1. Field of the Invention
The present invention relates generally to a modular fore-end rail assembly for firearms. More specifically, the present invention relates to a modular fore-end rail assembly for retrofitting a firearm that includes an upper handguard portion that is clamped around and supported by the barrel nut and further including a removable lower handguard portion that is mounted onto the upper handguard portion to fully surround the firearm barrel. The lower handguard further includes a locking mechanism to keep it assembled to the upper handguard.
2. Background of the Related Art
In the general field of combat and commercial weaponry, there is a broad range of accessories available for mounting onto standard firearms in order to upgrade the capability of these weapons. One area within the broad scope of available firearms that is of particular interest is the M16/M4 weapon system typically utilized in military or combat settings. Generally, referring to
However, prior art mounting systems often limit access to the receiver 102,104, barrel 108 and barrel nut 110 assembly. This situation is undesirable because it limits servicing of the weapon 100 to qualified weapon smiths with appropriate tools and setting, e.g. an armory.
Accordingly, there is a need for a modular fore-end rail assembly for mounting accessories to a firearm 100 that supports the accessories that allows the lower handguard to be quickly detachable from the upper handguard. There is a further need for a modular fore-end rail assembly that provides an easily removal portion that allows access to the barrel 108 of the firearm 100 without having to remove the entire assembly from the firearm that is operable using only a single hand. Finally, there is a further need for a modular fore-end rail assembly that can be mounted to a firearm that derives its structural support entirely from the upper receiver 104 of the firearm 100 while not requiring the replacement of modification of the existing barrel nut 110, yet still retains an easily removable portion for servicing the barrel 108.
In this regard, the present invention provides for modular fore-end rail assembly that is mounted onto a firearm that serves both as a handguard system and as an integrated interface system for mounting attachments thereto. The present invention is particularly directed to an improved modular fore-end rail assembly that includes a locking mechanism to enable quick detachment of the lower handguard or lower firearm accessory for access to the barrel without requiring the removal of the entire assembly from the firearm. The modular fore-end rail assembly further provides for a lower handguard that may be easily removed with a single hand. Further, by providing for the easy removal of the lower handguard, other auxiliary devices may be mounted to the upper handguard. For example, an M203 grenade launcher can be mounted to the upper handguard in place of the lower handguard portion.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:
Referring now to
The upper handguard portion 12 is the structural element that supports the entire modular assembly 10. The upper handguard portion 12 is formed generally as the upper half of a tubular enclosure that is configured to encircle the barrel of the firearm when in a mounted position. The upper handguard portion 12 has a forward end 18 and a rearward end 20 and a standard dovetail rail 22 extending longitudinally between the forward end 16 and the rearward end 18. The upper handguard portion 12 has left and right side walls 24, 26 that extend generally outwardly and downwardly from the dovetail rail 22 forming the upper half of the tubular enclosure. The left and right side walls 24, 26 each have an interior and exterior surface and the walls 24, 26 each terminate at their lower ends with additional dovetail rail interfaces 28, 30 extending along the exterior surface thereof and a channel formation 32 on the interior surface thereof, best seen in
A clamping assembly 16 is provided at the rearward end portion 20 of the upper handguard portion 12 in order secure the upper handguard portion 12 to the firearm. Generally, the clamping assembly 16 includes a clamp 35 configured to cooperate with the rearward end portion 20 of the upper handguard portion 12 to engage the existing barrel nut on the fire arm and serves to support the entire assembly by engaging the barrel nut. The clamp 35 has a central semi-circular recess 36 therein and flanges 37 extending out to each side thereof. The clamp 35 is attached to the rearward end portion 20 of the upper handguard portion 12 with fasteners 38 that are inserted through openings 40 in the flanges 37 on the clamp 35 and into threaded holes 42 in the side walls 24, 26 of the upper handguard portion 12. When the fasteners 38 are installed and tightened, the clamping assembly 16 is drawn to the upper handguard portion 12 and the two components cooperate to engage the barrel nut as well as the serrated flange on the end of the barrel nut. This mounting configuration allows the clamp 35 and upper handguard portion 12 to be mounted rigidly onto the firearm while deriving all of the required structural support from the front of the upper receiver and barrel nut and eliminating any need to engage the barrel of the firearm. All of the weight of the modular fore-end rail assembly 10 and accessories that are mounted thereto is transferred effectively to the upper receiver thereby protecting the barrel from any additional transfer of load or shock.
Further, while fasteners 38 are shown extending through the clamping assembly 16 and into the upper handguard portion 12, it should be appreciated that the fasteners 38 could also extend from the upper handguard portion 12 and into the clamping assembly 16 and still fall within the disclosure of the present invention.
The clamping assembly 16 also includes a sliding locking pin 44 received in a locking pin channel 72 to engage an aperture 46 on the lower handguard portion 14 as will be described in detail below.
When the upper handguard portion 12 is assembled with the upper receiver, the dovetail rail of the upper handguard portion 12 is arranged so that it extends forwardly in linear alignment with the dovetail rail of the upper receiver to form a continuous rail extending over the barrel.
The lower handguard portion 14 is formed in a semi-circular shape that is complimentary to the upper handguard portion 12 and completes a tubular enclosure around the barrel of the firearm when the lower handguard portion 14 is mounted to the upper handguard portion 12. The lower handguard portion 14 generally includes a longitudinal rail interface 48 extending from a front end portion 50 to a rear end portion 52. The lower handguard portion 14 has side walls 54, 56 that generally extend upwardly and outwardly therefrom and terminate in mating formations 58 or mounting tabs that are shaped and configured to engage the channels 32 along the bottom edges of the sidewalls 24, 26 of the upper handguard portion 12. The lower handguard portion 14 is therefore slidably engaged with the upper handguard portion 12. Further, the rear end of the lower handguard portion includes a key way 60 with an aperture 46 that is shaped to engage the locking pin 44 on the clamping assembly 16 to lend additional stability and structural integrity when the entire assembly 10 is installed on a firearm. The locking pin 44 is provided to allow the clamping assembly 16 to engage the aperture 46 on the lower handguard portion 14 and prevent it from being accidentally dislodged from the upper handguard portion 12. When a user wishes to remove the lower handguard portion 14, the locking pin 44 is moved clear of the aperture 46 and the lower handguard portion 14 is slid forward to disengage it from the upper handguard portion 12 as shown in
The locking pin 44 is retained in the locking pin channel 72 of the clamping assembly 16 by a spring-biased retaining pin 62, best seen in
Therefore, it can be seen that the present invention provides a unique solution to the problem of providing a modular fore-end rail assembly for mounting accessories to a firearm that supports the accessories that allows the lower handguard to be quickly detachable from the upper handguard. The modular fore-end rail assembly also provides an easily removable portion that allows access to the barrel of the firearm without having to remove the entire assembly from the firearm that is operable using only a single hand. Finally, the modular fore-end rail assembly can be mounted to a firearm and is structurally supported entirely from the upper receiver of the firearm while not requiring the replacement of modification of the existing barrel nut, yet still retains an easily removable portion for servicing the barrel.
It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be within the scope of the present invention.
The present patent document claims priority to earlier filed U.S. Provisional Patent Application Ser. No. 61/022,627, filed on Jan. 22, 2008, the entire contents of which are incorporated herein by reference.
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