# US 2014/0155200 A1 · Multi-pellet launcher with selectable choke

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- Number: US 2014/0155200 A1
- Document ID: US20140155200A1
- Status: Published application
- Kind: A1
- Application number: 13/890,053
- Filed: 2013-05-08
- Published: 2014-06-05
- Earliest claimed: 2011-11-16
- Inventors: G. Wilson Flint
- Web page: https://patentgrep.com/patent/US20140155200A1

## CPC

- F42B 12/362: {Arrows or darts (F42B12/38 takes precedence, having means for implantation, e.g. hypodermic projectiles F42B12/54; arrows or darts in general F42B6/00)}
- F41B 7/02: the spring forming part of the missile or projectile
- F42B 12/56: for dispensing discrete solid bodies (F42B12/70 takes precedence)
- Y10T 29/49826: Assembling or joining
- F42B: EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION (explosive compositions C06B; fuzes F42C; blasting F42D)
- F41B: WEAPONS FOR PROJECTING MISSILES WITHOUT USE OF EXPLOSIVE OR COMBUSTIBLE PROPELLANT CHARGE; WEAPONS NOT OTHERWISE PROVIDED FOR (projectiles for fishing, e.g. fish-spears, A01K81/00; sports implements for throwing A63B65/00, e.g. boomerangs A63B65/08; stationary apparatus for projecting sports balls, e.g. tennis balls, A63B69/40; throwing or slinging toys A63H33/18; knives, axes B26B; projectiles or missiles other than those incorporating springs as projecting means F42B6/00)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## 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.

## Claims

### Claim 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 “to”, 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 “to+τ”.

### Claim 2 (depends on 1)

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 “to” with a response force equal to “kΔx”.

### Claim 3 (depends on 1)

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

### Claim 4 (depends on 1)

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

### Claim 5 (depends on 1)

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

### Claim 6 (depends on 1)

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

### Claim 7 (depends on 1)

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.

### Claim 8 (depends on 1)

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”.

### Claim 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 “vf”, 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 “vf”;
a pellet propulsion unit mounted on the launch tube for an in-flight activation of the pellet propulsion unit at a time “to”, to propel the plurality of pellets in a distal direction at a propulsion velocity “vp” 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 “to”, to attain a muzzle velocity “vm” for the pellets, where vm=vf+vp.

### Claim 10 (depends on 9)

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:
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 “to” with a response force equal to “kΔx”.

### Claim 11 (depends on 10)

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

### Claim 12 (depends on 9)

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

### Claim 13 (depends on 9)

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

### Claim 14 (depends on 9)

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

### Claim 15 (depends on 9)

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”.

### Claim 16 (depends on 9)

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.

### Claim 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 “to”.

### Claim 18 (depends on 17)

A method as recited in claim 17 further comprising the steps of:
identifying an operational muzzle velocity “vm” for the pellets, wherein “vm” equals the sum of a flight velocity “vf” of the launch tube and a propulsion velocity “vp” for the pellets during the time interval “τ” inside the lumen of the launch tube (vm=vf+vp); and
selecting values for the variables “x”, “k”, “n” and “L” to achieve the required “vp”.

### Claim 19 (depends on 18)

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 “vm,” is in a range between 340-370 fps.

### Claim 20 (depends on 18)

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