# US 10,502,511 B2 · 3-cycle 2-stroke damper

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- Number: US 10,502,511 B2
- Document ID: US10502511B2
- Status: Granted
- Kind: B2
- Application number: 15/959,427
- Filed: 2018-04-23
- Published: 2018-10-25
- Granted: 2019-12-10
- Earliest claimed: 2017-04-24
- Applicants: Thomas Allen Graves
- Inventors: Thomas Allen Graves
- Web page: https://patentgrep.com/patent/US10502511B2

## CPC

- F41A 3/94: in combination with spring buffers
- F16F 13/007: {the damper being a fluid damper}
- F41C 3/00: Pistols, e.g. revolvers (specially adapted for underwater use F41C9/06; for slaughtering or stunning animals A22B; for shooting bolts into concrete constructions, metal walls or the like B25C)
- F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F41C: SMALLARMS, e.g. PISTOLS, RIFLES (functional features or details common to both smallarms and ordnance, mountings therefor F41A; projecting missiles without use of explosive or combustible propellant charge F41B); ACCESSORIES THEREFOR

## Abstract

A trigger activated arm may use a piston moving within a cylinder to dampen gun bolt speed. In some embodiments, gun bolt motion increases pressure within the cylinder bore to dampen rearward gun bolt speed. The pressure may be high enough to unseat the cylinder creating a vent that cylinder fluid exits. In other embodiments, gun bolt motion decreases pressure within the cylinder bore to dampen forward gun bolt speed.

## Claims

### Claim 1

An arm comprising:
a frame;
a trigger that is depressible to fire the arm once per operating cycle;
a gun bolt that is movable rearward and forward with respect to the frame;
a surface supported to the frame;
a piston supported to one of the gun bolt and the surface;
a cylinder that: 1) defines a cylinder bore; 2) has cylinder fluid within the cylinder bore; and, 3) is supported to the other of the gun bolt and the surface; and,
a biasing device that biases the gun bolt forward;
wherein on firing the arm, the arm is operable to:
1) move the gun bolt rearward to cause the piston to move with respect to the cylinder to: (a) compress the cylinder fluid within the cylinder bore to dampen rearward gun bolt speed; and then (b) move the cylinder with respect to the other of the gun bolt and the surface to create a vent that communicates the cylinder bore to an exterior of the cylinder bore; and then (c) force cylinder fluid to exit through the vent to the exterior of the cylinder bore; and
2) move the gun bolt forward to cause the piston to move with respect to the cylinder to reduce the pressure of cylinder fluid within the cylinder bore to dampen forward gun bolt speed.

### Claim 2 (depends on 1)

The arm of claim 1 wherein:
the biasing device exerts a biasing force to hold the cylinder to the other of the gun bolt and the surface; and
moving the cylinder with respect to the other of the gun bolt and the surface overcomes the biasing force.

### Claim 3 (depends on 1)

The arm of claim 1 wherein the biasing device:
exerts a biasing force to hold the piston to the one of the gun bolt and the surface; and
exerts a biasing force to hold the cylinder to the other of the gun bolt and the surface.

### Claim 4 (depends on 1)

The arm of claim 1 wherein as the gun bolt reaches an end of a rearward stroke:
the cylinder moves with respect to the other of the gun bolt and the surface to close the vent.

### Claim 5 (depends on 1)

The arm of claim 1 wherein:
the surface lies on a bolt stop;
the piston is supported to the gun bolt;
the cylinder is supported to the bolt stop;
the bolt stop has a gun bolt contact surface; and
when the gun bolt reaches an end of a rearward stroke: the gun bolt contacts the gun bolt contact surface of the bolt stop.

### Claim 6 (depends on 1)

The arm of claim 1 wherein:
when the gun bolt moves rearward and the piston moves with respect to the cylinder to compress cylinder fluid within the cylinder bore: cylinder fluid pressure rises above atmospheric pressure; and
when the gun bolt moves forward and the piston moves with respect to the cylinder to reduce the pressure of cylinder fluid within the cylinder bore: cylinder fluid pressure falls below atmospheric pressure.

### Claim 7 (depends on 1)

The arm of claim 1 wherein the arm is operable after moving the gun bolt forward to cause the piston to move with respect to the cylinder to reduce the pressure of cylinder fluid within the cylinder bore to dampen forward gun bolt speed to:
move the piston out of contact with the cylinder bore to stop dampening forward gun bolt speed.

### Claim 8 (depends on 1)

The arm of claim 1 wherein:
the biasing device is a compression spring having a first end that contacts the gun bolt and a second end that contacts the surface.

### Claim 9 (depends on 1)

The arm of claim 1 wherein:
the biasing device is a compression spring having a perimeter;
at least a portion of the piston is positioned inside the spring perimeter; and
at least a portion of the cylinder is positioned inside the spring perimeter.

### Claim 10 (depends on 1)

The arm of claim 1 wherein:
the other of the gun bolt and the surface comprises a port;
the cylinder is supported to the other of the gun bolt and the surface with the port communicating with the cylinder bore; and
the arm is operable to move the gun bolt rearward to cause the piston to move with respect to the cylinder to: force cylinder fluid to exit through the port to an exterior of the cylinder bore.