The present invention relates to the field of accessories for playing table tennis. More particularly, it relates to a table-tennis net assembly comprising a net proper and two supports for said net, each fitted with means for fastening to a respective side of the table. The invention relates particularly but not exclusively to a set in which at least one of the supports is fitted with an automatic net winder.
Integrating an automatic net winder in at least one of the supports of a table-tennis net assembly is known from U.S. Pat. No. 4,850,590. In that document, the net support is constituted by a cylindrical tube having a vertical pivot shaft mounted therein, with its bottom end passing through a chamber in which a spiral torsion spring is housed that is wound around said shaft. One end of the spiral-spring blade is secured to the pivot shaft while the other end is secured to the chamber. The net is mounted on the pivot shaft in such a manner that the spiral torsion spring contributes to tensioning the net when the two supports are mounted on opposite sides of the table, and serves automatically to wind in the net around the shaft inside the cylindrical tube when the net is removed from the table.
Advantageous though it might be, the winder device of U.S. Pat. No. 4,850,590 nevertheless presents drawbacks. From a manufacturing point of view, it is not easy to mount the spiral spring, and above all to adjust it so as to obtain good conditions for tensioning the net and for winding it in automatically. The spring can be damaged if the assembly is not kept under good storage conditions between two utilizations. The author of U.S. Pat. No. 4,850,590 was well aware of this difficulty since a knob is provided for turning the pivot shaft in the event of the spring blade malfunctioning.
One of the objects of the present invention is to propose a table-tennis net assembly with a winder that mitigates the above-mentioned drawbacks.
Concerning the means for fastening the support to the sides of the table, they are generally of the clamp type, with a top jaw that is to bear against the top face of the side of the table and a bottom jaw or equivalent element that is designed to bear against the bottom face of the side of the table, together with means for driving the two said jaws in displacement relative to each other. For example, the bottom jaw can be mounted on a threaded rod, which, on being turned, causes the bottom jaw to move vertically relative to a stationary horizontal support secured to the top jaw. That type of fastener means is awkward for a user to actuate, since the user needs to turn the threaded rod about its own axis and there is a danger of spoiling the bottom face of the table if excessive pressure is applied.
One of the objects of the present invention is to propose a table-tennis net assembly with means for fastening to the sides of the table that mitigate the above-mentioned drawbacks.
This object is fully achieved by the table-tennis net assembly that comprises a net and two net supports, each support having a structure including fastener means for fastening the support on a side of a table, and at least one of the net supports including, for winding the net, a hollow winder spool.
In a manner characteristic of the invention, the net assembly includes an elongate resilient element mounted inside said spool, having a first end secured to the winder spool and a second end secured to the structure of the support, said resilient element forming part of the means for actuating the winder spool and/or of means for actuating the fastener means.
Preferably, the elongate resilient element is made of natural or synthetic rubber, is of circular or square section, e.g. is made of natural rubber and is of circular section having a diameter of about 8 millimeters (mm) to 12 mm.
In a variant embodiment, the first end of the resilient element is fastened to the top portion of the winder spool via a cover-forming central part that is engaged axially in said top portion of the spool. Thus, while the net assembly is being assembled, it is possible to stretch the resilient element, to fasten it to the central part, and to engage said part in the top portion of the spool.
Preferably, the cover includes a radial slot forming an opening passing right through the thickness of the cover, with the first end of the resilient element being inserted and jammed in said opening.
When the resilient element forms a part of the actuator means of the winder spool, said spool is pivotally mounted and it is the twisted elongate resilient element that serves to deliver the energy needed for tensioning and automatically winding the net around the spool.
In a variant embodiment, the bottom end of the winder spool includes an annular cheekplate terminated by a cylindrical rim, with the support structure comprising a stationary plate having a hollow cylindrical housing formed in its thickness suitable for receiving said cylindrical rim together with an annular bearing disposed in the cylindrical housing under the cheekplate. The annular bearing constitutes means that are preferred, amongst others, for limiting friction between the winder spool and the structure of the support when the winder spool is set into rotation under drive from the resilient element.
In a variant embodiment, the fastener means of the table-tennis net assembly are of the clamp type, with a top jaw for bearing against the top face of the side of the table and a bottom jaw for being brought to bear against the bottom face of the side of the table, together with means that can be actuated to move said two jaws relative to each other. The top jaw is preferably integrated in the structure of the support, and in particular it may be constituted by a portion of the above-mentioned stationary plate.
In U.S. Pat. No. 4,850,950, where the fastener means are likewise of the clamp type, the means that can be actuated to move the two jaws comprise a spiral traction spring placed so as to move the bottom jaw towards the top jaw.
When the resilient element forms part of the means that can be actuated to move the two jaws relative to each other, the second end of said elongate resilient element is secured to the bottom jaw. Thus, the resilient element performs the function of moving the two jaws towards each other. As mentioned above, it can also perform the function of winding the net if the winder spool is also pivotally mounted. This function of moving the two jaws towards each other and of driving the winding of the net are performed by two distinct and independent springs in U.S. Pat. No. 4,850,590.
Preferably, the bottom and top jaws are displaced in vertical translation and the means that can be actuated to move them likewise comprise a vertical hollow tube secured to the bottom jaw, passing through the top jaw, and slidably mounted inside the winder spool. In addition, the elongate resilient element passes inside said hollow tube. It is this resilient element with its two ends secured respectively to the top portion of the spool and to the bottom jaw that holds together the assembly of parts that can be moved either in translation or optionally in rotation.
In U.S. Pat. No. 4,850,590, the bottom jaw of the clamp for fastening onto the side of the table is provided with a kind of handle that is to be found under said jaw. Thus, in order to mount the support, the user needs to hold the cylindrical tube containing the net in one hand and use the other hand to take hold of said handle in order to fasten the net assembly to the side of the table, after opening the clamp by moving the bottom jaw away using the handle.
In a variant embodiment of the present invention, the bottom jaw includes a vertical actuator arm passing through a portion of the stationary plate that is on the side of the winder spool opposite from the portion of said plate that acts as the top jaw. Thus, in this particular configuration, only one hand is needed to open the clamp in order to place the support on the side of the table, as explained in greater detail below.
In a preferred embodiment of the invention, each of the two net supports includes a respective winding guide constituted by two vertical rods secured to the top of the top jaw close to the winder spool.
The present invention can be better understood on reading the following description both of a preferred first embodiment of a table-tennis net assembly with a winder in which each of the two net supports includes a resilient element serving both to perform the winding function and the function of actuating the system for securing the support to the side of the table, and of a simplified second embodiment in which the resilient member serves solely to perform the function of actuating the fastener system, as shown in the accompanying drawings, in which:
In the first embodiment, the table-tennis net assembly 1 as shown in
With reference to
a winder spool 6;
a stationary plate 7, part of which acts as the top jaw 4;
a moving part 8, part of which acts as the bottom jaw 5;
a hollow guide tube 9;
a resilient element 10; and
a bearing 11.
The winder spool 6 for the net 2 is a hollow spool, with the hollow tube 9 being housed therein and with the resilient element 10 being housed inside the tube extending along a direction corresponding to the axis DD′ which is a vertical axis when the support 3 is mounted on the side of a table with the table top being horizontal. The top and bottom portions 6a and 6b of the spool 6 comprise respective cheekplates, namely a top cheekplate 12 and a bottom cheekplate 13 which are spaced apart by a distance that is slightly greater than the height of the net. In the storage position, the wound-up net is located between the two cheekplates 12 and 13 as can be seen in
In the top portion 6a of the spool, there is provided a housing 14 having a cover 15 closing said top portion 6a of the spool 6, but serving mainly to enable the resilient element 10 to be secured to the top portion 6a of the spool 6. The cover 15 has a radial slot 16 into which the resilient element 10 is inserted after being stretched sufficiently to reduce its diameter. In the relaxed state, the resilient element 10 is held securely in the slot 16 of the cover 15. The cover 15 is held in the top portion 6a of the spool 6 via an internal shoulder 17 that is pierced by a through hole 18 through which the resilient member 10 can pass.
The bottom cheekplate 13 of the winder spool 6 has a cylindrical outer rim 19. In its thickness, the stationary plate 7 presents an annular housing 20 of dimensions suitable for receiving the winder spool 6, and more precisely for receiving the cylindrical rim 19 of the bottom cheekplate 13 of said spool 6.
Between the bottom cheekplate 13 and the bottom 20a of the housing 20 there is disposed a bearing 11 constituted by a plate 21 of annular configuration having a plurality of balls 22 inserted therein, the diameter of the balls being greater than the thickness of the plate 21.
As shown in
The stationary plate 7 is pierced by a through hole 23 suitable for passing the hollow tube 9. Preferably, said hollow tube 9 is square in section and the through hole 23 is likewise square in section so that the tube 9 is capable solely of sliding vertically through the though hole 23. Provision is made for the stationary plate 7 to include a downward extension 24 of square section serving as a slideway for guiding the hollow tube 9.
Under the stationary plate 7 on its side corresponding to the top jaw 4, there is secured an elastomer pad 25. This pad is for pressing against the top face of the table.
A through hole 27 is provided through the stationary plate 7 in a position that is remote from its portion that acts as the top jaw 4.
The moving part 8 having a portion that acts as the bottom jaw 5 is secured to the bottom end of the hollow tube 9. Another elastomer pad 26 is secured to the top face of the moving part 8 that acts as the bottom jaw 5. The moving part 8 has an actuator arm 28 located remote from the jaw 5 and shaped to pass through the hole 27 in the stationary plate 7. The bottom end 10b of the resilient element 10 is secured to the moving part 8. In the example shown, this is achieved by means of a pin 29 passing through the moving part 8 and also through the hollow tube 9 and the bottom end of the resilient element 10.
In a particular embodiment, the resilient element 10 is constituted by a solid cylindrical body of natural rubber having a diameter of about one centimeter. It could also be a solid body of square section. This solid body structure has given better results in terms of responsiveness of the net-winding function in comparison with a resilient member in the form of a flat strip or an elastic band.
The net support 3 is put into place by actuating the arm 28 in the direction of arrow F (
Given that the bottom end 10b of the resilient element 10 is secured to the moving part 8, movement in the arm 28 along arrow F is opposed by the force exerted by said element. It is therefore necessary for the user to press down on the arm 28 hard enough to open the jaws 4 and 5 so as to position the support 3 on the side 30; thereafter the user releases the actuator arm 28 and the moving part 8 returns to its initial position because the resilient element 10 tends to return to its initial rest length. In so doing, the support 3 is secured onto the side 3 of the table by the traction force of the resilient element 10.
It should be observed that the hollow tube 9 serves to guide and to stiffen the support 3 while the moving part 8 is moving in translation relative to the stationary plate 7. In this particular embodiment, the hollow tube 9 is a metal tube of square section. Optionally, the moving part 8 and the hollow tube 9 could be made as a single piece by injection molding or by any other molding technique.
In order to actuate the arm 28, the user can take hold of the stationary plate 7 using only three fingers of one hand, the index and middle fingers being disposed under the stationary plate 7 on either side thereof, with the thumb pressing down on the actuator arm 28.
Once the first support 3 has been mounted on the side 30 of the table, the user takes hold of the second support 3′ and goes round the table to mount the second support 3′ on the other side of the table. In so doing, the net 2 which was wound at least in part around the winder spool 6 is unwound, thereby causing the spool 6 to turn about its axis DD′. This turning movement twists the resilient element 10 because the top end 10a of said element 10 is secured to the top portion 6a of the spool 6.
Once the assembly 1 is in position on the table with the net 2 under tension between the two supports 3, 3′, the resilient elements 10 in each of the supports remain in the tensioned state. When the assembly 1 is put away with the two supports 3, 3′ being moved towards each other, the resilient element untwists, thereby naturally causing the spool 6 to turn and thus winding in the net until the resilient element 10 returns to its initial state corresponding to the rest state shown in
The present invention is not limited to the above-described embodiment. For example, the ball bearing could be replaced by using material in the housing that presents a very low coefficient of friction, thus enabling the spool 6 to turn on the stationary plate 7 without excessive friction, in spite of the traction force exerted by the resilient element 10.
In
The two rods in any one set can be united at their top ends so as to form an arch.
As mentioned above, in the above-described preferred first embodiment, the resilient element serves both to turn the hollow spool in order to wind the net, and also to actuate the system for fastening the support to the side of the table. This is not essential. The resilient element could be used to perform only one of these two functions.
In particular, on comparing the embodiment shown in
Number | Date | Country | Kind |
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0502380 | Mar 2005 | FR | national |