Split compression piston

Patent metadata

Field	Value
Publication number	US-9562738-B2
Application number	US-201414148409-A
Country	US
Kind code	B2
Filing date	Jan 6, 2014
Priority date	May 10, 2013
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

In a spring piston airgun, a compression piston is provided for longitudinal translation within a compression tube in response to a motive force. The compression piston includes a main piston body and a piston head, wherein the piston body and piston head are coupled for partial independent translation along a longitudinal axis. A resilient compressible bushing is longitudinally intermediate a portion of the piston body and the piston head, such that upon a deceleration of the piston head, the piston body is not immediately acted upon by the deceleration, rather the bushing absorbs a portion of the deceleration and radially expands to contact the compression tube.

First claim

What is claimed is:

1. An airgun comprising:
(a) a barrel;
(b) a compression tube having transfer port fluidly connected to the barrel;
(c) a compression piston at partially disposed within the compression tube and moveable within the compression tube between a first position and a second position, the compression piston having a piston body and a piston head, the piston head being longitudinally displaceable relative to the piston body during movement from the first position to the second position;
(d) a seal connected to the piston head and forming a sealed interface with an inside surface of the compression tube;
(e) a spring contacting the compression piston, the spring repeatably moveable between a cocked position and a fired position, wherein the compression piston is in the first position in the cocked position of the spring and the compression piston is in the second position in the fired position of the spring; and
(f) a radially expandable bushing connected to the piston body, the bushing radially expanding from a non contacting configuration to a contacting configuration in response to a longitudinal compressive force on the bushing, the longitudinal compressive force corresponding to movement of the spring from the cocked position to the fired position and the radial expansion of the bushing in the contacting configuration sufficient to contact the inside surface of the compression tube.

2. The airgun of claim 1 , further comprising a plurality of tail guides extending radially from the compression piston, the plurality of tail guides contacting an inside surface of the compression tube.

3. The airgun of claim 1 , wherein the spring is a gas spring having a gas spring body defining a sealed interior chamber containing a compressed gas and a gas spring piston extending into and moveable relative to the sealed interior chamber, the interior chamber retaining the compressed gas when the gas spring piston moves.

4. The airgun of claim 1 , wherein the bushing and the piston body define engaging surfaces, and the surfaces are non-perpendicular to the longitudinal axis.

5. An airgun comprising:
(a) a compression tube;
(b) a compression piston slideably received within the compression tube, the compression piston having a piston body and a piston head, the compression piston moveable between a cocked position and a fired position, the piston head moveably connected to the piston body to be longitudinally displaceable relative to the piston body between a first distance in the cocked position and a shorter second distance in the fired position, the piston head including a seal, the seal forming a sealed interface with an inside surface of the compression tube; and
(c) a radially expandable bushing contacting the piston head and the piston body, the bushing radially expanding in response to relative longitudinal movement of the piston body towards the piston head, the bushing having a first configuration defining a first radius in the cocked position of the compression piston and a second configuration defining a greater second radius in the fired position of the compression piston, the first radius sized to preclude contact with the inside surface of the compression tube and the second radius sized to contact the inside surface of the compression tube.

6. The airgun of claim 5 , wherein one of the piston head and the piston body include a plurality of radially projecting tail guides.

7. The airgun of claim 6 , wherein the plurality of radially projecting tail guides locate a portion of the piston body relative to an inner surface of a compression tube.

8. The airgun of claim 5 , wherein the piston body has a greater weight than the piston head.

9. The airgun of claim 5 , wherein the seal is selected to provide a sealing interface with an adjacent compression tube.

10. The airgun of claim 5 , further comprising a spring contacting one of the piston body, the piston head and the bushing.

11. The airgun of claim 5 , wherein the spring is a gas spring having a gas spring body defining a sealed interior chamber containing a compressed gas and a gas spring piston extending into and moveable relative to the sealed interior chamber, the interior chamber retaining the compressed gas when the gas spring piston moves.

12. A method comprising:
(a) disposing a radially expandable bushing on a compression piston, the compression piston sized to be slideably disposed within a compression tube of an airgun between a cocked position and a fired position, the compression piston having (i) a piston head including a piston seal and (ii) a piston body, wherein the bushing is intermediate the piston head and the piston body, the bushing expanding from a first radius in the cocked position, the first radius sized to preclude contact with an inside surface of the compression tube to a greater second radius in the fired position, the second radius sized to contact the inner surface of the compression tube of the airgun in response to longitudinal displacement of the piston head relative to the piston body;
(b) locating the compression piston and the bushing at least partially within the compression tube of the airgun; and
(c) mounting a spring in the airgun to urge the compression piston to move within the compression tube from the cocked position to the fired position.

13. The method of claim 12 , wherein the spring is a coil spring.

14. The method of claim 12 , wherein the spring is a gas spring.

15. The method claim 14 , wherein the gas spring includes a gas spring body defining a sealed interior chamber containing a compressed gas and a gas spring piston extending into and moveable relative to the sealed interior chamber, the interior chamber retaining the compressed gas when the gas spring piston moves.

Assignees

• Crosman Corp

Inventors

• Hanson Jeffrey

Classifications

• F41B11/642 Primary

  the piston being spring operated · CPC title