Dart and launcher

Abstract

A dart (2) for use with a dart blaster, the dart comprising a body (4), wherein the body comprises: a diameter to length ratio of 1:1.5 to 1:6, a centre of mass distance ≤ length / 2, a diameter of 10 to 30 mm and a rotational inertia ≥ 1x10^-5 kgm^2.

Description

[0001] DART AND LAUNCHER

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The present invention relates to a dart, more specifically to a dart for use with a dart blaster and an apparatus for launching the dart.

[0004] BACKGROUND OF THE INVENTION

[0005] Foam-based darts have been used in toy blaster devices for several years. The Nerf® blaster is an example of such a dart blaster that uses foam-based darts.

[0006] Gyroscopic flying rings are another type of device that are used in the toy market and typically comprise a cylindrical ring that is thrown by a user. An example of such a gyroscopic flying ring is the X-Zylo™ which was developed in the early 1990s. The advantage of such gyroscopic flying rings is that the rings can travel a further distance with more accuracy than a corresponding foam-based dart when thrown by a user, for the same input of kinetic energy

[0007] The use of gyroscopic flying rings with dart blasters has previously been attempted but has been found to be associated with several problems. For example, it has been found that when a gyroscopic flying ring is inserted into a dart blaster it is difficult to reload the rings, the blaster will require manual priming, the launch speed of the rings is slow, and the launching of the rings from the blaster imparts a limited rotational spin. In addition, gyroscopic flying rings are typically more expensive than traditional foam darts and have a larger size than foam darts such that the load capacity of the rings within a dart blaster is small. It has been found that the use of such gyroscopic rings in a dart blaster generally has a poor performance relative to standard darts due to their slow flight speed. In addition, it is not possible to provide semi or automatic firing using such gyroscopic flying rings with a dart blaster.

[0008] As an alternative, it is understood that the provision of more kinetic energy to a standard dart structure would be more dangerous for game play than using a standard foam dart. In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

[0009] It is an object of the present invention to address the above problems and seek to provide a dart with glide dynamics corresponding to those of a gyroscopic flying ring so that when the dart is launched it will travel a further distance at the same speed as a traditional dart and with greater accuracy.

[0010] BRIEF DESCRIPTION OF THE INVENTION

[0011] In a first aspect the present invention consists in a dart for use with a dart blaster, the dart comprising a body, wherein the body comprises: a diameter to length ratio of 1:1.5 to 1:6, a centre of mass distance < length / 2, a diameter of 10 to 30 mm and a rotational inertia > 1x10A-5 kgmA2 / s.

[0012] It has been found that darts made according to these parameters maintain a relatively high rotational inertia in flight which helps maintain glide angle and has the effect of keeping the dart stable. This provides a dart with a longer glide path than traditional darts, and with significantly better accuracy than traditional darts.

[0013] Preferably, the dart comprises a proximal end and a distal end, wherein the proximal is defined as the end of the dart that is nearest the dart launcher when the dart is in flight and the distal end of the dart is the end that is nearest the target when the dart is in flight.

[0014] Preferably, the diameter to length ratio is 1:1.5 to 1:3.

[0015] Preferably, the body of the dart comprises a cylindrical wall which is thicker at a distal end of the dart than at a proximal end of the dart so that the centre of mass of the dart is provided at or towards the distal end of the dart. Preferably, the body comprises an outer wall component and an inner wall component, wherein the diameter of the inner wall component is greater at the proximal end of the dart than the diameter of the inner wall portion at the distal end of the dart.

[0016] In one embodiment the dart may comprise a hollow interior. In this embodiment, the provision of a hollow interior within the body of the dart provides the dart with increased gliding surfaces that are closer to the centre of mass than a traditional dart.

[0017] Preferably, at least one end of the dart is open. The provision of a dart having at least one open end advantageously has the effect of providing improved gliding surfaces to the dart. In one embodiment, the dart has one open end. In another embodiment, the distal end of the dart is open and the proximal end of the dart is closed. In another embodiment the proximal end of the dart is open and the distal end of the dart is closed. In a further embodiment, both the proximal and distal ends of the dart are open. In the embodiment wherein the distal end of the dart is closed, the frontal area assists in increasing the impacting surface area to better disperse impact energy, improving safety.

[0018] Preferably, the body comprises a plurality of recesses. Preferably, the plurality of recesses are provided at the proximal end of the dart. Preferably, the recesses are provided within the cylindrical wall. Typically, four recesses are provided within the body. Preferably, the recesses are provided at regular intervals around the circumference of the body.

[0019] The provision of the plurality of recesses provided at the proximal end of the dart and the thicker wall portion at the distal end of the dart advantageously assists in moving the centre of mass of the dart forwards, thus assisting in improving the speed and stability of the dart when launched from a dart launcher.

[0020] Preferably, the distal end of the dart further comprises a lip. Typically, the lip projects from the substantially cylindrical wall at an angle. The provision of the lip at the distal end of the dart advantageously assists in reducing the impact force of the dart and helps to bring the centre of pressure of the dart forwards, thus assisting in improving the speed and stability of the dart when launched from a dart launcher.

[0021] Advantageously, the provision of a dart which comprises the structure and geometry of the present invention means that the dart can fly further and with more accuracy than a traditional foam dart. Furthermore, darts configured according to the invention can be made to similar dimensions to known darts, but with a lower mass, meaning a safer KED.

[0022] Preferably, the dart comprises urethane, polyurethane or rubber. The dart may be coloured to enhance aesthetic appearance and also increase visibility to aid in recovery. The dart may also be made translucent. If a phosphorescent material such as strontium aluminate or calcium aluminate is added to the plastic during molding, darts may be made to glow in the dark to provide for enhanced night-time use, aiding recovery and also simulating "tracer" round fire in game-play.

[0023] The dart of the present invention is advantageously more rigid in structure than a conventional gyroscopic flying ring so that the dart of the present invention is less likely to be deformed when launched from a dart launcher. In one embodiment, the dart of the present invention comprises a one-piece construction. Advantageously, the provision of a dart comprising a one-piece construction assists with the manufacturing process since fewer manufacturing steps are required, thus reducing cost.

[0024] As an alternative, the dart of the invention may have a multipart construction, wherein, for example, the body comprises a relatively softer outer part and a relatively more rigid inner part to provide support thereto. In this way, the rigidity of the external part can be optimized such that it is better gripped by the flywheels of a launcher and also softer on impact, whilst still allowing for the required structural rigidity to achieve the desired flight characteristics. It is preferred that the centre of pressure and the centre of mass of the dart are as close together as possible. Preferably, the centre of mass of the dart should be within 2 mm of the centre of pressure throughout the flight trajectory of the dart. In this embodiment, the speed range of the dart is approximately 150 to 30 feet per second (46 to 9 m / s) in flight, with an attack angle of between 0 and 15 degrees. Typically, both the attack angle and speed change the centre of pressure location of the dart.

[0025] Preferably, the rotational speed of the dart when launched from a dart launcher is > 100 rad / s.

[0026] Preferably, the linear velocity of the dart when launched from a dart launcher is > 18 m / s.

[0027] In a second aspect the present invention consists in a dart launcher for launching a dart according to the first aspect of the invention, wherein the dart launcher comprises, a cylindrical tube into which the dart is inserted before launch and a plurality of rotating flywheels, wherein each flywheel comprises an axis of rotation that is offset with respect to the other flywheel(s). It is preferred that the flywheels are arranged in pairs, preferably with the members of each pair opposite one another.

[0028] Preferably, the dart launcher comprises two flywheels. The flywheels may advantageously be adapted to impart a crush force of from 15N to 80N, preferably 30N.

[0029] The provision of a dart launcher having a plurality of flywheels, each flywheel having an axis that is provided at an angle that is offset with respect to the other flywheel advantageously imparts both linear and rotational velocity to a dart that is launched from the dart launcher. Indeed, the provision of a dart launcher according to the present invention advantageously provides a high rotational velocity to a dart that is launched from the dart launcher. Advantageously, the dart launcher imparts a high angular velocity to a dart that is launched from the dart launcher.

[0030] Preferably, each flywheel has an axis of rotation that is offset to the other flywheel at an angle of between 10 to 40 degrees, preferably at an angle of approximately 20 degrees. Typically, the angle by which the flywheels are offset with respect of one another is determined by the speed that is required or the geometry of the dart. Typically, a higher angle provides for more rotation of the dart when launched from the dart launcher. Flywheels can be powered by electrical motors or can be mechanically primed before trigger release, by for example, spring, pump action or rotation.

[0031] Advantageously, the dart launcher may allow for both semi and fully automatic firing modes.

[0032] The dart launcher of the present invention has the advantage that it uses gyroscopic forces and imparts a high rotational and linear velocity to the dart.

[0033] As used herein the term "and / or" means "and" or "or", or both.

[0034] As used herein "(s)" following a noun means the plural and / or singular forms of the noun.

[0035] The term "comprising" as used in this specification means "consisting at least in part of". When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present, but other features can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in the same manner.

[0036] It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7).

[0037] The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference.

[0038] To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and application of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be limiting.

[0039] Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.

[0040] BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0042] Figure 1 shows a side schematic view of a dart according to an embodiment of the invention;

[0043] Figure 2 shows a perspective side view of part of a dart launcher according to an embodiment of the invention;

[0044] Figure 3 shows a schematic cut-away side view of a further part of a dart launcher according to the invention;

[0045] Figure 4 shows a side plan view of a dart according to another embodiment of the invention; and

[0046] Figures 5a to 5f show views of a further dart according to the invention.

[0047] DETAILED DESCRIPTION OF THE INVENTION

[0048] Preferred embodiments will now be described with reference to Figures 1 to 5a -5f.

[0049] With reference to Figure 1, there is provided a dart 2 for use with a dart blaster, the dart comprising a body 4, wherein the body comprises: a diameter to length ratio of 1 :1.5 to 1:6, a centre of mass distance < length / 2, a diameter of 10 to 30 mm and a rotational inertia > 1x10A-5 kgmA2 / s.

[0050] The provision of a dart having a high rotational inertia has the effect of keeping the dart stable during its flight.

[0051] The dart comprises a proximal end 8 and a distal end 10, wherein the proximal is defined as the end of the dart that is nearest the dart launcher when the dart is in flight and the distal end of the dart is the end that is nearest the target when the dart is in flight.

[0052] In one embodiment, the dart comprises a hollow interior 6. The provision of a hollow interior within the dart provides the dart with increased gliding surfaces that are closer to the centre of mass than a traditional dart.

[0053] At least one end of the dart is open. The provision of a dart having at least one open end advantageously has the effect of providing improved gliding surfaces to the dart. In the embodiment shown in Figure 3 the distal end of the dart is closed. In this embodiment, the frontal area assists in increasing the impacting surface area to better disperse impact energy, improving safety.

[0054] The body of the dart comprises a plurality of recesses 12 that are provided at the proximal end of the dart. As shown in Figure 1, the recesses are provided at regular intervals around the circumference of the body. In the embodiment of Figure 1, four recesses are provided within the body.

[0055] Preferably, the body 4 of the dart comprises a cylindrical wall which is thicker at a distal end 10 of the dart than at a proximal end 8 of the dart so that the centre of mass of the dart is provided at the distal end of the dart. The body comprises an outer wall component 14 and an inner wall component 16, wherein the diameter of the inner wall component is greater at the proximal end of the dart than the diameter of the inner wall portion at the distal end of the dart. The provision of the plurality of recesses provided at the proximal end of the dart and the thicker wall portion at the distal end of the dart advantageously assist in moving the centre of mass of the dart forwards, thus assisting in improving the speed and stability of the dart when launched from a dart launcher.

[0056] The distal end of the dart further comprises a lip 18 which is provided at an angle to the cylindrical wall. The lip projects from the substantially cylindrical wall at an angle. The provision of the lip at the distal portion of the dart advantageously assists in reducing the impact force of the dart when it lands after it has been launched and helps to bring the centre of pressure of the dart forwards, thus assisting in improving the speed and stability of the dart when launched from a dart launcher.

[0057] Typically, the dart comprises urethane, polyurethane or rubber, which may be coloured to enhance aesthetic appearance and also increase visibility to aid in recovery. The darts may also be made translucent. If a phosphorescent material such as strontium aluminate or calcium aluminate is added to the plastic during molding, the dart may be made to glow in the dark to provide for enhanced night-time use, aiding recovery and also simulating "tracer" round fire in game-play.

[0058] The dart of the present embodiment comprises a one-piece construction, and here the dart is formed by injection molding. As will be appreciated, the provision of a dart that comprises a one piece construction assists in the manufacture of the dart, thus reducing costs.

[0059] With reference to Figure 1, a = the length of the dart, b = the leading edge thickness of the dart, c = the diameter of the dart, and d = the COM (Centre of Mass) distance

[0060] With reference to Figure 1, the dart has the following properties / characteristics which have been found to provide an optimum solution, i.e. a dart having the characteristics as set out below can fly for longer distances with a more stable and accurate flight path than a conventional foam dart:

[0061] Diameter to length having a ratio of 1:1.5; Centre of mass distance < length / 2;

[0062] Rotational speed > 100 rad / s; and

[0063] Linear velocity > 18 m / s

[0064] With reference to Figure 2, there is provided a dart launcher for launching a dart 2 according to the invention, wherein the dart launcher comprises a cylindrical tube 22 into which the dart is inserted before launch and a plurality of rotating flywheels 20, wherein each flywheel comprises an axis of rotation that is offset with respect to the other flywheel.

[0065] In the embodiment shown in Figure 2, the dart launcher comprises two flywheels.

[0066] Typically, each flywheel has an axis of rotation that is offset to the other flywheel at an angle of between 10 to 40 degrees, preferably at an angle of approximately 20 degrees.

[0067] The dart launcher of the present invention has the advantage that it uses gyroscopic forces and imparts a high rotational and linear velocity to the dart.

[0068] With reference to Figure 2, the canted flywheels of the dart launcher can provide for 100 rad / s rotational velocity in combination with greater than 60 fps linear velocity to a dart launched from the dart launcher.

[0069] With reference to Figure 3, there is illustrated schematically a preferred form of trigger mechanism for use in a dart launcher according to the invention. The Figure shows a cutaway section of the launcher and includes magazine 100 including darts 2, firing chamber 102 with flywheel 20 (second flywheel not shown, for clarity) and loading mechanism 103, consisting of spring mounted plunger or bolt 104 and trigger 105.

[0070] The loading mechanism 103 is shown in the safe, or pre-firing position, with dart 2 ready to be injected into chamber 102. Firing is initiated by a user moving trigger 105 to the left as viewed. Trigger 105 is releasably connected to bolt 104 and thus bolt 104 is also moved to the left against the force of bolt spring 106. At a set point, the mechanism is configured such that the trigger is released from the bolt, allowing the bolt to return rapidly towards the chamber, impacting the dart 2 that is in the breach, causing it to move into the chamber 102 where it is gripped by the flywheels 20 and fired. The mechanism by which the trigger and bolt are detached is preferably set such that the bolt delivers each dart 2 with a consistent force so that each dart is introduced to the flywheels with a consistent speed and attitude. The detachment mechanism could include, as an example, a cam of the loading mechanism and a follower of the trigger, whereby the trigger is moved out of register with the bolt as it travels along the cam. If the position of detachment is made to be variable, for example by allowing the position of the cam to be adjusted, dart delivery can be fine-tuned for optimum performance and can be used to accommodate for the gradual reduction in spring force of the bolt spring 106, through use, or even to allow for the use of different sizes of dart 2.

[0071] Figures 4 and 5a to 5f show an embodiment of the dart of the invention wherein the dart comprises an enclosed front. The frontal area of the dart assists in increasing the impacting surface area to better disperse impact area, improving safety.

[0072] In use, a dart 2 is inserted into a dart launcher. A user then fires the dart launcher to release the dart. The provision of a plurality of rotating canted flywheels that have an axis of rotation provided at an angle that are offset to one another means that the dart is launched with a high rotational velocity. In addition, the geometry and configuration of the dart as described above means that the centre of mass is provided at the distal end of the dart which provides for a more stable and thus more accurate flight path. In addition, the geometry of the dart as described above means that the dart can fly for further distances than a traditional foam dart.

[0073] The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention.

Claims

CLAIMS1. A dart for use with a dart blaster, the dart comprising a body, wherein the body comprises a diameter to length ratio of 1:1.5 to 1:6, a centre of mass distance < length / 2, a diameter of 10 to 30 mm and a rotational inertia > 1 xl 0A-5 kgmA2 / s.

2. A dart according to claim 1, wherein the body of the dart comprises a cylindrical wall which is thicker at a distal end of the dart than at a proximal end of the dart so that the centre of mass of the dart is provided at a distal end of the dart.

3. A dart according to claim 1 or claim 2, wherein the diameter to length ratio is 1 :1.5 to 1:3.

4. A dart according to any preceding claim, wherein the dart comprises a hollow interior.

5. A dart according to any preceding claim, wherein at least one end of the dart is open.

6. A dart according to claim 5, wherein the proximal end of the dart is open and the distal end of the dart is closed.

7. A dart according to any preceding claim, wherein the body comprises a plurality of recesses.

8. A dart according to claim 7, wherein the plurality of recesses are provided at the proximal end of the dart.

9. A dart according to any preceding claim, wherein the distal end of the dart further comprises a lip.

10. A dart according to claim 9, wherein the lip projects from the substantially cylindrical wall.

11. A dart according to any preceding claim, comprising urethane, polyurethane or rubber.

12. A dart according to any of claims 1 to 10, wherein the dart comprises both an elastomer and a foam.

13. A dart according to any preceding claim, including a phosphorescent material.

14. A dart according to any preceding claim, having a one piece construction.

15. A dart according to any of claims 1 to 13, having a multi-piece construction.

16. A dart according to any preceding claim, wherein the center of pressure and the center of mass of the dart are as close together as possible.

17. A dart according to claim 16, wherein the centre of mass of the dart is within 2mm of the centre of pressure throughout the flight trajectory of the dart.

18. A dart according to claim 17, wherein the speed range of the dart is approximately 46 to 9 m / s with an attack angle of from 0 to 15 degrees.

19. A dart according to claim 17 or claim 18, wherein the rotational speed of the dart when launched from a dart launcher is > 100 rad / s.

20. A dart according to any of claims 16 to 18, wherein the linear velocity of the dart when launched from a dart launcher is > 18 m / s.

21. A dart launcher for launching a dart, wherein the dart launcher comprises a cylindrical tube into which a dart is inserted before launch and a plurality of rotatable flywheels, the flywheels being disposed in opposed pairs, wherein each flywheel comprises an axis of rotation that is offset with respect to the axis of rotation of its pair.

22. A dart launcher according to claim 21, including one pair of flywheels.

23. A dart launcher according to claim 22, wherein each flywheel has an axis of rotation that is offset to the other flywheel at an angle of from 10 to 40 degrees, preferably 20 degrees.

24. A dart launcher according to claim 21 or claim 22, including a spring operated dart insertion mechanism for introduction of darts to the flywheels.

25. A method of manufacturing a dart, the dart being as set out in any of claims 1 to 20.

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