The present invention relates to table-tennis net apparatus, and to table-tennis net-supporting device forming part of the apparatus.
The governing body for table-tennis, the International Table Tennis Federation or ITTF, stipulates strict parameters which a table-tennis net assembly to be used with a table-tennis table must adhere to. Consequently, although advancement and innovation is specifically encouraged in the rules, little progress has been made over the years.
With traditional screw-clamp post bodies, the design is very basic, involving an upright post to which the table-tennis net is attached, and a manual tie-off point for a net suspension cord. To attach the body to a table tennis table, a basic screw-threaded clamp is provided.
The deficiencies with the traditional design are that the table-tennis net must be set up and the net cord manually re-tensioned each time it is erected in order to meet ITTF requirements. This involves the use of a heavy tension gauge and manual adjustment of the tie-off of the net cord, and is thus time-consuming.
Furthermore, the height of the net cord above the table-tennis table must be re-set each time. This involves the use of a light net gauge and manual adjustment of the upright post. Again, this is time consuming.
The net cord often slips off the upright post, requiring re-setting and possible re-tensioning.
With the traditional screw-clamp, over tightening is a common issue leading to wear and damage of the net post and table-tennis table.
Additionally, the traditional arrangement typically requires two people to set up the net assembly correctly to fully meet ITTF requirements.
The present invention seeks to overcome all of these problems.
According to a first aspect of the invention, there is provided table-tennis net apparatus comprising two net-supporting devices, a suspension element extending between the two net-supporting devices, and a table-tennis net supportable by the suspension element and attachable to the two net-supporting devices, each net-supporting device including an upright post having an at least substantially hollow tubular cartridge holder and an elongate cartridge receivable in the cartridge holder, the cartridge holder including a longitudinal slot for the net to extend therethrough, the suspension element including a flexible elongate element and a spring element which is engagable with a said cartridge, the net being suspendable from the flexible elongate element, and the flexible elongate element being automatically tensionable by the in use spring element.
Preferable and/or optional features of the first aspect of the invention are set forth in claims 2 to 22, inclusive.
According to a second aspect of the invention, there is provided a table-tennis net-supporting device comprising a clamp body, an upright post having an at least substantially hollow tubular cartridge holder and an elongate cartridge receivable in the cartridge holder, the cartridge holder including a longitudinal slot for a table-tennis net to extend therethrough, a cartridge connector for retaining the cartridge within the cartridge holder, and an adjustable over-centre clamping mechanism for attaching the device to a table-tennis table.
According to a third aspect of the invention, there is provided a method of automatically tensioning a suspension element for a table-tennis net, the method comprising the steps of: a] locating a net-supporting device either side of a table-tennis table; b] providing a suspension element spanning between upright posts of the net-supporting devices, a table-tennis net being suspended from the suspension element; and c] using a spring element in at least one of the upright posts to automatically tension the suspension element.
The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:
Referring to the drawings, there is shown one embodiment of table-tennis net apparatus 10 which comprises a table-tennis net 12, a net-supporting device 14 to hold each end of the table-tennis net 12, and an elongate flexible suspension element 16 from which the table-tennis net 12 is suspendable and which is also engagable with each net-supporting device 14.
Each net-supporting device 14 includes a, preferably plastics moulded or metal, clamp body 18, an adjustable over-centre clamping mechanism 20 at or adjacent to a clamp end 22 of the clamp body 18 for releasably attaching the device 14 to an edge of a table-tennis table, and an upright post 24 at or adjacent to a post end 26 of the clamp body 18 which is opposite the clamp end 22.
The upright post 24 comprises two parts, being a, preferably plastics or metal, elongate cartridge 28 and an at least substantially hollow tubular cartridge holder 30 in which the cartridge 28 is slidably receivable. The cartridge holder 30, which again may beneficially be plastics or metal, is preferably integrally formed or permanently fastened to an upper land 32 of the clamp body 18 at or adjacent to the post end 26.
The cartridge holder 30 has an open upper end 34 and an open lower end 36, along with a linear net slot 38 which extends along at least a majority of a longitudinal extent thereof from the upper end 34. A lateral extent of the net slot 38 is dimensioned to receive the table-tennis net 12 therethrough, and the longitudinal extent is sufficient to receive at least a majority of the height of the table-tennis net 12.
The elongate cartridge 28 comprises a, preferably solid, body 40 having a first elongate recess 42 on one side, a second elongate recess 44 on the other side, a lateral guide slot 46 in its upper end, and a height-adjustment slot 48 at its lower end.
The first elongate recess 42 communicates with the lateral guide slot 46, and opens out partway therealong to receive a spring element 50 of the suspension element 16. An engagement element 52, in this embodiment being a pin or peg, is provided at or adjacent to the closed end of the first elongate recess 42. The engagement element 52 is adapted to engage the spring element 50 at one end. A depth of the first elongate recess 42 is sufficient to fully or substantially fully receive the spring element 50.
The lateral guide slot 46 is dimensioned to receive as a close sliding fit a flexible elongate element 55 of the flexible suspension element 16, which in this case is a net-suspension cord. The guide slot 46 is open at both lateral ends and includes a reduced-width longitudinal opening 54 for captively retaining the flexible elongate element 55 therein. This prevents or limits unintentional disengagement of the flexible elongate element 55 from the cartridge 28 whilst still enabling removal when necessary.
The second elongate recess 44 is, in this case, closed at both lateral ends and is dimensioned to receive a removable locking pin 56. The locking pin 56 is a rigid straight elongate bar, either being plastics, metal or possibly wood, which is slidably receivable in a pocket 58 extending the height of the table-tennis net 12 and formed at each end of the table-tennis net 12.
With the locking pin 56 received in the table-tennis net 12, the table-tennis net 12 and locking pin 56 are located in the second elongate recess 44. With the flexible elongate element 55 received in the lateral guide slot 46 and connected to the upper end of the spring element 50, which in turn is mounted in the first elongate recess 42 and connected to its engagement element 52, the cartridge 28 can be slid into the cartridge holder 30 so that the table-tennis net 12 extends through the net slot 38.
Beneficially, the cartridge 28 may also include a key 60 for preventing or limiting angular displacement of the cartridge 28 within the cartridge holder 30. The net slot 38 therefore also acts as a keyway 62 for slidably receiving the key 60.
Although it is possible to provide each net-supporting device 14 with a spring element 50 to which the flexible elongate element 55 is engaged, the spring element 50 only needs to be provided on one of the net-supporting devices. To this end, to reduce manufacturing costs, each cartridge 28 preferably includes a quick-release tie-off element 64 in or adjacent to the first elongate recess 42.
By way of example,
It may be beneficial that the second aperture 70 is or includes a tapered portion to provide a secondary wedging engagement of the flexible elongate element 55 on its return.
Furthermore, a further set of first and second apertures 66, 70 may be included towards the other end of the first and second elongate recesses 42, 44, again to improve the releasable securement of the flexible elongate element 55.
To simplify engagement of the flexible elongate element 55 with the spring element 50, the end of the flexible elongate element 55 may be looped through a hooked or looped end 72 of the spring element 50 and tie-off to the cartridge 28 via the quick-release tie-off element 64.
To retain the cartridge 28 in the cartridge holder 30, a rotatable-plate cartridge connector 74 is provided adjacent to the lower end of the cartridge holder 30. A lower end of the cartridge 28 includes a hooked tail 76 defining the height-adjustment slot 48. The hooked tail 76 extends from the open lower end 36 of the cartridge holder 30 so that the height-adjustment slot 48 faces outwardly in the direction of the post end 26 of the clamp body 18.
The cartridge connector 74 in this embodiment is a height adjuster 80 for adjusting a longitudinal position of the cartridge 28 in its respective cartridge holder 30 whilst maintaining retention within the cartridge holder 30. As best seen in
The arcuate cam surface 84 is not continuous, thereby allowing a gap 90 for the hooked tail 76 of the cartridge 28 to be received as the cartridge 28 is slid home into the cartridge holder 30.
Advantageously, the dial 82 may include an indicator 92 indicating an amount of longitudinal displacement imparted to the cartridge 28 relative to the cartridge holder 30 as the dial 82 is turned.
The height adjuster 80 may include an indexer to step-wisely adjust height of the cartridge 28. For example, the rotational axis 88 of the dial 82 extends perpendicularly or substantially perpendicularly to the longitudinal extent of the cartridge holder 30. As such, opposing interdigitatable crowns or castellated elements may be provided with spring biased interengagement. The dial 82 may be slightly axially displaced to release the interdigitated interengagement, thereby allowing free rotation. The spring biasing into engagement would prevent or limit unintentional adjustment once set.
The indicator 92 may also include a display area 94 for displaying a logo or other indicia 96. For example, if meeting the ITTF requirements, the ITTF logo may be displayed.
If height-adjustment is not required, then the dial 82 of the connector 74 may be replaced by a simple circular or rectangular rotatable or pivotable plate having a protrusion to releasably engage the hooked tail 76 of the cartridge 28.
The over-centre clamping mechanism 20, as shown in
The clamp body 18 includes a fixed jaw 106 which is opposite the movable clamping jaw 104. The fixed jaw 106 is intended to lie on a top surface of a table-tennis table, and as such may be padded. The movable clamping jaw 104 is intended to lie on a bottom surface or bottom edge of the table-tennis table, and is also preferably padded to prevent or limit wear and damage.
The movable clamping jaw 104 is slidably received in the clamp body 18 at or adjacent to the clamp end 22. The movable clamping jaw 104 is also slidably engaged with the lever handle 98, so that a pivot axle 108 of the lever handle 98 is slidable towards and away from a clamping surface 110 of the movable clamping jaw 104.
The biasing element 100 in this case is a projecting roller which is mounted at or adjacent to one end of the lever handle 98, close to the pivot axle 108, and which has a rotational axis 112 parallel with and offset from the pivot axis 114 of the lever handle 98.
Due to the roller 100 being offset from the pivot axle 108, with the lever handle 98 moved upwardly from a release condition towards or into the clamp body 18 and therefore to a locked condition whereby the clamp is engaged, the roller 100 forces the movable clamping jaw 104 from a release position towards the fixed jaw 106 and thus a clamping position. Once the rotational axis 112 of the roller 100 moves beyond or over the pivot axis 114 of the lever handle 98, the lever handle 98 is retained in the clamping position and is thus effectively locked, thereby maintaining the movable clamping jaw 104 in its clamping position.
Although dispensed with in this embodiment, a second biasing element for biasing the movable clamping jaw 104 into positive engagement with the roller 100 may be included. For example, the second biasing element may be a spring so that, when the lever handle 98 is in its release condition, the movable clamping jaw 104 is biased into engagement with the roller 100.
Although a roller 100 is suggested, any other suitable rollable element, such as a ball bearing, may be utilised. Alternatively, the rollable element may be dispensed with altogether and the biasing element 100 may be a protrusion of the lever handle 98.
To allow for table-tennis tables of different thicknesses, the pivot axle 108 of the lever handle 98 is slidably engaged with the clamp body 18. To adjust a position of the pivot axle 108, and thus the spacing of the movable clamping jaw 104 from the fixed jaw 106, a position adjuster 118 is provided.
The position adjuster 118 includes a rotatable cam spacer 120 for supporting the pivot axle 108 of the lever handle 98 at a plurality of different displacements from a rotational axis 122 of the cam spacer 120. The cam spacer 120 is a rotatable disk, in this case, with the rotational axis 122 being off centre. Beneficially, a perimeter edge 124 of the rotatable disk 120 includes a plurality of angularly spaced apart notches 126 to complementarily fit the pivot axle 108 of the lever handle 98. In this way, a position of the pivot axle 108 of the lever handle 98 can be step-wisely adjusted by rotating the cam spacer 120.
Advantageously, it is preferable that the notches 126 in the perimeter edge 124 of the cam spacer 120 represent a space between the movable clamping jaw 104 when in its clamping position and the fixed jaw 106.
So that a wider variety of table-tennis table thicknesses can be accommodated, the cam spacer 120 itself may conveniently be slidably adjustable on the clamp body 18. Consequently, ends of a supporting axle 128 of the cam spacer 120 are received in respective elongate slots 130 in the clamp body 18. Rotatable spacers 132 are also provided on the ends of the supporting axle 128, and a lug 134 is provided at or adjacent to the bottom of the elongate slots 130.
Each rotatable spacer 132 includes at least one notch 136 complementarily shaped to fit the associated lug 134. With the lug 134 located in the notch 136 of the rotatable spacer 132, the supporting axle 128 is at its lowest position. From here, the cam spacer 120 can be adjusted as required to set the spacing between the movable clamping jaw 104 and the fixed jaw 106. Beneficially, a graded display 138 is provided on one side of the cam spacer 120 indicating to a user the spacing of the jaws 104, 106 applicable to a given notch 136.
If the notch 136 and lug 134 are disengaged by sliding the supporting axle 128 along the elongate slot 130, the rotatable spacer 132 can be turned so that the lug 134 engages the perimeter edge 124 of the rotatable spacer 132 or another slot if different depth. This results in the cam spacer 120 adopting a raised condition. Beneficially, a further graded display can be provided on the other side of the cam spacer 120 indicating to a user the spacing of the jaws 104, 106 applicable to a given notch 136 whilst in this condition.
With the thickness of the table-tennis table determined, the rotatable spacer 132 can be set to its lowered condition or its raised condition. The cam spacer 120 can then be rotated to the closest applicable dimension, and then the pivot axle 108 of the lever handle 98 can be re-seated on cam spacer 120, effectively locking it in place via notches 126.
With the lever handle 98 lowered, the edge of the table-tennis table is slid between the movable clamping jaw 104 and the fixed jaw 106. The lever handle 98 is raised, thereby causing the movable clamping jaw 104 to move towards the fixed jaw 106 and thus clamp the edge portion of the table-tennis table therebetween. Once the biasing element 100 moves over-centre, the jaws 104, 106 become effectively locked relative to each other and the lever handle 98 is retained in its raised position.
Once set, the net-supporting device 14 can be very quickly released and re-attached to the table-tennis table, simply by operating the lever handle 98.
In use, and with the net-supporting devices 14 attached either side of the table-tennis table, the flexible elongate element 55 is tensioned via the engagement with the cartridge 28. The spring element 50 thereby automatically tensions the flexible elongate element 55 when the apparatus 10 is removed and then reattached without requiring further setup.
The same goes for the height setting of the net. Once the height is set via the tensioning of the flexible elongate element 55 and the height adjuster 80, no further adjustment should be necessary following removal of the apparatus 10 and re-erection.
It may be possible to utilise the above-described automatic tensioning system for the net independently of the above described over-centre clamping mechanism, and vice versa.
It is thus possible to provide table-tennis net apparatus which, once initially set up for a particular table-tennis table, will then take only moments for one person to re-erect when required. It is also possible to provide such apparatus which meets all of the requirements and regulations of the ITTF.
The embodiments described above are provided by way of examples only, and further modifications will be apparent to persons skilled in the field without departing from the scope of the invention as set forth in the accompanying claims.
Filing Document | Filing Date | Country | Kind |
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PCT/GB2013/050551 | 3/6/2013 | WO | 00 |