in Fig. 3 each vane portion 2 and 3 adjoins a side edge of the stem 4 with one surface of the vane portion being flush with one transverse face 9 of the stem, primarily that face which after insertion of the feather into a shuttlecock is facing inwards towards the centre line of the shuttlecock.

The vane portions are secured to the stem by means of two adhesive strips 10 and 11, of which strip 10 overlaps face 9 of the stem and the adjoining longitudinal edge zones of both vane portions 2 and 3, while strip 11 is folded around the face of stem 4 opposite to face 9 and around the two side edges of the stem. From each side edge strip 11 extends in overlapping relation with the adjoining edge zone of the other surface of each vane portion. For the sake of clarity, both the vane portions 2 and 3 and the adhesive strips 10 and 11 have been shown in Figs.

3-5 with their thickness exaggerated in relation to the dimensions of stem 4.

The front edge 12 and 13, respectively, of each vane portion 2 and 3 is retracted in relation to the feather tip 8, whereby an area 14, which in Fig. 2 is shown double-hatched, is formed between said edges and the contour of vane 1. In area 14 the adhesive strips 10 and 11 are superposed and are con nected directly with one another, see also Figs. 4 and 5. In Fig. 2, the area 14 is shown of the maximum size obtainable in practice, in that the edges 12 and 13 of the two vane portions intersect the vane contour immediately inwardly of the respective longitudinal edge of adhesive strip 11. When the edges 12 and 13 are retracted as much as shown in Fig. 2, it is expedient to let the end of stem 4 extend for some distance into area 14.

In the embodiment shown in Fig. 6, where corresponding parts are designated by the same reference numerals as in Fig. 2, supplemented by an index, area 14', in which the adhesive strips overlap directly, is somewhat smallerthan area 14, as the edges 12' and 13' adjoin the end face 7' of stem 4'.

Irrespective of the location of the front edges of the vane portions, the front end face 7 or 7' of stem should be located slightly behind the tip 8 or 8' of the feather, as also shown in Figs. 2 and 6.

As mentioned above and as shown in Fig. 1, both adhesive strips 10 and 11 are prolonged rearwardly from vane 1 to the rear end face 6 of the stem. In a region behind vane 1 the adhesive strips are connected to one another on both sides of stem 4, so that they form an envelope, which completely encloses the stem, and which along face 9 has two protruding, longitudinal flanges or flaps 15 and 16 which increase the bending stiffness of the stem. In the edges of the flaps there are two pairs of opposed incisions 17 and 18 which, afterthe required number of feathers have been inserted in the cap of a shuttlecock, serve for the axial fixation of strings which are crocheted around the feather stems for the purpose of keeping the feathers together in the peripheral direction.The two incisions 17 are located immediate behind the rear end of the vane area while the two other incisions 18 are located between the vane and two shoulders 19, which serve for the axial location of the feather relative to the cap or nose of the shuttlecdck.

For producing the feather the following procedure may be employed: The adhesive strip 10 is placed on a suitable base and the stem 4 is placed on top of the adhesive strip. Then two longitudinally oriented sheets 20 and 21 of foamed plastics (see Fig. 1), whose end edges include an angle of approx. 45' with the longitudinal direction of each sheet, are placed on top of strip 10 with said end edges abutting on the stem 4's side edges. The front and rear longitudinal edges of each sheet have been shown at 22 and 23, respectively. Then the adhesive strip 11 is placed on top of the stem and the foamed plastics sheets, and all components of the feather are joined in a suitable press tool. Finally, the feather contour, including the contours of flanges 15 and 16, may be shaped by a punching operation.

For the production of feathers according to this invention good results have been obtained by using, for the matrix of the reinforced feather stem, an epoxy plastics consisting of the following components: LY556, HY918 (hardener), and DY 070 (accelerator), all supplied by CIBA-GEIGY, with a slip agent CELEC, type U, supplied by Dupont. A suitable adhesive strip is the polyester tape supplied by 3M under the trade name 352 for packaging and wrapping processes, and which includes a rubber-based adhesive substance on a polyester film.

Claims

1. An artificial feather for shuttlecocks, comprising a stem and a vane composed of two separate vane portions made of foamed plastics sheet and extending outwardly from opposite side edges of the stem, wherein the vane is secured to the stem by means of two adhesive strips which extend longitudfinally of the feather on opposite faces thereof in overlapping relation with the stem and the adjoining longitudinal zones of the vane portions, and which at the tip of the feather protrude beyond both vane portions and the front end face of the stem, the protruding portions of said adhesive strips being directly connected to one another in superposed relationship.

2. An artificial feather is claimed in claim 1, wherein each vane portion is defined, at its forward end, by an inclined edge oriented at a forwardly diverging acute angle with the stem.

3. An artificial feather as claimed in claim 2, wherein said acute angle is approx. 45".

4. An artificial feather as claimed in claim 2 or3, wherein the foremost point of the inclined edge of each vane portion is located closely inward of the adjacent longitudinal edge of an adhesive strip.

5. An artificial feather as claimed in claim 4, wherein the front end face of the stem is located in front of the rearmost point of the inclined edge of each vane portion and behind the forwardly oriented contour of the area in which the adhesive strips are directly connected.

6. An artificial feather as claimed in claim 1, in which each adhesive strip extends rearwardly behind the rearmost points of the vane portions at least to that point of the feather which, when the feather is mounted in the cap of a shuttlecock, engages the upper face of the cap.

7. An artificial feather as claimed in claim 6, in which incisions for accommodating strings which in a completed shuttlecock encircle all feathers thereof, are provided in the edges of the flanges formed by the connected adhesive strips and protruding laterally beyond the width of the stem.

8. An artificial feather for shuttlecocks, substantially as hereinbefore descirebed and shown in Figs.

1 5 or in Fig. 6 of the accompanying drawing.