WO1996014112A1 - Magnetic connection between shaft and barrel of a dart for throwing - Google Patents

Magnetic connection between shaft and barrel of a dart for throwing Download PDF

Info

Publication number
WO1996014112A1
WO1996014112A1 PCT/GB1995/002593 GB9502593W WO9614112A1 WO 1996014112 A1 WO1996014112 A1 WO 1996014112A1 GB 9502593 W GB9502593 W GB 9502593W WO 9614112 A1 WO9614112 A1 WO 9614112A1
Authority
WO
WIPO (PCT)
Prior art keywords
dart
shaft
magnet
end part
flight
Prior art date
Application number
PCT/GB1995/002593
Other languages
French (fr)
Inventor
Colin Paxman
Original Assignee
Cobra Industries Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cobra Industries Ltd. filed Critical Cobra Industries Ltd.
Publication of WO1996014112A1 publication Critical patent/WO1996014112A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B6/00—Projectiles or missiles specially adapted for projection without use of explosive or combustible propellant charge, e.g. for blow guns, bows or crossbows, hand-held spring or air guns
    • F42B6/003—Darts

Definitions

  • This invention relates to improvements in or relating to darts, primarily darts used in playing a game.
  • darts comprise a barrel of metal with a point at one end and a shaft at the other end to which a stabilising flight is attached.
  • the flight itself is usually pushed into a cruciform slot at the end of the shaft, or at the end of a flight holder attached to the shaft. Replacing the flight may cause damage and use of a flight holding end part has the problem of providing a stable connection through a screwed connection or by push-fitting.
  • One of the objects of this invention is to provide a dart wherein a dart flight may be attached thereto in a manner which preferably allows rotation of the flight when impacted by another dart but which nevertheless provides a stable interconnection between the flight and body of the dart.
  • a dart comprising two or more parts at least two of the said parts being held in engagement by magnetic means.
  • a dart including an end part into which a flight may be received characterised by the provision of means providing magnetic attraction between the dart and the end part.
  • a dart shaft including an end part into which a flight may be received with the end part and the shaft being preferably relatively rotatable, the construction being characterised by the provision of means presiding magnetic attraction between the shaft and the end part.
  • the end of the shaft or dart body may include a boring into which a spigot, connected with the end part or the shaft into which the dart flight is fitted, may locate.
  • a magnet or magnetic material may be located in the base of the boring and with the spigot or an end part thereof being of a material which is magnetically attractive.
  • the main principle upon which this invention is based is the provision of magnetic attraction between the end part and the body or shaft of the dart with the magnetic attraction providing a good firm connection with stability but nevertheless preferably enabling the parts to rotate or even be detached.
  • the stability of the shaft and the end part which is rotatably located therein need not be provided by a good mechanical fit, and precision machining of the spigot and the bore are not essentially required due to the stable holding force provided by the magnetic means.
  • a further advantage of this construction is that the dart flight together with the end part may easily be attached to and detached from the body or shaft of the dart, thus enabling flights to be replaced in a simple manner.
  • the flights can be more securely retained in the end part and, if replacement is required, the whole flight and end part as a unit can be pulled away from the shaft and replaced by another unit.
  • Figure 1 shows a side view of a dart shaft, end part and flight of a first embodiment
  • Figure 2 shows a longitudinal section through the shaft and the end part of Figure 1 in a detached position
  • Figure 3 shows a longitudinal section through another embodiment showing a shaft and dart body in a detached position.
  • a shaft for a dart comprises a shaft body 1 which may be of plastic or metal with a screw threaded spigot 2 which, in use, engages a complementary threaded recess on the end of a body or barrel (not shown). The other end of the barrel will carry the point as is conventional.
  • the shaft part 1 includes a longitudinal boring 3 extending in from the end opposite to the threaded spigot 2 and the boring 3 may include a magnet 4 in the blind end.
  • the magnet may be of a metal, ceramic or rubber material or preferably a rare-earth magnet as is conventionally available.
  • the flight itself is secured in an end part 5 which has a cruciform slotted structure 6 into which the end 7 of a flight 8 may be positioned.
  • the end part includes a spigot 9 which is adapted to fit snugly but not tightly into the bore 3.
  • the spigot 9 at least is of a magnetically attractive material but it will be appreciated that the whole end part may be of a magnetically attractive material or in an alternative construction, a small magnet or magnetically attractive material may be located in the end 10 of the spigot.
  • the spigot 9 may rotate freely within the bore 3 but the parts are retained together in the required manner by virtue of the magnetic attraction.
  • Alternative methods of achieving the object of this invention may be exemplified by use of a shaft 1 which is itself magnetic and which attracts at least the spigot 9 of the end part or in an alternative the end part itself may be of a magnetic material and attracted to the material of the shaft or to an insert or other portion of the shaft material.
  • the magnet itself has a central bore which receives the spigot with the base of the spigot carrying a second magnet or a magnetically attractive material.
  • the magnetic attraction between the parts of a dart, particularly the shaft and an end part carrying the flight may be applied even when the two parts are made non-rotatable.
  • the advantage accruing from this construction is ease of detachment of the end part and the flight without requiring engaging formations in the two parts which can cause damage and difficulty in breaking the connection as in the prior art.
  • the embodiment shown in Figure 3 is similar in principle but here the shaft 1 carries the flight directly in an integral end part 5 and has a spigot 9 which engages boring 3 provided in the dart body or barrel 11.
  • the boring has a magnet 4 in this case to retain the spigot 9 on the shaft 1.
  • the barrel has the usual dart point 12.
  • This construction obviates the need for a screw connection between the dart barrel and the shaft. Such connections often become loose during use.
  • the dart barrel itself or the shaft or the end part may comprise a magnet with the adjacent connected part a magnet of opposed polarity or a magnetically attractive material.
  • a bearing may be provided to reduce friction at the engagement surfaces such as an area of point contact, a rolling bearing such as a ball bearing, or low friction coating.
  • ke ways or splines may be provided to allow longitudinal displacement without rotation.
  • a further advantageous arrangement uses a magnet in the nose of the dart barrel which may be used with a magnetic dart board and which may also retain, if required, a nose of magnetic or magnetically attractive material which carries a conventional dart point. Such a dart can then be used to play both conventional darts and magnetic darts games.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
  • Toys (AREA)

Abstract

A dart has two or more parts which are held together in normal use by magnetic means. This enables the parts to be separated easily for storage or replacement whilst maintaining a stable connection in use. In one embodiment a dart has a shaft (1) with threaded spigot (2) to engage a dart barrel (not shown) and a plain bore (3) with a magnet (4) in the base. A flight holder (5) has a spigot (9) with at least the end (10) being magnetically attractive to magnet (4). The arrangement avoids the need for precision matching or machinery of the spigot (9) and bore (3) to provide a stable fit. Removal is made easier due to lack of frictional binding.

Description

TITLE.
MAGNETIC CONNECTION BETWEEN SHAFT AND BARREL OF A DART FOR THROWING.
This invention relates to improvements in or relating to darts, primarily darts used in playing a game. Such darts comprise a barrel of metal with a point at one end and a shaft at the other end to which a stabilising flight is attached.
It has been proposed to make the flight, or a holder into which the flight is located, rotatable relative to the shaft for the purpose of reducing deflection where a following dart strikes a dart already impaled in the board. Constructions wherein the flight may spin or rotate relative to the shaft are known and in many constructions the portion holding the flight is engaged in the end of a shaft using some form of undercut connection whereby the parts may be snap fitted together. Such a construction has proved to be not very successful as either the parts are too tight and do not rotate easily or alternatively the parts are loose and move as the dart is thrown. This may create inaccuracies and is a feature which does not find favour with players.
The flight itself is usually pushed into a cruciform slot at the end of the shaft, or at the end of a flight holder attached to the shaft. Replacing the flight may cause damage and use of a flight holding end part has the problem of providing a stable connection through a screwed connection or by push-fitting.
One of the objects of this invention is to provide a dart wherein a dart flight may be attached thereto in a manner which preferably allows rotation of the flight when impacted by another dart but which nevertheless provides a stable interconnection between the flight and body of the dart.
According to this invention there is provided a dart comprising two or more parts at least two of the said parts being held in engagement by magnetic means.
In accordance with a second aspect of this invention there is provided a dart including an end part into which a flight may be received characterised by the provision of means providing magnetic attraction between the dart and the end part.
In accordance with a third aspect of this invention there is provided a dart shaft including an end part into which a flight may be received with the end part and the shaft being preferably relatively rotatable, the construction being characterised by the provision of means presiding magnetic attraction between the shaft and the end part. In a particular and preferred construction the end of the shaft or dart body may include a boring into which a spigot, connected with the end part or the shaft into which the dart flight is fitted, may locate. A magnet or magnetic material may be located in the base of the boring and with the spigot or an end part thereof being of a material which is magnetically attractive.
Thus the main principle upon which this invention is based is the provision of magnetic attraction between the end part and the body or shaft of the dart with the magnetic attraction providing a good firm connection with stability but nevertheless preferably enabling the parts to rotate or even be detached. Thus the stability of the shaft and the end part which is rotatably located therein need not be provided by a good mechanical fit, and precision machining of the spigot and the bore are not essentially required due to the stable holding force provided by the magnetic means.
A further advantage of this construction is that the dart flight together with the end part may easily be attached to and detached from the body or shaft of the dart, thus enabling flights to be replaced in a simple manner. In an extension of the invention, the flights can be more securely retained in the end part and, if replacement is required, the whole flight and end part as a unit can be pulled away from the shaft and replaced by another unit.
This invention is further described and illustrated with reference to the accompanying drawings which show two embodiments by way of examples only and not intended to be limitative.
In the drawings:
Figure 1 shows a side view of a dart shaft, end part and flight of a first embodiment, Figure 2 shows a longitudinal section through the shaft and the end part of Figure 1 in a detached position, and Figure 3 shows a longitudinal section through another embodiment showing a shaft and dart body in a detached position. Referring to the drawings, a shaft for a dart comprises a shaft body 1 which may be of plastic or metal with a screw threaded spigot 2 which, in use, engages a complementary threaded recess on the end of a body or barrel (not shown). The other end of the barrel will carry the point as is conventional. The shaft part 1 includes a longitudinal boring 3 extending in from the end opposite to the threaded spigot 2 and the boring 3 may include a magnet 4 in the blind end. The magnet may be of a metal, ceramic or rubber material or preferably a rare-earth magnet as is conventionally available.
The flight itself is secured in an end part 5 which has a cruciform slotted structure 6 into which the end 7 of a flight 8 may be positioned. The end part includes a spigot 9 which is adapted to fit snugly but not tightly into the bore 3. The spigot 9 at least is of a magnetically attractive material but it will be appreciated that the whole end part may be of a magnetically attractive material or in an alternative construction, a small magnet or magnetically attractive material may be located in the end 10 of the spigot.
With such an arrangement the spigot 9 may rotate freely within the bore 3 but the parts are retained together in the required manner by virtue of the magnetic attraction.
Alternative methods of achieving the object of this invention may be exemplified by use of a shaft 1 which is itself magnetic and which attracts at least the spigot 9 of the end part or in an alternative the end part itself may be of a magnetic material and attracted to the material of the shaft or to an insert or other portion of the shaft material.
In another construction the magnet itself has a central bore which receives the spigot with the base of the spigot carrying a second magnet or a magnetically attractive material.
In an alternative arrangement according to this invention the magnetic attraction between the parts of a dart, particularly the shaft and an end part carrying the flight, may be applied even when the two parts are made non-rotatable. The advantage accruing from this construction is ease of detachment of the end part and the flight without requiring engaging formations in the two parts which can cause damage and difficulty in breaking the connection as in the prior art. Thus it is not an essential feature of this invention to provide for rotation between the two parts which are connected by magnetic attraction.
The embodiment shown in Figure 3 is similar in principle but here the shaft 1 carries the flight directly in an integral end part 5 and has a spigot 9 which engages boring 3 provided in the dart body or barrel 11. The boring has a magnet 4 in this case to retain the spigot 9 on the shaft 1. The barrel has the usual dart point 12.
This construction obviates the need for a screw connection between the dart barrel and the shaft. Such connections often become loose during use.
In a further arrangement, not illustrated, the dart barrel itself or the shaft or the end part may comprise a magnet with the adjacent connected part a magnet of opposed polarity or a magnetically attractive material.
In yet a further arrangement mutually opposed forces due to magnetic repulsion may be utilised in order to retain in engagement one part of the dart relative to the other. Thus two magnets with adjacent similar poles are positioned to repel one part into abutment with a stop means to form the engagement.
Where the engaged parts are to be rotatable a bearing may be provided to reduce friction at the engagement surfaces such as an area of point contact, a rolling bearing such as a ball bearing, or low friction coating.
Where the engaged parts are not to be relatively rotatable, ke ways or splines may be provided to allow longitudinal displacement without rotation.
A further advantageous arrangement uses a magnet in the nose of the dart barrel which may be used with a magnetic dart board and which may also retain, if required, a nose of magnetic or magnetically attractive material which carries a conventional dart point. Such a dart can then be used to play both conventional darts and magnetic darts games.

Claims

C A TMS
1. A dart comprising two or more parts characterised in that at least two of the said parts are held in engagement by magnetic means.
2. A dart in accordance with Claim 1, wherein one part is an end part which retains a flight, the magnetic means providing magnetic attraction between a second part of the dart and the said end part.
3. A dart shaft including an end part into which a flight may be received with the end part and the shaft being preferably relatively rotatable, the construction being characterised by the provision of means providing magnetic attraction between the shaft and the end part.
4. A dart including a shaft into which a flight may be inserted and a body, the shaft being retained in engagement with the body by magnetic means.
5. A dart in accordance with any preceding claim wherein the parts held in engagement by said magnetic means are relatively rotatable. O 96/14112 PC17GB95/02593
6. A dart according to any preceding claim wherein an end of the shaft or the dart body includes a longitudinal boring into which a spigot, connected with the end part or the shaft into which the dart flight is fitted, may locate.
7. A dart according to Claim 6, wherein a magnet or magnetic material is located in the base of the boring and with the spigot or the end thereof being of a material which is magnetically attractive.
8. A dart according to Claim 6, wherein a magnet or magnetic material is provided in the spigot with the boring including a material which is magnetically attractive.
9. A dart according to any preceding claim wherein the magnet means comprises a magnet operatively associated with a magnetically attractive material or two magnets operatively associated.
10. A dart according to any preceding claim, wherein the engagement between the parts and produced by the magnetic means is effected through surfaces having low friction to rotational moments.
11. A dart according to any preceding claim, wherein one of the parts at least comprises a permanent magnet.
12. A dart according to any preceding claim, wherein the parts are held in engagement through abutment surfaces using mutual repulsion of opposite poles of the magnetic means.
13. A dart in accordance with any preceding claim, wherein the barrel has a forward nose incorporating a magnet for playing a magnetic darts game where the magnet is capable of attaching the dart to a dart board, when thrown, by magnetic attraction, and wherein a nose part carrying a point may be selectively attached to the said magnet for playing a conventional darts game.
14. A dart in accordance with Claim 13 wherein said magnet also secures another part of the dart such as a shaft or flight carrying end part.
15. A dart constructed and arranged to function as described herein and exemplified with reference to the drawings.
PCT/GB1995/002593 1994-11-04 1995-11-03 Magnetic connection between shaft and barrel of a dart for throwing WO1996014112A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9422299.9 1994-11-04
GB9422299A GB9422299D0 (en) 1994-11-04 1994-11-04 Improvements in or relating to darts for throwing

Publications (1)

Publication Number Publication Date
WO1996014112A1 true WO1996014112A1 (en) 1996-05-17

Family

ID=10763916

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1995/002593 WO1996014112A1 (en) 1994-11-04 1995-11-03 Magnetic connection between shaft and barrel of a dart for throwing

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GB (2) GB9422299D0 (en)
WO (1) WO1996014112A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITPT990006A1 (en) * 1999-03-16 2000-09-16 Salvatore Lardieri DOSING DEVICE WITH MAGNETIC COUPLINGS
NL2007754C2 (en) * 2011-11-09 2013-05-14 Ferdinand Blom DART ARROW AND COUPLER FOR A DART ARROW.
GB2605986A (en) * 2021-04-20 2022-10-26 Nodor International Ltd Improved dart

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4109915A (en) * 1976-09-20 1978-08-29 Bottelsen Walter Edward Breakaway dart
US4119316A (en) * 1977-03-04 1978-10-10 Cling-Cal Corporation Magnetic dart toy
US4457514A (en) * 1982-09-30 1984-07-03 Paxman Colin J Darts
US4978130A (en) * 1986-05-29 1990-12-18 Farler Charles W Dart flight rotation shaft and flight rotation shaft assembly

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4109915A (en) * 1976-09-20 1978-08-29 Bottelsen Walter Edward Breakaway dart
US4119316A (en) * 1977-03-04 1978-10-10 Cling-Cal Corporation Magnetic dart toy
US4457514A (en) * 1982-09-30 1984-07-03 Paxman Colin J Darts
US4978130A (en) * 1986-05-29 1990-12-18 Farler Charles W Dart flight rotation shaft and flight rotation shaft assembly

Also Published As

Publication number Publication date
GB9422299D0 (en) 1994-12-21
GB2294645A (en) 1996-05-08
GB9522524D0 (en) 1996-01-03

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