CA3166695A1 - Dart-launching slingshot - Google Patents

Abstract

The Dart-launching Slingshot is comprised of a handheld Y-shaped slingshot-frame having a hand-grip portion that is centrally-joined to first and second elastic fixation prongs, each prong having a tip that is adapted for attachment of an elastic band. An elastic band is affixed at one end to the slingshot-frame's first fixation prong and affixed at its other end to the slingshot-frame's second prong. One or more darts which are configured for entangled side-engagement onto the mid-portion of the elastic band by means of an axially-aligned pair of pins that project from opposite sides of the dart's shaft. Various dart embodiments are disclosed that enable a wide variety of applications; ranging from shooting a foam-tipped toy dart suitable for children's games to shooting an explosive-tipped dart suitable for hunting, self-defence or military engagement. Fishing and dartboard gaming embodiments are also disclosed

Description

Dart-launching Slingshot Field of the Invention This invention relates to slingshots, archery, dartboard games, fishing gear and firearms.
Background and description of the prior art Archery and slingshot devices comprise one of mankind's earliest class of inventions. Originally used as weapons of tribal warfare, in modern times, the advent of firearms has largely relegated their use to sporting activities.
A "slingshot" can be defined as a roughly Y-shaped frame having a handle portion and two centrally-joined prong portions, each affixed at their distal end to a pair of elastic bands that extend rearwards where they affix onto each side of a pouch, the pouch carries and ballistically launches a small spherical projectile towards its user-selected target. The much larger archery "longbow" utilizes a tensioned bowstring to launch an "arrow" projectile ("arrows" are rod-shaped shafts that have a pointed front end and a bowstring-notched rear end that is flight-stabilized by nearby "fletching" vanes affixed radially around the shaft). A "dart" is a miniature hand-thrown arrow that is typically used for indoor target games; it is side-gripped between thumb and index finger near its balance point and then manually launched towards its "dartboard" gaming target (rather than being propelled from a notched rear shaft-end as is practiced in longbow archery).
The present invention draws on functional elements inherent to all of the above devices; the result of their integration is a simpler and more efficient slingshot that ballistically launches darts (instead of small spherical projectiles). The darts are re-configurable to serve a broad range of weaponry and sporting functions. At the lower end of this range, the dart can be configured as a harmless foam-tipped toy that is suitable for use in children's games.
Towards the upper end of this range, a series of dart embodiments, each one increasingly destructive; ultimately results in a dart that can be configured to act as a firearm that explodes on contact with its target.
The prior art device that is most relevant to the present invention can be viewed at www.snipersling.com. Their product line includes "slingshot darts" that are somewhat similar to the darts used within the present invention. YouTube also has "slingshot dart"
videos showing DIY versions of the same apparatus. Slingshot darts are launched from a substantially conventional slingshot that has been modified with a purpose-built elastic assembly, in which the central pouch (normally used to propel a small spherical projectile) is replaced by a short length of wire or bowstring material that propels the dart. The slingshot darts sold by Snipersling are used in conjunction with their modified slingshot.
Each of Snipersling's prior art slingshot darts includes a single deep notch that is formed on the dart's shaft near its pointed front end. The notch is angled forward into the shaft and extends far enough that the short length of wire at the middle of their slingshot's modified elastic assembly can be engaged into it, thereby enabling the slot to act as a launching tractor: it pulls Date Recue/Date Received 2022-07-04 directly along the dart's central axis to propel it forward. To launch the engaged dart, the user first pulls back on its fletched rear end, thereby stretching and energizing the slingshot's pair of elastics. When ready to fire, the dart is released and is thereby propelled forward; en route to its target, the short tractor-wire disengages from the dart-notch as it flies past the pair of flaccid elastics.
There are several drawbacks to this type of prior art dart-launching slingshot apparatus. The darts require a 3-part elastic assembly which is somewhat complex to fabricate and use.
Furthermore, the presence of the notch and propulsion wire on the dart's central axis prevents using a hollow tube as the dart-shaft. That limitation in turn prevents full sliding mobility of a firing pin cooperatively contained within the dart; an unobstructed dart-tube is an essential prerequisite for implementing the explosive-tip dart embodiment of the present invention, described further below. Furthermore, solid dart shafts are heavy so their sharply-pointed front end tend to embed very firmly in the target, thereby limiting the dart's utility when used in traditional dartboard gaming applications.
Another drawback of the notched-dart prior art is its potential to inflict serious injury to the user's hand. The problem occurs if the user inadvertently engages the dart's open-sided notch onto the elastic band's central cord-portion with its open side facing away from them, the resulting propulsion geometry can cause the dart to veer towards their hand (YouTube videos by Snipersling testers show gruesome images of darts accidentally impaled into a user's hand). To address this serious safety problem, Snipersling (and other notched-dart manufacturers) sell and recommend using an armoured glove to hold their slingshot frame. This safety constraint increases the cost of their product and inhibits ergonomic usability. The present invention utilizes novel propulsion geometry that eliminates the tenancy of a released dart to veer towards the user's hand.
Regarding the explosive-tip embodiment, YouTube reveals a prior art explosive arrow tip that is relevant to understanding the present invention (search for videos of "Bow-Mag explosive arrow tip"). The advantages of the present invention's approach to configuring an explosive tip will be made evident when reading its detailed description below.
Another relevant instance of prior art relating to an explosive arrow tip can be found in the PCT
application by Yuenfeng Tian: PCT/CN2016/000196. Again, the comparative advantages of the present invention's approach to configuring an explosive tip will be made evident when reading its detailed description further below.
US 9,903,681 B2 by Walterscheid is also worth noting as being somewhat relevant to the present invention's dart-launching configuration because it deals with foam-tipped arrows used in children's games.

Date Recue/Date Received 2022-07-04 The invention in its general form will first be summarized by a textual description, and then its implementation in terms of specific embodiments will be described with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.
Summary Of The Invention The invention is a Dart-launching Slingshot comprised of three main components:
1. A handheld slingshot-frame having a hand-grip portion centrally-joined to first and second prongs, each prong having its tip configured for fixation to an end of an elastic band;

2. An elastic band, affixed at one end to the slingshot-frame's first prong and affixed at its other end to the slingshot-frame's second prong;

3. One or more darts, each dart configured for entangled engagement onto the mid-portion of the elastic band by means of a pair of axially-aligned pins that project from opposite sides of the dart's shaft and located forward of the dart's balance point.
Usage of the dart-launching mechanism:
To prepare a dart for launch, the user holds their slingshot frame (also referred to below as the "dart-launcher") in one hand while using their other hand to engage a dart onto the dart-launcher's elastic band. Entangled engagement onto the band is accomplished by draping a short middle portion of the elastic over the dart, onto the opposite side of its shaft from the user;
this draped mid-portion is also positioned immediately behind the shaft's pair of projecting engagement pins. The dart is then manoeuvred slightly back, towards the user while simultaneously reorienting it such that the elastic band becomes wrapped around the pins;
engaged first against their rear side and then tangent against their near side. As this wrapping occurs, the dart is being drawn fully back by its rear (fletched) end; as the user adds tension to the elastic, its short central portion will be drawn into ever tighter entanglement onto the rear and near sides of the two projecting pins (as well as onto the far side of the dart's shaft). Once the entire elastic has been fully tensioned and the dart has been aimed to the user's satisfaction, the dart's fletched rear end is released to launch it towards its target. As the dart passes the point where tension in the elastic band becomes fully relaxed, its mid-portion will automatically release fully from the dart to allow it to fly cleanly past the slingshot-frame.
Elastic band embodiments:
The simplest embodiment is a continuous elastic band that loops away from the slingshot frame's two fixation prongs and is sized in length to correspond to the user's draw length when fully extended (being stretched to approximately 5 times its flaccid length).
It typically is comprised of a length of flat latex band that tapers in width towards its midpoint in order to facilitated engagement onto the dart's pair of axially-aligned propulsion pins. A length of Date Recue/Date Received 2022-07-04 tubular latex may also be employed however pin engagement is more difficult, (unless part of the tube's wall is cut away to form a flat section at its mid portion).
In a preferred embodiment, the elastic band is comprised of two long bands of equal length joined by a short length of robust string. The string engages onto the dart's pair of projecting pins (instead of the more fragile latex), thereby extending the life of the elastic band assembly, while simultaneously enabling the use of smaller engagement pins.
Dart embodiments The Dart-launching Slingshot's can be used as a toy by configuring a foam tip on the dart so that acts as a harmless bumper. In another embodiment, the dart is equipped with a standard, somewhat sharp "target point" that is used in conventional, longbow archery.
In another, more dangerous embodiment, the dart is equipped with a standard "broadhead" point used in conventional bow hunting. In its most dangerous embodiment, used for self defence, law enforcement or big game hunting, the dart is equipped with an explosive tip that utilizes an inertially-activated firing-pin to detonate an explosive charge held within a chambered tip.
In a preferred embodiment, the Dart-launching Slingshot is configured as a dartboard game that allows two players to safely compete indoors (in much that same fashion as a conventional, hand-launched game of darts). This embodiment includes a robust dartboard made of wood and darts that have a standard wood-screw tip. The tip enables the dart to embed firmly into the target while enabling easy removal (by rotating the dart counterclockwise to back out its threaded tip from the wooden dartboard).
Engagement-pin embodiments The pair of axially-aligned pins used to selectively engage the dart to the elastic band may be integrated with a collar that fits over and is glued to the tubular shaft. In another embodiment, the dart's pair of elastic-engagement pins are separately formed by gluing short pins in axial alignment onto the outside of the dart's shaft. Both of these bombardments require very secure fixation to prevent breakage.
In a more robust embodiment, the pair of pins is formed by a single pin that pierces the tubular shaft to project from both sides. While simpler to fabricate, this pin-pair embodiment obstructs the travel of an inertially-activated firing pin, thereby disabling the ability of a non-explosive dart to carry the explosive tip detailed below. In another embodiment, the pin-pair is transversely offset from the dart shaft's axis, thereby enabling the entangled elastic to symmetrically apply propulsive force along the dart's axis; however, having that symmetry during acceleration comes at the expense of having slightly asymmetric flight aerodynamics during the dart's glide path to its target (which slightly degrades accuracy).

Date Recue/Date Received 2022-07-04 List of figures Figure 1 illustrates the posture of a user who is ready to grasp their Dart-launching Slingshot in its fully-stretched, ready to launch configuration.
Figure 2 illustrates the Dart-launching Slingshot components shown in Figure 1 in a pre-launch configuration, the dart component having a standard "target-point" arrow tip mounted to its hollow shaft.
Figure 3 also illustrates the Dart-launching Slingshot shown in Figure 1 but at a larger scale that shows how the Dart-launching Slingshot's elastic band engages in asymmetric side-entanglement with the dart's pair of aligned engagement pins.
Figure 4 shows the Dart-launching Slingshot of Figure 2 with a relatively harmless suction-cup tip in place of the removable target-point.
Figure 5 shows the Dart-launching Slingshot of Figure 2 with a relatively harmless foam tip in place of the removable target-point.
Figure 6 shows the Dart-launching Slingshot of Figure 2 with a relatively deadly hunting broadhead tip in place of the removable target-point.
Figure 7 shows the Dart-launching Slingshot of Figure 2 with a relatively deadly explosive tip in place of the removable target-point.
Figure 8 illustrates an exploded view of the explosive-tipped dart shown in Figure 7.
Figure 9 illustrates how the explosive-tipped dart of Figure 7 is held together.
Figure 10 further illustrates a hidden-line view of the explosive-tipped dart shown in Figure 8.
Figure 11 illustrates a simple dart having a solid shaft pierced by a transverse pin.
Figure 12 illustrates the solid-core dart of Figure 11 having a soft sponge tip.
Figure 13 illustrates the solid-core dart of Figure 11 having a sharp triangular tip.
Figure 14 illustrates a hollow-core version of the dart shown in Figure 11 as well as an aiming device added to its slingshot-frame.
Figure 15 illustrates an embodiment that combines the features of both solid-core and hollow-core dart shafts.

Date Recue/Date Received 2022-07-04 Figure 16 illustrates internal components of the dart shown in Figure 15 and how they enable the same dart to be reconfigured to have a wide range of applications.
Figure 17 illustrates a novel mechanism for affixing the elastic to the prongs of slingshot-frame.
Figure 18 illustrates an embodiment of the explosive-tip dart that detonates a centerfire bullet.
Figure 19 illustrates an embodiment of the elastic having a centrally located string portion that engages the dart.
Figure 20 illustrates an embodiment of the slingshot frame with extra clearance to allow a spinning dart to freely fly past it.
Figure 21 illustrates an exploded view of a dart embodiment that utilizes a single-piece pair of fletching vanes mounted to the shaft in a slot and with angled fletching to rifle-spin the dart.
Figure 22 illustrates a dartboard game embodiment of the invention.
Detailed description of the Figures Figure 1 illustrates the approximate posture that a right-handed user 2 would assume for grasping onto their Dart-launching Slingshot 1, while the apparatus is in its ready-to-launch configuration. The user's left hand 6 grasps the slingshot-frame 3 and their right hand 7 grasps the dart 5 (after having first engaged it to the elastic via a pair of engagement pins 12 described below). Elastic band 4 thereby selectively joins dart 5 to frame 3 in a manner that enables user 1 to stretch the elastic to arm's length and then release the energized dart to fly forward.
Figure 2 is a large-scale illustration of the Dart-launching Slingshot shown in Figure 1 but with the components positioned in its pre-launch configuration. Slingshot-frame 3 is a roughly Y-shaped member, having a grip portion 8 centrally joined to first and second elastic fixation prongs 9 and 10. The illustrated Y-shaped frame is typical of a wide variety of "slingshots" that are commercially available; their shape can vary significantly while providing the same launch-platform functionality as the frame shown in Figure 2; those existing and commonly available slingshots can generally be adapted for use as frame 3 in the present invention.
The illustrated example of slingshot-frame 3 has an ergonomically shaped grip portion 8 that provides four finger indentations; when gripped by right-handed user 1, the grip's indentations position the user's left index finger adjacent to the upper elastic fixation prong 9 while their left thumb fits adjacent to the frame's lower fixation prong 10, thereby providing an ergonomic frame geometry that minimizes leverage forces when forcefully stretching elastic 4.
This style of slingshot-frame 3 is compact and thin enough to be easily stored in a pocket or purse. Other common slingshot frame styles utilize a more linear Y-shape that is bulkier however the frame's more symmetrical shape lends itself to holding the two elastic support prongs disposed Date Recue/Date Received 2022-07-04 horizontally instead of vertically as shown in Figure 2 (the side-by-side prongs shooting posture is preferred by some slingshot enthusiasts to the over/under prongs orientation shown). Both frame-usage styles and orientations can be practiced when using a suitably configured embodiment of the Dart-launching Slingshot. Left-handed users are also easily accommodated.
Elastic band 4 can be affixed to frame-prongs 9 and 10 using any of the commonly practiced fixation methods. The illustrated fixation is an elastic binding wrapped around prongs 9 and 10.
This is the simplest and most common style of band attachment; it consists simply of a length of thin elastic that is repeatedly stretch-wrapped around each prong of the slingshot frame 3 and tuck-secured to itself, thereby capturing and securing a folded-over end-portion of elastic band 4 against each prong's opposite side. When stretched over square prong-ends as shown in Figure 3, the upper and lower end portions of elastic band 4 are properly oriented in alignment with pins 12, (which facilitates the elastic's easy engagement onto dart 5 and contact-free flight of the dart once it is released). Another common elastic fixation means is comprised of a small clamp built into each prong-end that grips onto each end of the elastic band (not illustrated). A
novel elastic band locking mechanism is also proposed as part of this invention (see Figure 17).
Elastic band 4 is typically made of high-elasticity latex rubber and may be cut from lengths of widely available exercise band material. When used for propelling high energy hunting darts the elastic 4 may a strip of robust exercise band material such as TheraBand GoldTM. Less robust bands cut from TheraBand TM Blue or Yellow are typically used for propelling lower energy or toy darts. The robust elastic band shown in Figure 2 is tapered towards its midpoint for optimal high-energy propulsion. At its two anchored ends, (i.e. where it is affixed to prongs 9 and 10), the illustrated elastic band 4 is approximately 1 inch wide; it tapers in width down to approximately 1/2 inch wide near its midpoint 11 thereby enabling it to more easily engaged onto the pair of coaxial pins 12 on dart 5. The narrowed width at 11 can be significantly narrower than shown; a configuration that will facilitate even easier engagement onto dart 5 at the expense of less energy being stored in the elastic. Longevity of the elastic is diminished if its engagement contact area is too small; in practice, a 1/2" wide engagement portion 11 will fold over onto itself as the tension on it increases, thereby forming a strong and durable engagement portion that is narrow enough to fully engage onto pins 12 (see Figure 3).
Dart-shaft 14 is a short (approximately 6-inch) length of carbon arrow shaft tubing; in this case its outer diameter is 7.8 mm and its inner diameter is 6.2 mm. That carbon shaft configuration is popular for conventional archery and lends itself to cost-effective sourcing of the parts used to fabricate dart 5. More importantly, the strong yet lightweight carbon shaft's inner diameter of 6.2 mm facilitates implementation of an inertially activated explosive tip that can be affixed to shaft 14 (see tip 24 in Figures 8, 9 and 10).
In Figure 2, dart 5 is configured to mount a conventional screw-on archery target point 16. A
standard arrow insert 15 is threaded onto the threaded target point so both components can slide snugly into the shaft and abut securely against its front rim (see Figures 9 and 10 for insert Date Recue/Date Received 2022-07-04 details). The insert may be glued in place however for easy removal of the insert and tip, a simple band of adhesive tape around the joint (not shown) may be used instead.
Easy removal of the insert and its screwed-in tip is needed in order to convert this target-point dart to the explosive-tip dart of Figures 9 and 10. The dart in Figure 2 shows an (optional) insert 15b inserted into the rear end of shaft 14. When present, the rear insert is robustly glued in place so it can serve as a functional element in the explosive-tip dart mechanism of Figures 9 and 10.
In the illustrated example, the pair of axially-aligned pins 12 used to engage dart 5 onto elastic 4 is affixed to dart-shaft 14 by means of integral pin-collar 13. The collar is glued in place far enough forward of the dart's balance point to provide a strong pulling geometry when its pins 12 are engaged onto the elastic's narrow middle portion 11. To further insure good flight characteristics, the dart includes two or more fletch vanes 17, which are symmetrically affixed around the rear portion of shaft 14. The fletch vanes generate aerodynamic drag that keeps the dart-shaft flying straight towards its target without any pitch or yaw deviations that would degrade accuracy.
To facilitate a user's secure grasp on the rear end of dart 5 while pulling forcefully to energize elastic band 4, one or more high friction pads 18 may be affixed to the shaft portion proximate its rear end. An alternate method of providing a suitable grip for pulling back on dart 5 is to affix a bulbous knob to the shaft's rear end (not illustrated). Adhering a pair of high-friction pads 18 onto the left and right sides of shaft 14 is generally preferable to a rear knob because the pads are lighter, cheaper and more aerodynamic than a trailing knob. Furthermore (referring to Figure 1) it is evident that the user 1 can only draw back as far as their arm's reach so the further forward they grip into dart 5, the more draw-back energy they can store into elastic 4.
Figure 3 is a large-scale illustration of the fully-stretched Dart-launching Slingshot shown in Figure 1. Slingshot frame 3 and continuous elastic band 4 are joined together at the ends of prongs 9 and 10 to form a launching platform for dart 5. Referencing Figure 2, it becomes clear how the user can selectively couple the dart's pair of engagement pins 12 onto the narrowed central portion of elastic 4. The angled position of dart 5 shown in Figure 2 enables its shaft 14 to be moved against the slack elastic 4 at or near its central portion11. In Figure 3, it is evident that the dart shown in Figure 2 has been manoeuvred by the user until the center portion of the elastic 11 has become entangled around the far side of the dart, while its upper and lower elastic portions have become stretched around the back side of the two projecting pins 12 and have come to bear against the pins' near sides. This stretched force geometry results in the strong tension of the two long portions of elastic 4 (that are joined to prongs 9 and 10) being slightly offset to the left with respect to the dart's central axis (a left-handed user would flip this asymmetry towards the right).
When the dart 5 is asymmetrically engaged in this manner onto the center portion 11 of elastic band 4, the user can pull back at 18 as far as ergonomically possible, while aiming the dart at a desired target. When released, the dart accelerates until the pins 12 become disengaged from Date Recue/Date Received 2022-07-04 the flaccid elastic, whereupon it continues its flight past slingshot-frame 3.
Note that, since the strong force vectors of the two long elastic portions are slightly asymmetric, there will be a slight torquing force to the right while the dart is in its short acceleration phase of its ballistic trajectory towards the target. The slight torquing force experienced to the right during acceleration will cause a slight inaccuracy bias towards the right of the desired target however the user can easily learn to compensate for this bias error by sighting with the calibrated aiming wire 31 shown in Figure 14. The large diameter tips on some dart embodiments will exacerbate this inaccuracy phenomenon and heighten the need for accurate calibration of the aiming wire (see Figures 7, 12 and 14). Note that to facilitate the radical deformation of elastic 4 as it stretches around pins 12 (and to also prevent premature wear of the latex material), the band's center portion 11 should be lubricated with talcum powder, thereby enabling it to slide more easily as it deforms.
Note also that, while this slightly asymmetric sling-drive geometry will bias the dart to fly slightly to the right of the target (i.e. away from the illustrated user's left hand), it also insures that the present invention is inherently safer than the notched-dart prior art (which, as described above in the background, is prone to accidentally steering a released dart towards the user's hand and inflict serious injury).
Figure 4 shows the Dart-launching Slingshot of Figure 2 with a harmless suction-cup tip 19 mounted in place of the removable target-point tip 16. This configuration enables the Dart-launching Slingshot to serve as a safe children's toy that can shoot darts which stick to flat surfaces such as windows without causing damage (provided the power of elastic

4 has been adequately reduced). To modify the illustrated dart-launcher for use as a low-powered toy, a narrower strip of thin latex replaces the more robust elastic band 4 (not illustrated). For this toy embodiment, the dimensions of slingshot-frame 3 may also be scaled down to provide a better-fitting grip for a child's smaller hand.
Figure 5 shows the Dart-launching Slingshot of Figure 2 with a harmless foam bumper-tip 20 in place of the removable target-point. Like the suction-cup tipped dart of Figure 4, this embodiment may also serve as a safe toy that can be used for target games. To optimize the dart's flight accuracy, the side of its bulbous foam bumper-tip 20 is preferably dusted with talcum powder to minimize friction where it contacts elastic band 4. The end of the foam tip may also be dusted with coloured chalk so that contestants shooting in a game can see where each of their shots has bounced of its target and left behind a colour-coded chalk mark.
Figure 6 shows the Dart-launching Slingshot of Figure 2 when equipped with a relatively deadly broadhead tip 21, used for hunting (in place of the removed target-point tip).
Many styles of arrow points are available for threading into the dart to suit different sporting scenarios.
Figure 7 shows the Dart-launching Slingshot of Figure 2 when equipped with an explosive tip assembly 22 (in place of the removed target-point tip 16). Explosive tip 22 is configured for Date Recue/Date Received 2022-07-04 firing standard rimfire 22 calibre charges that detonate on contact with a target. To convert the dart 5 from its target-point tip configuration to this explosive-tip configuration, the target-point 16 and its threaded insert 15 shown in Figure 2 are removed and then the dart's hollow shaft is fitted with the required explosive charge components as detailed further below.
Figure 8 illustrates detail of the explosive tip assembly 22 used to convert the target-point tipped dart shown in Figure 2 into the explosive-tipped dart shown in Figure 7. The assembly includes an explosive charge 23, a charge-firing chamber 24, an inertially-activated firing pin 27 and a rear blocking insert 15b. In this example, explosive charge 23 is a 22 calibre "RamsetTM
charge" cartridge that is commonly available for powering a RamsetTM nail-gun (an explosive nail-driving tool commonly used in the construction industry). Similar 22 calibre tools are produced by Remington TM and Hilti TM . The RamsetTM charge also serves as a 22 calibre "blank" bullet that can be fired from a starter's pistol to generate a loud sharp noise.
Note that RamsetTM charges (and third-party equivalents) are freely and legally available worldwide because the charge has no lead projectile ("bullet") component which would render it part of a tightly-controlled "firearm". The 22 calibre RamsetTM charge does however have diametric dimensions that are identical to the 22 calibre bullets used in firearms. Both 22 calibre RamsetTM charges and 22 calibre bullets have a cylindrical portion (which contains the charge of smokeless powder) and a rear flange portion (which contains the rimfire primer used to ignite the charge). In both cases, the diameter of the charge portion is 0.226" (7.06 mm) and the diameter of the flange portion is 0.278" (7.06 mm).
Note also that slightly larger (25 calibre and 27 calibre) RamsetTM charges are also available.
They are typically sold in strips of charges or disks of charges for use in semi-automatic nail-guns, however each charge can be cut free of the strip or disk for individual use in the present invention. Their larger diameter does however preclude using them with the same carbon arrow tubing used in the example described above (7.8 mm OD /6.2 mm ID). Therefore, if slightly larger 25 calibre or 27 calibre charges are being used, the corresponding diameters of the dart's shaft tubing, its firing pin, its rear blocking insert and its front charge-firing chamber must also be slightly enlarged to enable the inertially-activated firing pin 27 to function properly. The 22 calibre version of the explosive tip dart embodiment is preferable, not only because the components are more readily available, but also because it allows a full-fledged 22 calibre bullet to be used in place of a RamsetTM charge (see Figure 16).
The present invention exploits the 22 calibre RamsetTM charge's flange diameter (7.06 mm) by mating the charge 23 against the front rim of a dart-shaft 14 (that tube is 7.8 mm OD and 6.2 mm ID). Since the 7.06 mm RamsetTM charge 23 is slightly too big to slide backwards into the 6.2 mm tube, charge-firing chamber 24 can thereby be fitted over the tube's 7.8 mm OD to capture and affix the charge in place. The diameter of inertially-activated firing pin 27 is 6.0 mm, thereby enabling it to slide freely inside the 6.2 mm ID shaft-tube 14.
Insert 15b is added Date Recue/Date Received 2022-07-04 to prevent the firing-pin from sliding out the rear end of the dart (Figure 10 provides greater detail on how this firing mechanism functions).
Figure 9 illustrates how the explosive-tipped dart assembly of Figure 7 can be held together using strips of adhesive tape 30. Given the magnitude of explosive force generated by detonating a RamsetTM charge, the use of tape 30 might seem inadequate.
However, the forces generated during flight, impact and post-detonation all tend to compress the firing chamber 24 further onto its seated position against shaft 14. The only separation force that chamber 24 experiences is generated by recoil of the dart backwards from the target upon detonation of its charge. Strong tape such as Gorilla Crystal Clear TM has proved to be entirely adequate for preventing separation of the assembly during recoil. Using tape is lightweight, aerodynamic and easily peeled off for either reloading a fresh RamsetTM charge or converting the dart into one of the less potent versions described above. Note that a detonated RamsetTM
charge (or a 22 calibre bullet) will be firmly lodged in its firing chamber 24. To clear the chamber for reloading a fresh charge, the user will need to force the spent brass cartridge back out through the chamber's larger diameter bore-cavity (25 in Figure 10). To facilitate extraction of the spent round, the user will typically employ a short ramrod (not illustrated) that is inserted through the front of firing chamber 24 and driven against the empty brass casing to expel it.
Figure 10 is a large-scale illustration of the explosive-tip components shown in Figure 8 (after they have been partially assembled). For clarity in the drawing, RamsetTM
charge chamber 24 and dart-shaft 14 are shown in hidden lines. The RamsetTM charge 23 is axially aligned with dart-shaft 14 and its rear flange portion is butted flush against the front rim of tubular dart-shaft 14. Ramset firing chamber 24 is typically turned from aluminum to provide adequate strength for withstanding explosive forces while minimizing the weight of dart 5 (in this drawing the chamber is turned from 1/2" diameter 6061 rod). When the firing-chamber 24 is fitted over the Ramset charge 23, its large-bore cavity 25 slides over the 7.8 mm outer dimension of dart-shaft 14 until the cavity's inner end (the lip where it transitions into the smaller-bore cavity 26) abuts against the forward side of the Ramset charge's flange portion, thereby securing the flange and charge in place. The RamsetTM charge's powder-containing portion thereby projects forward and is held within the small-bore cavity 26 of firing chamber 24. The depth of cavity 25 is chosen to leave only a small gap between the rear end of the aluminum firing chamber 24 and the front end of the plastic pin-collar 13; once the chamber is fully seated, this proximity facilitates the taping procedure shown in Figure 9. If no collar 13 is used to affix pins 12 (as shown in Figure 16) then tape can still be used to secure the firing chamber in place (by wrapping narrower strips of tape along a helical path over both the firing-chamber 24 and the forward portion of shaft 14).
In this 22 calibre example, the inertially-activated firing pin 27 is formed from 6.0 mm diameter steel rod, thereby enabling it to slide freely within the 6.2 mm bore of the tubular dart-shaft 14 described above. Inertial firing pin 27 is comprised of a massive inertial portion 28 which includes a tiny brass-piercing portion 29, which protrudes from the inertial portion's front end Date Recue/Date Received 2022-07-04 and is formed flush with its edge. The firing pin 27 is constrained from exiting the dart-shaft by insert 15b, which is affixed inside the tube's rear end. At the tube's front end, firing pin 27 is constrained by the primer-containing flange of the RamsetTM charge 23.
When dart 5 is ballistically launched, its sliding firing pin 27 is accelerated to the back of its travel and held against insert 15b during its flight to target. When the blunt front end of firing chamber 24 strikes the target, dart 5 experiences a high G-force deceleration;
this in turn causes the inertial firing-pin 27 to rapidly fly to the front end of dart-shaft 14, whereupon its brass-piercing projection 29 penetrates near the rim of the RamsetTM charge's flange portion and detonates the primer contained therein. The primer detonating in the flange rim instantly sets off the much larger volume of explosive powder contained in the RamsetTM
cartridge's main front portion (which is inside the charge-firing chamber's smaller diameter bore 26). The resulting pressure wave of hot gas exiting the charge is then channelled out the front end of firing-chamber 24 and directly onto the target.
Note that there is only a narrow band of circumferential contact area between the Ramset charge's base flange and the exposed front rim of the dart-shaft 14 (a contact band that is approximately 0.5 mm wide). This narrow rim support presents a serendipitous opportunity to drastically simplify the explosive mechanism proposed by Yuenfeng Tian's application (PCT/CN2016/000196). In order to detonate a rimfire cartridge, Tian's device requires 3 moving components (numbered 303, 309 and 304). The present invention can detonate a rimfire cartridge using only a single moving component (its firing-pin 27).
To effect that high degree of mechanical simplification, the present invention, exploits the narrow band of circular contact area between RamsetTM charge 23 and dart-shaft 14. The narrow band of rim-supporting contact exposes a large circle of unsupported area on the rear face of the RamsetTM charge's base flange. That exposed area enables the inertially-activated firing-pin 27 to directly pierce the brass flange close enough to the rim to detonate the primer contained therein. The potential problem with this simplified firing mechanism is that the unsupported center of the charge's brass casing is subjected to the full internal force generated by the main powder charge when it detonates (there is no backing plate supporting it as in the prior art). The very high internal pressure inside the detonating brass casing typically results in its unsupported rear surface deforming slightly outward into the hollow dart-shaft that supports its rim. If the internal pressure is not too great, then the deformed brass dome will withstand the force and all of the expanding gas will exit out of the crimped front end of the RamsetTM charge (and hence out the front of the charge chamber and onto the target).
If however there is too much internal pressure, the rear end of the brass casing will rupture outwards and allow some of the expanding gas to escape rearwards into the hollow dart-shaft 14. This escaping gas can cause a dangerous back-fire towards the user;
backfiring occurs if a ruptured casing permits the high-energy expanding gas to propel the firing pin 27 backwards so forcefully that it strikes the rear blocking-insert 15b hard enough that it breaks free of the dart-Date Recue/Date Received 2022-07-04 shaft. If this catastrophic failure occurs then both firing-pin and blocking-insert become projectiles that are propelled out the back of the dart and towards the user.
To prevent this dangerous condition from occurring, the blocking insert 15b must be very securely bonded to the inner wall of the tube so that any exploding gas (and potential projectiles) remain safely contained therein. Another important safety consideration is to make sure that the loaded RamsetTM charge is not so powerful as to risk rupture of the dart. Ramset charges are available in five colour-coded levels of explosive power (brown provides the lowest power level, then green, yellow, red and purple with purple providing the highest power level).
Choosing the lowest power charge that achieves the user's operational goal will make this dart embodiment less prone to casing ruptures or backfiring accidents.
To increase the destructive power of the explosive-tip dart embodiment, the user can insert a small projectile in front of the RamsetTM charge. For example, air-powered rifles are available that shoot 22 calibre lead pellets; a user might insert one of these pellets into the front portion of cavity 26 so that the lead pellet is propelled directly onto the target by the exploding Ramset charge (pellet not illustrated). Another front-loading strategy might be to glue a 177 calibre "BB"
pellet to the crimped front end of a RamsetTM charge; this configuration facilitates fast reloading.
Yet another front-loading strategy might be to mix a small amount of coarse sand with some grease to form a paste that can be inserted into the cavity; on impact the grains of sand will be propelled forward and the effect will be similar to that of a very small shotgun shell. Combining a BB pellet and some sand paste in the same front-load is yet another possibility.
Note that as soon as any front-loading occurs, the dart effectively becomes a firearm and the user must act in accordance with any local firearms and hunting regulations that might pertain to this novel weapon. Even an explosive-tipped dart with no front loading at all will still emit a high-velocity stream of hot gas directly onto its target; all variants of the dart's explosive-tipped embodiment of dart 5 can be a dangerous weapon and must be treated as such.
Also note that any obstruction that is placed in front of the RamsetTM charge (such as a pellet) will increase the back-pressure exerted onto its unsupported back end so front-loading should only be practiced with low-powered charges charges. Similarly, a standard 22 calibre bullet can be used in place of the 22 calibre Ramset charge (see Figure 16). Doing so will increase both the destructive capability of this dart embodiment and the probability that firing it will rupture the back of the cartridge as described above. To mitigate the possibility of back-pressure rupturing the bullet's base flange and possibly even the carbon dart-shaft, only low-powered, low-mass 22 calibre bullets should be used. Suitable ammunition for it are the Aquila Super Colibri, the CCI
Standard Short and the Remington Subsonic.
Exploiting the flexibility offered by various charge potencies and front-loading options allows the user to tailor their weapon for hunting various kinds of prey. For example:
when hunting squirrels or rats, the gas blast from a brown or green RamsetTM charge alone will be sufficient to kill the pest. When hunting a small feral hog, a yellow RamsetTM charge front-loaded with a BB

Date Recue/Date Received 2022-07-04 and/or sand paste will suit the task. Hunting a large buck or small moose might call for loading a purple RamsetTM charge, front-loaded with a 22 calibre lead pellet or else a low-power 22 calibre bullet. If hunting tough prey such as a large crocodile, a high-power 22 bullet such as a Winchester Magnum Rimfire might be the best dart-load for the job. Note that, while all of the above examples of the explosive-tipped dart utilize 22 calibre rimfire charges (or bullets), the scope of the invention includes slightly larger darts that are configured to carry larger calibre centerfire ammunition rounds, such as a 357 magnum cartridge (see Figure 18).
There exists a second potential danger to the user when the dart's explosive tip detonates with too much power. Whatever explosive force exits the front of the dart will produce an equal and opposite recoil force that propels the entire dart back towards the user.
Prudent users will assess the risk inherent to the charge that is loaded into their dart-tip and insure that the target is located far enough away from them that the probable recoil forces will not propel the spent dart so violently towards them that it poses a significant risk. When shooting at sufficiently remote targets, recoil forces are typically low enough that the use of protective goggles will provide adequate protection (recoiling darts tend to windmill and rapidly loose energy).
Figure 11 illustrates a simplified embodiment of dart 5 that has a solid dart-shaft 14 instead of the tubular dart-shaft used in the embodiments described above. The dart-shaft is pierced by a transverse metal rod such that protrudes equally on both sides to form the dart's pair of elastic engagement-pins 12. This simplified dart configuration addresses the safety and legal concerns that are inherent to the explosive-tipped dart shown in Figures 7 to 10. It does so because use of the solid shaft 14 precludes any possibility that an inertially-activated firing pin mechanism can be fitted to it.
By simply drilling through a sharpened wooden dowel, a metal pin can be glued in place to form the required pair of elastic engagement pins 12. Gluing two or more fletching vanes 17 onto dart-shaft 14, completes the inexpensive toy dart. Using this slingshot-launched dart is equivalent to throwing a conventional, hand-launched dart at a dartboard. To enable penetration of its relatively blunt tip, dart 5 would need to be used in conjunction with a softer dartboard than the one used with sharper, hand-thrown darts (for example, a dartboard made of Styrofoam or corrugated cardboard instead of one made of cork or dense bristles).
If instead if shooting at a dartboard, the gaming activity involves participants shooting darts at each other in mock battle, then the sharpened dowel 14 would be too dangerous.
The soft-tipped darts shown Figures 4 and 5 can however be safely used, provided the mock warriors wear safety goggles and possibly protective apparel such as might be suitable for playing hockey or paintball.
Figure 12 illustrates the solid-core dart of Figure 11 after the addition of a foam bumper-tip 20.
This dart embodiment is conceptually similar to the more complex threaded-tip version shown in Figure 5. Its solid shaft 14 provides the safety and cost savings advantages described above Date Recue/Date Received 2022-07-04 for the toy dart of Figure 11. Its sharpened tip has been fully blunted for safety by impaling a foam bumper onto the front end of the shaft and gluing it in place. As described further above for Figure 5, dusting the dart's foam tip with coloured chalk powder and/or talcum powder will enhance its utility for gaming activities.
Figure 13 illustrates the solid-core dart of Figure 11 with a broadhead tip 21 affixed to shaft 14;
its sharp-edged configuration enables the dart to be used for hunting small game. The dart is similar to the hunting dart shown in Figure 6 however, instead of having its tractor-pins 12 remote from the cutting edge of a replaceable broadhead tip, the back edge of tip 21 has rounded back edges that act as engagement-pins 12 that are integral within its triangular shape.
Figure 14 illustrates a lighter, hollow-core version of the dart shown in Figure 11. Threaded arrowhead insert 15 enables tip-interchangeability; in this illustration: a target-point tip 16, a foam gaming-tip 20 and a broadhead hunting tip 21 my be interchanged as needed to suit different usage scenarios. As with the dart shown in Figure 11, simply drilling a hole through the dart's tubular shaft 14 enables a short length of metal rod to be secured at right angles through it to form the dart's pair of elastic engagement-pins 12.
Note that the single metal rod inserted through the tubular shaft to form pins12 makes it impossible to convert this dart into an explosive-tipped version. The internally-obstructed dart embodiment is therefor well-suited for sale and use in legal jurisdictions that have very restrictive firearms legislation. In most of those jurisdictions, slingshots and archery equipment are simply treated as unregulated sporting equipment. In those jurisdictions, the non-explosive embodiments of the present invention will be no more restricted for sale or use than would be a golf club or a baseball bat. In other jurisdictions (for example in "constitutional carry" states such as Texas), the self-defence capability that comes with owning a firearm is considered a human right that "shall not be infringed". In those jurisdictions, all embodiments of the present invention are unrestricted (including the explosive-tipped embodiments).
Since this tubular-shafted dart embodiment cannot mount an explosive tip, the rear end of its dart-shaft 14 does not need to have a tube-blocking insert (see 15b in Figure 10). Omitting that blocking-insert lightens the dart, reduces its cost and moves its balance point slightly forward to improve flight characteristics. To further improve its aerodynamic behaviour, the illustrated version of dart 5 has three fletching vanes 17 (instead of only two as shown in previous examples). The additional vane adds aerodynamic drag to the rear of shaft 14, thereby further stabilizing the dart's longitudinal orientation during flight. An additional benefit of using three vanes instead of two is that the extra flight-vane can serve as a finger-grip that aids the user in pulling back forcefully on the dart prior to launch. If the three vanes are disposed evenly about the dart-shaft as illustrated, the vane furthest from the user can serve as a high-friction finger-grip. To do so, a right-handed user pinches the dart between their right-hand index finger and their right-hand thumb (the thumb griping directly onto left side of dart-shaft 14). To provide the right-side gripping surface for their index finger, the right-side (horizontally oriented) fletch vane Date Recue/Date Received 2022-07-04 is folded down and used as a grip. This gripping technique works well with glued-on vanes because they are typically made of flexible plastic that can provide a high-friction surface.
In Figure 14, a supplementary thumb-grip patch 18 has been adhered to the near-side (left-side) of dart-shaft 14. When pinched for pulling back on dart 5, this thumb-grip facilitates a secure grip; more importantly, it enables the user to sense the patch's tactile surface and rapidly identify how to orient the dart for proper engagement with elastic 4 (i.e.
engaged with pins 12 vertical and the far-side fletch laying horizontal as shown). Another sensory aid to proper dart orientation is to differentiate the colour of one of its three vanes 17. For example: if the two nearest vanes are red and furthest vane is blue, then the user can more easily orient dart 5.
Note also that this version of slingshot frame 3 includes aiming sight 31.
Aiming sight 31 is comprised of a bendable wire that enables the user to adjustably position its tip to any location between the slingshot frame's two prongs 9 and 10. To aim their Dart-launching Slingshot accurately, the user must first develop a consistent shooting posture that enables them to calibrate their aiming sight 31 and shoot with repeatable accuracy. To achieve proper shooting ergonomics, each time the user shoots a dart, they retract it to the same position adjacent their head with respect to the slingshot frame held at full arm extension.
For the right-handed user shown in Figure 1, good aiming practice (having first securely grasped both slingshot frame 3 and dart 5) is to draw back on the dart until the knuckle of their right hand thumb contacts a well-defined point on their head (such as the top of their right ear, their right cheekbone or the right corner of their mouth). Once dart 5 is positioned for launch with elastic 4 is fully tensioned, sighting the tip of aiming sight 31 onto the desired target and releasing the dart will initiate an iterative calibration process whereby the bendable wire is adjusted left/right/up/down until the dart accurately hits the target. To rapidly converge this iterative process, the user simply bends the tip of aiming sight 31 towards the location where their dart hit the target (with respect to its intended location). For example: if a calibration dart hits slightly up and to the left of the bullseye, then bending the wire so its tip also moves slightly up and to the left will improve the accuracy of the next shot.
Provided the user is consistent in their shooting posture, once sight 31 has been calibrated for a given target distance, aiming with it will result in consistent accuracy.
Since the calibration is only valid for one distance, the user must make subjective visual adjustments to maintain accuracy onto targets that are closer or farther away (aiming lower towards targets that are closer than the calibrated range and aiming higher towards targets that are farther than the calibrated range). In another embodiment of the aiming sight 31 (not illustrated), multiple bendable wires are provided instead of the single wire 31 shown protruding from slingshot-frame 3. For example, the tip of an upper wire might be calibrated for accuracy when shooting onto targets 5 metres away, a middle wire calibrated for targets 10 metres away and a lower wire calibrated for targets 20 metres away.

Date Recue/Date Received 2022-07-04 Figure 15 illustrates an embodiment that combines some of the features of both solid-core and hollow-core dart shafts. To enable RamsetTM charge 23 to be detonated by inertially-activated firing pin 27 (which must slide freely inside tubular dart-shaft 14), the pair of elastic engagement-pins 12 is comprised of separate halves that are each glued onto the outside of the shaft 14 (see Figure 16 for pin details). This split-pin strategy provides the same propulsive functionality as gluing on the plastic pin-collar 13 shown in Figure 2. It has the advantage of being somewhat lighter and more aerodynamic than using a collar with integrated pins.
Eliminating the collar also reduces the directional torquing effect (described further above) because it allows the stretched elastic 4 to lie slightly closer to the dart's centerline.
Implementing this split-pin construction strategy does however require a bond between each pin and the shaft that is strong enough to withstand the rigours of use. Using a fairly large-diameter rod to fabricate each of the dual-pins 12, and forming each one with an inner end curved that matches the outer curvature of shaft 14 will result in a sufficiently strong bond when using an epoxy or cryocyanelate glue. In addition to illustrating an explosive dart tip embodiment, Figure also shows a foam bumper-tip 20 that can be fitted to convert the dart for use in safe target games as described further above.
Figure 16 illustrates the internal components of the dart shown in Figure 15 (dart-shaft 14 is translucent to aid visualization). Dart 5 can be reconfigured to have the widest range of target impact and user applications. For clarity of how parts can be added or subtracted to reconfigure the dart, two front inserts 15 and two firing pins 27 are shown. Two pairs of glued-on tractor-pins 12 are are also illustrated to show how their externally-bonded construction keeps the interior of dart 5 unobstructed (so an inertially-activated firing pin 27 can be added that detonates either the Ramset charge 23 or the 22 calibre bullet 32).
Figure 17 illustrates a novel mechanism for affixing elastic 4 to the prongs 9 and 10 of slingshot-frame 3. It is comprised of a keyhole-shaped aperture 33 that traverses each prong near its flat tip. The aperture is aligned with the plane of the slingshot frame and includes a circular cavity portion 34 and a rectangular cavity portion 35 that opens the keyhole-shaped cavity 33 towards the front of the frame 3.
To use this novel style of clamp, each end of the elastic band 4 is folded over the top and front of each prong 9 and 10 and then folded again for insertion into the slotted front opening of the keyhole-shaped aperture 33. Once both elastic ends 4 have been fully inserted into their respect prong end, each folded band end opens to fully conform to the inner shape the keyhole-shaped cavity. The circular portion of each cavity 34 is made large enough that the elastic band will leave a space through which a slightly smaller diameter metal pin 36 can be inserted, thereby locking each end of the elastic in place. Once the pins are in place, pulling strongly on the elastic will cinch them tight and cause a clamping action that firmly and evenly grips both ends of elastic 4 across their entire width.

Date Recue/Date Received 2022-07-04 Figure 18 illustrates a centerfire embodiment of the explosive-tipped dart 5.
In this example, instead of loading a 22 calibre rimfire explosive charge, a 357 magnum bullet 37 is used instead. The four main components of the explosive mechanism are: the centerfire bullet 37, the centerfire inertially-activated firing pin 38, the linking collar to the dart's shaft 39 and the jacket that contains the bullet 40. As a visual aid, those four main parts (37, 38, 39 and 40) are shown both assembled into dart 5 (with hidden lines to reveal internal structure) as well as duplicated and roughly aligned above the Dart-launching Slingshot 1.
Like the 22 calibre firing chamber 25 described above, linking collar 39 must withstand large explosive forces so it is typically turned from aluminum. It is typically side-drilled at 42 so that the dart's pair of elastic engagement pins 12 can be bonded in place as shown.
Linking collar 39 has a large diameter front socket 26 (sized to receive bullet-jacket 40) and a smaller diameter rear socket 25 (sized to receive the front end of dart-shaft tube 14). The wall of material between the linking collar's front and rear sockets includes a central aperture 43 that is sized to enable the central detonating pin 29 protruding from the inertially-activated firing pin 38 to reach through and puncture the primer of centerfire bullet 37. The 357 magnum bullet 37 includes a protruding rear flange that enables it to be secured into the front socket 26 of linking collar 39. To secure the bullet in place, the user first slides their bullet 37 into the linking collar's front aperture 26 until it's rear flange is fully seated; its centerfire primer will be adjacent the forward opening of firing-pin aperture 43. The user then slides bullet-jacket 40 over the exposed portion of bullet 37 and inserts it all the way into front socket 26;
it will seat against the front side of the bullet's rear flange to hold it in place. To complete the loading procedure and render dart 5 ready to launch, strips of tape can then be used to secure jacket 40 to collar 39 (as described above and shown in Figure 9). Note that bullet-jacket 40 must be able to withstand the large radial forces generated by detonating bullet 37 so it is typically formed of robust metal tubing such as stainless steel.
Two styles of this centerfire exploding-tip embodiment are proposed. The configuration described above can in theory be reloaded however in practice, the highly destructive nature of the charge might easily destroy the dart, particularly if a larger bullet is used (for example using a 44 Colt bullet instead of the illustrated 357 magnum bullet). To mitigate that danger, a smaller round (such as a 38 special) might be used however there would still be a danger posed to the user due to the entire dart recoiling towards them in response to the heavy lead bullet being projected forward on impact.
To deal with that danger, a second style of explosive tip can be configured using the same components that are shown in Figure 18. Instead of allowing the bullet to freely fire its lead projectile forward out the dart's front end "muzzle" (as it would in a conventional firearm), the dart tip is modified to at least partially block the lead projectile from exiting the front of metal jacket 40. The goal of blocking the jacket's front opening is to provoke a catastrophic failure of both the bullet's brass casing and its surrounding metal of jacket 40.
Rupturing the side of the dart-tip will greatly lessen the amount of explosive energy used to propel the bullet's lead Date Recue/Date Received 2022-07-04 projectile onto the target and thereby reduce the dart's recoil towards the user. Furthermore, rupturing the entire front end of the dart will project high-speed shrapnel radially from the point of impact on the target.
To effectively block the bullet projectile inside steel jacket 40 and provoke its catastrophic rupture, the user can apply a generous coating of epoxy glue while sliding jacket 40 over bullet 37 and inserting it into linking collar 39. The length of jacket 40 projects far enough forward that it forms a trough around the bullet's curved front end; epoxy glue that accumulates and hardens inside this circular trough will effectively block the bullet from exiting the front of dart 5. When detonated, the sealed explosive inside bullet 37 will cause jacket 40 and the front portion of its surrounding collar 39 to explode like a fragmentation grenade. Detonation occurs on impact when pin 29 is violently forced through aperture 43 by inertially-activated firing pin 38. To increase the fragmentation effect of the dart's exploding tip, a grid of partial rupture-fractures may be machined into the surface of both jacket 40 and linking collar 39 (not illustrated). This network of pre-weakened fault lines is functionally equivalent to the "pineapple" texture seen on grenades that are hand-thrown by soldiers in battle.
In military ordnance terms, this embodiment of the Dart-launching Slingshot functions quite like a miniature grenade launcher. By converting some of the explosive charge's energy into laterally-projected shrapnel at the target, it protects the user to some extent from dart recoil (even at fairly close range). It therefore has the potential to become a useful military weapon:
for example, commandos operating behind enemy lines might use it to engage hostile personnel. Alternatively, the ability to accurately shoot small fragmentation grenades with a slingshot might be used to destroy strategic communication infrastructure such as an electrical power-grid transformer or antennae on an enemy communication tower.
Figure 19 illustrates an embodiment of dart-launcher 1 having an elastic band component 4 that uses a centrally located string portion 46 to propulsively engage the band's elastic portions 44 and 45 onto projecting tractor-pins 49 of dart 5. Once engaged, the string's narrow engagement path is very similar to that of the continuous elastic's path shown in Figure 3. To improve both the durability and force geometry of elastic band 4, its central string portion 46 is formed by a short length of robust string material (such as high-strength braided fishing line). Each string-end is affixed to it respective elastic band portion, 44 and 45, at fixation joints 47 and 48.
Fixation joints 47 and 48 are typically effected using a simple "clove-hitch"
style of knot; the knotted string is tightened around each elastic portion 44 and 45 to compress their rear end of the (typically tapered) latex band into a gathered narrow end that is securely bonded to the string; the harder the user pulls on the joint, the tighter and more secure it becomes. Note that as joints 47 and 48 are tightened onto each flat band, their latex material will fold onto itself and bunch together to form a shape that is somewhat similar to the pointed end of a canoe (not illustrated in Figure 19).

Date Recue/Date Received 2022-07-04 The illustrated version of slingshot frame 3 uses glue to affix each front end of elastic 4 to the frame's prong portions 9 and 10. To effect a strong bond that optimizes compactness and propulsion geometry, the front portions of elastic portions 44 and 45 are folded around the front corners of prongs 9 and 10 where a short length of it is glued to each prong's front face, typically using a fast-drying cryocyanelate adhesive. The band can be glued flat onto the slingshot frame prongs at 9 and 10 as shown in Figure 19. Alternatively, the front end of the tapered band can be cut twice as wide as shown, folded longitudinally onto itself and then glued so that it too forms a "canoe-shaped" front end (it being larger but similar in shape to the smaller string-tied rear end described above). The folded front end of each canoe-shaped elastic portion 44 and 45 can then be glued onto frame 3 in the same manner used for gluing the flat bands shown in Figure 19.
This folded-band technique of forming elastic potions 44 and 45 provides a larger volume of latex into which a user can store energy as they retract a dart in preparation for each shot.
Attaching both canoe-shaped elastics 44 and 45 to prongs 9 and 10 with their concave sides facing inwards helps insure that the band's string portion 46 will disengage cleanly from the tractor-pins 49 on dart 5. This operational feature occurs because, as the tensioned elastic is released and starts to become flaccid, the constrained canoe-shaped elastic starts to expand outward to carry the string away from the departing dart. This anti-string-fouling feature adds to the inherent safety provided by the present invention's drive asymmetry that biases the dart's glide path away from the user's hand (as illustrated in Figure 3 and described further above).
To optimize propulsive engagement of string 46 onto dart 5, the dart's pair of engagement pins 49 are formed using a single small-diameter metal pin that pierces tubular shaft 14 to project just far enough to reliably engage the thin string (which engages onto and around the pins and dart-shaft in the same manner as the much wider latex band shown in Figure 3).
To optimize the illustrated dart 5 for use with a wooden dartboard (shown as 57 in Figure 22), dart-shaft 14 mounts screw-tip 52. Screw-tip 52 is a coarse-threaded wood-screw that enables the dart to embed firmly into a wooden dartboard target yet be easily removed (simply by turning the embedded dart counter-clockwise, using the pins for leverage). The smooth-tipped, notch-sided darts of the prior art embed so firmly into wood that they typically require pliers to remove.
The dart's shaft 14 also mounts optional gripping surface 58, thereby enabling the user to more ergonomically pull back on the dart during the energizing and aiming phase of each shot (see gripping pad 18 in Figure 2). A pair of glued-on "off the shelf arrow fletching vanes 50 form a plane that is inline with the axis of launching pins 49, thereby insuring that the vertically oriented dart vanes fly though the narrow space 59 without colliding with any portion of slingshot frame 3.
Note that (in contrast to the slingshot frame 3 shown in Figure 2), this embodiment of slingshot frame 3 is ambidextrous (due to the vertically symmetric finger-griping indentations on its hand-grip portion 8).

Date Recue/Date Received 2022-07-04 The illustrated embodiment of slingshot frame 3 also has a plurality of sighting marks 54 that aid the user to aim each shot; while not as adjustable in both horizontal and vertical directions as the aiming wire 31 shown in Figure 14, the horizontal marks 54 provide useful visual reference for elevating the aiming of shots for targets at various distances. Figure 19 also shows one or more quiver-holes 55 that can be used to conveniently store one or more darts on the slingshot frame (by inserting their screw-tip 52). One or more slingshot frame cutouts 53 may also be provided to facilitate storage of elastic band 4 when not in use. To store the band, both elastic portions of the band 4 are wound through a cutout, then around the top of the frame at 59 and finally secured for storage by hooking the string portion 46 over the frame's pointed end.
Figure 20 illustrates an embodiment of slingshot frame 3 that has a shape which, (compared to the corresponding frame in Figure 19), provides extra dart fly-by clearance at 59. The added clearance is needed to allow an axially spinning dart 5 to fly past the dart-launcher without any possibility of its fletching vanes 50 or their angled winglets 51 contacting the frame. The deeper clearance cutout 59 does however limit the number of extra darts that can be carried in quiver-holes 55 (in this example the integral quiver's carrying capacity is reduced from five darts to two). To accommodate the need for users to carry more darts than the quiver holes 55 allow, while darts are being stored in the user's pocket, close-fitting foam rubber scabbards may be used to render their sharp tip 52 harmless (scabbards not illustrated).
Figure 20 shows an embodiment of aiming marks 54 which is comprised of dotted lines; they further aid the user to visualize a matrix of aiming points that compensate for both elevation and windage errors. To impart axial spin to dart-shaft 14, each fletching vane 50 includes an angled winglet portion 51; as the dart advances, airflow onto each winglet 51 rotates shaft 14, thereby averaging out aerodynamic imbalances and improving accuracy. The illustrated winglets 51 are angled to impart clockwise rotation, thereby aiding threaded tip 52 to better embed in a target.
In the illustrated example, elastic engagement pins 49 are comprised of a single metal pin mounted to shaft 14 through a hole that is slightly offset from the dart's axis. Offsetting the pins to the right of the dart's the central plane (for a right-hand user) enables the tensioned string 46 shown in Figure 19 to wrap around the pins and pull directly along the dart's axis. If offset pins are used, then left-handed and right-handed users need to be mindful of rotating the dart so the pins are furthest away from them before engaging them onto elastic 4. To help remind the user of this orientation requirement, a conspicuous mark can be made on one of the fletch vanes, thereby visually prompting the user to always engage the dart with the correct orientation.
Both of these pin configurations have advantages and disadvantages. Direct axial pulling on the dart's offset pins 49 is more accurate because it eliminates the slight torquing error that is described further above (and which provides a safety feature with respect to the prior art's tendency to steer the dart towards the user's hand). The disadvantage of offsetting the pins 49 is that it creates a slight aerodynamic asymmetry that causes the dart to wobble slightly along its glide path (hence the advantage of spinning the shaft during flight). The pin 49 is typically Date Recue/Date Received 2022-07-04 held in place using epoxy glue, which can simultaneously affix screw-tip 52 in place as shown (typically abutted against the transverse pin inside of shaft 14). To add forward-balancing weight to the dart (for improved flight characteristics), the gluing process may also affix a short length of metal rod inside of shaft14 (located immediately behind pins 49).
Figure 21 is an exploded view of a dart embodiment that utilizes a monolithic vane 50 mounted in slot 61 to shaft 14, thereby separating it into two aerodynamically functional fletching vanes.
The monolithic pair of vanes 50 is typically cut from a sheet of rigid plastic such as poly-carbonate and its winglets 51 are then bent to an angle that imparts rifled travel to dart 5. Dart-shaft 14 is drilled for pins 49 and slotted through 61 to enable the vanes/winglets component to be glued in place as shown. The illustrated shaft 14 includes a roughened portion 58 that serves as a high-friction gripping surface in place of glued-on friction pads.
Fishing embodiments The vane/winglet structure 50, 51 may also include a central rear tab 64 with a fishing line attachment hole 65, thereby enabling the dart-launcher to be used for a modified form of bowfishing. To configure dart 5 for use as a fish-catching device, its screw-tip 52 (optimized for dartboard gaming) is replaced with a commonly available "bowfishing" arrow tip (similar to the "broadhead" tip 21 in Figure 14 that is used for hunting terrestrial game).
Unlike the broadhead tip, the bowfishing tip (not illustrated) has sharp folding side-points that open to act as one-way fish hooks once the tip has been impaled into a fish. To enable use of a standard bowfishing tip, a standard arrow insert is glued into the front end of shaft 14 (in place of screw-tip 52). A
typical threaded arrow shaft insert is shown at 15 in Figure 14. The insert can also be used to mount other types of threaded archery tips, such as the target point 16 shown in Figure 14.
The rear end of this "bowfishing" version of dart 5 is attached to the end of a fishing line that is spooled into a conventional fishing reel. A fishing reel with a spool cowling, (such as the Zebco 404 or 202) works best for this application because the reel's bulbous main body can be easily grasped in one hand while its spooling-crank is turned by the other hand.
To use this fishing apparatus (for a right-handed user), the fishing reel component is first suspended by a short lanyard so that it hangs from the user's left wrist. The wrist-lanyard attaches to the base of the fishing reel so that it hangs upside-down and facing forward; in this attitude it can either hang freely (with its fishing line free to spool out forward) or swung up and be firmly grasped in the user's left hand (able to be cranked by their right hand). The user then grasps the dart-launcher in their left and uses their right hand to engage the line-tethered dart onto the dart-launcher's elastic band.
To insure that the tethered dart launches correctly and spool out its attached fishing line freely as the dart flies away, the user must make sure to back the tethered dart through the loop of the elastic before engaging its pins 49; this insures that as that dart exits the launcher its attached fishing line has an unimpeded path towards the hanging reel. Once it has been engaged in this Date Recue/Date Received 2022-07-04 manner and drawn back to its tensioned launch position, the user can then aim and fire their bowfishing dart into a targeted fish. Once the fish is impaled, the user's freed right hand is used to quickly transfer and hang the flaccid elastic of the dart-launcher over their right forearm (thereby freeing the left hand). With both hands free, the user then swings up the hanging fishing reel and firmly grasps it in their freed left hand. Their freed right hand is then used to reel-in and land the impaled fish.
Using the bowfishing embodiment to impale fish is a challenging sport; it requires very accurate shooting skills as well as skill at compensating for the refraction error inherent to aiming at fish.
A much easier mode of catching fish with the dart-launching slingshot is to utilize a variant of the bowfishing arrow tip that carries a conventional fishhook and bait. The angler uses this apparatus in much the same way a regular rod and reel are used; the baited hook is launched out over the water and then reeled in to troll for fish. An effective configuration for this "fish-trolling" tip is comprised of the shaft of a conventional J-shaped fishhook affixed to the front end of dart-shaft 14, in place of the illustrated screw-tip 52 (hook not illustrated). The J-shaped hook's barbed end points back towards the dart so (once bait has been impaled onto it), the dart can be cast over and into the water using the dart-launcher and fishing reel (as described above for the bowfishing tip), thereby emulating the action of an angler casting a baited hook into the water with their fishing rod. This "fish-trolling" embodiment typically enables the user to cast and troll their baited hook further away from them than when using a conventional fishing rod. It also gives them the option of switching to bowfishing mode if and when they encounter a fish that is a suitably visible target.
Dartboard embodiment Figure 22 illustrates the invention's dartboard gaming embodiment. User 2 is one of two or more players participating in a game of skill by shooting dart 5 at dartboard 56 with their dart-launching slingshot 1. Each player takes turns shooting three darts at numbered sectors marked on dartboard 56 and scoring their efforts in accordance with well-known dartboard gaming rules. In its preferred embodiment, each dart 5 is configured with a wood-screw tip (as shown in Figures 19 and 20), thereby enabling the game to proceed using a wood-backed playing surface; each played dart embeds its tip firmly in wooden panel 57, which underlies the printed dartboard graphic 56. Each played dart can be easily removed from the dartboard (by turning the dart counterclockwise); once removed, it leaves a small neat hole in the graphic that facilitates scoring each player's performance. To further facilitate game-scoring, each player's allotment of darts may carry a unique colour scheme. This gaming embodiment of the Dart-launching Slingshot can be easily and safely used indoors because the darts reliably adhere to the dartboard; if attempted with a conventional slingshot there would be ricocheting projectiles bouncing off walls and causing havoc.
In its preferred embodiment, the dartboard game is comprised of a set of kit components which the user completes using locally-purchased lumber. The basic, two-player dartboard-game kit is a compact, low-cost and easily shipped package that contains: two dart-launchers, six darts and Date Recue/Date Received 2022-07-04 a printed dartboard graphic. To complete and assemble their dartboard game, the user 2 purchases a suitably-sized panel of wood 57 at a local building supply store and adheres the printed graphic 56 onto it.
Prolonged gaming will eventually erode the dartboard's surface to the point where scoring becomes ambiguous or the screw-tipped darts start bouncing out of its wood backing. To enable the user to refurbish their dartboard economically, a digital copy of the dartboard graphic 56 can be made freely available online; to accommodate the small letter-sized paper format of household computer printers, the dartboard distributed graphic is typically formatted as four letter-sized sheets that print out the four dartboard quadrants onto paper.
The user trims and mosaics together the four sheets and then adheres the graphic onto the wooden panel using glue or a transparent packing tape wrapping. If the panel is too eroded for effective gaming then its surface can be smoothed using drywall compound or a new panel purchased locally.
The completed dartboard 56, 57 may be hung onto a wall of the user's residence or, optionally, be held on a freestanding easel 66 that they also configure using locally-purchased lumber.
This compact, easily-shipped kit configuration of the dartboard gaming embodiment results in a far lower cost to end-users than if a ready-to-use dartboard were included in the package. The resulting cost-effectiveness aides in promoting widespread adoption of the new sport.
Safety is an important factor when distributing the dartboard gaming embodiment as a recreational product. To promote safe use, the kit's packaging should urge the new user to take a free online video training course and notify them that, by purchasing this product, they agree to use it strictly as shown in the instructional videos. Any deviation from that intended use constitutes misuse of the product, for which the user is solely responsible.
Legal precedent and common practice regarding sporting goods support that type of legal disclaimer and liability protection for the manufacturer. For example, golf clubs, baseball bats, hockey sticks and billiard cues are all designed and sold for a specific sporting or gaming purpose; yet any of those products can be misused to cause bodily harm.
Traditional dartboard game sets are also potentially dangerous (particularly if used by inebriated players in a crowded pub). Similarly, a carving knife from a kitchen or a hammer from a workshop could be misused to cause mayhem; however, in legal jurisdictions worldwide, liability for any such misuse rests solely with the perpetrator.
The foregoing has constituted a description of specific embodiments showing how the invention may be applied and put into use. These embodiments are only exemplary. The invention in its broadest, and more specific aspects, is further described and defined in the claims which now follow. These claims, and the language used therein, are to be understood in terms of the variants of the invention which have been described. They are not to be restricted to such variants but are to be read as covering the full scope of the invention as is implicit within the invention and the disclosure that has been provided herein.

Date Recue/Date Received 2022-07-04

Claims (14)

Claims I claim:

1) A dart-launching slingshot comprised of:
- a roughly Y-shaped slingshot-frame having a hand-grip portion centrally-joined to first and second fixation prongs, each prong having a tip that is adapted for fixation of an elastic band, - an elastic band, affixed at one end to the slingshot-frame's first prong and affixed at its other end to the slingshot-frame's second prong, - a dart configured for secure gripping by a user of its rear, fletched portion and adapted for selectable engagement of its forward portion onto the mid-portion of the elastic band by means of an axially-aligned pair of engagement pins configured for entangled side-engagement onto the elastic band's mid-portion.

2) The slingshot of claim 1 in which the width of the elastic band is tapered inward from both ends to provide a narrower mid-portion that engages easily onto the dart's pair of axially-aligned engagement pins.

3) The slingshot of claim 1 in which the elastic band includes a mid-portion made of robust string that engages onto the dart's pair of axially-aligned engagement pins.

4) The slingshot of claim 1 in which the dart includes a tip configured as a soft bumper suitable for children's games.

5) The slingshot of claim 1 in which the dart includes a sharpened tip suitable for target practice.

6) The slingshot of claim 1 in which the dart includes a sharpened tip suitable for hunting edible game animals.

7) The slingshot of claim 1 in which the dart's shaft is tubular and includes an explosive tip mechanism comprised of an explosive charge contained within a front-mounted firing chamber, an inertially-activated firing-pin sliding within the dart's shaft and a rear shaft insert that blocks the firing-pin's rearward travel.

8) The slingshot of claim 1 in which a single pin pierces through the dart's shaft far enough to project equally out both sides and form the dart's pair of axially-aligned engagement pins.

9) The slingshot of claim 1 in which the slingshot-frame includes a sighting device for improving the accuracy of a dart's flight to its target.

10) The slingshot of claim 1 in which the slingshot-frame includes an elastic fixation mechanism near the end of each prong comprised of a keyhole-shaped aperture and an elastic fixation pin.

11) The slingshot of claim 1 in which the dart includes angled fletching winglets that impart axial spin to the dart's shaft.

12) The slingshot of claim 1 further comprising a wrist-tethered fishing reel and a fishing-line-tethered dart having a barbed tip suitable for impaling a fish.

13) The slingshot of claim 1 in which the dart includes a tip comprised of a wood-screw.

14) The slingshot of claim 1, further comprising a dartboard.