Hydraulic recoil buffer assembly

• US 20080110074A1
• Filed: 11/15/2006
• Published: 05/15/2008
• Est. Priority Date: 11/15/2006
• Status: Active Grant

• Current Assignee: Enidine Incorporated (ITT, Inc.)
• Original Assignee: Endine Incorporated
• Inventors: Johannes, Gregg F., Bucholtz, Brian C., Shurmatz, William W.
• Granted Patent: US 7,681,351 B2
• Time in Patent Office: Days
• US Class Current: 42/1.06
• CPC Class Codes: F41C 23/06 Stocks or firearm frames specially adapted for recoil reduction

Abstract

A hydraulic recoil buffer assembly for a firearm having a receiver and a fixed or collapsible stock assembly including an end cylinder adapted to be secured to the pistol grip or receiver of the firearm and slidably translatable with respect to the extension tube, and a hydraulic shock absorption assembly operative to produce a hydraulic resistance to a rearward movement of the end cylinder during recoil of the firearm. The hydraulic shock absorption assembly has an orifice restricted fluid flow passage and a piston head that compresses a return spring as the end cylinder moves rearward against a recoil coil spring. The recoil buffer assembly stores a portion of the recoil energy through compression of the recoil spring and the return spring, and dissipates a portion of the recoil energy through the resistance provided by fluid flow through the orifice restricted flow passage.

Claims

1. A recoil buffer assembly for a firearm including a receiver or pistol grip assembly and a stock assembly having an axially forward extending extension tube, said recoil buffer assembly comprising:

an end cylinder having a forward end adapted for securing to the receiver or pistol grip assembly of said firearm and an aft end slidably translatable with respect to said extension tube;

a hydraulic shock absorption assembly having an orifice restricted fluid flow passage, said hydraulic shock absorption assembly operatively associated with said end cylinder to produce a hydraulic resistance to a rearward movement of said end cylinder; and

at least one spring to provide preload and return the recoil buffer assembly to a battery position.

2. A recoil buffer assembly for a firearm as recited in claim 1 wherein the orifice restricted fluid flow passage of said hydraulic shock absorption assembly includes at least one fixed flow area orifice.

3. A recoil buffer assembly for a firearm as recited in claim 1 wherein the orifice restricted fluid flow passage of said hydraulic shock absorption assembly includes at least one adjustable flow area orifice.

4. A recoil buffer assembly for a firearm as recited in claim 1 wherein said hydraulic shock absorption assembly further includes:

a shock tube having a closed end and an open end defining an axially extending cavity;

an axially extending piston rod having a proximal end, a distal end, and a piston head associated with the proximal end of the piston rod, said piston head received within the open end of said shock tube and being axially translatable within the cavity of said shock tube, the space within the cavity of said shock tube between the closed end of said shock tube and said piston head defining a variable volume fluid chamber;

a return coil spring disposed within the cavity of said shock tube and extending between the closed end of said shock tube and said piston head;

a retaining body disposed about said piston rod and having a central axially extending bore through which said piston rod translates, said retaining body having a groove formed defining a fixed volume chamber; and

a recoil coil spring disposed about said piston rod and operatively associated with said end cylinder to resist rearward movement of said end cylinder.

5. A recoil buffer assembly for a firearm as recited in claim 1 wherein said hydraulic shock absorption assembly is disposed in the cavity of said extension tube with said shock tube positioned in a rearward portion of the cavity of said extension tube and the distal end of said piston rod connected to or in contact with the aft end of said end cylinder.

6. A recoil buffer assembly for a firearm as recited in claim 1 wherein said hydraulic shock absorption assembly is disposed in the cavity of said extension tube with said shock tube received in an axially elongated cavity within said end cylinder and the distal end of said piston rod is connected to or in contact with an end plug body disposed within a rearward portion of the cavity of said extension tube.

7. A recoil buffer assembly for a firearm as recited in claim 1 wherein said recoil buffer assembly is integral with said extension tube.

8. A recoil buffer assembly for a firearm as recited in claim 1 wherein said recoil buffer assembly is removable from said extension tube.

9. A recoil buffer assembly for a firearm as recited in claim 1 wherein said recoil buffer assembly is integral with said end cylinder.

10. A recoil buffer assembly for a firearm as recited in claim 1 wherein said recoil buffer assembly is removable from said end cylinder.

11. A recoil buffer assembly for a firearm including a receiver or pistol grip assembly and a stock assembly having an axially forward extending extension tube, said recoil buffer assembly comprising:

an end cylinder having a forward end adapted for securing to the receiver or pistol grip assembly of said firearm and an aft end slidably translatable with respect to said extension tube;

a hydraulic shock absorption assembly having a fixed volume fluid chamber, a variable volume fluid chamber, and an orifice restricted fluid flow passage connecting said variable volume fluid chamber in fluid flow communication with said fixed volume fluid chamber, said hydraulic shock absorption assembly operatively associated with said end cylinder to produce a hydraulic resistance to a rearward movement of said end cylinder; and

at least one spring to provide preload and return the recoil buffer assembly to a battery position.

12. A recoil buffer assembly for a firearm as recited in claim 11 wherein said hydraulic shock absorption assembly further includes:

a shock tube having a closed end and an open end defining an axially extending cavity;

an axially extending piston rod having a proximal end, a distal end, and a piston head associated with the proximal end of the piston rod, said piston head received within the open end of said shock tube and being axially translatable within the cavity of said shock tube, the space within the cavity of said shock tube between the closed end of said shock tube and said piston head defining said variable volume fluid chamber;

a return coil spring disposed within the cavity of said shock tube and extending between the closed end of said shock tube and said piston head;

a retaining body disposed about said piston rod and having a central axially extending bore through which said piston rod translates, said retaining body having a groove formed therein defining said fixed volume chamber; and

a recoil coil spring disposed about said piston rod and operatively associated with said end cylinder to resist rearward movement of said end cylinder.

13. A recoil buffer assembly for a firearm as recited in claim 11 wherein said hydraulic shock absorption assembly is disposed in the cavity of said extension tube with said shock tube positioned in a rearward portion of the cavity of said extension tube and the distal end of said piston rod connected to or in contact with the aft end of said end cylinder.

14. A recoil buffer assembly for a firearm as recited in claim 13 wherein the orifice restricted fluid flow passage of said hydraulic shock absorption assembly includes at least one adjustable flow area orifice.

15. A recoil buffer assembly for a firearm as recited in claim 11 wherein said hydraulic shock absorption assembly is disposed in the cavity of said extension tube with said shock tube received in an axially elongated cavity within said end cylinder and the distal end of said piston rod is connected to or in contact with an end plug body disposed within a rearward portion of the cavity of said extension tube.

16. A recoil buffer assembly for a firearm as recited in claim 15 wherein the orifice restricted fluid flow passage of said hydraulic shock absorption assembly includes at least one fixed flow area orifice.

17. A firearm including a receiver or pistol grip assembly, a stock assembly having an axially forward extending extension tube, and a recoil buffer assembly, characterized in that said recoil buffer assembly comprises:

an end cylinder having a forward end adapted for securing to the receiver or pistol grip assembly of said firearm and an aft end slidably translatable with respect to said extension tube;

a hydraulic shock absorption assembly having an orifice restricted fluid flow passage, said hydraulic shock absorption assembly operatively associated with said end cylinder to produce a hydraulic resistance to a rearward movement of said end cylinder; and

at least one spring to provide preload and return the recoil buffer assembly to a battery position.

18. A firearm as recited in claim 17 wherein the orifice restricted fluid flow passage of said hydraulic shock absorption assembly includes at least one fixed flow area orifice.

19. A firearm as recited in claim 17 wherein the orifice restricted fluid flow passage of said hydraulic shock absorption assembly includes at least one adjustable flow area orifice.