US20140155200A1

US20140155200A1 - Multi-pellet launcher with selectable choke

Info

Publication number: US20140155200A1
Application number: US13/890,053
Authority: US
Inventors: G. Wilson Flint
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-11-16
Filing date: 2013-05-08
Publication date: 2014-06-05

Abstract

A system and method for propelling pellets from a launch tube includes a retainer plug for holding the pellets inside the launch tube between the retainer plug and a compressed spring. A latch is established on the launch tube to restrain forward movement of the retainer ring in response to the bias force imposed by the compressed spring. In operation, the launch tube is propelled in a forward direction by a man-powered weapon to further compress the spring and release the latch from the retainer plug. After the initial acceleration has subsided, force from the compressed spring provides a forward propulsion of the retainer plug and the plurality of pellets from the launch tube for travel of the pellets toward an intended target. As an added feature, the launch tube can be extended to delay separation of the pellets from the tube for a so-called “choke” effect.

Description

This application is a continuation-in-part of application Ser. No. 13/298,124, filed Nov. 16, 2011, which is currently pending. The contents of application Ser. No. 13/298,124 are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention pertains generally to man-powered weapons. More particularly, the present invention pertains to systems and methods for shooting a plurality of pellets (i.e. projectiles or shot) at a target with a statistically predictable and defined shot group on the target. The present invention is particularly, but not exclusively, useful as a system and method for propelling a multi-pellet-filled launch tube from a man-powered weapon, and for employing the resultant acceleration force on the launch tube to unlatch and release the pellets from the launch tube for impact in a shot group on a target.

BACKGROUND OF THE INVENTION

Typically, man-powered weapons are designed to launch only one projectile at a time. In particular, this is the case when the weapon is to be operated and fired by a single individual. For example, the arrow of a well-known bow and arrow set is such a projectile, as is the bolt of a crossbow or the dart of a blowgun. There are instances, however (e.g. the extermination of vermin or clay pigeon shooting), when it would be preferable to simultaneously launch several projectiles (e.g. pellets) all at the same time. In this respect, there is a need for a man-powered weapon that is comparable in its on-target effect to the familiar shotgun. To achieve such comparability with a man-powered weapon, like a shotgun, all of the pellets need to be collectively launched as a predictably defined group. The situation for a man-powered weapon is exacerbated, however, due to the fact that they typically employ only a single launching string or, in the case of an air gun, a single launching tube.
Ideally, when a plurality of projectiles are to be launched simultaneously from a single man-powered weapon, the launching mechanism of the weapon needs to have comparably direct influence upon each projectile (e.g. pellet). Specifically, the influence and control over each projectile in the plurality must be similar, and be effective to the same extent, as if only one projectile was being launched. It happens, however, that with a single string or single barrel launcher (e.g. a bow, a crossbow or an air gun), such influence and control is virtually impossible. A solution for this problem is to, somehow, structurally combine the several projectiles into a cohesive unit for launch. This solution, of course, must be short term. Immediately after launch, the problem then becomes how to effectively separate the projectiles. Specifically, this separation must be accomplished in a manner that causes the projectiles to travel toward a target in a predictably defined group that will have the intended on-target effect.
As is well known in the shotgun sports, it is often desirable to reconfigure a shotgun to extend the on-target effect of the shot group further down range than is otherwise possible. To do this, the shot pattern is effectively compressed as it is being fired from the shotgun. Typically, a so-called “choke” is provided for this purpose. If used, the “choke” is selectively attached to the barrel of the shotgun to physically constrict the bore of the shotgun barrel at its extreme distal end. This then causes the shot to start with a tighter group integrity as it leaves the barrel, before traveling further down range. This same effect, for essentially the same reasons, may also be desirable when using man-powered weapons to launch a plurality of pellets along a flight path.
With the above in mind, it is an object of the present invention to provide a multi-pellet launcher that will hold a plurality of projectiles together as a single cohesive unit prior to and during launch. Another object of the present invention is to provide a multi-pellet launcher that will maintain a group integrity for the pellets (projectiles) while in flight, for the purposes of achieving an intended on-target effect (i.e. have a statistically well defined shot group). Yet another object of the present invention is to delay the dispersal of pellets (projectiles) that are shot from a launch tube, until a predetermined time after launch, to thereby effectively “choke” the pellets and extend the intended on-target effect further down range. Still another object of the present invention is to provide a multi-pellet launcher that is easy to use, is simple to manufacture, and is cost effective.

SUMMARY OF THE INVENTION

In accordance with the present invention, a system is provided for propelling pellets (projectiles) from a launch tube. In particular, the propulsion of pellets occurs after the launch tube has been shot from a man-powered weapon (e.g. a bow, a crossbow or an air gun). Prior to being shot (launched), the launch tube holds a plurality of pellets inside the tube. Specifically, this is accomplished by positioning the pellets between a retainer plug that is restrained inside the launch tube, and a compression spring that is fixedly mounted inside the launch tube. In order to restrain the retainer plug, a latch is established relative to the launch tube. The latch then prevents a forward movement of the retainer plug, and the pellets, in response to a bias force that is imposed on the retainer plug and the pellets by the partially compressed spring.
In overview, while the launch tube is being propelled in a forward direction by a man-powered weapon, the resultant acceleration force on the launch tube moves the retainer plug and pellets in a relatively rearward (proximal) direction with respect to the tube. This proximal movement of the retainer plug and pellets in the launch tube further compresses the spring, and simultaneously releases the latch from the retainer plug. In flight, after the initial acceleration force has subsided, the compressed spring provides a forward propulsion force on the plurality of pellets and the retainer plug. This propulsion force then ejects the pellets and the retainer plug from the launch tube. The pellets then continue on toward an intended target.
Structurally, the launch tube of the present invention is formed with a lumen, and it defines a longitudinal axis. In a preferred embodiment of the present invention, it also has an open distal end and a closed or partially closed proximal end. Beginning at the proximal end of the lumen inside the launch tube, the spring is positioned and affixed to its closed proximal end. The plurality of pellets (projectiles) is then positioned in the lumen against the spring. Next, the retainer plug is positioned in the lumen distal to the plurality of pellets (projectiles). In greater structural detail, for one embodiment of the present invention, the retainer plug has a distal ring that is dimensioned to move within the lumen, and it has a proximal ring that is also dimensioned to move within the lumen. Between these rings of the retainer ring is a mid-section that is formed with a decreasing taper in the proximal direction.
In the vicinity of the retainer plug, the sidewall of the launch tube is formed with one or more lateral vents. Preferably, these vents are located equidistant from the distal end of the tube. One or more latch spheres are provided to interact between the proximal ring of the retainer plug and the vents of the launch tube. Specifically, this interaction is in response to the distally directed force that is generated when the spring is partially compressed. More specifically, each latch sphere is trapped in a respective vent, and it is urged against a distal edge of the vent by the proximal ring of the retainer plug. Thus, prior to a launch, the distal bias of the compressed spring on the retainer plug holds the retainer plug, and the pellets, stationary in the lumen of the launch tube.
Upon shooting a launch tube from a man-powered weapon, an acceleration force is imposed in a distal direction on the pellets, and on the proximal end of the spring within the lumen of the launch tube. This acceleration causes the retainer plug and pellets to move proximally relative to the launch tube, and the spring is further compressed. In turn, this relative motion of the retainer plug and launch tube causes the proximal ring of the retainer plug to release the latch sphere(s) and causes a tapered or stepped region of the retainer plug to eject the latch sphere(s) from the launch tube through their respective vents. Consequently, the retainer plug and the plurality of pellets are released by the latch and are propelled from the launch tube in response to the distal bias of the spring.
An additional structure of the launch tube is an inner sleeve that can be affixed inside the lumen of the launch tube, proximal to the spring. Specifically, this inner sleeve is positioned at a distance “d_f” from the distal end of the launch tube to act as an abutment for the spring when it is compressed. The distance “d_f” can, of course, be varied as desired. In any event, it is preferable that the inner sleeve be affixed to place the pellets (projectiles) relatively near the distal end of the launch tube. With this in mind, the present invention envisions that, even though the pellets may extend through a relatively short distance (i.e. a few inches), an inner sleeve will allow the total length of the launch tube to be as long as is required for a conventional bow, compound bow or crossbow.
For a preferred embodiment of the present invention, there may be as many as forty or more pellets, and they can be made of steel. Also, in order to promote tumbling of the retainer plug after a launch of the launcher, the distal ring of the retainer plug may be formed with a distal recessed surface, and is made of a light-weight material such as Acrilonitrile-Butadiene-Styrene (ABS), Polycarbonate or Polysulfone. Also, for the purpose of dispensing the pellets in-flight for a controlled, on-target impact, the pellets inside the launch tube can be combined with a plurality of spacers. If used, individual spacers can be positioned between adjacent pellets in the launch tube. In another embodiment, for the same purpose, a plurality of magnets can be combined with the pellets in a configuration where adjacent magnets straddle two pellets, and pellets on opposed sides of a same magnet are subjected to a different polarity.
For an alternate embodiment of a latch for the multi-pellet launcher, the launch tube is formed with a pair of axially opposed slots that extend, parallel to each other, in a proximal direction from the distal end of the launch tube. A detent is formed at the proximal end of each slot. For this embodiment, the retainer plug is cylindrical and includes a pair of axially opposed pins that extend outwardly from the retainer plug. For an assembly of the multi-pellet launcher in accordance with this alternate embodiment, the pins on the retainer plug are received in a respective slot of the launch tube and are advanced in a proximal direction. When the pins are at the proximal end of their respective slots, the retainer plug is rotated to engage the pins with a respective detent at the end of the slot. This holds the retainer plug stationary in the launch tube. Upon a subsequent launching of the launch tube, the resultant acceleration force rotates the pins out of their detents. This then frees the retainer plug for axial movement out of the launch tube in a distal direction when the acceleration force subsides. It is an important consideration for this particular embodiment of the latch, that the pins do not extend beyond the outer diameter of the launch tube when the retainer plug is engaged with the launch tube. This is necessary to allow an assembled launcher to be received within the barrel of a weapon (e.g. an air gun) without any interference of the pins on the retainer plug with the bore of the barrel.
In yet another embodiment of a latch for the present invention, the launch tube is formed with at least one lateral opening. For this embodiment, the retainer plug includes a clip that is mounted on the retainer plug, and the clip is reconfigured to engage with the lateral opening. Importantly, the clip does not extend beyond the lateral opening. When the launch tube is launched, as in the other embodiments of the present invention, the resultant acceleration force moves the retainer plug in a proximal direction relative to the launch tube. Consequently, the clip is released from the lateral opening. The retainer plug is thereby released for free travel through the launch tube.
For another aspect of the present invention, a launch tube is provided that delays the separation of pellets from the launch tube for a time interval “τ”, after the time of launch “t_o”. Structurally, this is accomplished by providing the launch tube with a distal extension of a length “L”. Thus, with the extended launch tube, the plurality of pellets are propelled inside the launch tube, through the length “L”, for an additional time interval “τ”, after launch. An important consideration here is that at the time of pellet separation (i.e. “t_o+τ”) the launch tube will already be traveling along a flight path at a flight velocity “v_f”. In order to help provide in-flight aerodynamic stability for the launch tube during the time interval “τ”, a plurality of vanes can be externally mounted adjacent the proximal end of the launch tube. As disclosed above for other embodiments of this invention, the flight velocity “v_f” results from the impulse force that is exerted by the launcher on the launch tube when it is launched at the time “t_o”. Thus, this impulse force not only accelerates the launch tube to flight velocity “v_f”, it also simultaneously activates the binary latch to release the pellets for separation from the launch tube. In addition to the flight velocity “v_f”, it is also necessary to consider the velocity of the pellets “v_p” inside the launch tube during the time interval “τ”. In line with earlier disclosure, it will be appreciated that this velocity “v_p” results from the action of the spring that is mounted inside the launch tube. Consequently, at the time of pellet separation, there are two important factors to be considered. For one, the launch tube will have already traveled down range through a distance substantially equal to “(v_f)(τ)”. For another, the muzzle velocity “v_m” will equal the sum of the flight velocity “v_f” and the pellet velocity “v_p” inside the launch tube (v_m=v_f+v_p).
Insofar as metrics for the extended launch tube are concerned, the launch tube extension length “L” will preferably be in a range between four and ten inches. Also, the time interval “τ” for pellet travel in the launch tube, prior to separation, will preferably be in a range between 50-100 msec. And further, the resultant muzzle velocity “v_m” of the pellets at separation from the launch tube will preferably be in a range between 340-370 fps.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is a side elevation view of a multi-pellet launcher in accordance with the present invention;

FIG. 2A is a perspective view of a launcher of the present invention during mid-launch from a crossbow;

FIG. 2B is a plan/elevation view of the launcher of the present invention prepared for launch from a bow;

FIG. 3 is a plan/elevation view of an air gun for use with the present invention;

FIG. 4A is a cross-section view of the multi-pellet launcher as seen along the line 4-4 in FIG. 1 prior to launch;

FIG. 4B is a cross-section view of the multi-pellet launcher as seen in FIG. 4A as the launcher is being accelerated during launch;

FIG. 4C is a cross-section view of the multi-pellet launcher as seen in FIG. 4B after launch;

FIG. 5 is a cross-section view of an alternate embodiment of a multi-pellet launcher as would be seen along the line 4-4 in FIG. 1;

FIG. 6 is a cross-section view of another embodiment of the multi-pellet launcher as seen along the line 4-4 in FIG. 1;

FIG. 7A is an exploded perspective view of an alternate embodiment of a launch tube and retainer plug for use with the present invention, with the retainer plug positioned for engagement with the launch tube;

FIG. 7B is a view as shown in FIG. 7A with the retainer plug engaged with the launch tube;

FIG. 8A is a cross-section view of a launcher as seen along the line 8-8 in FIG. 7A prior to a launch;

FIG. 8B is a cross-section view of the launcher shown in FIG. 8A, immediately after a launch;

FIG. 8C is a front-on view looking into the launch tube of the launcher;

FIG. 8D is a cross-section view of an alternate embodiment for the inner sleeve shown in FIG. 8A, prior to launch;

FIG. 8E is a cross-section view of the inner sleeve shown in FIG. 8D, immediately after launch;

FIG. 9A is a cross-section view of another alternate embodiment of a launch tube and retainer plug prior to a launch;

FIG. 9B is a cross-section view of the launch tube shown in FIG. 9A immediately after a launch;

FIG. 10 is a perspective view of a spring guide for use with the spring in an alternate embodiment of the present invention;

FIG. 11A is a cross sectional view of a launcher using a spring guide, as seen along the line 8-8 in FIG. 7A, prior to launch;

FIG. 11B is a view of the launcher shown in FIG. 11A immediately after launch; and

FIG. 12 is a schematic presentation of a launcher tube with a tube extension, showing a sequence of pellet locations relative to the tube during flight, beginning at launch and continuing through separation of the pellets from the launch tube.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1, a multi-pellet launcher in accordance with the present invention is shown and is generally designated 10. As shown, the launcher 10 includes a hollow, elongated launch tube 12 that has a distal end 14 and a proximal end 16. For the launcher 10, the distal end 14 of launch tube 12 is open, and its proximal end 16 is closed or partially closed. For purposes of disclosure, the launch tube 12 defines a longitudinal axis 18 that extends between the distal end 14 and the proximal end 16. As intended for the present invention, the launcher 10 can be used as a bolt for a crossbow 20 (see FIG. 2A), as an arrow for a bow 22 (see FIG. 2B) or as a launch tube 12 to be used with an air gun 23 and launched from its barrel 25 (see FIG. 3). In all important respects, the multi-pellet launcher 10 will be essentially the same regardless of the type of man-powered weapon that is to be used (i.e. crossbow 20, bow 22 or air gun 23).
Referring now to FIG. 4A, a launcher 10 is shown in greater detail to include a nock 24 at its proximal end 16 and a flight stabilizer 26 that will stabilize the launch tube 12 during its flight. Other structural aspects of the launcher 10 are discussed with reference to the lumen 28 of the launch tube 12, and begin with an inner sleeve 30 that is fixedly attached to the launch tube 12, inside the lumen 28. Referring for the moment back to FIG. 1, it will be seen that the inner sleeve 30 is positioned in the lumen 28 of the launch tube 12 at a distance “d_f” from the distal end 14 of the launch tube 12. FIG. 1 also indicates that the inner sleeve 30 is positioned at a distance “d_a” from the proximal end 16 of the launch tube 12.
FIG. 4A also shows that a spring 32 is positioned in the lumen 28 immediately distal the inner sleeve 30, and between the inner sleeve 30 and a plurality of pellets 34. As intended for the launcher 10, there may be six or more pellets 34. The pellets 34 shown in the drawings are only exemplary. It will be appreciated that the distance “d_f” will depend primarily on the number of pellets 34 that are to be used. On the other hand, the distance “d_a” may vary considerably, depending on the type of man-powered weapon to be used. As envisioned for the present invention, the overall length of the launcher 10 (i.e. d_f+d_a) may be as long as twenty nine or thirty inches.
Positioned distal to the pellets 34 is a retainer plug 36 that is preferably made of a light weight material such as Acrilonitrile-Butadiene-Styrene (ABS), Polycarbonate or Polysulfone. Structurally, the retainer plug 36 is formed with a proximal ring 38 and a distal ring 40, with a mid-section 42 formed therebetween. Importantly, both the proximal ring 38 and the distal ring 40 are dimensioned for movement within the lumen 28 of the launch tube 12. Further, it is important that the mid-section 42 be formed with a decreasing taper in the proximal direction from the distal ring 40 to the proximal ring 38.
As perhaps best seen in FIG. 4B, the launch tube 12 is formed with one or more vents 44. In FIG. 4B, the vents 44 a and 44 b are only exemplary, as there may be more vents 44 if desired. Both FIGS. 4A and 4B, however, show that each vent 44 interacts with a respective latch sphere 46. Again, like the vents 44 a and 44 b, the latch spheres 46 a and 46 b are only exemplary.
Despite the number of vents 44 and latch spheres 46 that may be used, it is to be appreciated that each latch sphere 46 interacts individually with the retainer plug 36 and with its respective vent 44. Importantly, the purpose of these interactions is to hold the pellets 34 in the lumen 28 of the launch tube 12 prior to a launch. Specifically, FIG. 4A shows that prior to a launch, each of the latch spheres 46 is trapped (wedged) between the proximal ring 38 of the retainer plug 36 and the forward (distal) edge of a vent 44. This structural interaction changes dramatically with a launch of the launch tube 12.
As a launch tube 12 is launched from a crossbow 20, or bow 22, in the direction of arrow 47 (see FIG. 4B) an acceleration force is generated that will cause the retainer plug 36 and the plurality of pellets 34 to move in a proximal direction inside the lumen 28 of the launch tube 12. With this movement, several things happen. For one, the spring 32 is further compressed. For another, as the retainer plug 36 moves in the proximal direction, the proximal ring 38 of retainer plug 36 disengages from the latch spheres 46. As this happens, the tapered mid-section 42 of the retainer plug 36 ejects the latch spheres 46 away from the launch tube 12, through their respective vents 44. A consequence of this is that both the retainer plug 36 and the pellets 34 are no longer confined in the lumen 28 of the launch tube 12.
Shortly after launch, in accordance with well known principles, the initial acceleration force on the launch tube 12 subsides. With this diminution of the acceleration force, the potential energy in the compressed spring 32 is released to propel the retainer plug 36 and pellets 34 from the launch tube 12. As shown in FIG. 4C, after being propelled from the launch tube 12 by the spring 32, the retainer plug 36 separates and tumbles away from the pellets 34. To assist in this separation and tumbling behavior, the distal face 48 of retainer plug 36 can be formed with a recessed (concave) surface. In any event, the desired result is that the plurality of pellets 34 will then follow a planned trajectory toward a target (not shown), for an intended on-target affect. An important consideration here is that the pellets 34 need to also achieve a degree of separation from each other for the creation of the desired on-target shot group.
For an alternate embodiment of the launcher 10, as shown in FIG. 5, a plurality of spacers 50 can be employed to help with the separation of pellets 34 after launch. The spacers 50 a and 50 b shown in FIG. 5 are exemplary. If used, the spacers 50 will typically be positioned to straddle each pellet 34 in a manner such as is shown for the spacers 50 a and 50 b. Preferably, the spacers 50 will be made of a light weight material such as felt or paper. In another alternate embodiment of the launcher 10 for this same purpose, as shown in FIG. 6, a plurality of magnets 52 can be employed. In this embodiment, a pair of magnets ( e.g. magnets 52 a and 52 b) will straddle a pair of pellets ( e.g. pellets 34 a and 34 b). For best effect, within this structure, the opposed sides of the magnets 52 a and 52 b will have the same polarity. Thus, the magnets 52 ( magnets 52 a and 52 b are exemplary) will add a repelling force on the pellets 34 a and 34 b that will influence their separation in flight.
An alternate embodiment for the structure of a latch to be used with the present invention is shown in FIGS. 7A & 7B. In FIG. 7A it will be seen that a launch tube 54 has a proximal end 56 and a distal end 58, with a pair of opposed parallel slots 60 a and 60 b that extends in a proximal direction from the distal end 58. Further, with reference to the slot 60 a in FIG. 7A, it is seen that the end of the slot 60 a is formed with a detent 62, and an angled edge 64 extends in a proximal direction therefrom. FIG. 7A also shows a cylindrical shaped retainer plug 66 that includes a pin 68 which extends outwardly from the plug 66. Actually, there is a pair of opposed pins 68 (one is not shown). With reference to FIG. 7B, it will be appreciated that during an assembly of the retainer plug 66 with the launch tube 54, the pin(s) 68 is(are) inserted into the respective slots 60 a and 60 b. They are advanced through the slots 60 a and 60 b, and the retainer plug 66 is then rotated to seat the pin(s) 68 against the detent(s) 62.
In an operation of the launch tube 54, the acceleration force that initially results during a launch of the launch tube 54 will cause the retainer plug 66 to move in a rearward (proximal) direction relative to the launch tube 54. This relative movement of the retainer plug 66 then causes the pin 68 to follow the angled edge 64. The result here is that the retainer plug 66 is rotated to realign the pin 68 with the slot 60 a, and to thereby allow for a free distal (forward) movement of the retainer plug 66 out of the launch tube 54 when the acceleration force subsides. An important aspect of this particular embodiment of a latching action for the present invention is that the pin(s) 68 do not extend beyond the outer surface 70 of the launch tube 54. This is so in order to allow for an assembled launch tube 54 to be positioned in a hollow launch tube (not shown), such as in the barrel of an air gun 23. Additionally, it will be appreciated by the skilled artisan that the inside surface 72 of the barrel 25 of air gun 23 can be rifled to assist in the proper rotation and alignment of the retainer plug 66 during an operation of this embodiment of the present invention.
FIG. 8A shows an alternate configuration for components inside the launch tube 12/54. One component of interest is the inner sleeve 74. As shown, the inner sleeve 74 is positioned inside the launch tube 12/54, and is preferably located at or near the proximal end 56. Further, the inner sleeve 74 includes an abutment 76 that establishes a hollow 78 for the inner sleeve 74. Within this structure, the spring 32 is positioned between the abutment 76 and a washer 80. Importantly, when so positioned, a portion of the spring 32 will be inside the hollow 78. Thus, as shown in FIG. 8B, when the spring 32 is compressed by a force of acceleration (represented by arrow 82 in FIG. 8B), compression of the spring 32 is controlled. Specifically, during a launch of the launch tube 12/54, the compression of spring 32 will be limited by the constraints imposed on it by dimensions of the hollow 78 inside the inner sleeve 74. FIGS. 8A and 8B also indicate that the abutment 76 of the inner sleeve 74 can be formed with an opening 84. Opening 84, however, is optional. Indeed, when the launch tube 54 is to be used with an air gun (not shown), it is preferable that the opening 84 be closed.
Still referring to FIGS. 8A and 8B, an arrangement for stacking pellets 34 (e.g. pellets 34 c-f) within a launch tube 12/54 is shown. In detail, by cross referencing FIG. 8B with FIG. 8C, a stacking arrangement for a relatively large number of the pellets 34 (e.g. thirty or more pellets 34) is shown. In particular, this stacking arrangement is possible when each of the pellets 34 has a diameter “d_p” that is slightly less than half the inner diameter “d_i” of the launch tube 12/54 (see FIG. 8C). For purposes of disclosure, specific reference is made to pellets 34 c, 34 d, 34 e and 34 f (only pellets 34 c, 34 d and 34 f are shown in FIG. 8B). With FIGS. 8B and 8C, it will be appreciated that the pellets 34 c and 34 e are essentially positioned inside the launch tube 12/54, side-by-side. Likewise, the pellets 34 d and 34 f are also side-by-side. In order to easily achieve this stacking configuration during loading, the pellets 34c-f can be introduced into the launcher tube 12/54 in pairs ( e.g. pellets 34 d and 34 f together, and then pellets 34 c and 34 e).
FIG. 8D shows a two-part alternative structure for the inner sleeve 74 that was disclosed above and is shown in FIG. 8A. Specifically, for this embodiment, a distal inner sleeve 74′ and associated abutment 76′ are shown in axial alignment with the inner sleeve 74 and its abutment 76. For both embodiments, the object is to control compression of the spring 32 (compare FIG. 8E with FIG. 8B).
Referring now to FIGS. 9A and 9B, yet another embodiment of a latching mechanism for the launcher 10 of the present invention is shown. In this embodiment, the launch tube 12/54 is formed with at least one lateral opening 86, and a clip 88 is mounted on a cylindrical shaped retainer plug 90. When the retainer plug 90 and its clip 88 are positioned in the lumen 28 of a launch tube 12/54, and the clip 88 is received in the lateral opening 86 of the launch tube 12 (see FIG. 9A), the clip 88 will hold the retainer plug 90 stationary in the launch tube 12/54. Specifically, this will be in response to forces imposed on the retainer plug 90 by a spring 32 (not shown in FIGS. 9A and 9B). Importantly, the clip 88 will not extend beyond the lateral opening 86. As with the other latching embodiments for the present invention, the retainer plug 90 is acceleration activated. Thus, in response to the acceleration force of a launch, the retainer plug 90 moves in a proximal (rearward) direction. This then frees the clip 88 from the lateral opening 86 for subsequent free travel of the retainer plug 90 through the launch tube 12/54 along with the propulsion of pellets 34 a (et. seq.) from the launch tube 12/54.
In yet another configuration for components inside the launch tube 12/54, a spring guide 92 is employed to control and restrict compression of the spring 32. As shown in FIG. 10, the spring guide 92 includes a base 94 and an extension 96 which projects from the base 94. A through hole 98 is formed in the spring guide 92, and this through hole 98 extends through both the base 94 and the extension 96. Preferably, the spring guide 92 is made of a rigid, light-weight material such as polycarbonate.
FIGS. 11A and 11B show how a spring guide 92 is employed by the present invention. First, in FIG. 11A, it will be seen that a pair of spring guides 92 are used with the spring 32. Specifically, there is a distal spring guide 92 a and a proximal spring guide 92 b that are respectively engaged with opposite ends of the spring 32. As shown in FIG. 11A, both of the spring guides 92 a and 92 b are positioned in the launch tube 12/54 with their respective extensions 96 inserted into the center space of spring 32. Further, the base 94 of distal spring guide 92 a is positioned against the pellet(s) 34, and the base 94 of proximal spring guide 92 b is positioned against the abutment 76 at the proximal end 56 of the launch tube 12/54. As shown in FIG. 11A, the configuration of the spring 32 with the spring guides 92 a and 92 b is prior to a launch. After launch, the spring 32 is compressed substantially as shown in FIG. 11B by the acceleration force of the launch. Importantly, this compression of spring 32 is limited during an acceleration by the contact that occurs between the extension 96 of spring guide 92 a and the extension 96 of spring guide 92 b. A consequence of this is that the spring guides 92 a and 92 b help prevent a fouling of the spring 32 during its operation.
In another aspect of the present invention, a specially configured launch tube 100 is shown in FIG. 12. Specifically, the launch tube 100 is similar in all important structural aspects to the launch tubes 12/54 disclosed above. The exception for launch tube 100 being the structural extension 102 of the lumen 28 that projects in a distal direction from the retainer plug 36 through the distance “L”. In detail, the distance “L” is measured in a proximal direction from the distal end 104 of the launch tube 100. The distance “L” thus extends from distal end 104 to the location of the binary latch (represented by retainer plug 36) which holds the pellets 34 stationary inside the lumen 28 of launch tube 100 prior to the launch time “t_o”. Operationally, the effect of this extension 102 is to provide a so-called “choke” for the plurality of pellets 34 that are to be employed with the launch tube 100.
In FIG. 12, the launch tube 100 is sequentially shown in three configurations. First, it is shown at the time of launch “t_o”. As disclosed above, this configuration is maintained prior to an activation of the binary latch (represented in FIG. 12 by the retainer plug 36). In this configuration, the pellets 34 are held stationary in the lumen 28 of launch tube 100. Next, the launch tube 100′ is shown in flight. Specifically, the launch tube 100′ is shown during the time interval between the time of launch “t_o” and a time “τ” when the pellets 34 are separated from the launch tube 100. It is to be understood that during this time interval from “t_o” to “τ” (i.e. time interval “τ”), the pellets 34 move in a distal direction through the lumen 28 of launch tube 100. Moreover, due to the force imparted by spring 32 on the pellets 34 when the latch (i.e. retainer plug 36) is activated, the pellets 34 move at a relative velocity “v_p” inside the launch tube 100′. After being launched, however, the launch tube 100′ is also moving at a flight velocity “v_f”. Accordingly, directional vanes 108 can be provided to help in a stabilized flight of the launch tube 100′ until after the pellets 34 have been separated from the launch tube 100′. Finally, the launch tube 100″ is shown at the time “τ” as the pellets 34 separate from the launch tube 100″ for continued travel along the flight path 106 toward a target (not shown). The consequence of all this is that the pellets 34 will have an effective muzzle velocity “v_m” which is the sum of “v_f” and “v_p” (v_m=v_f+v_p). Preferably, the muzzle velocity “v_m” will be in a range between 340-370 fps at the time “t_o+τ”.
While the particular Multi-Pellet Launcher with Selectable Choke as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.

Claims

What is claimed is:

1. A multi-pellet launcher which comprises:

an elongated hollow tube formed with a lumen and having a proximal end and an open distal end;

an abutment affixed to the proximal end of the tube;

a plurality of pellets positioned inside the lumen and aligned therein to extend in a proximal direction from a location measured at a distance “L” from the distal end of the tube; and

a pellet propulsion unit mounted on the tube and configured therewith for activation thereof in response to an impulse force exerted in a distal direction on the proximal end of the launcher at a time “t_o”, to move the pellets in a distal direction through the distance “L” and to expel the pellets from the distal end of the tube at a time “t_o+τ”.

2. A multi-pellet launcher as recited in claim 1 wherein the pellet propulsion unit comprises:

a spring positioned in the lumen of the tube between the abutment and the pellets, wherein the spring has a relaxed length “x” and a spring constant “k”; and

an acceleration activated binary latch configured to interact with the tube to compress the spring through a distance “Δx” and to hold the pellets stationary in the tube prior to “t_o” with a response force equal to “kΔx”.

3. A multi-pellet launcher as recited in claim 1 wherein “L” is in a range between four and ten inches.

4. A multi-pellet launcher as recited in claim 1 wherein “τ” is in a range between 50-100 msec.

5. A multi-pellet launcher as recited in claim 1 wherein the pellets have a velocity in a range between 340-370 fps at time “t_o+τ”.

6. A multi-pellet launcher as recited in claim 1 wherein the plurality of pellets includes between six and eighteen pellets.

7. A multi-pellet launcher as recited in claim 1 wherein the length “L” is provided by an extension of the tube, and the extension of the tube is selectively integrated with the tube.

8. A multi-pellet launcher as recited in claim 1 further comprising a plurality of vanes externally mounted on the tube, adjacent the proximal end thereof, to extend outwardly from the tube to provide additional aerodynamic stability for the launcher during the time interval “τ”.

9. A system for launching a plurality of pellets from a multi-pellet launcher, as the launcher travels along a flight path at a flight velocity “v_f”, the launcher comprising:

a launch tube formed with a lumen and having a proximal end and an open distal end;

a means for firing the launch tube onto the flight path with the flight velocity “v_f”;

a pellet propulsion unit mounted on the launch tube for an in-flight activation of the pellet propulsion unit at a time “t_o”, to propel the plurality of pellets in a distal direction at a propulsion velocity “v_p” through the lumen of the launch tube; and

a launch tube extension having a length “L”, wherein the launch tube extension is integrated with the launch tube to continue movement of the plurality of propelled pellets inside the launch tube, through the length “L”, for an additional time interval “τ” immediately after the launch activation time “t_o”, to attain a muzzle velocity “v_m” for the pellets, where v_m=v_f+v_p.

10. A system as recited in claim 9 wherein an abutment is affixed to the proximal end of the tube and the pellet propulsion unit comprises:

11. A system as recited in claim 10 wherein the firing means exerts an impulse force on the launch tube at time “t_o” to accelerate the launch tube to flight velocity “v_f”, and to activate the pellet propulsion unit.

12. A system as recited in claim 9 wherein “L” is in a range between four and ten inches.

13. A system as recited in claim 9 wherein “τ” is in a range between 50-100 msec.

14. A system as recited in claim 9 wherein the muzzle velocity “v_m” is in a range between 340-370 fps.

15. A system as recited in claim 9 further comprising a plurality of vanes externally mounted on the tube, adjacent the proximal end thereof, to extend outwardly from the tube to provide additional aerodynamic stability for the launcher during the time interval “τ”.

16. A system as recited in claim 9 wherein the means for firing the launch tube is selected from a group comprising a conventional bow, a compound bow, a crossbow, and an air gun.

17. A method for assembling a multi-pellet launcher which comprises the steps of:

providing a launch tube formed with a lumen and having a proximal end and an open distal end, with an abutment affixed to the proximal end of the tube;

selecting a spring having a relaxed length “x” and a spring constant “k”;

positioning the spring inside the lumen of the tube against the abutment at the proximal end thereof;

deciding upon an “n” number of pellets;

aligning the “n” number of pellets in the lumen of the launch tube, distal to the spring; and

configuring an acceleration-activated binary latch with the launch tube at a distance “L” from the distal end of the launch tube, to hold the pellets between the latch and the spring, and to compress the spring through a distance “Δx” to generate a spring force equal to “kΔx” for propelling the pellets through the distance “L” within a time interval “τ”, in response to an activation of the binary latch at a time “t_o”.

18. A method as recited in claim 17 further comprising the steps of:

identifying an operational muzzle velocity “v_m” for the pellets, wherein “v_m” equals the sum of a flight velocity “v_f” of the launch tube and a propulsion velocity “v_p” for the pellets during the time interval “τ” inside the lumen of the launch tube (v_m=v_f+v_p); and

selecting values for the variables “x”, “k”, “n” and “L” to achieve the required “v_p”.

19. A method as recited in claim 18 wherein “L” is in a range between four and ten inches, wherein “τ” is in a range between 50-100 msec, and wherein the muzzle velocity “v_m,” is in a range between 340-370 fps.

20. A method as recited in claim 18 wherein “v_f” results from the application of an impulse force on the launch tube at the time “t_o”.